3,870 research outputs found

    Multidisciplinary Game-Based Approach for Generating Student Enthusiasm for Addressing Critical Infrastructure Challenges

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    Building upon experiences from past course offering,1 several universities across the United States (U.S) have incorporated a critical infrastructure educational game platform as a unifying platform to integrate different disciplines to a common goal. The critical infrastructure backbones of the world provide the delivery mechanisms for energy and other utilities that provide the lifestyle we have come to expect in our society. As these critical infrastructure systems have evolved, the complexity of their integration has generated numerous challenges as a side effect of increased automation that are more pronounced as the infrastructure ages. Although still a modern technological wonder, the power grid needs a workforce that understands the complex, interdependent facets of the current grid as it evolves to a smarter grid and is pushed closer to its limits through improvements in automated measurement and control. The next generation of technology developers and operators will require an interdisciplinary understanding to reliably and securely integrate advanced communication and control technologies into the infrastructure and create systems to address the new demands of increased renewable and distributed generation, complex markets, and resilience to damaging storms and cyber attacks. Educational institutions need to accept the challenge of weaving the great diversity of contributing disciplines into the common fabric which allows specialties to effectively work together

    Energy Consumption Analysis Using Measured Data from a Net-Zero Energy Commercial Building in a Cold and Dry Climate

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    Zero-energy buildings have a critical role in reducing global energy use and greenhouse gas emissions. However, few studies have analyzed net-zero energy commercial buildings using measured energy use such as whole-building level and end-use level data. This paper presents an energy consumption analysis for the first net-zero energy commercial building in Idaho, U.S., in a cold and dry climate using measured end-use data from this building as well as measured whole-building energy use. Monthly bill data analysis, end-use data analysis, and Energy Use Intensity (EUI) analysis were conducted. The combined analysis of this study shows that the HVAC system was the most sensitive to the outside air temperature, showing different energy use percentages of 48.4%, 35.1% (the heating period), 21.6% (the weather-independent period), and 33.4% (the cooling period), respectively. Lighting had the highest percentage of 35.2% for the weather-independent period. The PV electricity generation was higher than the building electricity use, except from December 2017 to February 2018, and the building was net-positive from an energy perspective. The calculated EUI of the building was 34.2 kWh/m2·y, which can be compared to the EUIs of other net zero energy buildings. The approaches developed in this study can be useful for analyzing several net zero buildings by different weather profiles

    Large Scale Energy Signature Analysis: Tools for Utility Managers and Planners

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    Building energy signature analysis is a well-established tool for understanding the temperature sensitivity of building energy consumption and measuring energy savings. This tool has been used to measure energy savings of residential, commercial, and even industrial buildings. The public availability of electricity loads (i.e., hourly electricity demand (MW)) from entire Balancing Authorities (BAs) provide an interesting opportunity to apply this approach to a large aggregate load. In this paper, we explore that opportunity for BAs and show that the correlations for large geographical areas are surprisingly coherent when the change-point linear regression analysis is used with the daily interval data of electricity demand and outside air temperature. The change-point linear regression models of all the BAs, except WAUW and OVEC, show R2 of 0.70 or more and CV-RMSE of 10.0% or less. We also suggest an analysis method that allows for meaningful comparisons between BAs and to assess changes in time for a given BA which could be used to interpret changes in load patterns year-to-year, accounting for changes in weather. This approach can be used to verify the impact of energy efficiency programs on a building component/system-wide basis. This study shows the annual electricity demand reductions for SCL and IPCO are 136,655 MWh (1.5%) and 182,053 MWh (1.1%), respectively

    Kinematics of Redundantly Actuated Closed Chains

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    The instantaneous kinematics of a hybrid manipulation system, which combines the traditional serial chain geometry with parallelism in actuation, and the problem of coordination is discussed. The indeterminacy and singularities in the inverse kinematics and statics equations and measures of kinematic performance are analyzed. Finally, coordination algorithms that maintain an optimal force distribution between the actuators while avoiding or exploiting singularities are presented

    The Walnut, California, earthquakes of July-August, 1959

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    A swarm of minor earthquakes began on July 29, 1959, near 34° 00′ N, 117° 48′ W. Records at Pasadena show P and S waves reflected from the Moho. A portable instrument recorded some of these at a point about 6 km. from the epicenter. The characteristic false S - P of about one second at short distances was recorded

    Port Elizabeth Circuit: St John's, Havelock Street

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    Bequests made to St. John's Wesleyan Church, Havelock Street, Port Elizabeth

    Contracting Around the Hague Service Convention

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    When a plaintiff wishes to commence an action against a non-resident foreign defendant in an American forum, it may need to serve that defendant with process abroad. The Convention on the Service Abroad of Judicial and Extrajudicial Documents in Civil or Commercial Matters (“Hague Service Convention” or “Convention”) provides a mechanism for achieving that goal. Under the terms of this treaty — which has been ratified by 75 nations — each signatory is required to maintain a central authority that will serve process upon local defendants at the request of U.S. plaintiffs. In practice, however, the act of serving process upon defendants in particular foreign countries may present challenges. In Russia, for example, it is currently impossible for a U.S. plaintiff to serve process upon a defendant because that nation’s central authority refuses to accept requests from the United States. In China, the central authority sometimes takes more than a year to serve process on local defendants. These complications raise the question of whether it is possible for private actors to contract around the Hague Service Convention so as to avoid the need to interact with central authorities in foreign nations. The California Supreme Court will soon take up this issue when it hears oral argument in Rockefeller Technology Investments (Asia) VII v. Changzhou SinoType Technology Company, Ltd. In this Essay, we first discuss how that particular case should be resolved. We explain that while it is possible to contract around the Convention, the language in the parties’ contract in SinoType failed to do so. We then discuss alternative drafting strategies that future parties might utilize in order to succeed where the parties in SinoType failed

    Simulation of Vertical Axis Wind Turbines With Variable Pitch Foils

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    A dynamic computer model of a turbine was developed in MATLAB in order to study the behavior of vertical axis wind turbines (VAWTs) with variable pitch (articulating) foils. The simulation results corroborated the findings of several empirical studies on VAWTs. The model was used to analyze theories of pitch articulation and to inform the discussion on turbine design. Simulations of various models showed that pitch articulation allowed Darrieus-style vertical axis wind turbines to start from rest. Once in motion, the rotor was found to accelerate rapidly to very high rotational velocities. The simulations revealed a plateau region of high efficiency for small-scale Darrieus-style VAWTs with symmetric airfoils at tip speed ratios in the range of 3 to 4 and demonstrated the advantages of using a dynamic generator load

    Centralized and Decentralized Optimal Control of Variable Speed Heat Pumps

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    Utility service providers are often challenged with the synchronization of thermostatically controlled loads. Load synchronization, as a result of naturally occurring and demand-response events, has the potential to damage power distribution equipment. Because thermostatically controlled loads constitute most of the power consumed by the grid at any given time, the proper control of such devices can lead to significant energy savings and improved grid stability. The contribution of this paper is the development of an optimal control algorithm for commonly used variable speed heat pumps. By means of selective peer-to-peer communication, our control architecture allows for the regulation of home temperatures while simultaneously minimizing aggregate power consumption, and aggregate load volatility. An optimal centralized controller is also explored and compared against its decentralized counterpart
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