Engineering Commons^™

Modification Of Bonding Strength Test Of Wc Hvof Thermal Spray Coating On Rocket Nozzle, Bondan T. Sofyan, Haposan J. Pardede, Marizki Stefano, Edi Sofyan

Makara Journal of Technology

Modification of Bonding Strength Test of WC HVOF Thermal Spray Coating on Rocket Nozzle. One way to reduce structural weight of RX-100 rocket is by modifying the nozzle material and processing. Nozzle is the main target in weight reduction due to the fact that it contributes 30 % to the total weight of the structur. An alternative for this is by substitution of massive graphite, which is currently used as thermal protector in the nozzle, with thin layer of HVOF (High Velocity Oxy-Fuel) thermal spray layer. This paper presents the characterization of nozzle base material as well as the modification …

Development Of Fiber-Optic Humidity Sensor Probe With Gelatin Cladding, Akhiruddin Maddu, Kun Modjahidin, Sar Sardy, Hamdani Zain

Makara Journal of Technology

Development of Fiber-Optic Humidity Sensor Probe with Gelatin Cladding. Humidity sensor based on optical fiber with gelatin cladding has been developed. In this humidity sensor probe, the origin cladding of optical fiber is replaced by gelatin coating as humidity sensitive cladding. Testing of the optical fiber sensor probe was conducted by measuring of light intensity transmitted on the optical fiber probe for each variation of different humidity treatments. Response of the optical fiber sensor probe measured from 42%RH to 99%RH, the results show an optical transmission curve varied with relative humidity (RH). Optical transmission in the optical fiber probe increase …

A Reconfigurable Distributed Computing Fabric Exploiting Multilevel Parallelism, Charles L. Cathey, Jason D. Bakos, Duncan A. Buell

Faculty Publications

This paper presents a novel reconfigurable data flow processing architecture that promises high performance by explicitly targeting both fine- and course-grained parallelism. This architecture is based on multiple FPGAs organized in a scalable direct network that is substantially more interconnect-efficient than currently used crossbar technology. In addition, we discuss several ancillary issues and propose solutions required to support this architecture and achieve maximal performance for general-purpose applications; these include supporting IP, mapping techniques, and routing policies that enable greater flexibility for architectural evolution and code portability.

On The Performance Of Imt-2000 Communication Link Based On Stratospheric Platforms, Iskandar Iskandar, Shigeru Shimamoto

Makara Journal of Technology

A new means for providing wireless communication has been currently proposed. It is based on aerial vehicle known as High Altitude Platform or Stratospheric Platforms (SPF). The SPF will be operated at an altitude of 17-22 km above the ground. Therefore, the channel condition may be different compared with those of the conventional terrestrial or satellite wireless channel. In this paper, the channel propagation characteristic of such a system is firstly investigated by means of ray tracing algorithm. We emphasize our investigation in a typical urban environment, in which the mobile users mostly exist. We developed building block model for …

Analysis Of Technical Energy Losses By Using Simulation, Betrianis Betrianis, Randite Herawan

Makara Journal of Technology

Model is a representation of a system. Through model, it can be easier to forecast and control the changing of each element system. Electricity distribution is also a system. Losses are general problem that exist in a distribution network system. But with the right methods, specifically technical energy losses can be reduced in order to increase the efficiency. By making model of the distribution network, the value of technical energy losses in the whole network as well as in every line can be observed. Simulation can also be used to see all losses reduction alternatives. By comparing results from each …

Modeling Of Coupled-Tank System Using Fuzzy Takagi-Sugeno Model, Aries Subiantoro

Makara Journal of Technology

Modeling of Coupled-Tank System Using Fuzzy Takagi-Sugeno Model. This paper describes modeling of coupledtank system based on data measurement using fuzzy Takagi-Sugeno model. The fuzzy clustering method of Gustafson- Kessel algorithm is used to classify input-output data into several clusters based on distance similarity of a member of input-output data from center of cluster. The formed clusters are projected orthonormally into each linguistic variables of premise part to determine membership function of fuzzy Takagi-Sugeno model. By estimating data in each cluster, the consequent parameters of fuzzy Takagi-Sugeno model are calculated using weighted least-squares method. The resulted fuzzy Takagi-Sugeno model is …

