Engineering Commons^™

An Evaluation Of Public Construction Contracting Methods For The Public Building Sector In Oregon Using Data Envelopment Analysis, Gerald Herman Williams Jr.

Dissertations and Theses

Since 1976 public agencies in Oregon have been allowed to select construction contractors using a "qualification" based competition instead of the more typical lowest responsible bid or Design-Bid-Build (DBB) basis. Since 1985, at least 136 such selections, commonly known as CM/GC for Construction Manager/General Contractor, have been made. The results of this policy have not previously been analyzed. This research compares these selection methods, seeking to answer the following questions:

1. Does the CMl/GC method result in projects that differ from DBB projects regarding cost and schedule control?

2. Are CMl/GC projects more efficient than DBB projects, where efficiency is defined as …

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Line Detection Using Wavelet Filters, Somkait Udomhunsakul, Samuel Peter Kozaitis, Uthai Thai Sritheeravirojana, A. Khempila

Electrical Engineering and Computer Science Faculty Publications

We proposed a new line detection method in noisy images using Mexican hat wavelet filters. In our approach, we applied the wavelet transform in a multiresolution sense by forming the products of wavelet coefficients at the different scales to locate and identify lines at different scales. In addition, we also considered shifting line locations through multiple scales for robust line detection in the presence of noise. We found that our approach leads to an effective method to form the basis of a line detection approach.

Task 32 Delayed Hydride Cracking Of Spent Fuel Cladding Under Repository Conditions, Ajit K. Roy, Anthony Hechanova, Amy J. Smiecinski

Publications (YM)

The objective of this quality-affecting task is to evaluate the susceptibility of spent nuclear fuel cladding materials (zirconium alloys) to stress corrosion cracking (SCC), delayed hydride cracking (DHC) and localized corrosion (pitting/crevice) in simulated repository environments. During the first year of this project, major efforts were focused on developing the infrastructure for performing the desired testing involving two highly corrosion-resistant alloys namely, zircaloy-2 (Zr-2) and zircaloy-4 (Zr-4) in simulated concentrated acidic water (SAW) and modified SAW (SAWM). Modification of the SAW chemistry was done by adding hydrochloric acid (HC1) to achieve lower pH. The construction of the "Materials Performance Laboratory …

Thermal Transport Eveluations Related To Waste Package Design -- Model Evaluations -- Task 19, Roald Akberov

Publications (YM)

The purpose of the “Thermal Transport Evaluations Related to Waste Package Design” Task # 19 of Cooperative Agreement Number DE-FC28-98NV12081 was to develop a new CFDHT model for heat transfer and fluid flow in the potential rsepository at the Yucca Mountain, Nevada and to study the effects of forced convection during the pre-closure period and natural convection during the postclosure period. The analysis was performed for the drift dimensions shown in Figure 4-1 below. The intended use of the model is to estimate the velocity and temperature distribution as well as the highest temperature in the drift during the pre-closure …

Commentary On Philosophy And Aviation Security, Ibpp Editor

International Bulletin of Political Psychology

This article outlines how the formal study of philosophy can be applied to aviation security, considering the merits of the inclusion of philosophers in the international working groups tasked with discerning and commenting on aviation security trends and their relevance for intelligence and security activities.

A Five-Zone Model For Direct Injection Diesel Combustion, Rich Asay

Theses and Dissertations

Recent imaging studies have provided a new conceptual model of the internal structure of direct injection diesel fuel jets as well as empirical correlations predicting jet development and structure. This information was used to create a diesel cycle simulation model using C language including compression, fuel injection and combustion, and expansion processes. Empirical relationships were used to create a new mixing-limited zero-dimensional model of the diesel combustion process. During fuel injection five zones were created to model the reacting fuel jet: 1) liquid phase fuel 2) vapor phase fuel 3) rich premixed products 4) diffusion flame sheath 5) surrounding bulk …

Theory, Design, And Fabrication Of Diffractive Grating Coupler For Slab Waveguide, Kevin Randolph Harper

Theses and Dissertations

This thesis presents the theory design and fabrication of a diffractive grating coupler. The first part of the design process is to choose the period of the grating coupler based on the desired coupling angle. The second part of the design process is to choose the geometry of the grating that gives maximum coupling efficiency based on rigorous analyses.

