A Simple Exact Error Rate Analysis for DS-CDMA with Arbitrary Pulse Shape in Flat Nakagami Fading

NASA Astrophysics Data System (ADS)

Rahman, Mohammad Azizur; Sasaki, Shigenobu; Kikuchi, Hisakazu; Harada, Hiroshi; Kato, Shuzo

A simple exact error rate analysis is presented for random binary direct sequence code division multiple access (DS-CDMA) considering a general pulse shape and flat Nakagami fading channel. First of all, a simple model is developed for the multiple access interference (MAI). Based on this, a simple exact expression of the characteristic function (CF) of MAI is developed in a straight forward manner. Finally, an exact expression of error rate is obtained following the CF method of error rate analysis. The exact error rate so obtained can be much easily evaluated as compared to the only reliable approximate error rate expression currently available, which is based on the Improved Gaussian Approximation (IGA).

MAI statistics estimation and analysis in a DS-CDMA system

NASA Astrophysics Data System (ADS)

Alami Hassani, A.; Zouak, M.; Mrabti, M.; Abdi, F.

2018-05-01

A primary limitation of Direct Sequence Code Division Multiple Access DS-CDMA link performance and system capacity is multiple access interference (MAI). To examine the performance of CDMA systems in the presence of MAI, i.e., in a multiuser environment, several works assumed that the interference can be approximated by a Gaussian random variable. In this paper, we first develop a new and simple approach to characterize the MAI in a multiuser system. In addition to statistically quantifying the MAI power, the paper also proposes a statistical model for both variance and mean of the MAI for synchronous and asynchronous CDMA transmission. We show that the MAI probability density function (PDF) is Gaussian for the equal-received-energy case and validate it by computer simulations.

Randomizer for High Data Rates

NASA Technical Reports Server (NTRS)

Garon, Howard; Sank, Victor J.

2018-01-01

NASA as well as a number of other space agencies now recognize that the current recommended CCSDS randomizer used for telemetry (TM) is too short. When multiple applications of the PN8 Maximal Length Sequence (MLS) are required in order to fully cover a channel access data unit (CADU), spectral problems in the form of elevated spurious discretes (spurs) appear. Originally the randomizer was called a bit transition generator (BTG) precisely because it was thought that its primary value was to insure sufficient bit transitions to allow the bit/symbol synchronizer to lock and remain locked. We, NASA, have shown that the old BTG concept is a limited view of the real value of the randomizer sequence and that the randomizer also aids in signal acquisition as well as minimizing the potential for false decoder lock. Under the guidelines we considered here there are multiple maximal length sequences under GF(2) which appear attractive in this application. Although there may be mitigating reasons why another MLS sequence could be selected, one sequence in particular possesses a combination of desired properties which offsets it from the others.

Multiple channel programmable coincidence counter

DOEpatents

Arnone, Gaetano J.

1990-01-01

A programmable digital coincidence counter having multiple channels and featuring minimal dead time. Neutron detectors supply electrical pulses to a synchronizing circuit which in turn inputs derandomized pulses to an adding circuit. A random access memory circuit connected as a programmable length shift register receives and shifts the sum of the pulses, and outputs to a serializer. A counter is input by the adding circuit and downcounted by the seralizer, one pulse at a time. The decoded contents of the counter after each decrement is output to scalers.

VSAT communications networks - An overview

NASA Astrophysics Data System (ADS)

Chakraborty, D.

1988-05-01

The very-small-aperture-terminal (VSAT) fixed satellite communication network is a star network in which many dispersed micro terminals attempt to send data in a packet form through a random access/time-division multiple-access (RA/TDMA) satellite channel with transmission delay. The basic concept of the VSAT and its service potential are discussed. Two classes of traffic are addressed, namely, business-oriented low-rate-data traffic and bulk data traffic of corporate networks. Satellite access, throughput, and delay are considered. The size of the network population that can be served in an RA/TDMA environment is calculated. User protocols are examined. A typical VSAT business scenario is described.

Single-Word Multiple-Bit Upsets in Static Random Access Devices

DTIC Science & Technology

1998-01-15

Transactions on Nuclear Science, NS-33, 1616- 1619,1986. Criswell, T.L., P.R. Measel , and K.L. Walin, "Single Event Upset Testing with Relativistic...Heavy Ions," IEEE Transactions on Nuclear Science, NS-31, 1559- 1561,1984. 1946 3. Criswell, T.L., D.L. Oberg, J.L. Wert, P.R. Measel , and W.E

System and method for cognitive processing for data fusion

NASA Technical Reports Server (NTRS)

Duong, Tuan A. (Inventor); Duong, Vu A. (Inventor)

2012-01-01

A system and method for cognitive processing of sensor data. A processor array receiving analog sensor data and having programmable interconnects, multiplication weights, and filters provides for adaptive learning in real-time. A static random access memory contains the programmable data for the processor array and the stored data is modified to provide for adaptive learning.

Optical monitoring of neuronal activity at high frame rate with a digital random-access multiphoton (RAMP) microscope.

PubMed

Otsu, Yo; Bormuth, Volker; Wong, Jerome; Mathieu, Benjamin; Dugué, Guillaume P; Feltz, Anne; Dieudonné, Stéphane

2008-08-30

Two-photon microscopy offers the promise of monitoring brain activity at multiple locations within intact tissue. However, serial sampling of voxels has been difficult to reconcile with millisecond timescales characteristic of neuronal activity. This is due to the conflicting constraints of scanning speed and signal amplitude. The recent use of acousto-optic deflector scanning to implement random-access multiphoton microscopy (RAMP) potentially allows to preserve long illumination dwell times while sampling multiple points-of-interest at high rates. However, the real-life abilities of RAMP microscopy regarding sensitivity and phototoxicity issues, which have so far impeded prolonged optical recordings at high frame rates, have not been assessed. Here, we describe the design, implementation and characterisation of an optimised RAMP microscope. We demonstrate the application of the microscope by monitoring calcium transients in Purkinje cells and cortical pyramidal cell dendrites and spines. We quantify the illumination constraints imposed by phototoxicity and show that stable continuous high-rate recordings can be obtained. During these recordings the fluorescence signal is large enough to detect spikes with a temporal resolution limited only by the calcium dye dynamics, improving upon previous techniques by at least an order of magnitude.

Uncoordinated MAC for Adaptive Multi Beam Directional Networks: Analysis and Evaluation

DTIC Science & Technology

2016-08-01

control (MAC) policies for emerging systems that are equipped with fully digital antenna arrays which are capable of adaptive multi-beam directional...Adaptive Beam- forming, Multibeam, Directional Networking, Random Access, Smart Antennas I. INTRODUCTION Fully digital beamforming antenna arrays that...are capable of adaptive multi-beam communications are quickly becoming a reality. These antenna arrays allow users to form multiple simultaneous

Unified Method for Delay Analysis of Random Multiple Access Algorithms.

DTIC Science & Technology

1985-08-01

packets in the first cell of the stack. The rules of the algorithm yield the following relation for the wi’s: n-1 n w 0= ; W =1; i i 9Q h I+ + zwI .+N...for computer communica- tions", in Proc. 1970 Fall Joint Computer Conf., AFIPS Press, vol. 37, 1970, pp. 281 -285. (15] N. D. Vvedenskaya and B. S

76 FR 73676 - Certain Dynamic Random Access Memory Devices, and Products Containing Same; Receipt of Complaint...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-29

... INTERNATIONAL TRADE COMMISSION [DN 2859] Certain Dynamic Random Access Memory Devices, and.... International Trade Commission has received a complaint entitled In Re Certain Dynamic Random Access Memory... certain dynamic random access memory devices, and products containing same. The complaint names Elpida...

75 FR 16507 - In the Matter of Certain Semiconductor Chips Having Synchronous Dynamic Random Access Memory...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-01

... Semiconductor Chips Having Synchronous Dynamic Random Access Memory Controllers and Products Containing Same... synchronous dynamic random access memory controllers and products containing same by reason of infringement of... semiconductor chips having synchronous dynamic random access memory controllers and products containing same...

Optimized scheduling technique of null subcarriers for peak power control in 3GPP LTE downlink.

PubMed

Cho, Soobum; Park, Sang Kyu

2014-01-01

Orthogonal frequency division multiple access (OFDMA) is a key multiple access technique for the long term evolution (LTE) downlink. However, high peak-to-average power ratio (PAPR) can cause the degradation of power efficiency. The well-known PAPR reduction technique, dummy sequence insertion (DSI), can be a realistic solution because of its structural simplicity. However, the large usage of subcarriers for the dummy sequences may decrease the transmitted data rate in the DSI scheme. In this paper, a novel DSI scheme is applied to the LTE system. Firstly, we obtain the null subcarriers in single-input single-output (SISO) and multiple-input multiple-output (MIMO) systems, respectively; then, optimized dummy sequences are inserted into the obtained null subcarrier. Simulation results show that Walsh-Hadamard transform (WHT) sequence is the best for the dummy sequence and the ratio of 16 to 20 for the WHT and randomly generated sequences has the maximum PAPR reduction performance. The number of near optimal iteration is derived to prevent exhausted iterations. It is also shown that there is no bit error rate (BER) degradation with the proposed technique in LTE downlink system.

Optimized Scheduling Technique of Null Subcarriers for Peak Power Control in 3GPP LTE Downlink

PubMed Central

Park, Sang Kyu

2014-01-01

Orthogonal frequency division multiple access (OFDMA) is a key multiple access technique for the long term evolution (LTE) downlink. However, high peak-to-average power ratio (PAPR) can cause the degradation of power efficiency. The well-known PAPR reduction technique, dummy sequence insertion (DSI), can be a realistic solution because of its structural simplicity. However, the large usage of subcarriers for the dummy sequences may decrease the transmitted data rate in the DSI scheme. In this paper, a novel DSI scheme is applied to the LTE system. Firstly, we obtain the null subcarriers in single-input single-output (SISO) and multiple-input multiple-output (MIMO) systems, respectively; then, optimized dummy sequences are inserted into the obtained null subcarrier. Simulation results show that Walsh-Hadamard transform (WHT) sequence is the best for the dummy sequence and the ratio of 16 to 20 for the WHT and randomly generated sequences has the maximum PAPR reduction performance. The number of near optimal iteration is derived to prevent exhausted iterations. It is also shown that there is no bit error rate (BER) degradation with the proposed technique in LTE downlink system. PMID:24883376

76 FR 80964 - Certain Dynamic Random Access Memory Devices, and Products Containing Same; Institution of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-27

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-821] Certain Dynamic Random Access Memory... importation, and the sale within the United States after importation of certain dynamic random access memory... certain dynamic random access memory devices, and products containing same that infringe one or more of...

Achievable Rate Estimation of IEEE 802.11ad Visual Big-Data Uplink Access in Cloud-Enabled Surveillance Applications.

PubMed

Kim, Joongheon; Kim, Jong-Kook

2016-01-01

This paper addresses the computation procedures for estimating the impact of interference in 60 GHz IEEE 802.11ad uplink access in order to construct visual big-data database from randomly deployed surveillance camera sensing devices. The acquired large-scale massive visual information from surveillance camera devices will be used for organizing big-data database, i.e., this estimation is essential for constructing centralized cloud-enabled surveillance database. This performance estimation study captures interference impacts on the target cloud access points from multiple interference components generated by the 60 GHz wireless transmissions from nearby surveillance camera devices to their associated cloud access points. With this uplink interference scenario, the interference impacts on the main wireless transmission from a target surveillance camera device to its associated target cloud access point with a number of settings are measured and estimated under the consideration of 60 GHz radiation characteristics and antenna radiation pattern models.

A floating-point/multiple-precision processor for airborne applications

NASA Technical Reports Server (NTRS)

Yee, R.

1982-01-01

A compact input output (I/O) numerical processor capable of performing floating-point, multiple precision and other arithmetic functions at execution times which are at least 100 times faster than comparable software emulation is described. The I/O device is a microcomputer system containing a 16 bit microprocessor, a numerical coprocessor with eight 80 bit registers running at a 5 MHz clock rate, 18K random access memory (RAM) and 16K electrically programmable read only memory (EPROM). The processor acts as an intelligent slave to the host computer and can be programmed in high order languages such as FORTRAN and PL/M-86.

Evaluation of Data Retention Characteristics for Ferroelectric Random Access Memories (FRAMs)

NASA Technical Reports Server (NTRS)

Sharma, Ashok K.; Teverovsky, Alexander

2001-01-01

Data retention and fatigue characteristics of 64 Kb lead zirconate titanate (PZT)-based Ferroelectric Random Access Memories (FRAMs) microcircuits manufactured by Ramtron were examined over temperature range from -85 C to +310 C for ceramic packaged parts and from -85 C to +175 C for plastic parts, during retention periods up to several thousand hours. Intrinsic failures, which were caused by a thermal degradation of the ferroelectric cells, occurred in ceramic parts after tens or hundreds hours of aging at temperatures above 200 C. The activation energy of the retention test failures was 1.05 eV and the extrapolated mean-time-to-failure (MTTF) at room temperature was estimated to be more than 280 years. Multiple write-read cycling (up to 3x10(exp 7)) during the fatigue testing of plastic and ceramic parts did not result in any parametric or functional failures. However, operational currents linearly decreased with the logarithm of number of cycles thus indicating fatigue process in PZT films. Plastic parts, that had more recent date code as compared to ceramic parts, appeared to be using die with improved process technology and showed significantly smaller changes in operational currents and data access times.

THREE-DIMENSIONAL RANDOM ACCESS MULTIPHOTON MICROSCOPY FOR FAST FUNCTIONAL IMAGING OF NEURONAL ACTIVITY

PubMed Central

Reddy, Gaddum Duemani; Kelleher, Keith; Fink, Rudy; Saggau, Peter

2009-01-01

The dynamic ability of neuronal dendrites to shape and integrate synaptic responses is the hallmark of information processing in the brain. Effectively studying this phenomenon requires concurrent measurements at multiple sites on live neurons. Significant progress has been made by optical imaging systems which combine confocal and multiphoton microscopy with inertia-free laser scanning. However, all systems developed to date restrict fast imaging to two dimensions. This severely limits the extent to which neurons can be studied, since they represent complex three-dimensional (3D) structures. Here we present a novel imaging system that utilizes a unique arrangement of acousto-optic deflectors to steer a focused ultra-fast laser beam to arbitrary locations in 3D space without moving the objective lens. As we demonstrate, this highly versatile random-access multiphoton microscope supports functional imaging of complex 3D cellular structures such as neuronal dendrites or neural populations at acquisition rates on the order of tens of kilohertz. PMID:18432198

Dynamic-load-enabled ultra-low power multiple-state RRAM devices.

PubMed

Yang, Xiang; Chen, I-Wei

2012-01-01

Bipolar resistance-switching materials allowing intermediate states of wide-varying resistance values hold the potential of drastically reduced power for non-volatile memory. To exploit this potential, we have introduced into a nanometallic resistance-random-access-memory (RRAM) device an asymmetric dynamic load, which can reliably lower switching power by orders of magnitude. The dynamic load is highly resistive during on-switching allowing access to the highly resistive intermediate states; during off-switching the load vanishes to enable switching at low voltage. This approach is entirely scalable and applicable to other bipolar RRAM with intermediate states. The projected power is 12 nW for a 100 × 100 nm(2) device and 500 pW for a 10 × 10 nm(2) device. The dynamic range of the load can be increased to allow power to be further decreased by taking advantage of the exponential decay of wave-function in a newly discovered nanometallic random material, reaching possibly 1 pW for a 10×10 nm(2) nanometallic RRAM device.

The Random Telegraph Signal Behavior of Intermittently Stuck Bits in SDRAMs

NASA Astrophysics Data System (ADS)

Chugg, Andrew Michael; Burnell, Andrew J.; Duncan, Peter H.; Parker, Sarah; Ward, Jonathan J.

2009-12-01

This paper reports behavior analogous to the Random Telegraph Signal (RTS) seen in the leakage currents from radiation induced hot pixels in Charge Coupled Devices (CCDs), but in the context of stuck bits in Synchronous Dynamic Random Access Memories (SDRAMs). Our analysis suggests that pseudo-random sticking and unsticking of the SDRAM bits is due to thermally induced fluctuations in leakage current through displacement damage complexes in depletion regions that were created by high-energy neutron and proton interactions. It is shown that the number of observed stuck bits increases exponentially with temperature, due to the general increase in the leakage currents through the damage centers with temperature. Nevertheless, some stuck bits are seen to pseudo-randomly stick and unstick in the context of a continuously rising trend of temperature, thus demonstrating that their damage centers can exist in multiple widely spaced, discrete levels of leakage current, which is highly consistent with RTS. This implies that these intermittently stuck bits (ISBs) are a displacement damage phenomenon and are unrelated to microdose issues, which is confirmed by the observation that they also occur in unbiased irradiation. Finally, we note that observed variations in the periodicity of the sticking and unsticking behavior on several timescales is most readily explained by multiple leakage current pathways through displacement damage complexes spontaneously and independently opening and closing under the influence of thermal vibrations.

Analysis of space telescope data collection system

NASA Technical Reports Server (NTRS)

Ingels, F. M.; Schoggen, W. O.

1982-01-01

An analysis of the expected performance for the Multiple Access (MA) system is provided. The analysis covers the expected bit error rate performance, the effects of synchronization loss, the problem of self-interference, and the problem of phase ambiguity. The problem of false acceptance of a command word due to data inversion is discussed. A mathematical determination of the probability of accepting an erroneous command word due to a data inversion is presented. The problem is examined for three cases: (1) a data inversion only, (2) a data inversion and a random error within the same command word, and a block (up to 256 48-bit words) containing both a data inversion and a random error.

An Adaptive OFDMA-Based MAC Protocol for Underwater Acoustic Wireless Sensor Networks

PubMed Central

Khalil, Issa M.; Gadallah, Yasser; Hayajneh, Mohammad; Khreishah, Abdallah

2012-01-01

Underwater acoustic wireless sensor networks (UAWSNs) have many applications across various civilian and military domains. However, they suffer from the limited available bandwidth of acoustic signals and harsh underwater conditions. In this work, we present an Orthogonal Frequency Division Multiple Access (OFDMA)-based Media Access Control (MAC) protocol that is configurable to suit the operating requirements of the underwater sensor network. The protocol has three modes of operation, namely random, equal opportunity and energy-conscious modes of operation. Our MAC design approach exploits the multi-path characteristics of a fading acoustic channel to convert it into parallel independent acoustic sub-channels that undergo flat fading. Communication between node pairs within the network is done using subsets of these sub-channels, depending on the configurations of the active mode of operation. Thus, the available limited bandwidth gets fully utilized while completely avoiding interference. We derive the mathematical model for optimal power loading and subcarrier selection, which is used as basis for all modes of operation of the protocol. We also conduct many simulation experiments to evaluate and compare our protocol with other Code Division Multiple Access (CDMA)-based MAC protocols. PMID:23012517

An adaptive OFDMA-based MAC protocol for underwater acoustic wireless sensor networks.

PubMed

Khalil, Issa M; Gadallah, Yasser; Hayajneh, Mohammad; Khreishah, Abdallah

2012-01-01

Underwater acoustic wireless sensor networks (UAWSNs) have many applications across various civilian and military domains. However, they suffer from the limited available bandwidth of acoustic signals and harsh underwater conditions. In this work, we present an Orthogonal Frequency Division Multiple Access (OFDMA)-based Media Access Control (MAC) protocol that is configurable to suit the operating requirements of the underwater sensor network. The protocol has three modes of operation, namely random, equal opportunity and energy-conscious modes of operation. Our MAC design approach exploits the multi-path characteristics of a fading acoustic channel to convert it into parallel independent acoustic sub-channels that undergo flat fading. Communication between node pairs within the network is done using subsets of these sub-channels, depending on the configurations of the active mode of operation. Thus, the available limited bandwidth gets fully utilized while completely avoiding interference. We derive the mathematical model for optimal power loading and subcarrier selection, which is used as basis for all modes of operation of the protocol. We also conduct many simulation experiments to evaluate and compare our protocol with other Code Division Multiple Access (CDMA)-based MAC protocols.

Calculating with light using a chip-scale all-optical abacus.

PubMed

Feldmann, J; Stegmaier, M; Gruhler, N; Ríos, C; Bhaskaran, H; Wright, C D; Pernice, W H P

2017-11-02

Machines that simultaneously process and store multistate data at one and the same location can provide a new class of fast, powerful and efficient general-purpose computers. We demonstrate the central element of an all-optical calculator, a photonic abacus, which provides multistate compute-and-store operation by integrating functional phase-change materials with nanophotonic chips. With picosecond optical pulses we perform the fundamental arithmetic operations of addition, subtraction, multiplication, and division, including a carryover into multiple cells. This basic processing unit is embedded into a scalable phase-change photonic network and addressed optically through a two-pulse random access scheme. Our framework provides first steps towards light-based non-von Neumann arithmetic.

Implementation of a Cross-Layer Sensing Medium-Access Control Scheme.

PubMed

Su, Yishan; Fu, Xiaomei; Han, Guangyao; Xu, Naishen; Jin, Zhigang

2017-04-10

In this paper, compressed sensing (CS) theory is utilized in a medium-access control (MAC) scheme for wireless sensor networks (WSNs). We propose a new, cross-layer compressed sensing medium-access control (CL CS-MAC) scheme, combining the physical layer and data link layer, where the wireless transmission in physical layer is considered as a compress process of requested packets in a data link layer according to compressed sensing (CS) theory. We first introduced using compressive complex requests to identify the exact active sensor nodes, which makes the scheme more efficient. Moreover, because the reconstruction process is executed in a complex field of a physical layer, where no bit and frame synchronizations are needed, the asynchronous and random requests scheme can be implemented without synchronization payload. We set up a testbed based on software-defined radio (SDR) to implement the proposed CL CS-MAC scheme practically and to demonstrate the validation. For large-scale WSNs, the simulation results show that the proposed CL CS-MAC scheme provides higher throughput and robustness than the carrier sense multiple access (CSMA) and compressed sensing medium-access control (CS-MAC) schemes.

78 FR 35645 - Certain Static Random Access Memories and Products Containing Same; Commission Determination...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-13

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-792] Certain Static Random Access Memories and Products Containing Same; Commission Determination Affirming a Final Initial Determination..., and the sale within the United States after importation of certain static random access memories and...

Challenges in randomized controlled trials and emerging multiple sclerosis therapeutics.

PubMed

Huang, DeRen

2015-12-01

The remarkable global development of disease-modifying therapies (DMTs) specific for multiple sclerosis (MS) has significantly reduced the frequency of relapse, slowed the progression of disability, and improved the quality of life in patients with MS. With increasing numbers of approved DMTs, neurologists in North America and Europe are able to present multiple treatment options to their patients to achieve a better therapeutic outcome, and in many cases, no evidence of disease activity. MS patients have improved accessibility to various DMTs at no or minimal out-of-pocket cost. The ethical guidelines defined by the Edinburgh revision of the Declaration of Helsinki strongly discourage the use of placebo control groups in modern MS clinical trials. The use of an active comparator control group increases the number of participants in each group that is essential to achieve statistical significance, thus further increasing the difficulty of completing randomized controlled trials (RCTs) for the development of new MS therapies. There is evidence of a high prevalence of MS and a large number of patients in Asia. The belief of the existence of Asian types of MS that are distinct from Western types, and regulatory policies are among the reasons why DMTs are limited in most Asian countries. Lack of access to approved DMTs provides a good opportunity for clinical trials that are designed for the development of new MS therapies. Recently, data from RCTs have demonstrated excellent recruitment of participants and the completion of multi-nation and single-nation MS trials within this region. Recent studies using the McDonald MS diagnostic criteria carefully excluded patients with neuromyelitis optica (NMO) and NMO spectrum disorder, and demonstrated that patients with MS in Asia have clinical characteristics and treatment responses similar to those in Western countries.

Improved Writing-Conductor Designs For Magnetic Memory

NASA Technical Reports Server (NTRS)

Wu, Jiin-Chuan; Stadler, Henry L.; Katti, Romney R.

1994-01-01

Writing currents reduced to practical levels. Improved conceptual designs for writing conductors in micromagnet/Hall-effect random-access integrated-circuit memory reduces electrical current needed to magnetize micromagnet in each memory cell. Basic concept of micromagnet/Hall-effect random-access memory presented in "Magnetic Analog Random-Access Memory" (NPO-17999).

78 FR 25767 - Certain Static Random Access Memories and Products Containing Same; Commission Determination To...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-02

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-792] Certain Static Random Access Memories and Products Containing Same; Commission Determination To Review in Part a Final Initial... States after importation of certain static random access memories and products containing the same by...

Validation of optical codes based on 3D nanostructures

NASA Astrophysics Data System (ADS)

Carnicer, Artur; Javidi, Bahram

2017-05-01

Image information encoding using random phase masks produce speckle-like noise distributions when the sample is propagated in the Fresnel domain. As a result, information cannot be accessed by simple visual inspection. Phase masks can be easily implemented in practice by attaching cello-tape to the plain-text message. Conventional 2D-phase masks can be generalized to 3D by combining glass and diffusers resulting in a more complex, physical unclonable function. In this communication, we model the behavior of a 3D phase mask using a simple approach: light is propagated trough glass using the angular spectrum of plane waves whereas the diffusor is described as a random phase mask and a blurring effect on the amplitude of the propagated wave. Using different designs for the 3D phase mask and multiple samples, we demonstrate that classification is possible using the k-nearest neighbors and random forests machine learning algorithms.

Evaluating IAIMS at Yale: information access.

PubMed

Grajek, S E; Calarco, P; Frawley, S J; McKay, J; Miller, P L; Paton, J A; Roderer, N K; Sullivan, J E

1997-01-01

To evaluate use of information resources during the first year of IAIMS implementation at the Yale-New Haven Medical Center. The evaluation asked: (1) Which information resources are being used? (2) Who uses information resources? (3) Where are information resources used? (4) Are multiple sources of information being integrated? Measures included monthly usage data for resources delivered network-wide, in the Medical Library, and in the Hospital; online surveys of library workstation users; an annual survey of a random, stratified sample of Medical Center faculty, postdoctoral trainees, students, nurses, residents, and managerial and professional staff; and user comments. Eighty-three percent of the Medical Center community use networked information resources, and use of resources is increasing. Both status (faculty, student, nurse, etc.) and mission (teaching, research, patient care) affect use of individual resources. Eighty-eight percent of people use computers in more than one location, and increases in usage of traditional library resources such as MEDLINE are due to increased access from outside the Library. Both survey and usage data suggest that people are using multiple resources during the same information seeking session. Almost all of the Medical Center community is using networked information resources in more settings. It is necessary to support increased demand for information access from remote locations and to specific populations, such as nurses. People are integrating information from multiple sources, but true integration within information systems is just beginning. Other institutions are advised to incorporate pragmatic evaluation into their IAIMS activities and to share evaluation results with decision-makers.

Conductance Quantization in Resistive Random Access Memory

NASA Astrophysics Data System (ADS)

Li, Yang; Long, Shibing; Liu, Yang; Hu, Chen; Teng, Jiao; Liu, Qi; Lv, Hangbing; Suñé, Jordi; Liu, Ming

2015-10-01

The intrinsic scaling-down ability, simple metal-insulator-metal (MIM) sandwich structure, excellent performances, and complementary metal-oxide-semiconductor (CMOS) technology-compatible fabrication processes make resistive random access memory (RRAM) one of the most promising candidates for the next-generation memory. The RRAM device also exhibits rich electrical, thermal, magnetic, and optical effects, in close correlation with the abundant resistive switching (RS) materials, metal-oxide interface, and multiple RS mechanisms including the formation/rupture of nanoscale to atomic-sized conductive filament (CF) incorporated in RS layer. Conductance quantization effect has been observed in the atomic-sized CF in RRAM, which provides a good opportunity to deeply investigate the RS mechanism in mesoscopic dimension. In this review paper, the operating principles of RRAM are introduced first, followed by the summarization of the basic conductance quantization phenomenon in RRAM and the related RS mechanisms, device structures, and material system. Then, we discuss the theory and modeling of quantum transport in RRAM. Finally, we present the opportunities and challenges in quantized RRAM devices and our views on the future prospects.

Conductance Quantization in Resistive Random Access Memory.

PubMed

Li, Yang; Long, Shibing; Liu, Yang; Hu, Chen; Teng, Jiao; Liu, Qi; Lv, Hangbing; Suñé, Jordi; Liu, Ming

2015-12-01

The intrinsic scaling-down ability, simple metal-insulator-metal (MIM) sandwich structure, excellent performances, and complementary metal-oxide-semiconductor (CMOS) technology-compatible fabrication processes make resistive random access memory (RRAM) one of the most promising candidates for the next-generation memory. The RRAM device also exhibits rich electrical, thermal, magnetic, and optical effects, in close correlation with the abundant resistive switching (RS) materials, metal-oxide interface, and multiple RS mechanisms including the formation/rupture of nanoscale to atomic-sized conductive filament (CF) incorporated in RS layer. Conductance quantization effect has been observed in the atomic-sized CF in RRAM, which provides a good opportunity to deeply investigate the RS mechanism in mesoscopic dimension. In this review paper, the operating principles of RRAM are introduced first, followed by the summarization of the basic conductance quantization phenomenon in RRAM and the related RS mechanisms, device structures, and material system. Then, we discuss the theory and modeling of quantum transport in RRAM. Finally, we present the opportunities and challenges in quantized RRAM devices and our views on the future prospects.

Interventions to Improve Access to Primary Care for People Who Are Homeless: A Systematic Review

PubMed Central

2016-01-01

Background People who are homeless encounter barriers to primary care despite having greater needs for health care, on average, than people who are not homeless. We evaluated the effectiveness of interventions to improve access to primary care for people who are homeless. Methods We performed a systematic review to identify studies in English published between January 1, 1995, and July 8, 2015, comparing interventions to improve access to a primary care provider with usual care among people who are homeless. The outcome of interest was access to a primary care provider. The risk of bias in the studies was evaluated, and the quality of the evidence was assessed according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. Results From a total of 4,047 citations, we identified five eligible studies (one randomized controlled trial and four observational studies). With the exception of the randomized trial, the risk of bias was considered high in the remaining studies. In the randomized trial, people who were homeless, without serious mental illness, and who received either an outreach intervention plus clinic orientation or clinic orientation alone, had improved access to a primary care provider compared with those receiving usual care. An observational study that compared integration of primary care and other services for people who are homeless with usual care did not observe any difference in access to a primary care provider between the two groups. A small observational study showed improvement among participants with a primary care provider after receiving an intervention consisting of housing and supportive services compared with the period before the intervention. The quality of the evidence was considered moderate for both the outreach plus clinic orientation and clinic orientation alone, and low to very low for the other interventions. Despite limitations, the literature identified reports of interventions developed to overcome barriers in access to primary care in people who are homeless. The interventions studied are complex and include multiple components that are consistent with proposed dimensions of access to care (availability, affordability, and acceptability). Conclusions Our systematic review of the literature identified various types of interventions that seek to improve access to primary care by attempting to address barriers to care encountered by people who are homeless. Moderate-quality evidence indicates that orientation to clinic services (either alone or combined with outreach) improves access to a primary care provider in adults who are homeless, without serious mental illness, and living in urban centres. PMID:27099645

Interventions to Improve Access to Primary Care for People Who Are Homeless: A Systematic Review.

PubMed

2016-01-01

People who are homeless encounter barriers to primary care despite having greater needs for health care, on average, than people who are not homeless. We evaluated the effectiveness of interventions to improve access to primary care for people who are homeless. We performed a systematic review to identify studies in English published between January 1, 1995, and July 8, 2015, comparing interventions to improve access to a primary care provider with usual care among people who are homeless. The outcome of interest was access to a primary care provider. The risk of bias in the studies was evaluated, and the quality of the evidence was assessed according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. From a total of 4,047 citations, we identified five eligible studies (one randomized controlled trial and four observational studies). With the exception of the randomized trial, the risk of bias was considered high in the remaining studies. In the randomized trial, people who were homeless, without serious mental illness, and who received either an outreach intervention plus clinic orientation or clinic orientation alone, had improved access to a primary care provider compared with those receiving usual care. An observational study that compared integration of primary care and other services for people who are homeless with usual care did not observe any difference in access to a primary care provider between the two groups. A small observational study showed improvement among participants with a primary care provider after receiving an intervention consisting of housing and supportive services compared with the period before the intervention. The quality of the evidence was considered moderate for both the outreach plus clinic orientation and clinic orientation alone, and low to very low for the other interventions. Despite limitations, the literature identified reports of interventions developed to overcome barriers in access to primary care in people who are homeless. The interventions studied are complex and include multiple components that are consistent with proposed dimensions of access to care (availability, affordability, and acceptability). Our systematic review of the literature identified various types of interventions that seek to improve access to primary care by attempting to address barriers to care encountered by people who are homeless. Moderate-quality evidence indicates that orientation to clinic services (either alone or combined with outreach) improves access to a primary care provider in adults who are homeless, without serious mental illness, and living in urban centres.

76 FR 2336 - Dynamic Random Access Memory Semiconductors From the Republic of Korea: Final Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-13

... DEPARTMENT OF COMMERCE International Trade Administration [C-580-851] Dynamic Random Access Memory... administrative review of the countervailing duty order on dynamic random access memory semiconductors from the... following events have occurred since the publication of the preliminary results of this review. See Dynamic...

ATLAS, an integrated structural analysis and design system. Volume 4: Random access file catalog

NASA Technical Reports Server (NTRS)

Gray, F. P., Jr. (Editor)

1979-01-01

A complete catalog is presented for the random access files used by the ATLAS integrated structural analysis and design system. ATLAS consists of several technical computation modules which output data matrices to corresponding random access file. A description of the matrices written on these files is contained herein.

Self care programs and multiple sclerosis: physical therapeutics treatment - literature review.

PubMed

Demaille-Wlodyka, S; Donze, C; Givron, P; Gallien, P

2011-03-01

To clarify the therapeutic education program impact with multiple sclerosis patients, literature review. Highlight contents and efficacy. A non-systematic review on Medline, PubMed and Cochrane library databases from 1966 to 2010 using the following keywords: "multiple sclerosis", "self-care", "self-management" and specific symptoms keywords. Clinical trials and randomized clinical trials, as well as literature reviews published in English, French and German will be analyzed. Counseling is a part of the non-pharmacological management of chronic illnesses such as multiple sclerosis. Symptoms' diversity and the different clinical forms limit standardized programs of self-care management, applicable to patients. In the literature review, counseling programs have often low metrology. A behavior change with patients and medical staff could exist. To empower the patient, to reduce symptoms' impact and to improve treatment access are the aims of educational therapy. Therapeutic education program for multiple sclerosis patients could progress with their standardization and assessment, for each sign. To promote the educational therapy of multiple sclerosis patients, a specific training for medical staff, as specific financing are necessary. 2011 Elsevier Masson SAS. All rights reserved.

Proceedings of the Mobile Satellite System Architectures and Multiple Access Techniques Workshop

NASA Technical Reports Server (NTRS)

Dessouky, Khaled

1989-01-01

The Mobile Satellite System Architectures and Multiple Access Techniques Workshop served as a forum for the debate of system and network architecture issues. Particular emphasis was on those issues relating to the choice of multiple access technique(s) for the Mobile Satellite Service (MSS). These proceedings contain articles that expand upon the 12 presentations given in the workshop. Contrasting views on Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), and Time Division Multiple Access (TDMA)-based architectures are presented, and system issues relating to signaling, spacecraft design, and network management constraints are addressed. An overview article that summarizes the issues raised in the numerous discussion periods of the workshop is also included.

75 FR 44283 - In the Matter of Certain Dynamic Random Access Memory Semiconductors and Products Containing Same...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-28

... Random Access Memory Semiconductors and Products Containing Same, Including Memory Modules; Notice of a... importation of certain dynamic random access memory semiconductors and products containing same, including memory modules, by reason of infringement of certain claims of U.S. Patent Nos. 5,480,051; 5,422,309; 5...

Minimal invasive epicardial lead implantation: optimizing cardiac resynchronization with a new mapping device for epicardial lead placement.

PubMed

Maessen, J G; Phelps, B; Dekker, A L A J; Dijkman, B

2004-05-01

To optimize resynchronization in biventricular pacing with epicardial leads, mapping to determine the best pacing site, is a prerequisite. A port access surgical mapping technique was developed that allowed multiple pace site selection and reproducible lead evaluation and implantation. Pressure-volume loops analysis was used for real time guidance in targeting epicardial lead placement. Even the smallest changes in lead position revealed significantly different functional results. Optimizing the pacing site with this technique allowed functional improvement up to 40% versus random pace site selection.

Performance analysis of replication ALOHA for fading mobile communications channels

NASA Technical Reports Server (NTRS)

Yan, Tsun-Yee; Clare, Loren P.

1986-01-01

This paper describes an ALOHA random access protocol for fading communications channels. A two-state Markov model is used for the channel error process to account for the channel fading memory. The ALOHA protocol is modified to send multiple contiguous copies of a message at each transmission attempt. Both pure and slotted ALOHA channels are considered. The analysis is applicable to fading environments where the channel memory is short compared to the propagation delay. It is shown that smaller delay may be achieved using replications and, in noisy conditions, can also improve throughput.

Overview of Sparse Graph for Multiple Access in Future Mobile Networks

NASA Astrophysics Data System (ADS)

Lei, Jing; Li, Baoguo; Li, Erbao; Gong, Zhenghui

2017-10-01

Multiple access via sparse graph, such as low density signature (LDS) and sparse code multiple access (SCMA), is a promising technique for future wireless communications. This survey presents an overview of the developments in this burgeoning field, including transmitter structures, extrinsic information transform (EXIT) chart analysis and comparisons with existing multiple access techniques. Such technique enables multiple access under overloaded conditions to achieve a satisfactory performance. Message passing algorithm is utilized for multi-user detection in the receiver, and structures of the sparse graph are illustrated in detail. Outlooks and challenges of this technique are also presented.

TEAMS (Tele-Exercise and Multiple Sclerosis), a Tailored Telerehabilitation mHealth App: Participant-Centered Development and Usability Study

PubMed Central

Rimmer, James H; Johnson, George; Wilroy, Jereme; Young, Hui-Ju; Mehta, Tapan; Lai, Byron

2018-01-01

Background People with multiple sclerosis face varying levels of disability and symptoms, thus requiring highly trained therapists and/or exercise trainers to design personalized exercise programs. However, for people living in geographically isolated communities, access to such trained professionals can be challenging due to a number of barriers associated with cost, access to transportation, and travel distance. Generic mobile health exercise apps often fall short of what people with multiple sclerosis need to become physically active (ie, exercise content that has been adapted to accommodate a wide range of functional limitations). Objective This usability study describes the development process of the TEAMS (Tele-Exercise and Multiple Sclerosis) app, which is being used by people with multiple sclerosis in a large randomized controlled trial to engage in home-based telerehabilitation. Methods Twenty-one participants with disabilities (10 people with multiple sclerosis) were involved in the double iterative design, which included the simultaneous development of the app features and exercise content (exercise videos and articles). Framed within a user-centered design approach, the development process included 2 stages: ground-level creation (focus group followed by early stage evaluations and developments), and proof of concept through 2 usability tests. Usability (effectiveness, usefulness, and satisfaction) was evaluated using a mixed-methods approach. Results During testing of the app’s effectiveness, the second usability test resulted in an average of 1 problem per participant, a decrease of 53% compared to the initial usability test. Five themes were constructed from the qualitative data that related to app usefulness and satisfaction, namely: high perceived confidence for app usability, positive perceptions of exercise videos, viable exercise option at home, orientation and familiarity required for successful participation, and app issues. Participants acknowledged that the final app was ready to be delivered to the public after minor revisions. After including these revisions, the project team released the final app that is being used in the randomized controlled trial. Conclusions A multi-level user-centered development process resulted in the development of an inclusive exercise program for people with multiple sclerosis operated through an easy-to-use app. The promotion of exercise through self-regulated mHealth programs requires a stakeholder-driven approach to app development. This ensures that app and content match the preferences and functional abilities of the end user (ie, people with varying levels of multiple sclerosis). PMID:29798832

TEAMS (Tele-Exercise and Multiple Sclerosis), a Tailored Telerehabilitation mHealth App: Participant-Centered Development and Usability Study.

PubMed

Thirumalai, Mohanraj; Rimmer, James H; Johnson, George; Wilroy, Jereme; Young, Hui-Ju; Mehta, Tapan; Lai, Byron

2018-05-24

People with multiple sclerosis face varying levels of disability and symptoms, thus requiring highly trained therapists and/or exercise trainers to design personalized exercise programs. However, for people living in geographically isolated communities, access to such trained professionals can be challenging due to a number of barriers associated with cost, access to transportation, and travel distance. Generic mobile health exercise apps often fall short of what people with multiple sclerosis need to become physically active (ie, exercise content that has been adapted to accommodate a wide range of functional limitations). This usability study describes the development process of the TEAMS (Tele-Exercise and Multiple Sclerosis) app, which is being used by people with multiple sclerosis in a large randomized controlled trial to engage in home-based telerehabilitation. Twenty-one participants with disabilities (10 people with multiple sclerosis) were involved in the double iterative design, which included the simultaneous development of the app features and exercise content (exercise videos and articles). Framed within a user-centered design approach, the development process included 2 stages: ground-level creation (focus group followed by early stage evaluations and developments), and proof of concept through 2 usability tests. Usability (effectiveness, usefulness, and satisfaction) was evaluated using a mixed-methods approach. During testing of the app's effectiveness, the second usability test resulted in an average of 1 problem per participant, a decrease of 53% compared to the initial usability test. Five themes were constructed from the qualitative data that related to app usefulness and satisfaction, namely: high perceived confidence for app usability, positive perceptions of exercise videos, viable exercise option at home, orientation and familiarity required for successful participation, and app issues. Participants acknowledged that the final app was ready to be delivered to the public after minor revisions. After including these revisions, the project team released the final app that is being used in the randomized controlled trial. A multi-level user-centered development process resulted in the development of an inclusive exercise program for people with multiple sclerosis operated through an easy-to-use app. The promotion of exercise through self-regulated mHealth programs requires a stakeholder-driven approach to app development. This ensures that app and content match the preferences and functional abilities of the end user (ie, people with varying levels of multiple sclerosis). ©Mohanraj Thirumalai, James H Rimmer, George Johnson, Jereme Wilroy, Hui-Ju Young, Tapan Mehta, Byron Lai. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 24.05.2018.

Clustering Single-Cell Expression Data Using Random Forest Graphs.

PubMed

Pouyan, Maziyar Baran; Nourani, Mehrdad

2017-07-01

Complex tissues such as brain and bone marrow are made up of multiple cell types. As the study of biological tissue structure progresses, the role of cell-type-specific research becomes increasingly important. Novel sequencing technology such as single-cell cytometry provides researchers access to valuable biological data. Applying machine-learning techniques to these high-throughput datasets provides deep insights into the cellular landscape of the tissue where those cells are a part of. In this paper, we propose the use of random-forest-based single-cell profiling, a new machine-learning-based technique, to profile different cell types of intricate tissues using single-cell cytometry data. Our technique utilizes random forests to capture cell marker dependences and model the cellular populations using the cell network concept. This cellular network helps us discover what cell types are in the tissue. Our experimental results on public-domain datasets indicate promising performance and accuracy of our technique in extracting cell populations of complex tissues.

Hf layer thickness dependence of resistive switching characteristics of Ti/Hf/HfO2/Au resistive random access memory device

NASA Astrophysics Data System (ADS)

Nakajima, Ryo; Azuma, Atsushi; Yoshida, Hayato; Shimizu, Tomohiro; Ito, Takeshi; Shingubara, Shoso

2018-06-01

Resistive random access memory (ReRAM) devices with a HfO2 dielectric layer have been studied extensively owing to the good reproducibility of their SET/RESET switching properties. Furthermore, it was reported that a thin Hf layer next to a HfO2 layer stabilized switching properties because of the oxygen scavenging effect. In this work, we studied the Hf thickness dependence of the resistance switching characteristics of a Ti/Hf/HfO2/Au ReRAM device. It is found that the optimum Hf thickness is approximately 10 nm to obtain good reproducibility of SET/RESET voltages with a small RESET current. However, when the Hf thickness was very small (∼2 nm), the device failed after the first RESET process owing to the very large RESET current. In the case of a very thick Hf layer (∼20 nm), RESET did not occur owing to the formation of a leaky dielectric layer. We observed the occurrence of multiple resistance states in the RESET process of the device with a Hf thickness of 10 nm by increasing the RESET voltage stepwise.

Using multiple group modeling to test moderators in meta-analysis.

PubMed

Schoemann, Alexander M

2016-12-01

Meta-analysis is a popular and flexible analysis that can be fit in many modeling frameworks. Two methods of fitting meta-analyses that are growing in popularity are structural equation modeling (SEM) and multilevel modeling (MLM). By using SEM or MLM to fit a meta-analysis researchers have access to powerful techniques associated with SEM and MLM. This paper details how to use one such technique, multiple group analysis, to test categorical moderators in meta-analysis. In a multiple group meta-analysis a model is fit to each level of the moderator simultaneously. By constraining parameters across groups any model parameter can be tested for equality. Using multiple groups to test for moderators is especially relevant in random-effects meta-analysis where both the mean and the between studies variance of the effect size may be compared across groups. A simulation study and the analysis of a real data set are used to illustrate multiple group modeling with both SEM and MLM. Issues related to multiple group meta-analysis and future directions for research are discussed. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Quantum random access memory.

