Operations Research, Systems Engineering and Industrial Engineering Commons^™

Improving The Design Of Low Volume Sealed Roads In Tanzania, Mfinanga A

Tanzania Journal of Engineering and Technology (TJET)

The main objective of the study was to identify appropriate road designs for Low Volume Sealed Roads (LVSRs) with the aim of improving the design of such roads in Tanzania. The study was conducted in Dar es Salaam and Morogoro regions in Tanzania where data for LVSRs were collected from primary and secondary sources in the two regions. The study found that by using an improved pavement design method specifically meant for LVSRs results in cost savings for LVSRs of up to 51% compared with the conventional method of pavement design in Tanzania. The study recommends that the pavement design …

The Effect Of Rotation And Temperature On The Inhibition Performance Of Cashew (Anacardium Occidentale L.) Nut Shell Liquid On Co2 Corrosion Of Carbon Steel, J Mutasingwa

Tanzania Journal of Engineering and Technology (TJET)

A natural extract of cashew nut shells, Cashew Nut Shell Liquid (CNSL) was investigated as a corrosion inhibitor for carbon steel in 3% NaCl solutions saturated with CO2 gas using electrochemical techniques (i.e. potentiodynamic polarization and ac-impedance). The investigation was performed at different temperatures under static and dynamic conditions using a Rotating Disk Electrode (RDE). It was found that CNSL reduces the electrochemical processes taking place on carbon steel undergoing corrosion. The percentage inhibitor efficiency increases with increase in CNSL concentration and decreases with rise in temperature. Better performance at low CNSL concentration was registered under dynamic conditions and room …

Potential Use Of Waterguard As A Disinfectant For Domestic Water Use, Yohana L

Tanzania Journal of Engineering and Technology (TJET)

been identified as an alternative method for treatment of domestic drinking water. The aim of this study was to investigate the effectiveness of Water Guard in disinfecting drinking water from different sources drawn from Kinondoni district, Dar es Salaam as well as to establish appropriate dosage that can be used during the treatment. Results showed that, a dose of 4.0mL per 20 litrer of water guard is sufficient for disinfection of urban water sources. The above prescribed doses provide 100% disinfection efficiency with residue chlorine of less than 0.3mg/l. Water with turbidity values of 30-35 NTU, chlorine dosage of 8mL/20 …

Investigation Of The Effect Of Particle Size On Groundnut-Oil Solvent Extraction, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

An investigation of the effect of particle size on the performance of vegetable oil recovery by solvent extraction is reported. Experiments were conducted using soxhlet extractor, groundnuts and n-hexane. Samples were grouped into mean particle sizes of 0.25, 0.75, 1.3, 3.3, and 7.5 mm using standard sieves. The effect of particle size was studied for extraction time intervals of 1, 2, 3, 4, 5 and 8 hours. The oil yield, oil recovered per kg solvent used, kg solvent lost per unit time, and the rate of extraction (kg oil recovered per hour) decreased with increasing particle size. Meanwhile, the percent …

The Systemic Nature Of Action Learning Programmes, G Mwaluko

Tanzania Journal of Engineering and Technology (TJET)

A lot of attention has been paid on action learning in the last four decades or so and the success of such programmes has also been widely publicized. But why have these programmes been so effective in helping organizations cope with change? Many authors state that the success of such programmes is due to the fact that they link learning to actions. Yet others claim that action learning programmes succeed because they involve employee empowerment and provide a much greater learning curve. In this paper the authors hold that action learning programmes succeed because they are partly systemic and can …

Analytical Modeling Of A Large Local Area Network - Part I: Internet Traffic Characterization, Mathew Luhanga

Tanzania Journal of Engineering and Technology (TJET)

The goal of both IP network operators and the end users is to get the highest performance from the system for a given cost. This makes Performance a key criterion in the design, procurement, and use of computer and communication systems. In order to address problems associated with performance degradation of operational communications systems, over the last decade, traffic engineering techniques have emerged in an attempt to optimize communication systems’ performance and ensure more efficient use of their resources. One of these techniques is analytical modeling. Analytic performance models are an excellent tool for quickly evaluating the performance of operational …

Identification Of Unbalanced Forces And Foundation Parameters Of Rotating Machines From Vibration Measurements, Nalitolela G

