Showing papers by "Raytheon published in 2011"

The acs nearby galaxy survey treasury. viii. the global star formation histories of 60 dwarf galaxies in the local volume

Abstract: We present uniformly measured star formation histories (SFHs) of 60 nearby (D less than or similar to 4 Mpc) dwarf galaxies based on color-magnitude diagrams of resolved stellar populations from images taken with the Hubble Space Telescope and analyzed as part of the ACS Nearby Galaxy Survey Treasury program (ANGST). This volume-limited sample contains 12 dwarf spheroidal (dSph)/dwarf elliptical (dE), 5 dwarf spiral, 28 dwarf irregular (dI), 12 dSph/dI (transition), and 3 tidal dwarf galaxies. The sample spans a range of similar to 10 mag in MB and covers a wide range of environments, from highly interacting to truly isolated. From the best-fit SFHs, we find three significant results for dwarf galaxies in the ANGST volume: (1) the majority of dwarf galaxies formed the bulk of their mass prior to z similar to 1, regardless of current morphological type; (2) the mean SFHs of dIs, transition dwarf galaxies (dTrans), and dSphs are similar over most of cosmic time, and only begin to diverge a few Gyr ago, with the clearest differences between the three appearing during the most recent 1 Gyr; and (3) the SFHs are complex and the mean values are inconsistent with simple SFH models, e. g., single bursts, constant star formation rates (SFRs), or smooth, exponentially declining SFRs. The mean SFHs show clear divergence from the cosmic SFH at z less than or similar to 0.7, which could be evidence that low-mass systems have experienced delayed star formation relative to more massive galaxies. The sample shows a strong density-morphology relationship, such that the dSphs in the sample are less isolated than the dIs. We find that the transition from a gas-rich to gas-poor galaxy cannot be solely due to internal mechanisms such as stellar feedback, and instead is likely the result of external mechanisms, e. g., ram pressure and tidal stripping and tidal forces. In terms of their environments, SFHs, and gas fractions, the majority of the dTrans appear to be low-mass dIs that simply lack Ha emission, similar to Local Group (LG) dTrans DDO 210. However, a handful of dTrans have remarkably low gas fractions, suggesting that they have nearly exhausted their gas supply, analogous to LG dTrans such as Phoenix. Finally, we have also included extensive exploration of uncertainties in the SFH recovery method, including the optimization of time resolution, the effects of photometric depth, and impact of systematic uncertainties due to the limitations in current stellar evolution models.

Association Between Biologic Therapies for Chronic Plaque Psoriasis and Cardiovascular Events: A Meta-analysis of Randomized Controlled Trials

Abstract: Context Ustekinumab and briakinumab, monoclonal antibodies to the shared p40 subunit of interleukin (IL)-12 and IL-23, have shown efficacy in treating chronic plaque psoriasis (CPP). Preliminary reports of major adverse cardiovascular events (MACEs) in psoriasis patients receiving anti–IL-12/23 agents have prompted concern. Objective To evaluate a possible association between biologic therapies for CPP and MACEs via meta-analysis. Data Sources Randomized controlled trials (RCTs) of anti–IL-12/23 (ustekinumab and briakinumab) agents and anti–tumor necrosis factor α (TNF-α) agents (adalimumab, etanercept, and infliximab) used in treating CPP were reviewed using the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and Ovid MEDLINE from database inception to May 2011. The results of registered nonpublished completed studies were procured through abstract publications or poster presentations. Study Selection Randomized, placebo-controlled, double-blind, monotherapy studies (with safety outcome data for MACE) of IL-12/23 antibodies and anti–TNF-α agents in adults. Studies of psoriatic arthritis were excluded. Data Extraction Two investigators independently searched data while 6 investigators reviewed the abstracted data. Results A total of 22 RCTs comprising 10 183 patients met the predefined inclusion criteria. The primary outcome measure was MACE, a composite end point of myocardial infarction, cerebrovascular accident, or cardiovascular death during the placebo-controlled phase of treatment in patients receiving at least 1 dose of study agent or placebo. Absolute risk differences were used as an effect measure. There was no evidence of statistical heterogeneity across the studies using the I 2 statistic (I 2 = 0), allowing for combination of trial results using the Mantel-Haenszel fixed-effects method. During the placebo-controlled phases of the anti–IL-12/23 studies, 10 of 3179 patients receiving anti–IL-12/23 therapies experienced MACEs compared with zero events in 1474 patients receiving placebo (Mantel-Haenszel risk difference, 0.012 events/person-year; 95% confidence interval [CI], −0.001 to 0.026; P =.12). In the anti–TNF-α trials, only 1 of 3858 patients receiving anti–TNF-α agents experienced a MACE compared with 1 of 1812 patients receiving placebo (Mantel-Haenszel risk difference, −0.0005 events/person-year; 95% CI, −0.010 to 0.009; P = .94). Conclusions Compared with placebo, there was no significant difference in the rate of MACEs observed in patients receiving anti–IL-12/IL-23 antibodies or anti–TNF-α treatments. This study may have been underpowered to identify a significant difference.

