Search results for: process capability index
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6738

Search results for: process capability index

5268 The Change in Management Accounting from an Institutional and Contingency Perspective: A Case Study for a Romanian Company

Authors: Gabriel Jinga, Madalina Dumitru

Abstract:

The objective of this paper is to present the process of change in management accounting in Romania, a former communist country from Eastern Europe. In order to explain this process, we used the contingency and institutional theories. We focused on the following directions: the presentation of the scientific context and motivation of this research and the case study. We presented the state of the art in the process of change in the management accounting from the international and national perspective. We also described the evolution of management accounting in Romania in the context of economic and political changes. An important moment was the fall of communism in 1989. This represents a starting point for a new economic environment and for new management accounting. Accordingly, we developed a case study which presented this evolution. The conclusion of our research was that the changes in the management accounting system of the company analysed occurred in the same time with the institutionalisation of some elements (e.g. degree of competition, training and competencies in management accounting). The management accounting system was modelled by the contingencies specific to this company (e.g. environment, industry, strategy).

Keywords: Management accounting, change, Romania, contingency and institutional theory.

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5267 Process Optimisation for Internal Cylindrical Rough Turning of Nickel Alloy 625 Weld Overlay

Authors: Lydia Chan, Islam Shyha, Dale Dreyer, John Hamilton, Phil Hackney

Abstract:

Nickel-based superalloys are generally known to be difficult to cut due to their strength, low thermal conductivity, and high work hardening tendency. Superalloy such as alloy 625 is often used in the oil and gas industry as a surfacing material to provide wear and corrosion resistance to components. The material is typically applied onto a metallic substrate through weld overlay cladding, an arc welding technique. Cladded surfaces are always rugged and carry a tough skin; this creates further difficulties to the machining process. The present work utilised design of experiment to optimise the internal cylindrical rough turning for weld overlay surfaces. An L27 orthogonal array was used to assess effects of the four selected key process variables: cutting insert, depth of cut, feed rate, and cutting speed. The optimal cutting conditions were determined based on productivity and the level of tool wear.

Keywords: Cylindrical turning, nickel superalloy, turning of overlay, weld overlay.

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5266 Risk Factors for Defective Autoparts Products Using Bayesian Method in Poisson Generalized Linear Mixed Model

Authors: Pitsanu Tongkhow, Pichet Jiraprasertwong

Abstract:

This research investigates risk factors for defective products in autoparts factories. Under a Bayesian framework, a generalized linear mixed model (GLMM) in which the dependent variable, the number of defective products, has a Poisson distribution is adopted. Its performance is compared with the Poisson GLM under a Bayesian framework. The factors considered are production process, machines, and workers. The products coded RT50 are observed. The study found that the Poisson GLMM is more appropriate than the Poisson GLM. For the production Process factor, the highest risk of producing defective products is Process 1, for the Machine factor, the highest risk is Machine 5, and for the Worker factor, the highest risk is Worker 6.

Keywords: Defective autoparts products, Bayesian framework, Generalized linear mixed model (GLMM), Risk factors.

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5265 Hot Deformability of Si-Steel Strips Containing Al

Authors: Mohamed Yousef, Magdy Samuel, Maha El-Meligy, Taher El-Bitar

Abstract:

The present work is dealing with 2% Si-steel alloy. The alloy contains 0.05% C as well as 0.85% Al. The alloy under investigation would be used for electrical transformation purposes. A heating (expansion) - cooling (contraction) dilation investigation was executed to detect the a, a+g, and g transformation temperatures at the inflection points of the dilation curve. On heating, primary a  was detected at a temperature range between room temperature and 687 oC. The domain of a+g was detected in the range between 687 oC and 746 oC. g phase exists in the closed g region at the range between 746 oC and 1043 oC. The domain of a phase appears again at a temperature range between 1043 and 1105 oC, and followed by secondary a at temperature higher than 1105 oC. A physical simulation of thermo-mechanical processing on the as-cast alloy was carried out. The simulation process took into consideration the hot flat rolling pilot plant parameters. The process was executed on the thermo-mechanical simulator (Gleeble 3500). The process was designed to include seven consecutive passes. The 1st pass represents the roughing stage, while the remaining six passes represent finish rolling stage. The whole process was executed at the temperature range from 1100 oC to 900 oC. The amount of strain starts with 23.5% at the roughing pass and decreases continuously to reach 7.5 % at the last finishing pass. The flow curve of the alloy can be abstracted from the stress-strain curves representing simulated passes. It shows alloy hardening from a pass to the other up to pass no. 6, as a result of decreasing the deformation temperature and increasing of cumulative strain. After pass no. 6, the deformation process enhances the dynamic recrystallization phenomena to appear, where the z-parameter would be high.