PubMed

Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo

2008-04-25

A random access memory (RAM) uses n bits to randomly address N=2(n) distinct memory cells. A quantum random access memory (QRAM) uses n qubits to address any quantum superposition of N memory cells. We present an architecture that exponentially reduces the requirements for a memory call: O(logN) switches need be thrown instead of the N used in conventional (classical or quantum) RAM designs. This yields a more robust QRAM algorithm, as it in general requires entanglement among exponentially less gates, and leads to an exponential decrease in the power needed for addressing. A quantum optical implementation is presented.

Comparing cluster-level dynamic treatment regimens using sequential, multiple assignment, randomized trials: Regression estimation and sample size considerations.

PubMed

NeCamp, Timothy; Kilbourne, Amy; Almirall, Daniel

2017-08-01

Cluster-level dynamic treatment regimens can be used to guide sequential treatment decision-making at the cluster level in order to improve outcomes at the individual or patient-level. In a cluster-level dynamic treatment regimen, the treatment is potentially adapted and re-adapted over time based on changes in the cluster that could be impacted by prior intervention, including aggregate measures of the individuals or patients that compose it. Cluster-randomized sequential multiple assignment randomized trials can be used to answer multiple open questions preventing scientists from developing high-quality cluster-level dynamic treatment regimens. In a cluster-randomized sequential multiple assignment randomized trial, sequential randomizations occur at the cluster level and outcomes are observed at the individual level. This manuscript makes two contributions to the design and analysis of cluster-randomized sequential multiple assignment randomized trials. First, a weighted least squares regression approach is proposed for comparing the mean of a patient-level outcome between the cluster-level dynamic treatment regimens embedded in a sequential multiple assignment randomized trial. The regression approach facilitates the use of baseline covariates which is often critical in the analysis of cluster-level trials. Second, sample size calculators are derived for two common cluster-randomized sequential multiple assignment randomized trial designs for use when the primary aim is a between-dynamic treatment regimen comparison of the mean of a continuous patient-level outcome. The methods are motivated by the Adaptive Implementation of Effective Programs Trial which is, to our knowledge, the first-ever cluster-randomized sequential multiple assignment randomized trial in psychiatry.

A novel strategy for load balancing of distributed medical applications.

PubMed

Logeswaran, Rajasvaran; Chen, Li-Choo

2012-04-01

Current trends in medicine, specifically in the electronic handling of medical applications, ranging from digital imaging, paperless hospital administration and electronic medical records, telemedicine, to computer-aided diagnosis, creates a burden on the network. Distributed Service Architectures, such as Intelligent Network (IN), Telecommunication Information Networking Architecture (TINA) and Open Service Access (OSA), are able to meet this new challenge. Distribution enables computational tasks to be spread among multiple processors; hence, performance is an important issue. This paper proposes a novel approach in load balancing, the Random Sender Initiated Algorithm, for distribution of tasks among several nodes sharing the same computational object (CO) instances in Distributed Service Architectures. Simulations illustrate that the proposed algorithm produces better network performance than the benchmark load balancing algorithms-the Random Node Selection Algorithm and the Shortest Queue Algorithm, especially under medium and heavily loaded conditions.

Universal principles governing multiple random searchers on complex networks: The logarithmic growth pattern and the harmonic law

NASA Astrophysics Data System (ADS)

Weng, Tongfeng; Zhang, Jie; Small, Michael; Harandizadeh, Bahareh; Hui, Pan

2018-03-01

We propose a unified framework to evaluate and quantify the search time of multiple random searchers traversing independently and concurrently on complex networks. We find that the intriguing behaviors of multiple random searchers are governed by two basic principles—the logarithmic growth pattern and the harmonic law. Specifically, the logarithmic growth pattern characterizes how the search time increases with the number of targets, while the harmonic law explores how the search time of multiple random searchers varies relative to that needed by individual searchers. Numerical and theoretical results demonstrate these two universal principles established across a broad range of random search processes, including generic random walks, maximal entropy random walks, intermittent strategies, and persistent random walks. Our results reveal two fundamental principles governing the search time of multiple random searchers, which are expected to facilitate investigation of diverse dynamical processes like synchronization and spreading.

75 FR 14467 - In the Matter of: Certain Dynamic Random Access Memory Semiconductors and Products Containing...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-25

... Access Memory Semiconductors and Products Containing Same, Including Memory Modules; Notice of... the sale within the United States after importation of certain dynamic random access memory semiconductors and products containing same, including memory modules, by reason of infringement of certain...

Should multiple imputation be the method of choice for handling missing data in randomized trials?

PubMed Central

Sullivan, Thomas R; White, Ian R; Salter, Amy B; Ryan, Philip; Lee, Katherine J

2016-01-01

The use of multiple imputation has increased markedly in recent years, and journal reviewers may expect to see multiple imputation used to handle missing data. However in randomized trials, where treatment group is always observed and independent of baseline covariates, other approaches may be preferable. Using data simulation we evaluated multiple imputation, performed both overall and separately by randomized group, across a range of commonly encountered scenarios. We considered both missing outcome and missing baseline data, with missing outcome data induced under missing at random mechanisms. Provided the analysis model was correctly specified, multiple imputation produced unbiased treatment effect estimates, but alternative unbiased approaches were often more efficient. When the analysis model overlooked an interaction effect involving randomized group, multiple imputation produced biased estimates of the average treatment effect when applied to missing outcome data, unless imputation was performed separately by randomized group. Based on these results, we conclude that multiple imputation should not be seen as the only acceptable way to handle missing data in randomized trials. In settings where multiple imputation is adopted, we recommend that imputation is carried out separately by randomized group. PMID:28034175

Should multiple imputation be the method of choice for handling missing data in randomized trials?

PubMed

Sullivan, Thomas R; White, Ian R; Salter, Amy B; Ryan, Philip; Lee, Katherine J

2016-01-01

The use of multiple imputation has increased markedly in recent years, and journal reviewers may expect to see multiple imputation used to handle missing data. However in randomized trials, where treatment group is always observed and independent of baseline covariates, other approaches may be preferable. Using data simulation we evaluated multiple imputation, performed both overall and separately by randomized group, across a range of commonly encountered scenarios. We considered both missing outcome and missing baseline data, with missing outcome data induced under missing at random mechanisms. Provided the analysis model was correctly specified, multiple imputation produced unbiased treatment effect estimates, but alternative unbiased approaches were often more efficient. When the analysis model overlooked an interaction effect involving randomized group, multiple imputation produced biased estimates of the average treatment effect when applied to missing outcome data, unless imputation was performed separately by randomized group. Based on these results, we conclude that multiple imputation should not be seen as the only acceptable way to handle missing data in randomized trials. In settings where multiple imputation is adopted, we recommend that imputation is carried out separately by randomized group.

A registry-based randomized trial comparing radial and femoral approaches in women undergoing percutaneous coronary intervention: the SAFE-PCI for Women (Study of Access Site for Enhancement of PCI for Women) trial.

PubMed

Rao, Sunil V; Hess, Connie N; Barham, Britt; Aberle, Laura H; Anstrom, Kevin J; Patel, Tejan B; Jorgensen, Jesse P; Mazzaferri, Ernest L; Jolly, Sanjit S; Jacobs, Alice; Newby, L Kristin; Gibson, C Michael; Kong, David F; Mehran, Roxana; Waksman, Ron; Gilchrist, Ian C; McCourt, Brian J; Messenger, John C; Peterson, Eric D; Harrington, Robert A; Krucoff, Mitchell W

2014-08-01

This study sought to determine the effect of radial access on outcomes in women undergoing percutaneous coronary intervention (PCI) using a registry-based randomized trial. Women are at increased risk of bleeding and vascular complications after PCI. The role of radial access in women is unclear. Women undergoing cardiac catheterization or PCI were randomized to radial or femoral arterial access. Data from the CathPCI Registry and trial-specific data were merged into a final study database. The primary efficacy endpoint was Bleeding Academic Research Consortium type 2, 3, or 5 bleeding or vascular complications requiring intervention. The primary feasibility endpoint was access site crossover. The primary analysis cohort was the subgroup undergoing PCI; sensitivity analyses were conducted in the total randomized population. The trial was stopped early for a lower than expected event rate. A total of 1,787 women (691 undergoing PCI) were randomized at 60 sites. There was no significant difference in the primary efficacy endpoint between radial or femoral access among women undergoing PCI (radial 1.2% vs. 2.9% femoral, odds ratio [OR]: 0.39; 95% confidence interval [CI]: 0.12 to 1.27); among women undergoing cardiac catheterization or PCI, radial access significantly reduced bleeding and vascular complications (0.6% vs. 1.7%; OR: 0.32; 95% CI: 0.12 to 0.90). Access site crossover was significantly higher among women assigned to radial access (PCI cohort: 6.1% vs. 1.7%; OR: 3.65; 95% CI: 1.45 to 9.17); total randomized cohort: (6.7% vs. 1.9%; OR: 3.70; 95% CI: 2.14 to 6.40). More women preferred radial access. In this pragmatic trial, which was terminated early, the radial approach did not significantly reduce bleeding or vascular complications in women undergoing PCI. Access site crossover occurred more often in women assigned to radial access. (SAFE-PCI for Women; NCT01406236). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Multiple access techniques and spectrum utilization of the GLOBALSTAR mobile satellite system

NASA Astrophysics Data System (ADS)

Louie, Ming; Cohen, Michel; Rouffet, Denis; Gilhousen, Klein S.

The GLOBALSTAR System is a Low Earth Orbit (LEO) satellite-based mobile communications system that is interoperable with the current and future Public Land Mobile Network (PLMN). The GLOBALSTAR System concept is based upon technological advancement in two key areas: (1) the advancement in LEO satellite technology; (2) the advancement in cellular telephone technology, including the commercial applications of Code Division Multiple Access (CDMA) technologies, and of the most recent progress in Time Division Multiple Access technologies. The GLOBALSTAR System uses elements of CDMA, Frequency Division Multiple Access (FDMA), and Time Division Multiple Access (TDMA) technology, combining with satellite Multiple Beam Antenna (MBA) technology, to arrive at one of the most efficient modulation and multiple access system ever proposed for a satellite communications system. The technology used in GLOBALSTAR exploits the following techniques in obtaining high spectral efficiency and affordable cost per channel, with minimum coordination among different systems: power control, in open and closed loops, voice activation, spot beam satellite antenna for frequency reuse, weighted satellite antenna gain, multiple satellite coverage, and handoff between satellites. The GLOBALSTAR system design will use the following frequency bands: 1610-1626.5 MHz for up-link and 2483.5-2500 MHz for down-link.

Stress in multiple sclerosis: review of new developments and future directions.

PubMed

Lovera, Jesus; Reza, Tara

2013-11-01

In the experimental autoimmune encephalitis model of multiple sclerosis, the effects of stress on disease severity depend on multiple factors, including the animal's genetics and the type of stressor. The studies in humans relating stress to the risk of developing multiple sclerosis have found discordant results. The studies looking at the association of stress with relapses show a fairly consistent association, where higher stress is associated with a higher risk of relapse. Higher stress levels also appear to increase the risk of development of gadolinium-enhancing lesions. A recent randomized trial shows that reducing stress using stress management therapy (SMT), a cognitive-behavioral therapy approach, results in a statistically significant reduction in new magnetic resonance imaging lesions. The magnitude of this effect is large and comparable to the effects of existent disease-modifying therapies, but no data exist yet proving that SMT reduces relapses or clinical progression; the effect of SMT appears to be short-lived. Additional work is needed to improve the duration of this effect and make this therapy more widely accessible.

Dynamic Resource Allocation and Access Class Barring Scheme for Delay-Sensitive Devices in Machine to Machine (M2M) Communications.

PubMed

Li, Ning; Cao, Chao; Wang, Cong

2017-06-15

Supporting simultaneous access of machine-type devices is a critical challenge in machine-to-machine (M2M) communications. In this paper, we propose an optimal scheme to dynamically adjust the Access Class Barring (ACB) factor and the number of random access channel (RACH) resources for clustered machine-to-machine (M2M) communications, in which Delay-Sensitive (DS) devices coexist with Delay-Tolerant (DT) ones. In M2M communications, since delay-sensitive devices share random access resources with delay-tolerant devices, reducing the resources consumed by delay-sensitive devices means that there will be more resources available to delay-tolerant ones. Our goal is to optimize the random access scheme, which can not only satisfy the requirements of delay-sensitive devices, but also take the communication quality of delay-tolerant ones into consideration. We discuss this problem from the perspective of delay-sensitive services by adjusting the resource allocation and ACB scheme for these devices dynamically. Simulation results show that our proposed scheme realizes good performance in satisfying the delay-sensitive services as well as increasing the utilization rate of the random access resources allocated to them.

Randomized Trial of Clitoral Vacuum Suction Versus Vibratory Stimulation in Neurogenic Female Orgasmic Dysfunction.

PubMed

Alexander, Marcalee; Bashir, Khurram; Alexander, Craig; Marson, Lesley; Rosen, Raymond

2018-02-01

To examine the safety and efficacy of using a clitoral vacuum suction device (CVSD) versus vibratory stimulation (V) to treat orgasmic dysfunction in women with multiple sclerosis (MS) or spinal cord injury (SCI). Randomized clinical trial. Two academic medical centers. Women (N=31) including 20 with MS and 11 with SCI. A 12-week trial of the use of a CVSD versus V. Female Sexual Function Inventory (FSFI) and Female Sexual Distress Scale (FSDS). Twenty-three women (18 MS, 5 SCI) completed the study including 13 of 16 randomized to CVSD and 10 of 15 randomized to V. There was a statistically significant increase in total FSFI score (P=.011), desire (P=.009), arousal (P=.009), lubrication (P=.008), orgasm (P=.012), and satisfaction (P=.049), and a significant decrease in distress as measured by FSDS (P=.020) in subjects using the CVSD. In subjects who used V, there was a statistically significant increase in the orgasm subscale of the FSFI (P=.028). Subjects using the CVSD maintained improvements 4 weeks after treatment. CVSD is safe and overall efficacious to treat female neurogenic sexual dysfunction related to MS and SCI. V is also safe and efficacious for female neurogenic orgasmic dysfunction; however, results were limited to the active treatment period. Because of ease of access and cost, clinicians can consider use of V for women with MS or SCI with orgasmic dysfunction. CVSD is recommended for women with multiple sexual dysfunctions or for whom V is ineffective. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

A pilot study of telephone cognitive-behavioural therapy for obsessive-compulsive disorder in young people.

PubMed

Turner, Cynthia; Heyman, Isobel; Futh, Annabel; Lovell, Karina

2009-07-01

Cognitive-behaviour therapy (CBT) is the recommended psychological treatment for obsessive compulsive disorder (OCD) in young people. Access to CBT may be limited by a number of factors, including lack of trained therapists, and geographic or financial factors preventing access to a specialized service. Telephone delivery of CBT represents one way of overcoming some of these accessibility issues. This pilot study describes outcomes for a telephone-based cognitive-behavioural treatment for obsessive-compulsive disorder (OCD) in young people. Ten participants, aged 13 to 17 years, and their parents received up to 16 sessions of telephone CBT (TCBT). Measures of OCD symptoms were obtained using multiple informants and a repeated measures design. Assessments were conducted at pre-treatment, post-treatment, and at 6- and 12-month follow-up. Improvements were found for OCD symptoms across all informants. Family satisfaction with treatment over the telephone was high. The findings suggest that TCBT is a clinically effective, feasible and acceptable means of service delivery that offers the potential to make CBT a more accessible treatment for young people. TCBT requires further evaluation in randomized, controlled trials to compare effectiveness with face-to-face CBT, which currently represents the usual care model.

Integrated semiconductor-magnetic random access memory system

NASA Technical Reports Server (NTRS)

Katti, Romney R. (Inventor); Blaes, Brent R. (Inventor)

2001-01-01

The present disclosure describes a non-volatile magnetic random access memory (RAM) system having a semiconductor control circuit and a magnetic array element. The integrated magnetic RAM system uses CMOS control circuit to read and write data magnetoresistively. The system provides a fast access, non-volatile, radiation hard, high density RAM for high speed computing.

75 FR 20564 - Dynamic Random Access Memory Semiconductors from the Republic of Korea: Extension of Time Limit...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-20

... DEPARTMENT OF COMMERCE International Trade Administration [C-580-851] Dynamic Random Access Memory Semiconductors from the Republic of Korea: Extension of Time Limit for Preliminary Results of Countervailing Duty... access memory semiconductors from the Republic of Korea, covering the period January 1, 2008 through...

Temperature dependent characteristics of the random telegraph noise on contact resistive random access memory

NASA Astrophysics Data System (ADS)

Chang, Liang-Shun; Lin, Chrong Jung; King, Ya-Chin

2014-01-01

The temperature dependent characteristics of the random telegraphic noise (RTN) on contact resistive random access memory (CRRAM) are studied in this work. In addition to the bi-level switching, the occurrences of the middle states in the RTN signal are investigated. Based on the unique its temperature dependent characteristics, a new temperature sensing scheme is proposed for applications in ultra-low power sensor modules.

Multiple vaccinations, health, and recall bias within UK armed forces deployed to Iraq: cohort study.

PubMed

Murphy, Dominic; Hotopf, Matthew; Wessely, Simon

2008-06-30

To assess the relation between self reported number of vaccinations received and health, and between numbers of vaccinations recorded from individuals' medical records and health. First phase of a cohort study. UK armed forces personnel. 4882 randomly selected military personnel deployed to Iraq since 2003 and a subset of 378 whose vaccination records were accessed. Psychological distress, fatigue, symptoms of post-traumatic stress disorder, health perception, and multiple physical symptoms. Personnel who reported receiving two or more vaccinations on a single day were more likely to report symptoms of fatigue (adjusted risk ratio 1.17, 95% confidence interval 1.05 to 1.30), show caseness according to the general health questionnaire (1.31, 1.13 to 1.53), and have multiple physical symptoms (1.32, 1.08 to 1.60). These associations were no longer significant when number of vaccinations recorded in individuals' medical records was used as the independent variable. Multiple vaccinations given to personnel in the UK armed forces in preparation for deployment to Iraq are not associated with adverse health consequences when vaccinations are recorded objectively from medical records. Adverse health consequences associated with self reported multiple vaccinations could be explained by recall bias.

Effectiveness of sublingual nitroglycerin before puncture compared with conventional intra-carterial nitroglycerin in transradial procedures: a randomized trial.

PubMed

Turan, Burak; Daşlı, Tolga; Erkol, Ayhan; Erden, İsmail

2015-01-01

Sublingual (SL) nitroglycerin administered before radial artery puncture can improve cannulation success and decrease the incidence of radial artery spasm (RAS) compared with intra-arterial (IA) nitroglycerin in transradial procedures. Patients undergoing diagnostic transradial angiography were randomized to IA (200 mcg) or SL (400 mcg) nitroglycerin. Primary endpoints were puncture time and puncture attempts. Secondary endpoint was the incidence of RAS. Total of 101 participants (mean age 60±11years, 53% male) were randomized (51 in IA and 50 in SL groups). Puncture time (50 [36-75] vs 50 [35-90] sec), puncture attempts (1.18±0.48 vs 1.20±0.49), multiple punctures (13.7 vs 16.0%) and RAS (19.6 vs 24.0%) were not statistically different between IA vs SL groups respectively. A composite endpoint of all adverse events related to transradial angiography (multiple punctures, RAS, access site crossover, hypotension/bradycardia associated with nitroglycerin and radial artery occlusion) was very similar in IA vs SL groups (39 vs 40%, respectively). However puncture time was significantly longer with SL nitroglycerin in patients <1.65m height (47 [36-66] vs 63 [41-110] sec, p=0.042). Multiple punctures seemed higher with SL nitroglycerin in patients with diabetes (0 vs 30%, p=0.028) or in patients <1.65m height (7.4 vs 25%, p=0.085). Likewise, RAS with SL nitroglycerin seemed more frequent in smokers compared to IA nitroglycerin (0 vs 27%, p=0.089). SL nitroglycerin was not different from IA nitroglycerin in terms of efficiency and safety in overall study population. However it may be inferior to IA nitroglycerin in certain subgroups (shorter individuals, diabetics and smokers). Copyright © 2015 Elsevier Inc. All rights reserved.

Trellis Tone Modulation Multiple-Access for Peer Discovery in D2D Networks

PubMed Central

Lim, Chiwoo; Kim, Sang-Hyo

2018-01-01

In this paper, a new non-orthogonal multiple-access scheme, trellis tone modulation multiple-access (TTMMA), is proposed for peer discovery of distributed device-to-device (D2D) communication. The range and capacity of discovery are important performance metrics in peer discovery. The proposed trellis tone modulation uses single-tone transmission and achieves a long discovery range due to its low Peak-to-Average Power Ratio (PAPR). The TTMMA also exploits non-orthogonal resource assignment to increase the discovery capacity. For the multi-user detection of superposed multiple-access signals, a message-passing algorithm with supplementary schemes are proposed. With TTMMA and its message-passing demodulation, approximately 1.5 times the number of devices are discovered compared to the conventional frequency division multiple-access (FDMA)-based discovery. PMID:29673167

Trellis Tone Modulation Multiple-Access for Peer Discovery in D2D Networks.

PubMed

Lim, Chiwoo; Jang, Min; Kim, Sang-Hyo

2018-04-17

In this paper, a new non-orthogonal multiple-access scheme, trellis tone modulation multiple-access (TTMMA), is proposed for peer discovery of distributed device-to-device (D2D) communication. The range and capacity of discovery are important performance metrics in peer discovery. The proposed trellis tone modulation uses single-tone transmission and achieves a long discovery range due to its low Peak-to-Average Power Ratio (PAPR). The TTMMA also exploits non-orthogonal resource assignment to increase the discovery capacity. For the multi-user detection of superposed multiple-access signals, a message-passing algorithm with supplementary schemes are proposed. With TTMMA and its message-passing demodulation, approximately 1.5 times the number of devices are discovered compared to the conventional frequency division multiple-access (FDMA)-based discovery.

76 FR 55417 - In the Matter of Certain Dynamic Random Access Memory and Nand Flash Memory Devices and Products...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-07

... Access Memory and Nand Flash Memory Devices and Products Containing Same; Notice of Institution of... importation, and the sale within the United States after importation of certain dynamic random access memory and NAND flash memory devices and products containing same by reason of infringement of certain claims...

Reference-free error estimation for multiple measurement methods.

PubMed

Madan, Hennadii; Pernuš, Franjo; Špiclin, Žiga

2018-01-01

We present a computational framework to select the most accurate and precise method of measurement of a certain quantity, when there is no access to the true value of the measurand. A typical use case is when several image analysis methods are applied to measure the value of a particular quantitative imaging biomarker from the same images. The accuracy of each measurement method is characterized by systematic error (bias), which is modeled as a polynomial in true values of measurand, and the precision as random error modeled with a Gaussian random variable. In contrast to previous works, the random errors are modeled jointly across all methods, thereby enabling the framework to analyze measurement methods based on similar principles, which may have correlated random errors. Furthermore, the posterior distribution of the error model parameters is estimated from samples obtained by Markov chain Monte-Carlo and analyzed to estimate the parameter values and the unknown true values of the measurand. The framework was validated on six synthetic and one clinical dataset containing measurements of total lesion load, a biomarker of neurodegenerative diseases, which was obtained with four automatic methods by analyzing brain magnetic resonance images. The estimates of bias and random error were in a good agreement with the corresponding least squares regression estimates against a reference.

Randomized Clinical Trial of the Effectiveness of a Home-Based Advanced Practice Psychiatric Nurse Intervention: Outcomes for Individuals with Serious Mental Illness and HIV

PubMed Central

Hanrahan, Nancy P.; Wu, Evan; Kelly, Deena; Aiken, Linda H.; Blank, Michael B.

2011-01-01

Individuals with serious mental illness have greater risk for contracting HIV, multiple morbidities, and die 25 years younger than the general population. This high need and high cost subgroup face unique barriers to accessing required health care in the current health care system. The effectiveness of an advanced practice nurse model of care management was assessed in a four-year random controlled trial. Results are reported in this paper. In a four-year random controlled trial, a total of 238 community-dwelling individuals with HIV and serious mental illness (SMI) were randomly assigned to an intervention group (n=128) or to a control group (n=110). Over 12 months, the intervention group received care management from advanced practice psychiatric nurse, and the control group received usual care. The intervention group showed significant improvement in depression (P=.012) and the physical component of health-related quality of life (P=.03) from baseline to 12 months. The advanced practice psychiatric nurse intervention is a model of care that holds promise for a higher quality of care and outcomes for this vulnerable population. PMID:21935499

A Randomized Controlled Trial Examination of a Remote Parenting Intervention: Engagement and Effects on Parenting Behavior and Child Abuse Potential.

PubMed

Baggett, Kathleen; Davis, Betsy; Feil, Edward; Sheeber, Lisa; Landry, Susan; Leve, Craig; Johnson, Ursula

2017-11-01

Technology advances increasingly allow for access to remotely delivered interventions designed to promote early parenting practices that protect against child maltreatment. Among low-income families, at somewhat elevated risk for child maltreatment, there is some evidence that parents do engage in and benefit from remote-coaching interventions. However, little is known about the effectiveness of such programs to engage and benefit families at high risk for child maltreatment due to multiple stressors associated with poverty. To address this limitation, we examined engagement and outcomes among mothers at heightened risk for child abuse, who were enrolled in a randomized controlled, intent-to-treat trial of an Internet adaptation of an evidence-based infant parenting intervention. We found that engagement patterns were similar between higher and lower risk groups. Moreover, an intervention dose by condition effect was found for increased positive parent behavior and reduced child abuse potential.

Multiple Mating, Paternity and Complex Fertilisation Patterns in the Chokka Squid Loligo reynaudii

PubMed Central

Naud, Marie-Jose; Sauer, Warwick H. H.; McKeown, Niall J.; Shaw, Paul W.

2016-01-01

Polyandry is widespread and influences patterns of sexual selection, with implications for sexual conflict over mating. Assessing sperm precedence patterns is a first step towards understanding sperm competition within a female and elucidating the roles of male- and female-controlled factors. In this study behavioural field data and genetic data were combined to investigate polyandry in the chokka squid Loligo reynaudii. Microsatellite DNA-based paternity analysis revealed multiple paternity to be the norm, with 79% of broods sired by at least two males. Genetic data also determined that the male who was guarding the female at the moment of sampling was a sire in 81% of the families tested, highlighting mate guarding as a successful male tactic with postcopulatory benefits linked to sperm deposition site giving privileged access to extruded egg strings. As females lay multiple eggs in capsules (egg strings) wherein their position is not altered during maturation it is possible to describe the spatial / temporal sequence of fertilisation / sperm precedence There were four different patterns of fertilisation found among the tested egg strings: 1) unique sire; 2) dominant sire, with one or more rare sires; 3) randomly mixed paternity (two or more sires); and 4) a distinct switch in paternity occurring along the egg string. The latter pattern cannot be explained by a random use of stored sperm, and suggests postcopulatory female sperm choice. Collectively the data indicate multiple levels of male- and female-controlled influences on sperm precedence, and highlights squid as interesting models to study the interplay between sexual and natural selection. PMID:26872354

An experimental distributed microprocessor implementation with a shared memory communications and control medium

NASA Technical Reports Server (NTRS)

Mejzak, R. S.

1980-01-01

The distributed processing concept is defined in terms of control primitives, variables, and structures and their use in performing a decomposed discrete Fourier transform (DET) application function. The design assumes interprocessor communications to be anonymous. In this scheme, all processors can access an entire common database by employing control primitives. Access to selected areas within the common database is random, enforced by a hardware lock, and determined by task and subtask pointers. This enables the number of processors to be varied in the configuration without any modifications to the control structure. Decompositional elements of the DFT application function in terms of tasks and subtasks are also described. The experimental hardware configuration consists of IMSAI 8080 chassis which are independent, 8 bit microcomputer units. These chassis are linked together to form a multiple processing system by means of a shared memory facility. This facility consists of hardware which provides a bus structure to enable up to six microcomputers to be interconnected. It provides polling and arbitration logic so that only one processor has access to shared memory at any one time.

Hubless satellite communications networks

NASA Technical Reports Server (NTRS)

Robinson, Peter Alan

1994-01-01

Frequency Comb Multiple Access (FCMA) is a new combined modulation and multiple access method which will allow cheap hubless Very Small Aperture Terminal (VSAT) networks to be constructed. Theoretical results show bandwidth efficiency and power efficiency improvements over other modulation and multiple access methods. Costs of the VSAT network are reduced dramatically since a hub station is not required.

Multiple access capacity trade-offs for a Ka-band personal access satellite system

NASA Technical Reports Server (NTRS)

Dessouky, Khaled; Motamedi, Masoud

1990-01-01

System capability is critical to the economic viability of a personal satellite communication system. Ka band has significant potential to support a high capacity multiple access system because of the availability of bandwidth. System design tradeoffs are performed and multiple access schemes are compared with the design goal of achieving the highest capacity and efficiency. Conclusions regarding the efficiency of the different schemes and the achievable capacities are given.

Autonomous Information Unit for Fine-Grain Data Access Control and Information Protection in a Net-Centric System

NASA Technical Reports Server (NTRS)

Chow, Edward T.; Woo, Simon S.; James, Mark; Paloulian, George K.

2012-01-01

As communication and networking technologies advance, networks will become highly complex and heterogeneous, interconnecting different network domains. There is a need to provide user authentication and data protection in order to further facilitate critical mission operations, especially in the tactical and mission-critical net-centric networking environment. The Autonomous Information Unit (AIU) technology was designed to provide the fine-grain data access and user control in a net-centric system-testing environment to meet these objectives. The AIU is a fundamental capability designed to enable fine-grain data access and user control in the cross-domain networking environments, where an AIU is composed of the mission data, metadata, and policy. An AIU provides a mechanism to establish trust among deployed AIUs based on recombining shared secrets, authentication and verify users with a username, X.509 certificate, enclave information, and classification level. AIU achieves data protection through (1) splitting data into multiple information pieces using the Shamir's secret sharing algorithm, (2) encrypting each individual information piece using military-grade AES-256 encryption, and (3) randomizing the position of the encrypted data based on the unbiased and memory efficient in-place Fisher-Yates shuffle method. Therefore, it becomes virtually impossible for attackers to compromise data since attackers need to obtain all distributed information as well as the encryption key and the random seeds to properly arrange the data. In addition, since policy can be associated with data in the AIU, different user access and data control strategies can be included. The AIU technology can greatly enhance information assurance and security management in the bandwidth-limited and ad hoc net-centric environments. In addition, AIU technology can be applicable to general complex network domains and applications where distributed user authentication and data protection are necessary. AIU achieves fine-grain data access and user control, reducing the security risk significantly, simplifying the complexity of various security operations, and providing the high information assurance across different network domains.

BCH codes for large IC random-access memory systems

NASA Technical Reports Server (NTRS)

Lin, S.; Costello, D. J., Jr.

1983-01-01

In this report some shortened BCH codes for possible applications to large IC random-access memory systems are presented. These codes are given by their parity-check matrices. Encoding and decoding of these codes are discussed.

76 FR 35238 - Notice of Receipt of Complaint; Solicitation of Comments Relating to the Public Interest

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-16

... Static Random Access Memories and Products Containing Same, DN 2816; the Commission is soliciting... importation of certain static random access memories and products containing same. The complaint names as...

Random-access technique for modular bathymetry data storage in a continental shelf wave refraction program

NASA Technical Reports Server (NTRS)

Poole, L. R.

1974-01-01

A study was conducted of an alternate method for storage and use of bathymetry data in the Langley Research Center and Virginia Institute of Marine Science mid-Atlantic continental-shelf wave-refraction computer program. The regional bathymetry array was divided into 105 indexed modules which can be read individually into memory in a nonsequential manner from a peripheral file using special random-access subroutines. In running a sample refraction case, a 75-percent decrease in program field length was achieved by using the random-access storage method in comparison with the conventional method of total regional array storage. This field-length decrease was accompanied by a comparative 5-percent increase in central processing time and a 477-percent increase in the number of operating-system calls. A comparative Langley Research Center computer system cost savings of 68 percent was achieved by using the random-access storage method.

LTE-advanced random access mechanism for M2M communication: A review

NASA Astrophysics Data System (ADS)

Mustafa, Rashid; Sarowa, Sandeep; Jaglan, Reena Rathee; Khan, Mohammad Junaid; Agrawal, Sunil

2016-03-01

Machine Type Communications (MTC) enables one or more self-sufficient machines to communicate directly with one another without human interference. MTC applications include smart grid, security, e-Health and intelligent automation system. To support huge numbers of MTC devices, one of the challenging issues is to provide a competent way for numerous access in the network and to minimize network overload. In this article, the different control mechanisms for overload random access are reviewed to avoid congestion caused by random access channel (RACH) of MTC devices. However, past and present wireless technologies have been engineered for Human-to-Human (H2H) communications, in particular, for transmission of voice. Consequently the Long Term Evolution (LTE) -Advanced is expected to play a central role in communicating Machine to Machine (M2M) and are very optimistic about H2H communications. Distinct and unique characteristics of M2M communications create new challenges from those in H2H communications. In this article, we investigate the impact of massive M2M terminals attempting random access to LTE-Advanced all at once. We discuss and review the solutions to alleviate the overload problem by Third Generation Partnership Project (3GPP). As a result, we evaluate and compare these solutions that can effectively eliminate the congestion on the random access channel for M2M communications without affecting H2H communications.

Advanced multiple access concepts in mobile satellite systems

NASA Technical Reports Server (NTRS)

Ananasso, Fulvio

1990-01-01

Some multiple access strategies for Mobile Satellite Systems (MSS) are discussed. These strategies were investigated in the context of three separate studies conducted for the International Maritime Satellite Organization (INMARSAT) and the European Space Agency (ESA). Satellite-Switched Frequency Division Multiple Access (SS-FDMA), Code Division Multiple Access (CDMA), and Frequency-Addressable Beam architectures are addressed, discussing both system and technology aspects and outlining advantages and drawbacks of either solution with associated relevant hardware issues. An attempt is made to compare the considered option from the standpoint of user terminal/space segment complexity, synchronization requirements, spectral efficiency, and interference rejection.

Method for Evaluation of Outage Probability on Random Access Channel in Mobile Communication Systems

NASA Astrophysics Data System (ADS)

Kollár, Martin

2012-05-01

In order to access the cell in all mobile communication technologies a so called random-access procedure is used. For example in GSM this is represented by sending the CHANNEL REQUEST message from Mobile Station (MS) to Base Transceiver Station (BTS) which is consequently forwarded as an CHANNEL REQUIRED message to the Base Station Controller (BSC). If the BTS decodes some noise on the Random Access Channel (RACH) as random access by mistake (so- called ‘phantom RACH') then it is a question of pure coincidence which èstablishment cause’ the BTS thinks to have recognized. A typical invalid channel access request or phantom RACH is characterized by an IMMEDIATE ASSIGNMENT procedure (assignment of an SDCCH or TCH) which is not followed by sending an ESTABLISH INDICATION from MS to BTS. In this paper a mathematical model for evaluation of the Power RACH Busy Threshold (RACHBT) in order to guaranty in advance determined outage probability on RACH is described and discussed as well. It focuses on Global System for Mobile Communications (GSM) however the obtained results can be generalized on remaining mobile technologies (ie WCDMA and LTE).

Accessibility to health services among migrant workers in the Northeast of Thailand.

PubMed

Khongthanachayopit, Suprawee; Laohasiriwong, Wongsa

2017-01-01

Background . There is an increasing trend of trans-border migration from neighboring countries to Thailand. According to human rights laws, everyone must have access to health services, even if they are from other nationalities.  However, a small minority of health personnel in Thailand discriminate against immigrant workers, as they are from a lower financial bracket. Methods . This cross-sectional study aims to determine the prevalence of accessibility to health services and factors associated with access to health services among migrant workers who work along the Northeast border of Thailand. A total of 621 legal migrant workers were randomly selected to respond to a structured questionnaire about the satisfaction of health services, using the 5As of health services: availability; accessibility; accommodation; affordability; acceptability.  Associations between independent variables and access to health services were analysed   using multiple logistic regression analysis. Results . The results indicated that the majority of these registered migrant workers were female (63.9%) with an average age of 29± 8.61 years old, and were married (54.3%). Most of the workers worked at restaurants (80%), whereas only 20% were in agricultural sectors. Only 14% (95% CI: 11-17%) of migrant workers had access to health services. The factors that were significantly associated with accessibility to health service experienced ill health during the past one year (OR = 2.48; 95%CI; 1.54-3.97; p-value<0.001) ; have been married (OR = 2.32; 95% CI: 1.40 - 3.90; p-value <0.001). Conclusions . Most of the migrant workers could not access health services. The ones who did access health services were married or ill.

Non-Orthogonal Random Access in MIMO Cognitive Radio Networks: Beamforming, Power Allocation, and Opportunistic Transmission

PubMed Central

Lin, Huifa; Shin, Won-Yong

2017-01-01

We study secondary random access in multi-input multi-output cognitive radio networks, where a slotted ALOHA-type protocol and successive interference cancellation are used. We first introduce three types of transmit beamforming performed by secondary users, where multiple antennas are used to suppress the interference at the primary base station and/or to increase the received signal power at the secondary base station. Then, we show a simple decentralized power allocation along with the equivalent single-antenna conversion. To exploit the multiuser diversity gain, an opportunistic transmission protocol is proposed, where the secondary users generating less interference are opportunistically selected, resulting in a further reduction of the interference temperature. The proposed methods are validated via computer simulations. Numerical results show that increasing the number of transmit antennas can greatly reduce the interference temperature, while increasing the number of receive antennas leads to a reduction of the total transmit power. Optimal parameter values of the opportunistic transmission protocol are examined according to three types of beamforming and different antenna configurations, in terms of maximizing the cognitive transmission capacity. All the beamforming, decentralized power allocation, and opportunistic transmission protocol are performed by the secondary users in a decentralized manner, thus resulting in an easy implementation in practice. PMID:28076402

Non-Orthogonal Random Access in MIMO Cognitive Radio Networks: Beamforming, Power Allocation, and Opportunistic Transmission.

PubMed

Lin, Huifa; Shin, Won-Yong

2017-01-01

We study secondary random access in multi-input multi-output cognitive radio networks, where a slotted ALOHA-type protocol and successive interference cancellation are used. We first introduce three types of transmit beamforming performed by secondary users, where multiple antennas are used to suppress the interference at the primary base station and/or to increase the received signal power at the secondary base station. Then, we show a simple decentralized power allocation along with the equivalent single-antenna conversion. To exploit the multiuser diversity gain, an opportunistic transmission protocol is proposed, where the secondary users generating less interference are opportunistically selected, resulting in a further reduction of the interference temperature. The proposed methods are validated via computer simulations. Numerical results show that increasing the number of transmit antennas can greatly reduce the interference temperature, while increasing the number of receive antennas leads to a reduction of the total transmit power. Optimal parameter values of the opportunistic transmission protocol are examined according to three types of beamforming and different antenna configurations, in terms of maximizing the cognitive transmission capacity. All the beamforming, decentralized power allocation, and opportunistic transmission protocol are performed by the secondary users in a decentralized manner, thus resulting in an easy implementation in practice.

Organic Ferroelectric-Based 1T1T Random Access Memory Cell Employing a Common Dielectric Layer Overcoming the Half-Selection Problem.

PubMed

Zhao, Qiang; Wang, Hanlin; Ni, Zhenjie; Liu, Jie; Zhen, Yonggang; Zhang, Xiaotao; Jiang, Lang; Li, Rongjin; Dong, Huanli; Hu, Wenping

2017-09-01

Organic electronics based on poly(vinylidenefluoride/trifluoroethylene) (P(VDF-TrFE)) dielectric is facing great challenges in flexible circuits. As one indispensable part of integrated circuits, there is an urgent demand for low-cost and easy-fabrication nonvolatile memory devices. A breakthrough is made on a novel ferroelectric random access memory cell (1T1T FeRAM cell) consisting of one selection transistor and one ferroelectric memory transistor in order to overcome the half-selection problem. Unlike complicated manufacturing using multiple dielectrics, this system simplifies 1T1T FeRAM cell fabrication using one common dielectric. To achieve this goal, a strategy for semiconductor/insulator (S/I) interface modulation is put forward and applied to nonhysteretic selection transistors with high performances for driving or addressing purposes. As a result, high hole mobility of 3.81 cm 2 V -1 s -1 (average) for 2,6-diphenylanthracene (DPA) and electron mobility of 0.124 cm 2 V -1 s -1 (average) for N,N'-1H,1H-perfluorobutyl dicyanoperylenecarboxydiimide (PDI-FCN 2 ) are obtained in selection transistors. In this work, we demonstrate this technology's potential for organic ferroelectric-based pixelated memory module fabrication. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hand washing behavior and associated factors in Vietnam based on the Multiple Indicator Cluster Survey, 2010–2011

PubMed Central

To, Kien Gia; Lee, Jong-Koo; Nam, You-Seon; Trinh, Oanh Thi Hoang; Van Do, Dung

2016-01-01

Background Handwashing is a cost-effective way of preventing communicable diseases such as respiratory and food-borne illnesses. However, handwashing rates are low in developing countries. Target 7C of the seventh Millennium Development Goals was to increase by half the proportion of people with sustainable access to safe drinking water and basic sanitation by 2015. Studies have found that better access to improved water sources and sanitation is associated with higher rates of handwashing. Objective Our goal was to describe handwashing behaviour and identify the associated factors in Vietnamese households. Design Data from 12,000 households participating in the Vietnam Multiple Indicator Cluster Survey 2011 were used. The survey used a multistage sampling method to randomly select 100 clusters and 20 households per cluster. Self-administered questionnaires were used to collect data from a household representative. Demographic variables, the presence of a specific place for handwashing, soap and water, access to improved sanitation, and access to improved water sources were tested for association with handwashing behaviour in logistic regression. Results Almost 98% of households had a specific place for handwashing, and 85% had cleansing materials and water at such a place. The prevalence of handwashing in the sample was almost 85%. Educational level, ethnicity of the household head, and household wealth were factors associated with handwashing practice (p<0.05). Those having access to an improved sanitation facility were more likely to practise handwashing [odds ratio (OR)=1.69, 95% confidence interval (CI): 1.37–2.09, p<0.001], as were those with access to improved water sources (OR=1.74, 95% CI: 1.37–2.21, p<0.001). Conclusions Households with low education, low wealth, belonging to ethnic minorities, and with low access to improved sanitation facilities and water sources should be targeted for interventions implementing handwashing practice. In addition, the availability of soap and water at handwashing sites should be increased and practical teaching programs should be deployed in order to increase handwashing rates. PMID:26950556

Web-based self-management for patients with multiple sclerosis: a practical, randomized trial.

PubMed

Miller, Deborah M; Moore, Shirley M; Fox, Robert J; Atreja, Ashish; Fu, Alex Z; Lee, Jar-Chi; Saupe, Welf; Stadtler, Maria; Chakraborty, Swati; Harris, C M; Rudick, Richard A

2011-01-01

No studies have addressed the use of electronic personal health records (e-PHRs) for self-management in complex neurological disorders. We assessed and tested an Internet-based self-management system that utilized the e-PHR and determined its impact on self-assessed well-being, clinician-assessed well-being, and healthcare utilization in patients with multiple sclerosis (MS). Subjects were randomized to usual care (a secure Web-based messaging system) or active intervention, which included secure messaging, self-monitoring, self-management of MS symptoms, and communication about upcoming clinic visits. Computers and Internet access were provided. Subjects were included if they had MS, lived within the county or region surrounding our MS center, had at least two appointments at our center in the previous 12 months, and demonstrated basic typing and computer skills. Study duration was 12 months. Of 220 subjects completing informed consent, 206 met the inclusion criteria. At the study's end, 83 subjects remained in the usual care group and 84 in the enhanced care group. Both groups used the available system components. The groups did not significantly differ on the primary endpoints or healthcare utilization. Self-management support is an emerging aspect of chronic care management. We established the feasibility of conducting a randomized, controlled trial using e-PHRs for patient self-management. We did not find that e-PHR-enabled self-management augmented multidisciplinary MS center-based care, possibly because the differences between interventions were not great enough.

Sequencing of the large dsDNA genome of Oryctes rhinoceros nudivirus using multiple displacement amplification of nanogram amounts of virus DNA.

PubMed

Wang, Yongjie; Kleespies, Regina G; Ramle, Moslim B; Jehle, Johannes A

2008-09-01

The genomic sequence analysis of many large dsDNA viruses is hampered by the lack of enough sample materials. Here, we report a whole genome amplification of the Oryctes rhinoceros nudivirus (OrNV) isolate Ma07 starting from as few as about 10 ng of purified viral DNA by application of phi29 DNA polymerase- and exonuclease-resistant random hexamer-based multiple displacement amplification (MDA) method. About 60 microg of high molecular weight DNA with fragment sizes of up to 25 kbp was amplified. A genomic DNA clone library was generated using the product DNA. After 8-fold sequencing coverage, the 127,615 bp of OrNV whole genome was sequenced successfully. The results demonstrate that the MDA-based whole genome amplification enables rapid access to genomic information from exiguous virus samples.