Distributed malware detection

Abstract: According to one embodiment, a computer-implemented method includes accessing, using one or more processing units, a first file of a plurality of files requested to be analyzed for malware. Each of the plurality of files corresponds to a respective remote client of a plurality of remote clients. Further, the method includes: processing, using the one or more processing units, an analysis of the first file for malware; and generating an output comprising an indication of whether the first file comprises malware. The method also includes accessing, using the one or more processing units, an address for a first remote client of the plurality of remote clients. The first remote client is the respective remote client corresponding to the first file. In addition, the method includes: sending, using the one or more processing units, the output in a communication addressed to the first remote client corresponding to the first file.

Association of Myocardial Enzyme Elevation and Survival Following Coronary Artery Bypass Graft Surgery

Abstract: confidenceinterval[CI],0.36%-1.02%)for0to1,0.86%(95%CI,0.49%-1.40%)for 1t o2, 0.95% (95% CI, 0.72%-1.22%) for 2 to 5, 2.09% (95% CI, 1.69%-2.57%) for5to10,2.78%(95%CI,2.12%-3.58%)for10to20,and7.06%(95%CI,5.46%8.96%) for 20 to 40. Of the variables considered, the CK-MB ratio was the strongest independent predictor of death to 30 days and remained significant even after adjusting for a wide range of baseline risk factors (

Evaluating an evidence-based bundle for preventing surgical site infection: a randomized trial.

Abstract: Objective To determine if an evidence-based practice bundle would result in a significantly lower rate of surgical site infections (SSIs) when compared with standard practice. Design Single-institution, randomized controlled trial with blinded assessment of main outcome. The trial opened in April 2007 and was closed in January 2010. Setting Veterans Administration teaching hospital. Patients Patients who required elective transabdominal colorectal surgery were eligible. A total of 241 subjects were approached, 211 subjects were randomly allocated to 1 of 2 interventions, and 197 were included in an intention-to-treat analysis. Interventions Subjects received either a combination of 5 evidenced-based practices (extended arm) or were treated according to our current practice (standard arm). The interventions in the extended arm included (1) omission of mechanical bowel preparation; (2) preoperative and intraoperative warming; (3) supplemental oxygen during and immediately after surgery; (4) intraoperative intravenous fluid restriction; and (5) use of a surgical wound protector. Main outcome measure Overall SSI rate at 30 days assessed by blinded infection control coordinators using standardized definitions. Results The overall rate of SSI was 45% in the extended arm of the study and 24% in the standard arm (P = .003). Most of the increased number of infections in the extended arm were superficial incisional SSIs (36% extended arm vs 19% standard arm; P = .004). Multivariate analysis suggested that allocation to the extended arm of the trial conferred a 2.49-fold risk (95% confidence interval, 1.36-4.56; P = .003) independent of other factors traditionally associated with SSI. Conclusions An evidence-based intervention bundle did not reduce SSIs. The bundling of interventions, even when the constituent interventions have been individually tested, does not have a predictable effect on outcome. Formal testing of bundled approaches should occur prior to implementation.