Tanzania Journal of Engineering and Technology (TJET)

A technique is described to use measured vibration data of a rotating machine and its foundation to identify unbalanced forces, stiffness and damping parameters of the mountings, and the parameters of the foundation. It is based on an idealisation treating the rotor, the machine structure and the foundation as rigid masses supported by springs and dampers. Operational vibration data of the machine and its foundation before and after the rotating unbalanced forces are perturbed by adding unbalanced mass to the rotor are used in the identification procedure. Once the parameters are identified, dynamic forces transmitted to the foundation can be …

Design And Development Of A Prototype For A Web-Based Interface For Online Material For Tanzanian Youth, Mjema A.M

Tanzania Journal of Engineering and Technology (TJET)

A prototype of a web-based interface for an online database was developed to be used by youth organizations in Dar-es-Salaam. A participatory approach involving secondary students in the identification of user interface requirements, in designing and testing the prototype was used. A questionnaire was designed and manned in seven secondary schools in Dar-es-Salaam to estimate the Internet usage. Interviews were conducted to countercheck the questionnaire responses. The interview and the questionnaire helped to come up with a set of user requirements for the web-based interface of an online information search. From the specifications of the user requirements the author was …

Acuta Enews December 2008, Vol. 37, No. 12

ACUTA Newsletters

In This Issue

From the President.............. Corinne Hoch, Columbia, Univ., ACUTA President

Board Report............. Riny Ledgerwood, San Diego State Univ., ACUTA Secretary/Treasurer

DC Update............. Dave Ostrom, Washington State Univ. (retired)

Info Links........... Randy Hayes, Univ. of Northern Iowa

ACUTA Guide to Products and Services: Keep It Handy, Use It Often

ACUTA Web Seminar: Wireless Andrew 2.0

"Earthbottle" Brought to you by Clemson

Check It Out: Press Releases... Job Postings.... RFIs/RFPs

Holiday Greetings from the ACUTA Staff

Welcome New Members

Xftsp: A Tool For Time Series Prediction By Means Of Fuzzy Inference Systems, Federico Montesino, Amaury Lendasse, Ángel Barriga

Engineering Management and Systems Engineering Faculty Research & Creative Works

A New Software Tool for Time Series Prediction by Means of Fuzzy Inference Systems is Reported. This Tool, Named XFTSP, implements a Novel Methodology for Time Series Prediction based on Methods for Automatic Fuzzy Systems Identification and Supervised Learning Combined with Statistical Methods for Nonparametric Residual Variance Estimation. XFTSP is Designed as a Tool Integrated in the Xfuzzy Development Environment for Fuzzy Systems. Experiments Carried Out on a Number of Time Series Benchmarks Show the Advantages of XFTSP in Terms of Both Accuracy and Computational Requirements as Compared Against Least-Squared Support Vector Machines, an Established Technique in the Field of …

On Step Sizes, Stochastic Shortest Paths, And Survival Probabilities In Reinforcement Learning, Abhijit Gosavi

Engineering Management and Systems Engineering Faculty Research & Creative Works

Reinforcement learning (RL) is a simulation-based technique useful in solving Markov decision processes if their transition probabilities are not easily obtainable or if the problems have a very large number of states. We present an empirical study of (i) the effect of step-sizes (learning rules) in the convergence of RL algorithms, (ii) stochastic shortest paths in solving average reward problems via RL, and (iii) the notion of survival probabilities (downside risk) in RL. We also study the impact of step sizes when function approximation is combined with RL. Our experiments yield some interesting insights that will be useful in practice …

Comparing Component Functional Template Modeling Experimental Results In An Undergraduate Level Engineering Design Course, Daniel Abbott, Katie Grantham Lough

Engineering Management and Systems Engineering Faculty Research & Creative Works

Component functional templates are a foundational tool, for the functional modeling method, that novice users can implement to develop functional modeling skills and produce better results by not requiring the modeler to have extensive background knowledge in the method. the templates provide common function layouts of ordinary electromechanical components that are based on historic data collected from design information on a wide range of consumer products. a previous experiment has been performed on a sophomore level design class to assess the change in quality between functional modeling results with and without the use of component functional templates. to address further …

Design For Manufacturing (Dfm) Methodology To Implement Friction Stir Welding (Fsw) For Automobile Chassis Fabrication, Harish Bagaitkar, Venkat Allada