Analysis of practical backoff protocols for contention resolution with multiple servers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldberg, L.A.; MacKenzie, P.D.

Backoff protocols are probably the most widely used protocols for contention resolution in multiple access channels. In this paper, we analyze the stochastic behavior of backoff protocols for contention resolution among a set of clients and servers, each server being a multiple access channel that deals with contention like an Ethernet channel. We use the standard model in which each client generates requests for a given server according to a Bemoulli distribution with a specified mean. The client-server request rate of a system is the maximum over all client-server pairs (i, j) of the sum of all request rates associatedmore » with either client i or server j. Our main result is that any superlinear polynomial backoff protocol is stable for any multiple-server system with a sub-unit client-server request rate. We confirm the practical relevance of our result by demonstrating experimentally that the average waiting time of requests is very small when such a system is run with reasonably few clients and reasonably small request rates such as those that occur in actual ethernets. Our result is the first proof of stability for any backoff protocol for contention resolution with multiple servers. Our result is also the first proof that any weakly acknowledgment based protocol is stable for contention resolution with multiple servers and such high request rates. Two special cases of our result are of interest. Hastad, Leighton and Rogoff have shown that for a single-server system with a sub-unit client-server request rate any modified superlinear polynomial backoff protocol is stable. These modified backoff protocols are similar to standard backoff protocols but require more random bits to implement. The special case of our result in which there is only one server extends the result of Hastad, Leighton and Rogoff to standard (practical) backoff protocols. Finally, our result applies to dynamic routing in optical networks.« less

Exercise program for children and adolescents with leukemia and lymphoma during treatment: A comprehensive review.

PubMed

Zucchetti, Giulia; Rossi, Francesca; Chamorro Vina, Carolina; Bertorello, Nicoletta; Fagioli, Franca

2018-05-01

An exercise program (EP) during cancer treatment seems to be a valid strategy against physiological and quality-of-life impairments, but scientific evidence of benefits among pediatric patients is still limited. This review summarizes the literature focused on randomized controlled trials of EP offered to patients during leukemia and lymphoma treatment. Studies published up to June 2017 were selected from multiple databases and assessed by three independent reviewers for methodological validity. The review identified eight studies, but several types of bias have to be avoided to provide evidence-based recommendations accessible to patients, families, and professionals. © 2018 Wiley Periodicals, Inc.

Performance analysis of the ALOHA protocol with replication in a fading channel for the Mobile Satellite Experiment

NASA Technical Reports Server (NTRS)

Clare, L. P.; Yan, T.-Y.

1985-01-01

The analysis of the ALOHA random access protocol for communications channels with fading is presented. The protocol is modified to send multiple contiguous copies of a message at each transmission attempt. Both pure and slotted ALOHA channels are considered. A general two state model is used for the channel error process to account for the channel fading memory. It is shown that greater throughput and smaller delay may be achieved using repetitions. The model is applied to the analysis of the delay-throughput performance in a fading mobile communications environment. Numerical results are given for NASA's Mobile Satellite Experiment.

Microcontroller-based binary integrator for millimeter-wave radar experiments.

PubMed

Eskelinen, Pekka; Ruoskanen, Jukka; Peltonen, Jouni

2010-05-01

An easily on-site reconfigurable multiple binary integrator for millimeter radar experiments has been constructed of static random access memories, an eight bit microcontroller, and high speed video operational amplifiers. The design uses a raw comparator path and two adjustable m-out-of-n chains in a wired-OR configuration. Standard high speed memories allow the use of pulse widths below 100 ns. For eight pulse repetition intervals it gives a maximum improvement of 6.6 dB for stationary low-level target echoes. The doubled configuration enhances the capability against fluctuating targets. Because of the raw comparator path, also single return pulses of relatively high amplitude are processed.

Memory interface simulator: A computer design aid

NASA Technical Reports Server (NTRS)

Taylor, D. S.; Williams, T.; Weatherbee, J. E.

1972-01-01

Results are presented of a study conducted with a digital simulation model being used in the design of the Automatically Reconfigurable Modular Multiprocessor System (ARMMS), a candidate computer system for future manned and unmanned space missions. The model simulates the activity involved as instructions are fetched from random access memory for execution in one of the system central processing units. A series of model runs measured instruction execution time under various assumptions pertaining to the CPU's and the interface between the CPU's and RAM. Design tradeoffs are presented in the following areas: Bus widths, CPU microprogram read only memory cycle time, multiple instruction fetch, and instruction mix.

Spread-spectrum multiple access using wideband noncoherent MFSK

NASA Technical Reports Server (NTRS)

Ha, Tri T.; Pratt, Timothy; Maggenti, Mark A.

1987-01-01

Two spread-spectrum multiple access systems which use wideband M-ary frequency shift keying (FSK) (MFSK) as the primary modulation are presented. A bit error rate performance analysis is presented and system throughput is calculated for sample C band and Ku band satellite systems. Sample link analyses are included to illustrate power and adjacent satellite interference considerations in practical multiple access systems.

A spin transfer torque magnetoresistance random access memory-based high-density and ultralow-power associative memory for fully data-adaptive nearest neighbor search with current-mode similarity evaluation and time-domain minimum searching

NASA Astrophysics Data System (ADS)

Ma, Yitao; Miura, Sadahiko; Honjo, Hiroaki; Ikeda, Shoji; Hanyu, Takahiro; Ohno, Hideo; Endoh, Tetsuo

2017-04-01

A high-density nonvolatile associative memory (NV-AM) based on spin transfer torque magnetoresistive random access memory (STT-MRAM), which achieves highly concurrent and ultralow-power nearest neighbor search with full adaptivity of the template data format, has been proposed and fabricated using the 90 nm CMOS/70 nm perpendicular-magnetic-tunnel-junction hybrid process. A truly compact current-mode circuitry is developed to realize flexibly controllable and high-parallel similarity evaluation, which makes the NV-AM adaptable to any dimensionality and component-bit of template data. A compact dual-stage time-domain minimum searching circuit is also developed, which can freely extend the system for more template data by connecting multiple NM-AM cores without additional circuits for integrated processing. Both the embedded STT-MRAM module and the computing circuit modules in this NV-AM chip are synchronously power-gated to completely eliminate standby power and maximally reduce operation power by only activating the currently accessed circuit blocks. The operations of a prototype chip at 40 MHz are demonstrated by measurement. The average operation power is only 130 µW, and the circuit density is less than 11 µm2/bit. Compared with the latest conventional works in both volatile and nonvolatile approaches, more than 31.3% circuit area reductions and 99.2% power improvements are achieved, respectively. Further power performance analyses are discussed, which verify the special superiority of the proposed NV-AM in low-power and large-memory-based VLSIs.

Efficient burst image compression using H.265/HEVC

NASA Astrophysics Data System (ADS)

Roodaki-Lavasani, Hoda; Lainema, Jani

2014-02-01

New imaging use cases are emerging as more powerful camera hardware is entering consumer markets. One family of such use cases is based on capturing multiple pictures instead of just one when taking a photograph. That kind of a camera operation allows e.g. selecting the most successful shot from a sequence of images, showing what happened right before or after the shot was taken or combining the shots by computational means to improve either visible characteristics of the picture (such as dynamic range or focus) or the artistic aspects of the photo (e.g. by superimposing pictures on top of each other). Considering that photographic images are typically of high resolution and quality and the fact that these kind of image bursts can consist of at least tens of individual pictures, an efficient compression algorithm is desired. However, traditional video coding approaches fail to provide the random access properties these use cases require to achieve near-instantaneous access to the pictures in the coded sequence. That feature is critical to allow users to browse the pictures in an arbitrary order or imaging algorithms to extract desired pictures from the sequence quickly. This paper proposes coding structures that provide such random access properties while achieving coding efficiency superior to existing image coders. The results indicate that using HEVC video codec with a single reference picture fixed for the whole sequence can achieve nearly as good compression as traditional IPPP coding structures. It is also shown that the selection of the reference frame can further improve the coding efficiency.

Methods and devices for determining quality of services of storage systems

DOEpatents

Seelam, Seetharami R [Yorktown Heights, NY; Teller, Patricia J [Las Cruces, NM

2012-01-17

Methods and systems for allowing access to computer storage systems. Multiple requests from multiple applications can be received and processed efficiently to allow traffic from multiple customers to access the storage system concurrently.

Mobile multiple access study

NASA Technical Reports Server (NTRS)

1977-01-01

Multiple access techniques (FDMA, CDMA, TDMA) for the mobile user and attempts to identify the current best technique are discussed. Traffic loading is considered as well as voice and data modulation and spacecraft and system design. Emphasis is placed on developing mobile terminal cost estimates for the selected design. In addition, design examples are presented for the alternative techniques of multiple access in order to compare with the selected technique.

Garnet Random-Access Memory

NASA Technical Reports Server (NTRS)

Katti, Romney R.

1995-01-01

Random-access memory (RAM) devices of proposed type exploit magneto-optical properties of magnetic garnets exhibiting perpendicular anisotropy. Magnetic writing and optical readout used. Provides nonvolatile storage and resists damage by ionizing radiation. Because of basic architecture and pinout requirements, most likely useful as small-capacity memory devices.

Development of Curie point switching for thin film, random access, memory device

NASA Technical Reports Server (NTRS)

Lewicki, G. W.; Tchernev, D. I.

1967-01-01

Managanese bismuthide films are used in the development of a random access memory device of high packing density and nondestructive readout capability. Memory entry is by Curie point switching using a laser beam. Readout is accomplished by microoptical or micromagnetic scanning.

Design and implementation of a random neural network routing engine.

PubMed

Kocak, T; Seeber, J; Terzioglu, H

2003-01-01

Random neural network (RNN) is an analytically tractable spiked neural network model that has been implemented in software for a wide range of applications for over a decade. This paper presents the hardware implementation of the RNN model. Recently, cognitive packet networks (CPN) is proposed as an alternative packet network architecture where there is no routing table, instead the RNN based reinforcement learning is used to route packets. Particularly, we describe implementation details for the RNN based routing engine of a CPN network processor chip: the smart packet processor (SPP). The SPP is a dual port device that stores, modifies, and interprets the defining characteristics of multiple RNN models. In addition to hardware design improvements over the software implementation such as the dual access memory, output calculation step, and reduced output calculation module, this paper introduces a major modification to the reinforcement learning algorithm used in the original CPN specification such that the number of weight terms are reduced from 2n/sup 2/ to 2n. This not only yields significant memory savings, but it also simplifies the calculations for the steady state probabilities (neuron outputs in RNN). Simulations have been conducted to confirm the proper functionality for the isolated SPP design as well as for the multiple SPP's in a networked environment.

Distributed reservation-based code division multiple access

NASA Astrophysics Data System (ADS)

Wieselthier, J. E.; Ephremides, A.

1984-11-01

The use of spread spectrum signaling, motivated primarily by its antijamming capabilities in military applications, leads naturally to the use of Code Division Multiple Access (CDMA) techniques that permit the successful simultaneous transmission by a number of users over a wideband channel. In this paper we address some of the major issues that are associated with the design of multiple access protocols for spread spectrum networks. We then propose, analyze, and evaluate a distributed reservation-based multiple access protocol that does in fact exploit CDMA properties. Especially significant is the fact that no acknowledgment or feedback information from the destination is required (thus facilitating communication with a radio-silent mode), nor is any form of coordination among the users necessary.

A comparison of Percutaneous femoral access in Endovascular Repair versus Open femoral access (PiERO): study protocol for a randomized controlled trial.

PubMed

Vierhout, Bastiaan P; Saleem, Ben R; Ott, Alewijn; van Dijl, Jan Maarten; de Kempenaer, Ties D van Andringa; Pierie, Maurice E N; Bottema, Jan T; Zeebregts, Clark J

2015-09-14

Access for endovascular repair of abdominal aortic aneurysms (EVAR) is obtained through surgical cutdown or percutaneously. The only devices suitable for percutaneous closure of the 20 French arteriotomies of the common femoral artery (CFA) are the Prostar(™) and Proglide(™) devices (Abbott Vascular). Positive effects of these devices seem to consist of a lower infection rate, and shorter operation time and hospital stay. This conclusion was published in previous reports comparing techniques in patients in two different groups (cohort or randomized). Access techniques were never compared in one and the same patient; this research simplifies comparison because patient characteristics will be similar in both groups. Percutaneous access of the CFA is compared to surgical cutdown in a single patient; in EVAR surgery, access is necessary in both groins in each patient. Randomization is performed on the introduction site of the larger main device of the endoprosthesis. The contralateral device of the endoprosthesis is smaller. When we use this type of randomization, both groups will contain a similar number of main and contralateral devices. Preoperative nose cultures and perineal cultures are obtained, to compare colonization with postoperative wound cultures (in case of a surgical site infection). Furthermore, patient comfort will be considered, using VAS-scores (Visual analog scale). Punch biopsies of the groin will be harvested to retrospectively compare skin of patients who suffered a surgical site infection (SSI) to patients who did not have an SSI. The PiERO trial is a multicenter randomized controlled clinical trial designed to show the consequences of using percutaneous access in EVAR surgery and focuses on the occurrence of surgical site infections. NTR4257 10 November 2013, NL44578.042.13.

Research on an uplink carrier sense multiple access algorithm of large indoor visible light communication networks based on an optical hard core point process.

PubMed

Nan, Zhufen; Chi, Xuefen

2016-12-20

The IEEE 802.15.7 protocol suggests that it could coordinate the channel access process based on the competitive method of carrier sensing. However, the directionality of light and randomness of diffuse reflection would give rise to a serious imperfect carrier sense (ICS) problem [e.g., hidden node (HN) problem and exposed node (EN) problem], which brings great challenges in realizing the optical carrier sense multiple access (CSMA) mechanism. In this paper, the carrier sense process implemented by diffuse reflection light is modeled as the choice of independent sets. We establish an ICS model with the presence of ENs and HNs for the multi-point to multi-point visible light communication (VLC) uplink communications system. Considering the severe optical ICS problem, an optical hard core point process (OHCPP) is developed, which characterizes the optical CSMA for the indoor VLC uplink communications system. Due to the limited coverage of the transmitted optical signal, in our OHCPP, the ENs within the transmitters' carrier sense region could be retained provided that they could not corrupt the ongoing communications. Moreover, because of the directionality of both light emitting diode (LED) transmitters and receivers, theoretical analysis of the HN problem becomes difficult. In this paper, we derive the closed-form expression for approximating the outage probability and transmission capacity of VLC networks with the presence of HNs and ENs. Simulation results validate the analysis and also show the existence of an optimal physical carrier-sensing threshold that maximizes the transmission capacity for a given emission angle of LED.

Randomized comparison of operator radiation exposure comparing transradial and transfemoral approach for percutaneous coronary procedures: rationale and design of the minimizing adverse haemorrhagic events by TRansradial access site and systemic implementation of angioX - RAdiation Dose study (RAD-MATRIX).

PubMed

Sciahbasi, Alessandro; Calabrò, Paolo; Sarandrea, Alessandro; Rigattieri, Stefano; Tomassini, Francesco; Sardella, Gennaro; Zavalloni, Dennis; Cortese, Bernardo; Limbruno, Ugo; Tebaldi, Matteo; Gagnor, Andrea; Rubartelli, Paolo; Zingarelli, Antonio; Valgimigli, Marco

2014-06-01

Radiation absorbed by interventional cardiologists is a frequently under-evaluated important issue. Aim is to compare radiation dose absorbed by interventional cardiologists during percutaneous coronary procedures for acute coronary syndromes comparing transradial and transfemoral access. The randomized multicentre MATRIX (Minimizing Adverse Haemorrhagic Events by TRansradial Access Site and Systemic Implementation of angioX) trial has been designed to compare the clinical outcome of patients with acute coronary syndromes treated invasively according to the access site (transfemoral vs. transradial) and to the anticoagulant therapy (bivalirudin vs. heparin). Selected experienced interventional cardiologists involved in this study have been equipped with dedicated thermoluminescent dosimeters to evaluate the radiation dose absorbed during transfemoral or right transradial or left transradial access. For each access we evaluate the radiation dose absorbed at wrist, at thorax and at eye level. Consequently the operator is equipped with three sets (transfemoral, right transradial or left transradial access) of three different dosimeters (wrist, thorax and eye dosimeter). Primary end-point of the study is the procedural radiation dose absorbed by operators at thorax. An important secondary end-point is the procedural radiation dose absorbed by operators comparing the right or left radial approach. Patient randomization is performed according to the MATRIX protocol for the femoral or radial approach. A further randomization for the radial approach is performed to compare right and left transradial access. The RAD-MATRIX study will probably consent to clarify the radiation issue for interventional cardiologist comparing transradial and transfemoral access in the setting of acute coronary syndromes. Copyright © 2014 Elsevier Inc. All rights reserved.

Traffic handling capability of a broadband indoor wireless network using CDMA multiple access

NASA Astrophysics Data System (ADS)

Zhang, Chang G.; Hafez, H. M.; Falconer, David D.

1994-05-01

CDMA (code division multiple access) may be an attractive technique for wireless access to broadband services because of its multiple access simplicity and other appealing features. In order to investigate traffic handling capabilities of a future network providing a variety of integrated services, this paper presents a study of a broadband indoor wireless network supporting high-speed traffic using CDMA multiple access. The results are obtained through the simulation of an indoor environment and the traffic capabilities of the wireless access to broadband 155.5 MHz ATM-SONET networks using the mm-wave band. A distributed system architecture is employed and the system performance is measured in terms of call blocking probability and dropping probability. The impacts of the base station density, traffic load, average holding time, and variable traffic sources on the system performance are examined. The improvement of system performance by implementing various techniques such as handoff, admission control, power control and sectorization are also investigated.

Development of the Average Likelihood Function for Code Division Multiple Access (CDMA) Using BPSK and QPSK Symbols

DTIC Science & Technology

2015-01-01

This research has the purpose to establish a foundation for new classification and estimation of CDMA signals. Keywords: DS / CDMA signals, BPSK, QPSK...DEVELOPMENT OF THE AVERAGE LIKELIHOOD FUNCTION FOR CODE DIVISION MULTIPLE ACCESS ( CDMA ) USING BPSK AND QPSK SYMBOLS JANUARY 2015...To) OCT 2013 – OCT 2014 4. TITLE AND SUBTITLE DEVELOPMENT OF THE AVERAGE LIKELIHOOD FUNCTION FOR CODE DIVISION MULTIPLE ACCESS ( CDMA ) USING BPSK

Pulse patterning effect in optical pulse division multiplexing for flexible single wavelength multiple access optical network

NASA Astrophysics Data System (ADS)

Jung, Sun-Young; Kim, Chang-Hun; Han, Sang-Kook

2018-05-01

A demand for high spectral efficiency requires multiple access within a single wavelength, but the uplink signals are significantly degraded because of optical beat interference (OBI) in intensity modulation/direct detection system. An optical pulse division multiplexing (OPDM) technique was proposed that could effectively reduce the OBI via a simple method as long as near-orthogonality is satisfied, but the condition was strict, and thus, the number of multiplexing units was very limited. We propose pulse pattern enhanced OPDM (e-OPDM) to reduce the OBI and improve the flexibility in multiple access within a single wavelength. The performance of the e-OPDM and patterning effect are experimentally verified after 23-km single mode fiber transmission. By employing pulse patterning in OPDM, the tight requirement was relaxed by extending the optical delay dynamic range. This could support more number of access with reduced OBI, which could eventually enhance a multiple access function.

Making working memory work: The effects of extended practice on focus capacity and the processes of updating, forward access, and random access

PubMed Central

Price, John M.; Colflesh, Gregory J. H.; Cerella, John; Verhaeghen, Paul

2014-01-01

We investigated the effects of 10 hours of practice on variations of the N-Back task to investigate the processes underlying possible expansion of the focus of attention within working memory. Using subtractive logic, we showed that random access (i.e., Sternberg-like search) yielded a modest effect (a 50% increase in speed) whereas the processes of forward access (i.e., retrieval in order, as in a standard N-Back task) and updating (i.e., changing the contents of working memory) were executed about 5 times faster after extended practice. We additionally found that extended practice increased working memory capacity as measured by the size of the focus of attention for the forward-access task, but not for variations where probing was in random order. This suggests that working memory capacity may depend on the type of search process engaged, and that certain working-memory-related cognitive processes are more amenable to practice than others. PMID:24486803

Audit of patients' awareness of ophthalmic diagnoses.

PubMed

Sudesh, S; Downes, S M; McDonnell, P J

1993-09-01

Providing information to patients about their medical condition and treatment options is important in medical management. To assess patients' knowledge of their ocular disease, prognosis, and treatment a questionnaire based survey was performed. 219 patients selected by random systematic sampling during six months from patients attending general ophthalmic clinics in Selly Oak Hospital, Birmingham, were questioned and 217 questionnaires were analysed. The findings showed that patients' knowledge of their diagnosis depended on their condition: patients with common conditions such as glaucoma and cataract had a better understanding of their condition, its treatment, and prognosis compared with patients with rarer conditions such as retinal detachment or patients with multiple diagnoses. In all, 152 patients (70%) wanted more information about their condition; 49 (23%) did not (although 12 (25%) had attempted to obtain information); and 16 (7%) were undecided. In view of the few patients with a precise understanding of their ophthalmic diagnosis and prognosis and the majority's wish for access to further information, that access needs improvement and different modes of disseminating the information should be implemented.

Electrical Evaluation of RCA MWS5501D Random Access Memory, Volume 2, Appendix a

NASA Technical Reports Server (NTRS)

Klute, A.

1979-01-01

The electrical characterization and qualification test results are presented for the RCA MWS5001D random access memory. The tests included functional tests, AC and DC parametric tests, AC parametric worst-case pattern selection test, determination of worst-case transition for setup and hold times, and a series of schmoo plots. The address access time, address readout time, the data hold time, and the data setup time are some of the results surveyed.

Computer access security code system

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr. (Inventor)

1990-01-01

A security code system for controlling access to computer and computer-controlled entry situations comprises a plurality of subsets of alpha-numeric characters disposed in random order in matrices of at least two dimensions forming theoretical rectangles, cubes, etc., such that when access is desired, at least one pair of previously unused character subsets not found in the same row or column of the matrix is chosen at random and transmitted by the computer. The proper response to gain access is transmittal of subsets which complete the rectangle, and/or a parallelepiped whose opposite corners were defined by first groups of code. Once used, subsets are not used again to absolutely defeat unauthorized access by eavesdropping, and the like.

Power- and Low-Resistance-State-Dependent, Bipolar Reset-Switching Transitions in SiN-Based Resistive Random-Access Memory

NASA Astrophysics Data System (ADS)

Kim, Sungjun; Park, Byung-Gook

2016-08-01

A study on the bipolar-resistive switching of an Ni/SiN/Si-based resistive random-access memory (RRAM) device shows that the influences of the reset power and the resistance value of the low-resistance state (LRS) on the reset-switching transitions are strong. For a low LRS with a large conducting path, the sharp reset switching, which requires a high reset power (>7 mW), was observed, whereas for a high LRS with small multiple-conducting paths, the step-by-step reset switching with a low reset power (<7 mW) was observed. The attainment of higher nonlinear current-voltage ( I-V) characteristics in terms of the step-by-step reset switching is due to the steep current-increased region of the trap-controlled space charge-limited current (SCLC) model. A multilevel cell (MLC) operation, for which the reset stop voltage ( V STOP) is used in the DC sweep mode and an incremental amplitude is used in the pulse mode for the step-by-step reset switching, is demonstrated here. The results of the present study suggest that well-controlled conducting paths in a SiN-based RRAM device, which are not too strong and not too weak, offer considerable potential for the realization of low-power and high-density crossbar-array applications.

Dual operation characteristics of resistance random access memory in indium-gallium-zinc-oxide thin film transistors

NASA Astrophysics Data System (ADS)

Yang, Jyun-Bao; Chang, Ting-Chang; Huang, Jheng-Jie; Chen, Yu-Chun; Chen, Yu-Ting; Tseng, Hsueh-Chih; Chu, Ann-Kuo; Sze, Simon M.

2014-04-01

In this study, indium-gallium-zinc-oxide thin film transistors can be operated either as transistors or resistance random access memory devices. Before the forming process, current-voltage curve transfer characteristics are observed, and resistance switching characteristics are measured after a forming process. These resistance switching characteristics exhibit two behaviors, and are dominated by different mechanisms. The mode 1 resistance switching behavior is due to oxygen vacancies, while mode 2 is dominated by the formation of an oxygen-rich layer. Furthermore, an easy approach is proposed to reduce power consumption when using these resistance random access memory devices with the amorphous indium-gallium-zinc-oxide thin film transistor.

Pain medication management processes used by oncology outpatients and family caregivers part I: health systems contexts.

PubMed

Schumacher, Karen L; Plano Clark, Vicki L; West, Claudia M; Dodd, Marylin J; Rabow, Michael W; Miaskowski, Christine

2014-11-01

Oncology patients with persistent pain treated in outpatient settings and their family caregivers have significant responsibility for managing pain medications. However, little is known about their practical day-to-day experiences with pain medication management. The aim was to describe day-to-day pain medication management from the perspectives of oncology outpatients and their family caregivers who participated in a randomized clinical trial of a psychoeducational intervention called the Pro-Self(©) Plus Pain Control Program. In this article, we focus on pain medication management by patients and family caregivers in the context of multiple complex health systems. We qualitatively analyzed audio-recorded intervention sessions that included extensive dialogue between patients, family caregivers, and nurses about pain medication management during the 10-week intervention. The health systems context for pain medication management included multiple complex systems for clinical care, reimbursement, and regulation of analgesic prescriptions. Pain medication management processes particularly relevant to this context were getting prescriptions and obtaining medications. Responsibilities that fell primarily to patients and family caregivers included facilitating communication and coordination among multiple clinicians, overcoming barriers to access, and serving as a final safety checkpoint. Significant effort was required of patients and family caregivers to insure safe and effective pain medication management. Health systems issues related to access to needed analgesics, medication safety in outpatient settings, and the effort expended by oncology patients and their family caregivers require more attention in future research and health-care reform initiatives. Copyright © 2014 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Plated wire random access memories

NASA Technical Reports Server (NTRS)

Gouldin, L. D.

1975-01-01

A program was conducted to construct 4096-work by 18-bit random access, NDRO-plated wire memory units. The memory units were subjected to comprehensive functional and environmental tests at the end-item level to verify comformance with the specified requirements. A technical description of the unit is given, along with acceptance test data sheets.

Multi-component access to a commercially available weight loss program: A randomized controlled trial

USDA-ARS?s Scientific Manuscript database

This study examined weight loss between a community-based, intensive behavioral counseling program (Weight Watchers PointsPlus that included three treatment access modes and a self-help condition. A total of 292 participants were randomized to a Weight Watchers (WW; n=147) or a self-help condition (...

Complementarity between entanglement-assisted and quantum distributed random access code

NASA Astrophysics Data System (ADS)

Hameedi, Alley; Saha, Debashis; Mironowicz, Piotr; Pawłowski, Marcin; Bourennane, Mohamed

2017-05-01

Collaborative communication tasks such as random access codes (RACs) employing quantum resources have manifested great potential in enhancing information processing capabilities beyond the classical limitations. The two quantum variants of RACs, namely, quantum random access code (QRAC) and the entanglement-assisted random access code (EARAC), have demonstrated equal prowess for a number of tasks. However, there do exist specific cases where one outperforms the other. In this article, we study a family of 3 →1 distributed RACs [J. Bowles, N. Brunner, and M. Pawłowski, Phys. Rev. A 92, 022351 (2015), 10.1103/PhysRevA.92.022351] and present its general construction of both the QRAC and the EARAC. We demonstrate that, depending on the function of inputs that is sought, if QRAC achieves the maximal success probability then EARAC fails to do so and vice versa. Moreover, a tripartite Bell-type inequality associated with the EARAC variants reveals the genuine multipartite nonlocality exhibited by our protocol. We conclude with an experimental realization of the 3 →1 distributed QRAC that achieves higher success probabilities than the maximum possible with EARACs for a number of tasks.

Portable and Error-Free DNA-Based Data Storage.

PubMed

Yazdi, S M Hossein Tabatabaei; Gabrys, Ryan; Milenkovic, Olgica

2017-07-10

DNA-based data storage is an emerging nonvolatile memory technology of potentially unprecedented density, durability, and replication efficiency. The basic system implementation steps include synthesizing DNA strings that contain user information and subsequently retrieving them via high-throughput sequencing technologies. Existing architectures enable reading and writing but do not offer random-access and error-free data recovery from low-cost, portable devices, which is crucial for making the storage technology competitive with classical recorders. Here we show for the first time that a portable, random-access platform may be implemented in practice using nanopore sequencers. The novelty of our approach is to design an integrated processing pipeline that encodes data to avoid costly synthesis and sequencing errors, enables random access through addressing, and leverages efficient portable sequencing via new iterative alignment and deletion error-correcting codes. Our work represents the only known random access DNA-based data storage system that uses error-prone nanopore sequencers, while still producing error-free readouts with the highest reported information rate/density. As such, it represents a crucial step towards practical employment of DNA molecules as storage media.

Novel image encryption algorithm based on multiple-parameter discrete fractional random transform

NASA Astrophysics Data System (ADS)

Zhou, Nanrun; Dong, Taiji; Wu, Jianhua

2010-08-01

A new method of digital image encryption is presented by utilizing a new multiple-parameter discrete fractional random transform. Image encryption and decryption are performed based on the index additivity and multiple parameters of the multiple-parameter fractional random transform. The plaintext and ciphertext are respectively in the spatial domain and in the fractional domain determined by the encryption keys. The proposed algorithm can resist statistic analyses effectively. The computer simulation results show that the proposed encryption algorithm is sensitive to the multiple keys, and that it has considerable robustness, noise immunity and security.

A Pilot Randomized Controlled Trial of the ACCESS Program: A Group Intervention to Improve Social, Adaptive Functioning, Stress Coping, and Self-Determination Outcomes in Young Adults with Autism Spectrum Disorder.

PubMed

Oswald, Tasha M; Winder-Patel, Breanna; Ruder, Steven; Xing, Guibo; Stahmer, Aubyn; Solomon, Marjorie

2018-05-01

The purpose of this pilot randomized controlled trial was to investigate the acceptability and efficacy of the Acquiring Career, Coping, Executive control, Social Skills (ACCESS) Program, a group intervention tailored for young adults with autism spectrum disorder (ASD) to enhance critical skills and beliefs that promote adult functioning, including social and adaptive skills, self-determination skills, and coping self-efficacy. Forty-four adults with ASD (ages 18-38; 13 females) and their caregivers were randomly assigned to treatment or waitlist control. Compared to controls, adults in treatment significantly improved in adaptive and self-determination skills, per caregiver report, and self-reported greater belief in their ability to access social support to cope with stressors. Results provide evidence for the acceptability and efficacy of the ACCESS Program.

AVE-SESAME program for the REEDA System

NASA Technical Reports Server (NTRS)

Hickey, J. S.

1981-01-01

The REEDA system software was modified and improved to process the AVE-SESAME severe storm data. A random access file system for the AVE storm data was designed, tested, and implemented. The AVE/SESAME software was modified to incorporate the random access file input and to interface with new graphics hardware/software now available on the REEDA system. Software was developed to graphically display the AVE/SESAME data in the convention normally used by severe storm researchers. Software was converted to AVE/SESAME software systems and interfaced with existing graphics hardware/software available on the REEDA System. Software documentation was provided for existing AVE/SESAME programs underlining functional flow charts and interacting questions. All AVE/SESAME data sets in random access format was processed to allow developed software to access the entire AVE/SESAME data base. The existing software was modified to allow for processing of different AVE/SESAME data set types including satellite surface and radar data.

Crowdsourcing reproducible seizure forecasting in human and canine epilepsy

PubMed Central

Wagenaar, Joost; Abbot, Drew; Adkins, Phillip; Bosshard, Simone C.; Chen, Min; Tieng, Quang M.; He, Jialune; Muñoz-Almaraz, F. J.; Botella-Rocamora, Paloma; Pardo, Juan; Zamora-Martinez, Francisco; Hills, Michael; Wu, Wei; Korshunova, Iryna; Cukierski, Will; Vite, Charles; Patterson, Edward E.; Litt, Brian; Worrell, Gregory A.

2016-01-01

See Mormann and Andrzejak (doi:10.1093/brain/aww091) for a scientific commentary on this article.   Accurate forecasting of epileptic seizures has the potential to transform clinical epilepsy care. However, progress toward reliable seizure forecasting has been hampered by lack of open access to long duration recordings with an adequate number of seizures for investigators to rigorously compare algorithms and results. A seizure forecasting competition was conducted on kaggle.com using open access chronic ambulatory intracranial electroencephalography from five canines with naturally occurring epilepsy and two humans undergoing prolonged wide bandwidth intracranial electroencephalographic monitoring. Data were provided to participants as 10-min interictal and preictal clips, with approximately half of the 60 GB data bundle labelled (interictal/preictal) for algorithm training and half unlabelled for evaluation. The contestants developed custom algorithms and uploaded their classifications (interictal/preictal) for the unknown testing data, and a randomly selected 40% of data segments were scored and results broadcasted on a public leader board. The contest ran from August to November 2014, and 654 participants submitted 17 856 classifications of the unlabelled test data. The top performing entry scored 0.84 area under the classification curve. Following the contest, additional held-out unlabelled data clips were provided to the top 10 participants and they submitted classifications for the new unseen data. The resulting area under the classification curves were well above chance forecasting, but did show a mean 6.54 ± 2.45% (min, max: 0.30, 20.2) decline in performance. The kaggle.com model using open access data and algorithms generated reproducible research that advanced seizure forecasting. The overall performance from multiple contestants on unseen data was better than a random predictor, and demonstrates the feasibility of seizure forecasting in canine and human epilepsy. PMID:27034258

Overview of emerging nonvolatile memory technologies

PubMed Central

2014-01-01

Nonvolatile memory technologies in Si-based electronics date back to the 1990s. Ferroelectric field-effect transistor (FeFET) was one of the most promising devices replacing the conventional Flash memory facing physical scaling limitations at those times. A variant of charge storage memory referred to as Flash memory is widely used in consumer electronic products such as cell phones and music players while NAND Flash-based solid-state disks (SSDs) are increasingly displacing hard disk drives as the primary storage device in laptops, desktops, and even data centers. The integration limit of Flash memories is approaching, and many new types of memory to replace conventional Flash memories have been proposed. Emerging memory technologies promise new memories to store more data at less cost than the expensive-to-build silicon chips used by popular consumer gadgets including digital cameras, cell phones and portable music players. They are being investigated and lead to the future as potential alternatives to existing memories in future computing systems. Emerging nonvolatile memory technologies such as magnetic random-access memory (MRAM), spin-transfer torque random-access memory (STT-RAM), ferroelectric random-access memory (FeRAM), phase-change memory (PCM), and resistive random-access memory (RRAM) combine the speed of static random-access memory (SRAM), the density of dynamic random-access memory (DRAM), and the nonvolatility of Flash memory and so become very attractive as another possibility for future memory hierarchies. Many other new classes of emerging memory technologies such as transparent and plastic, three-dimensional (3-D), and quantum dot memory technologies have also gained tremendous popularity in recent years. Subsequently, not an exaggeration to say that computer memory could soon earn the ultimate commercial validation for commercial scale-up and production the cheap plastic knockoff. Therefore, this review is devoted to the rapidly developing new class of memory technologies and scaling of scientific procedures based on an investigation of recent progress in advanced Flash memory devices. PMID:25278820

Overview of emerging nonvolatile memory technologies.

PubMed

Meena, Jagan Singh; Sze, Simon Min; Chand, Umesh; Tseng, Tseung-Yuen

2014-01-01

Nonvolatile memory technologies in Si-based electronics date back to the 1990s. Ferroelectric field-effect transistor (FeFET) was one of the most promising devices replacing the conventional Flash memory facing physical scaling limitations at those times. A variant of charge storage memory referred to as Flash memory is widely used in consumer electronic products such as cell phones and music players while NAND Flash-based solid-state disks (SSDs) are increasingly displacing hard disk drives as the primary storage device in laptops, desktops, and even data centers. The integration limit of Flash memories is approaching, and many new types of memory to replace conventional Flash memories have been proposed. Emerging memory technologies promise new memories to store more data at less cost than the expensive-to-build silicon chips used by popular consumer gadgets including digital cameras, cell phones and portable music players. They are being investigated and lead to the future as potential alternatives to existing memories in future computing systems. Emerging nonvolatile memory technologies such as magnetic random-access memory (MRAM), spin-transfer torque random-access memory (STT-RAM), ferroelectric random-access memory (FeRAM), phase-change memory (PCM), and resistive random-access memory (RRAM) combine the speed of static random-access memory (SRAM), the density of dynamic random-access memory (DRAM), and the nonvolatility of Flash memory and so become very attractive as another possibility for future memory hierarchies. Many other new classes of emerging memory technologies such as transparent and plastic, three-dimensional (3-D), and quantum dot memory technologies have also gained tremendous popularity in recent years. Subsequently, not an exaggeration to say that computer memory could soon earn the ultimate commercial validation for commercial scale-up and production the cheap plastic knockoff. Therefore, this review is devoted to the rapidly developing new class of memory technologies and scaling of scientific procedures based on an investigation of recent progress in advanced Flash memory devices.

Mof-Tree: A Spatial Access Method To Manipulate Multiple Overlapping Features.

ERIC Educational Resources Information Center

Manolopoulos, Yannis; Nardelli, Enrico; Papadopoulos, Apostolos; Proietti, Guido

1997-01-01

Investigates the manipulation of large sets of two-dimensional data representing multiple overlapping features, and presents a new access method, the MOF-tree. Analyzes storage requirements and time with respect to window query operations involving multiple features. Examines both the pointer-based and pointerless MOF-tree representations.…

Cluster randomized controlled trial of a mobile market intervention to increase fruit and vegetable intake among adults in lower-income communities in North Carolina.

PubMed

Leone, Lucia A; Tripicchio, Gina L; Haynes-Maslow, Lindsey; McGuirt, Jared; Grady Smith, Jacqueline S; Armstrong-Brown, Janelle; Gizlice, Ziya; Ammerman, Alice

2018-01-05

Poorer diets and subsequent higher rates of chronic disease among lower-income individuals may be partially attributed to reduced access to fresh fruits and vegetables (F&V) and other healthy foods. Mobile markets are an increasingly popular method for providing access to F&V in underserved communities, but evaluation efforts are limited. The purpose of this study was to determine the impact of Veggie Van (VV), a mobile produce market, on F&V intake in lower-income communities using a group randomized controlled trial. VV is a mobile produce market that sells reduced-cost locally grown produce and offers nutrition and cooking education. We recruited 12 sites in lower-income communities in North Carolina (USA) to host VV, randomizing them to receive VV immediately (intervention) or after the 6-month study period (delayed intervention control). Participants at each site completed baseline and follow-up surveys including F&V intake, perceived access to fresh F&V and self-efficacy for purchasing, preparing and eating F&V. We used multiple linear regression to calculate adjusted differences in outcomes while controlling for baseline values, education and clustering within site. Among 142 participants who completed the follow-up, baseline F&V intake was 3.48 cups/day for control and 3.33 for intervention. At follow-up, adjusted change in F&V consumption was 0.95 cups/day greater for intervention participants (p = 0.005), but was attenuated to 0.51 cups per day (p = 0.11) after removing extreme values. VV customers increased their F&V consumption by 0.41 cups/day (n = 30) compared to a 0.25 cups/day decrease for 111 non-customers (p = 0.04). Intervention participants did not show significant improvements in perceived access to fresh F&V, but increased their self-efficacy for working more F&V into snacks (p = 0.02), making up a vegetable dish with what they had on hand (p = 0.03), and cooking vegetables in a way that is appealing to their family (p = 0.048). Mobile markets may help improve F&V intake in lower-income communities. Clinicaltrials.gov ID# NCT03026608 retrospectively registered January 2, 2017.

Access of children with cerebral palsy to the physical, social and attitudinal environment they need: a cross-sectional European study.

PubMed

Colver, Allan F; Dickinson, Heather O; Parkinson, Kathryn; Arnaud, Catherine; Beckung, Eva; Fauconnier, Jérôme; Marcelli, Marco; McManus, Vicki; Michelsen, Susan I; Parkes, Jackie; Thyen, Ute

2011-01-01

The UN Convention on the Rights of Persons with Disabilities requires states 'to ensure to persons with disabilities access, on an equal basis with others, to the physical environment, transportation, information and communications.' We explored whether this convention was respected for disabled children in Europe. One thousand one-hundred and seventy-four children aged 8-12 years were randomly selected from population-based registers of children with cerebral palsy in eight European regions. 743 children joined the study; one further region recruited 75 children from multiple sources. Researchers visited these 818 children and administered the European Child Environment Questionnaire, which records parents' perceptions of availability of the physical, social and attitudinal environment needed in home, school and community. Multilevel, multivariable regression related child access on these domains to their impairments and socio-demographic characteristics. Children with more impaired walking ability had less access to the physical environment, transport and social support they needed than other children. They also experienced less favourable attitudes from family and friends. However, attitudes of teachers and therapists were similar for children with all levels of impairment. The access of children, across all impairment severities, to their needed environment showed significant variation between regions (p ≤ 0.0001), some regions consistently providing better access on most or all domains. European states need to substantially improve environmental access for disabled children in order to meet their obligations under UN Conventions. In some regions, many environmental factors should and realistically could be changed. Legislation and regulation should be directed to making this happen. Local environmental planners and health and social service providers should listen carefully to parents to address mismatches between policy intentions and parental experience.

Adeno-Associated Virus Type 2 Wild-Type and Vector-Mediated Genomic Integration Profiles of Human Diploid Fibroblasts Analyzed by Third-Generation PacBio DNA Sequencing

PubMed Central

Hüser, Daniela; Gogol-Döring, Andreas; Chen, Wei

2014-01-01

ABSTRACT Genome-wide analysis of adeno-associated virus (AAV) type 2 integration in HeLa cells has shown that wild-type AAV integrates at numerous genomic sites, including AAVS1 on chromosome 19q13.42. Multiple GAGY/C repeats, resembling consensus AAV Rep-binding sites are preferred, whereas rep-deficient AAV vectors (rAAV) regularly show a random integration profile. This study is the first study to analyze wild-type AAV integration in diploid human fibroblasts. Applying high-throughput third-generation PacBio-based DNA sequencing, integration profiles of wild-type AAV and rAAV are compared side by side. Bioinformatic analysis reveals that both wild-type AAV and rAAV prefer open chromatin regions. Although genomic features of AAV integration largely reproduce previous findings, the pattern of integration hot spots differs from that described in HeLa cells before. DNase-Seq data for human fibroblasts and for HeLa cells reveal variant chromatin accessibility at preferred AAV integration hot spots that correlates with variant hot spot preferences. DNase-Seq patterns of these sites in human tissues, including liver, muscle, heart, brain, skin, and embryonic stem cells further underline variant chromatin accessibility. In summary, AAV integration is dependent on cell-type-specific, variant chromatin accessibility leading to random integration profiles for rAAV, whereas wild-type AAV integration sites cluster near GAGY/C repeats. IMPORTANCE Adeno-associated virus type 2 (AAV) is assumed to establish latency by chromosomal integration of its DNA. This is the first genome-wide analysis of wild-type AAV2 integration in diploid human cells and the first to compare wild-type to recombinant AAV vector integration side by side under identical experimental conditions. Major determinants of wild-type AAV integration represent open chromatin regions with accessible consensus AAV Rep-binding sites. The variant chromatin accessibility of different human tissues or cell types will have impact on vector targeting to be considered during gene therapy. PMID:25031342

Developing Substance Use Programming for Person-Oriented Recovery and Treatment (SUPPORT): protocol for a pilot randomized controlled trial.

PubMed

Watson, Dennis P; Ray, Bradley; Robison, Lisa; Xu, Huiping; Edwards, Rhiannon; Salyers, Michelle P; Hill, James; Shue, Sarah

2017-01-01

There is a lack of evidence-based substance use disorder treatment and services targeting returning inmates. Substance Use Programming for Person-Oriented Recovery and Treatment (SUPPORT) is a community-driven, recovery-oriented approach to substance abuse care which has the potential to address this service gap. SUPPORT is modeled after Indiana's Access to Recovery program, which was closed due to lack of federal support despite positive improvements in clients' recovery outcomes. SUPPORT builds on noted limitations of Indiana's Access to Recovery program. The ultimate goal of this project is to establish SUPPORT as an effective and scalable recovery-oriented system of care. A necessary step we must take before launching a large clinical trial is pilot testing the SUPPORT intervention. The pilot will take place at Public Advocates in Community Re-Entry (PACE), nonprofit serving individuals with felony convictions who are located in Marion County, Indiana (Indianapolis). The pilot will follow a basic parallel randomized design to compare clients receiving SUPPORT with clients receiving standard services. A total of 80 clients within 3 months of prison release will be recruited to participate and randomly assigned to one of the two intervention arms. Quantitative measures will be collected at multiple time points to understand SUPPORT's impact on recovery capital and outcomes. We will also collect qualitative data from SUPPORT clients to better understand their program and post-discharge experiences. Successful completion of this pilot will prepare us to conduct a multi-site clinical trial. The ultimate goal of this future work is to develop an evidence-based and scalable approach to treating substance use disorder among persons returning to society after incarceration. ClinicalTrials.gov (Clinical Trials ID: NCT03132753 and Protocol Number: 1511731907). Registered 28 April 2017.