The diffraction gratings are fabricated by recording the interference between two waves in photoresist. The waveguide is fabricated from silicon nitride that is deposited by chemical vapor deposition. The diffraction grating recording assembly is described along with the grating coupler fabrication …

A Descriptive Performance Model Of Small, Low Cost, Diskless Beowulf Clusters, Curtis R. Nielson

Theses and Dissertations

Commodity supercomputing clusters known as Beowulf clusters, have become a low cost alternative to traditional supercomputers. Beowulf clusters combine inexpensive computers and specialized software to achieve supercomputing power. The processing nodes in a diskless Beowulf cluster do not have a local hard disk unlike the nodes in most commodity clusters. Research has provided performance information for diskless clusters built with expensive, high performance equipment. Beowulf clusters use commodity off-the-shell hardware, and little information is available about their performance. This research includes the construction of several diskless Beowulf clusters. Using the NAS Parallel Benchmarks, the performance of these clusters was measured. …

A Simplified Approach To Estimate The Ultimate Longitudinal Strength Of Ship Hull, Hsin-Chuan Kuo, Jiang-Ren Chang

Journal of Marine Science and Technology–Taiwan

In this paper, the calculation of the ultimate longitudinal strength of the ship hull is revisited. A simplified approach dealing with the longitudinal ultimate strength of ship hull has been developed and an effective numerical program is implemented based on the individual components of ship structures. It is, then, possible to find the ultimate strength of the whole ship structure by evaluating those individual components. Comparisons of numerical results from the proposed approach and published literatures are conducted for further validation. Since relative errors of calculations of the current approach to the literature with respect to the experimental data are …

An Analytical Model For Deflection Of Laterally Loaded Piles, Jen-Cheng Liao, San-Shyan Lin

Journal of Marine Science and Technology–Taiwan

Load-deflection responses of laterally loaded piles are often obtained via in-situ lateral pile load tests. Problems of such tests are the difficulties occurring during data interpretation. In an effort to develop an efficient analytical method for analyzing deformation data of lateral loaded piles, an analytical model is proposed based on energy conservation of pile-soil system. The proposed analytical model not only provides a direct solution of the pile deflection function, but also has less need of complicated subsurface soil properties. In this paper, the authors present the theory and analytical model development of the proposed method. Two real cases are …

Model-Based Fuzzy Modeling And Control For Autonomous Underwater Vehicles In The Horizontal Plane, Wen-Jer Chang, Wei Chang, Hsien-Hsueh Liu

Journal of Marine Science and Technology–Taiwan

In this paper, the modeling and control of nonlinear Autonomous Underwater Vehicle (AUV) system is considered by using a TakagiSugeno (T − S) type fuzzy model. Applying the AUV T − S fuzzy model, one can develop a model-based fuzzy controller design utilizing the concept of Parallel Distributed Compensation (PDC). The main idea of the controller design approach is to derive each control rule so as to compensate each rule of a fuzzy system. The design procedure is conceptually simple and natural. Finally, the responses of states of AUV dynamic real system and AUV dynamic T − S fuzzy model …

A Practical Experience About Dynamic Performance And Stability Improvement Of Synchronous Generators, Chi-Jui Wu, Yung-Sung Chuang

Journal of Marine Science and Technology–Taiwan

This paper describes the practical experiences about the no-load dynamic performance test, parameter identification, and tuning of static excitation systems (SESs) of the synchronous generators in the Tong-Shiao Generation Station of the Taiwan Power System. The dynamic stability of under-load generators has also been improved. The hardware circuits of SESs had been modified. This caused the detuning of parameter values, so that the generators did not have enough ability to sustain voltage fluctuation disturbances. Several SESs had been preliminarily retuned according to the results from simple field tests. However, step signal responses in field tests revealed that the characteristics of …

