266 research outputs found
Development of Economic Water Usage Sensor and Cyber-Physical Systems Co-Simulation Platform for Home Energy Saving
In this thesis, two Cyber-Physical Systems (CPS) approaches were considered to reduce residential building energy consumption. First, a flow sensor was developed for residential gas and electric storage water heaters. The sensor utilizes unique temperature changes of tank inlet and outlet pipes upon water draw to provide occupant hot water usage. Post processing of measured pipe temperature data was able to detect water draw events. Conservation of energy was applied to heater pipes to determine relative internal water flow rate based on transient temperature measurements. Correlations between calculated flow and actual flow were significant at a 95% confidence level. Using this methodology, a CPS water heater controller can activate existing residential storage water heaters according to occupant hot water demand. The second CPS approach integrated an open-source building simulation tool, EnergyPlus, into a CPS simulation platform developed by the National Institute of Standards and Technology (NIST). The NIST platform utilizes the High Level Architecture (HLA) co-simulation protocol for logical timing control and data communication. By modifying existing EnergyPlus co-simulation capabilities, NIST’s open-source platform was able to execute an uninterrupted simulation between a residential house in EnergyPlus and an externally connected thermostat controller. The developed EnergyPlus wrapper for HLA co-simulation can allow active replacement of traditional real-time data collection for building CPS development. As such, occupant sensors and simple home CPS product can allow greater residential participation in energy saving practices, saving up to 33% on home energy consumption nationally
An Empirical Examination of Managerial Competencies Among Black Women Entrepreneurs and Black Women Corporate Executives*
The new economic reality of the 1990' s is clearly the M table entrepreneurial pursuits of women business owners in general and black women entrepreneurs in particular. This paper reports on the managerial competencies and perceived skill development needs of black women entrepreneurs and contrasts their profile with black women corporate managers. Managerial competencies were assessed through the use of the "Leadership Competency Inventory" (LCI). The LCI provides feedback on 55 competencies arranged in four categories: (1) Socio-Economic Environment of Business, (2) Technical and Operational Methods, (3) Human Resource and Interpersonal Communication Skills, and (4) Vision and Environmental Co-Alignment Scanning Abilities. Upon testing for significance, the conclusions indicate that a relatively different and distinct competency profile exists and illustrates the developmental needs for black women managers anticipating stepping off the corporate track in favor of the entrepreneurial alternative. As for black women entrepreneurs, they continue 10 display mixed perceptions of their skills and abilities with some areas identified as very weak and others very positively viewed
3D ab initio modeling in cryo-EM by autocorrelation analysis
Single-Particle Reconstruction (SPR) in Cryo-Electron Microscopy (cryo-EM) is
the task of estimating the 3D structure of a molecule from a set of noisy 2D
projections, taken from unknown viewing directions. Many algorithms for SPR
start from an initial reference molecule, and alternate between refining the
estimated viewing angles given the molecule, and refining the molecule given
the viewing angles. This scheme is called iterative refinement. Reliance on an
initial, user-chosen reference introduces model bias, and poor initialization
can lead to slow convergence. Furthermore, since no ground truth is available
for an unsolved molecule, it is difficult to validate the obtained results.
