Geometric Aspects of Composite Pulses

Unitary operations acting on a quantum system must be robust against systematic errors in control parameters for reliable quantum computing. Composite pulse technique in nuclear magnetic resonance (NMR) realises such a robust operation by employing a sequence of possibly poor quality pulses. In this article, we demonstrate that two kinds of composite pulses, one compensates for a pulse length error in a one-qubit system and the other compensates for a J-coupling error in a twoqubit system, have vanishing dynamical phase and thereby can be seen as geometric quantum gates, which implement unitary gates by the holonomy associated with dynamics of cyclic vectors defined in the text.Comment: 20 pages, 4 figures. Accepted for publication in Philosophical Transactions of the Royal Society

Designing Robust Unitary Gates: Application to Concatenated Composite Pulse

We propose a simple formalism to design unitary gates robust against given systematic errors. This formalism generalizes our previous observation [Y. Kondo and M. Bando, J. Phys. Soc. Jpn. 80, 054002 (2011)] that vanishing dynamical phase in some composite gates is essential to suppress amplitude errors. By employing our formalism, we naturally derive a new composite unitary gate which can be seen as a concatenation of two known composite unitary operations. The obtained unitary gate has high fidelity over a wider range of the error strengths compared to existing composite gates.Comment: 7 pages, 4 figures. Major revision: improved presentation in Sec. 3, references and appendix adde

Report of Energy Efficiency Study and Metering/Utilities Profile for Electricity Deregulation at Prairie View A&M University (PVAMU) Prairie View, Texas

The physical plant director and staff at Prairie View A&M University (PVAMU) do a good job of maintaining PVAMU facilities and keeping expenses down. During our visit, however, we were able to identify several opportunities for improving energy efficiency

A Simple and Quick Chilled Water Loop Balancing for Variable Flow System

For many modem buildings, the chilled water loops and risers are equipped with variable speed pumping systems. How to quickly balance the loop or riser to satisfy the cooling requirement and reduce energy consumption is a very interesting topic today. In this paper, a method for simple and quick balancing of the chilled water risers for a large medical facility has been developed and implemented. Through water loop commissioning, the cold air temperature is maintained very well and the energy consumption for the pumping system is reduced by about 40%

Improving Control of a Dual-Duct Single-Fan Variable Air Volume Systems

This paper discusses improved control strategies for dual-duct single-fan variable air volume (VAV) systems. Common control strategy for supply air volume modulation is evaluated, and an improved air volume control strategy that maintains separate cold and hot air duct static pressure set points is presented. The paper also explores the interactions between the cold and hot deck temperatures and duct static pressures, and discusses the impact of non-ideal deck temperature settings on duct static pressures and overall system energy consumption. To compensate the negative impact of non-ideal cold and hot deck temperature set points, the authors propose using real-time duct static pressure readings as feedback signals to fine-tune the deck temperature set points. These new control schemes can reduce simultaneous cooling and heating while reducing fan power consumption

A Novel Procedure to Determine Optimal Air Static Pressure Set-points and Reset Schedules in VAV Air Handling Units

Air static pressure set-point or schedule for VAV AHLJ systems is one of the most crucial operational parameters for satisfy lug the building load, maintaining the room comfort level and saving energy costs. This paper presents a novel procedure and method, which can be applied to determine the optimal air static pressure set-point for VAV AHUs with both stand-alone controllers and DDC controllers. This procedure provides a simple, fast and a non-intrusive way to obtain the optimal or improved operational schedules without interrupting normal operation of the systems and without detailed simulation. An application example is also presented in this paper

Optimization Measures for Sporting and Special Event Facilities: Design and Operation

Reducing unnecessary building energy costs is becoming more of a priority. Rising fuel prices and a global emphasis on energy efficiency are key contributing factors. This push towards energy efficiency certainly applies to today's athletic and special event facilities. High customer expectations and corresponding large operating expenses have helped to make energy conservation measures more of a priority in the facilities design. The heating, ventilation, and air conditioning (HVAC) systems in sporting and special event facility present a unique challenge to Continuous Commissioning (CC) engineers. In such facilities, high occupancy and equipment loads occur at the design load condition, but only a small fraction of the designed capacity is necessary for routine operations. On the other hand, during games and other events, system performance is critical. Therefore, significant savings potential exists, but care must be taken to avoid compromising the peak load operations. Maintenance uncertainties, equipment wear, and lack of operator knowledge all combine to affect the building operating costs. Continuous Commissioning, a process developed by the Texas A&M Energy Systems Laboratory, addresses issues such as these and proves very worthwhile. An overview of multi-purpose arenas and their usage will be given, and potential optimization measures and Continuous Commissioning of these facilities will be presented, along with some illustrative examples

An Exploratory Initiative for Improving Low-Cost Housing in Texas

In 1996 the Real Estate Center at Texas A&M University released a report indicating that the population of Texas would double in the next 30 years and that a majority of the 18 million new Texans would be have low to very-low incomes. In order to house that many low income persons, it is apparent that a significant number of affordable housing units must be built in a relatively short time frame. Based on these predictions, our interdisciplinary team made a proposal in the Texas Engineering Experiment Station (TEES) Strategic Initiatives Program to explore technologies related to the production of affordable housing. The purpose of the work is to identify opportunities for research into systems, materials, and processes that might contribute to the development of a low-cost housing industry in Texas that could meet state housing needs and might create export possibilities. The proposal was funded by the Texas Engineering Experiment Station, the Center for Housing and Urban Development, and the College of Architecture Research Fund. This report summarizes the results of the effort

Program Overview: The Texas LoanSTAR Program; 1989-October 1999, A 10-Year Experience

The Texas LoanSTAR (Loans to Save Taxes and Resources) program was conceived as a $98.6 million capital retrofit program for building energy efficiency. The funding source is petroleum violation escrow funds (PVE) from the Federal government. LoanSTAR is administered by the Texas State Energy Conservation Office of the Comptroller's Office, under the guidance of Dub Taylor, Director, and is the largest revolving loan fund administered by a state for conservation purposes. LoanSTAR was conceived in 1988 and began in 1989. This paper summarizes the program dollar savings and environmental impact from its inception through October 1999