Engineering Management and Systems Engineering Faculty Research & Creative Works

The manufacturing functional feasibility of implementing Friction Stir Welding (FSW) for automobile chassis fabrication is discussed using a case study. in the case study, the Design for Manufacturing (DFM) principles are applied to manufacture an aluminum automobile chassis. Various DFM issues are addressed while proposing the FSW technique as an alternative to laser welding and metal inert gas welding techniques. DFM guidelines involving joint design change, component geometries, and component elimination are discussed in this paper. by making appropriate changes in the component geometries and joint designs and eliminating some components, more than 50% of the joints in the example …

A Model Based Fault Detection And Prognostic Scheme For Uncertain Nonlinear Discrete-Time Systems, Balaje T. Thumati, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A new fault detection and prognostics (FDP) framework is introduced for uncertain nonlinear discrete time system by using a discrete-time nonlinear estimator which consists of an online approximator. A fault is detected by monitoring the deviation of the system output with that of the estimator output. Prior to the occurrence of the fault, this online approximator learns the system uncertainty. In the event of a fault, the online approximator learns both the system uncertainty and the fault dynamics. A stable parameter update law in discrete-time is developed to tune the parameters of the online approximator. This update law is also …

Neural Network Output Feedback Control Of A Quadrotor Uav, Jagannathan Sarangapani, Travis Alan Dierks

Electrical and Computer Engineering Faculty Research & Creative Works

A neural network (NN) based output feedback controller for a quadrotor unmanned aerial vehicle (UAV) is proposed. The NNs are utilized in the observer and for generating virtual and actual control inputs, respectively, where the NNs learn the nonlinear dynamics of the UAV online including uncertain nonlinear terms like aerodynamic friction and blade flapping. It is shown using Lyapunov theory that the position, orientation, and velocity tracking errors, the virtual control and observer estimation errors, and the NN weight estimation errors for each NN are all semi-globally uniformly ultimately bounded (SGUUB) in the presence of bounded disturbances and NN functional …

Neural-Network-Based State Feedback Control Of A Nonlinear Discrete-Time System In Nonstrict Feedback Form, Pingan He, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a suite of adaptive neural network (NN) controllers is designed to deliver a desired tracking performance for the control of an unknown, second-order, nonlinear discrete-time system expressed in nonstrict feedback form. In the first approach, two feedforward NNs are employed in the controller with tracking error as the feedback variable whereas in the adaptive critic NN architecture, three feedforward NNs are used. In the adaptive critic architecture, two action NNs produce virtual and actual control inputs, respectively, whereas the third critic NN approximates certain strategic utility function and its output is employed for tuning action NN weights …

On Nonparametric Residual Variance Estimation, Elia Liitiäinen, Francesco Corona, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, the Problem of Residual Variance Estimation is Examined. the Problem is Analyzed in a General Setting Which Covers Non-Additive Heteroscedastic Noise under Non-Iid Sampling. to Address the Estimation Problem, We Suggest a Method based on Nearest Neighbor Graphs and We Discuss its Convergence Properties under the Assumption of a Hölder Continuous Regression Function. the Universality of the Estimator Makes It an Ideal Tool in Problems with Only Little Prior Knowledge Available. © 2008 Springer Science business Media, LLC.

Dynamic Analysis Of Less-Than-Truckload Shipments And Test Method To Simulate This Environment, Sher Paul Singh, E. Joneson, Jay Singh, G. Grewal

Industrial Technology and Packaging

This paper provides results from a comprehensive data measurement study that analyzed the vibration dynamics produced inside the trailers used for less-than truckload (LTL) shipments. The trailers used for this segment of the package transportation environment are very different in size and suspension than those used for full truckload shipments. This study measured the vertical, lateral and longitudinal vibration inside a trailer as a function of road surface. In addition, the study developed a video showing freight movement inside the trailer to determine physical displacement and shifting of the loads. A set of recommendations was developed to safely load and …

Optimal And Heuristic Resource Allocation Policies In Serial Production Systems, Ramesh Arumugam