Review of high power isolated bi-directional DC-DC converters for PHEV/EV DC charging infrastructure

Abstract: PHEV/EV DC charging infrastructure attracts more and more attention recently. High power isolated bi-directional DC-DC converters provide galvanic isolation, V2G capability and reduce the cost and footprint of the system. Maintaining high power efficiency in wide vehicle battery pack voltage range is required. Three full bridge based high power bi-directional DC-DC converters are conceptually designed for this application and their advantages and disadvantages are addressed. Experimental test bench is built and efficiency evaluation for bi-directional operation is reported.

A 1.2–1.6-GHz Substrate-Integrated-Waveguide RF MEMS Tunable Filter

Abstract: This paper presents a high-performance substrate-integrated-waveguide RF microelectromechanical systems (MEMS) tunable filter for 1.2-1.6-GHz frequency range. The proposed filter is developed using packaged RF MEMS switches and utilizes a two-layer structure that effectively isolates the cavity filter from the RF MEMS switch circuitry. The two-pole filter implemented on RT/Duroid 6010LM exhibits an insertion loss of 2.2-4.1 dB and a return loss better than 15 dB for all tuning states. The relative bandwidth of the filter is 3.7 ± 0.5% over the tuning range. The measured Qu of the filter is 93-132 over the tuning range, which is the best reported Q in filters using off-the-shelf RF MEMS switches on conventional printed circuit board substrates. In addition, an upper stopband rejection better than 28 dB is obtained up to 4.0 GHz by employing low-pass filters at the bandpass filter terminals at the cost of 0.7-1.0-dB increase in the insertion loss.

Coaxial waveguide antenna

Abstract: Processes and systems for radiating electromagnetic energy from an open-ended coaxial cavity are described herein. An antenna assembly includes an open-ended coaxial radiator. The coaxial assembly includes an inner electrically conducting surface and an outer conductive surface spaced apart from and opposing the inner electrically surface. More than one radially aligned electromagnetic coupling modules are positioned at least partially within the coaxial waveguide along different rotation angles. Each of the different electromagnetic coupling modules samples a local electric field, amplifies the sampled field, and alters a phase of at least one of the amplified fields. The amplified, phase-adjusted coaxial fields are radiated from an open end of the coaxial cavity. Although described for transmission mode, the structure can be operated in receive mode by similarly detecting radiated electric fields, amplifying and applying a phase offset, and radiating the amplified, phase offset fields into an open-ended coaxial cavity.

Monolithic microwave integrated circuits (mmics) having conductor-backed coplanar waveguides and method of designing such mmics

Abstract: A MMIC having: a substrate; a plurality of active and passive electrical elements disposed on a top surface of the substrate; a plurality of coplanar waveguide transmission line sections disposed on the top surface of the substrate for electrically interconnecting the active and passive electrical elements; an electrical conductor disposed on a bottom surface of the substrate under the coplanar waveguide section. Edges of ground plane conductors of the coplanar waveguide (CPW) sections have slots therein in regions thereof connected to the active and passive devices. The design of such circuit includes mathematical models of the CPW with the pair of local ground planes and the strip conductor thereof have relatively narrow connectable ports.

Beam shaping of rf feed energy for reflector-based antennas

Abstract: A beam-shaping element is provided to shape RF feed energy for reflector-based antennas. The RF beam-shaping element is located between the primary reflector and the antenna feed and configured to direct RF energy from the feed away from a blockage created by the feed itself towards unblocked regions of the primary reflector. The beam-shaping element allows for a simplified feed design. The feed may comprise one or more feed elements, each comprising a radiating element and a feed to the radiating element such as a cavity-backed slot radiator and stripline trace. In a monopulse tracking system, each quadrant may include only a single feed element. In common aperture systems, the RF beam-shaping element may be formed on only the rear surface of the secondary reflector that allows transmission at the predefined RF wavelength while reflecting energy of a second predetermined wavelength to another sensor.

