255 research outputs found
Expendable oceanographic mooring (XMOOR)
An expendable, self-deploying mooring (XMOOR) for shallow water applications has been developed to address Navy
requirements for environmental monitoring. The project has been conducted jointly between the Woods Hole Oceanographic
Institution and the Naval Research Laboratory at Stennis, MS. WHOI has taken the lead on the mechanical design of the
system while NR has developed the electronics.
Eight prototype XMOOR systems have been built. They are designed for water depths between 10 and 100m, for
deployments of up to 3-months duration, and for automatic deployment. Their sensor suite includes barometrc pressure, air
temperatue, water temperature at up to 25 levels, and conductivity and pressure at up to 3 levels. Data telemetry is
accomplished via the Argos DCS and by line-of-sight VH confguration of the data collection program.
This report describes the XMOOR mechanical system. The data collection and telemetry systems are described
separately in (1) and (2).Funding was provided by the Office of Naval Research through Contract Nos.
NOOO-14-92-C-6028 and NOOO-14-95-1-0774
1988 Convocation
Opening Selections: First Class Brass, George Frederich Handel Processional: Jean Joseph Mouret Welcome: Dr. Leon Lederman, Director, Fermi Laboratory, Vice President Board of Trustees; Dr. Stephanie Pace Marshall, Director; David Kung, Student Council President Introductions: Dr. Stephanie Pace Marshall, Director Musical Selection: Franz Von Suppe Keynote Speaker: Dr. Donald Frye, Former Chief Executive Bell & Howell Co., Professor of Industrial Engineering and Management Science, Northwestern University Recessional: George Frederich Hande
The Relationship of Expert-System Scored Constrained Free-Response Items to Multiple-Choice and Open-Ended Items
This study examined the relationship of an expert- system scored constrained free-response item (requir ing the student to debug a faulty computer program) to two other item types: (1) multiple-choice and (2) free- response (requiring production of a program). Confir matory factor analysis was used to test the fit of a three-factor model to these data and to compare the fit of the model to three alternatives. These models were fit using two random-half samples, one given a faulty program containing one bug and the other a program with three bugs. A single-factor model best fit the data for the sample taking the one-bug constrained free re sponse and a two-factor model fit the data somewhat better for the second sample. In addition, the factor intercorrelations showed this item type to be highly re lated to both the free-response and multiple-choice measures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68260/2/10.1177_014662169001400204.pd
MApping the Most Massive Overdensities Through Hydrogen (MAMMOTH) I: Methodology
Modern cosmology predicts that a galaxy overdensity is associated to a large
reservoir of the intergalactic gas, which can be traced by the Ly
forest absorption. We have undertaken a systematic study of the relation
between Coherently Strong intergalactic Ly Absorption systems (CoSLAs),
which have highest optical depth () in distribution, and mass
overdensities on the scales of 10 - 20 comoving Mpc. On such
large scales, our cosmological simulations show a strong correlation between
the effective optical depth () of the CoSLAs and the 3-D mass
overdensities. In moderate signal-to-noise spectra, however, the profiles of
CoSLAs can be confused with high column density absorbers. For , where
the corresponding Ly is redshifted to the optical, we have developed the
technique to differentiate between these two alternatives. We have applied this
technique to SDSS-III quasar survey at - 3.3, and we present a sample
of five CoSLA candidates with on 15 Mpc greater than
the mean optical depth. At lower redshifts of , where the
background quasar density is higher, the overdensity can be traced by
intergalactic absorption groups using multiple sight lines. Our overdensity
searches fully utilize the current and next generation of Ly forest
surveys which cover a survey volume of Gpc). In addition,
systems traced by CoSLAs will build a uniform sample of the most massive
overdensities at to constrain the models of structure formation, and
offer a unique laboratory to study the interactions between galaxy
overdensities and the intergalactic medium.Comment: 24 pages, 30 figures, 8 tables, submitted to the Astrophysical
Journa
The Effect of High Efficiency Building Technologies and PV Generation on the Energy Profiles for Typical US Residences
The penetrations of high efficiency technologies and photovoltaic (PV) generation are increasing in the residential sector. Technologies such as improved insulation and efficient HVAC systems significantly affect the energy profile of a house. This effect varies due to climate characteristics, i.e. temperature, solar radiation, relative humidity, and wind speeds. The effect of other technologies, such as efficient water heaters, lighting, or kitchen appliances, is mainly governed by human behavior, which may be represented by a schedule. This paper studies the performance of both climate-influenced and scheduled household devices among different levels of efficiency through combined computational and experimental methods. Three houses were constructed by the Tennessee Valley Authority and were outfitted with robots that mimicked the occupation of a family. The houses represented three categories of residences, namely, typical builder, retrofit, and near net-zero-energy. With the energy and weather data collected from 2009 to 2014, a total of four house energy models were developed to account for equipment changes throughout the years. The studies performed using these models considered the behavior of the HVAC systems, PV system, and water heaters as well as climate effects
Virtual Power Plant Control for Large Residential Communities Using HVAC Systems for Energy Storage