Universal filtered multi-carrier system for asynchronous uplink transmission in optical access network

NASA Astrophysics Data System (ADS)

Kang, Soo-Min; Kim, Chang-Hun; Han, Sang-Kook

2016-02-01

In passive optical network (PON), orthogonal frequency division multiplexing (OFDM) has been studied actively due to its advantages such as high spectra efficiency (SE), dynamic resource allocation in time or frequency domain, and dispersion robustness. However, orthogonal frequency division multiple access (OFDMA)-PON requires tight synchronization among multiple access signals. If not, frequency orthogonality could not be maintained. Also its sidelobe causes inter-channel interference (ICI) to adjacent channel. To prevent ICI caused by high sidelobes, guard band (GB) is usually used which degrades SE. Thus, OFDMA-PON is not suitable for asynchronous uplink transmission in optical access network. In this paper, we propose intensity modulation/direct detection (IM/DD) based universal filtered multi-carrier (UFMC) PON for asynchronous multiple access. The UFMC uses subband filtering to subsets of subcarriers. Since it reduces sidelobe of each subband by applying subband filtering, it could achieve better performance compared to OFDM. For the experimental demonstration, different sample delay was applied to subbands to implement asynchronous transmission condition. As a result, time synchronization robustness of UFMC was verified in asynchronous multiple access system.

An incremental database access method for autonomous interoperable databases

NASA Technical Reports Server (NTRS)

Roussopoulos, Nicholas; Sellis, Timos

1994-01-01

We investigated a number of design and performance issues of interoperable database management systems (DBMS's). The major results of our investigation were obtained in the areas of client-server database architectures for heterogeneous DBMS's, incremental computation models, buffer management techniques, and query optimization. We finished a prototype of an advanced client-server workstation-based DBMS which allows access to multiple heterogeneous commercial DBMS's. Experiments and simulations were then run to compare its performance with the standard client-server architectures. The focus of this research was on adaptive optimization methods of heterogeneous database systems. Adaptive buffer management accounts for the random and object-oriented access methods for which no known characterization of the access patterns exists. Adaptive query optimization means that value distributions and selectives, which play the most significant role in query plan evaluation, are continuously refined to reflect the actual values as opposed to static ones that are computed off-line. Query feedback is a concept that was first introduced to the literature by our group. We employed query feedback for both adaptive buffer management and for computing value distributions and selectivities. For adaptive buffer management, we use the page faults of prior executions to achieve more 'informed' management decisions. For the estimation of the distributions of the selectivities, we use curve-fitting techniques, such as least squares and splines, for regressing on these values.

Cooperation evolution in random multiplicative environments

NASA Astrophysics Data System (ADS)

Yaari, G.; Solomon, S.

2010-02-01

Most real life systems have a random component: the multitude of endogenous and exogenous factors influencing them result in stochastic fluctuations of the parameters determining their dynamics. These empirical systems are in many cases subject to noise of multiplicative nature. The special properties of multiplicative noise as opposed to additive noise have been noticed for a long while. Even though apparently and formally the difference between free additive vs. multiplicative random walks consists in just a move from normal to log-normal distributions, in practice the implications are much more far reaching. While in an additive context the emergence and survival of cooperation requires special conditions (especially some level of reward, punishment, reciprocity), we find that in the multiplicative random context the emergence of cooperation is much more natural and effective. We study the various implications of this observation and its applications in various contexts.

Mobile critical care recovery program (m-CCRP) for acute respiratory failure survivors: study protocol for a randomized controlled trial.

PubMed

Khan, Sikandar; Biju, Ashok; Wang, Sophia; Gao, Sujuan; Irfan, Omar; Harrawood, Amanda; Martinez, Stephanie; Brewer, Emily; Perkins, Anthony; Unverzagt, Frederick W; Lasiter, Sue; Zarzaur, Ben; Rahman, Omar; Boustani, Malaz; Khan, Babar

2018-02-07

Patients admitted to intensive care units (ICU) with acute respiratory failure (ARF) face chronic complications that can impede return to normal daily function. A mobile, collaborative critical care model may enhance the recovery of ARF survivors. The Mobile Critical Care Recovery Program (m-CCRP) study is a two arm, randomized clinical trial. We will randomize 620 patients admitted to the ICU with acute respiratory failure requiring mechanical ventilation in a 1:1 ratio to one of two arms (310 patients per arm) - m-CCRP intervention versus attention control. Those in the intervention group will meet with a care coordinator after hospital discharge in predetermined intervals to aid in the recovery process. Baseline assessments and personalized goal setting will be used to develop an individualized care plan for each patient after discussion with an interdisciplinary team. The attention control arm will receive printed material and telephone reminders emphasizing mobility and management of chronic conditions. Duration of the intervention and follow-up is 12 months post-randomization. Our primary aim is to assess the efficacy of m-CCRP in improving the quality of life of ARF survivors at 12 months. Secondary aims of the study are to evaluate the efficacy of m-CCRP in improving function (cognitive, physical, and psychological) of ARF survivors and to determine the efficacy of m-CCRP in reducing acute healthcare utilization. The proposed randomized controlled trial will evaluate the efficacy of a collaborative critical care recovery program in accomplishing the Institute of Healthcare Improvement's triple aims of better health, better care, at lower cost. We have developed a collaborative critical care model to promote ARF survivors' recovery from the physical, psychological, and cognitive impacts of critical illness. In contrast to a single disease focus and clinic-based access, m-CCRP represents a comprehensive, accessible, mobile, ahead of the curve intervention, focused on the multiple aspects of the unique recovery needs of ARF survivors. NCT03053245 , clinicaltrials.gov, registered February 1, 2017.

A systematic analysis of factors localized to damaged chromatin reveals PARP-dependent recruitment of transcription factors

PubMed Central

Izhar, Lior; Adamson, Britt; Ciccia, Alberto; Lewis, Jedd; Pontano-Vaites, Laura; Leng, Yumei; Liang, Anthony C.; Westbrook, Thomas F.; Harper, J. Wade; Elledge, Stephen J.

2015-01-01

Localization to sites of DNA damage is a hallmark of DNA damage response (DDR) proteins. To identify new DDR factors, we screened epitope-tagged proteins for localization to sites of chromatin damaged by UV laser microirradiation and found >120 proteins that localize to damaged chromatin. These include the BAF tumor suppressor complex and the ALS candidate protein TAF15. TAF15 contains multiple domains that bind damaged chromatin in a PARP-dependent manner, suggesting a possible role as glue that tethers multiple PAR chains together. Many positives were transcription factors and >70% of randomly tested transcription factors localized to sites of DNA damage and approximately 90% were PARP-dependent for localization. Mutational analyses showed that localization to damaged chromatin is DNA-binding domain-dependent. By examining Hoechst staining patterns at damage sites, we see evidence of chromatin decompaction that is PARP-dependent. We propose that PARP-regulated chromatin remodeling at sites of damage allows transient accessibility of DNA-binding proteins. PMID:26004182

Low power test architecture for dynamic read destructive fault detection in SRAM

NASA Astrophysics Data System (ADS)

Takher, Vikram Singh; Choudhary, Rahul Raj

2018-06-01

Dynamic Read Destructive Fault (dRDF) is the outcome of resistive open defects in the core cells of static random-access memories (SRAMs). The sensitisation of dRDF involves either performing multiple read operations or creation of number of read equivalent stress (RES), on the core cell under test. Though the creation of RES is preferred over the performing multiple read operation on the core cell, cell dissipates more power during RES than during the read or write operation. This paper focuses on the reduction in power dissipation by optimisation of number of RESs, which are required to sensitise the dRDF during test mode of operation of SRAM. The novel pre-charge architecture has been proposed in order to reduce the power dissipation by limiting the number of RESs to an optimised number of two. The proposed low power architecture is simulated and analysed which shows reduction in power dissipation by reducing the number of RESs up to 18.18%.

Case Study: An Ethics Case Study of HIV Prevention Research on Facebook: The Just/Us Study

PubMed Central

Breslin, Lindsey T.; Wright, Erin E.; Black, Sandra R.; Levine, Deborah; Santelli, John S.

2011-01-01

Objective To consider issues related to research with youth on social networking sites online. Methods Description of the data collection process from 1,588 participants in a randomized controlled trial testing the efficacy of HIV prevention education delivered on Facebook. Using respondent-driven sampling, staff-recruited participants are encouraged to recruit up to three friends to enroll in the study. Results Researchers should (a) consider whether an online social networking site is an appropriate place to implement a research study; (b) offer opportunities to review informed consent documents at multiple times and in multiple locations throughout the study; and (c) collect data outside the social networking site and store it behind secure firewalls to ensure it will not be accessible to any person on the social networking site. Conclusions Online social networks are growing in popularity. Conducting research on social media sites requires deliberate attention to consent, confidentiality, and security. PMID:21292724

Making working memory work: the effects of extended practice on focus capacity and the processes of updating, forward access, and random access.

PubMed

Price, John M; Colflesh, Gregory J H; Cerella, John; Verhaeghen, Paul

2014-05-01

We investigated the effects of 10h of practice on variations of the N-Back task to investigate the processes underlying possible expansion of the focus of attention within working memory. Using subtractive logic, we showed that random access (i.e., Sternberg-like search) yielded a modest effect (a 50% increase in speed) whereas the processes of forward access (i.e., retrieval in order, as in a standard N-Back task) and updating (i.e., changing the contents of working memory) were executed about 5 times faster after extended practice. We additionally found that extended practice increased working memory capacity as measured by the size of the focus of attention for the forward-access task, but not for variations where probing was in random order. This suggests that working memory capacity may depend on the type of search process engaged, and that certain working-memory-related cognitive processes are more amenable to practice than others. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification of cultivars and validation of genetic relationships in Mangifera indica L. using RAPD markers.

PubMed

Schnell, R J; Ronning, C M; Knight, R J

1995-02-01

Twenty-five accessions of mango were examined for random amplified polymorphic DNA (RAPD) genetic markers with 80 10-mer random primers. Of the 80 primers screened, 33 did not amplify, 19 were monomorphic, and 28 gave reproducible, polymorphic DNA amplification patterns. Eleven primers were selected from the 28 for the study. The number of bands generated was primer- and genotype-dependent, and ranged from 1 to 10. No primer gave unique banding patterns for each of the 25 accessions; however, ten different combinations of 2 primer banding patterns produced unique fingerprints for each accession. A maternal half-sib (MHS) family was included among the 25 accessions to see if genetic relationships could be detected. RAPD data were used to generate simple matching coefficients, which were analyzed phenetically and by means of principal coordinate analysis (PCA). The MHS clustered together in both the phenetic and the PCA while the randomly selected accessions were scattered with no apparent pattern. The uses of RAPD analysis for Mangifera germ plasm classification and clonal identification are discussed.

Using Geographic Information Systems and Spatial Analysis Methods to Assess Household Water Access and Sanitation Coverage in the SHINE Trial.

PubMed

Ntozini, Robert; Marks, Sara J; Mangwadu, Goldberg; Mbuya, Mduduzi N N; Gerema, Grace; Mutasa, Batsirai; Julian, Timothy R; Schwab, Kellogg J; Humphrey, Jean H; Zungu, Lindiwe I

2015-12-15

Access to water and sanitation are important determinants of behavioral responses to hygiene and sanitation interventions. We estimated cluster-specific water access and sanitation coverage to inform a constrained randomization technique in the SHINE trial. Technicians and engineers inspected all public access water sources to ascertain seasonality, function, and geospatial coordinates. Households and water sources were mapped using open-source geospatial software. The distance from each household to the nearest perennial, functional, protected water source was calculated, and for each cluster, the median distance and the proportion of households within <500 m and >1500 m of such a water source. Cluster-specific sanitation coverage was ascertained using a random sample of 13 households per cluster. These parameters were included as covariates in randomization to optimize balance in water and sanitation access across treatment arms at the start of the trial. The observed high variability between clusters in both parameters suggests that constraining on these factors was needed to reduce risk of bias. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America.

Multiple-image authentication with a cascaded multilevel architecture based on amplitude field random sampling and phase information multiplexing.

PubMed

Fan, Desheng; Meng, Xiangfeng; Wang, Yurong; Yang, Xiulun; Pan, Xuemei; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

2015-04-10

A multiple-image authentication method with a cascaded multilevel architecture in the Fresnel domain is proposed, in which a synthetic encoded complex amplitude is first fabricated, and its real amplitude component is generated by iterative amplitude encoding, random sampling, and space multiplexing for the low-level certification images, while the phase component of the synthetic encoded complex amplitude is constructed by iterative phase information encoding and multiplexing for the high-level certification images. Then the synthetic encoded complex amplitude is iteratively encoded into two phase-type ciphertexts located in two different transform planes. During high-level authentication, when the two phase-type ciphertexts and the high-level decryption key are presented to the system and then the Fresnel transform is carried out, a meaningful image with good quality and a high correlation coefficient with the original certification image can be recovered in the output plane. Similar to the procedure of high-level authentication, in the case of low-level authentication with the aid of a low-level decryption key, no significant or meaningful information is retrieved, but it can result in a remarkable peak output in the nonlinear correlation coefficient of the output image and the corresponding original certification image. Therefore, the method realizes different levels of accessibility to the original certification image for different authority levels with the same cascaded multilevel architecture.

Access to and use of health services as factors associated with neonatal mortality in the North, Northeast, and Vale do Jequitinhonha regions, Brazil.

PubMed

Batista, Cristiane B; Carvalho, Márcia L de; Vasconcelos, Ana Glória G

To analyze the factors associated with neonatal mortality related to health services accessibility and use. Case-control study of live births in 2008 in small- and medium-sized municipalities in the North, Northeast, and Vale do Jequitinhonha regions, Brazil. A probabilistic sample stratified by region, population size, and information adequacy was generated for the choice of municipalities. Of these, all municipalities with 20,000 inhabitants or less were included in the study (36 municipalities), whereas the remainder were selected according to the probability method proportional to population size, totaling 20 cities with 20,001-50,000 inhabitants and 19 municipalities with 50,001-200,000 inhabitants. All deaths of live births in these cities were included. Controls were randomly sampled, considered as four times the number of cases. The sample size comprised 412 cases and 1772 controls. Hierarchical multiple logistic regression was used for data analysis. The risk factors for neonatal death were socioeconomic class D and E (OR=1.28), history of child death (OR=1.74), high-risk pregnancy (OR=4.03), peregrination in antepartum (OR=1.46), lack of prenatal care (OR=2.81), absence of professional for the monitoring of labor (OR=3.34), excessive time waiting for delivery (OR=1.97), borderline preterm birth (OR=4.09) and malformation (OR=13.66). These results suggest multiple causes of neonatal mortality, as well as the need to improve access to good quality maternal-child health care services in the assessed places of study. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Online CBT life skills programme for low mood and anxiety: study protocol for a pilot randomized controlled trial.

PubMed

Williams, Christopher; McClay, Carrie-Anne; Martinez, Rebeca; Morrison, Jill; Haig, Caroline; Jones, Ray; Farrand, Paul

2016-04-27

Low mood is a common mental health problem with significant health consequences. Studies have shown that cognitive behavioural therapy (CBT) is an effective treatment for low mood and anxiety when delivered one-to-one by an expert practitioner. However, access to this talking therapy is often limited and waiting lists can be long, although a range of low-intensity interventions that can increase access to services are available. These include guided self-help materials delivered via books, classes and online packages. This project aims to pilot a randomized controlled trial of an online CBT-based life skills course with community-based individuals experiencing low mood and anxiety. Individuals with elevated symptoms of depression will be recruited directly from the community via online and newspaper advertisements. Participants will be remotely randomized to receive either immediate access or delayed access to the Living Life to the Full guided online CBT-based life skills package, with telephone or email support provided whilst they use the online intervention. The primary end point will be at 3 months post-randomization, at which point the delayed-access group will be offered the intervention. Levels of depression, anxiety, social functioning and satisfaction will be assessed. This pilot study will test the trial design, and ability to recruit and deliver the intervention. Drop-out rates will be assessed and the completion and acceptability of the package will be investigated. The study will also inform a sample size power calculation for a subsequent substantive randomized controlled trial. ISRCTN ISRCTN12890709.

Topology-selective jamming of fully-connected, code-division random-access networks

NASA Technical Reports Server (NTRS)

Polydoros, Andreas; Cheng, Unjeng

1990-01-01

The purpose is to introduce certain models of topology selective stochastic jamming and examine its impact on a class of fully-connected, spread-spectrum, slotted ALOHA-type random access networks. The theory covers dedicated as well as half-duplex units. The dominant role of the spatial duty factor is established, and connections with the dual concept of time selective jamming are discussed. The optimal choices of coding rate and link access parameters (from the users' side) and the jamming spatial fraction are numerically established for DS and FH spreading.

The Use of a Computer-Controlled Random Access Slide Projector for Rapid Information Display.

ERIC Educational Resources Information Center

Muller, Mark T.

A 35mm random access slide projector operated in conjunction with a computer terminal was adapted to meet the need for a more rapid and complex graphic display mechanism than is currently available with teletypewriter terminals. The model projector can be operated manually to provide for a maintenance checkout of the electromechanical system.…

76 FR 45295 - In the Matter of Certain Static Random Access Memories and Products Containing Same; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-28

... supplementing the amended complaint was filed on June 28, 2011. A second amended complaint was filed on July 13... of certain static random access memories and products containing same by reason of infringement of... 13 of the `937 patent, and whether an industry in the United States exists as required by subsection...

Opportunistic Access in Frequency Hopping Cognitive Radio Networks

DTIC Science & Technology

2014-03-27

thresholding MA multiple access MFSK M-ary frequency shift keying MIMO multiple-input/multiple-output OFDM orthogonal frequency-division multiplexing x...adaptive BER performance as a function of ISR with orthogonal frequency-division multiplexing ( OFDM ) interference present. . . . . . . . . . 41 4.15 Non...adaptive BER performance as a function of EB/N0 with OFDM interfer- ence present

Assessment of wadeable stream resources in the driftless area ecoregion in Western Wisconsin using a probabilistic sampling design.

PubMed

Miller, Michael A; Colby, Alison C C; Kanehl, Paul D; Blocksom, Karen

2009-03-01

The Wisconsin Department of Natural Resources (WDNR), with support from the U.S. EPA, conducted an assessment of wadeable streams in the Driftless Area ecoregion in western Wisconsin using a probabilistic sampling design. This ecoregion encompasses 20% of Wisconsin's land area and contains 8,800 miles of perennial streams. Randomly-selected stream sites (n = 60) equally distributed among stream orders 1-4 were sampled. Watershed land use, riparian and in-stream habitat, water chemistry, macroinvertebrate, and fish assemblage data were collected at each true random site and an associated "modified-random" site on each stream that was accessed via a road crossing nearest to the true random site. Targeted least-disturbed reference sites (n = 22) were also sampled to develop reference conditions for various physical, chemical, and biological measures. Cumulative distribution function plots of various measures collected at the true random sites evaluated with reference condition thresholds, indicate that high proportions of the random sites (and by inference the entire Driftless Area wadeable stream population) show some level of degradation. Study results show no statistically significant differences between the true random and modified-random sample sites for any of the nine physical habitat, 11 water chemistry, seven macroinvertebrate, or eight fish metrics analyzed. In Wisconsin's Driftless Area, 79% of wadeable stream lengths were accessible via road crossings. While further evaluation of the statistical rigor of using a modified-random sampling design is warranted, sampling randomly-selected stream sites accessed via the nearest road crossing may provide a more economical way to apply probabilistic sampling in stream monitoring programs.

Spatial versus sequential correlations for random access coding

NASA Astrophysics Data System (ADS)

Tavakoli, Armin; Marques, Breno; Pawłowski, Marcin; Bourennane, Mohamed

2016-03-01

Random access codes are important for a wide range of applications in quantum information. However, their implementation with quantum theory can be made in two very different ways: (i) by distributing data with strong spatial correlations violating a Bell inequality or (ii) using quantum communication channels to create stronger-than-classical sequential correlations between state preparation and measurement outcome. Here we study this duality of the quantum realization. We present a family of Bell inequalities tailored to the task at hand and study their quantum violations. Remarkably, we show that the use of spatial and sequential quantum correlations imposes different limitations on the performance of quantum random access codes: Sequential correlations can outperform spatial correlations. We discuss the physics behind the observed discrepancy between spatial and sequential quantum correlations.

Design of pulse waveform for waveform division multiple access UWB wireless communication system.

PubMed

Yin, Zhendong; Wang, Zhirui; Liu, Xiaohui; Wu, Zhilu

2014-01-01

A new multiple access scheme, Waveform Division Multiple Access (WDMA) based on the orthogonal wavelet function, is presented. After studying the correlation properties of different categories of single wavelet functions, the one with the best correlation property will be chosen as the foundation for combined waveform. In the communication system, each user is assigned to different combined orthogonal waveform. Demonstrated by simulation, combined waveform is more suitable than single wavelet function to be a communication medium in WDMA system. Due to the excellent orthogonality, the bit error rate (BER) of multiuser with combined waveforms is so close to that of single user in a synchronous system. That is to say, the multiple access interference (MAI) is almost eliminated. Furthermore, even in an asynchronous system without multiuser detection after matched filters, the result is still pretty ideal and satisfactory by using the third combination mode that will be mentioned in the study.

Frequency comb-based multiple-access ultrastable frequency dissemination with 7 × 10(-17) instability.

PubMed

Zhang, Shuangyou; Zhao, Jianye

2015-01-01

In this letter, we demonstrate frequency-comb-based multiple-access ultrastable frequency dissemination over a 10-km single-mode fiber link. First, we synchronize optical pulse trains from an Er-fiber frequency comb to the remote site by using a simple and robust phase-conjugate stabilization method. The fractional frequency-transfer instability at the remote site is 2.6×10(-14) and 4.9×10(-17) for averaging times of 1 and 10,000 s, respectively. Then, we reproduce the harmonic of the repetition rate from the disseminated optical pulse trains at an arbitrary point along the fiber link to test comb-based multiple-access performance, and demonstrate frequency instability of 4×10(-14) and 7×10(-17) at 1 and 10,000 s averaging time, respectively. The proposed comb-based multiple-access frequency dissemination can easily achieve highly stable wideband microwave extraction along the whole link.

Converting laserdisc video to digital video: a demonstration project using brain animations.

PubMed

Jao, C S; Hier, D B; Brint, S U

1995-01-01

Interactive laserdiscs are of limited value in large group learning situations due to the expense of establishing multiple workstations. The authors implemented an alternative to laserdisc video by using indexed digital video combined with an expert system. High-quality video was captured from a laserdisc player and combined with waveform audio into an audio-video-interleave (AVI) file format in the Microsoft Video-for-Windows environment (Microsoft Corp., Seattle, WA). With the use of an expert system, a knowledge-based computer program provided random access to these indexed AVI files. The program can be played on any multimedia computer without the need for laserdiscs. This system offers a high level of interactive video without the overhead and cost of a laserdisc player.

AEROSAT Access Control Summary

DOT National Transportation Integrated Search

1976-10-01

The report consists of three basic sections. Section 2 is a discussion of the communications concepts germane to AEROSAT access control. It defines and reviews the principles of multiplexing, multiple access, demand access, and access control and rel...

Aerosat Access Control Summary

DOT National Transportation Integrated Search

1976-10-01

The report consists of three basic sections. Section 2 is a discussion of the communications concepts germane to AEROSAT access control. It defines and reviews the principles of multiplexing, multiple access, demand access, and access control and rel...

Querying and Computing with BioCyc Databases

PubMed Central

Krummenacker, Markus; Paley, Suzanne; Mueller, Lukas; Yan, Thomas; Karp, Peter D.

2006-01-01

Summary We describe multiple methods for accessing and querying the complex and integrated cellular data in the BioCyc family of databases: access through multiple file formats, access through Application Program Interfaces (APIs) for LISP, Perl and Java, and SQL access through the BioWarehouse relational database. Availability The Pathway Tools software and 20 BioCyc DBs in Tiers 1 and 2 are freely available to academic users; fees apply to some types of commercial use. For download instructions see http://BioCyc.org/download.shtml PMID:15961440

Radiation Effects of Commercial Resistive Random Access Memories

NASA Technical Reports Server (NTRS)

Chen, Dakai; LaBel, Kenneth A.; Berg, Melanie; Wilcox, Edward; Kim, Hak; Phan, Anthony; Figueiredo, Marco; Buchner, Stephen; Khachatrian, Ani; Roche, Nicolas

2014-01-01

We present results for the single-event effect response of commercial production-level resistive random access memories. We found that the resistive memory arrays are immune to heavy ion-induced upsets. However, the devices were susceptible to single-event functional interrupts, due to upsets from the control circuits. The intrinsic radiation tolerant nature of resistive memory makes the technology an attractive consideration for future space applications.

Vertical Launch System Loadout Planner

DTIC Science & Technology

2015-03-01

United States Navy USS United States’ Ship VBA Visual Basic for Applications VLP VLS Loadout Planner VLS Vertical Launch System...with 32 gigabytes of random access memory and eight processors, General Algebraic Modeling System (GAMS) CPLEX version 24 (GAMS, 2015) solves this...problem in ten minutes to an integer tolerance of 10%. The GAMS interpreter and CPLEX solver require 75 Megabytes of random access memory for this

Nonvolatile GaAs Random-Access Memory

NASA Technical Reports Server (NTRS)

Katti, Romney R.; Stadler, Henry L.; Wu, Jiin-Chuan

1994-01-01

Proposed random-access integrated-circuit electronic memory offers nonvolatile magnetic storage. Bits stored magnetically and read out with Hall-effect sensors. Advantages include short reading and writing times and high degree of immunity to both single-event upsets and permanent damage by ionizing radiation. Use of same basic material for both transistors and sensors simplifies fabrication process, with consequent benefits in increased yield and reduced cost.

10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.

Code of Federal Regulations, 2010 CFR

2010-01-01

... for one or more random tests after any applicable requirement for pre-access testing in §§ 26.65 or 26... individual for any pre-access testing that may be required under §§ 26.65 or 26.69, and thereafter, the... other entity relies on drug and alcohol tests that were conducted before the individual applied for...

10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.

Code of Federal Regulations, 2014 CFR

2014-01-01

... for one or more random tests after any applicable requirement for pre-access testing in § 26.65 or... individual for any pre-access testing that may be required under § 26.65 or § 26.69, and thereafter, the... other entity relies on drug and alcohol tests that were conducted before the individual applied for...

10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.

Code of Federal Regulations, 2012 CFR

2012-01-01

... for one or more random tests after any applicable requirement for pre-access testing in §§ 26.65 or 26... individual for any pre-access testing that may be required under §§ 26.65 or 26.69, and thereafter, the... other entity relies on drug and alcohol tests that were conducted before the individual applied for...

10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.

Code of Federal Regulations, 2013 CFR

2013-01-01

... for one or more random tests after any applicable requirement for pre-access testing in §§ 26.65 or 26... individual for any pre-access testing that may be required under §§ 26.65 or 26.69, and thereafter, the... other entity relies on drug and alcohol tests that were conducted before the individual applied for...

Post-Coma Persons with Extensive Multiple Disabilities Use Microswitch Technology to Access Selected Stimulus Events or Operate a Radio Device

ERIC Educational Resources Information Center

Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Alberti, Gloria; Oliva, Doretta; Megna, Gianfranco; Iliceto, Carla; Damiani, Sabino; Ricci, Irene; Spica, Antonella

2011-01-01

The present two studies extended research evidence on the use of microswitch technology by post-coma persons with multiple disabilities. Specifically, Study I examined whether three adults with a diagnosis of minimally conscious state and multiple disabilities could use microswitches as tools to access brief, selected stimulus events. Study II…

Self-taught axillary vein access without venography for pacemaker implantation: prospective randomized comparison with the cephalic vein access.

PubMed

Squara, Fabien; Tomi, Julien; Scarlatti, Didier; Theodore, Guillaume; Moceri, Pamela; Ferrari, Emile

2017-12-01

Axillary vein access for pacemaker implantation is uncommon in many centres because of the lack of training in this technique. We assessed whether the introduction of the axillary vein technique was safe and efficient as compared with cephalic vein access, in a centre where no operators had any previous experience in axillary vein puncture. Patients undergoing pacemaker implantation were randomized to axillary or cephalic vein access. All three operators had no experience nor training in axillary vein puncture, and self-learned the technique by reading a published review. Axillary vein puncture was fluoroscopy-guided without contrast venography. Cephalic access was performed by dissection of delto-pectoral groove. Venous access success, venous access duration (from skin incision to guidewire or lead in superior vena cava), procedure duration, X-ray exposure, and peri-procedural (1 month) complications were recorded. results We randomized 74 consecutive patients to axillary (n = 37) or cephalic vein access (n = 37). Axillary vein was successfully accessed in 30/37 (81.1%) patients vs. 28/37 (75.7%) of cephalic veins (P = 0.57). Venous access time was shorter in axillary group than in cephalic group [5.7 (4.4-8.3) vs. 12.2 (10.5-14.8) min, P < 0.001], as well as procedure duration [34.8 (30.6-38.4) vs. 42.0 (39.1-46.6) min, P = 0.043]. X-ray exposure and peri-procedural overall complications were comparable in both groups. Axillary puncture was safe and faster than cephalic access even for the five first procedures performed by each operator. Self-taught axillary vein puncture for pacemaker implantation seems immediately safe and faster than cephalic vein access, when performed by electrophysiologists trained to pacemaker implantation but not to axillary vein puncture. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For Permissions, please email: journals.permissions@oup.com.

Gambling involvement and increased risk of gambling problems.

PubMed

Phillips, James G; Ogeil, Rowan; Chow, Yang-Wai; Blaszczynski, Alex

2013-12-01

The opportunity to gamble has undergone rapid expansion with technology allowing for access to gambling products 24 h a day. This increased online availability challenges governments' abilities to restrict access to gambling. Indeed, the ready access to multiple forms of gambling may potentially contribute to impaired control over urges for problem gamblers. The present study considered whether problem gamblers manifested a tendency to engage in multiple forms of gambling and identified forms of gambling which were more strongly related to problem gambling. In reanalyses of two surveys (Sample 1, N = 464, Sample 2, N = 1141), significant relationships accounting for between 11.3 and 13.5% of the variance were found between the numbers of forms of gambling accessed and degree of problem. Participation in online poker, playing cards and sports wagering were linked to problem gambling. Access to multiple forms of gambling may pose difficulties for the tracking and control of gambling.

Quantum internet using code division multiple access

PubMed Central

Zhang, Jing; Liu, Yu-xi; Özdemir, Şahin Kaya; Wu, Re-Bing; Gao, Feifei; Wang, Xiang-Bin; Yang, Lan; Nori, Franco

2013-01-01

A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate different sender-receiver pairs. In comparison to other existing approaches, such as frequency division multiple access (FDMA), the proposed q-CDMA can greatly increase the information rates per channel used, especially for very noisy quantum channels. PMID:23860488

Design analysis tracking and data relay satellite simulation system

NASA Technical Reports Server (NTRS)

1974-01-01

The design and development of the equipment necessary to simulate the S-band multiple access link between user spacecraft, the Tracking and Data Relay Satellite, and a ground control terminal are discussed. The core of the S-band multiple access concept is the use of an Adaptive Ground Implemented Phased Array. The array contains thirty channels and provides the multiplexing and demultiplexing equipment required to demonstrate the ground implemented beam forming feature. The system provided will make it possible to demonstrate the performance of a desired user and ten interfering sources attempting to pass data through the multiple access system.

Study of Solid State Drives performance in PROOF distributed analysis system

NASA Astrophysics Data System (ADS)

Panitkin, S. Y.; Ernst, M.; Petkus, R.; Rind, O.; Wenaus, T.

2010-04-01

Solid State Drives (SSD) is a promising storage technology for High Energy Physics parallel analysis farms. Its combination of low random access time and relatively high read speed is very well suited for situations where multiple jobs concurrently access data located on the same drive. It also has lower energy consumption and higher vibration tolerance than Hard Disk Drive (HDD) which makes it an attractive choice in many applications raging from personal laptops to large analysis farms. The Parallel ROOT Facility - PROOF is a distributed analysis system which allows to exploit inherent event level parallelism of high energy physics data. PROOF is especially efficient together with distributed local storage systems like Xrootd, when data are distributed over computing nodes. In such an architecture the local disk subsystem I/O performance becomes a critical factor, especially when computing nodes use multi-core CPUs. We will discuss our experience with SSDs in PROOF environment. We will compare performance of HDD with SSD in I/O intensive analysis scenarios. In particular we will discuss PROOF system performance scaling with a number of simultaneously running analysis jobs.

A Toolbox for Ab Initio 3-D Reconstructions in Single-particle Electron Microscopy

PubMed Central

Voss, Neil R; Lyumkis, Dmitry; Cheng, Anchi; Lau, Pick-Wei; Mulder, Anke; Lander, Gabriel C; Brignole, Edward J; Fellmann, Denis; Irving, Christopher; Jacovetty, Erica L; Leung, Albert; Pulokas, James; Quispe, Joel D; Winkler, Hanspeter; Yoshioka, Craig; Carragher, Bridget; Potter, Clinton S

2010-01-01

Structure determination of a novel macromolecular complex via single-particle electron microscopy depends upon overcoming the challenge of establishing a reliable 3-D reconstruction using only 2-D images. There are a variety of strategies that deal with this issue, but not all of them are readily accessible and straightforward to use. We have developed a “toolbox” of ab initio reconstruction techniques that provide several options for calculating 3-D volumes in an easily managed and tightly controlled work-flow that adheres to standard conventions and formats. This toolbox is designed to streamline the reconstruction process by removing the necessity for bookkeeping, while facilitating transparent data transfer between different software packages. It currently includes procedures for calculating ab initio reconstructions via random or orthogonal tilt geometry, tomograms, and common lines, all of which have been tested using the 50S ribosomal subunit. Our goal is that the accessibility of multiple independent reconstruction algorithms via this toolbox will improve the ease with which models can be generated, and provide a means of evaluating the confidence and reliability of the final reconstructed map. PMID:20018246

Near-infrared reflectance spectroscopy predicts protein, starch, and seed weight in intact seeds of common bean ( Phaseolus vulgaris L.).

PubMed

Hacisalihoglu, Gokhan; Larbi, Bismark; Settles, A Mark

2010-01-27

The objective of this study was to explore the potential of near-infrared reflectance (NIR) spectroscopy to determine individual seed composition in common bean ( Phaseolus vulgaris L.). NIR spectra and analytical measurements of seed weight, protein, and starch were collected from 267 individual bean seeds representing 91 diverse genotypes. Partial least-squares (PLS) regression models were developed with 61 bean accessions randomly assigned to a calibration data set and 30 accessions assigned to an external validation set. Protein gave the most accurate PLS regression, with the external validation set having a standard error of prediction (SEP) = 1.6%. PLS regressions for seed weight and starch had sufficient accuracy for seed sorting applications, with SEP = 41.2 mg and 4.9%, respectively. Seed color had a clear effect on the NIR spectra, with black beans having a distinct spectral type. Seed coat color did not impact the accuracy of PLS predictions. This research demonstrates that NIR is a promising technique for simultaneous sorting of multiple seed traits in single bean seeds with no sample preparation.

Characteristics and service utilization of homeless veterans entering VA substance use treatment.

PubMed

Cox, Koriann B; Malte, Carol A; Saxon, Andrew J

2017-05-01

This article compares characteristics and health care utilization patterns of homeless veterans entering substance use disorder (SUD) treatment. Baseline self-report and medical record data were collected from 181 homeless veterans participating in a randomized trial of SUD/housing case management. Veterans, categorized as newly (n = 45), episodically (n = 61), or chronically homeless (n = 75), were compared on clinical characteristics and health care utilization in the year prior to baseline. Between-groups differences were seen in stimulant use, bipolar, and depressive disorders. A significant majority accessed VA emergency department services, and nearly half accessed inpatient services, with more utilization among chronically versus newly homeless. A majority in all groups attended VA primary care (73.5%) and mental health (56.9%) visits, and 26.7% newly, 32.8% episodically, and 56.0% chronically homeless veterans initiated multiple SUD treatment episodes (p = .002). A significant proportion of veterans struggling with homelessness and SUDs appear to remain unstable despite high utilization of VA acute and preventative services. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Multi-terabyte EIDE disk arrays running Linux RAID5

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanders, D.A.; Cremaldi, L.M.; Eschenburg, V.

2004-11-01

High-energy physics experiments are currently recording large amounts of data and in a few years will be recording prodigious quantities of data. New methods must be developed to handle this data and make analysis at universities possible. Grid Computing is one method; however, the data must be cached at the various Grid nodes. We examine some storage techniques that exploit recent developments in commodity hardware. Disk arrays using RAID level 5 (RAID-5) include both parity and striping. The striping improves access speed. The parity protects data in the event of a single disk failure, but not in the case ofmore » multiple disk failures. We report on tests of dual-processor Linux Software RAID-5 arrays and Hardware RAID-5 arrays using a 12-disk 3ware controller, in conjunction with 250 and 300 GB disks, for use in offline high-energy physics data analysis. The price of IDE disks is now less than $1/GB. These RAID-5 disk arrays can be scaled to sizes affordable to small institutions and used when fast random access at low cost is important.« less

A novel ternary content addressable memory design based on resistive random access memory with high intensity and low search energy

NASA Astrophysics Data System (ADS)

Han, Runze; Shen, Wensheng; Huang, Peng; Zhou, Zheng; Liu, Lifeng; Liu, Xiaoyan; Kang, Jinfeng

2018-04-01

A novel ternary content addressable memory (TCAM) design based on resistive random access memory (RRAM) is presented. Each TCAM cell consists of two parallel RRAM to both store and search for ternary data. The cell size of the proposed design is 8F2, enable a ∼60× cell area reduction compared with the conventional static random access memory (SRAM) based implementation. Simulation results also show that the search delay and energy consumption of the proposed design at the 64-bit word search are 2 ps and 0.18 fJ/bit/search respectively at 22 nm technology node, where significant improvements are achieved compared to previous works. The desired characteristics of RRAM for implementation of the high performance TCAM search chip are also discussed.

Random-access optical-resolution photoacoustic microscopy using a digital micromirror device

PubMed Central

Liang, Jinyang; Zhou, Yong; Winkler, Amy W.; Wang, Lidai; Maslov, Konstantin I.; Li, Chiye; Wang, Lihong V.

2013-01-01

We developed random-access optical-resolution photoacoustic microscopy using a digital micromirror device. This system can rapidly scan arbitrarily shaped regions of interest within a 40×40 μm2 imaging area with a lateral resolution of 3.6 μm. To identify a region of interest, a global structural image is first acquired, then the selected region is scanned. The random-access ability was demonstrated by imaging two static samples, a carbon fiber cross and a monolayer of red blood cells, with an acquisition rate up to 4 kilohertz. The system was then used to monitor blood flow in vivo in real time within user-selected capillaries in a mouse ear. By imaging only the capillary of interest, the frame rate was increased by up to 9.2 times. PMID:23903111

Random-access optical-resolution photoacoustic microscopy using a digital micromirror device.

PubMed

Liang, Jinyang; Zhou, Yong; Winkler, Amy W; Wang, Lidai; Maslov, Konstantin I; Li, Chiye; Wang, Lihong V

2013-08-01

We developed random-access optical-resolution photoacoustic microscopy using a digital micromirror device. This system can rapidly scan arbitrarily shaped regions of interest within a 40 μm×40 μm imaging area with a lateral resolution of 3.6 μm. To identify a region of interest, a global structural image is first acquired, then the selected region is scanned. The random-access ability was demonstrated by imaging two static samples, a carbon fiber cross and a monolayer of red blood cells, with an acquisition rate up to 4 kHz. The system was then used to monitor blood flow in vivo in real time within user-selected capillaries in a mouse ear. By imaging only the capillary of interest, the frame rate was increased by up to 9.2 times.

Is random access memory random?

NASA Technical Reports Server (NTRS)

Denning, P. J.

1986-01-01

Most software is contructed on the assumption that the programs and data are stored in random access memory (RAM). Physical limitations on the relative speeds of processor and memory elements lead to a variety of memory organizations that match processor addressing rate with memory service rate. These include interleaved and cached memory. A very high fraction of a processor's address requests can be satified from the cache without reference to the main memory. The cache requests information from main memory in blocks that can be transferred at the full memory speed. Programmers who organize algorithms for locality can realize the highest performance from these computers.

Frequency Hopping, Multiple Frequency-Shift Keying, Coding, and Optimal Partial-Band Jamming.

DTIC Science & Technology

1982-08-01

receivers appropriate for these two strategies. Each receiver is noncoherent (a coherent receiver is generally impractical) and implements hard...Advances in Coding and Modulation for Noncoherent Channels Affected by Fading, Partial Band, and Multiple- . Access Interference, in A. J. Viterbi...Modulation for Noncoherent Channels Affected by Fading, Partial Band, and Multiple-Access interference, in A. J. Viterbi, ed., Advances in Coumunication

Clandestine Transmissions and Operations of Embedded Software on Cellular Mobile Devices

DTIC Science & Technology

2011-09-01

Register EMS Enhanced Message Service FDMA Frequency Division Multiple Access GMT Greenwich Mean Time GMSC Gateway Mobile Switching Center...Message Switching Center SMS-IWMSC SMS-Interworking Mobile-Service Switching Center TCH Traffic Channels TDMA Time Division Multiple Access TP...assume the user will not attempt to re-program the device. Finally, we assume that the owner and user do not have root access and cannot disable any

An Architecture for Enabling Migration of Tactical Networks to Future Flexible Ad Hoc WBWF

DTIC Science & Technology

2010-09-01

Requirements Several multiple access schemes TDMA OFDMA SC-OFDMA, FH- CDMA , DS - CDMA , hybrid access schemes, transitions between them Dynamic...parameters algorithms depend on the multiple access scheme If DS - CDMA : handling of macro-diversity (linked to cooperative routing) TDMA and/of OFDMA...Transport format Ciphering @MAC/RLC level : SCM Physical layer (PHY) : signal processing (mod, FEC, etc) CDMA : macro-diversity CDMA , OFDMA

A Pilot Randomized Controlled Trial of the ACCESS Program: A Group Intervention to Improve Social, Adaptive Functioning, Stress Coping, and Self-Determination Outcomes in Young Adults with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Oswald, Tasha M.; Winder-Patel, Breanna; Ruder, Steven; Xing, Guibo; Stahmer, Aubyn; Solomon, Marjorie

2018-01-01

The purpose of this pilot randomized controlled trial was to investigate the acceptability and efficacy of the Acquiring Career, Coping, Executive control, Social Skills (ACCESS) Program, a group intervention tailored for young adults with autism spectrum disorder (ASD) to enhance critical skills and beliefs that promote adult functioning,…

Combined Use of Bivalirudin and Radial Access in Acute Coronary Syndromes Is Not Superior to the Use of Either One Separately: Meta-Analysis of Randomized Controlled Trials.

PubMed

Mina, George S; Gobrial, George F; Modi, Kalgi; Dominic, Paari

2016-08-08

The aim of this meta-analysis was to study the relation between access site and bivalirudin use on outcomes in patients with acute coronary syndrome (ACS). Bivalirudin and radial access use are 2 strategies that are increasingly used to lower major bleeding in patients with ACS undergoing invasive approaches. The interaction between these 2 strategies and the benefit of using them in combination are unclear. This analysis included randomized controlled trials that compared bivalirudin to heparin with or without glycoprotein IIb/IIIa inhibitors in patients with ACS and reported outcomes stratified by arterial access site. Meta-analyses of outcome data were performed on the basis of access site and anticoagulation regimen. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated from event rates using random-effects models. Eight trials with a total of 27,491 patients were included. Bivalirudin reduced major bleeding risk in patients with femoral access (OR: 0.51; 95% CI: 0.46 to 0.6; p < 0.001) but not in patients with radial access (OR: 0.75; 95% CI: 0.45 to 1.26; p = 0.28). Moreover, radial access reduced major bleeding risk in patients treated with heparin (OR: 0.57; 95% CI: 0.43 to 0.77; p < 0.001) but not in patients treated with bivalirudin (OR: 0.96; 95% CI: 0.65 to 1.41; p = 0.83). There were no differences in major adverse cardiovascular events or all-cause mortality between bivalirudin and heparin, regardless of access site. Bivalirudin reduces bleeding risk only with femoral access, and radial access reduces bleeding risk only with heparin anticoagulation. Therefore, there is no additional benefit to the combined use of bivalirudin and radial access strategies in patients with ACS. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Water sanitation, access, use and self-reported diarrheal disease in rural Honduras.