All Theses

We have studied the optimal server allocation policies for a tandem queueing system under different system settings. Motivated by an industry project, we have studied a two stage tandem queueing system with arrival to the system and having two flexible servers capable of working at either of the stations. In our research, we studied the system under two different circumstances: modeling the system to maximize throughput without cost considerations, modeling the system to include switching and holding costs along with revenue for finished goods. In the maximizing throughput scenario, we considered two different types of server allocations: collaborative and non-collaborative. …

Effective Vr: Interplay Of Presence, Perception, Fidelity And Transfer Effects In The Development Of Inspection Training Simulators, Sajay Sadasivan

All Dissertations

Increased emphasis on aircraft inspection to ensure aviation safety has resulted in the need for a better trained workforce of aircraft maintenance personnel. Aircraft inspection is mostly visual in nature. Thus it has led to the development of computer simulators to train human inspectors performing the inspection task. However, the lack of immersion and interaction in such simulators has led to limited effectiveness and adoption. Using advances in graphics and virtual reality technology, there is an increase the sense of involvement in using these simulators. Though technology is available to provide higher levels of immersion, it is expensive. It is …

Distributing Complementary Resources Across Multiple Periods With Stochastic Demand, Shih-Fen Cheng, John Tajan, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

In this paper, we evaluate whether the robustness of a market mechanism that allocates complementary resources could be improved through the aggregation of time periods in which resources are consumed. In particular, we study a multi-round combinatorial auction that is built on a general equilibrium framework. We adopt the general equilibrium framework and the particular combinatorial auction design from the literature, and we investigate the benefits and the limitation of time-period aggregation when demand-side uncertainties are introduced. By using simulation experiments, we show that under stochastic conditions the performance variation of the process decreases as the time frame length (time …

Long-Term Prediction Of Time Series Using Nne-Based Projection And Op-Elm, Antti Sorjamaa, Yoan Miche, Robert Weiss, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

This Paper Proposes a Combination of Methodologies based on a Recent Development -Called Extreme Learning Machine (Elm)- Decreasing Drastically the Training Time of Nonlinear Models. Variable Selection is Beforehand Performed on the Original Dataset, using the Partial Least Squares (Pls) and a Projection based on Nonparametric Noise Estimation (NNE), to Ensure Proper Results by the Elm Method. Then, after the Network is First Created using the Original Elm, the Selection of the Most Relevant Nodes is Performed by using a Least Angle Regression (Lars) Ranking of the Nodes and a Leave-One-Out Estimation of the Performances, Leading to an Optimally Pruned …

A Computer-Based Economic Analysis For Manufacturing Process Selection, Manocher Djassemi

Industrial Technology and Packaging

An important part of financial planning in product development is considering whether the capital expenditures meet volume and cost goals. A good business plan should provide investors with the implications of process selection on the company's bottom line. It is estimated that there are least 1000 manufacturing processes and sub-processes. Considering the number of process choices and quantity of cost data, an economic analysis for process selection may pose a challenge for decision makers. This paper provides an insight to Ashby’s cost modeling method for generating an estimate of unit product cost. The cost model provides a broad indicator for …

Optimal Pruned K-Nearest Neighbors: Op-Knn - Application To Financial Modeling, Q. Yu, A. Sorjamaa, Y. Miche, Amaury Lendasse, Eric Séverin, A. Guillen, F. Mateo

Engineering Management and Systems Engineering Faculty Research & Creative Works

The Paper Proposes a Methodology Called OO-KNN, Which Builds a One Hidden-Layer Feedforward Neural Network, using Nearest Neighbors Neurons with Extremely Small Computational Time. the Main Strategy is to Select the Most Relevant Variables Beforehand, Then to Build the Model using KNN Kernels. Multi response Sparse Regression (MRSR) is Used as the Second Step in Order to Rank Each Kth Nearest Neighbor and Finally as a Third Step Leave-One-Out Estimation is Used to Select the Number of Neighbors and to Estimate the Generalization Performances. This New Methodology is Tested on a Toy Example and is Applied to Financial Modeling. © …

Fuzzy Inference Based Autoregressors For Time Series Prediction Using Nonparametric Residual Variance Estimation, Federico Montesino Pouzols, Amaury Lendasse, Angel Barriga