W-band GaN power amplifier MMICs

Abstract: An advanced high power, high frequency GaN semiconductor process has made possible the design and fabrication of W-band power amplifier MMICs with unprecedented performance. The key enabling semiconductor technology is a 150 nm T-gate GaN HEMT with an output power exceeding 300mW and a peak PAE (power added efficiency) of 37%. With this process, W-band power amplifier MMICs have been designed and fabricated that demonstrate output powers of 1.7 watts, power added efficiencies greater than 20%, and small signal gains of 21 dB. In addition, the compactness of these MMIC designs have allowed for MMIC power densities (MMIC output power relative to MMIC area) exceeding 1/2 watt/mm2.

Opportunistic Cooperation in Cognitive Femtocell Networks

Abstract: We investigate opportunistic cooperation between unlicensed secondary users and legacy primary users in a cognitive radio network. Specifically, we consider a model of a cognitive network where a secondary user can cooperatively transmit with the primary user in order to improve the latter's effective transmission rate. In return, the secondary user gets more opportunities for transmitting its own data when the primary user is idle. This kind of interaction between the primary and secondary users is different from the traditional dynamic spectrum access model in which the secondary users try to avoid interfering with the primary users while seeking transmission opportunities on vacant primary channels. In our model, the secondary users need to balance the desire to cooperate more (to create more transmission opportunities) with the need for maintaining sufficient energy levels for their own transmissions. Such a model is applicable in the emerging area of cognitive femtocell networks. We formulate the problem of maximizing the secondary user throughput subject to a time average power constraint under these settings. This is a constrained Markov Decision Problem and conventional solution techniques based on dynamic programming require either extensive knowledge of the system dynamics or learning based approaches that suffer from large convergence times. However, using the technique of Lyapunov optimization, we design a novel greedy and online control algorithm that overcomes these challenges and is provably optimal.

Multifunctional Software-Defined Radar Sensor and Data Communication System

Abstract: Orthogonal frequency-division multiplexing (OFDM) signal coding and system architecture were implemented to achieve radar and data communication functionalities. The resultant system is a software-defined unit, which can be used for range measurements, radar imaging, and data communications. Range reconstructions were performed for ranges up to 4 m using trihedral corner reflectors with approximately 203 m of radar cross section at the carrier frequency; range resolution of approximately 0.3 m was demonstrated. Synthetic aperture radar (SAR) image of a single corner reflector was obtained; SAR signal processing specific to OFDM signals is presented. Data communication tests were performed in radar setup, where the signal was reflected by the same target and decoded as communication data; bit error rate of was achieved at 57 Mb/s. The system shows good promise as a multifunctional software-defined sensor which can be used in radar sensor networks.

The ACS LCID Project. V. The Star Formation History of the Dwarf Galaxy LGS-3: Clues to Cosmic Reionization and Feedback

Abstract: We present an analysis of the star formation history (SFH) of the transition-type (dIrr/dSph) Local Group galaxy LGS-3 (Pisces) based on deep photometry obtained with the Advanced Camera for Surveys onboard the Hubble Space Telescope. Our observations reach the oldest main-sequence turnoffs at high signal to noise, allowing a time resolution at the oldest ages of σ ~ 1.1 Gyr. Our analysis, based on three different SFH codes, shows that the SFH of LGS-3 is dominated by a main episode ~11.7 Gyr ago with a duration of ~1.4 Gyr. Subsequently, LGS-3 continued forming stars until the present, although at a much lower rate. Roughly 90% of the stars in LGS-3 were formed in the initial episode of star formation. Extensive tests of self-consistency, uniqueness, and stability of the solution have been performed together with the IAC-star/IAC-pop/MinnIAC codes, and these results are found to be independent of the photometric reduction package, the stellar evolution library, and the SFH recovery method. There is little evidence of chemical enrichment during the initial episode of star formation, after which the metallicity increased more steeply reaching a present-day value of Z ~ 0.0025. This suggests a scenario in which LGS-3 first formed stars mainly from infalling fresh gas, and after about 9 Gyr ago, from a larger fraction of recycled gas. The lack of early chemical enrichment is in contrast to that observed in the isolated dSph galaxies of comparable luminosity, implying that the dSphs were more massive and subjected to more tidal stripping. We compare the SFH of LGS-3 with expectations from cosmological models. Most or all the star formation was produced in LGS-3 after the reionization epoch, assumed to be completed at z ~ 6 or ~12.7 Gyr ago. The total mass of the galaxy is estimated to be between 2 and 4 × 108 M ☉ corresponding to circular velocities between 28 km s–1 and 36 km s–1. These values are close to but somewhat above the limit of 30 km s–1 below which the UV background is expected to prevent any star formation after reionization. Feedback from supernovae (SNe) associated with the initial episode of star formation (mechanical luminosity from SNe Lw = 5.3 × 1038 erg s–1) is probably inadequate to completely blow away the gas. However, the combined effects of SN feedback and UV background heating might be expected to completely halt star formation at the reionization epoch for the low mass of LGS-3; this suggests that self-shielding is important to the early evolution of galaxies in this mass range.