Keywords: Si-steel, hot deformability, critical transformation temperature, physical simulation, thermo-mechanical processing, flow curve, dynamic softening.

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5264 Evaluation Process for the Hardware Safety Integrity Level

Authors: Sung Kyu Kim, Yong Soo Kim

Abstract:

Safety instrumented systems (SISs) are becoming increasingly complex and the proportion of programmable electronic parts is growing. The IEC 61508 global standard was established to ensure the functional safety of SISs, but it was expressed in highly macroscopic terms. This study introduces an evaluation process for hardware safety integrity levels through failure modes, effects, and diagnostic analysis (FMEDA).FMEDA is widely used to evaluate safety levels, and it provides the information on failure rates and failure mode distributions necessary to calculate a diagnostic coverage factor for a given component. In our evaluation process, the components of the SIS subsystem are first defined in terms of failure modes and effects. Then, the failure rate and failure mechanism distribution are assigned to each component. The safety mode and detectability of each failure mode are determined for each component. Finally, the hardware safety integrity level is evaluated based on the calculated results.

Keywords: Safety instrumented system; Safety integrity level; Failure modes, effects, and diagnostic analysis; IEC 61508.

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5263 Differential Evolution Based Optimal Choice and Location of Facts Devices in Restructured Power System

Authors: K. Balamurugan, V. Dharmalingam, R. Muralisachithanandam, R. Sankaran

Abstract:

This paper deals with the optimal choice and location of FACTS devices in deregulated power systems using Differential Evolution algorithm. The main objective of this paper is to achieve the power system economic generation allocation and dispatch in deregulated electricity market. Using the proposed method, the locations of the FACTS devices, their types and ratings are optimized simultaneously. Different kinds of FACTS devices such as TCSC and SVC are simulated in this study. Furthermore, their investment costs are also considered. Simulation results validate the capability of this new approach in minimizing the overall system cost function, which includes the investment costs of the FACTS devices and the bid offers of the market participants. The proposed algorithm is an effective and practical method for the choice and location of suitable FACTS devices in deregulated electricity market.

Keywords: FACTS Devices, Deregulated Electricity Market, Optimal Location, Differential Evolution, Mat Lab.

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5262 Alternative Approach toward Waste Treatment: Biodrying for Solid Waste in Malaysia

Authors: Nurul' Ain Ab Jalil, Hassan Basri

Abstract:

This paper reviews the objectives, methods and results of previous studies on biodrying of solid waste in several countries. Biodrying of solid waste is a novel technology in developing countries such as in Malaysia where high moisture content in organic waste makes the segregation process for recycling purposes complicated and diminishes the calorific value for the use of fuel source. In addition, the high moisture content also encourages the breeding of vectors and disease-bearing animals. From the laboratory results, the average moisture content of organic waste, paper, plastics and metals are 58.17%, 37.93%, 29.79% and 1.03% respectively for UKM campus. Biodrying of solid waste is a simple method of waste treatment as well as a cost-efficient technology to dry the solid waste. The process depends on temperature monitoring and air flow control along with the natural biodegradable process of organic waste. This review shows that the biodrying of solid waste method has high potential in treatment and recycling of solid waste, be useful for biodrying study and implementation in Malaysia.

Keywords: Biodrying of solid waste, Organic waste, Fuel source.

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5261 Hybrid Antenna Array with the Bowtie Elements for Super-Resolution and 3D Scanning Radars

Authors: Somayeh Komeylian

Abstract:

The antenna arrays for the entire 3D spherical coverage have been developed for their potential use in variety of applications such as radars and body-worn devices of the body area networks. In this study, we have rigorously revamped the hybrid antenna array using the optimum geometry of bowtie elements for achieving a significant improvement in the angular discrimination capability as well as in separating two adjacent targets. In this scenario, we have analogously investigated the effectiveness of increasing the virtual array length in fostering and enhancing the directivity and angular resolution in the 10 GHz frequency. The simulation results have extensively verified that the proposed antenna array represents a drastic enhancement in terms of size, directivity, side lobe level (SLL) and, especially resolution compared with the other available geometries. We have also verified that the maximum directivities of the proposed hybrid antenna array represent the robustness to the all  variations, which is accompanied by the uniform 3D scanning characteristic.