Experimental Study Of The Rheological Behaviors Of Fresh Concrete, Mortar, And Clay Grout, Cho-Liang Tsai, Yun Du, Yi-Shiun Tsai

Journal of Marine Science and Technology–Taiwan

Most studies assume that fresh concrete is a Bingham fluid, but few studies precisely measure its Bingham constants, shear yield stress and viscosity, especially for normal fresh concrete. In stead of using commercial viscometer, this work developed a new experimental method and analytical procedure, based on the Stokes’ flow, for characterizing rheological properties of fluids. The experimental method developed here involved dragging a sphere submerged in the specimen fluid at a constant speed and measuring the resistance. Rheological properties of the specimen fluid can be calculated from the theoretical function correlating the drag velocity, drag force, and rheological properties of …

Magneto-Hydrodynamic Squeeze Film Characteristics Between A Sphere And A Plane Surface, Tsu-Liang Chou, Jen-Wen Lai, Jaw-Ren Lin

Journal of Marine Science and Technology–Taiwan

Based upon the thin-film magneto-hydrodynamic (MHD) theory, this paper analyzes the squeeze-film characteristics between a sphere and plane surface lubricated with an electrically conducting fluid in the presence of a transverse magnetic field. The MHD Reynolds-type equation governing the squeeze-film pressure is derived using the continuity equation and the magneto-hydrodynamic motion equations. A closed-form solution for the squeezing film pressure is obtained, and applied to predict the MHD squeeze-film characteristics. According to the results obtained, the presence of externally applied magnetic fields signifies an enhancement in the squeeze-film pressure. On the whole, the magnetic-field effects characterized by the Hartmann number …

Sufficient Conditions For Admittance To Ensure Planar Force-Assembly In Multi-Point Frictionless Contact, Shuguang Huang, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

An important issue in the development of force guidance assembly strategies is the specification of an appropriate admittance control law. This paper identifies procedures for selecting the appropriate admittance to achieve reliable planar force-guided assembly for multi-point contact cases. Conditions that restrict the admittance behavior for each of the various types of two-point contact are presented. These conditions ensure that the motion that results from contact reduces part misalignment for each case. We show that, for bounded misalignments, if the conditions are satisfied for a finite number of contact configurations, the conditions ensure that force guidance is achieved for all …

Admittance Selection For Planar Force-Guided Assembly For Single-Point Contact With Friction, Shuguang Huang, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

This paper identifies procedures for selecting the appropriate admittance to achieve reliable planar force-guided assembly for single-point frictional contact cases. A set of conditions that are imposed on the admittance matrix is presented. These conditions ensure that the motion that results from contact reduces part misalignment. We show that, for bounded misalignments, if an admittance satisfies the misalignment-reduction conditions at a finite number of contact configurations and a given coefficient of friction /spl mu//sub M/) then the admittance will also ensure that the conditions are satisfied at all intermediate configurations for all coefficients less than /spl mu//sub M/.

Efficient Contact State Graph Generation For Assembly Applications, Feng Pan, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

An important aspect in the design of many automated assembly strategies is the ability to automatically generate the set of contact states that may occur during an assembly task. In this paper, we present an efficient means of constructing the set of all geometrically feasible contact states that may occur within a bounded set of misalignments (bounds determined by robot inaccuracy). This set is stored as a graph, referred to as an Assembly Contact State Graph (ACSG), which indicates neighbor relationships between feasible states. An ACSG is constructed without user intervention in two stages. In the first stage, all hypothetical …

Study Guide For Photovoltaic System Installers And Sample Examination Questions, Florida Solar Energy Center, James Dunlop

FSEC Energy Research Center®

This Study Guide presents some of the basic cognitive material that individuals who install and maintain photovoltaic (PV) power systems should know and understand. This information is intended primarily as a Study Guide to help individuals better prepare for the NABCEP PV installer examination but does not provide all of the materials needed for completing the certification examination. Knowledge of the information presented, knowledge of pertinent sections of the National Electrical Code and appropriate experience and qualifications, are generally required of those applying for and completing the NABCEP certification process. Applicants and certificants are also reminded that local installation codes …

Underground Pipe Locating Demonstration At Arvin-Edison Water Storage District, Stuart Styles

BioResource and Agricultural Engineering

A presentation/demonstration of some of the latest underground pipe locating equipment was conducted on August 13, 2003 at the Arvin-Edison Water Storage District. All the techniques shown were non-destructive pipe locating procedures that provide approximations to the depth and location of underground-buried pipe.