Design Of Induction Motor Drive Without Velocity Sensor Using Current Vector Controller With Full And Reduced Observer Moving To Dq Axis, Ridwan Gunawan, Feri Yusivar, Wahidin Wahab, Zuhal A. Kadir

Makara Journal of Technology

Design of Induction Motor Drive Without Velocity Sensor Using Current Vector Controller with Full and Reduced Observer Moving to DQ Axis. The observer is used in estimation velocity sensor usually in α-β axis, therefore this situation will need an extra transformation when we want to add compensator because the flux model is in direct and quadrature-axis dq. Every used the transformation to make possible emerge an error. So in this simulation is used a method to estimate the velocity of induction motor drive with observer that is moved to dq-axis. The model of actual motor used is in alfa-beta axis, …

Hybrid Identification System With Arx And Fast Fourier Transform In Application Of A Quarter Of Vehicle Half Active Suspension, Noveri Lysbetti M, Antonius R.

Makara Journal of Technology

Hybrid Identification System with ARX and Fast Fourier Transform in Application of a Quarter of Vehicle Half Active Suspension. In a control system problem, identification system mechanism is a absolute thing, especially in adaptation controlling to disturbance changing. For that case, is needed an identification method which can identify the changing of disturbance in that system. The aim of this research is to give an alternative in system/plant identification which is a combination (hybrid) of ARX and Fast Fourier Transform. So, it is needed an algorithm design for identification process. In this case, the designed algorithm will be implemented in …

Fast Thermal Profiling Of Power Semiconductor Devices Using Fourier Techniques, J. J. Nelson, G. Venkataramanan, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

Accurate prediction of temperature variation of power semiconductor devices in power electronic circuits is important to obtain optimum designs and estimate reliability levels. Temperature estimation of power electronic devices has generally been performed using transient thermal equivalent circuits. In the presence of varying load cycles, it has been typical to resort to a time-domain electrical simulation tool such as P-Spice or SABER to obtain a time series of the temperature profiles. However, for complex and periodic load cycles, time-series simulation is time consuming. In this paper, a fast Fourier analysis-based approach is presented for obtaining temperature profiles for power semiconductors. …

Mobius: An Omnidirectional Robotic Platform And Software Architecture For Network Teleoperation, Samuel Aaron Miller

Electrical & Computer Engineering Theses & Dissertations

The following thesis presents the results of a project to develop and test an omnidirectional robotic system (hardware and software) at NASA Langley Research Center's Robotics and Intelligent Machines Lab. The impetus for the project was the unique capabilities of omnidirectional systems. Some of the many potential benefits these systems have include improved material-handling capabilities in constrained environments (such as might be found in extraterrestrial manned habitats), efficient camera-based vehicle teleoperation, and simplified route planning for autonomous robot operations.

The project's focus was to design, build, and test a system that used Mecanum wheels to achieve omnidirectional motion. In addition …

Association Of Sound To Motion In Video Using Perceptual Organization, Sunil Babu Ravulapalli

USF Tampa Graduate Theses and Dissertations

Technological developments and innovations of the first forty years of the digital era have primarily addressed either the audio or the visual senses. Consequently, designers have primarily focused on the audio or the visual aspects of design. In the perspective of video surveillance, the data under consideration has always been visual. However, in light of the new behavioral and physiological studies which established a proof of cross modality in human perception i.e. humans do not process audio and visual stimulus separately, but percieve a scene based on all stimulus available, similar cues are being used to develop a surveillance system …

Post Register Allocation Spill Code Optimization, Christopher Lupo, Kent Wilken

Computer Science and Software Engineering

A highly optimized register allocator should provide an efficient placement of save/restore code for procedures that contain calls. This paper presents a new approach to placing callee-saved save and restore instructions that generalizes Chow's shrink-wrapping technique (Chow 1988). An efficient, profile-guided, hierarchical spill code placement algorithm is used to analyze the structure of a procedure to calculate the minimum dynamic execution count locations to place callee-saved save and restore code. The algorithm is implemented in the Gnu Compiler Collection and has been tested on the SPEC CPU2000 Integer Benchmark suite. Results show that the technique reduces the number of dynamic …