Keywords: Bowtie antenna, hybrid antenna array, array signal processing, body area networks.

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5260 Modeling of Oxygen Supply Profiles in Stirred-Tank Aggregated Stem Cells Cultivation Process

Authors: Vytautas Galvanauskas, Vykantas Grincas, Rimvydas Simutis

Abstract:

This paper investigates a possible practical solution for reasonable oxygen supply during the pluripotent stem cells expansion processes, where the stem cells propagate as aggregates in stirred-suspension bioreactors. Low glucose and low oxygen concentrations are preferred for efficient proliferation of pluripotent stem cells. However, strong oxygen limitation, especially inside of cell aggregates, can lead to cell starvation and death. In this research, the oxygen concentration profile inside of stem cell aggregates in a stem cell expansion process was predicted using a modified oxygen diffusion model. This profile can be realized during the stem cells cultivation process by manipulating the oxygen concentration in inlet gas or inlet gas flow. The proposed approach is relatively simple and may be attractive for installation in a real pluripotent stem cell expansion processes.

Keywords: Aggregated stem cells, dissolved oxygen profiles, modeling, stirred-tank, 3D expansion.

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5259 Numerical Simulation for Self-Loosening Phenomenon Analysis of Bolt Joint under Vibration

Authors: Long Kim Vu, Ban Dang Nguyen

Abstract:

In this paper, the finite element method (FEM) is utilized to simulate the comprehensive process including tightening, releasing and self-loosening of a bolt joint under transverse vibration. Following to the accurate geometry of helical threads, an absolutely hexahedral meshing is implemented. The accuracy of simulation process is verified and validated by comparison with the experimental results on clamping force-vibration relationship, which shows the sufficient correlation. Further analysis with different amplitude and frequency of transverse vibration is done to determine the dominant factor inducing the failure.

Keywords: Bolt self-loosening, contact state, FEM, transverse vibration.

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5258 Structural Cost of Optimized Reinforced Concrete Isolated Footing

Authors: Mohammed S. Al-Ansari

Abstract:

This paper presents an analytical model to estimate the cost of an optimized design of reinforced concrete isolated footing base on structural safety. Flexural and optimized formulas for square and rectangular footingare derived base on ACI building code of design, material cost and optimization. The optimization constraints consist of upper and lower limits of depth and area of steel. Footing depth and area of reinforcing steel are to be minimized to yield the optimal footing dimensions. Optimized footing materials cost of concrete, reinforcing steel and formwork of the designed sections are computed. Total cost factor TCF and other cost factors are developed to generalize and simplify the calculations of footing material cost. Numerical examples are presented to illustrate the model capability of estimating the material cost of the footing for a desired axial load.

Keywords: Footing, Depth, Concrete, Steel, Formwork, Optimization, Material cost, Cost Factors.

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5257 Electromagnetic Imaging of Inhomogeneous Dielectric Cylinders Buried in a Slab Mediumby TE Wave Illumination

Authors: Chung-Hsin Huang, Chien-Ching Chiu, Chun Jen Lin

Abstract:

The electromagnetic imaging of inhomogeneous dielectric cylinders buried in a slab medium by transverse electric (TE) wave illumination is investigated. Dielectric cylinders of unknown permittivities are buried in second space and scattered a group of unrelated waves incident from first space where the scattered field is recorded. By proper arrangement of the various unrelated incident fields, the difficulties of ill-posedness and nonlinearity are circumvented, and the permittivity distribution can be reconstructed through simple matrix operations. The algorithm is based on the moment method and the unrelated illumination method. Numerical results are given to demonstrate the capability of the inverse algorithm. Good reconstruction is obtained even in the presence of additive Gaussian random noise in measured data. In addition, the effect of noise on the reconstruction result is also investigated.

Keywords: Slab Medium, Unrelated Illumination Method, TEWave Illumination, Inhomogeneous Cylinders.