3 types of technology were shown at the demonstration:

1. Acoustic pipe locators
2. Leak detectors
3. Ground penetrating radar

Each form of technology has its own merits and advantages. Acoustic technology is effective in locating single, small diameter pipes with pressurized flow located within about 500-ft of the sound (sonde) units. Leak detection technology is more accurate in locating …

A Concept For Early Cancer Detection And Therapy, Ronald W. Waynant, Ilko K. Ilev, Kunal Mitra

Biomedical Engineering and Sciences Faculty Publications

Early detection and treatment of breast cancer is least costly in terms of dollars, morbidity and mortality. With new early detection x-ray technology, tumors can be found, diagnosed and treated at a much smaller size than is currently possible. This paper proposes the development of a high resolution, high quality imaging system. It is a laser-driven x-ray system with time-gated detection that removes scattering noise in the image and produces resolution on the order of 10 μm. This higher resolution and higher image quality will enable the detection of one or two millimeter tumors hopefully detecting them before metastasis. We …

Reduction Of Multiplicative Noise Using Higher-Order Statistics, Samuel Peter Kozaitis, Anurat Ingun, Rufus H. Cofer

Electrical Engineering and Computer Science Faculty Publications

We used a higher-order correlation-based method for signal denoising of images corrupted by multiplicative noise. Using the logarithm of an image, we applied a third-order correlation technique for identification of wavelet coefficients that contained mostly signal. In our approach, we examined wavelet coefficients in an environment where the contribution from the second-order moment of the noise had been reduced. Our results compared favorably and were less sensitive to threshold selection when compared to a second-order wavelet denoising method.

Evaluating Tmr Techniques In The Presence Of Single Event Upsets, Paul S. Graham, Nathaniel Rollins, Michael J. Wirthlin, Michael P. Caffrey

Faculty Publications

Sponsorship: Los Alamos National Labs (LA-UR-03-7525). Field programmable gate arrays (FPGAs) are sensitive to radiation-induced single event upsets (SEUs) within the configuration memory. Triple modular redundancy (TMR) is a technique commonly used to mitigate against design failures caused by SEUs. This paper evaluates the effectiveness and cost of TMR on two different counter designs in the presence of SEUs. The evaluation measures the reliability, area cost, and speed of different TMR styles. The tests show that when feedback TMR is used with triplicated clocks, it is possible to have counter design which is insensitive to any single configuration upset.

Deterministic Surface Registration At 10hz Based On Landmark Graphs With Prediction, Fred W. Depiero

Electrical Engineering

Landmark graphs provide a means for surface registration, based on determining subgraph isomorphism to find scene-to-scene correspondences. Surface data used herein included both range and colour imagery. Images were acquired of a static scene from a moving sensor. The continuous motion allowed the sensor position to be predicted, which helped stabilize graph formation. Landmarks were determined using the KLT corner detector. Graph structure was established using nodes (landmarks) and edges that agreed well with predicted locations. Subgraph matching was approximated using the LeRP algorithm. A 6 DOF rigid transformation including translation and rotation was found via Horn’s method. Test results …

Plasticized, Antiplasticized And Crystalline Conducting Polymers And Precursors Thereof, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

Materials containing precursors to electrically conductive polymers and electrically conductive polymers are described which have a high degree of crystallinity. The high degree of crystallinity is achieved by preparing the materials under conditions which provide a high degree of mobility to the polymer molecules permitting them to associate with one another to form a crystalline state. High levels of electrical conductivity are achieved in the electrically conductive materials without stretch orienting the material. The enhanced electrical conductivity is isotropic as compared to a stretch oriental film which has isotropic electrical conductivity.

