DigitalCommons@CalPoly Copyright (c) 2012 California Polytechnic State University All rights reserved. http://digitalcommons.calpoly.edu Recent documents in DigitalCommons@CalPoly en-us Mon, 13 Feb 2012 02:51:34 PST 3600 DETERMINATION OF THE MODAL PARAMETERS OF A FIVE STORY REINFORCED CONCRETE STRUCTURE USING ULTRA-LOW LEVEL EXCITATION AND COMPUTATIONAL ANALYSIS http://digitalcommons.calpoly.edu/theses/687 http://digitalcommons.calpoly.edu/theses/687 Fri, 10 Feb 2012 15:16:30 PST The determination of a building’s modal parameters (natural periods and mode shapes) using ultra-low level forced vibration testing and analytical modeling were critically compared. The structure utilized for this experiment is the Robert E. Kennedy Library on the campus of California Polytechnic State University San Luis Obispo, a five-story reinforced concrete shear wall structure. The specific testing procedure used has been verified to produce accurate results in smaller buildings, but the Kennedy Library represents the most massive subject structure. Other characteristics of this structure that make it unique include a large atrium at the center of the building and modes that are closely spaced in the frequency domain. Comparing the results from the computational models and the experimental analysis showed that the computational models underestimated the building periods by approximately 6-12%. This discrepancy in the results was attributed to an underestimation of the building mass, possible soil-structure interaction, and likely cracking of the concrete slab and shear walls. Modeling of the shear walls as both line elements and area elements was also explored and the consequences of each were determined.

]]> Adam Russell Rendon Polar Field Oriented Control with 3rd Harmonic Injection http://digitalcommons.calpoly.edu/theses/686 http://digitalcommons.calpoly.edu/theses/686 Wed, 08 Feb 2012 11:50:57 PST Abstract

POLAR FIELD-ORIENTED CONTROL

with

3RD HARMONIC INJECTION

Martin Todd Hess

Field Oriented Control (FOC), also known as vector control, is a widely used and well documented method for controlling Permanent-Magnet Synchronous Motors (PMSM) and induction motors. Almost invariably the orientation of the stator and rotor (field) fluxes are described in rectangular coordinates. In this thesis we explore the practicality of using polar coordinates.

Third harmonic injection is also a well-known technique that allows full utilization of the bus (DC-link), thus allowing the motor to run to full base speed without the use of field weakening. This technique potentially allows a 15.4% improvement in the available bus. It has fallen out of use since it requires direct knowledge of the terminal voltage vector angle. The use of polar FOC permits the use of third-harmonic injection.

We believe the combination of FOC and third-harmonic injection to be unique, and we present this paper as a novel contribution to the literature on the subject of motor control.

]]> Martin Todd Hess Structural Design Practice Assumptions and Code Interpretation http://digitalcommons.calpoly.edu/aen_fac/65 http://digitalcommons.calpoly.edu/aen_fac/65 Wed, 08 Feb 2012 08:51:57 PST Craig Baltimore Project Managers, Architects, and Engineers--Oh my! An Interdisciplinary Collaboration http://digitalcommons.calpoly.edu/aen_fac/64 http://digitalcommons.calpoly.edu/aen_fac/64 Wed, 08 Feb 2012 08:51:53 PST The Architectural Engineering (ARCE) Program at the California Polytechnic State University in San Luis Obispo is creating a unique and novel interdisciplinary course where architecture, architectural engineering and construction management students collaborate to design and plan the construction of a building structure. The current plan is to develop a default interdisciplinary experience that can be taken by every student and then allow course substitutions for other options as they are created. This paper reports on one of those other options, specifically a unique real world, global, multi-disciplinary experience in East Africa that has resulted from a master’s degree project that incorporated 14 undergraduates into the work. The project is entering its second year, now includes 24 undergraduate students and has the potential to continue well into the future. The students are supporting the Catholic diocese in Same, Tanzania to design a polytechnic school to accommodate up to 500 students. The design experience is allowing students to address the social, political, economic, constructability, and global issues that come from a real world project on a different continent. The students are incorporating local labor capabilities, regional material availability, climate, seismic vulnerabilities, and local customs and traditions into their design. To minimize the costs of construction, operation and maintenance, the student design includes efficient construction methods, energy sustainability and water sustainability.

]]> David Lambert et al. Going Green with Concrete Masonry Grout http://digitalcommons.calpoly.edu/aen_fac/63 http://digitalcommons.calpoly.edu/aen_fac/63 Wed, 08 Feb 2012 08:51:50 PST Concrete, which is a product containing Portland cement, is the second most used building material (after water) worldwide. Masonry grout is similar to concrete except that grout has a high water content and smaller size aggregates. The excess water is immediately absorbed into the masonry units during placement, which lowers the water/cement ratio and allows for a normal hydration process. During the process of making Portland cement, more than 1/5 ton of carbon dioxide is produced for every ton of cement with 60% of the carbon dioxide production due to a chemical reaction. There is currently no viable remedy to reduce the carbon dioxide emission due to this chemical process. To limit carbon dioxide emission from Portland cement production, cement use in concrete products can be reduced (e.g. concrete and grout) [1]. However, the reduction in Portland cement content must not compromise strength or building processes (time).