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5256 A Hybrid Overset Algorithm for Aerodynamic Problems with Moving Objects

Authors: S. M. H. Karimian, F. S. Salehi, H. Alisadeghi

Abstract:

A two-dimensional moving mesh algorithm is developed to simulate the general motion of two rotating bodies with relative translational motion. The grid includes a background grid and two sets of grids around the moving bodies. With this grid arrangement rotational and translational motions of two bodies are handled separately, with no complications. Inter-grid boundaries are determined based on their distances from two bodies. In this method, the overset concept is applied to hybrid grid, and flow variables are interpolated using a simple stencil. To evaluate this moving mesh algorithm unsteady Euler flow is solved for different cases using dual-time method of Jameson. Numerical results show excellent agreement with experimental data and other numerical results. To demonstrate the capability of present algorithm for accurate solution of flow fields around moving bodies, some benchmark problems have been defined in this paper.

Keywords: Moving mesh, Overset grid, Unsteady Euler, Relative motion.

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5255 A Case Study: Teachers Education Program in a Global Context

Authors: In Hoi Lee, Seong Baeg Kim, Je Eung Jeon, Gwang Yong Choi, Joo Sub Lee, Ik Sang Kim

Abstract:

Recently, the interest of globalization in the field of  teacher education has increased. In the U.S., the government is trying  to enhance the quality of education through a global approach in  education. To do so, the schools in the U.S. are recruiting teachers with  global capability from countries like Korea where competent teachers  are being trained. Meanwhile, in the case of Korea, although excellent  teachers have been cultivated every year, due to a low birth rate it is  not easy to become a domestic teacher. To solve the trouble that the  two countries are facing, the study first examines the demand and  necessity of globalization in the field of teacher education between  Korea and the U.S. Second, we propose a new project, called the  ‘Global Teachers University (GTU)’ program to satisfy the demands  of both countries. Finally, we provide its implications to build the  future educational cooperation for teacher training in a global context.

Keywords: Educational cooperation, globalization, teachers education program, teacher training institutions.

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5254 Some Remarkable Properties of a Hopfield Neural Network with Time Delay

Authors: Kelvin Rozier, Vladimir E. Bondarenko

Abstract:

It is known that an analog Hopfield neural network with time delay can generate the outputs which are similar to the human electroencephalogram. To gain deeper insights into the mechanisms of rhythm generation by the Hopfield neural networks and to study the effects of noise on their activities, we investigated the behaviors of the networks with symmetric and asymmetric interneuron connections. The neural network under the study consists of 10 identical neurons. For symmetric (fully connected) networks all interneuron connections aij = +1; the interneuron connections for asymmetric networks form an upper triangular matrix with non-zero entries aij = +1. The behavior of the network is described by 10 differential equations, which are solved numerically. The results of simulations demonstrate some remarkable properties of a Hopfield neural network, such as linear growth of outputs, dependence of synchronization properties on the connection type, huge amplification of oscillation by the external uniform noise, and the capability of the neural network to transform one type of noise to another.

Keywords: Chaos, Hopfield neural network, noise, synchronization

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5253 Risk Evaluation of Information Technology Projects Based on Fuzzy Analytic Hierarchal Process

Authors: H. Iranmanesh, S. Nazari Shirkouhi, M. R. Skandari

Abstract:

Information Technology (IT) projects are always accompanied by various risks and because of high rate of failure in such projects, managing risks in order to neutralize or at least decrease their effects on the success of the project is strongly essential. In this paper, fuzzy analytical hierarchy process (FAHP) is exploited as a means of risk evaluation methodology to prioritize and organize risk factors faced in IT projects. A real case of IT projects, a project of design and implementation of an integrated information system in a vehicle producing company in Iran is studied. Related risk factors are identified and then expert qualitative judgments about these factors are acquired. Translating these judgments to fuzzy numbers and using them as an input to FAHP, risk factors are then ranked and prioritized by FAHP in order to make project managers aware of more important risks and enable them to adopt suitable measures to deal with these highly devastative risks.

Keywords: Information technology projects, Risk evaluation, Analytic hierarchal process, fuzzy logic.