Methods and apparatus for volumetric coverage with image beam super-elements

Abstract: Methods and apparatus for a super-element assembly for a phased array radar aperture, the super-element assembly having a first port and a second port to receive a first signal at the first port to generate a main beam, and receive a second signal at the second port to generate an image beam for generating scan volume coverage using the main and image beams.

Polar codes for classical-quantum channels

Abstract: Holevo, Schumacher, and Westmoreland's coding theorem guarantees the existence of codes that are capacity-achieving for the task of sending classical data over a channel with classical inputs and quantum outputs. Although they demonstrated the existence of such codes, their proof does not provide an explicit construction of codes for this task. The aim of the present paper is to fill this gap by constructing near-explicit "polar" codes that are capacity-achieving. The codes exploit the channel polarization phenomenon observed by Arikan for the case of classical channels. Channel polarization is an effect in which one can synthesize a set of channels, by "channel combining" and "channel splitting," in which a fraction of the synthesized channels are perfect for data transmission while the other fraction are completely useless for data transmission, with the good fraction equal to the capacity of the channel. The channel polarization effect then leads to a simple scheme for data transmission: send the information bits through the perfect channels and "frozen" bits through the useless ones. The main technical contributions of the present paper are threefold. First, we leverage several known results from the quantum information literature to demonstrate that the channel polarization effect occurs for channels with classical inputs and quantum outputs. We then construct linear polar codes based on this effect, and the encoding complexity is O(N log N), where N is the blocklength of the code. We also demonstrate that a quantum successive cancellation decoder works well, in the sense that the word error rate decays exponentially with the blocklength of the code. For this last result, we exploit Sen's recent "non-commutative union bound" that holds for a sequence of projectors applied to a quantum state.

Performance Comparison of Long-Wavelength Infrared Type II Superlattice Devices with HgCdTe

Abstract: The InAs/GaSb family of type II superlattices (T2SL) is the only known infrared (IR) detector material having a theoretically predicted higher performance than HgCdTe. The Auger lifetime has been predicted to be much longer, offering the possibility of much lower dark currents. In this paper the present state of the technology for long-wavelength infrared (LWIR) applications is evaluated by examining the dark current density in LWIR T2SL diodes at 78 K as a function of device cutoff wavelength, and comparing it with the HgCdTe benchmark known as Rule 07. The dark current density remains greater than Rule 07, but it has rapidly decreased in recent years with advancing technology, particularly due to innovative barrier structures.

Continued benefit from paclitaxel-eluting compared with bare-metal stent implantation in saphenous vein graft lesions during long-term follow-up of the SOS (Stenting of Saphenous Vein Grafts) trial