Analysis Of Surface Permanent Magnet Machines With Fractional-Slot Concentrated Windings, Ayman M. El-Refaie, Thomas M. Jahns, Donald W. Novotny

Electrical and Computer Engineering Faculty Research and Publications

This paper presents a closed-form analytical technique for analyzing surface PM machines equipped with fractional-slot concentrated windings. Since this class of winding configuration deviates significantly from conventional sinusoidal distributions, classical steady-state phasor or analytical techniques cannot be used to provide accurate results. The presented analytical model provides a fast and reliable method to analyze and compare candidate machine designs. Stator slotting effects are taken into consideration and a wide range of concentrated winding configurations can be analyzed. This technique is capable of analyzing the machine both below (constant-torque) and above (flux-weakening) base speed. Average torque, cogging torque, and ripple torque …

Improved Tool For Fingerspelling Recognition, Rosalee Wolfe, Nora Alba, Stacey Billups, Mary Jo Davidson, Cindy Dwyer, Diana Gorman Jamrozik, Lori Smallwood, Karen Alkoby, Lesley Carhart, Damien Hinkle, Amy Hitt, Brian Kirchman, Glenn Lancaster, John Mcdonald, Lindsay Semler, Jerry Schnepp, Brent Shiver, Anna Suh, Jeffrey Young

Visual Communications and Technology Education Faculty Publications

Conference proceedings from the Technology and Persons with Disabilities Conference-2006. California State University at Northridge, Los Angeles, CA March 20-25, 2006.

Performance Analysis Of Mc-Cdma Communication Systems Over Nakagami-M Environments, Joy Iong-Zong Chen

Journal of Marine Science and Technology–Taiwan

The performance for a MC-CDMA (multi-carrier coded-division multiple-access) system working in uncorrelated and correlated fading channels with Nakagami distribution is investigated in this paper. We adopt the BPSK modulation scheme with an alternative expression for Q-function to evaluate the BER (bit error rate) performance of the MC-CDMA system. The sum of Gamma variates is adopted for deriving a closed-form solution for arbitrarily correlated channel in order to avoid the difficulty of explicitly obtaining the pdf (probability density function) for the SNR (signal-to-noise ratio) at the MRC (maximum ratio combining) output. The results with simple expression obviously show that the BER …

Evaluation Of Energy Costs And Error Performance Of Range-Aware Anchor-Free Localization Algorithms For Wireless Sensor Networks, Gustav Julio Jordt

Theses and Dissertations

This research examines energy and error tradeoffs in Anchor-Free Range-Aware Wireless Sensor Network (WSN) Localization algorithms. A concurrent and an incremental algorithm (Anchor Free Localization (AFL) and Map Growing) are examined under varying network sizes, densities, deployments, and range errors. Despite current expectations, even the most expensive configurations do not expend significant battery life (at most 0.4%), implying little energy can be conserved during localization. Due to refinement, AFL is twice as accurate, using 6 times the communication. For both, node degree affects communication most. As degree increases, Map Growing communication increases, while AFL transmissions drop. Nodes with more neighbors …

3-D Image Registration Using Fast Fourier Transform, With Potential Applications To Geoinformatics And Bioinformaticsa, Roberto Araiza, Matthew G. Averill, George R. Keller, Scott A. Starks

Departmental Technical Reports (CS)

FFT-based techniques are actively used to register 2-D images, i.e., to find the shift, rotation, and scaling necessary to align one image with the other. It is desirable to extend these techniques to the problem of registering 3-D images. Registration of 3-D images is an important problem in areas such as bioinformatics (e.g., in protein docking) and geoinformatics (e.g., in earth modeling).

Computing Variance Under Interval Uncertainty: A New Algorithm And Its Potential Application To Privacy In Statistical Databases, Richard Aló, Mohsen Beheshti, Gang Xiang

Departmental Technical Reports (CS)

Computation of population mean E=(x1+...+xn)/n and population variance V=(x1^2+...+xn^2)/n -E^2 is an important first step in statistical analysis. In many practical situations, we do not know the exact values of the sample quantities xi, we only know the intervals [Xi-Di, Xi+Di] that contain the actual (unknown) values of xi. Different values of xi from these intervals lead, in general, to different value of population variance. It is therefore desirable to compute the range [V]=[V-,V+] of possible values of V.