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5252 Lithofacies Classification from Well Log Data Using Neural Networks, Interval Neutrosophic Sets and Quantification of Uncertainty

Authors: Pawalai Kraipeerapun, Chun Che Fung, Kok Wai Wong

Abstract:

This paper proposes a novel approach to the question of lithofacies classification based on an assessment of the uncertainty in the classification results. The proposed approach has multiple neural networks (NN), and interval neutrosophic sets (INS) are used to classify the input well log data into outputs of multiple classes of lithofacies. A pair of n-class neural networks are used to predict n-degree of truth memberships and n-degree of false memberships. Indeterminacy memberships or uncertainties in the predictions are estimated using a multidimensional interpolation method. These three memberships form the INS used to support the confidence in results of multiclass classification. Based on the experimental data, our approach improves the classification performance as compared to an existing technique applied only to the truth membership. In addition, our approach has the capability to provide a measure of uncertainty in the problem of multiclass classification.

Keywords: Multiclass classification, feed-forward backpropagation neural network, interval neutrosophic sets, uncertainty.

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5251 Educating Students in Business Process Management with Simulation Games

Authors: Vesna Bosilj Vuksic, Mirjana Pejic Bach, Tomislav Hernaus

Abstract:

The aim of this paper is to present a framework for empirical investigation of the effectiveness of simulation games for student learning of BPM concept. A future research methodology is explained and a normative model that extends the standard TAM model by introducing latent and mediating variables into the relationship between independent variables and dependent variable is developed. Future research propositions are defined in order to examine the benefits that can be achieved through the use of BPM simulation games in ERP courses.

Keywords: Business process management, simulation games, education, technology acceptance model.

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5250 The Effect of Nose Radius on Cutting Force and Temperature during Machining Titanium Alloy (Ti-6Al-4V)

Authors: Moaz H. Ali, M. N. M. Ansari

Abstract:

This paper presents a study the effect of nose radius (Rz-mm) on cutting force components and temperatures during the machining simulation in an orthogonal cutting process for titanium alloy (Ti-6Al-4V). The cutting process was performed at various nose radiuses (Rz-mm) while the depth of cut (d-mm), feed rate (fmm/ tooth) and cutting speed (vc-m/ min) were remained constant. The main cutting force (Fc), feed cutting force (Ft) and temperatures were estimated by using finite element modeling (FEM) through ABAQUS/EXPLICIT software and the simulation was developed the two-dimension via an orthogonal cutting process during machining titanium alloy (Ti-6Al-4V). The results led to the conclusion that the nose radius (Rz-mm) has affected directly on the cutting force components. However, temperature gave no indication or has no significant relation with nose radius during machining titanium alloy (Ti-6Al-4V). Hence, any increase or decrease in the nose radius (Rzmm) during machining operation led to effect on the cutting forces and thus it will be effective on surface finish, quality, and quantity of products.

Keywords: Finite element modeling (FEM), nose radius, cutting force, temperature, titanium alloy (Ti-6Al-4V).

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5249 Self Organizing Analysis Platform for Wear Particle

Authors: Qurban A. Memon, Mohammad S. Laghari

Abstract:

Integration of system process information obtained through an image processing system with an evolving knowledge database to improve the accuracy and predictability of wear particle analysis is the main focus of the paper. The objective is to automate intelligently the analysis process of wear particle using classification via self organizing maps. This is achieved using relationship measurements among corresponding attributes of various measurements for wear particle. Finally, visualization technique is proposed that helps the viewer in understanding and utilizing these relationships that enable accurate diagnostics.

Keywords: Neural Network, Relationship Measurement, Selforganizing Clusters, Wear Particle Analysis.

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5248 Implementation of TinyHash based on Hash Algorithm for Sensor Network

Authors: HangRok Lee, YongJe Choi, HoWon Kim

Abstract:

In recent years, it has been proposed security architecture for sensor network.[2][4]. One of these, TinySec by Chris Kalof, Naveen Sastry, David Wagner had proposed Link layer security architecture, considering some problems of sensor network. (i.e : energy, bandwidth, computation capability,etc). The TinySec employs CBC_mode of encryption and CBC-MAC for authentication based on SkipJack Block Cipher. Currently, This TinySec is incorporated in the TinyOS for sensor network security. This paper introduces TinyHash based on general hash algorithm. TinyHash is the module in order to replace parts of authentication and integrity in the TinySec. it implies that apply hash algorithm on TinySec architecture. For compatibility about TinySec, Components in TinyHash is constructed as similar structure of TinySec. And TinyHash implements the HMAC component for authentication and the Digest component for integrity of messages. Additionally, we define the some interfaces for service associated with hash algorithm.