Abstract: Objectives This study sought to report the long-term outcomes after drug-eluting stent (DES) implantation in saphenous vein graft (SVG) lesions in the SOS (Stenting of Saphenous Vein Grafts) trial. Background The long-term outcomes after DES implantation in SVGs are poorly studied. Apart from the SOS trial, the only other randomized trial comparing DES with bare-metal stents (BMS) in SVGs reported higher mortality in the DES group at 32 months. Methods In the SOS trial, 80 patients with 112 lesions in 88 SVGs were randomized to a BMS or paclitaxel-eluting stent (PES) and demonstrated improved short-term angiographic and clinical outcomes with PES. Extended clinical follow-up was subsequently obtained. Results Mean age was 67 ± 9 years, and all patients were men. The indications for stenting included acute coronary syndrome in 60% and stable angina in 31% of patients. The mean SVG age was 12 ± 6 years. The baseline characteristics of the patients in the 2 study groups were similar. Procedural success was achieved in 77 patients (96%). During a median follow-up of 35 months, compared with patients randomized to BMS, those receiving PES had a lower incidence of myocardial infarction (hazard ratio [HR]: 0.32, p = 0.01), target lesion revascularization (HR: 0.20, p = 0.004), target vessel revascularization (HR: 0.41, p = 0.03), and target vessel failure (HR: 0.34, p = 0.001) as well as a trend toward less definite or probable stent thrombosis (HR: 0.15, p = 0.08). All-cause mortality (HR: 2.04, p = 0.19) and cardiac mortality (HR: 0.62, p = 0.51) did not differ between groups. Conclusions During long-term follow-up, use of PES was associated with significantly better clinical outcomes than BMS in SVG lesions. (Stenting of Saphenous Vein Grafts Trial [SOS]; NCT00247208 )

The North American and Pelican Nebulae. II. MIPS Observations and Analysis

Abstract: We present observations of ~7 deg^2 of the North American and Pelican Nebulae region at 24, 70, and 160 μm with the Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS). We incorporate the MIPS observations with earlier Spitzer Infrared Array Camera (IRAC) observations, as well as archival near-infrared (IR) and optical data. We use the MIPS data to identify 1286 young stellar object (YSO) candidates. IRAC data alone can identify 806 more YSO candidates, for a total of 2076 YSO candidates. Prior to the Spitzer observations, there were only ~200 YSOs known in this region. Three subregions within the complex are highlighted as clusters: the Gulf of Mexico, the Pelican, and the Pelican's Hat. The Gulf of Mexico cluster is subject to the highest extinction (AV at least ~30) and has the widest range of infrared colors of the three clusters, including the largest excesses and by far the most point-source detections at 70 μm. Just 3% of the cluster members were previously identified; we have redefined this cluster as about 10-100 times larger (in projected area) than was previously realized.

High Temperature Silicon Carbide CMOS Integrated Circuits

Abstract: The wide band-gap of Silicon Carbide (SiC) makes it a material suitable for high temperature integrated circuits [1], potentially operating up to and beyond 450°C. This paper describes the development of a 15V SiC CMOS technology developed to operate at high temperatures, n and p-channel transistor and preliminary circuit performance over temperature achieved in this technology.

Observational constraints on red and blue helium burning sequences

Abstract: We derive the optical luminosity, colors, and ratios of the blue and red helium burning (HeB) stellar populations from archival Hubble Space Telescope observations of nineteen starburst dwarf galaxies and compare them with theoretical isochrones from Padova stellar evolution models across metallicities from Z = 0.001 to 0.009. We find that the observational data and the theoretical isochrones for both blue and red HeB populations overlap in optical luminosities and colors and the observed and predicted blue to red HeB ratios agree for stars older than 50 Myr over the time bins studied. These findings confirm the usefulness of applying isochrones to interpret observations of HeB populations. However, there are significant differences, especially for the red HeB population. Specifically, we find (1) offsets in color between the observations and theoretical isochrones of order 0.15 mag (0.5 mag) for the blue (red) HeB populations brighter than MV ~ –4 mag, which cannot be solely due to differential extinction; (2) blue HeB stars fainter than MV ~ –3 mag are bluer than predicted; (3) the slope of the red HeB sequence is shallower than predicted by a factor of ~3; and (4) the models overpredict the ratio of the most luminous blue to red HeB stars corresponding to ages 50 Myr. Additionally, we find that for the more metal-rich galaxies in our sample (Z 0.5 Z ☉), the red HeB stars overlap with the red giant branch stars in the color-magnitude diagrams, thus reducing their usefulness as indicators of star formation for ages 100 Myr.