PubMed

Halder, Gabriela E; Bearman, Gonzalo; Sanogo, Kakotan; Stevens, Michael P

2013-01-01

Only 79% of individuals living in rural Honduras use improved water sources. Inadequate drinking water quality is related to diarrheal illness, which in Honduras contributes to 18.6 episodes of diarrhea per child year in children under five years of age. The purpose of this study was to examine and compare access to drinking water and sanitation, as well as self-reported diarrheal disease incidence among three proximal communities in the Department of Yoro area of Honduras. An 11-item language-specific, interviewer-administered, anonymous questionnaire was administered to 263 randomly selected adults attending a June 2011 medical brigade held in the communities of Coyoles, La Hicaca, and Lomitas. Chi-square with Fisher exact tests were utilized to compare water access, sanitation, and self-reported diarrheal incidence among these communities. Coyoles and La Hicaca used private faucets as their primary water sources. Coyoles had the greatest use of bottled water. Lomitas used rivers as their primary water source, and did not use bottled water. Mostly, females were responsible for acquiring water. Usage of multiple water sanitation methods was most common in Coyoles, while no sanitation method was most common in Lomitas. In Lomitas and La Hicaca, water filters were mostly provided via donation by non-governmental organizations. Lomitas had the highest reported incidence of diarrhea among self and other household members. Critical differences in water access, sanitation, and self-reported diarrheal incidence among three geographically distinct, yet proximal, communities highlights the need for targeted interventions even in geographically proximal rural areas.

CSMA/RN: A universal protocol for gigabit networks

NASA Technical Reports Server (NTRS)

Foudriat, E. C.; Maly, Kurt J.; Overstreet, C. Michael; Khanna, S.; Paterra, Frank

1990-01-01

Networks must provide intelligent access for nodes to share the communications resources. In the range of 100 Mbps to 1 Gbps, the demand access class of protocols were studied extensively. Many use some form of slot or reservation system and many the concept of attempt and defer to determine the presence or absence of incoming information. The random access class of protocols like shared channel systems (Ethernet), also use the concept of attempt and defer in the form of carrier sensing to alleviate the damaging effects of collisions. In CSMA/CD, the sensing of interference is on a global basis. All systems discussed above have one aspect in common, they examine activity on the network either locally or globally and react in an attempt and whatever mechanism. Of the attempt + mechanisms discussed, one is obviously missing; that is attempt and truncate. Attempt and truncate was studied in a ring configuration called the Carrier Sensed Multiple Access Ring Network (CSMA/RN). The system features of CSMA/RN are described including a discussion of the node operations for inserting and removing messages and for handling integrated traffic. The performance and operational features based on analytical and simulation studies which indicate that CSMA/RN is a useful and adaptable protocol over a wide range of network conditions are discussed. Finally, the research and development activities necessary to demonstrate and realize the potential of CSMA/RN as a universal, gigabit network protocol is outlined.

Full Duplex, Spread Spectrum Radio System

NASA Technical Reports Server (NTRS)

Harvey, Bruce A.

2000-01-01

The goal of this project was to support the development of a full duplex, spread spectrum voice communications system. The assembly and testing of a prototype system consisting of a Harris PRISM spread spectrum radio, a TMS320C54x signal processing development board and a Zilog Z80180 microprocessor was underway at the start of this project. The efforts under this project were the development of multiple access schemes, analysis of full duplex voice feedback delays, and the development and analysis of forward error correction (FEC) algorithms. The multiple access analysis involved the selection between code division multiple access (CDMA), frequency division multiple access (FDMA) and time division multiple access (TDMA). Full duplex voice feedback analysis involved the analysis of packet size and delays associated with full loop voice feedback for confirmation of radio system performance. FEC analysis included studies of the performance under the expected burst error scenario with the relatively short packet lengths, and analysis of implementation in the TMS320C54x digital signal processor. When the capabilities and the limitations of the components used were considered, the multiple access scheme chosen was a combination TDMA/FDMA scheme that will provide up to eight users on each of three separate frequencies. Packets to and from each user will consist of 16 samples at a rate of 8,000 samples per second for a total of 2 ms of voice information. The resulting voice feedback delay will therefore be 4 - 6 ms. The most practical FEC algorithm for implementation was a convolutional code with a Viterbi decoder. Interleaving of the bits of each packet will be required to offset the effects of burst errors.

A multi-level intervention in subsidized housing sites to increase fruit and vegetable access and intake: Rationale, design and methods of the 'Live Well, Viva Bien' cluster randomized trial.

PubMed

Gans, Kim M; Gorham, Gemma; Risica, Patricia M; Dulin-Keita, Akilah; Dionne, Laura; Gao, Tina; Peters, Sarah; Principato, Ludovica

2016-06-28

Adequate fruit and vegetable (F&V) intake is important for disease prevention. Yet, most Americans, especially low-income and racial/ethnic minorities, do not eat adequate amounts. These disparities are partly attributable to food environments in low-income neighborhoods where residents often have limited access to affordable, healthful food and easy access to inexpensive, unhealthful foods. Increasing access to affordable healthful food in underserved neighborhoods through mobile markets is a promising, year-round strategy for improving dietary behaviors and reducing F&V intake disparities. However, to date, there have been no randomized controlled trials studying their effectiveness. The objective of the 'Live Well, Viva Bien' (LWVB) cluster randomized controlled trial is to evaluate the efficacy of a multicomponent mobile market intervention at increasing F&V intake among residents of subsidized housing complexes. One housing complex served as a pilot site for the intervention group and the remaining 14 demographically-matched sites were randomized into either the intervention or control group. The intervention group received bimonthly, discount, mobile, fresh F&V markets in conjunction with a nutrition education intervention (two F&V campaigns, newsletters, DVDs and cooking demonstrations) for 12 months. The control group received physical activity and stress reduction interventions. Outcome measures include F&V intake (measured by two validated F&V screeners at baseline, six-month and twelve-months) along with potential psychosocial mediating variables. Extensive quantitative and qualitative process evaluation was also conducted throughout the study. Modifying neighborhood food environments in ways that increase access to affordable, healthful food is a promising strategy for improving dietary behaviors among low-income, racial and ethnic minority groups at increased risk for obesity and other food-related chronic diseases. Discount, mobile F&V markets address all the major barriers to eating more F&V (high cost, poor quality, limited access and limited time to shop and cook) and provide a year-round solution to limited access to healthful food in low-income neighborhoods. LWVB is the first randomized controlled trial evaluating the effectiveness of mobile markets at increasing F&V intake. If proven efficacious at increasing F&V consumption, LWVB could be disseminated widely to neighborhoods that have low access to fresh F&V. Clinicatrials.gov registration number: NCT02669472 First Received: January 19, 2016.

Computer-assisted instruction versus traditional lecture for medical student teaching of dermatology morphology: a randomized control trial.

PubMed

Jenkins, Sasha; Goel, Ruchika; Morrell, Dean S

2008-08-01

The effectiveness of computer-assisted instruction is unproven. To evaluate the effectiveness of an online computerized dermatology module compared to traditional lecture-based teaching to medical students. Medical students were randomized to two groups. Group 1 of 37 students had access to a computer-based dermatology tutorial. Group 2 of 36 students attended a lecture on skin morphology, identical to the tutorial, given by a dermatology faculty member. The main outcome was the total number of correct answers on a multiple-choice morphologic terminology final examination. The mean number of questions answered correctly was 16.14 and 14.89 for group 1 and group 2, respectively. Unpaired statistical t tests showed the difference in mean scores between the two groups to be 1.25 (95% confidence interval: -0.70 to 3.20, p value = .20). The study was small, with a small amount of material, and was brief in duration. Within the limits of our study, computer-assisted instruction is at least as effective as traditional lecture teaching of dermatology morphology to medical students.

A randomized study of internet parent training accessed from community technology centers.

PubMed

Irvine, A Blair; Gelatt, Vicky A; Hammond, Michael; Seeley, John R

2015-05-01

Behavioral parent training (BPT) has been shown to be efficacious to improve parenting skills for problematic interactions with adolescents displaying oppositional and antisocial behaviors. Some research suggests that support group curricula might be transferred to the Internet, and some studies suggest that other curriculum designs might also be effective. In this research, a BPT program for parents of at-risk adolescents was tested on the Internet in a randomized trial (N = 307) from computer labs at six community technology centers in or near large metropolitan areas. The instructional design was based on asynchronous scenario-based e-learning, rather than a traditional parent training model where presentation of course material builds content sequentially over multiple class sessions. Pretest to 30-day follow-up analyses indicated significant treatment effects on parent-reported discipline style (Parenting Scale, Adolescent version), child behavior (Eyberg Child Behavior Inventory), and on social cognitive theory constructs of intentions and self-efficacy. The effect sizes were small to medium. These findings suggest the potential to provide effective parent training programs on the Internet.

Understanding the patient perspective on research access to national health records databases for conduct of randomized registry trials.

PubMed

Avram, Robert; Marquis-Gravel, Guillaume; Simard, François; Pacheco, Christine; Couture, Étienne; Tremblay-Gravel, Maxime; Desplantie, Olivier; Malhamé, Isabelle; Bibas, Lior; Mansour, Samer; Parent, Marie-Claude; Farand, Paul; Harvey, Luc; Lessard, Marie-Gabrielle; Ly, Hung; Liu, Geoffrey; Hay, Annette E; Marc Jolicoeur, E

2018-07-01

Use of health administrative databases is proposed for screening and monitoring of participants in randomized registry trials. However, access to these databases raises privacy concerns. We assessed patient's preferences regarding use of personal information to link their research records with national health databases, as part of a hypothetical randomized registry trial. Cardiology patients were invited to complete an anonymous self-reported survey that ascertained preferences related to the concept of accessing government health databases for research, the type of personal identifiers to be shared and the type of follow-up preferred as participants in a hypothetical trial. A total of 590 responders completed the survey (90% response rate), the majority of which were Caucasians (90.4%), male (70.0%) with a median age of 65years (interquartile range, 8). The majority responders (80.3%) would grant researchers access to health administrative databases for screening and follow-up. To this end, responders endorsed the recording of their personal identifiers by researchers for future record linkage, including their name (90%), and health insurance number (83.9%), but fewer responders agreed with the recording of their social security number (61.4%, p<0.05 with date of birth as reference). Prior participation in a trial predicted agreement for granting researchers access to the administrative databases (OR: 1.69, 95% confidence interval: 1.03-2.90; p=0.04). The majority of Cardiology patients surveyed were supportive of use of their personal identifiers to access administrative health databases and conduct long-term monitoring in the context of a randomized registry trial. Copyright © 2018 Elsevier Ireland Ltd. All rights reserved.

An exploratory study of Taiwanese consumers' experiences of using health-related websites.

PubMed

Hsu, Li-Ling

2005-06-01

It is manifest that the rapid growth of Internet use and improvement of information technology have changed our lifestyles. In recent years, Internet use in Taiwan has increased dramatically, from 3 million users in 1998 to approximately 8.6 million by the end of 2002. The statistics imply that not only health care professionals but also laypersons rely on the Internet for health information. The purpose of this study was to explore Taiwan consumers' preferences and information needs, and the problems they encountered when getting information from medical websites. Using simple random sampling and systematic random sampling, a survey was conducted in Taipei from August 26, 2002 to October 30, 2002. Using simple random sampling and systematic random sampling, 28 boroughs (Li) were selected; the total sample number was 1043. Over one-quarter (26.8 %) of the respondents reported having never accessed the Internet, while 763 (73.2%) reported having accessed the Internet. Of the Internet users, only 396 (51.9%) had accessed health-related websites, and 367 (48.1%) reported having never accessed health-related websites. The most popular topics were disease information (46.5%), followed by diet consultation (34.8%), medical news (28.5%), and cosmetology (28.5%). The results of the survey show that a large percentage of people in Taiwan have never made good use of health information available on the websites. The reasons for not using the websites included a lack of time or Internet access skills, no motivation, dissatisfaction with the information, unreliable information be provided, and inability to locate the information needed. The author recommends to enhance health information access skills, understand the needs and preferences of consumers, promote the quality of medical websites, and improve the functions of medical websites.

Adaptive receiver structures for asynchronous CDMA systems

NASA Astrophysics Data System (ADS)

Rapajic, Predrag B.; Vucetic, Branka S.

1994-05-01

Adaptive linear and decision feedback receiver structures for coherent demodulation in asynchronous code division multiple access (CDMA) systems are considered. It is assumed that the adaptive receiver has no knowledge of the signature waveforms and timing of other users. The receiver is trained by a known training sequence prior to data transmission and continuously adjusted by an adaptive algorithm during data transmission. The proposed linear receiver is as simple as a standard single-user detector receiver consisting of a matched filter with constant coefficients, but achieves essential advantages with respect to timing recovery, multiple access interference elimination, near/far effect, narrowband and frequency-selective fading interference suppression, and user privacy. An adaptive centralized decision feedback receiver has the same advantages of the linear receiver but, in addition, achieves a further improvement in multiple access interference cancellation at the expense of higher complexity. The proposed receiver structures are tested by simulation over a channel with multipath propagation, multiple access interference, narrowband interference, and additive white Gaussian noise.

A comparison of Frequency Domain Multiple Access (FDMA) and Time Domain Multiple Access (TDMA) approaches to satellite service for low data rate Earth stations

NASA Technical Reports Server (NTRS)

Stevens, G.

1983-01-01

A technological and economic assessment is made of providing low data rate service to small earth stations by satellite at Ka-band. Various Frequency Domain Multiple Access (FDMA) and Time Domain Multiple Access (TDMA) scenarios are examined and compared on the basis of cost to the end user. Very small stations (1 to 2 meters in diameter) are found not to be viable alternatives to available terrestrial services. However, medium size (3 to 5 meters) earth stations appear to be very competitive if a minimum throughput of about 1.5 Mbs is maintained. This constrains the use of such terminals to large users and shared use by smaller users. No advantage was found to the use of FDMA. TDMA had a slight advantage from a total system viewpoint and a very significant advantage in the space segment (about 1/3 the required payload weight for an equivalent capacity).

Trial of Minocycline in a Clinically Isolated Syndrome of Multiple Sclerosis.

PubMed

Metz, Luanne M; Li, David K B; Traboulsee, Anthony L; Duquette, Pierre; Eliasziw, Misha; Cerchiaro, Graziela; Greenfield, Jamie; Riddehough, Andrew; Yeung, Michael; Kremenchutzky, Marcelo; Vorobeychik, Galina; Freedman, Mark S; Bhan, Virender; Blevins, Gregg; Marriott, James J; Grand'Maison, Francois; Lee, Liesly; Thibault, Manon; Hill, Michael D; Yong, V Wee

2017-06-01

On the basis of encouraging preliminary results, we conducted a randomized, controlled trial to determine whether minocycline reduces the risk of conversion from a first demyelinating event (also known as a clinically isolated syndrome) to multiple sclerosis. During the period from January 2009 through July 2013, we randomly assigned participants who had had their first demyelinating symptoms within the previous 180 days to receive either 100 mg of minocycline, administered orally twice daily, or placebo. Administration of minocycline or placebo was continued until a diagnosis of multiple sclerosis was established or until 24 months after randomization, whichever came first. The primary outcome was conversion to multiple sclerosis (diagnosed on the basis of the 2005 McDonald criteria) within 6 months after randomization. Secondary outcomes included conversion to multiple sclerosis within 24 months after randomization and changes on magnetic resonance imaging (MRI) at 6 months and 24 months (change in lesion volume on T 2 -weighted MRI, cumulative number of new lesions enhanced on T 1 -weighted MRI ["enhancing lesions"], and cumulative combined number of unique lesions [new enhancing lesions on T 1 -weighted MRI plus new and newly enlarged lesions on T 2 -weighted MRI]). A total of 142 eligible participants underwent randomization at 12 Canadian multiple sclerosis clinics; 72 participants were assigned to the minocycline group and 70 to the placebo group. The mean age of the participants was 35.8 years, and 68.3% were women. The unadjusted risk of conversion to multiple sclerosis within 6 months after randomization was 61.0% in the placebo group and 33.4% in the minocycline group, a difference of 27.6 percentage points (95% confidence interval [CI], 11.4 to 43.9; P=0.001). After adjustment for the number of enhancing lesions at baseline, the difference in the risk of conversion to multiple sclerosis within 6 months after randomization was 18.5 percentage points (95% CI, 3.7 to 33.3; P=0.01); the unadjusted risk difference was not significant at the 24-month secondary outcome time point (P=0.06). All secondary MRI outcomes favored minocycline over placebo at 6 months but not at 24 months. Trial withdrawals and adverse events of rash, dizziness, and dental discoloration were more frequent among participants who received minocycline than among those who received placebo. The risk of conversion from a clinically isolated syndrome to multiple sclerosis was significantly lower with minocycline than with placebo over 6 months but not over 24 months. (Funded by the Multiple Sclerosis Society of Canada; ClinicalTrials.gov number, NCT00666887 .).

Free choice access to multipoint wellness education and related services positively impacts employee wellness: a randomized and controlled trial.

PubMed

Sforzo, Gary A; Kaye, Miranda P; Calleri, David; Ngai, Nancy

2012-04-01

Examine effects of voluntary participation in employer-sponsored, multipoint wellness education programming on employee wellness. A randomized and controlled design was used to organize 96 participants into an education + access group; an access-only group, and control group. Outcome measures were made at start and end of a 12-week intervention period. Education + access improved wellness knowledge, which, in turn, enhanced life satisfaction, employee morale, and energy, and nearly improved stress level. Those who received facility access without educational programming did not reap health benefits. Employees voluntarily used the fitness facility and healthy meal cards only 1.3 and 1.5 times per week, respectively. Participants made limited and likely inadequate use of wellness opportunities. As a result, physical health benefits (eg, blood pressure, fitness parameters) were not seen in the present study. However, multipoint wellness education resulted in psychosocial health benefits in 12 weeks.

Discussing Firearm Ownership and Access as Part of Suicide Risk Assessment and Prevention: "Means Safety" versus "Means Restriction".

PubMed

Stanley, Ian H; Hom, Melanie A; Rogers, Megan L; Anestis, Michael D; Joiner, Thomas E

2017-01-01

The goal of this study was to describe the relative utility of the terms "means safety" versus "means restriction" in counseling individuals to limit their access to firearms in the context of a mock suicide risk assessment. Overall, 370 participants were randomized to read a vignette depicting a clinical scenario in which managing firearm ownership and access was discussed either using the term "means safety" or "means restriction." Participants rated the term "means safety" as significantly more acceptable and preferable than "means restriction." Participants randomized to the "means safety" condition reported greater intentions to adhere to clinicians' recommendations to limit access to a firearm for safety purposes (F[1,367] = 7.393, p = .007, [Formula: see text]). The term "means safety" may be more advantageous than "means restriction" when discussing firearm ownership and access in clinical settings and public health-oriented suicide prevention efforts.

Real-Time Data Filtering and Compression in Wide Area Simulation Networks

DTIC Science & Technology

1992-10-02

Area Simulation Networks Achieving the real-time linkage among multiple , geographically-distant, local area networks that support distributed...November 1989, pp. 52-61. [IEEE85] IEEE/ANSI Standard 8802/3 "Carrier sense multiple access with collision detection (CSMA/CD) access method and...decoding/encoding of multiple bits. The hardware is programmable, easily adaptable and yields a high compression rate. A prototype 2-micron VLSI chip

Evaluation of CDMA system capacity for mobile satellite system applications

NASA Technical Reports Server (NTRS)

Smith, Partrick O.; Geraniotis, Evaggelos A.

1988-01-01

A specific Direct-Sequence/Pseudo-Noise (DS/PN) Code-Division Multiple-Access (CDMA) mobile satellite system (MSAT) architecture is discussed. The performance of this system is evaluated in terms of the maximum number of active MSAT subscribers that can be supported at a given uncoded bit-error probability. The evaluation decouples the analysis of the multiple-access capability (i.e., the number of instantaneous user signals) from the analysis of the multiple-access mutliplier effect allowed by the use of CDMA with burst-modem operation. We combine the results of these two analyses and present numerical results for scenarios of interest to the mobile satellite system community.

Asynchronous, Decentralized DS-CDMA Using Feedback-Controlled Spreading Sequences for Time-Dispersive Channels

NASA Astrophysics Data System (ADS)

Miyatake, Teruhiko; Chiba, Kazuki; Hamamura, Masanori; Tachikawa, Shin'ichi

We propose a novel asynchronous direct-sequence codedivision multiple access (DS-CDMA) using feedback-controlled spreading sequences (FCSSs) (FCSS/DS-CDMA). At the receiver of FCSS/DS-CDMA, the code-orthogonalizing filter (COF) produces a spreading sequence, and the receiver returns the spreading sequence to the transmitter. Then the transmitter uses the spreading sequence as its updated version. The performance of FCSS/DS-CDMA is evaluated over time-dispersive channels. The results indicate that FCSS/DS-CDMA greatly suppresses both the intersymbol interference (ISI) and multiple access interference (MAI) over time-invariant channels. FCSS/DS-CDMA is applicable to the decentralized multiple access.

Critical side channel effects in random bit generation with multiple semiconductor lasers in a polarization-based quantum key distribution system.

PubMed

Ko, Heasin; Choi, Byung-Seok; Choe, Joong-Seon; Kim, Kap-Joong; Kim, Jong-Hoi; Youn, Chun Ju

2017-08-21

Most polarization-based BB84 quantum key distribution (QKD) systems utilize multiple lasers to generate one of four polarization quantum states randomly. However, random bit generation with multiple lasers can potentially open critical side channels that significantly endangers the security of QKD systems. In this paper, we show unnoticed side channels of temporal disparity and intensity fluctuation, which possibly exist in the operation of multiple semiconductor laser diodes. Experimental results show that the side channels can enormously degrade security performance of QKD systems. An important system issue for the improvement of quantum bit error rate (QBER) related with laser driving condition is further addressed with experimental results.

Non-volatile magnetic random access memory

NASA Technical Reports Server (NTRS)

Katti, Romney R. (Inventor); Stadler, Henry L. (Inventor); Wu, Jiin-Chuan (Inventor)

1994-01-01

Improvements are made in a non-volatile magnetic random access memory. Such a memory is comprised of an array of unit cells, each having a Hall-effect sensor and a thin-film magnetic element made of material having an in-plane, uniaxial anisotropy and in-plane, bipolar remanent magnetization states. The Hall-effect sensor is made more sensitive by using a 1 m thick molecular beam epitaxy grown InAs layer on a silicon substrate by employing a GaAs/AlGaAs/InAlAs superlattice buffering layer. One improvement avoids current shunting problems of matrix architecture. Another improvement reduces the required magnetizing current for the micromagnets. Another improvement relates to the use of GaAs technology wherein high electron-mobility GaAs MESFETs provide faster switching times. Still another improvement relates to a method for configuring the invention as a three-dimensional random access memory.

Carbon nanomaterials for non-volatile memories

NASA Astrophysics Data System (ADS)

Ahn, Ethan C.; Wong, H.-S. Philip; Pop, Eric

2018-03-01

Carbon can create various low-dimensional nanostructures with remarkable electronic, optical, mechanical and thermal properties. These features make carbon nanomaterials especially interesting for next-generation memory and storage devices, such as resistive random access memory, phase-change memory, spin-transfer-torque magnetic random access memory and ferroelectric random access memory. Non-volatile memories greatly benefit from the use of carbon nanomaterials in terms of bit density and energy efficiency. In this Review, we discuss sp2-hybridized carbon-based low-dimensional nanostructures, such as fullerene, carbon nanotubes and graphene, in the context of non-volatile memory devices and architectures. Applications of carbon nanomaterials as memory electrodes, interfacial engineering layers, resistive-switching media, and scalable, high-performance memory selectors are investigated. Finally, we compare the different memory technologies in terms of writing energy and time, and highlight major challenges in the manufacturing, integration and understanding of the physical mechanisms and material properties.

A Brief Survey of Media Access Control, Data Link Layer, and Protocol Technologies for Lunar Surface Communications

NASA Technical Reports Server (NTRS)

Wallett, Thomas M.

2009-01-01

This paper surveys and describes some of the existing media access control and data link layer technologies for possible application in lunar surface communications and the advanced wideband Direct Sequence Code Division Multiple Access (DSCDMA) conceptual systems utilizing phased-array technology that will evolve in the next decade. Time Domain Multiple Access (TDMA) and Code Division Multiple Access (CDMA) are standard Media Access Control (MAC) techniques that can be incorporated into lunar surface communications architectures. Another novel hybrid technique that is recently being developed for use with smart antenna technology combines the advantages of CDMA with those of TDMA. The relatively new and sundry wireless LAN data link layer protocols that are continually under development offer distinct advantages for lunar surface applications over the legacy protocols which are not wireless. Also several communication transport and routing protocols can be chosen with characteristics commensurate with smart antenna systems to provide spacecraft communications for links exhibiting high capacity on the surface of the Moon. The proper choices depend on the specific communication requirements.

Implementation of nitrogen-doped titanium-tungsten tunable heater in phase change random access memory and its effects on device performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, Chun Chia; Zhao, Rong, E-mail: zhao-rong@sutd.edu.sg; Chong, Tow Chong

2014-10-13

Nitrogen-doped titanium-tungsten (N-TiW) was proposed as a tunable heater in Phase Change Random Access Memory (PCRAM). By tuning N-TiW's material properties through doping, the heater can be tailored to optimize the access speed and programming current of PCRAM. Experiments reveal that N-TiW's resistivity increases and thermal conductivity decreases with increasing nitrogen-doping ratio, and N-TiW devices displayed (∼33% to ∼55%) reduced programming currents. However, there is a tradeoff between the current and speed for heater-based PCRAM. Analysis of devices with different N-TiW heaters shows that N-TiW doping levels could be optimized to enable low RESET currents and fast access speeds.

Two way time transfer results at NRL and USNO

NASA Technical Reports Server (NTRS)

Galysh, Ivan J.; Landis, G. Paul

1993-01-01

The Naval Research Laboratory (NRL) has developed a two way time transfer modem system for the United States Naval Observatory (USNO). Two modems in conjunction with a pair of Very Small Aperture Terminal (VSAT) and a communication satellite can achieve sub nanosecond time transfer. This performance is demonstrated by the results of testing at and between NRL and USNO. The modems use Code Division Multiple Access (CDMA) methods to separate their signals through a single path in the satellite. Each modem transmitted a different Pseudo Random Noise (PRN) code and received the others PRN code. High precision time transfer is possible with two way methods because of reciprocity of many of the terms of the path and hardware delay between the two modems. The hardware description was given in a previous paper.

Electrically-controlled nonlinear switching and multi-level storage characteristics in WOx film-based memory cells

NASA Astrophysics Data System (ADS)

Duan, W. J.; Wang, J. B.; Zhong, X. L.

2018-05-01

Resistive switching random access memory (RRAM) is considered as a promising candidate for the next generation memory due to its scalability, high integration density and non-volatile storage characteristics. Here, the multiple electrical characteristics in Pt/WOx/Pt cells are investigated. Both of the nonlinear switching and multi-level storage can be achieved by setting different compliance current in the same cell. The correlations among the current, time and temperature are analyzed by using contours and 3D surfaces. The switching mechanism is explained in terms of the formation and rupture of conductive filament which is related to oxygen vacancies. The experimental results show that the non-stoichiometric WOx film-based device offers a feasible way for the applications of oxide-based RRAMs.

Incredible Years parenting interventions: current effectiveness research and future directions.

PubMed

Gardner, Frances; Leijten, Patty

2017-06-01

The Incredible Years parenting intervention is a social learning theory-based programme for reducing children's conduct problems. Dozens of randomized trials, many by independent investigators, find consistent effects of Incredible Years on children's conduct problems across multiple countries and settings. However, in common with other interventions, these average effects hide much variability in the responses of individual children and families. Innovative moderator research is needed to enhance scientific understanding of why individual children and parents respond differently to intervention. Additionally, research is needed to test whether there are ways to make Incredible Years more effective and accessible for families and service providers, especially in low resource settings, by developing innovative delivery systems using new media, and by systematically testing for essential components of parenting interventions. Copyright © 2017. Published by Elsevier Ltd.

Binary Sequences for Spread-Spectrum Multiple-Access Communication

DTIC Science & Technology

1977-08-01

Massey, J. L., and Uhran, J. J., Jr., "Sub-baud coding," Proceedings of the Thirteenth Annual Allerton Conference on Circuit and System Theory, pp. 539...sequences in a multipl.e access environment," Proceedings of the Thirteenth Annual AIlerton Conference on Circuit and System Theory, pp. 21-27, October...34 Proceedings of the Thirteenth Annual Allertcn Conference on Circuit and System Theory, pp. 548-559, October 1975. Yao, K., *Performance bounds on

A Systematic Analysis of Factors Localized to Damaged Chromatin Reveals PARP-Dependent Recruitment of Transcription Factors.

PubMed

Izhar, Lior; Adamson, Britt; Ciccia, Alberto; Lewis, Jedd; Pontano-Vaites, Laura; Leng, Yumei; Liang, Anthony C; Westbrook, Thomas F; Harper, J Wade; Elledge, Stephen J

2015-06-09

Localization to sites of DNA damage is a hallmark of DNA damage response (DDR) proteins. To identify DDR factors, we screened epitope-tagged proteins for localization to sites of chromatin damaged by UV laser microirradiation and found >120 proteins that localize to damaged chromatin. These include the BAF tumor suppressor complex and the amyotrophic lateral sclerosis (ALS) candidate protein TAF15. TAF15 contains multiple domains that bind damaged chromatin in a poly-(ADP-ribose) polymerase (PARP)-dependent manner, suggesting a possible role as glue that tethers multiple PAR chains together. Many positives were transcription factors; > 70% of randomly tested transcription factors localized to sites of DNA damage, and of these, ∼90% were PARP dependent for localization. Mutational analyses showed that localization to damaged chromatin is DNA-binding-domain dependent. By examining Hoechst staining patterns at damage sites, we see evidence of chromatin decompaction that is PARP dependent. We propose that PARP-regulated chromatin remodeling at sites of damage allows transient accessibility of DNA-binding proteins. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Collaborative Indoor Access Point Localization Using Autonomous Mobile Robot Swarm.

PubMed

Awad, Fahed; Naserllah, Muhammad; Omar, Ammar; Abu-Hantash, Alaa; Al-Taj, Abrar

2018-01-31

Localization of access points has become an important research problem due to the wide range of applications it addresses such as dismantling critical security threats caused by rogue access points or optimizing wireless coverage of access points within a service area. Existing proposed solutions have mostly relied on theoretical hypotheses or computer simulation to demonstrate the efficiency of their methods. The techniques that rely on estimating the distance using samples of the received signal strength usually assume prior knowledge of the signal propagation characteristics of the indoor environment in hand and tend to take a relatively large number of uniformly distributed random samples. This paper presents an efficient and practical collaborative approach to detect the location of an access point in an indoor environment without any prior knowledge of the environment. The proposed approach comprises a swarm of wirelessly connected mobile robots that collaboratively and autonomously collect a relatively small number of non-uniformly distributed random samples of the access point's received signal strength. These samples are used to efficiently and accurately estimate the location of the access point. The experimental testing verified that the proposed approach can identify the location of the access point in an accurate and efficient manner.

Collaborative Indoor Access Point Localization Using Autonomous Mobile Robot Swarm

PubMed Central

Awad, Fahed; Naserllah, Muhammad; Omar, Ammar; Abu-Hantash, Alaa; Al-Taj, Abrar

2018-01-01

Localization of access points has become an important research problem due to the wide range of applications it addresses such as dismantling critical security threats caused by rogue access points or optimizing wireless coverage of access points within a service area. Existing proposed solutions have mostly relied on theoretical hypotheses or computer simulation to demonstrate the efficiency of their methods. The techniques that rely on estimating the distance using samples of the received signal strength usually assume prior knowledge of the signal propagation characteristics of the indoor environment in hand and tend to take a relatively large number of uniformly distributed random samples. This paper presents an efficient and practical collaborative approach to detect the location of an access point in an indoor environment without any prior knowledge of the environment. The proposed approach comprises a swarm of wirelessly connected mobile robots that collaboratively and autonomously collect a relatively small number of non-uniformly distributed random samples of the access point’s received signal strength. These samples are used to efficiently and accurately estimate the location of the access point. The experimental testing verified that the proposed approach can identify the location of the access point in an accurate and efficient manner. PMID:29385042

Math and science technology access and use in South Dakota public schools grades three through five

NASA Astrophysics Data System (ADS)

Schwietert, Debra L.

The development of K-12 technology standards, soon to be added to state testing of technology proficiency, and the increasing presence of computers in homes and classrooms reflects the growing importance of technology in current society. This study examined math and science teachers' responses on a survey of technology use in grades three through five in South Dakota. A researcher-developed survey instrument was used to collect data from a random sample of 100 public schools throughout the South Dakota. Forced choice and open-ended responses were recorded. Most teachers have access to computers, but they lack resources to purchase software for their content areas, especially in science areas. Three-fourths of teachers in this study reported multiple computers in their classrooms and 67% reported access to labs in other areas of the school building. These numbers are lower than the national average of 84% of teachers with computers in their classrooms and 95% with access to computers elsewhere in the building (USDOE, 2000). Almost eight out of 10 teachers noted time as a barrier to learning more about educational software. Additional barriers included lack of school funds (38%), access to relevant training (32%), personal funds (30%), and poor quality of training (7%). Teachers most often use math and science software as supplemental, with practice tutorials cited as another common use. The most common interest for software was math for both boys and girls. The second most common choice for boys was science and for girls, language arts. Teachers reported that there was no preference for either individual or group work on computers for girls or boys. Most teachers do not systematically evaluate software for gender preferences, but review software over subjectively.

A Retrospective Look at Website Accessibility over Time

ERIC Educational Resources Information Center

Hackett, Stephanie; Parmanto, Bambang; Zeng, Xiaoming

2005-01-01

Websites were retrospectively analysed to study the effects that technological advances in web design have had on accessibility for persons with disabilities. A random sample of general websites and a convenience sample of US government websites were studied and compared for the years 1997-2002. Web accessibility barrier (WAB) and complexity…

Crowdsourcing reproducible seizure forecasting in human and canine epilepsy.

PubMed

Brinkmann, Benjamin H; Wagenaar, Joost; Abbot, Drew; Adkins, Phillip; Bosshard, Simone C; Chen, Min; Tieng, Quang M; He, Jialune; Muñoz-Almaraz, F J; Botella-Rocamora, Paloma; Pardo, Juan; Zamora-Martinez, Francisco; Hills, Michael; Wu, Wei; Korshunova, Iryna; Cukierski, Will; Vite, Charles; Patterson, Edward E; Litt, Brian; Worrell, Gregory A

2016-06-01

SEE MORMANN AND ANDRZEJAK DOI101093/BRAIN/AWW091 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE  : Accurate forecasting of epileptic seizures has the potential to transform clinical epilepsy care. However, progress toward reliable seizure forecasting has been hampered by lack of open access to long duration recordings with an adequate number of seizures for investigators to rigorously compare algorithms and results. A seizure forecasting competition was conducted on kaggle.com using open access chronic ambulatory intracranial electroencephalography from five canines with naturally occurring epilepsy and two humans undergoing prolonged wide bandwidth intracranial electroencephalographic monitoring. Data were provided to participants as 10-min interictal and preictal clips, with approximately half of the 60 GB data bundle labelled (interictal/preictal) for algorithm training and half unlabelled for evaluation. The contestants developed custom algorithms and uploaded their classifications (interictal/preictal) for the unknown testing data, and a randomly selected 40% of data segments were scored and results broadcasted on a public leader board. The contest ran from August to November 2014, and 654 participants submitted 17 856 classifications of the unlabelled test data. The top performing entry scored 0.84 area under the classification curve. Following the contest, additional held-out unlabelled data clips were provided to the top 10 participants and they submitted classifications for the new unseen data. The resulting area under the classification curves were well above chance forecasting, but did show a mean 6.54 ± 2.45% (min, max: 0.30, 20.2) decline in performance. The kaggle.com model using open access data and algorithms generated reproducible research that advanced seizure forecasting. The overall performance from multiple contestants on unseen data was better than a random predictor, and demonstrates the feasibility of seizure forecasting in canine and human epilepsy.media-1vid110.1093/brain/aww045_video_abstractaww045_video_abstract. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

Electrical Evaluation of RCA MWS5001D Random Access Memory, Volume 5, Appendix D

NASA Technical Reports Server (NTRS)

Klute, A.

1979-01-01

The electrical characterization and qualification test results are presented for the RCA MWS 5001D random access memory. The tests included functional tests, AC and DC parametric tests, AC parametric worst-case pattern selection test, determination of worst-case transition for setup and hold times, and a series of schmoo plots. Average input high current, worst case input high current, output low current, and data setup time are some of the results presented.

Electrical Evaluation of RCA MWS5001D Random Access Memory, Volume 4, Appendix C

NASA Technical Reports Server (NTRS)

Klute, A.

1979-01-01

The electrical characterization and qualification test results are presented for the RCA MWS5001D random access memory. The tests included functional tests, AC and DC parametric tests, AC parametric worst-case pattern selection test, determination of worst-case transition for setup and hold times, and a series of schmoo plots. Statistical analysis data is supplied along with write pulse width, read cycle time, write cycle time, and chip enable time data.

Evaluation of 19,460 Wheat Accessions Conserved in the Indian National Genebank to Identify New Sources of Resistance to Rust and Spot Blotch Diseases.

PubMed

Kumar, Sundeep; Archak, Sunil; Tyagi, R K; Kumar, Jagdish; Vk, Vikas; Jacob, Sherry R; Srinivasan, Kalyani; Radhamani, J; Parimalan, R; Sivaswamy, M; Tyagi, Sandhya; Yadav, Mamata; Kumari, Jyotisna; Deepali; Sharma, Sandeep; Bhagat, Indoo; Meeta, Madhu; Bains, N S; Chowdhury, A K; Saha, B C; Bhattacharya, P M; Kumari, Jyoti; Singh, M C; Gangwar, O P; Prasad, P; Bharadwaj, S C; Gogoi, Robin; Sharma, J B; Gm, Sandeep Kumar; Saharan, M S; Bag, Manas; Roy, Anirban; Prasad, T V; Sharma, R K; Dutta, M; Sharma, Indu; Bansal, K C

2016-01-01

A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat-Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011-14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu), a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab), a hotspot for stripe rust and at Cooch Behar (West Bengal), a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels.

Evaluation of 19,460 Wheat Accessions Conserved in the Indian National Genebank to Identify New Sources of Resistance to Rust and Spot Blotch Diseases

PubMed Central

Jacob, Sherry R.; Srinivasan, Kalyani; Radhamani, J.; Parimalan, R.; Sivaswamy, M.; Tyagi, Sandhya; Yadav, Mamata; Kumari, Jyotisna; Deepali; Sharma, Sandeep; Bhagat, Indoo; Meeta, Madhu; Bains, N. S.; Chowdhury, A. K.; Saha, B. C.; Bhattacharya, P. M.; Kumari, Jyoti; Singh, M. C.; Gangwar, O. P.; Prasad, P.; Bharadwaj, S. C.; Gogoi, Robin; Sharma, J. B.; GM, Sandeep Kumar; Saharan, M. S.; Bag, Manas; Roy, Anirban; Prasad, T. V.; Sharma, R. K.; Dutta, M.; Sharma, Indu; Bansal, K. C.

2016-01-01

A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat–Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011–14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu), a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab), a hotspot for stripe rust and at Cooch Behar (West Bengal), a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels. PMID:27942031

Random Access Memories: A New Paradigm for Target Detection in High Resolution Aerial Remote Sensing Images.

PubMed

Zou, Zhengxia; Shi, Zhenwei

2018-03-01

We propose a new paradigm for target detection in high resolution aerial remote sensing images under small target priors. Previous remote sensing target detection methods frame the detection as learning of detection model + inference of class-label and bounding-box coordinates. Instead, we formulate it from a Bayesian view that at inference stage, the detection model is adaptively updated to maximize its posterior that is determined by both training and observation. We call this paradigm "random access memories (RAM)." In this paradigm, "Memories" can be interpreted as any model distribution learned from training data and "random access" means accessing memories and randomly adjusting the model at detection phase to obtain better adaptivity to any unseen distribution of test data. By leveraging some latest detection techniques e.g., deep Convolutional Neural Networks and multi-scale anchors, experimental results on a public remote sensing target detection data set show our method outperforms several other state of the art methods. We also introduce a new data set "LEarning, VIsion and Remote sensing laboratory (LEVIR)", which is one order of magnitude larger than other data sets of this field. LEVIR consists of a large set of Google Earth images, with over 22 k images and 10 k independently labeled targets. RAM gives noticeable upgrade of accuracy (an mean average precision improvement of 1% ~ 4%) of our baseline detectors with acceptable computational overhead.

Heterodyne detection using spectral line pairing for spectral phase encoding optical code division multiple access and dynamic dispersion compensation.

PubMed

Yang, Yi; Foster, Mark; Khurgin, Jacob B; Cooper, A Brinton

2012-07-30

A novel coherent optical code-division multiple access (OCDMA) scheme is proposed that uses spectral line pairing to generate signals suitable for heterodyne decoding. Both signal and local reference are transmitted via a single optical fiber and a simple balanced receiver performs sourceless heterodyne detection, canceling speckle noise and multiple-access interference (MAI). To validate the idea, a 16 user fully loaded phase encoded system is simulated. Effects of fiber dispersion on system performance are studied as well. Both second and third order dispersion management is achieved by using a spectral phase encoder to adjust phase shifts of spectral components at the optical network unit (ONU).

Comparison of CDMA and FDMA for the MobileStar(sm) system

NASA Technical Reports Server (NTRS)

Jacobs, I. M.; Gilhousen, K. S.; Weaver, L. A.; Renshaw, K.; Murphy, T.

1988-01-01

Spread-spectrum code division multiple access (CDMA) and single channel per carrier frequency division multiple access (FDMA) systems are compared for spectrum efficiency. CDMA is shown to have greater maximum throughput than FDMA for the MobileStar(sm) system which uses digital voice activated carriers and directive circularly polarized satellite antennas.

Wireless Computing Architecture III

DTIC Science & Technology

2013-09-01

MIMO Multiple-Input and Multiple-Output MIMO /CON MIMO with concurrent hannel access and estimation MU- MIMO Multiuser MIMO OFDM Orthogonal...compressive sensing \\; a design for concurrent channel estimation in scalable multiuser MIMO networking; and novel networking protocols based on machine...Network, Antenna Arrays, UAV networking, Angle of Arrival, Localization MIMO , Access Point, Channel State Information, Compressive Sensing 16

Electromagnetic interference-aware transmission scheduling and power control for dynamic wireless access in hospital environments.

PubMed

Phunchongharn, Phond; Hossain, Ekram; Camorlinga, Sergio

2011-11-01

We study the multiple access problem for e-Health applications (referred to as secondary users) coexisting with medical devices (referred to as primary or protected users) in a hospital environment. In particular, we focus on transmission scheduling and power control of secondary users in multiple spatial reuse time-division multiple access (STDMA) networks. The objective is to maximize the spectrum utilization of secondary users and minimize their power consumption subject to the electromagnetic interference (EMI) constraints for active and passive medical devices and minimum throughput guarantee for secondary users. The multiple access problem is formulated as a dual objective optimization problem which is shown to be NP-complete. We propose a joint scheduling and power control algorithm based on a greedy approach to solve the problem with much lower computational complexity. To this end, an enhanced greedy algorithm is proposed to improve the performance of the greedy algorithm by finding the optimal sequence of secondary users for scheduling. Using extensive simulations, the tradeoff in performance in terms of spectrum utilization, energy consumption, and computational complexity is evaluated for both the algorithms.

Embedding a randomized clinical trial into an ongoing registry infrastructure: unique opportunities for efficiency in design of the Study of Access site For Enhancement of Percutaneous Coronary Intervention for Women (SAFE-PCI for Women).

PubMed

Hess, Connie N; Rao, Sunil V; Kong, David F; Aberle, Laura H; Anstrom, Kevin J; Gibson, C Michael; Gilchrist, Ian C; Jacobs, Alice K; Jolly, Sanjit S; Mehran, Roxana; Messenger, John C; Newby, L Kristin; Waksman, Ron; Krucoff, Mitchell W

2013-09-01

Women are at higher risk than men for bleeding and vascular complications after percutaneous coronary intervention (PCI). Compared with femoral access, radial access reduces these complications but may be more challenging in women because of higher rates of radial artery spasm, tortuosity, and occlusion as well as lower rates of procedure success. Whether the safety advantages of radial versus femoral access in women undergoing PCI are outweighed by reduced effectiveness has not been studied. The Study of Access site For Enhancement of PCI for Women is a prospective, randomized clinical trial comparing radial with femoral arterial access in women undergoing PCI. In conjunction with the US Food and Drug Administration's Critical Path Cardiac Safety Research Consortium, this study embeds the randomized clinical trial into the existing infrastructure of the National Cardiovascular Data Registry CathPCI Registry through the National Institute of Health's National Cardiovascular Research Infrastructure. The primary efficacy end point is a composite of bleeding (Bleeding Academic Research Consortium types 2, 3, or 5) or vascular complication requiring intervention occurring at 72 hours after PCI or by hospital discharge. The primary feasibility end point is procedure success. Secondary end points include procedure duration, contrast volume, radiation dose, quality of life, and a composite of 30-day death, vascular complication, or unplanned revascularization. © 2013.

Multiple Intimate Partner Violence Experiences: Knowledge, Access, Utilization and Barriers to Utilization of Resources by Women of the African Diaspora.