Keywords: sensor network security, nesC, TinySec, TinyOS, Hash, HMAC, integrity

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5247 Motion Planning and Control of a Swarm of Boids in a 3-Dimensional Space

Authors: Bibhya Sharma, Jito Vanualailai, Jai Raj

Abstract:

In this paper, we propose a solution to the motion planning and control problem for a swarm of three-dimensional boids. The swarm exhibit collective emergent behaviors within the vicinity of the workspace. The capability of biological systems to autonomously maneuver, track and pursue evasive targets in a cluttered environment is vastly superior to any engineered system. It is considered an emergent behavior arising from simple rules that are followed by individuals and may not involve any central coordination. A generalized, yet scalable algorithm for attraction to the centroid and inter-individual swarm avoidance is proposed. We present a set of new continuous time-invariant velocity control laws, formulated via the Lyapunov-based control scheme for target attraction and collision avoidance. The controllers provide a collision-free trajectory. The control laws proposed in this paper also ensures practical stability of the system. The effectiveness of the control laws is demonstrated via computer simulations.

Keywords: Swarm, Practical stability, Motion planning.

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5246 Periodic Storage Control Problem

Authors: Ru-Shuo Sheu, Han-Hsin Chou, Te-Shyang Tan

Abstract:

Considering a reservoir with periodic states and different cost functions with penalty, its release rules can be modeled as a periodic Markov decision process (PMDP). First, we prove that policy- iteration algorithm also works for the PMDP. Then, with policy- iteration algorithm, we obtain the optimal policies for a special aperiodic reservoir model with two cost functions under large penalty and give a discussion when the penalty is small.

Keywords: periodic Markov decision process, periodic state, policy-iteration algorithm.

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5245 Learning the Dynamics of Articulated Tracked Vehicles

Authors: Mario Gianni, Manuel A. Ruiz Garcia, Fiora Pirri

Abstract:

In this work, we present a Bayesian non-parametric approach to model the motion control of ATVs. The motion control model is based on a Dirichlet Process-Gaussian Process (DP-GP) mixture model. The DP-GP mixture model provides a flexible representation of patterns of control manoeuvres along trajectories of different lengths and discretizations. The model also estimates the number of patterns, sufficient for modeling the dynamics of the ATV.

Keywords: Dirichlet processes, Gaussian processes, robot control learning, tracked vehicles.

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5244 Key Competences in Economics and Business Field: The Employers’ Side of the Story

Authors: Bruno Škrinjarić

Abstract:

Rapid technological developments and increase in organizations’ interdependence on international scale are changing the traditional workplace paradigm. A key feature of knowledge based economy is that employers are looking for individuals that possess both specific academic skills and knowledge, and also capability to be proactive and respond to problems creatively and autonomously. The focus of this paper is workers with Economics and Business background and its goals are threefold: (1) to explore wide range of competences and identify which are the most important to employers; (2) to investigate the existence and magnitude of gap between required and possessed level of a certain competency; and (3) to inquire how this gap is connected with performance of a company. A study was conducted on a representative sample of Croatian enterprises during the spring of 2016. Results show that generic, rather than specific, competences are more important to employers and the gap between the relative importance of certain competence and its current representation in existing workforce is greater for generic competences than for specific. Finally, results do not support the hypothesis that this gap is correlated with firms’ performance.

Keywords: Competency gap, competency matching, key competences, firm performance.

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5243 Adaptive MPC Using a Recursive Learning Technique

Authors: Ahmed Abbas Helmy, M. R. M. Rizk, Mohamed El-Sayed

Abstract:

A model predictive controller based on recursive learning is proposed. In this SISO adaptive controller, a model is automatically updated using simple recursive equations. The identified models are then stored in the memory to be re-used in the future. The decision for model update is taken based on a new control performance index. The new controller allows the use of simple linear model predictive controllers in the control of nonlinear time varying processes.