Lubrication system with tolerance for reduced gravity

Abstract: A lubrication system includes an auxiliary lubricant tank 48 , a supply conduit 58 extending from a source of lubricant 26 to the auxiliary lubricant tank. A reduced-G bypass line 108 branches from the conduit and enters the auxiliary tank at a first elevation E 1 . The system also includes an auxiliary tank discharge conduit 116 , a portion of which resides within the tank. The resident portion has an opening 122 at least partially at a second elevation E 2 higher than the first elevation.

Hybrid structure airfoil

Abstract: A hybrid airfoil for a gas turbine engine is provided that includes a body and a panel. The body has a first side and a second side orientated opposite the first side. The first and second sides extend between a tip, a base, a leading edge and a trailing edge. The body includes a plurality of cavities disposed in the first side of the body, which cavities extend inwardly toward the second side. The cavities collectively form an opening. At least one rib is disposed between the cavities. A shelf is disposed around the opening. The panel is attached to the shelf first mounting surface and to the rib, and is sized to enclose the opening. The panel is a load bearing structure operable to transfer loads to the body and receive loads from the body.

Use of Trial 1 of the Test of Memory Malingering (TOMM) as a Screening Measure of Effort: Suggested Discontinuation Rules

Abstract: Trial 1 of the Test of Memory Malingering (TOMM) has been suggested as a screening tool, with several possible cut-off scores proposed. The purpose of the present study was to replicate the utility of previously suggested cut-off scores and to characterize neuropsychological profiles of persons who "pass" the TOMM but obtain Trial 1 scores < 45 and of persons with cognitive disorders. A total of 229 veterans were administered the TOMM as part of a neuropsychological evaluation. Trial 1 scores ≥ 41 and ≤ 25 showed good utility as discontinuation scores for adequate and poor effort, respectively, beyond which administration of additional trials were unnecessary. Findings suggest better Trial 1 performance is significantly related to better speeded mental flexibility and memory.

Multi-nodal malware analysis

Abstract: A computer-implemented method includes accessing, by an analysis console, information related to a first file received at a first host of a plurality of hosts. Each host is capable of running a corresponding set of malware detection processes. The information includes: an identifier of the first file; and data indicating a first result of the first host applying the set of malware detection processes to the first file. The identifier is generated by the first host and is usable by each of the hosts to determine whether a second file comprises content substantially equivalent to content of the first file. The analysis console generates a first output including: the identifier of the first file; and a second result indicating whether the first file comprises malware. The second result is usable by each of the hosts to determine whether the second file comprises malware. The first output is propagated to the hosts.

How typical are the local group dwarf galaxies

Abstract: We compare the cumulative star formation histories (SFHs) of Local Group (LG) dwarf galaxies with those in the volume-limited ACS Nearby Galaxy Survey Treasury (ANGST) sample (D 4 Mpc), in order to understand how typical the LG dwarf galaxies are relative to those in the nearby universe. The SFHs were derived in a uniform manner from high-quality optical color-magnitude diagrams constructed from Hubble Space Telescope imaging. We find that the mean cumulative SFHs of the LG dwarfs are comparable to the mean cumulative SFHs of the ANGST sample for the three different morphological types (dwarf spheroidals/ellipticals: dSph/dE; dwarf irregulars: dI; transition dwarfs: dTrans). We also discuss effects such as population gradients and systematic uncertainties in the stellar models that may influence the derived SFHs. Both the ANGST and LG dwarf galaxies show a consistent and strong morphology-density relationship, emphasizing the importance of environment in the evolution of dwarf galaxies. Specifically, we confirm that dIs are found at lower densities and higher luminosities than dSphs, within this large sample. We also find that dTrans are located in similar environments to those occupied by dwarf irregular galaxies, but have systematically lower luminosities that are more comparable to those of dwarf spheroidals. The similarity of the SFHs and morphology-density relationships of the LG and ANGST dwarf galaxies suggests that the LG dwarfs are a good representation of dwarf galaxies in the local universe.

Intrusion detection and tracking system

Abstract: In one aspect, a method to detect an object in an area includes forming a wireless network among a plurality of nodes, each of the nodes being configured to generate an electromagnetic field (EMF) in the area and determining changes in the EMF between two nodes based on: a first difference in received signal strength values between a previously determined received signal strength value and a currently determined received signal strength value, a second difference in received signal strength values between the currently determined received signal strength value and an average received signal strength value and a third difference in link quality values between a previously determined link quality value and a currently determined link quality value. The method further comprises detecting the object based on the changes in the EMF.