]]> James Mwangi et al. Season and Sex of Host Affect Intensities of Ectoparasites in Western Fence Lizards <em>(Sceloporus Occidentalis)</em> on the Central Coast of California http://digitalcommons.calpoly.edu/bio_fac/385 http://digitalcommons.calpoly.edu/bio_fac/385 Tue, 07 Feb 2012 17:14:31 PST Seasonal variability in intensities of ectoparasites of western fence lizards (Sceloporus occidentalis) was quantified in spring, summer, and autumn 2008. Lizards were suspended over pans of water in the laboratory to enumerate replete western black-legged ticks (Ixodes pacificus) and mites. Intensity of ectoparasites was greatest in spring. On average, mites comprised the greatest proportion of ectoparasites, followed by larval and nymphal ticks, respectively. Mites were on lizards year-round. Overall intensity of ticks was greatest in spring, but low during summer and autumn. Males were more heavily parasitized by ticks than females in spring, whereas females had greater intensities of mites in autumn. There was a slight, positive relationship between size of lizard and intensity of ticks, but not with intensity of mites. We report greater intensities of ectoparasites on S. occidentalis than several other studies, which may be due to differences in habitats and methods.

]]> Anthony S. Lumbad et al. <sup>130</sup>Te neutrinoless double-beta decay with CUORICINO http://digitalcommons.calpoly.edu/phy_fac/361 http://digitalcommons.calpoly.edu/phy_fac/361 Tue, 07 Feb 2012 16:59:22 PST We report the final result of the CUORICINO experiment. Operated between 2003 and 2008, with a total exposure of 19.75 kg · y of 130Te, CUORICINO was able to set a lower bound on the 130Te 0vββ half-life of 2.8 x 1024 years at 90% C.L. The limit here reported includes the effects of systematic uncertainties that are examined in detail in the paper. The corresponding upper bound on the neutrino Majorana mass is in the range 300–710 meV, depending on the adopted nuclear matrix element evaluation.

]]> E. Andreotti et al. Development of Wind Tunnel for Laboratory Wind Turbine Testing http://digitalcommons.calpoly.edu/eeng_fac/290 http://digitalcommons.calpoly.edu/eeng_fac/290 Tue, 07 Feb 2012 16:42:04 PST This paper presents the development of a wind tunnel that will be used for wind turbine testing in a controlled environment. The prototype is designed to be able to provide wind speeds of up to 20 m/s (~43mph) depending on the cross sectional area of the tunnel chamber. A 42 inch tube axial fan is driven by a 5hp induction motor using a variable frequency drive to allow continuously variable wind speeds from near zero up to the maximum wind speed. The fan is rated to produce ~25,000 CFM and the corresponding wind speed is therefore dependent on chamber cross sectional area. There will be two chamber sizes possible. One is 2.5 feet by 2.5 feet and the other is 3.25 feet by 3.25 feet. The larger cross section allows larger turbines to be tested while the smaller cross section allows higher wind speeds to be reached. The paper also describes some possible applications of the apparatus in the academic environment.

]]> Dale S. Dolan et al. A New Undergraduate Laboratory Course in Magnetic Design http://digitalcommons.calpoly.edu/eeng_fac/289 http://digitalcommons.calpoly.edu/eeng_fac/289 Tue, 07 Feb 2012 16:41:51 PST This paper presents a set of new laboratory experiments developed in conjunction with an undergraduate course in magnetic design. The course has recently been reintroduced as a technical elective course where students learn the basics of inductor and transformer design. Five new laboratory experiments have been developed to cover magnetic concepts and to provide students with the hands-on experience in designing and building magnetic components. The paper presents an overview of the course, and highlights the new lab experiments in the course.

]]> Taufik Taufik et al. A Parallel Energy-Sharing Control for Fuel Cell-Battery- Ultracapacitor Hybrid Vehicle http://digitalcommons.calpoly.edu/eeng_fac/288 http://digitalcommons.calpoly.edu/eeng_fac/288 Tue, 07 Feb 2012 16:41:39 PST This paper proposes a parallel energy-sharing control for fuel cell hybrid vehicles (FCHVs) application. The hybrid source consists of fuel cells (FCs) stack, battery packs and Ultracapacitor (UC) modules. In the proposed parallel energy sharing control, each source is connected to a DC bus via power electronics converters. A total of six control loops are applied in the supervisory system in order to regulate the DC bus voltage, control of power flow and at the same time to monitor the state of charge (SOC) of each energy storage device. Simulation with experiment verifications are carried out to verify the proposed energy control system.