Keywords: Adaptive control, model predictive control, dynamic matrix control, online model identification

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5242 Experimental and Numerical Study of Ultra-High-Performance Fiber-Reinforced Concrete Column Subjected to Axial and Eccentric Loads

Authors: Chengfeng Fang, Mohamed Ali Sadakkathulla, Abdul Sheikh

Abstract:

Ultra-high-performance fiber reinforced concrete (UHPFRC) is a specially formulated cement-based composite characterized with an ultra-high compressive strength (fc = 240 MPa) and a low water-cement ratio (W/B= 0.2). With such material characteristics, UHPFRC is favored for the design and constructions of structures required high structural performance and slender geometries. Unlike conventional concrete, the structural performance of members manufactured with UHPFRC has not yet been fully studied, particularly, for UHPFRC columns with high slenderness. In this study, the behaviors of slender UHPFRC columns under concentric or eccentric load will be investigated both experimentally and numerically. Four slender UHPFRC columns were tested under eccentric loads with eccentricities, of 0 mm, 35 mm, 50 mm, and 85 mm, respectively, and one UHPFRC beam was tested under four-point bending. Finite element (FE) analysis was conducted with concrete damage plasticity (CDP) modulus to simulating the load-middle height or middle span deflection relationships and damage patterns of all UHPFRC members. Simulated results were compared against the experimental results and observation to gain the confidence of FE model, and this model was further extended to conduct parametric studies, which aim to investigate the effects of slenderness regarding failure modes and load-moment interaction relationships. Experimental results showed that the load bearing capacities of the slender columns reduced with an increase in eccentricity. Comparisons between load-middle height and middle span deflection relationships as well as damage patterns of all UHPFRC members obtained both experimentally and numerically demonstrated high accuracy of the FE simulations. Based on the available FE model, the following parametric study indicated that a further increase in the slenderness of column resulted in significant decreases in the load-bearing capacities, ductility index, and flexural bending capacities.

Keywords: Eccentric loads, ductility index, RC column, slenderness, UHPFRC.

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5241 Assembly Process Algorithms of Flexible Cell

Authors: M. Kusá, M. Matúšová, A. Javorová, K. Velí

Abstract:

This paper deals about four items assembly process of linear drive. This assembly will be realized in flexible assembly cell on Institute of Manufacturing Systems and Applied Mechanics. There is defined manufacturing cell, individual actuators created our flexible cell. Next chapter is about control type, detailed describe a sequence control type, which will be used in mentioned flexible assembly cell. All cell control is divided in individual steps instructions. There instructions illustrate table number III.

Keywords: assembly, flexible cell, sequence control

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5240 Material Handling Equipment Selection using Hybrid Monte Carlo Simulation and Analytic Hierarchy Process

Authors: Amer M. Momani, Abdulaziz A. Ahmed

Abstract:

The many feasible alternatives and conflicting objectives make equipment selection in materials handling a complicated task. This paper presents utilizing Monte Carlo (MC) simulation combined with the Analytic Hierarchy Process (AHP) to evaluate and select the most appropriate Material Handling Equipment (MHE). The proposed hybrid model was built on the base of material handling equation to identify main and sub criteria critical to MHE selection. The criteria illustrate the properties of the material to be moved, characteristics of the move, and the means by which the materials will be moved. The use of MC simulation beside the AHP is very powerful where it allows the decision maker to represent his/her possible preference judgments as random variables. This will reduce the uncertainty of single point judgment at conventional AHP, and provide more confidence in the decision problem results. A small business pharmaceutical company is used as an example to illustrate the development and application of the proposed model.

Keywords: Analytic Hierarchy Process (AHP), Materialhandling equipment selection, Monte Carlo simulation, Multi-criteriadecision making

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5239 Strategies of Entrepreneurs to Collaborate with Alliances for Commercializing Technology and New Product Innovation: A Practical Learning in Thailand

Authors: Kusumaphorn Sompong, Helen Lawton Smith, Barbara Igel

Abstract:

This paper provides a key driver-based conceptual framework that can be used to improve a firm-s success in commercializing technology and in new product innovation resulting from collaboration with other organizations through strategic alliances. Based on a qualitative study using an interview approach, strategic alliances of entrepreneurs in the food processing industry in Thailand are explored. This paper describes factors affecting decisions to collaborate through alliances. It identifies four issues: maintaining the efficiency of the value chain for production capability, adapting to present and future competition, careful assessment of value of outcomes, and management of innovation. We consider five driving factors: resource orientation, assessment of risk, business opportunity, sharing of benefits and confidence in alliance partners. These factors will be of interest to entrepreneurs and policy makers with regard to further understanding of the direction of business strategies.

Keywords: Managing collaboration, strategic alliance, technology commercialization, innovation.

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