Engineering Management and Systems Engineering Faculty Research & Creative Works

We Apply Fuzzy Techniques for System Identification and Supervised Learning in Order to Develop Fuzzy Inference based Auto regressors for Time Series Prediction. an Automatic Methodology Framework that Combines Fuzzy Techniques and Statistical Techniques for Nonparametric Residual Variance Estimation is Proposed. Identification is Performed through the Learn from Examples Method Introduced by Wang and Mendel, While the Marquard-Levenberg Supervised Learning Algorithm is Then Applied for Tuning. Delta Test Residual Noise Estimation is Used in Order to Select the Best Subset of Inputs as Well as the Number of Linguistic Labels for the Inputs. Experimental Results for Three Time Series Prediction …

Drop Impact Dynamic Response Study Of Jedec Jesd22-B111 Test Board, Michael Krist, Jianbiao Pan, Andrew Farris, Nicolas Vickers

Industrial and Manufacturing Engineering

Mobile and handheld electronic devices are prone to being dropped. This drop event may result in failure of solder joints inside these devices. The need for RoHS compliant boards coupled with the demand for reliable electronics has resulted in the development of the JEDEC Standard JESD22-B111 to standardize the method of drop testing surface mount electronic components. However, there has been little study on the effects of additional mass on the board and rigidity of the board on drop test reliability. This paper examines the drop impact dynamic responses of the JEDEC JESD22-B111 board. Of interest are the effects of …

The Effect Of Ultrasonic Frequency On Gold Wire Bondability And Reliability, Jianbiao Pan, Minh-Nhat Le, Cuong Van Pham

Industrial and Manufacturing Engineering

This paper presents a systematic study on the effect of 120KHz ultrasonic frequency on the bondability and reliability of fine pitch gold wire bonding. The study was carried out on a thermosonic ball bonder that is allowed to easily switch between ultrasonic frequency of 60KHz and 120 KHz by changing the ultrasonic transducer and the ultrasonic generator. Bonding parameters were optimized through design of experiment methodology for four different cases: 25.4 μm wire at 60 kHz, 25.4 μm wire at 120 kHz, 17.8 μm wire at 60 kHz, and 17.8 μm wire at 120 kHz. The integrity of wire bonds …

Board Level Failure Analysis Of Chip Scale Package Drop Test Assemblies, Nicholas Vickers, Kyle Rauen, Andrew Farris, Jianbiao Pan

Industrial and Manufacturing Engineering

This paper presents the failure analysis results of board level drop tests. In this study, the test vehicle was designed according to the requirements of the Joint Electron Device Engineering Council (JEDEC) drop test board. The test vehicle was assembled with 15 chip scale packages (CSPs) each having 228 daisy-chained 0.5 mm pitch solder joints using Sn-3.0 wt% Ag-0.5 wt% Cu (SAC305) lead free solder. Assemblies were drop tested using three different peak accelerations of 900 G, 1500 G, 2900 G, with 0.7 ms, 0.5 ms, and 0.3 ms pulse durations, respectively. Scanning electron microscopy (SEM) with energy dispersive spectroscopy …

Acuta Enews November 2008, Vol. 37, No. 11

ACUTA Newsletters

In This lssue

From ACUTA Headquarters: FCC lssues Rules to lmplement NET 91 1 ACT........ Jeri Semer, CAE, Exec. Dir

Tech Talk: For Most, the Big Change on Campus ls Wireless.............Kevin Tanzillo, Dux PR

DC Update.............. Dove Ostrom, Washlngton State University

Nominate Now for ACUTA Board of Directors

Be a State/Province Coordinator

Teflon:A Dangerous Part of a High-Risk World.................Frank Bisbee, Wireville USA

Thanks to Exhibitors for 2008

lnfo Links ............. Randy Hayes, Univ. of Northern lowa

Board Report, October....................... Riny Ledgenuood, San Diego State Univ.

Welcome New Members

Check lt Out: RFls/RFPs, Job Postings, Press Releases

Summer Sessions Breakdown Of Course Dates And Time, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

This report highlights an exhaustive analysis of the hundreds of Summer Session courses to develop an understanding of when they occur during the day and during which of the four academic terms. The analysis shows that the most popular time for scheduling courses is between 9:30 am and noon for each of the four summer session terms. Given the limited number of general purpose classrooms on campus, accommodating faculty preference for rooms, buildings, and computer equipment is sometimes not possible during the most in demand course times. The results also showcase the potential for having summer courses four-day per week …