Surface Registration At 10hz Based On Landmark-Graphs: Benefits For A Scalable Remote Viewing System, Fred W. Depiero

Electrical Engineering

Real-time surface registration is a key technology for the development of future remote viewing systems. An architecture for a video distribution system supporting multiple users, with individual viewpoint selection, is suggested. The approach would provide a transmission bandwidth independent of the number of users, for scalability. The proposed architecture uses a method of surface registration based on landmark-graphs. Results from 141 test trials on synthetic scenes indicate that a mean absolute positioning accuracy under 1% of the sensor field of view is possible. The mean rate for registration was 10Hz, with a standard deviation under 10%. Tests were benchmarked on …

On Friction And Surface Cracking During Sliding Of Ice On Ice, Maurine Montagnat, Erland M. Schulson

Dartmouth Scholarship

As a complement to earlier measurements on the friction of both granular fresh-water ice and S2 columnar salt-water ice, new experiments were performed on the friction of S2 columnar fresh-water ice sliding against itself at low velocities (5 × 10−7 to 5 × 10−1 m s−1) and at −10°C, using the same double-shear device as was used earlier. The results showed that under a given set of experimental conditions the kinetic coefficient of friction of S2 fresh-water ice compares favorably with that of the other two variants.The experiments also revealed friction-induced surface cracks and recrystallized grains.These deformation features are explained, …

Effect Of Different Supplementary Cementitious Material On The Microstructure And Its Resistance Against Chloride Penetration Of Concrete, Vinay S. Nikam , Vikram Y. Tambvekar

Advanced Materials for Construction of Bridges, Buildings, and Other Structures III

Various research programes on long term durability of concrete are going on through -out the world. An attempt is made to study the microstructure of the concrete with the addition of different SCM like fly ash, GGBS, metakaolin, silica fume, and rice husk ash. In this paper, data is presented in a simplified manner for the sake of convenience. Hydration is a continuous process and so microstructure of HPC and interfacial zone (ITZ) can change with age and effect of environment by the influencing agents present in it.

Rapid chloride permeability test (RCPT) is carried out on the various samples …

Design Of A Pultruded Gfrp Deck For Highway Bridges, Hyeong-Yeol Kim, Sun-Myung Kim, Yoon-Koog Hwang

Advanced Materials for Construction of Bridges, Buildings, and Other Structures III

This paper deals with the design and analysis of a GFRP deck for the highway bridges. Several cellular tube sections are assessed to obtain a viable cross-sectional profile of the deck. Two GFRP patterns are proposed and tested. Using the proposed deck profile and GFRP patterns, a GFRP deck for a prototype steel I-girder bridge is designed and presented in this paper.

Development Of Space Truss Structure Using Glass Fiber Reinforced Plastics, Hiroya Hagio, Yoshikazu Utsumi, Kohzo Kimura, Koichiro Takahashi, Go Itohiya, Hitoshi Tazawa

Advanced Materials for Construction of Bridges, Buildings, and Other Structures III

This paper describes the development of a space truss structure using Glass Fiber Reinforced Plastic (GFRP) pipe that decreases life cycle cost and enhances construction efficiency. Material tests, structural experiments and FEM analysis verify the practicality of this structural system.

Reliability Analysis On Flexural Behavior Of Frp Bridge Decks, Sang-Mo Jeong, Sang-Jin Kim, Young-Bum Kim, Hyeong-Yeol Kim, Ki-Tae Park

Advanced Materials for Construction of Bridges, Buildings, and Other Structures III

Design codes for the design of FRP bridge decks shall be established to promote the use of such innovative materials. For the purpose of preparing code provisions, reliability analyses were conducted to evaluate proper levels of safety and serviceability. Based on the results, several guidelines on design codes are suggested.