]]> JennHwa Wong et al. MONETARY FACTORS and the U.S. RETAIL FOOD PRICE LEVEL http://digitalcommons.calpoly.edu/theses/685 http://digitalcommons.calpoly.edu/theses/685 Tue, 07 Feb 2012 10:58:39 PST The following study assesses whether an economic relationship exists between the money supply (i.e. M2), interest rates, and the exchange rate and the retail food price level in the United States. Data for the M2 classification of the United States money supply, the Effective Federals Funds (interest) Rate, and the United States Trade Weighted Exchange Index: Major Currencies for the period from January 1974 through December 2007 are evaluated as they relate to the United States Consumer Price Index for all Urban Consumers: Food for the same period. The statistical analysis involves an examination of the autocorrelation and partial autocorrelation functions of each variable, a test for the presence of stationarity in each variable(Augmented Dickey-Fuller test), Johansen’s test for co-integrating equations of the variables considered, Granger’s test for causality, and finally an estimation of regression models of United States retail food prices as a function of the money supply, interest rates, and exchange rates.

Results indicate that a statistically significant relationship exists among the variables tested. A causal relationship exists between the Federal Funds Rate and the money supply, the money supply and the retail level of food prices, and also between the exchange rate and the retail level of food prices. The implications of the results are assessed through the lens of agricultural producers and processors, investors, lenders, consumers, and monetary and agricultural policymakers.

Keywords: retail food prices, money supply, Federal Funds Rate, exchange rate, augmented Dickey-Fuller, Johansen’s test for co-integration, Granger causality

]]> Andrew L. Pulford Finite-state Markov Chains Obey Benford’s Law http://digitalcommons.calpoly.edu/rgp_rsr/82 http://digitalcommons.calpoly.edu/rgp_rsr/82 Tue, 07 Feb 2012 08:42:21 PST A sequence of real numbers(xn)is Benford if the significands, i.e. the fraction parts in the floating-point representation of (xn), are distributed logarithmically. Similarly, a discrete-time irreducible and aperiodic finite-state Markov chain with probability transition matrix P and limiting matrix P* is Benford if every component of both sequences of matrices (Pn −P*)and (P n+1-Pn) is Benford or eventually zero. Using recent tools that established Benford behavior both for Newton’s method and for finite-dimensional linear maps, via the classical theories of uniform distribution modulo 1 and Perron-Frobenius, this paper derives a simple sufficient condition (“nonresonance”) guaranteeing that P, or the Markov chain associated with it, is Benford. This result in turn is used to show that almost all Markov chains are Benford, in the sense that if the transition probabilities are chosen independently and continuously, then the resulting Markov chain is Benford with probability one. Concrete examples illustrate the various cases that arise, and the theory is complemented with several simulations and potential applications.

]]> Arno Berger et al. Downtown Revitalization Strategy Report for Glenrock, WY http://digitalcommons.calpoly.edu/theses/684 http://digitalcommons.calpoly.edu/theses/684 Mon, 06 Feb 2012 09:41:36 PST ABSTRACT

Downtown Revitalization Strategy Report for Glenrock, WY

Mary E. Phillips

The following project submitted for the Master of City and Regional Planning Professional Project is the Downtown Revitalization Strategy Report for Glenrock, WY completed November 25, 2009.

At the onset of the project, the Town of Glenrock, WY was recognized as an Aspiring Main Street Community, and sought guidance to become a Certified Main Street Community. This Strategy Report was prepared to provide an implementation plan for revitalization of the downtown following the Main Street Approach, as well as for achievement of a Certified Main Street Community status by the year 2014.

The project included an interactive process, directly involving key representatives and stakeholders in the community. This included a public workshop and on-site strategy sessions with Town staff and the Glenrock Downtown Development Committee. The Strategy Report includes a basic assessment of existing conditions in downtown Glenrock based on information gathered at these meetings. From this initial assessment, issues, goals and objectives for downtown were identified. An overall strategy was then developed, in accordance with the Main Street Approach, which outlines the plan of action for the downtown revitalization and Main Street certification.

The implementation section of the plan then takes the identified actions and prioritizes them based on a 5-year implementation schedule. The development and prioritization of these actions was based on the following factors:

  • Requirements for the Wyoming Main Street Community certification status
  • Community goals for development in the downtown
  • Feasibility of implementation of plan components
  • Access to resources (of all types) for implementation
  • Players in the implementation of the plan

The result of this methodology was a plan that addressed the community’s needs, with an implementation program specifically tailored for the community’s available resources.

]]> Mary Phillips