This creates the need for high quality ab initio models that can be quickly
obtained from experimental data with minimal priors, and which can also be used
for validation. We propose a procedure to obtain such an ab initio model
directly from raw data using Kam's autocorrelation method. Kam's method has
been known since 1980, but it leads to an underdetermined system, with missing
orthogonal matrices. Until now, this system has been solved only for special
cases, such as highly symmetric molecules or molecules for which a homologous
structure was already available. In this paper, we show that knowledge of just
two clean projections is sufficient to guarantee a unique solution to the
system. This system is solved by an optimization-based heuristic. For the first
time, we are then able to obtain a low-resolution ab initio model of an
asymmetric molecule directly from raw data, without 2D class averaging and
without tilting. Numerical results are presented on both synthetic and
experimental data
Mexico Beckons Mid-American Small Business: Prospect for University Centered Export Trade Assistance*
Midwestern small business firms are being aggressively beckoned to enter the rapidly growing Mexican economy. With the recent passage of the North American Free Trade Agreement (NAFTA), Mexico is ready to start spending to upgrade its quality of life. Small business firms with products that can help with these improvements are being urged to scour Mexico for trade leads. This study reports on a survey of 1,104 midwest-central small and medium size manufacturing firms who find it difficult to take advantage of the export opportunity that Mexico may offer them. Among the respondents, 287firms are in industries classified by the U.S. Department of Commerce as having the greatest potential for rapid growth in export to Mexico. Characteristics of survey firms are presented along with their managerial and technical assistance needs. The prospect for a university-based export assistance center is explored along with the operational dimensions for such an agency partnership
Smart Control for Home Water Heater Saving
Existing gas or electric water heaters can become inefficient through the overheating of water and through parasitic heat loss. These inefficiencies are able to be solved by monitoring when a home uses hot water. AquAdapt is a smart sensor which is capable of attaching to any existing residential gas or electric water heater. By constantly monitoring the temperature change of a home water heater, the first law of thermodynamics can be used to relate temperature change to the amount of hot water leaving the water heater. Utilizing this information, a schedule can be generated to optimize the heating of home hot water. Regulating the on-off state of a water heater based on the household’s learned usage pattern, allows AquAdapt to reduce residential water heating energy consumption by up to 33%. With a final product cost of $60, the return on investment of AquAdapt is estimated to be 8 months
Lessons for Small Business: Incentive Health Care and Risk Rating Practices
As the health care system reform debate continues, the central challenge of bringing nearly 38 million uninsured American workers under a quality health care plan remains the goal. Another objective that remains clear is that the plan to be implemented will follow the employer-based model which Americans' employers have crafted for over fifty years. Small business owners will be mandated to provide health insurance to all workers, including those who work part-time. This paper examines the health care incentive measures and risk rating practices perceived to be effective cost control mechanisms for small business firms. Conclusions concerning a well-designed incentive program are offered within the context of the Americans With Disabilities Act
Earthmover-based manifold learning for analyzing molecular conformation spaces
In this paper, we propose a novel approach for manifold learning that
combines the Earthmover's distance (EMD) with the diffusion maps method for
dimensionality reduction. We demonstrate the potential benefits of this
approach for learning shape spaces of proteins and other flexible
macromolecules using a simulated dataset of 3-D density maps that mimic the
non-uniform rotary motion of ATP synthase. Our results show that EMD-based
diffusion maps require far fewer samples to recover the intrinsic geometry than
the standard diffusion maps algorithm that is based on the Euclidean distance.
To reduce the computational burden of calculating the EMD for all volume pairs,
we employ a wavelet-based approximation to the EMD which reduces the
computation of the pairwise EMDs to a computation of pairwise weighted-
distances between wavelet coefficient vectors.Comment: 5 pages, 4 figures, 1 tabl
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Autocorrelation analysis for cryo-EM with sparsity constraints: Improved sample complexity and projection-based algorithms
The number of noisy images required for molecular reconstruction in
single-particle cryo-electron microscopy (cryo-EM) is governed by the
autocorrelations of the observed, randomly-oriented, noisy projection images.
In this work, we consider the effect of imposing sparsity priors on the
molecule. We use techniques from signal processing, optimization, and applied
algebraic geometry to obtain new theoretical and computational contributions
for this challenging non-linear inverse problem with sparsity constraints. We
prove that molecular structures modeled as sums of Gaussians are uniquely
determined by the second-order autocorrelation of their projection images,
implying that the sample complexity is proportional to the square of the
variance of the noise. This theory improves upon the non-sparse case, where the
third-order autocorrelation is required for uniformly-oriented particle images
and the sample complexity scales with the cube of the noise variance.
Furthermore, we build a computational framework to reconstruct molecular
structures which are sparse in the wavelet basis. This method combines the
sparse representation for the molecule with projection-based techniques used
for phase retrieval in X-ray crystallography.Comment: 31 pages, 5 figures, 1 movi
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