This problem of computing population variance under interval uncertainty is, in general, NP-hard. It is known that in some reasonable cases, …

Using Expert Knowledge In Solving The Seismic Inverse Problem, Matthew G. Averill, Kate Miller, George R. Keller, Vladik Kreinovich, Roberto Araiza, Scott A. Starks

Departmental Technical Reports (CS)

For many practical applications, it it important to solve the seismic inverse problem, i.e., to measure seismic travel times and reconstruct velocities at different depths from this data. The existing algorithms for solving the seismic inverse problem often take too long and/or produce un-physical results -- because they do not take into account the knowledge of geophysicist experts. In this paper, we analyze how expert knowledge can be used in solving the seismic inverse problem.

Towards Optimal Use Of Multi-Precision Arithmetic: A Remark, Vladik Kreinovich, Siegfried Rump

Departmental Technical Reports (CS)

If standard-precision computations do not lead to the desired accuracy, then it is reasonable to increase precision until we reach this accuracy. What is the optimal way of increasing precision? One possibility is to choose a constant q>1, so that if the precision which requires the time t did not lead to a success, we select the next precision that requires time q*t. It was shown that among such strategies, the optimal (worst-case) overhead is attained when q=2. In this paper, we show that this "time-doubling" strategy is optimal among all possible strategies, not only among the ones in …

Towards Secure Cyberinfrastructure For Sharing Border Information, Ann Q. Gates, Vladik Kreinovich, Luc Longpre, Paulo Pinheiro Da Silva, Randy G. Keller

Departmental Technical Reports (CS)

In many border-related issues ranging from economic collaboration to border security, it is extremely important that bordering countries share information. One reason why such sharing is difficult is that different countries use different information formats and data structures. It is therefore desirable to design infrastructure to facilitate this information sharing.

UTEP is a lead institution in a similar NSF-sponsored multi-million geoinformatics project, whose goal is to combine diverse and complex geophysical and geographical data stored in different formats and data structures. We describe our experience in using and developing related web service techniques, and we explain how this experience can …

Convergence Of Ipsec In Presence Of Resets, Chin-Tser Huang, Mohamed G. Gouda, E.N. Elnozahy

Faculty Publications

IPsec is the current security standard for the Internet Protocol IP. According to this standard, a selected computer pair (p, q) in the Internet can be designated a “security association”. This designation guarantees that all sent IP messages whose original source is computer p and whose ultimate destination is computer q cannot be replayed in the future (by an adversary between p and q) and still be received by computer q as fresh messages from p. This guarantee is provided by adding increasing sequence numbers to all IP messages sent from p to q. Thus, p needs to always remember …

An Adaptable Energy-Efficient Medium Access Control Protocol For Wireless Sensor Networks, Justin T. Kautz

Theses and Dissertations

Wireless networks have become ubiquitous recently and therefore their usefulness has also become more extensive. Wireless sensor networks (WSN) detect environmental information with sensors in remote settings. One problem facing WSNs is the inability to resupply power to these energy-constrained devices due to their remoteness. Therefore to extend a WSN's effectiveness, the lifetime of the network must be increased by making them as energy efficient as possible. An energy efficient medium access control (MAC) can boost a WSN's lifetime. This research creates a MAC protocol called Adaptive sensor Medium Access Control (AMAC) which is based on Sensor Medium Access Control …

Evaluation Of A Field Programmable Gate Array Circuit Reconfiguration System, Jason L. Ives

Theses and Dissertations

This research implements a circuit reconfiguration system (CRS) to reconfigure a field programmable gate array (FPGA) in response to a faulty configurable logic block (CLB). It is assumed that the location of the fault is known and the CLB is moved according to one of four replacement methods: column left, column right, row up, and row down. Partial reconfiguration of the FPGA is done through the Joint Test Action Group (JTAG) port to produce the desired logic block movement. The time required to accomplish the reconfiguration is measured for each method in both clear and congested areas of the FPGA. …

Supplementing An Ad-Hoc Wireless Network Routing Protocol With Radio Frequency Identification (Rfid) Tags, Leroy S. Willemsen