PubMed

Sabri, Bushra; Huerta, Julia; Alexander, Kamila A; St Vil, Noelle M; Campbell, Jacquelyn C; Callwood, Gloria B

2015-11-01

This study examined knowledge, access, utilization, and barriers to use of resources among Black women exposed to multiple types of intimate partner violence in Baltimore, Maryland and the U.S. Virgin Islands (USVI). We analyzed quantitative survey data collected by 163 women recruited from primary care, prenatal or family planning clinics in Baltimore and the USVI. In addition we analyzed qualitative data from in-depth interviews with 11 women. Quantitative data were analyzed using descriptive statistics and qualitative data were analyzed using thematic analysis. A substantial proportion of Black women with multiple types of violence experiences lacked knowledge of, did not have access to, and did not use resources. Barriers to resource use were identified at the individual, relationship, and community levels. There is need for programs to develop awareness, promote access and utilization of resources, and eliminate barriers to resource use among abused Black women.

A Randomized Cadaver Study Comparing First-Attempt Success Between Tibial and Humeral Intraosseous Insertions Using NIO Device by Paramedics: A Preliminary Investigation.

PubMed

Szarpak, Lukasz; Truszewski, Zenon; Smereka, Jacek; Krajewski, Paweł; Fudalej, Marcin; Adamczyk, Piotr; Czyzewski, Lukasz

2016-05-01

Medical personnel may encounter difficulties in obtaining intravenous (IV) access during cardiac arrest. The 2015 American Heart Association guidelines and the 2015 European Resuscitation Council guidelines for cardiopulmonary resuscitation (CPR) suggest that rescuers establish intraosseous (IO) access if an IV line is not easily obtainable.The aim of the study was to compare the success rates of the IO proximal tibia and proximal humerus head access performed by paramedics using the New Intraosseous access device (NIO; Persys Medical, Houston, TX, USA) in an adult cadaver model during simulated CPR.In an interventional, randomized, crossover, single-center cadaver study, a semi-automatic spring-load driven NIO access device was investigated. In total, 84 paramedics with less than 5-year experience in Emergency Medical Service participated in the study. The trial was performed on 42 adult cadavers. In each cadaver, 2 IO accesses to the humerus head, and 2 IO accesses to the proximal tibia were obtained.The success rate of the first IO attempt was 89.3% (75/84) for tibial access, and 73.8% (62/84) for humeral access (P = 0.017). The procedure times were significantly faster for tibial access [16.8 (interquartile range, IQR, 15.1-19.9] s] than humeral access [26.7 (IQR, 22.1-30.9) s] (P < 0.001).Tibial IO access is easier and faster to put in place than humeral IO access. Humeral IO access can be an alternative method to tibial IO access. clinicaltrials.gov Identifier: NCT02700867.

Prospective Durability Testing of a Vascular Access Phantom

DTIC Science & Technology

2010-09-01

ultrasound guidance when obtaining central venous access.19,20 The increasing use of ultrasound guidance for vascular access has created an educational...with difficult intravenous access. Ann Emerg Med. 2005;46:456-61. 7. Gallieni M, Cozzolino M. Uncomplicated central vein catheterization of high risk...al. Randomized, controlled clinical trial of point-of-care limited ultrasonography assistance of central venous cannulation: The third sonography

Multiple-choice tests stabilize access to marginal knowledge.

PubMed

Cantor, Allison D; Eslick, Andrea N; Marsh, Elizabeth J; Bjork, Robert A; Bjork, Elizabeth Ligon

2015-02-01

Marginal knowledge refers to knowledge that is stored in memory, but is not accessible at a given moment. For example, one might struggle to remember who wrote The Call of the Wild, even if that knowledge is stored in memory. Knowing how best to stabilize access to marginal knowledge is important, given that new learning often requires accessing and building on prior knowledge. While even a single opportunity to restudy marginal knowledge boosts its later accessibility (Berger, Hall, & Bahrick, 1999), in many situations explicit relearning opportunities are not available. Our question is whether multiple-choice tests (which by definition expose the learner to the correct answers) can also serve this function and, if so, how testing compares to restudying given that tests can be particularly powerful learning devices (Roediger & Karpicke, 2006). In four experiments, we found that multiple-choice testing had the power to stabilize access to marginal knowledge, and to do so for at least up to a week. Importantly, such tests did not need to be paired with feedback, although testing was no more powerful than studying. Overall, the results support the idea that one's knowledge base is unstable, with individual pieces of information coming in and out of reach. The present findings have implications for a key educational challenge: ensuring that students have continuing access to information they have learned.

Performance Analysis of a New Coded TH-CDMA Scheme in Dispersive Infrared Channel with Additive Gaussian Noise

NASA Astrophysics Data System (ADS)

Hamdi, Mazda; Kenari, Masoumeh Nasiri

2013-06-01

We consider a time-hopping based multiple access scheme introduced in [1] for communication over dispersive infrared links, and evaluate its performance for correlator and matched filter receivers. In the investigated time-hopping code division multiple access (TH-CDMA) method, the transmitter benefits a low rate convolutional encoder. In this method, the bit interval is divided into Nc chips and the output of the encoder along with a PN sequence assigned to the user determines the position of the chip in which the optical pulse is transmitted. We evaluate the multiple access performance of the system for correlation receiver considering background noise which is modeled as White Gaussian noise due to its large intensity. For the correlation receiver, the results show that for a fixed processing gain, at high transmit power, where the multiple access interference has the dominant effect, the performance improves by the coding gain. But at low transmit power, in which the increase of coding gain leads to the decrease of the chip time, and consequently, to more corruption due to the channel dispersion, there exists an optimum value for the coding gain. However, for the matched filter, the performance always improves by the coding gain. The results show that the matched filter receiver outperforms the correlation receiver in the considered cases. Our results show that, for the same bandwidth and bit rate, the proposed system excels other multiple access techniques, like conventional CDMA and time hopping scheme.

Random-access scanning microscopy for 3D imaging in awake behaving animals

PubMed Central

Nadella, K. M. Naga Srinivas; Roš, Hana; Baragli, Chiara; Griffiths, Victoria A.; Konstantinou, George; Koimtzis, Theo; Evans, Geoffrey J.; Kirkby, Paul A.; Silver, R. Angus

2018-01-01

Understanding how neural circuits process information requires rapid measurements from identified neurons distributed in 3D space. Here we describe an acousto-optic lens two-photon microscope that performs high-speed focussing and line-scanning within a volume spanning hundreds of micrometres. We demonstrate its random access functionality by selectively imaging cerebellar interneurons sparsely distributed in 3D and by simultaneously recording from the soma, proximal and distal dendrites of neocortical pyramidal cells in behaving mice. PMID:27749836

Mathematic Model of Digital Control System with PID Regulator and Regular Step of Quantization with Information Transfer via the Channel of Plural Access

NASA Astrophysics Data System (ADS)

Abramov, G. V.; Emeljanov, A. E.; Ivashin, A. L.

Theoretical bases for modeling a digital control system with information transfer via the channel of plural access and a regular quantization cycle are submitted. The theory of dynamic systems with random changes of the structure including elements of the Markov random processes theory is used for a mathematical description of a network control system. The characteristics of similar control systems are received. Experimental research of the given control systems is carried out.

Magnet/Hall-Effect Random-Access Memory

NASA Technical Reports Server (NTRS)

Wu, Jiin-Chuan; Stadler, Henry L.; Katti, Romney R.

1991-01-01

In proposed magnet/Hall-effect random-access memory (MHRAM), bits of data stored magnetically in Perm-alloy (or equivalent)-film memory elements and read out by using Hall-effect sensors to detect magnetization. Value of each bit represented by polarity of magnetization. Retains data for indefinite time or until data rewritten. Speed of Hall-effect sensors in MHRAM results in readout times of about 100 nanoseconds. Other characteristics include high immunity to ionizing radiation and storage densities of order 10(Sup6)bits/cm(Sup 2) or more.

System access control study

DOT National Transportation Integrated Search

1974-06-01

The report presents a summary of a study conducted for the Transportation Systems Center of promising access control techniques which are applicable to an aeronautical satellite system. Several frequency division multiple access (FDMA) and time divis...

Full-band TDM-OPDMA for OBI-reduced simultaneous multiple access in a single-wavelength optical access network.

PubMed

Jung, Sun-Young; Kim, Chang-Hun; Han, Sang-Kook

2018-05-14

Simultaneous multiple access (MA) within a single wavelength can increase the data rate and split ratio in a passive optical network while optical beat interference (OBI) becomes serious in the uplink. Previous techniques to reduce OBI were limited by their complexity and lack of extendibility; as well, bandwidth allocation among MA signals is needed for single photo diode (PD) detection. We proposed and experimentally demonstrated full-band optical pulse division multiplexing-based MA (OPDMA) in an optical access network, which can effectively reduce OBI with extendibility and fully utilize frequency resources of optical modulator without bandwidth allocation in a single-wavelength MA.

On board processing for future satellite communications systems: Comparison of FDM, TDM and hybrid accessing schemes

NASA Technical Reports Server (NTRS)

Berk, G.; Jean, P. N.; Rotholz, E.

1982-01-01

Several satellite uplink and downlink accessing schemes for customer premises service are compared. Four conceptual system designs are presented: satellite-routed frequency division multiple access (FDMA), satellite-switched time division multiple access (TDMA), processor-routed TDMA, and frequency-routed TDMA, operating in the 30/20 GHz band. The designs are compared on the basis of estimated satellite weight, system capacity, power consumption, and cost. The systems are analyzed for fixed multibeam coverage of the continental United States. Analysis shows that the system capacity is limited by the available satellite resources and by the terminal size and cost.

False Operation of Static Random Access Memory Cells under Alternating Current Power Supply Voltage Variation

NASA Astrophysics Data System (ADS)

Sawada, Takuya; Takata, Hidehiro; Nii, Koji; Nagata, Makoto

2013-04-01

Static random access memory (SRAM) cores exhibit susceptibility against power supply voltage variation. False operation is investigated among SRAM cells under sinusoidal voltage variation on power lines introduced by direct RF power injection. A standard SRAM core of 16 kbyte in a 90 nm 1.5 V technology is diagnosed with built-in self test and on-die noise monitor techniques. The sensitivity of bit error rate is shown to be high against the frequency of injected voltage variation, while it is not greatly influenced by the difference in frequency and phase against SRAM clocking. It is also observed that the distribution of false bits is substantially random in a cell array.

A random access memory immune to single event upset using a T-Resistor

DOEpatents

Ochoa, A. Jr.

1987-10-28

In a random access memory cell, a resistance ''T'' decoupling network in each leg of the cell reduces random errors caused by the interaction of energetic ions with the semiconductor material forming the cell. The cell comprises two parallel legs each containing a series pair of complementary MOS transistors having a common gate connected to the node between the transistors of the opposite leg. The decoupling network in each leg is formed by a series pair of resistors between the transistors together with a third resistor interconnecting the junction between the pair of resistors and the gate of the transistor pair forming the opposite leg of the cell. 4 figs.

Random access memory immune to single event upset using a T-resistor

DOEpatents

Ochoa, Jr., Agustin

1989-01-01

In a random access memory cell, a resistance "T" decoupling network in each leg of the cell reduces random errors caused by the interaction of energetic ions with the semiconductor material forming the cell. The cell comprises two parallel legs each containing a series pair of complementary MOS transistors having a common gate connected to the node between the transistors of the opposite leg. The decoupling network in each leg is formed by a series pair of resistors between the transistors together with a third resistor interconnecting the junction between the pair of resistors and the gate of the transistor pair forming the opposite leg of the cell.

The Role of Access to Head Start and Quality Ratings for Spanish-Speaking Dual Language Learners’ (DLLs) Participation in Early Childhood Education

PubMed Central

2014-01-01

Data from the Head Start Impact Study (N = 4,442) were used to test for differences between Spanish-speaking Dual Language Learners (DLLs) and monolingual English-speaking children in: (1) Head Start attendance rates when randomly assigned admission; and (2) quality ratings of other early childhood education (ECE) programs attended when not randomly assigned admission to Head Start. Logistic regressions showed that Spanish-speaking DLL children randomly assigned a spot in Head Start were more likely than monolingual-English learners to attend. Further, Spanish-speaking DLLs not randomly assigned a spot in Head Start were more likely to attend higher-quality ECE centers than non-DLL children. Policy implications are discussed, suggesting that, if given access, Spanish-speaking DLL families will take advantage of quality ECE programs. PMID:25018585

Random Telegraph Signal-Like Fluctuation Created by Fowler-Nordheim Stress in Gate Induced Drain Leakage Current of the Saddle Type Dynamic Random Access Memory Cell Transistor

NASA Astrophysics Data System (ADS)

Kim, Heesang; Oh, Byoungchan; Kim, Kyungdo; Cha, Seon-Yong; Jeong, Jae-Goan; Hong, Sung-Joo; Lee, Jong-Ho; Park, Byung-Gook; Shin, Hyungcheol

2010-09-01

We generated traps inside gate oxide in gate-drain overlap region of recess channel type dynamic random access memory (DRAM) cell transistor through Fowler-Nordheim (FN) stress, and observed gate induced drain leakage (GIDL) current both in time domain and in frequency domain. It was found that the trap inside gate oxide could generate random telegraph signal (RTS)-like fluctuation in GIDL current. The characteristics of that fluctuation were similar to those of RTS-like fluctuation in GIDL current observed in the non-stressed device. This result shows the possibility that the trap causing variable retention time (VRT) in DRAM data retention time can be located inside gate oxide like channel RTS of metal-oxide-semiconductor field-effect transistors (MOSFETs).

School Web Sites: Are They Accessible to All?

ERIC Educational Resources Information Center

Wells, Julie A.; Barron, Ann E.

2006-01-01

In 2002, the National Center for Educational Statistics reported that 99% of public schools had Internet access and 86% of those schools had a web site or web page (Kleiner & Lewis, 2003). This study examined accessibility issues on elementary school homepages. Using a random sample of elementary school web sites, the researchers documented…

Study protocol: a randomized controlled trial investigating the effects of a psychosexual training program for adolescents with autism spectrum disorder.

PubMed

Visser, Kirsten; Greaves-Lord, Kirstin; Tick, Nouchka T; Verhulst, Frank C; Maras, Athanasios; van der Vegt, Esther J M

2015-08-28

Previous research shows that adolescents with autism spectrum disorder (ASD) run several risks in their psychosexual development and that these adolescents can have limited access to reliable information on puberty and sexuality, emphasizing the need for specific guidance of adolescents with ASD in their psychosexual development. Few studies have investigated the effects of psychosexual training programs for adolescents with ASD and to date no randomized controlled trials are available to study the effects of psychosexual interventions for this target group. The randomized controlled trial (RCT) described in this study protocol aims to investigate the effects of the Tackling Teenage Training (TTT) program on the psychosexual development of adolescents with ASD. This parallel clinical trial, conducted in the South-West of the Netherlands, has a simple equal randomization design with an intervention and a waiting-list control condition. Two hundred adolescents and their parents participate in this study. We assess the participants in both conditions using self-report as well as parent-report questionnaires at three time points during 1 year: at baseline (T1), post-treatment (T2), and for follow-up (T3). To our knowledge, the current study is the first that uses a randomized controlled design to study the effects of a psychosexual training program for adolescents with ASD. It has a number of methodological strengths, namely a large sample size, a wide range of functionally relevant outcome measures, the use of multiple informants, and a standardized research and intervention protocol. Also some limitations of the described study are identified, for instance not making a comparison between two treatment conditions, and no use of blinded observational measures to investigate the ecological validity of the research results. Dutch Trial Register NTR2860. Registered on 20 April 2011.

Mobile and Accessible Learning for MOOCs

ERIC Educational Resources Information Center

Sharples, Mike; Kloos, Carlos Delgado; Dimitriadis, Yannis; Garlatti, Serge; Specht, Marcus

2015-01-01

Many modern web-based systems provide a "responsive" design that allows material and services to be accessed on mobile and desktop devices, with the aim of providing "ubiquitous access." Besides offering access to learning materials such as podcasts and videos across multiple locations, mobile, wearable and ubiquitous…

Changes in Diet after Introduction of a Full Service Supermarket in a Food Desert

PubMed Central

Dubowitz, Tamara; Ghosh-Dastidar, Madhumita; Cohen, Deborah A.; Beckman, Robin; Steiner, Elizabeth D.; Hunter, Gerald P.; Flórez, Karen R.; Huang, Christina; Vaughan, Christine A.; Sloan, Jennifer C.; Zenk, Shannon N.; Cummins, Steven; Collins, Rebecca L.

2016-01-01

Placing full-service supermarkets in food deserts (areas with limited access to healthy foods) has been proposed as an important policy strategy to confront inequalities in healthy food access. Capitalizing on a natural experiment, we enrolled n=1,372 randomly selected households from two comparable neighborhoods, one of which received a full-service supermarket in 2013. We looked at the impact on residents’ diet, perceived access to healthy foods and satisfaction with one’s neighborhood as a place to live. Baseline data was collected in 2011, and follow-up in 2014. Relative to the comparison neighborhood, we found a net positive change in the intervention neighborhood in overall dietary quality, total kilocalories, added sugars, and solid fats, alcohol and added sugars (SoFAAS). However, we did not observe differential improvement in fruit and vegetable intake, whole grain consumption or body mass index (BMI). Regular users of the new supermarket had significantly improved perceived access to healthy foods compared to others, but use of the new supermarket was not related to dietary changes or to improvements with neighborhood satisfaction. Our study is the first to our knowledge to have found significant improvements in multiple dietary outcomes and neighborhood satisfaction among residents of a food desert, following the opening of a supermarket. Our study supports the Healthy Food Financing Initiative and other policies that incentivize food retail venues to locate in food deserts, but we recommend further efforts proceed with caution until research has clarified the mechanisms through which diet is improved and associations with weight status/obesity have been observed. PMID:26526243

Study of spread spectrum multiple access systems for satellite communications with overlay on current services

NASA Technical Reports Server (NTRS)

Ha, Tri T.; Pratt, Timothy

1989-01-01

The feasibility of using spread spectrum techniques to provide a low-cost multiple access system for a very large number of low data terminals was investigated. Two applications of spread spectrum technology to very small aperture terminal (VSAT) satellite communication networks are presented. Two spread spectrum multiple access systems which use a form of noncoherent M-ary FSK (MFSK) as the primary modulation are described and the throughput analyzed. The analysis considers such factors as satellite power constraints and adjacent satellite interference. Also considered is the effect of on-board processing on the multiple access efficiency and the feasibility of overlaying low data rate spread spectrum signals on existing satellite traffic as a form of frequency reuse is investigated. The use of chirp is examined for spread spectrum communications. In a chirp communication system, each data bit is converted into one or more up or down sweeps of frequency, which spread the RF energy across a broad range of frequencies. Several different forms of chirp communication systems are considered, and a multiple-chirp coded system is proposed for overlay service. The mutual interference problem is examined in detail and a performance analysis undertaken for the case of a chirp data channel overlaid on a video channel.

Optimal Resource Allocation for NOMA-TDMA Scheme with α-Fairness in Industrial Internet of Things.

PubMed

Sun, Yanjing; Guo, Yiyu; Li, Song; Wu, Dapeng; Wang, Bin

2018-05-15

In this paper, a joint non-orthogonal multiple access and time division multiple access (NOMA-TDMA) scheme is proposed in Industrial Internet of Things (IIoT), which allowed multiple sensors to transmit in the same time-frequency resource block using NOMA. The user scheduling, time slot allocation, and power control are jointly optimized in order to maximize the system α -fair utility under transmit power constraint and minimum rate constraint. The optimization problem is nonconvex because of the fractional objective function and the nonconvex constraints. To deal with the original problem, we firstly convert the objective function in the optimization problem into a difference of two convex functions (D.C.) form, and then propose a NOMA-TDMA-DC algorithm to exploit the global optimum. Numerical results show that the NOMA-TDMA scheme significantly outperforms the traditional orthogonal multiple access scheme in terms of both spectral efficiency and user fairness.

Sharing Resources In Mobile/Satellite Communications

NASA Technical Reports Server (NTRS)

Yan, Tsun-Yee; Sue, Miles K.

1992-01-01

Report presents preliminary theoretical analysis of several alternative schemes for allocation of satellite resource among terrestrial subscribers of landmobile/satellite communication system. Demand-access and random-access approaches under code-division and frequency-division concepts compared.

Mathematics of gravitational lensing: multiple imaging and magnification

NASA Astrophysics Data System (ADS)

Petters, A. O.; Werner, M. C.

2010-09-01

The mathematical theory of gravitational lensing has revealed many generic and global properties. Beginning with multiple imaging, we review Morse-theoretic image counting formulas and lower bound results, and complex-algebraic upper bounds in the case of single and multiple lens planes. We discuss recent advances in the mathematics of stochastic lensing, discussing a general formula for the global expected number of minimum lensed images as well as asymptotic formulas for the probability densities of the microlensing random time delay functions, random lensing maps, and random shear, and an asymptotic expression for the global expected number of micro-minima. Multiple imaging in optical geometry and a spacetime setting are treated. We review global magnification relation results for model-dependent scenarios and cover recent developments on universal local magnification relations for higher order caustics.

Controllable Organic Resistive Switching Achieved by One-Step Integration of Cone-Shaped Contact.

PubMed

Ling, Haifeng; Yi, Mingdong; Nagai, Masaru; Xie, Linghai; Wang, Laiyuan; Hu, Bo; Huang, Wei

2017-09-01

Conductive filaments (CFs)-based resistive random access memory possesses the ability of scaling down to sub-nanoscale with high-density integration architecture, making it the most promising nanoelectronic technology for reclaiming Moore's law. Compared with the extensive study in inorganic switching medium, the scientific challenge now is to understand the growth kinetics of nanoscale CFs in organic polymers, aiming to achieve controllable switching characteristics toward flexible and reliable nonvolatile organic memory. Here, this paper systematically investigates the resistive switching (RS) behaviors based on a widely adopted vertical architecture of Al/organic/indium-tin-oxide (ITO), with poly(9-vinylcarbazole) as the case study. A nanoscale Al filament with a dynamic-gap zone (DGZ) is directly observed using in situ scanning transmission electron microscopy (STEM) , which demonstrates that the RS behaviors are related to the random formation of spliced filaments consisting of Al and oxygen vacancy dual conductive channels growing through carbazole groups. The randomicity of the filament formation can be depressed by introducing a cone-shaped contact via a one-step integration method. The conical electrode can effectively shorten the DGZ and enhance the localized electric field, thus reducing the switching voltage and improving the RS uniformity. This study provides a deeper insight of the multiple filamentary mechanisms for organic RS effect. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Impact of Preoperative α-Adrenergic Antagonists on Ureteral Access Sheath Insertion Force and the Upper Limit of Force Required to Avoid Ureteral Mucosal Injury: A Randomized Controlled Study.

PubMed

Koo, Kyo Chul; Yoon, Jun-Ho; Park, No-Cheol; Lee, Hye Sun; Ahn, Hyun Kyu; Lee, Kwang Suk; Kim, Do Kyung; Cho, Kang Su; Chung, Byung Ha; Hong, Chang Hee

2018-06-01

Excessive bulking force during primary access of the ureteral access sheath may induce ureteral injury. We investigated the efficacy of preoperative α-blockade to reduce ureteral access sheath insertion force and determine the upper limit required to avoid ureteral injury. In this randomized controlled trial 135 patients from a single institution who had ureteropelvic junction or renal pelvis stones and were scheduled to undergo retrograde intrarenal surgery were prospectively enrolled from December 2015 to January 2017. Of the patients 41 and 42 were randomly assigned to the control and experimental groups, respectively. The experimental group received α-blockade preoperatively. The 21 patients who were pre-stented were assessed separately. We developed a homemade device to measure maximal ureteral access sheath insertion force. Our ureteral access sheath insertion force measurement device showed excellent reproducibility. Higher insertion velocity resulted in greater maximal sheath insertion force. Maximal insertion force in the α-blockade group was significantly lower than in the control group at the ureterovesical junction (p = 0.008) and the proximal ureter (p = 0.036). Maximal insertion force in the α-blockade group was comparable to that in pre-stented patients. Female patients and patients 70 years old or older showed a lower maximal ureteral access sheath insertion force than their counterparts. The rate of grade 2 or greater ureteral injury was lower in the α-blockade group than in controls (p = 0.038). No injury occurred in any case in which ureteral access sheath insertion force did not exceed 600 G. Preoperative α-blockade and slow sheath placement may reduce maximal ureteral access sheath insertion force. If the force exceeds 600 G, a smaller diameter sheath may be an alternative. Alternatively the procedure can be terminated and followed later by pre-stented retrograde intrarenal surgery. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

A multi-level intervention in worksites to increase fruit and vegetable access and intake: Rationale, design and methods of the 'Good to Go' cluster randomized trial.

PubMed

Risica, Patricia M; Gorham, Gemma; Dionne, Laura; Nardi, William; Ng, Doug; Middler, Reese; Mello, Jennifer; Akpolat, Rahmet; Gettens, Katelyn; Gans, Kim M

2018-02-01

Fruit and vegetable (F&V) consumption is an important contributor to chronic disease prevention. However, most Americans do not eat adequate amounts. The worksite is an advantageous setting to reach large, diverse segments of the population with interventions to increase F&V intake, but research gaps exist. No studies have evaluated the implementation of mobile F&V markets at worksites nor compared the effectiveness of such markets with or without nutrition education. This paper describes the protocol for Good to Go (GTG), a cluster randomized trial to evaluate F&V intake change in employees from worksites randomized into three experimental arms: discount, fresh F&V markets (Access Only arm); markets plus educational components including campaigns, cooking demonstrations, videos, newsletters, and a web site (Access Plus arm); and an attention placebo comparison intervention on physical activity and stress reduction (Comparison). Secondary aims include: 1) Process evaluation to determine costs, reach, fidelity, and dose as well as the relationship of these variables with changes in F&V intake; 2) Applying a mediating variable framework to examine relationships of psychosocial factors/determinants with changes in F&V consumption; and 3) Cost effectiveness analysis of the different intervention arms. The GTG study will fill important research gaps in the field by implementing a rigorous cluster randomized trial to evaluate the efficacy of an innovative environmental intervention providing access and availability to F&V at the worksite and whether this access intervention is further enhanced by accompanying educational interventions. GTG will provide an important contribution to public health research and practice. Trial registration number NCT02729675, ClinicalTrials.gov. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

A multi-level intervention in worksites to increase fruit and vegetable access and intake: Rationale, design and methods of the ‘Good to Go’ cluster randomized trial

PubMed Central

Risica, Patricia M.; Gorham, Gemma; Dionne, Laura; Nardi, William; Ng, Doug; Middler, Reese; Mello, Jennifer; Akpolat, Rahmet; Gettens, Katelyn; Gans, Kim M.

2018-01-01

Background Fruit and vegetable (F&V) consumption is an important contributor to chronic disease prevention. However, most Americans do not eat adequate amounts. The worksite is an advantageous setting to reach large, diverse segments of the population with interventions to increase F&V intake, but research gaps exist. No studies have evaluated the implementation of mobile F&V markets at worksites nor compared the effectiveness of such markets with or without nutrition education. Methods This paper describes the protocol for Good to Go (GTG), a cluster randomized trial to evaluate F&V intake change in employees from worksites randomized into three experimental arms: discount, fresh F&V markets (Access Only arm); markets plus educational components including campaigns, cooking demonstrations, videos, newsletters, and a web site (Access Plus arm); and an attention placebo comparison intervention on physical activity and stress reduction (Comparison). Secondary aims include: 1) Process evaluation to determine costs, reach, fidelity, and dose as well as the relationship of these variables with changes in F&V intake; 2) Applying a mediating variable framework to examine relationships of psychosocial factors/determinants with changes in F&V consumption; and 3) Cost effectiveness analysis of the different intervention arms. Discussion The GTG study will fill important research gaps in the field by implementing a rigorous cluster randomized trial to evaluate the efficacy of an innovative environmental intervention providing access and availability to F&V at the worksite and whether this access intervention is further enhanced by accompanying educational interventions. GTG will provide an important contribution to public health research and practice. Trial registration number NCT02729675, ClinicalTrials.gov PMID:29242108

Nonparametric estimation of the heterogeneity of a random medium using compound Poisson process modeling of wave multiple scattering.

PubMed

Le Bihan, Nicolas; Margerin, Ludovic

2009-07-01

In this paper, we present a nonparametric method to estimate the heterogeneity of a random medium from the angular distribution of intensity of waves transmitted through a slab of random material. Our approach is based on the modeling of forward multiple scattering using compound Poisson processes on compact Lie groups. The estimation technique is validated through numerical simulations based on radiative transfer theory.

Quantum Optimal Multiple Assignment Scheme for Realizing General Access Structure of Secret Sharing

NASA Astrophysics Data System (ADS)

Matsumoto, Ryutaroh

The multiple assignment scheme is to assign one or more shares to single participant so that any kind of access structure can be realized by classical secret sharing schemes. We propose its quantum version including ramp secret sharing schemes. Then we propose an integer optimization approach to minimize the average share size.

Performance enhancement of optical code-division multiple-access systems using transposed modified Walsh code

NASA Astrophysics Data System (ADS)

Sikder, Somali; Ghosh, Shila

2018-02-01

This paper presents the construction of unipolar transposed modified Walsh code (TMWC) and analysis of its performance in optical code-division multiple-access (OCDMA) systems. Specifically, the signal-to-noise ratio, bit error rate (BER), cardinality, and spectral efficiency were investigated. The theoretical analysis demonstrated that the wavelength-hopping time-spreading system using TMWC was robust against multiple-access interference and more spectrally efficient than systems using other existing OCDMA codes. In particular, the spectral efficiency was calculated to be 1.0370 when TMWC of weight 3 was employed. The BER and eye pattern for the designed TMWC were also successfully obtained using OptiSystem simulation software. The results indicate that the proposed code design is promising for enhancing network capacity.

On-Chip Fluorescence Switching System for Constructing a Rewritable Random Access Data Storage Device.

PubMed

Nguyen, Hoang Hiep; Park, Jeho; Hwang, Seungwoo; Kwon, Oh Seok; Lee, Chang-Soo; Shin, Yong-Beom; Ha, Tai Hwan; Kim, Moonil

2018-01-10

We report the development of on-chip fluorescence switching system based on DNA strand displacement and DNA hybridization for the construction of a rewritable and randomly accessible data storage device. In this study, the feasibility and potential effectiveness of our proposed system was evaluated with a series of wet experiments involving 40 bits (5 bytes) of data encoding a 5-charactered text (KRIBB). Also, a flexible data rewriting function was achieved by converting fluorescence signals between "ON" and "OFF" through DNA strand displacement and hybridization events. In addition, the proposed system was successfully validated on a microfluidic chip which could further facilitate the encoding and decoding process of data. To the best of our knowledge, this is the first report on the use of DNA hybridization and DNA strand displacement in the field of data storage devices. Taken together, our results demonstrated that DNA-based fluorescence switching could be applicable to construct a rewritable and randomly accessible data storage device through controllable DNA manipulations.

Longitudinal Associations Between Observed and Perceived Neighborhood Food Availability and Body Mass Index in a Multiethnic Urban Sample.

PubMed

Zenk, Shannon N; Mentz, Graciela; Schulz, Amy J; Johnson-Lawrence, Vicki; Gaines, Causandra R

2017-02-01

Blacks, Hispanics, and women of lower socioeconomic status tend to have a higher risk of obesity. Numerous studies over the past decade examined the role of the neighborhood food environment in body weight. However, few were longitudinal. This longitudinal study examined whether multiple measures of neighborhood food availability were associated with body mass index (BMI) in a predominately Black and Hispanic adult sample living in low- to moderate-income urban neighborhoods. This longitudinal study used two waves of data (2002, 2008), including interviewer-measured height and weight, from a community survey of adults ( n = 219). In both 2002 and 2008, multiple measures characterized neighborhood food availability: GIS-derived availability of retail food outlets (large grocery store, small grocery store, convenience store, liquor stores), observed fruit and vegetable availability (count of stores selling 10 or more fresh fruit or vegetable varieties), and perceived fruit and vegetable access. Random intercept models estimated multivariable associations, controlling for individual-level demographics and neighborhood median household income. Small grocery store availability was associated with 1.22-unit increase in BMI ( p = .047), while each unit increase in perceived fruit and vegetable access was associated with a 0.69-unit decrease in BMI ( p = .055). BMI was not associated with large grocery store, convenience store, or liquor store availability, or with observed fruit and vegetable availability. Findings suggest that improving the neighborhood food environment, particularly at small grocery stores, may help urban residents living in low- to moderate-income neighborhoods achieve healthier body weights over time.

Family Characteristics and Children's Receipt of Autism Services in Low-Resourced Families.

PubMed

Karp, Elizabeth A; Dudovitz, Rebecca; Nelson, Bergen B; Shih, Wendy; Gulsrud, Amanda; Orlich, Felice; Colombi, Costanza; Kuo, Alice A

2018-04-01

Parents of children with autism spectrum disorder (ASD) face competing demands when caring for their child and fulfilling family commitments. It remains unknown whether family obligations and parental stress might decrease the use of intervention services for young children with ASD. The current study is a secondary analysis of baseline date from a published randomized control trial with 147 low-resourced caregiver-child dyads. Demographic information, data on service use, maternal employment, parent's perception of their child's development, and parental stress were collected for primary caregivers of 2- to 5-year-old children with ASD from 5 sites. Multiple logistic regressions of accessing any intervention services or more than 1 services on familial characteristics were performed, controlling for demographic and contextual variables. Twenty-five percent of children were receiving no intervention service; 26% were receiving 1 service; and 49% were receiving 2 or more services. Perceived developmental delay and not having a sibling in the home were associated with higher odds of receiving intervention services. Children were more likely to receive more than 1 service if their parents had at least a college education and low levels of stress. Factors including perceived developmental level, parental stress, and caring for siblings may play a role in accessing services for children with ASD. Results reveal that competing family needs may be barriers to service use. Mothers of children with ASD with multiple children in the home, low levels of education, and high levels of stress may need additional supports or alternative service delivery models. Copyright © 2018 by the American Academy of Pediatrics.

Rural providers' access to online resources: a randomized controlled trial

PubMed Central

Hall, Laura J.; McElfresh, Karen R.; Warner, Teddy D.; Stromberg, Tiffany L.; Trost, Jaren; Jelinek, Devin A.

2016-01-01

Objective The research determined the usage and satisfaction levels with one of two point-of-care (PoC) resources among health care providers in a rural state. Methods In this randomized controlled trial, twenty-eight health care providers in rural areas were stratified by occupation and region, then randomized into either the DynaMed or the AccessMedicine study arm. Study participants were physicians, physician assistants, and nurses. A pre- and post-study survey measured participants' attitudes toward different information resources and their information-seeking activities. Medical student investigators provided training and technical support for participants. Data analyses consisted of analysis of variance (ANOVA), paired t tests, and Cohen's d statistic to compare pre- and post-study effects sizes. Results Participants in both the DynaMed and the AccessMedicine arms of the study reported increased satisfaction with their respective PoC resource, as expected. Participants in both arms also reported that they saved time in finding needed information. At baseline, both arms reported too little information available, which increased to “about right amounts of information” at the completion of the study. DynaMed users reported a Cohen's d increase of +1.50 compared to AccessMedicine users' reported use of 0.82. DynaMed users reported d2 satisfaction increases of 9.48 versus AccessMedicine satisfaction increases of 0.59 using a Cohen's d. Conclusion Participants in the DynaMed arm of the study used this clinically oriented PoC more heavily than the users of the textbook-based AccessMedicine. In terms of user satisfaction, DynaMed users reported higher levels of satisfaction than the users of AccessMedicine. PMID:26807050

Predictors for the Number of Warning Information Sources During Tornadoes.

PubMed

Cong, Zhen; Luo, Jianjun; Liang, Daan; Nejat, Ali

2017-04-01

People may receive tornado warnings from multiple information sources, but little is known about factors that affect the number of warning information sources (WISs). This study examined predictors for the number of WISs with a telephone survey on randomly sampled residents in Tuscaloosa, Alabama, and Joplin, Missouri, approximately 1 year after both cities were struck by violent tornadoes (EF4 and EF5) in 2011. The survey included 1006 finished interviews and the working sample included 903 respondents. Poisson regression and Zero-Inflated Poisson regression showed that older age and having an emergency plan predicted more WISs in both cities. Education, marital status, and gender affected the possibilities of receiving warnings and the number of WISs either in Joplin or in Tuscaloosa. The findings suggest that social disparity affects the access to warnings not only with respect to the likelihood of receiving any warnings but also with respect to the number of WISs. In addition, historical and social contexts are important for examining predictors for the number of WISs. We recommend that the number of WISs should be regarded as an important measure to evaluate access to warnings in addition to the likelihood of receiving warnings. (Disaster Med Public Health Preparedness. 2017;11:168-172).

Media and youth: access, exposure, and privatization.

PubMed

Roberts, D F

2000-08-01

To describe U.S. youth's access and exposure to the full array of media, as well as the social contexts in which media exposure occurs. A cross-sectional national random sample of 2065 adolescents aged 8 through 18 years, including oversamples of African-American and Hispanic youth, completed questionnaires about use of television, videotapes, movies, computers, video games, radio, compact discs, tape players, books, newspapers, and magazines. U.S. youngsters are immersed in media. Most households contain most media (computers and video game systems are the exception); the majority of youth have their own personal media. The average youth devotes 6 3/4 h to media; simultaneous use of multiple media increases exposure to 8 h of media messages daily. Overall, media exposure and exposure to individual media vary as a function of age, gender, race/ethnicity, and family socioeconomic level. Television remains the dominant medium. About one-half of the youth sampled uses a computer daily. A substantial proportion of children's and adolescents' media use occurs in the absence of parents. American youth devote more time to media than to any other waking activity, as much as one-third of each day. This demands increased parental attention and research into the effects of such extensive exposure.

Is physician-patient concordance associated with greater trust for women of low socioeconomic status?

PubMed

Scheid, Teresa L; Smith, Galen H

2017-07-01

The authors examined the association between physician-patient concordance and patient trust for low socio-economic status women who were enrolled in Medicaid case management. The data were collected from October 2006 through March 2007 from a stratified random sample of 2,815 adult beneficiaries enrolled in North Carolina Medicaid's primary care case management delivery system. We limited our analyses to women enrolled in primary care, hence controlling for gender and social class as well as access to care. We were also able to control for the availability of minority providers. The findings revealed that the enrollee's race, education, and experiences seeking help with their health providers were significantly related to patient's trust of their physicians. Neither race concordance nor gender concordance improved trust. This may be because relatively few minority providers were included in the sample. These results extend research on physician-patient concordance by examining the relationship of both racial and gender concordance with patient trust while controlling for access and social class. Research on physician-patient concordance needs to account for multiple measures of social status, as well as differences in culture and communication styles between physicians and their patients.

Why do boys eat less fruit and vegetables than girls?

PubMed

Bere, Elling; Brug, Johannes; Klepp, Knut-Inge

2008-03-01

To explore why boys eat less fruit and vegetables (F&V) than girls, using longitudinal data following pupils from the age of 12.5 to 15.5 years, including perceived accessibility, modelling, intention, preferences, self-efficacy and knowledge of recommendations as potential mediators. A longitudinal study, based on data collected among the control schools within the intervention project 'Fruits and Vegetables Make the Marks'. This sample contains 896 6th and 7th graders from 20 randomly selected elementary schools within two Norwegian counties. Questionnaires were administered in May 2002 and May 2005 (when the participants were in 9th and 10th grade in 18 secondary elementary schools). In single mediation analyses all determinants mediated parts of the gender difference, but only preferences decreased the gender difference to a level below statistical significance. Preferences alone explained 81% of the gender difference. In the multiple mediation analyses, the six mediators together explained 91% of the gender difference, but only preferences and perceived accessibility contributed uniquely to the explanation, with 25% and 10% respectively. Preference appears as the strongest mediator of the difference in F&V intakes between boys and girls. Further research should explore why girls like F&V more than boys.

Rural-urban analyses of health-related quality of life among people with multiple sclerosis.

PubMed

Buchanan, Robert J; Zhu, Li; Schiffer, Randolph; Radin, Dagmar; James, Wesley

2008-01-01

Health-related quality of life (HRQOL) is a multi-dimensional construct including aspects of life quality or function that are affected by physical health and symptoms, psychosocial factors, and psychiatric conditions. HRQOL gives a broader measure of the burden of disease than physical impairment or disability levels. To identify factors associated with HRQOL among people with multiple sclerosis (MS) utilizing the SF-8 Health Survey. Data presented in this study were collected in a survey of 1,518 people with MS living in all 50 states. The survey sample was randomly selected from the database of the National Multiple Sclerosis Society, using ZIP codes to recruit the survey sample. A multiple linear regression model was employed to analyze the survey data, with the Physical Component Summary and the Mental Component Summary of the SF-8 the dependent variables. Independent variables were demographic characteristics, MS-disease characteristics, and health services utilized. People with MS in rural areas tended to report lower physically related HRQOL. Worsening MS symptoms were associated with reduced physical and mental dimensions of HRQOL. In addition, people with MS who received a diagnosis of depression tended to have reduced physical and mental dimensions of HRQOL. Receiving MS care at an MS clinic was associated with better physically related HRQOL, while having a neurologist as principal care physician was associated with better mental-related HRQOL. The challenge is to increase the access that people living with MS in rural areas have to MS-focused specialty care.

Vortex-Core Reversal Dynamics: Towards Vortex Random Access Memory

NASA Astrophysics Data System (ADS)

Kim, Sang-Koog

2011-03-01

An energy-efficient, ultrahigh-density, ultrafast, and nonvolatile solid-state universal memory is a long-held dream in the field of information-storage technology. The magnetic random access memory (MRAM) along with a spin-transfer-torque switching mechanism is a strong candidate-means of realizing that dream, given its nonvolatility, infinite endurance, and fast random access. Magnetic vortices in patterned soft magnetic dots promise ground-breaking applications in information-storage devices, owing to the very stable twofold ground states of either their upward or downward core magnetization orientation and plausible core switching by in-plane alternating magnetic fields or spin-polarized currents. However, two technologically most important but very challenging issues --- low-power recording and reliable selection of each memory cell with already existing cross-point architectures --- have not yet been resolved for the basic operations in information storage, that is, writing (recording) and readout. Here, we experimentally demonstrate a magnetic vortex random access memory (VRAM) in the basic cross-point architecture. This unique VRAM offers reliable cell selection and low-power-consumption control of switching of out-of-plane core magnetizations using specially designed rotating magnetic fields generated by two orthogonal and unipolar Gaussian-pulse currents along with optimized pulse width and time delay. Our achievement of a new device based on a new material, that is, a medium composed of patterned vortex-state disks, together with the new physics on ultrafast vortex-core switching dynamics, can stimulate further fruitful research on MRAMs that are based on vortex-state dot arrays.

Program for the analysis of time series. [by means of fast Fourier transform algorithm

NASA Technical Reports Server (NTRS)

Brown, T. J.; Brown, C. G.; Hardin, J. C.

1974-01-01

A digital computer program for the Fourier analysis of discrete time data is described. The program was designed to handle multiple channels of digitized data on general purpose computer systems. It is written, primarily, in a version of FORTRAN 2 currently in use on CDC 6000 series computers. Some small portions are written in CDC COMPASS, an assembler level code. However, functional descriptions of these portions are provided so that the program may be adapted for use on any facility possessing a FORTRAN compiler and random-access capability. Properly formatted digital data are windowed and analyzed by means of a fast Fourier transform algorithm to generate the following functions: (1) auto and/or cross power spectra, (2) autocorrelations and/or cross correlations, (3) Fourier coefficients, (4) coherence functions, (5) transfer functions, and (6) histograms.

ASSISTments Dataset from Multiple Randomized Controlled Experiments

ERIC Educational Resources Information Center

Selent, Douglas; Patikorn, Thanaporn; Heffernan, Neil

2016-01-01

In this paper, we present a dataset consisting of data generated from 22 previously and currently running randomized controlled experiments inside the ASSISTments online learning platform. This dataset provides data mining opportunities for researchers to analyze ASSISTments data in a convenient format across multiple experiments at the same time.…

An access technology delivery protocol for children with severe and multiple disabilities: a case demonstration.

PubMed

Mumford, Leslie; Lam, Rachel; Wright, Virginia; Chau, Tom

2014-08-01

This study applied response efficiency theory to create the Access Technology Delivery Protocol (ATDP), a child and family-centred collaborative approach to the implementation of access technologies. We conducted a descriptive, mixed methods case study to demonstrate the ATDP method with a 12-year-old boy with no reliable means of access to an external device. Evaluations of response efficiency, satisfaction, goal attainment, technology use and participation were made after 8 and 16 weeks of training with a custom smile-based access technology. At the 16 week mark, the new access technology offered better response quality; teacher satisfaction was high; average technology usage was 3-4 times per week for up to 1 h each time; switch sensitivity and specificity reached 78% and 64%, respectively, and participation scores increased by 38%. This case supports further development and testing of the ATDP with additional children with multiple or severe disabilities.