Heating, ventilation, and air-conditioning (HVAC) systems use the most electricity of any household appliance in residential communities. HVAC system modeling facilitates the study of demand response (DR) at both the residential and power system levels. In this article, the equivalent thermal model of a reference house is proposed. Parameters for the reference house were determined based on the systematic study of experimental data obtained from fully instrumented field demonstrators. Energy storage capacity of HVAC systems is calculated and an equivalent state-of-charge is defined. The uniformity between HVAC systems and battery energy storage system is demonstrated by DR control. The aggregated HVAC load model is based on the reference house and considers a realistic distribution of HVAC parameters derived from one of the largest smart grid field demonstrators in rural America. A sequential DR scheme as part of a virtual power plant control is proposed to reduce both ramping rate and peak power at the aggregated level, while maintaining human comfort according to ASHRAE standards
Demand Response of HVACs in Large Residential Communities Based on Experimental Developments
Heating, ventilation, and air-conditioning (HVAC) systems contribute the largest electricity usage for a residential community. Modeling of the HVAC systems facilitate the study of demand response (DR) at both the residential and the power system level. In this paper, the equivalent thermal model of a reference house was proposed. Parameters for the reference house were determined based on the systematic study of experimental data obtained from fully instrumented field demonstrators. The aggregated HVAC load was modeled based on the reference house while considering a realistic distribution of HVAC parameters derived from data that was provided by one of the largest smart grid field demonstrators in rural America. A sequential DR as part of a Virtual Power Plant (VPP) control was proposed to reduce both ramping rate and peak power at the aggregated level, while maintaining human comfort according to ASHRAE standard
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Prevalence and mapping of hepatitis C infections among men who have sex with men in New York City
Emerging sexually transmitted hepatitis C virus (HCV) epidemics among men who have sex with men (MSM) have been reported worldwide, with higher HCV infection rates among those who are HIV-infected. This study aims to determine prevalence of recent and chronic HCV infections among community-recruited MSM in New York City (NYC), map HCV infections by home, social, and sexual neighborhoods, and identify clusters of genetically linked HCV variants using phylogenetic analysis. The NYC M2M study recruited MSM via modified time-space, venue-based sampling and internet/mobile app-based recruitment during 2010–13. Participants completed a Google Earth map on neighborhoods of where they lived, socialized, and had sex in the last 3 months, an ACASI questionnaire, and a sexual network inventory about their sex partners. The men received HIV testing and provided serum samples. Testing on stored serum samples included HCV antibody and RNA viral load, HCV antibody avidity assay (avidity index 40 years, adjusted odds ratio (aOR) 3.56 (95% CI 1.57, 8.08), HIV-positive serostatus, aOR 3.18 (95% CI 1.40, 7.22), any sexually transmitted infection (STI) in the last 3 months, aOR 2.81 (95% CI 1.11, 7.13), and injection drug use (IDU) ever, aOR 4.34 (95% CI 1.69, 11.17). Mapping of HCV infections differed slightly by home, social, and sexual neighborhoods. Based on phylogenetic analysis from 12 HCV RNA-positive samples, no evidence of a clustered HCV epidemic was found. Overall HCV seroprevalence was 2.8% among community-recruited MSM in NYC, with higher prevalence among HIV-positive MSM compared to HIV-negative MSM. Only two participants were found to have recent HCV infection, with no evidence of a clustered HCV epidemic based on phylogenetic analysis. Our results support testing of HCV infection among HIV-negative MSM if they report having a recent STI and IDU in the past rather than universal HCV testing in all HIV-negative MSM
Recommended from our members
Prevalence and mapping of hepatitis C infections among men who have sex with men in New York City
Emerging sexually transmitted hepatitis C virus (HCV) epidemics among men who have sex with men (MSM) have been reported worldwide, with higher HCV infection rates among those who are HIV-infected. This study aims to determine prevalence of recent and chronic HCV infections among community-recruited MSM in New York City (NYC), map HCV infections by home, social, and sexual neighborhoods, and identify clusters of genetically linked HCV variants using phylogenetic analysis. The NYC M2M study recruited MSM via modified time-space, venue-based sampling and internet/mobile app-based recruitment during 2010–13. Participants completed a Google Earth map on neighborhoods of where they lived, socialized, and had sex in the last 3 months, an ACASI questionnaire, and a sexual network inventory about their sex partners. The men received HIV testing and provided serum samples. Testing on stored serum samples included HCV antibody and RNA viral load, HCV antibody avidity assay (avidity index 40 years, adjusted odds ratio (aOR) 3.56 (95% CI 1.57, 8.08), HIV-positive serostatus, aOR 3.18 (95% CI 1.40, 7.22), any sexually transmitted infection (STI) in the last 3 months, aOR 2.81 (95% CI 1.11, 7.13), and injection drug use (IDU) ever, aOR 4.34 (95% CI 1.69, 11.17). Mapping of HCV infections differed slightly by home, social, and sexual neighborhoods. Based on phylogenetic analysis from 12 HCV RNA-positive samples, no evidence of a clustered HCV epidemic was found. Overall HCV seroprevalence was 2.8% among community-recruited MSM in NYC, with higher prevalence among HIV-positive MSM compared to HIV-negative MSM. Only two participants were found to have recent HCV infection, with no evidence of a clustered HCV epidemic based on phylogenetic analysis. Our results support testing of HCV infection among HIV-negative MSM if they report having a recent STI and IDU in the past rather than universal HCV testing in all HIV-negative MSM
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