Theses and Dissertations

Wireless sensor networks (WSNs) have a broad and varied range of applications, yet all of these are limited by the resources available to the sensor nodes that make up the WSN. The most significant resource is energy. A WSN may be deployed to an inhospitable or unreachable area, leaving it with a non-replenishable power source. This research examines a way of reducing energy consumption by augmenting the nodes with radio frequency identification (RFID) tags that contain routing information. It was expected that RFID tags would reduce the network throughput, the ad hoc on-demand distance vector (AODV) routing traffic sent, and …

Power-Scavenging Mems Robots, Daniel J. Denninghoff

Theses and Dissertations

This thesis includes the design, modeling, and testing of novel, power-scavenging, biologically inspired MEMS microrobots. Over one hundred 500-μm and 990-μm microrobots with two, four, and eight wings were designed, fabricated, characterized. These microrobots constitute the smallest documented attempt at powered flight. Each microrobot wing is comprised of downward-deflecting, laser-powered thermal actuators made of gold and polysilicon; the microrobots were fabricated in PolyMUMPs® (Polysilicon Multi-User MEMS Processes). Characterization results of the microrobots illustrate how wing-tip deflection can be maximized by optimizing the gold-topolysilicon ratio as well as the dimensions of the actuator-wings. From these results, an optimum actuator-wing configuration was …

Characterization And Design Of High-Level Vhdl I/Q Frequency Downconverter Via Special Sampling Scheme, Jesse P. Somann

Theses and Dissertations

This study explores the characterization and implementation of a Special Sampling Scheme (SSS) for In-Phase and Quad-Phase (I/Q) down conversion utilizing top-level, portable design strategies. The SSS is an under-developed signal sampling methodology that can be used with military and industry receiver systems, specifically, United States Air Force (USAF) video receiver systems. The SSS processes a digital input signal-stream sampled at a specified sampling frequency, and down converts it into In-Phase (I) and Quad-Phase (Q) output signal-streams. Using the theory and application of the SSS, there are three main objectives that will be accomplished: characterization of the effects of input, …

Optimal Coverage Of Theater Targets With Small Satellite Constellations, Axel Rendon

Theses and Dissertations

The daylight passes of a low-Earth orbit satellite over a targeted latitude and longitude are optimized by varying the inclination and eccentricity of an orbit at different altitudes. This investigation extends the work by Emery et al, in which the optimal Right Ascension of the Ascending Node was determined for a circular, matched inclination orbit. The optimal values were determined by a numerical research method based on Emery et al's Matlab program. Results indicate that small increases in inclination raise the number of daylight passes up to 33%. These optimal inclinations depend on the satellite semi-major axis. Eccentricity increases also …

Threading And Autodocumenting News Videos: A Promising Solution To Rapidly Browse News Topics, Xiao Wu, Chong-Wah Ngo, Qing Li

Research Collection School Of Computing and Information Systems

This paper describes the techniques in threading and autodocumenting news stories according to topic themes. Initially, we perform story clustering by exploiting the duality between stories and textual-visual concepts through a co-clustering algorithm. The dependency among stories of a topic is tracked by exploring the textual-visual novelty and redundancy of stories. A novel topic structure that chains the dependencies of stories is then presented to facilitate the fast navigation of the news topic. By pruning the peripheral and redundant news stories in the topic structure, a main thread is extracted for autodocumentary

Splash: Systematic Proteomics Laboratory Analysis And Storage Hub, Siaw Ling Lo, You Tao, Qingsong Lin, Shashikant B. Joshi, Maxey Chung, Choy Leong Hew

Research Collection School Of Computing and Information Systems

In the field of proteomics, the increasing difficulty to unify the data format, due to the different platforms/instrumentation and laboratory documentation systems, greatly hinders experimental data verification, exchange, and comparison. Therefore, it is essential to establish standard formats for every necessary aspect of proteomics data. One of the recently published data models is the proteomics experiment data repository [Taylor, C. F., Paton, N. W., Garwood, K. L., Kirby, P. D. et al., Nat. Biotechnol. 2003, 21, 247-254]. Compliant with this format, we developed the systematic proteomics laboratory analysis and storage hub (SPLASH) database system as an informatics infrastructure to support …