A subjective scheduler for subjective dedicated networks

NASA Astrophysics Data System (ADS)

Suherman; Fakhrizal, Said Reza; Al-Akaidi, Marwan

2017-09-01

Multiple access technique is one of important techniques within medium access layer in TCP/IP protocol stack. Each network technology implements the selected access method. Priority can be implemented in those methods to differentiate services. Some internet networks are dedicated for specific purpose. Education browsing or tutorial video accesses are preferred in a library hotspot, while entertainment and sport contents could be subjects of limitation. Current solution may use IP address filter or access list. This paper proposes subjective properties of users or applications are used for priority determination in multiple access techniques. The NS-2 simulator is employed to evaluate the method. A video surveillance network using WiMAX is chosen as the object. Subjective priority is implemented on WiMAX scheduler based on traffic properties. Three different traffic sources from monitoring video: palace, park, and market are evaluated. The proposed subjective scheduler prioritizes palace monitoring video that results better quality, xx dB than the later monitoring spots.

Scalable Lunar Surface Networks and Adaptive Orbit Access

NASA Technical Reports Server (NTRS)

Wang, Xudong

2015-01-01

Teranovi Technologies, Inc., has developed innovative network architecture, protocols, and algorithms for both lunar surface and orbit access networks. A key component of the overall architecture is a medium access control (MAC) protocol that includes a novel mechanism of overlaying time division multiple access (TDMA) and carrier sense multiple access with collision avoidance (CSMA/CA), ensuring scalable throughput and quality of service. The new MAC protocol is compatible with legacy Institute of Electrical and Electronics Engineers (IEEE) 802.11 networks. Advanced features include efficiency power management, adaptive channel width adjustment, and error control capability. A hybrid routing protocol combines the advantages of ad hoc on-demand distance vector (AODV) routing and disruption/delay-tolerant network (DTN) routing. Performance is significantly better than AODV or DTN and will be particularly effective for wireless networks with intermittent links, such as lunar and planetary surface networks and orbit access networks.

The Incremental Validity of the MMPI-2: When Does Therapist Access Not Enhance Treatment Outcome?

ERIC Educational Resources Information Center

Lima, Elizabeth N.; Stanley, Sheila; Kaboski, Beth; Reitzel, Lorraine R.; Richey, Anthony; Castro, Yezzennya; Williams, Foluso M.; Tannenbaum, Kendra R.; Stellrecht, Nadia E.; Jakobsons, Lara J.; Wingate, LaRicka R.; Joiner, Thomas E.

2005-01-01

The present study examined whether therapist access to the Minnesota Multiphasic Personality Inventory (MMPI-2) predicted favorable treatment outcome, above and beyond other assessment measures. A manipulated assessment design was used, in which patients were randomly assigned either to a group in which therapists had access to their MMPI-2 data…

Program Retrieval/Dissemination: A Solid State Random Access System.

ERIC Educational Resources Information Center

Weeks, Walter O., Jr.

The trend toward greater flexibility in educational methods has led to a need for better and more rapid access to a variety of aural and audiovisual resource materials. This in turn has demanded the development of a flexible, reliable system of hardware designed to aid existing distribution methods in providing such access. The system must be…

77 FR 25994 - Notice of Proposed Information Collection Requests; Institute of Education Sciences; Pell Grant...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-02

... will have expanded access to Pell grants; or (2) a control group, which will not have access. Within both substudies, the treatment group will be very similar to the control at the time of random... between treatment and control group members can then be attributed to Pell grant access. The first...

A multiple imputation strategy for sequential multiple assignment randomized trials

PubMed Central

Shortreed, Susan M.; Laber, Eric; Stroup, T. Scott; Pineau, Joelle; Murphy, Susan A.

2014-01-01

Sequential multiple assignment randomized trials (SMARTs) are increasingly being used to inform clinical and intervention science. In a SMART, each patient is repeatedly randomized over time. Each randomization occurs at a critical decision point in the treatment course. These critical decision points often correspond to milestones in the disease process or other changes in a patient’s health status. Thus, the timing and number of randomizations may vary across patients and depend on evolving patient-specific information. This presents unique challenges when analyzing data from a SMART in the presence of missing data. This paper presents the first comprehensive discussion of missing data issues typical of SMART studies: we describe five specific challenges, and propose a flexible imputation strategy to facilitate valid statistical estimation and inference using incomplete data from a SMART. To illustrate these contributions, we consider data from the Clinical Antipsychotic Trial of Intervention and Effectiveness (CATIE), one of the most well-known SMARTs to date. PMID:24919867

Interstage Outcomes in Infants With Single Ventricle Heart Disease Comparing Home Monitoring Technology to Three-Ring Binder Documentation: A Randomized Crossover Study.

PubMed

Bingler, Michael; Erickson, Lori A; Reid, Kimberly J; Lee, Brian; O'Brien, James; Apperson, Johnathan; Goggin, Kathy; Shirali, Girish

2018-05-01

Interstage outcomes for infants with single ventricle remain suboptimal. We have previously described a tablet PC-based platform Cardiac High Acuity Monitoring Program (CHAMP) for remote monitoring which provides immediate access to data, videos, and instant alerts to our single ventricle care team. This study compares traditional three-ring binder monitoring (Binder) to CHAMP using a randomized crossover design to evaluate mortality, resource utilization, and caregiver experience. At discharge, all single ventricle infants were monitored using Binder and randomized to receive CHAMP at either one or two months postdischarge. One month after randomization, caregivers could choose either Binder or CHAMP for the remainder of the interstage period. Caregivers experience was recorded using surveys. Enrollment included 31 single ventricle infants from May 2014 to June 2015. There was no interstage mortality over 4,911 total interstage days (median: 144/patient). Of 73 readmissions, 45 were unplanned. Of the initial 23 unplanned readmissions, 13 were found to have been based on data obtained exclusively through CHAMP (as instant alerts or based on data review) rather than caregiver concerns. Due to concerns regarding patient safety, additional enrollment was stopped. The CHAMP use was associated with significantly fewer unplanned intensive care unit days/100 interstage days, shorter delays in care, lower resource utilization at readmissions, and lower incidence of interstage growth failure and was preferred by a majority of caregivers. These findings suggest that CHAMP may offer benefits over Binder (improved interstage outcomes, delays in care, and caregiver experience). These findings should be tested across multiple centers in larger populations.

Random matrices and condensation into multiple states

NASA Astrophysics Data System (ADS)

Sadeghi, Sina; Engel, Andreas

2018-03-01

In the present work, we employ methods from statistical mechanics of disordered systems to investigate static properties of condensation into multiple states in a general framework. We aim at showing how typical properties of random interaction matrices play a vital role in manifesting the statistics of condensate states. In particular, an analytical expression for the fraction of condensate states in the thermodynamic limit is provided that confirms the result of the mean number of coexisting species in a random tournament game. We also study the interplay between the condensation problem and zero-sum games with correlated random payoff matrices.

A Randomized Controlled Trial Evaluating Efficacy of Promoting a Home-Based HIV Self-Testing with Online Counseling on Increasing HIV Testing Among Men Who Have Sex with Men.

PubMed

Wang, Zixin; Lau, Joseph T F; Ip, Mary; Ho, Shara P Y; Mo, Phoenix K H; Latkin, Carl; Ma, Yee Ling; Kim, Yoona

2018-01-01

We developed an innovative home-based HIV self-testing (HIVST) service that included mailing of a free HIVST kit, and providing online real-time instructions and pre-test/post-test counseling (HIVST-OIC). The present parallel-group and non-blinded randomized controlled trial was conducted to evaluate the efficacy of promoting HIVST-OIC in increasing HIV testing rate among 430 men who have sex with men (MSM), with access to online live-chat applications in Hong Kong. At month 6, as compared to the control group, the intervention group reported significantly higher prevalence of HIV testing of any type (89.8 vs. 50.7%; relative risk (RR): 1.77; p < 0.001). Among those who have taken up any HIV testing in the last six months, significant between-group difference was found in multiple male sex partnerships (34.2 vs. 47.7%, RR: 0.72; p = 0.021). HIVST-OIC has a strong potential in increasing prevalence of HIV testing and reducing sexual risk behaviors. Implementation research is warranted.

Effects of Home Access to Active Videogames on Child Self-Esteem, Enjoyment of Physical Activity, and Anxiety Related to Electronic Games: Results from a Randomized Controlled Trial.

PubMed

Abbott, Rebecca A; Smith, Anne J; Howie, Erin K; Pollock, Clare; Straker, Leon

2014-08-01

Active-input videogames could provide a useful conduit for increasing physical activity by improving a child's self-confidence, physical activity enjoyment, and reducing anxiety. Therefore this study evaluated the impact of (a) the removal of home access to traditional electronic games or (b) their replacement with active-input videogames, on child self-perception, enjoyment of physical activity, and electronic game use anxiety. This was a crossover, randomized controlled trial, conducted over a 6-month period in participants' family homes in metropolitan Perth, Australia, from 2007 to 2010. Children 10-12 years old were recruited through school and community media. Of 210 children who were eligible, 74 met inclusion criteria, and 8 withdrew, leaving 66 children (33 girls) for analysis. A counterbalanced randomized order of three conditions sustained for 8 weeks each: No home access to electronic games, home access to traditional electronic games, and home access to active-input electronic games. Perception of self-esteem (Harter's Self Perception Profile for Children), enjoyment of physical activity (Physical Activity Enjoyment Scale questionnaire), and anxiety toward electronic game use (modified Loyd and Gressard Computer Anxiety Subscale) were assessed. Compared with home access to traditional electronic games, neither removal of all electronic games nor replacement with active-input games resulted in any significant change to child self-esteem, enjoyment of physical activity, or anxiety related to electronic games. Although active-input videogames have been shown to be enjoyable in the short term, their ability to impact on psychological outcomes is yet to be established.

Link Scheduling Algorithm with Interference Prediction for Multiple Mobile WBANs

PubMed Central

Le, Thien T. T.

2017-01-01

As wireless body area networks (WBANs) become a key element in electronic healthcare (e-healthcare) systems, the coexistence of multiple mobile WBANs is becoming an issue. The network performance is negatively affected by the unpredictable movement of the human body. In such an environment, inter-WBAN interference can be caused by the overlapping transmission range of nearby WBANs. We propose a link scheduling algorithm with interference prediction (LSIP) for multiple mobile WBANs, which allows multiple mobile WBANs to transmit at the same time without causing inter-WBAN interference. In the LSIP, a superframe includes the contention access phase using carrier sense multiple access with collision avoidance (CSMA/CA) and the scheduled phase using time division multiple access (TDMA) for non-interfering nodes and interfering nodes, respectively. For interference prediction, we define a parameter called interference duration as the duration during which disparate WBANs interfere with each other. The Bayesian model is used to estimate and classify the interference using a signal to interference plus noise ratio (SINR) and the number of neighboring WBANs. The simulation results show that the proposed LSIP algorithm improves the packet delivery ratio and throughput significantly with acceptable delay. PMID:28956827

Barriers to the Accessibility and Continuity of Health-Care Services in People with Multiple Sclerosis

PubMed Central

Bishop, Malachy; Pionke, J.J.; Strauser, David; Santens, Ryan L.

2017-01-01

Background: Individuals with multiple sclerosis (MS) face a range of barriers to accessing and using health-care services. The aim of this review was to identify specific barriers to accessing and using health-care services based on a continuum of the health-care delivery system. Methods: Literature searches were conducted in the PubMed, PsycINFO, CINAHL, and Web of Science databases. The following terms were searched as subject headings, key words, or abstracts: health care, access, barriers, physical disability, and multiple sclerosis. The literature search produced 361 potentially relevant citations. After screening titles, abstracts, and citations, eight citations were selected for full-text review. Results: Health-care barriers were divided into three continuous phases of receiving health care. In the before-visit phase, the most commonly identified barrier was transportation. In the during-visit phase, communication quality was the major concern. In the after-visit phase, discontinued referral was the major barrier encountered. Conclusions: There are multiple interrelated barriers to accessing and using health-care services along the health-care delivery continuum for people with MS and its associated physical disabilities, ranging from complex and long-recognized barriers that will likely require extended advocacy to create policy changes to issues that can and should be addressed through relatively minor changes in health-care delivery practices, improved care coordination, and increased provider awareness, education, and responsiveness to patients' needs. PMID:29270089

System and Method for Detecting Unauthorized Device Access by Comparing Multiple Independent Spatial-Time Data Sets from Other Devices

NASA Technical Reports Server (NTRS)

Westmeyer, Paul A. (Inventor); Wertenberg, Russell F. (Inventor); Krage, Frederick J. (Inventor); Riegel, Jack F. (Inventor)

2017-01-01

An authentication procedure utilizes multiple independent sources of data to determine whether usage of a device, such as a desktop computer, is authorized. When a comparison indicates an anomaly from the base-line usage data, the system, provides a notice that access of the first device is not authorized.

Persons with Multiple Disabilities Use Forehead and Smile Responses to Access or Choose among Technology-Aided Stimulation Events

ERIC Educational Resources Information Center

Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Alberti, Gloria; Bellini, Domencio; Oliva, Doretta; Boccasini, Adele; La Martire, Maria L.; Signorino, Mario

2013-01-01

A variety of technology-aided programs have been developed to help persons with congenital or acquired multiple disabilities access preferred stimuli or choose among stimulus options. The application of those programs may pose problems when the participants have very limited behavior repertoires and are unable to use conventional responses and…

Multiple Access Interference Reduction Using Received Response Code Sequence for DS-CDMA UWB System

NASA Astrophysics Data System (ADS)

Toh, Keat Beng; Tachikawa, Shin'ichi

This paper proposes a combination of novel Received Response (RR) sequence at the transmitter and a Matched Filter-RAKE (MF-RAKE) combining scheme receiver system for the Direct Sequence-Code Division Multiple Access Ultra Wideband (DS-CDMA UWB) multipath channel model. This paper also demonstrates the effectiveness of the RR sequence in Multiple Access Interference (MAI) reduction for the DS-CDMA UWB system. It suggests that by using conventional binary code sequence such as the M sequence or the Gold sequence, there is a possibility of generating extra MAI in the UWB system. Therefore, it is quite difficult to collect the energy efficiently although the RAKE reception method is applied at the receiver. The main purpose of the proposed system is to overcome the performance degradation for UWB transmission due to the occurrence of MAI during multiple accessing in the DS-CDMA UWB system. The proposed system improves the system performance by improving the RAKE reception performance using the RR sequence which can reduce the MAI effect significantly. Simulation results verify that significant improvement can be obtained by the proposed system in the UWB multipath channel models.

High security chaotic multiple access scheme for visible light communication systems with advanced encryption standard interleaving

NASA Astrophysics Data System (ADS)

Qiu, Junchao; Zhang, Lin; Li, Diyang; Liu, Xingcheng

2016-06-01

Chaotic sequences can be applied to realize multiple user access and improve the system security for a visible light communication (VLC) system. However, since the map patterns of chaotic sequences are usually well known, eavesdroppers can possibly derive the key parameters of chaotic sequences and subsequently retrieve the information. We design an advanced encryption standard (AES) interleaving aided multiple user access scheme to enhance the security of a chaotic code division multiple access-based visible light communication (C-CDMA-VLC) system. We propose to spread the information with chaotic sequences, and then the spread information is interleaved by an AES algorithm and transmitted over VLC channels. Since the computation complexity of performing inverse operations to deinterleave the information is high, the eavesdroppers in a high speed VLC system cannot retrieve the information in real time; thus, the system security will be enhanced. Moreover, we build a mathematical model for the AES-aided VLC system and derive the theoretical information leakage to analyze the system security. The simulations are performed over VLC channels, and the results demonstrate the effectiveness and high security of our presented AES interleaving aided chaotic CDMA-VLC system.

Tuning resistance states by thickness control in an electroforming-free nanometallic complementary resistance random access memory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xiang; Lu, Yang; Lee, Jongho

2016-01-04

Tuning low resistance state is crucial for resistance random access memory (RRAM) that aims to achieve optimal read margin and design flexibility. By back-to-back stacking two nanometallic bipolar RRAMs with different thickness into a complementary structure, we have found that its low resistance can be reliably tuned over several orders of magnitude. Such high tunability originates from the exponential thickness dependence of the high resistance state of nanometallic RRAM, in which electron wave localization in a random network gives rise to the unique scaling behavior. The complementary nanometallic RRAM provides electroforming-free, multi-resistance-state, sub-100 ns switching capability with advantageous characteristics formore » memory arrays.« less

Low power consumption resistance random access memory with Pt/InOx/TiN structure

NASA Astrophysics Data System (ADS)

Yang, Jyun-Bao; Chang, Ting-Chang; Huang, Jheng-Jie; Chen, Yu-Ting; Tseng, Hsueh-Chih; Chu, Ann-Kuo; Sze, Simon M.; Tsai, Ming-Jinn

2013-09-01

In this study, the resistance switching characteristics of a resistive random access memory device with Pt/InOx/TiN structure is investigated. Unstable bipolar switching behavior is observed during the initial switching cycle, which then stabilizes after several switching cycles. Analyses indicate that the current conduction mechanism in the resistance state is dominated by Ohmic conduction. The decrease in electrical conductance can be attributed to the reduction of the cross-sectional area of the conduction path. Furthermore, the device exhibits low operation voltage and power consumption.

Effect of Atomic Layer Depositions (ALD)-Deposited Titanium Oxide (TiO2) Thickness on the Performance of Zr40Cu35Al15Ni10 (ZCAN)/TiO2/Indium (In)-Based Resistive Random Access Memory (RRAM) Structures

DTIC Science & Technology

2015-08-01

metal structures, memristors, resistive random access memory, RRAM, titanium dioxide, Zr40Cu35Al15Ni10, ZCAN, resistive memory, tunnel junction 16...TiO2 thickness ........................6 1 1. Introduction Resistive-switching memory elements based on metal-insulator-metal (MIM) diodes ...have attracted great interest due to their potential as components for simple, inexpensive, and high-density non-volatile storage devices. MIM diodes

A random Q-switched fiber laser

PubMed Central

Tang, Yulong; Xu, Jianqiu

2015-01-01

Extensive studies have been performed on random lasers in which multiple-scattering feedback is used to generate coherent emission. Q-switching and mode-locking are well-known routes for achieving high peak power output in conventional lasers. However, in random lasers, the ubiquitous random cavities that are formed by multiple scattering inhibit energy storage, making Q-switching impossible. In this paper, widespread Rayleigh scattering arising from the intrinsic micro-scale refractive-index irregularities of fiber cores is used to form random cavities along the fiber. The Q-factor of the cavity is rapidly increased by stimulated Brillouin scattering just after the spontaneous emission is enhanced by random cavity resonances, resulting in random Q-switched pulses with high brightness and high peak power. This report is the first observation of high-brightness random Q-switched laser emission and is expected to stimulate new areas of scientific research and applications, including encryption, remote three-dimensional random imaging and the simulation of stellar lasing. PMID:25797520

A Review on Spectral Amplitude Coding Optical Code Division Multiple Access

NASA Astrophysics Data System (ADS)

Kaur, Navpreet; Goyal, Rakesh; Rani, Monika

2017-06-01

This manuscript deals with analysis of Spectral Amplitude Coding Optical Code Division Multiple Access (SACOCDMA) system. The major noise source in optical CDMA is co-channel interference from other users known as multiple access interference (MAI). The system performance in terms of bit error rate (BER) degrades as a result of increased MAI. It is perceived that number of users and type of codes used for optical system directly decide the performance of system. MAI can be restricted by efficient designing of optical codes and implementing them with unique architecture to accommodate more number of users. Hence, it is a necessity to design a technique like spectral direct detection (SDD) technique with modified double weight code, which can provide better cardinality and good correlation property.

A satellite mobile communication system based on Band-Limited Quasi-Synchronous Code Division Multiple Access (BLQS-CDMA)

NASA Technical Reports Server (NTRS)

Degaudenzi, R.; Elia, C.; Viola, R.

1990-01-01

Discussed here is a new approach to code division multiple access applied to a mobile system for voice (and data) services based on Band Limited Quasi Synchronous Code Division Multiple Access (BLQS-CDMA). The system requires users to be chip synchronized to reduce the contribution of self-interference and to make use of voice activation in order to increase the satellite power efficiency. In order to achieve spectral efficiency, Nyquist chip pulse shaping is used with no detection performance impairment. The synchronization problems are solved in the forward link by distributing a master code, whereas carrier forced activation and closed loop control techniques have been adopted in the return link. System performance sensitivity to nonlinear amplification and timing/frequency synchronization errors are analyzed.

Multiple Access Schemes for Lunar Missions

NASA Technical Reports Server (NTRS)

Deutsch, Leslie; Hamkins, Jon; Stocklin, Frank J.

2010-01-01

Two years ago, the NASA Coding, Modulation, and Link Protocol (CMLP) study was completed. The study, led by the authors of this paper, recommended codes, modulation schemes, and desired attributes of link protocols for all space communication links in NASA's future space architecture. Portions of the NASA CMLP team were reassembled to resolve one open issue: the use of multiple access (MA) communication from the lunar surface. The CMLP-MA team analyzed and simulated two candidate multiple access schemes that were identified in the original CMLP study: Code Division MA (CDMA) and Frequency Division MA (FDMA) based on a bandwidth-efficient Continuous Phase Modulation (CPM) with a superimposed Pseudo-Noise (PN) ranging signal (CPM/PN). This paper summarizes the results of the analysis and simulation of the CMLP-MA study and describes the final recommendations.

High data rate modem simulation for the space station multiple-access communications system

NASA Technical Reports Server (NTRS)

Horan, Stephen

1987-01-01

The communications system for the space station will require a space based multiple access component to provide communications between the space based program elements and the station. A study was undertaken to investigate two of the concerns of this multiple access system, namely, the issues related to the frequency spectrum utilization and the possibilities for higher order (than QPSK) modulation schemes for use in possible modulators and demodulators (modems). As a result of the investigation, many key questions about the frequency spectrum utilization were raised. At this point, frequency spectrum utilization is seen as an area requiring further work. Simulations were conducted using a computer aided communications system design package to provide a straw man modem structure to be used for both QPSK and 8-PSK channels.

Multiple Intimate Partner Violence Experiences: Knowledge, Access, Utilization and Barriers to Utilization of Resources by Women of the African Diaspora

PubMed Central

Sabri, Bushra; Huerta, Julia; Alexander, Kamila A.; St.Vil, Noelle M.; Campbell, Jacquelyn C.; Callwood, Gloria B.

2016-01-01

Objective This study examined knowledge, access, utilization, and barriers to use of resources among Black women exposed to multiple types of intimate partner violence in Baltimore, Maryland and the U.S. Virgin Islands (USVI). Methods We analyzed quantitative survey data collected by 163 women recruited from primary care, prenatal or family planning clinics in Baltimore and the USVI. In addition we analyzed qualitative data from in-depth interviews with 11 women. Quantitative data were analyzed using descriptive statistics and qualitative data were analyzed using thematic analysis. Results A substantial proportion of Black women with multiple types of violence experiences lacked knowledge of, did not have access to, and did not use resources. Barriers to resource use were identified at the individual, relationship, and community levels. Conclusion There is need for programs to develop awareness, promote access and utilization of resources, and eliminate barriers to resource use among abused Black women. PMID:26548679

Pediatric emergency medicine asynchronous e-learning: a multicenter randomized controlled Solomon four-group study.

PubMed

Chang, Todd P; Pham, Phung K; Sobolewski, Brad; Doughty, Cara B; Jamal, Nazreen; Kwan, Karen Y; Little, Kim; Brenkert, Timothy E; Mathison, David J

2014-08-01

Asynchronous e-learning allows for targeted teaching, particularly advantageous when bedside and didactic education is insufficient. An asynchronous e-learning curriculum has not been studied across multiple centers in the context of a clinical rotation. We hypothesize that an asynchronous e-learning curriculum during the pediatric emergency medicine (EM) rotation improves medical knowledge among residents and students across multiple participating centers. Trainees on pediatric EM rotations at four large pediatric centers from 2012 to 2013 were randomized in a Solomon four-group design. The experimental arms received an asynchronous e-learning curriculum consisting of nine Web-based, interactive, peer-reviewed Flash/HTML5 modules. Postrotation testing and in-training examination (ITE) scores quantified improvements in knowledge. A 2 × 2 analysis of covariance (ANCOVA) tested interaction and main effects, and Pearson's correlation tested associations between module usage, scores, and ITE scores. A total of 256 of 458 participants completed all study elements; 104 had access to asynchronous e-learning modules, and 152 were controls who used the current education standards. No pretest sensitization was found (p = 0.75). Use of asynchronous e-learning modules was associated with an improvement in posttest scores (p < 0.001), from a mean score of 18.45 (95% confidence interval [CI] = 17.92 to 18.98) to 21.30 (95% CI = 20.69 to 21.91), a large effect (partial η(2) = 0.19). Posttest scores correlated with ITE scores (r(2) = 0.14, p < 0.001) among pediatric residents. Asynchronous e-learning is an effective educational tool to improve knowledge in a clinical rotation. Web-based asynchronous e-learning is a promising modality to standardize education among multiple institutions with common curricula, particularly in clinical rotations where scheduling difficulties, seasonality, and variable experiences limit in-hospital learning. © 2014 by the Society for Academic Emergency Medicine.

Metro-access integrated network based on optical OFDMA with dynamic sub-carrier allocation and power distribution.

PubMed

Zhang, Chongfu; Zhang, Qiongli; Chen, Chen; Jiang, Ning; Liu, Deming; Qiu, Kun; Liu, Shuang; Wu, Baojian

2013-01-28

We propose and demonstrate a novel optical orthogonal frequency-division multiple access (OFDMA)-based metro-access integrated network with dynamic resource allocation. It consists of a single fiber OFDMA ring and many single fiber OFDMA trees, which transparently integrates metropolitan area networks with optical access networks. The single fiber OFDMA ring connects the core network and the central nodes (CNs), the CNs are on demand reconfigurable and use multiple orthogonal sub-carriers to realize parallel data transmission and dynamic resource allocation, meanwhile, they can also implement flexible power distribution. The remote nodes (RNs) distributed in the user side are connected by the single fiber OFDMA trees with the corresponding CN. The obtained results indicate that our proposed metro-access integrated network is feasible and the power distribution is agile.

Using Motion Planning to Determine the Existence of an Accessible Route in a CAD Environment

ERIC Educational Resources Information Center

Pan, Xiaoshan; Han, Charles S.; Law, Kincho H.

2010-01-01

We describe an algorithm based on motion-planning techniques to determine the existence of an accessible route through a facility for a wheeled mobility device. The algorithm is based on LaValle's work on rapidly exploring random trees and is enhanced to take into consideration the particularities of the accessible route domain. Specifically, the…

Assessing informed consent in an opioid relapse prevention study with adults under current or recent criminal justice supervision.

PubMed

Allen, Ashleigh A; Chen, Donna T; Bonnie, Richard J; Ko, Tomohiro M; Suratt, Colleen E; Lee, Joshua D; Friedmann, Peter D; Gordon, Michael; McDonald, Ryan; Murphy, Sean M; Boney, Tamara Y; Nunes, Edward V; O'Brien, Charles P

2017-10-01

Concerns persist that individuals with substance use disorders who are under community criminal justice supervision experience circumstances that might compromise their provision of valid, informed consent for research participation. These concerns include the possibilities that desire to obtain access to treatment might lead individuals to ignore important information about research participation, including information about risks, or that cognitive impairment associated with substance use might interfere with attending to important information. We report results from a consent quiz (CQ) administered in a multisite randomized clinical trial of long-acting naltrexone to prevent relapse to opioid use disorder among adults under community criminal justice supervision-a treatment option difficult to access by this population of individuals. Participants were required to answer all 11 items correctly before randomization. On average, participants answered 9.8 items correctly (89%) at baseline first attempt (n=306). At week 21 (n=212), participants scored 87% (9.5 items correct) without review. Performance was equivalent to, or better than, published results from other populations on a basic consent quiz instrument across multiple content domains. The consent quiz is an efficient method to screen for adequate knowledge of consent information as part of the informed consent process. Clinical researchers who are concerned about these issues should consider using a consent quiz with corrected feedback to enhance the informed consent process. Overall, while primarily useful as an educational tool, employing a CQ as part of the gateway to participation in research may be particularly important as the field continues to advance and tests novel experimental treatments with significant risks and uncertain potential for benefit. Copyright © 2017. Published by Elsevier Inc.

Feasibility of Using Soccer and Job Training to Prevent Drug Abuse and HIV

PubMed Central

Rotheram-Borus, Mary Jane; Tomlinson, Mark; Durkin, Andrew; Baird, Kelly; DeCelles, Jeff; Swendeman, Dallas

2016-01-01

Background Many young, South African men use alcohol and drugs and have multiple partners, but avoid health care settings – the primary site for delivery of HIV intervention activities. Objectives To identify the feasibility of engaging men in HIV testing and reducing substance use with soccer and vocational training programs. Methods In two Cape Town neighborhoods, all unemployed men aged 18–25 years were recruited and randomized by neighborhood to: 1) an immediate intervention condition with access to a soccer program, random rapid diagnostic tests (RDT) for alcohol and drug use, and an opportunity to enter a vocational training program (n=72); or 2) a delayed control condition (n=70). Young men were assessed at baseline and six months later by an independent team. Results Almost all young men in the two neighborhoods participated (98%); 85% attended at least one practice (M = 42.3, SD= 34.4); 71% typically attended practice. Access to job training was provided to the 35 young men with the most on-time arrivals at practice, drug-free RDT, and no red cards for violence. The percentage of young men agreeing to complete RDT at soccer increased significantly over time; RDTs with evidence of alcohol and drug use decreased over time. At the pre-post assessments, the frequency of substance use decreased; and employment and income increased in the immediate condition compared to the delayed condition. HIV testing rates, health care contacts, sexual behaviors, HIV knowledge, condom use and attitudes towards women were similar over time. Discussion Alternative engagement strategies are critical pathways to prevent HIV among young men. This feasibility study shows that soccer and job training offer such an alternative, and suggest that a more robust evaluation of this intervention strategy be pursued. PMID:26837624

Impact of explained v. unexplained front-of-package nutrition labels on parent and child food choices: a randomized trial.

PubMed

Graham, Dan J; Lucas-Thompson, Rachel G; Mueller, Megan P; Jaeb, Melanie; Harnack, Lisa

2017-04-01

The present study investigated whether parent/child pairs would select more healthful foods when: (i) products were labelled with front-of-package (FOP) nutrition labels relative to packages without labels; (ii) products were labelled with colour-coded Multiple Traffic Light (MTL) FOP labels relative to monochromatic Facts up Front (FuF) FOP labels; and (iii) FOP labels were explained via in-aisle signage v. unexplained. Participants were randomly assigned to one of five conditions: (i) FuF labels with in-aisle signs explaining the labels; (ii) FuF labels, no signage; (iii) MTL labels with in-aisle signage; (iv) MTL labels, no signage; (v) control group, no labels/signage. Saturated fat, sodium, sugar and energy (calorie) content were compared across conditions. The study took place in a laboratory grocery aisle. Parent/child pairs (n 153) completed the study. Results did not support the hypothesis that MTL labels would lead to more healthful choices than FuF labels. The presence of FOP labels did little to improve the healthfulness of selected foods, with few exceptions (participants with v. without access to FOP labels selected lower-calorie cereals, participants with access to both FOP labels and in-aisle explanatory signage selected products with less saturated fat v. participants without explanatory signage). Neither MTL nor FuF FOP labels led to food choices with significantly lower saturated fat, sodium or sugar. In-aisle signs explaining the FOP labels were somewhat helpful to consumers in making more healthful dietary decisions. New FOP labelling programmes could benefit from campaigns to increase consumer awareness and understanding of the labels.

Comparison of Preoperative Oral Ketorolac on Anesthetic Efficacy of Inferior Alveolar Nerve Block and Buccal and Lingual Infiltration with Articaine and Lidocaine in Patients with Irreversible Pulpitis: A Prospective, Randomized, Controlled, Double-blind Study.

PubMed

Yadav, Meetu; Grewal, Mandeep S; Grewal, Stutee; Deshwal, Parul

2015-11-01

Irreversible pulpitis (IP) commonly results in decreased anesthetic efficacy of the inferior alveolar nerve block (IANB) for mandibular molar. It has been shown that supplementary buccal and/or lingual infiltration as well as premedication with ketorolac result in improved efficacy of the IANB. One hundred fifty emergency patients who had their lower first or/and second molar diagnosed with IP participated in the study. All patients were randomly divided into 2 major IANB groups: 1 group received 4% articaine with 1:100,000 epinephrine, and the other group received 2% lidocaine with 1:80,000 epinephrine. Each group was further divided into 3 subgroups of 25 each: (1) buccal and lingual infiltration with articaine and lidocaine, respectively; (2) preoperative oral medication of ketorolac; and (3) preoperative oral medication of ketorolac followed by buccal and lingual infiltration with articaine and lidocaine, respectively. Endodontic access was initiated 15 minutes after solution deposition, and all patients were required to have profound lip numbness. Success of the anesthetic was defined as none or mild pain on endodontic access and initial instrumentation. Statistical analysis was performed using multiple-comparison analysis of variance (Kruskal-Wallis) and t tests. Articaine IANB with infiltrations plus oral ketorolac premedication significantly increased the success rate to 76%. The success rate after the administration of an articaine IANB with infiltration injections was 64%, whereas with lidocaine it was 32% (P < .05). Premedication with ketorolac significantly increases the anesthetic efficacy of articaine IANB plus infiltration in mandibular molars with IP. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Feasibility of Using Soccer and Job Training to Prevent Drug Abuse and HIV.

PubMed

Rotheram-Borus, Mary Jane; Tomlinson, Mark; Durkin, Andrew; Baird, Kelly; DeCelles, Jeff; Swendeman, Dallas

2016-09-01

Many young, South African men use alcohol and drugs and have multiple partners, but avoid health care settings-the primary site for delivery of HIV intervention activities. To identify the feasibility of engaging men in HIV testing and reducing substance use with soccer and vocational training programs. In two Cape Town neighborhoods, all unemployed men aged 18-25 years were recruited and randomized by neighborhood to: (1) an immediate intervention condition with access to a soccer program, random rapid diagnostic tests (RDT) for alcohol and drug use, and an opportunity to enter a vocational training program (n = 72); or (2) a delayed control condition (n = 70). Young men were assessed at baseline and 6 months later by an independent team. Almost all young men in the two neighborhoods participated (98 %); 85 % attended at least one practice (M = 42.3, SD = 34.4); 71 % typically attended practice. Access to job training was provided to the 35 young men with the most on-time arrivals at practice, drug-free RDT, and no red cards for violence. The percentage of young men agreeing to complete RDT at soccer increased significantly over time; RDTs with evidence of alcohol and drug use decreased over time. At the pre-post assessments, the frequency of substance use decreased; and employment and income increased in the immediate condition compared to the delayed condition. HIV testing rates, health care contacts, sexual behaviors, HIV knowledge, condom use and attitudes towards women were similar over time. Alternative engagement strategies are critical pathways to prevent HIV among young men. This feasibility study shows that soccer and job training offer such an alternative, and suggest that a more robust evaluation of this intervention strategy be pursued.

Multiple-trait structured antedependence model to study the relationship between litter size and birth weight in pigs and rabbits.

PubMed

David, Ingrid; Garreau, Hervé; Balmisse, Elodie; Billon, Yvon; Canario, Laurianne

2017-01-20

Some genetic studies need to take into account correlations between traits that are repeatedly measured over time. Multiple-trait random regression models are commonly used to analyze repeated traits but suffer from several major drawbacks. In the present study, we developed a multiple-trait extension of the structured antedependence model (SAD) to overcome this issue and validated its usefulness by modeling the association between litter size (LS) and average birth weight (ABW) over parities in pigs and rabbits. The single-trait SAD model assumes that a random effect at time [Formula: see text] can be explained by the previous values of the random effect (i.e. at previous times). The proposed multiple-trait extension of the SAD model consists in adding a cross-antedependence parameter to the single-trait SAD model. This model can be easily fitted using ASReml and the OWN Fortran program that we have developed. In comparison with the random regression model, we used our multiple-trait SAD model to analyze the LS and ABW of 4345 litters from 1817 Large White sows and 8706 litters from 2286 L-1777 does over a maximum of five successive parities. For both species, the multiple-trait SAD fitted the data better than the random regression model. The difference between AIC of the two models (AIC_random regression-AIC_SAD) were equal to 7 and 227 for pigs and rabbits, respectively. A similar pattern of heritability and correlation estimates was obtained for both species. Heritabilities were lower for LS (ranging from 0.09 to 0.29) than for ABW (ranging from 0.23 to 0.39). The general trend was a decrease of the genetic correlation for a given trait between more distant parities. Estimates of genetic correlations between LS and ABW were negative and ranged from -0.03 to -0.52 across parities. No correlation was observed between the permanent environmental effects, except between the permanent environmental effects of LS and ABW of the same parity, for which the estimate of the correlation was strongly negative (ranging from -0.57 to -0.67). We demonstrated that application of our multiple-trait SAD model is feasible for studying several traits with repeated measurements and showed that it provided a better fit to the data than the random regression model.

Adaptive Transmission and Channel Modeling for Frequency Hopping Communications

DTIC Science & Technology

2009-09-21

proposed adaptive transmission method has much greater system capacity than conventional non-adaptive MC direct- sequence ( DS )- CDMA system. • We...several mobile radio systems. First, a new improved allocation algorithm was proposed for multicarrier code-division multiple access (MC- CDMA ) system...Multicarrier code-division multiple access (MC- CDMA ) system with adaptive frequency hopping (AFH) has attracted attention of researchers due to its

Enhancing the Selection of Backoff Interval Using Fuzzy Logic over Wireless Ad Hoc Networks

PubMed Central

Ranganathan, Radha; Kannan, Kathiravan

2015-01-01

IEEE 802.11 is the de facto standard for medium access over wireless ad hoc network. The collision avoidance mechanism (i.e., random binary exponential backoff—BEB) of IEEE 802.11 DCF (distributed coordination function) is inefficient and unfair especially under heavy load. In the literature, many algorithms have been proposed to tune the contention window (CW) size. However, these algorithms make every node select its backoff interval between [0, CW] in a random and uniform manner. This randomness is incorporated to avoid collisions among the nodes. But this random backoff interval can change the optimal order and frequency of channel access among competing nodes which results in unfairness and increased delay. In this paper, we propose an algorithm that schedules the medium access in a fair and effective manner. This algorithm enhances IEEE 802.11 DCF with additional level of contention resolution that prioritizes the contending nodes according to its queue length and waiting time. Each node computes its unique backoff interval using fuzzy logic based on the input parameters collected from contending nodes through overhearing. We evaluate our algorithm against IEEE 802.11, GDCF (gentle distributed coordination function) protocols using ns-2.35 simulator and show that our algorithm achieves good performance. PMID:25879066

Traffic management mechanism for intranets with available-bit-rate access to the Internet

NASA Astrophysics Data System (ADS)

Hassan, Mahbub; Sirisena, Harsha R.; Atiquzzaman, Mohammed

1997-10-01

The design of a traffic management mechanism for intranets connected to the Internet via an available bit rate access- link is presented. Selection of control parameters for this mechanism for optimum performance is shown through analysis. An estimate for packet loss probability at the access- gateway is derived for random fluctuation of available bit rate of the access-link. Some implementation strategies of this mechanism in the standard intranet protocol stack are also suggested.

Multiple-Input Multiple-Output (MIMO) Linear Systems Extreme Inputs/Outputs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smallwood, David O.

2007-01-01

A linear structure is excited at multiple points with a stationary normal random process. The response of the structure is measured at multiple outputs. If the autospectral densities of the inputs are specified, the phase relationships between the inputs are derived that will minimize or maximize the trace of the autospectral density matrix of the outputs. If the autospectral densities of the outputs are specified, the phase relationships between the outputs that will minimize or maximize the trace of the input autospectral density matrix are derived. It is shown that other phase relationships and ordinary coherence less than one willmore » result in a trace intermediate between these extremes. Least favorable response and some classes of critical response are special cases of the development. It is shown that the derivation for stationary random waveforms can also be applied to nonstationary random, transients, and deterministic waveforms.« less

Educational Outcomes of Small-Group Discussion Versus Traditional Lecture Format in Dental Students' Learning and Skills Acquisition.

PubMed

Arias, Ana; Scott, Raymond; Peters, Ove A; McClain, Elizabeth; Gluskin, Alan H

2016-04-01

The aim of this prospective quantitative study was to compare the effect of different instructional formats on dental students' skills and knowledge acquisition for access cavity preparation. All first-year dental students were invited to participate in this study conducted during the four consecutive two-week endodontic rotation courses at the University of the Pacific Arthur A. Dugoni School of Dentistry in spring semester 2015. Four alphabetically distributed intact groups of students were randomly allocated to two groups (n=70 each) that participated in either small-group discussion or a traditional lecture on access preparation. The first outcome measure was skill acquisition, measured by the quality of access cavities prepared in extracted teeth at the conclusion of the session. Two blinded raters scored direct observations on a continuous scale. Knowledge, the second outcome measure, was scored with a multiple-choice and open-ended question test at the end of each two-week session. Data were obtained for 134 of the 140 students, for a 96% response rate. The results showed that students in the small-group discussion groups scored significantly higher than those in the lecture groups when skill performance was tested (p=8.9 × 10(-7)). However, no significant differences were found in the acquisition of knowledge between the two groups on the written test. Active student participation was significantly related to improved manual skill acquisition, but the format of the session does not seem to have had a direct influence on acquired knowledge.

Factors predicting teachers' attitudes towards the use of ICT in teaching and learning

NASA Astrophysics Data System (ADS)

Ayub, Ahmad Fauzi Mohd; Bakar, Kamariah Abu; Ismail, Rohayati

2015-10-01

Technology has revolutionized in the field of Education. The importance of technology in schools cannot be ignored. While it is important that mathematics teachers should have positive attitudes towards adopting ICT in their teaching, various problems can arise when integrating ICT into classroom lessons. This study explored the factors that influence the attitudes of mathematic teachers in the integration of ICT in the teaching and learning process. A total of 187 mathematics teachers from the state of Selangor in Malaysia were randomly selected from a stratified cluster sample. The research examined five factors that were postulated to impact teachers' attitudes towards the integration of ICT in their lessons, viz. teachers' technology competence, school culture, access to ICT, school support, and years of classroom teaching experience. The findings showed that the teachers' attitudes towards using ICT in teaching and learning were positively correlated with the teachers' technology competence [r = .41; p < .01], ICT school culture [r = .261; p < .01], school support [r = .366; p < .01] and access to ICT resources [r = .220; p < .01]. However, a negative relationship existed between years of teaching and attitudes towards using ICT in teaching and learning [r = -0.192; p < .01]. A multiple regression analysis showed that 29.1% of the variation in teachers' attitudes towards using ICT in the classroom was explained by the variation in teachers' technology competence, school support and school culture, with the effects of teaching experience and ICT resource access being negligible.

Multiple deprivation, vision loss, and ophthalmic disease in adults: global perspectives.

PubMed

Lane, Mark; Lane, Victoria; Abbott, Joseph; Braithwaite, Tasanee; Shah, Peter; Denniston, Alastair K

The association between socioeconomic position and morbidity and mortality has long been recognized. We evaluate the evidence for an association between multiple aspects of deprivation and ocular health in a global context. This is a systematic review of studies that evaluated deprivation in the adult population in the context of the major acquired causes of visual loss such as cataract, diabetic eye disease, glaucoma, age-related macular degeneration, and ocular trauma. The search strategy identified relevant studies reported between 1946 and August 2016, with randomized control trials, case-control, cohort, and cross-sectional study designs being selected for inclusion. The studies identified in this review from across the world demonstrate the extent to which the common themes such as low educational attainment and low income may be associated with increased incidence of various sight-threatening conditions and may adversely affect access to specialist assessment and delivery of treatment. Health inequality may always persist, but an increased recognition of the importance of the various impacts of deprivation may empower policy makers to target limited resources to the most vulnerable groups in order to deliver the greatest benefit. Copyright © 2017 Elsevier Inc. All rights reserved.

Leveraging Random Number Generation for Mastery of Learning in Teaching Quantitative Research Courses via an E-Learning Method

ERIC Educational Resources Information Center

Boonsathorn, Wasita; Charoen, Danuvasin; Dryver, Arthur L.

2014-01-01

E-Learning brings access to a powerful but often overlooked teaching tool: random number generation. Using random number generation, a practically infinite number of quantitative problem-solution sets can be created. In addition, within the e-learning context, in the spirit of the mastery of learning, it is possible to assign online quantitative…

Motivational Interviewing May Improve Exercise Experience for People with Multiple Sclerosis: A Small Randomized Trial

ERIC Educational Resources Information Center

Smith, Douglas C.; Lanesskog, Deirdre; Cleeland, Leah; Motl, Robert; Weikert, Madeline; Dlugonski, Deirdre

2012-01-01

People with multiple sclerosis (MS) are likely to benefit from regular exercise, but physical inactivity is more common among people with MS than among the general population. This small randomized study evaluated whether motivational interviewing (MI) affects adherence to and personal experience in an exercise program. Inactive people with MS…

Multiple Imputation of Item Scores in Test and Questionnaire Data, and Influence on Psychometric Results

ERIC Educational Resources Information Center

van Ginkel, Joost R.; van der Ark, L. Andries; Sijtsma, Klaas

2007-01-01

The performance of five simple multiple imputation methods for dealing with missing data were compared. In addition, random imputation and multivariate normal imputation were used as lower and upper benchmark, respectively. Test data were simulated and item scores were deleted such that they were either missing completely at random, missing at…

Impact of economic sanctions on access to noncommunicable diseases medicines in the Islamic Republic of Iran.