The formation of kiloparsec-scale h i holes in dwarf galaxies* **

Abstract: The origin of kpc-scale holes in the atomic hydrogen (H i) distributions of some nearby dwarf irregular galaxies presents an intriguing problem. Star formation histories (SFHs) derived from resolved stars give us the unique opportunity to study past star-forming events that may have helped shape the currently visible Hi distribution. Our sample of five nearby dwarf irregular galaxies spans over an order of magnitude in both total Hi mass and absolute B-band magnitude and is at the low-mass end of previously studied systems. We use Very Large Array Hi line data to estimate the energy required to create the centrally dominant hole in each galaxy. We compare this energy estimate to the past energy released by the underlying stellar populations computed from SFHs derived from data taken with the Hubble Space Telescope. The inferred integrated stellar energy released within the characteristic ages exceeds our energy estimates for creating the holes in all cases, assuming expected efficiencies. Therefore, it appears that stellar feedback provides sufficient energy to produce the observed holes. However, we find no obvious signature of single star-forming events responsible for the observed structures when comparing the global SFHs of each galaxy in our sample to each other or to those of dwarf irregular galaxies reported in the literature. We also fail to find evidence of a central star cluster in FUV or Hα imaging. We conclude that large Hi holes are likely formed from multiple generations of star formation and only under suitable interstellar medium conditions.

THE PROGENITOR MASS OF SN 2011dh FROM STELLAR POPULATION ANALYSIS

Abstract: Using Hubble Space Telescope photometry, we characterize the age of the stellar association in the vicinity of supernova (SN) 2011dh and use it to infer the zero-age main-sequence mass (M ZAMS) of the progenitor star. We find two distinct and significant star formation (SF) events with ages of 29 and 13+2 ? 1 M ?, respectively. These two bursts represent 18+4 ? 9% (young) and 64+10 ? 14% (old) of the total SF in the last 50?Myr. Adopting these fractions as probabilities suggests that the most probable M ZAMS is 13+2 ? 1 M ?. These results are most sensitive to the luminosity function along the well-understood main sequence (MS) and are less sensitive to uncertain late-stage stellar evolution. Therefore, they stand even if the progenitor suffered disruptive post-MS evolution (e.g., eruptive mass loss or binary Roche-lobe overflow). Progenitor identification will help to further constrain the appropriate population. Even though pre-explosion images show a yellow supergiant (YSG) at the site of the SN, panchromatic SN light curves suggest a more compact star as the progenitor. In spite of this, our results suggest an association between the YSG and the SN. Not only was the star located at the SN site, but reinforcing an association, the star's bolometric luminosity is consistent with the final evolutionary stage of the 17?Myr old starburst. If the YSG disappears, then M ZAMS = 13+2 ? 1 M ?, but if it persists, then our results allow the possibility that the progenitor was an unseen star of >29 M ?.

Estimating ionospheric delay using kriging: 1. Methodology

Abstract: [1] The Wide Area Augmentation System (WAAS) is an augmentation of the Global Positioning System (GPS) that provides safe and reliable use of GPS signals for airline navigation over much of North America. Ever since WAAS was first commissioned in July of 2003, the vertical delay estimate at each node in the WAAS ionospheric grid has been determined from a planar fit of slant delay measurements, projected to vertical using an obliquity factor specified by the standard thin shell model of the ionosphere. In a future WAAS upgrade (WAAS Follow-On Release 3), however, the vertical delay will be estimated by an established, geo-statistical technique known as kriging. When compared to the planar fit model, the kriging model is generally found to match better the observed random structure of the vertical delay. This paper presents the kriging methodology to be used to estimate the vertical delay and its uncertainty at each ionospheric grid point. In addition, it provides examples of the improvement in delay accuracy achieved. Under disturbed conditions, the implementation of kriging reduces the magnitude of the root mean square fit residual by up to 15%.