PubMed

Kheirandish, Mehrnaz; Varahrami, Vida; Kebriaeezade, Abbas; Cheraghali, Abdol Majid

2018-04-05

It has been argued that economic sanctions and the economic crisis have adversely affected access to drugs. To assess the impact of economic sanctions on the Iranian banking system in 2011 and Central Bank in 2012 on access to and use of drugs for noncommunicable diseases (NCDs). An interrupted time series study assessed the effects of sanctions on drugs for diabetes (5 drug groups), asthma (5 drug groups), cancer (14 drugs) and multiple sclerosis (2 drugs). We extracted data from national reference databases on the list of drugs on the Iranian pharmaceutical market before 2011 for each selected NCD and their monthly sales. For cancer drugs, we used stratified random sampling by volume and value of sales, and source of supply (domestic or imported). Data were analysed monthly from 2008 to 2013. Market availability of 13 of 26 drugs was significantly reduced. Ten other drugs showed nonsignificant reductions in their market availability. Interferon α2b usage reduced from 0.014 defined daily doses per 1000 inhabitants per day (DID) in 2010 to 0.008 in 2013; and cytarabine from 1.40 mg per 1000 population per day in 2010 to 0.96 in 2013. Selective β2-adrenoreceptor agonists usage reduced from 8.4 to 6.8 DID in the same time period. There is strong evidence that sanctions have had a negative effect on access to drugs, particularly those that depended on the import of their raw material or finished products. Copyright © World Health Organization (WHO) 2018. Some rights reserved. This work is available under the CC BY-NC-SA 3.0 IGO license (https://creativecommons.org/licenses/by-nc-sa/3.0/igo).

A survey of accessibility and utilisation of chiropractic services for wheelchair-users in the United Kingdom: What are the issues?

PubMed

McKay, Naomi D; Langworthy, Jennifer

2011-09-13

People with physical disabilities experience barriers to healthcare across all services despite a legal and moral obligation to the contrary. Complementary medicine is considered as supplementary to conventional care and integration of these approaches is essential to achieve optimal care. This paper explores the utilisation of chiropractic services and practitioner experiences of treating wheelchair-users which appears under-reported. A 20 item questionnaire was posted to 250 randomly selected chiropractors registered with the General Chiropractic Council. Follow-up questionnaires were sent 7 days after the initial return date. Quantitative data were subjected to frequency analysis. The response rate was 64% (n = 161). The majority (66%) of chiropractors had been in practice less than 10 years and were practice owners (50%). Fifty-two percent of chiropractors sampled had treated a patient in a wheelchair in the previous 5 years. The majority (87%) had treated between 1 and 5 such patients. Patients with multiple sclerosis, stroke and cerebral palsy most commonly presented for treatment. The majority of patients' presenting complaint was musculoskeletal in origin, primarily for pain control. Only 13% of respondents worked in a fully accessible clinic. Impracticality of alterations was the most common reason for inaccessibility. Wheelchair-users seem to be an underserved patient group in relation to chiropractic services. Chiropractic management is primarily utilised for pain control in patients with physical disabilities in which mobility may be improved or maintained. Co-management of wheelchair-users with GPs appears to be desirable in order to achieve optimal patient care however more research is required regarding the efficacy of chiropractic treatment for a range of disabling conditions. Physical access was identified as a key barrier to accessing care.

Three-dimensional mapping of microcircuit correlation structure

PubMed Central

Cotton, R. James; Froudarakis, Emmanouil; Storer, Patrick; Saggau, Peter; Tolias, Andreas S.

2013-01-01

Great progress has been made toward understanding the properties of single neurons, yet the principles underlying interactions between neurons remain poorly understood. Given that connectivity in the neocortex is locally dense through both horizontal and vertical connections, it is of particular importance to characterize the activity structure of local populations of neurons arranged in three dimensions. However, techniques for simultaneously measuring microcircuit activity are lacking. We developed an in vivo 3D high-speed, random-access two-photon microscope that is capable of simultaneous 3D motion tracking. This allows imaging from hundreds of neurons at several hundred Hz, while monitoring tissue movement. Given that motion will induce common artifacts across the population, accurate motion tracking is absolutely necessary for studying population activity with random-access based imaging methods. We demonstrate the potential of this imaging technique by measuring the correlation structure of large populations of nearby neurons in the mouse visual cortex, and find that the microcircuit correlation structure is stimulus-dependent. Three-dimensional random access multiphoton imaging with concurrent motion tracking provides a novel, powerful method to characterize the microcircuit activity in vivo. PMID:24133414

On Several Fundamental Problems of Optimization, Estimation, and Scheduling in Wireless Communications

NASA Astrophysics Data System (ADS)

Gao, Qian

For both the conventional radio frequency and the comparably recent optical wireless communication systems, extensive effort from the academia had been made in improving the network spectrum efficiency and/or reducing the error rate. To achieve these goals, many fundamental challenges such as power efficient constellation design, nonlinear distortion mitigation, channel training design, network scheduling and etc. need to be properly addressed. In this dissertation, novel schemes are proposed accordingly to deal with specific problems falling in category of these challenges. Rigorous proofs and analyses are provided for each of our work to make a fair comparison with the corresponding peer works to clearly demonstrate the advantages. The first part of this dissertation considers a multi-carrier optical wireless system employing intensity modulation (IM) and direct detection (DD). A block-wise constellation design is presented, which treats the DC-bias that conventionally used solely for biasing purpose as an information basis. Our scheme, we term it MSM-JDCM, takes advantage of the compactness of sphere packing in a higher dimensional space, and in turn power efficient constellations are obtained by solving an advanced convex optimization problem. Besides the significant power gains, the MSM-JDCM has many other merits such as being capable of mitigating nonlinear distortion by including a peak-to-power ratio (PAPR) constraint, minimizing inter-symbol-interference (ISI) caused by frequency-selective fading with a novel precoder designed and embedded, and further reducing the bit-error-rate (BER) by combining with an optimized labeling scheme. The second part addresses several optimization problems in a multi-color visible light communication system, including power efficient constellation design, joint pre-equalizer and constellation design, and modeling of different structured channels with cross-talks. Our novel constellation design scheme, termed CSK-Advanced, is compared with the conventional decoupled system with the same spectrum efficiency to demonstrate the power efficiency. Crucial lighting requirements are included as optimization constraints. To control non-linear distortion, the optical peak-to-average-power ratio (PAPR) of LEDs can be individually constrained. With a SVD-based pre-equalizer designed and employed, our scheme can achieve lower BER than counterparts applying zero-forcing (ZF) or linear minimum-mean-squared-error (LMMSE) based post-equalizers. Besides, a binary switching algorithm (BSA) is applied to improve BER performance. The third part looks into a problem of two-phase channel estimation in a relayed wireless network. The channel estimates in every phase are obtained by the linear minimum mean squared error (LMMSE) method. Inaccurate estimate of the relay to destination (RtD) channel in phase 1 could affect estimate of the source to relay (StR) channel in phase 2, which is made erroneous. We first derive a close-form expression for the averaged Bayesian mean-square estimation error (ABMSE) for both phase estimates in terms of the length of source and relay training slots, based on which an iterative searching algorithm is then proposed that optimally allocates training slots to the two phases such that estimation errors are balanced. Analysis shows how the ABMSE of the StD channel estimation varies with the lengths of relay training and source training slots, the relay amplification gain, and the channel prior information respectively. The last part deals with a transmission scheduling problem in a uplink multiple-input-multiple-output (MIMO) wireless network. Code division multiple access (CDMA) is assumed as a multiple access scheme and pseudo-random codes are employed for different users. We consider a heavy traffic scenario, in which each user always has packets to transmit in the scheduled time slots. If the relay is scheduled for transmission together with users, then it operates in a full-duplex mode, where the packets previously collected from users are transmitted to the destination while new packets are being collected from users. A novel expression of throughput is first derived and then used to develop a scheduling algorithm to maximize the throughput. Our full-duplex scheduling is compared with a half-duplex scheduling, random access, and time division multiple access (TDMA), and simulation results illustrate its superiority. Throughput gains due to employment of both MIMO and CDMA are observed.

Cost effectiveness of different central venous approaches for port placement and use in adult oncology patients: evidence from a randomized three-arm trial.

PubMed

Biffi, Roberto; Pozzi, Simonetta; Bonomo, Guido; Della Vigna, Paolo; Monfardini, Lorenzo; Radice, Davide; Rotmensz, Nicole; Zampino, Maria Giulia; Fazio, Nicola; Orsi, Franco

2014-11-01

No randomized trials have so far investigated the cost effectiveness of different methods for implantation and use of central venous ports in oncology patients. Overall, 403 patients eligible for receiving intravenous chemotherapy for solid tumours were randomly assigned to implantation of a single type of port, either through a percutaneous landmark access to the internal jugular vein, an ultrasound (US)-guided access to the subclavian vein, or a surgical cut-down access through the cephalic vein at the deltoid-pectoralis groove. Insertion and maintenance costs were estimated by obtaining the charges for an average implant and use, while the costs of the management of complications were analytically assessed. The total cost was defined as the purchase cost plus the insertion cost plus the maintenance cost plus the cost of treatment of the complications, if any. A total of 401 patients were evaluable-132 with the internal jugular vein, 136 with the subclavian vein and 133 with the cephalic vein access. No differences were found for the rate of early complications. The US-guided subclavian insertion site had significantly lower failures. Infections occurred in 1, 3, and 3 patients (internal jugular, subclavian, and cephalic access, respectively; p = 0.464), whereas venous thrombosis was observed in 15, 8, and 11 patients, respectively (p = 0.272). Mean cost for purchase, implantation, diagnosis and treatment of complications in each patient was 2,167.85 for subclavian US-guided, 2,335.87 for cephalic, and 2,384.10 for internal jugular access, respectively (p = 0.0001). US real-time guidance to the subclavian vein resulted in the most cost-effective method of central venous port placement and use.

Distributed magnetic field positioning system using code division multiple access

NASA Technical Reports Server (NTRS)

Prigge, Eric A. (Inventor)

2003-01-01

An apparatus and methods for a magnetic field positioning system use a fundamentally different, and advantageous, signal structure and multiple access method, known as Code Division Multiple Access (CDMA). This signal architecture, when combined with processing methods, leads to advantages over the existing technologies, especially when applied to a system with a large number of magnetic field generators (beacons). Beacons at known positions generate coded magnetic fields, and a magnetic sensor measures a sum field and decomposes it into component fields to determine the sensor position and orientation. The apparatus and methods can have a large `building-sized` coverage area. The system allows for numerous beacons to be distributed throughout an area at a number of different locations. A method to estimate position and attitude, with no prior knowledge, uses dipole fields produced by these beacons in different locations.

Impulsive synchronization of Markovian jumping randomly coupled neural networks with partly unknown transition probabilities via multiple integral approach.

PubMed

Chandrasekar, A; Rakkiyappan, R; Cao, Jinde

2015-10-01

This paper studies the impulsive synchronization of Markovian jumping randomly coupled neural networks with partly unknown transition probabilities via multiple integral approach. The array of neural networks are coupled in a random fashion which is governed by Bernoulli random variable. The aim of this paper is to obtain the synchronization criteria, which is suitable for both exactly known and partly unknown transition probabilities such that the coupled neural network is synchronized with mixed time-delay. The considered impulsive effects can be synchronized at partly unknown transition probabilities. Besides, a multiple integral approach is also proposed to strengthen the Markovian jumping randomly coupled neural networks with partly unknown transition probabilities. By making use of Kronecker product and some useful integral inequalities, a novel Lyapunov-Krasovskii functional was designed for handling the coupled neural network with mixed delay and then impulsive synchronization criteria are solvable in a set of linear matrix inequalities. Finally, numerical examples are presented to illustrate the effectiveness and advantages of the theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.

Feedback power control strategies in wireless sensor networks with joint channel decoding.

PubMed

Abrardo, Andrea; Ferrari, Gianluigi; Martalò, Marco; Perna, Fabio

2009-01-01

In this paper, we derive feedback power control strategies for block-faded multiple access schemes with correlated sources and joint channel decoding (JCD). In particular, upon the derivation of the feasible signal-to-noise ratio (SNR) region for the considered multiple access schemes, i.e., the multidimensional SNR region where error-free communications are, in principle, possible, two feedback power control strategies are proposed: (i) a classical feedback power control strategy, which aims at equalizing all link SNRs at the access point (AP), and (ii) an innovative optimized feedback power control strategy, which tries to make the network operational point fall in the feasible SNR region at the lowest overall transmit energy consumption. These strategies will be referred to as "balanced SNR" and "unbalanced SNR," respectively. While they require, in principle, an unlimited power control range at the sources, we also propose practical versions with a limited power control range. We preliminary consider a scenario with orthogonal links and ideal feedback. Then, we analyze the robustness of the proposed power control strategies to possible non-idealities, in terms of residual multiple access interference and noisy feedback channels. Finally, we successfully apply the proposed feedback power control strategies to a limiting case of the class of considered multiple access schemes, namely a central estimating officer (CEO) scenario, where the sensors observe noisy versions of a common binary information sequence and the AP's goal is to estimate this sequence by properly fusing the soft-output information output by the JCD algorithm.

Lexical access changes in patients with multiple sclerosis: a two-year follow-up study.

PubMed

Sepulcre, Jorge; Peraita, Herminia; Goni, Joaquin; Arrondo, Gonzalo; Martincorena, Inigo; Duque, Beatriz; Velez de Mendizabal, Nieves; Masdeu, Joseph C; Villoslada, Pablo

2011-02-01

The aim of the study was to analyze lexical access strategies in patients with multiple sclerosis (MS) and their changes over time. We studied lexical access strategies during semantic and phonemic verbal fluency tests and also confrontation naming in a 2-year prospective cohort of 45 MS patients and 20 healthy controls. At baseline, switching lexical access strategy (both in semantic and in phonemic verbal fluency tests) and confrontation naming were significantly impaired in MS patients compared with controls. After 2 years follow-up, switching score decreased, and cluster size increased over time in semantic verbal fluency tasks, suggesting a failure in the retrieval of lexical information rather than an impairment of the lexical pool. In conclusion, these findings underline the significant presence of lexical access problems in patients with MS and could point out their key role in the alterations of high-level communications abilities in MS.

Mobile access to virtual randomization for investigator-initiated trials.

PubMed

Deserno, Thomas M; Keszei, András P

2017-08-01

Background/aims Randomization is indispensable in clinical trials in order to provide unbiased treatment allocation and a valid statistical inference. Improper handling of allocation lists can be avoided using central systems, for example, human-based services. However, central systems are unaffordable for investigator-initiated trials and might be inaccessible from some places, where study subjects need allocations. We propose mobile access to virtual randomization, where the randomization lists are non-existent and the appropriate allocation is computed on demand. Methods The core of the system architecture is an electronic data capture system or a clinical trial management system, which is extended by an R interface connecting the R server using the Java R Interface. Mobile devices communicate via the representational state transfer web services. Furthermore, a simple web-based setup allows configuring the appropriate statistics by non-statisticians. Our comprehensive R script supports simple randomization, restricted randomization using a random allocation rule, block randomization, and stratified randomization for un-blinded, single-blinded, and double-blinded trials. For each trial, the electronic data capture system or the clinical trial management system stores the randomization parameters and the subject assignments. Results Apps are provided for iOS and Android and subjects are randomized using smartphones. After logging onto the system, the user selects the trial and the subject, and the allocation number and treatment arm are displayed instantaneously and stored in the core system. So far, 156 subjects have been allocated from mobile devices serving five investigator-initiated trials. Conclusion Transforming pre-printed allocation lists into virtual ones ensures the correct conduct of trials and guarantees a strictly sequential processing in all trial sites. Covering 88% of all randomization models that are used in recent trials, virtual randomization becomes available for investigator-initiated trials and potentially for large multi-center trials.

A Study of the Seastar Underwater Acoustic Local Area Network Concept

DTIC Science & Technology

2007-12-01

sense multiple access (CSMA) and multiple access with collision avoidance ( MACA ) are reviewed in [19, 22, 23, 34]. Peripheral nodes using ALOHA and...transmissions until the channel is clear. However, the long propagation time limits the effectiveness of CSMA for acoustic communications. MACA [22] uses... MACA protocol, if no ACK message is received after the transmission is completed, the full packet will be retransmitted until reception is

Space-Time Processing for Tactical Mobile Ad Hoc Networks

DTIC Science & Technology

2010-05-01

Spatial Diversity and Imperfect Channel Estimation on Wideband MC- DS - CDMA and MC- CDMA " IEEE Transactions on Communications, Vol. 57, No. 10, pp. 2988...include direct sequence code division multiple access ( DS - CDMA ), Frequency Hopped (FH) CDMA and Orthogonal Frequency Division Multiple Access (OFDMA...capability, LPD/LPI, and operability in non-continuous spectrum. In addition, FH- CDMA is robust to the near-far problem, while DS - CDMA requires

ABSENTEE COMPUTATIONS IN A MULTIPLE-ACCESS COMPUTER SYSTEM.

DTIC Science & Technology

require user interaction, and the user may therefore want to run these computations ’ absentee ’ (or, user not present). A mechanism is presented which...provides for the handling of absentee computations in a multiple-access computer system. The design is intended to be implementation-independent...Some novel features of the system’s design are: a user can switch computations from interactive to absentee (and vice versa), the system can

Parallel Object Activation and Attentional Gating of Information: Evidence from Eye Movements in the Multiple Object Naming Paradigm

ERIC Educational Resources Information Center

Schotter, Elizabeth R.; Ferreira, Victor S.; Rayner, Keith

2013-01-01

Do we access information from any object we can see, or do we access information only from objects that we intend to name? In 3 experiments using a modified multiple object naming paradigm, subjects were required to name several objects in succession when previews appeared briefly and simultaneously in the same location as the target as well as at…

Single-incision Laparoscopic Surgery (SILS) in general surgery: a review of current practice.

PubMed

Froghi, Farid; Sodergren, Mikael Hans; Darzi, Ara; Paraskeva, Paraskevas

2010-08-01

Single-incision laparoscopic surgery (SILS) aims to eliminate multiple port incisions. Although general operative principles of SILS are similar to conventional laparoscopic surgery, operative techniques are not standardized. This review aims to evaluate the current use of SILS published in the literature by examining the types of operations performed, techniques employed, and relevant complications and morbidity. This review considered a total of 94 studies reporting 1889 patients evaluating 17 different general surgical operations. There were 8 different access techniques reported using conventional laparoscopic instruments and specifically designed SILS ports. There is extensive heterogeneity associated with operating methods and in particular ways of overcoming problems with retraction and instrumentation. Published complications, morbidity, and hospital length of stay are comparable to conventional laparoscopy. Although SILS provides excellent cosmetic results and morbidity seems similar to conventional laparoscopy, larger randomized controlled trials are needed to assess the safety and efficacy of this novel technique.

Cooperative multi-user detection and ranging based on pseudo-random codes

NASA Astrophysics Data System (ADS)

Morhart, C.; Biebl, E. M.

2009-05-01

We present an improved approach for a Round Trip Time of Flight distance measurement system. The system is intended for the usage in a cooperative localisation system for automotive applications. Therefore, it is designed to address a large number of communication partners per measurement cycle. By using coded signals in a time divison multiple access order, we can detect a large number of pedestrian sensors with just one car sensor. We achieve this by using very short transmit bursts in combination with a real time correlation algorithm. Futhermore, the correlation approach offers real time data, concerning the time of arrival, that can serve as a trigger impulse for other comunication systems. The distance accuracy of the correlation result was further increased by adding a fourier interpolation filter. The system performance was checked with a prototype at 2.4 GHz. We reached a distance measurement accuracy of 12 cm at a range up to 450 m.

Reduced representation approaches to interrogate genome diversity in large repetitive plant genomes.

PubMed

Hirsch, Cory D; Evans, Joseph; Buell, C Robin; Hirsch, Candice N

2014-07-01

Technology and software improvements in the last decade now provide methodologies to access the genome sequence of not only a single accession, but also multiple accessions of plant species. This provides a means to interrogate species diversity at the genome level. Ample diversity among accessions in a collection of species can be found, including single-nucleotide polymorphisms, insertions and deletions, copy number variation and presence/absence variation. For species with small, non-repetitive rich genomes, re-sequencing of query accessions is robust, highly informative, and economically feasible. However, for species with moderate to large sized repetitive-rich genomes, technical and economic barriers prevent en masse genome re-sequencing of accessions. Multiple approaches to access a focused subset of loci in species with larger genomes have been developed, including reduced representation sequencing, exome capture and transcriptome sequencing. Collectively, these approaches have enabled interrogation of diversity on a genome scale for large plant genomes, including crop species important to worldwide food security. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Multiple-access phased array antenna simulator for a digital beam-forming system investigation

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Yu, John; Walton, Joanne C.; Perl, Thomas D.; Andro, Monty; Alexovich, Robert E.

1992-01-01

Future versions of data relay satellite systems are currently being planned by NASA. Being given consideration for implementation are on-board digital beamforming techniques which will allow multiple users to simultaneously access a single S-band phased array antenna system. To investigate the potential performance of such a system, a laboratory simulator has been developed at NASA's Lewis Research Center. This paper describes the system simulator, and in particular, the requirements, design and performance of a key subsystem, the phased array antenna simulator, which provides realistic inputs to the digital processor including multiple signals, noise, and nonlinearities.

Multiple-access phased array antenna simulator for a digital beam forming system investigation

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Yu, John; Walton, Joanne C.; Perl, Thomas D.; Andro, Monty; Alexovich, Robert E.

1992-01-01

Future versions of data relay satellite systems are currently being planned by NASA. Being given consideration for implementation are on-board digital beamforming techniques which will allow multiple users to simultaneously access a single S-band phased array antenna system. To investigate the potential performance of such a system, a laboratory simulator has been developed at NASA's Lewis Research Center. This paper describes the system simulator, and in particular, the requirements, design, and performance of a key subsystem, the phased array antenna simulator, which provides realistic inputs to the digital processor including multiple signals, noise, and nonlinearities.

Random walks with random velocities.

PubMed

Zaburdaev, Vasily; Schmiedeberg, Michael; Stark, Holger

2008-07-01

We consider a random walk model that takes into account the velocity distribution of random walkers. Random motion with alternating velocities is inherent to various physical and biological systems. Moreover, the velocity distribution is often the first characteristic that is experimentally accessible. Here, we derive transport equations describing the dispersal process in the model and solve them analytically. The asymptotic properties of solutions are presented in the form of a phase diagram that shows all possible scaling regimes, including superdiffusive, ballistic, and superballistic motion. The theoretical results of this work are in excellent agreement with accompanying numerical simulations.

Solving large mixed linear models using preconditioned conjugate gradient iteration.

PubMed

Strandén, I; Lidauer, M

1999-12-01

Continuous evaluation of dairy cattle with a random regression test-day model requires a fast solving method and algorithm. A new computing technique feasible in Jacobi and conjugate gradient based iterative methods using iteration on data is presented. In the new computing technique, the calculations in multiplication of a vector by a matrix were recorded to three steps instead of the commonly used two steps. The three-step method was implemented in a general mixed linear model program that used preconditioned conjugate gradient iteration. Performance of this program in comparison to other general solving programs was assessed via estimation of breeding values using univariate, multivariate, and random regression test-day models. Central processing unit time per iteration with the new three-step technique was, at best, one-third that needed with the old technique. Performance was best with the test-day model, which was the largest and most complex model used. The new program did well in comparison to other general software. Programs keeping the mixed model equations in random access memory required at least 20 and 435% more time to solve the univariate and multivariate animal models, respectively. Computations of the second best iteration on data took approximately three and five times longer for the animal and test-day models, respectively, than did the new program. Good performance was due to fast computing time per iteration and quick convergence to the final solutions. Use of preconditioned conjugate gradient based methods in solving large breeding value problems is supported by our findings.

Privacy-preserving outlier detection through random nonlinear data distortion.

PubMed

Bhaduri, Kanishka; Stefanski, Mark D; Srivastava, Ashok N

2011-02-01

Consider a scenario in which the data owner has some private or sensitive data and wants a data miner to access them for studying important patterns without revealing the sensitive information. Privacy-preserving data mining aims to solve this problem by randomly transforming the data prior to their release to the data miners. Previous works only considered the case of linear data perturbations--additive, multiplicative, or a combination of both--for studying the usefulness of the perturbed output. In this paper, we discuss nonlinear data distortion using potentially nonlinear random data transformation and show how it can be useful for privacy-preserving anomaly detection from sensitive data sets. We develop bounds on the expected accuracy of the nonlinear distortion and also quantify privacy by using standard definitions. The highlight of this approach is to allow a user to control the amount of privacy by varying the degree of nonlinearity. We show how our general transformation can be used for anomaly detection in practice for two specific problem instances: a linear model and a popular nonlinear model using the sigmoid function. We also analyze the proposed nonlinear transformation in full generality and then show that, for specific cases, it is distance preserving. A main contribution of this paper is the discussion between the invertibility of a transformation and privacy preservation and the application of these techniques to outlier detection. The experiments conducted on real-life data sets demonstrate the effectiveness of the approach.

Paging memory from random access memory to backing storage in a parallel computer

DOEpatents

Archer, Charles J; Blocksome, Michael A; Inglett, Todd A; Ratterman, Joseph D; Smith, Brian E

2013-05-21

Paging memory from random access memory (`RAM`) to backing storage in a parallel computer that includes a plurality of compute nodes, including: executing a data processing application on a virtual machine operating system in a virtual machine on a first compute node; providing, by a second compute node, backing storage for the contents of RAM on the first compute node; and swapping, by the virtual machine operating system in the virtual machine on the first compute node, a page of memory from RAM on the first compute node to the backing storage on the second compute node.

A Study on the Stream Cipher Embedded Magic Square of Random Access Files

NASA Astrophysics Data System (ADS)

Liu, Chenglian; Zhao, Jian-Ming; Rafsanjani, Marjan Kuchaki; Shen, Yijuan

2011-09-01

Magic square and stream cipher issues are both interesting and well-tried topics. In this paper, we are proposing a new scheme which streams cipher applications for random access files based on the magic square method. There are two thresholds required to secure our data, if using only decrypts by the stream cipher. It isn't to recovery original source. On other hand, we improve the model of cipher stream to strengthen and defend efficiently; it also was its own high speed and calculates to most parts of the key stream generator.

Long-term reliable physically unclonable function based on oxide tunnel barrier breakdown on two-transistors two-magnetic-tunnel-junctions cell-based embedded spin transfer torque magnetoresistive random access memory

NASA Astrophysics Data System (ADS)

Takaya, Satoshi; Tanamoto, Tetsufumi; Noguchi, Hiroki; Ikegami, Kazutaka; Abe, Keiko; Fujita, Shinobu

2017-04-01

Among the diverse applications of spintronics, security for internet-of-things (IoT) devices is one of the most important. A physically unclonable function (PUF) with a spin device (spin transfer torque magnetoresistive random access memory, STT-MRAM) is presented. Oxide tunnel barrier breakdown is used to realize long-term stability for PUFs. A secure PUF has been confirmed by evaluating the Hamming distance of a 32-bit STT-MRAM-PUF fabricated using 65 nm CMOS technology.

Enhancement of Speed Margins for 16× Digital Versatile Disc-Random Access Memory

NASA Astrophysics Data System (ADS)

Watanabe, Koichi; Minemura, Hiroyuki; Miyamoto, Makoto; Iimura, Makoto

2006-02-01

We have evaluated the speed margins of write/read 16× digital versatile disc-random access memory (DVD-RAM) test discs using write strategies for 6--16× constant angular velocity (CAV) control. Our approach is to determine the writing parameters for the middle zones by interpolating the zone numbers. Using this interpolation strategy, we successfully obtained overwrite jitter values of less than 8% and bit error rates of less than 10-5 in 6--16× DVD-RAM. Moreover, we confirmed that the speed margins were ± 20% for a 6--16× CAV.

Random Access Frame (RAF) System Neutral Buoyancy Evaluations

NASA Technical Reports Server (NTRS)

Howe, A. Scott; Polit-Casillas, Raul; Akin, David L.; McBryan, Katherine; Carlsen, Christopher

2015-01-01

The Random Access Frame (RAF) concept is a system for organizing internal layouts of space habitats, vehicles, and outposts. The RAF system is designed as a more efficient improvement over the current International Standard Payload Rack (ISPR) used on the International Space Station (ISS), which was originally designed to allow for swapping and resupply by the Space Shuttle. The RAF system is intended to be applied in variable gravity or microgravity environments. This paper discusses evaluations and results of testing the RAF system in a neutral buoyancy facility simulating low levels of gravity that might be encountered in a deep space environment.

A novel online didactic curriculum helps improve knowledge acquisition among non-emergency medicine rotating residents.

PubMed

Branzetti, Jeremy B; Aldeen, Amer Z; Foster, Andrew W; Courtney, D Mark

2011-01-01

Rotating residents represent a significant proportion of housestaff in academic emergency departments (EDs), yet they rarely receive targeted didactic education during their emergency medicine (EM) rotations. The goals of this study were: 1) to determine the effectiveness of an online didactic curriculum in improving EM knowledge among rotating residents and 2) to assess rotating resident satisfaction with this curriculum. The authors created an online lecture series of six EM subject areas targeted to rotating residents called the Northwestern University Rotating Resident Curriculum (NURRC). All rotating residents at the study site were eligible, written consent was obtained, and the study was approved by the institutional review board. Consenting participants were pretested with a 42-question multiple-choice examination and then randomized to two groups: one with access to the NURRC during the first 2 weeks of the rotation (experimental) and one without (control). Halfway through the rotation, all participants were post-tested with a different multiple-choice examination, and the controls were then granted NURRC access. The primary outcome was the difference between pretest and posttest scores (score delta). The t-test was used to compare mean scores, and a linear regression model was used to determine the association of NURRC access on score delta after adjustment for pretest type and resident type. A postintervention survey was administered at the end of the rotation to assess satisfaction with the NURRC and collect suggestions for improvement. Fifty-four rotating residents were enrolled: 29 in the experimental group and 25 in the control group. There was no significant difference in pretest scores between the two groups. Mean score delta was 17.3% in the experimental group and 1.6% in the control group, an absolute difference of 15.7% (95% confidence interval [CI]=10% to 22%). After adjustment for resident type and pretest type, the only variable positively associated with the primary outcome was NURRC access. Third-year and preliminary-year internal medicine (IM) residents demonstrated the greatest absolute improvement in score delta when granted NURRC access. Eighty percent of the participants responded to the satisfaction survey. Over 80% of the survey respondents approved of each component lecture and of the NURRC overall. After exposure to an online didactic curriculum, rotating residents demonstrated a significant increase in EM knowledge and reported a high level of satisfaction with the didactic program. © 2010 by the Society for Academic Emergency Medicine.

Structure for common access and support of fuel cell stacks

DOEpatents

Walsh, Michael M.

2000-01-01

A structure provides common support and access to multiple fuel cells externally mounted thereto. The structure has openings leading to passages defined therein for providing the access. Various other fuel cell power system components are connected at the openings, such as reactant and coolant sources.

Teaching Individuals with Profound Multiple Disabilities to Access Preferred Stimuli with Multiple Microswitches

ERIC Educational Resources Information Center

Tam, Gee May; Phillips, Katrina J.; Mudford, Oliver C.

2011-01-01

We replicated and extended previous research on microswitch facilitated choice making by individuals with profound multiple disabilities. Following an assessment of stimulus preferences, we taught 6 adults with profound multiple disabilities to emit 2 different responses to activate highly preferred stimuli. All participants learnt to activate…

Factors associated with choice of web or print intervention materials in the healthy directions 2 study.

PubMed

Greaney, Mary L; Puleo, Elaine; Bennett, Gary G; Haines, Jess; Viswanath, K; Gillman, Matthew W; Sprunck-Harrild, Kim; Coeling, Molly; Rusinak, Donna; Emmons, Karen M

2014-02-01

Many U.S. adults have multiple behavioral risk factors, and effective, scalable interventions are needed to promote population-level health. In the health care setting, interventions are often provided in print, although accessible to nearly everyone, are brief (e.g., pamphlets), are not interactive, and can require some logistics around distribution. Web-based interventions offer more interactivity but may not be accessible to all. Healthy Directions 2 was a primary care-based cluster randomized controlled trial designed to improve five behavioral cancer risk factors among a diverse sample of adults (n = 2,440) in metropolitan Boston. Intervention materials were available via print or the web. Purpose. To (a) describe the Healthy Directions 2 study design and (b) identify baseline factors associated with whether participants opted for print or web-based materials. Hierarchical regression models corrected for clustering by physician were built to examine factors associated with choice of intervention modality. At baseline, just 4.0% of participants met all behavioral recommendations. Nearly equivalent numbers of intervention participants opted for print and web-based materials (44.6% vs. 55.4%). Participants choosing web-based materials were younger, and reported having a better financial status, better perceived health, greater computer comfort, and more frequent Internet use (p < .05) than those opting for print. In addition, Whites were more likely to pick web-based material than Black participants. Interventions addressing multiple behaviors are needed in the primary care setting, but they should be available in web and print formats as nearly equal number of participants chose each option, and there are significant differences in the population groups using each modality.

The CHOICE study: a "taste-test" of utilitarian vs. leisure walking among older adults.

PubMed

Hekler, Eric B; Castro, Cynthia M; Buman, Matthew P; King, Abby C

2012-01-01

Utilitarian walking (e.g., walking for transport) and leisure walking (e.g., walking for health/recreation) are encouraged to promote health, yet few studies have explored specific preferences for these two forms of physical activity or factors that impact such preferences. A quasi-experimental crossover design was used to evaluate how training underactive midlife and older adults in each type of walking impacted total steps taken and how it was linked to their subsequent choice of walking types. Participants (N = 16) were midlife and older adults (M age = 64 ± 8 years) who were mostly women (81%) and white (75%). To control for order effects, participants were randomized to instruction in either utilitarian or leisure walking for 2 weeks and then the other type for 2 weeks. Participants then entered a 2-week "free choice" phase in which they chose any mixture of the walking types. Outcome variables included walking via OMRON pedometer and the ratio of utilitarian versus leisure walking during the free-choice phase. Participants completed surveys about their neighborhood (NEWS) and daily travel to multiple locations. Instruction in leisure-only, utilitarian-only, and a freely chosen mixture of the two each resulted in significant increases in steps taken relative to baseline (ps < 0.05). Having to go to multiple locations daily and traveling greater distances to locations were associated with engagement in more utilitarian walking. In contrast, good walking paths, neighborhood aesthetics, easy access to exercise facilities, and perceiving easier access to neighborhood services were associated with more leisure walking. Results from this pilot study suggest that midlife and older adults may most easily meet guidelines through either leisure only or a mixture of leisure and utilitarian walking, and tailored suggestions based on the person's neighborhood may be useful.

Engaging African American breast cancer survivors in an intervention trial: culture, responsiveness and community

PubMed Central

Mishel, Merle H.; Alexander, G. Rumay; Jenerette, Coretta; Blyler, Diane; Baker, Carol; Vines, Anissa I.; Green, Melissa; Long, Debra G.

2011-01-01

Introduction Younger breast cancer survivors often lead extremely busy lives with multiple demands and responsibilities, making them difficult to recruit into clinical trials. African American women are even more difficult to recruit because of additional historical and cultural barriers. In a randomized clinical trial of an intervention, we successfully used culturally informed, population-specific recruitment and retention strategies to engage younger African-American breast cancer survivors. Methods Caucasian and African American breast cancer survivors were recruited from multiple communities and sites. A variety of planned recruitment and retention strategies addressed cultural and population-specific barriers and were guided by three key principals: increasing familiarity with the study in the communities of interest; increasing the availability and accessibility of study information and study participation; and using cultural brokers. Results Accrual of younger African-American breast cancer survivors increased by 373% in 11 months. The steepest rise in the numbers of African-American women recruited came when all strategies were in place and operating simultaneously. Retention rates were 87% for both Caucasian and African American women. Discusssion/Conclusions To successfully recruit busy, younger African American cancer survivors, it is important to use a multifaceted approach, addressing cultural and racial/ethnic barriers to research participation; bridging gaps across cultures and communities; including the role of faith and beliefs in considering research participation; recognizing the demands of different life stages and economic situations and the place of research in the larger picture of peoples’ lives. Designs for recruitment and retention need to be broadly conceptualized and specifically applied. Implications for Cancer Survivors For busy cancer survivors, willingness to participate in and complete research participation is enhanced by strategies that address barriers but also acknowledge the many demands on their time by making research familiar, available, accessible and credible. PMID:20886374

Piloting an email-based resource package for job seekers with multiple sclerosis.

PubMed

Dorstyn, Diana; Roberts, Rachel; Murphy, Gregory; Kneebone, Ian; Migliorini, Christine; Craig, Ashley; Hutchinson, Claire; Field, Deborah

2017-05-01

Media-based rehabilitation provides a powerful opportunity to examine vocational behaviors in the disability sector. However, this research is preliminary at best. This paper reports pilot data. Eighteen adults with multiple sclerosis (MS) accessed an email-delivered, resource-based package, Work and MS. Pre- and post-access vocational self-efficacy and identity (Job-Procurement Self Efficacy Scale, My Vocational Situation Scale- primary outcomes), life orientation and depressed mood (Life Orientation Test - revised and Patient Health Questionnaire-9 - secondary outcomes) were assessed. Pre- and post-change scores were examined with Wilcoxon signed ranks tests and Hedges g effect sizes with associated 95% confidence intervals. Reliable change analyses were additionally calculated to determine the clinical significance of individual change scores. Significant and positive effects were reported for vocational self-efficacy, identity, and optimism. Reliable change scores in one or more of these key outcomes were reported by 30% of the sample. Satisfaction with the content and delivery of the email-based intervention was also noted. Preliminary evidence suggests that Work and MS can help to promote vocational goals, interests and strengths among job seekers with a disability by providing a set of tools, information and linkages relating to vocational pursuits and career development. Replication with a randomized control design is indicated. Implications for Rehabilitation Research indicates a high unemployment rate among working-age adults with MS. A combination of disease-specific, psychological, programmatic and societal variables contribute to employment instability in this group. This pilot study demonstrates that an e-mail-based resource package, Work and MS, provides an innovative and feasible option for promoting consumer engagement with vocational services and, potentially, improving vocational outcomes. Work and MS has potential applicability to other disability groups.

Engaging African American breast cancer survivors in an intervention trial: culture, responsiveness and community.

PubMed

Germino, Barbara B; Mishel, Merle H; Alexander, G Rumay; Jenerette, Coretta; Blyler, Diane; Baker, Carol; Vines, Anissa I; Green, Melissa; Long, Debra G

2011-03-01

Younger breast cancer survivors often lead extremely busy lives with multiple demands and responsibilities, making them difficult to recruit into clinical trials. African American women are even more difficult to recruit because of additional historical and cultural barriers. In a randomized clinical trial of an intervention, we successfully used culturally informed, population-specific recruitment and retention strategies to engage younger African-American breast cancer survivors. Caucasian and African American breast cancer survivors were recruited from multiple communities and sites. A variety of planned recruitment and retention strategies addressed cultural and population-specific barriers and were guided by three key principals: increasing familiarity with the study in the communities of interest; increasing the availability and accessibility of study information and study participation; and using cultural brokers. Accrual of younger African-American breast cancer survivors increased by 373% in 11 months. The steepest rise in the numbers of African-American women recruited came when all strategies were in place and operating simultaneously. Retention rates were 87% for both Caucasian and African American women. DISCUSSSION/CONCLUSIONS: To successfully recruit busy, younger African American cancer survivors, it is important to use a multifaceted approach, addressing cultural and racial/ethnic barriers to research participation; bridging gaps across cultures and communities; including the role of faith and beliefs in considering research participation; recognizing the demands of different life stages and economic situations and the place of research in the larger picture of peoples' lives. Designs for recruitment and retention need to be broadly conceptualized and specifically applied. For busy cancer survivors, willingness to participate in and complete research participation is enhanced by strategies that address barriers but also acknowledge the many demands on their time by making research familiar, available, accessible and credible.

Brief Report: Randomized Test of the Efficacy of Picture Exchange Communication System on Highly Generalized Picture Exchanges in Children with ASD

ERIC Educational Resources Information Center

Yoder, Paul J.; Lieberman, Rebecca G.

2010-01-01

A randomized control trial comparing two social-communication interventions in young children with autism examined far-transfer of the use of picture exchange to communicate. Thirty-six children were randomly assigned to one of two treatment conditions, one of which was the Picture Exchange Communication System (PECS). All children had access to…

Nimbus 6 Random Access Measurement System applications experiments

NASA Technical Reports Server (NTRS)

Cote, C. E. (Editor); Taylor, R. (Editor); Gilbert, E. (Editor)

1982-01-01

The advantages of a technique in which data collection platforms randomly transmit signal to a polar orbiting satellite, thus eliminating satellite interrogation are demonstrated in investigations of the atmosphere; oceanographic parameters; Arctic regions and ice conditions; navigation and position location; and data buoy development.

Effects of imputation on correlation: implications for analysis of mass spectrometry data from multiple biological matrices.

PubMed

Taylor, Sandra L; Ruhaak, L Renee; Kelly, Karen; Weiss, Robert H; Kim, Kyoungmi

2017-03-01

With expanded access to, and decreased costs of, mass spectrometry, investigators are collecting and analyzing multiple biological matrices from the same subject such as serum, plasma, tissue and urine to enhance biomarker discoveries, understanding of disease processes and identification of therapeutic targets. Commonly, each biological matrix is analyzed separately, but multivariate methods such as MANOVAs that combine information from multiple biological matrices are potentially more powerful. However, mass spectrometric data typically contain large amounts of missing values, and imputation is often used to create complete data sets for analysis. The effects of imputation on multiple biological matrix analyses have not been studied. We investigated the effects of seven imputation methods (half minimum substitution, mean substitution, k-nearest neighbors, local least squares regression, Bayesian principal components analysis, singular value decomposition and random forest), on the within-subject correlation of compounds between biological matrices and its consequences on MANOVA results. Through analysis of three real omics data sets and simulation studies, we found the amount of missing data and imputation method to substantially change the between-matrix correlation structure. The magnitude of the correlations was generally reduced in imputed data sets, and this effect increased with the amount of missing data. Significant results from MANOVA testing also were substantially affected. In particular, the number of false positives increased with the level of missing data for all imputation methods. No one imputation method was universally the best, but the simple substitution methods (Half Minimum and Mean) consistently performed poorly. © The Author 2016. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Supporting Students in Learning with Multiple Representation to Improve Student Mental Models on Atomic Structure Concepts

ERIC Educational Resources Information Center

Sunyono; Yuanita, L.; Ibrahim, M.

2015-01-01

The aim of this research is identify the effectiveness of a multiple representation-based learning model, which builds a mental model within the concept of atomic structure. The research sample of 108 students in 3 classes is obtained randomly from among students of Mathematics and Science Education Studies using a stratified random sampling…

Examining the Missing Completely at Random Mechanism in Incomplete Data Sets: A Multiple Testing Approach

ERIC Educational Resources Information Center

Raykov, Tenko; Lichtenberg, Peter A.; Paulson, Daniel

2012-01-01

A multiple testing procedure for examining implications of the missing completely at random (MCAR) mechanism in incomplete data sets is discussed. The approach uses the false discovery rate concept and is concerned with testing group differences on a set of variables. The method can be used for ascertaining violations of MCAR and disproving this…

An individual-level meta-analysis assessing the impact of community-level sanitation access on child stunting, anemia, and diarrhea: Evidence from DHS and MICS surveys.

PubMed

Larsen, David A; Grisham, Thomas; Slawsky, Erik; Narine, Lutchmie

2017-06-01

A lack of access to sanitation is an important risk factor child health, facilitating fecal-oral transmission of pathogens including soil-transmitted helminthes and various causes of diarrheal disease. We conducted a meta-analysis of cross-sectional surveys to determine the impact that community-level sanitation access has on child health for children with and without household sanitation access. Using 301 two-stage demographic health surveys and multiple indicator cluster surveys conducted between 1990 and 2015 we calculated the sanitation access in the community as the proportion of households in the sampled cluster that had household access to any type of sanitation facility. We then conducted exact matching of children based on various predictors of living in a community with high access to sanitation. Using logistic regression with the matched group as a random intercept we examined the association between the child health outcomes of stunted growth, any anemia, moderate or severe anemia, and diarrhea in the previous two weeks and the exposure of living in a community with varying degrees of community-level sanitation access. For children with household-level sanitation access, living in a community with 100% sanitation access was associated with lowered odds of stunting (adjusted odds ratio [AOR] = 0.97, 95%; confidence interval (CI) = 0.94-1.00; n = 14,153 matched groups, 1,175,167 children), any anemia (AOR = 0.73; 95% CI = 0.67-0.78; n = 5,319 matched groups, 299,033 children), moderate or severe anemia (AOR = 0.72, 95% CI = 0.68-0.77; n = 5,319 matched groups, 299,033 children) and diarrhea (AOR = 0.94; 95% CI = 0.91-0.97); n = 16,379 matched groups, 1,603,731 children) compared to living in a community with < 30% sanitation access. For children without household-level sanitation access, living in communities with 0% sanitation access was associated with higher odds of stunting (AOR = 1.04, 95% CI = 1.02-1.06; n = 14,153 matched groups, 1,175,167 children), any anemia (AOR = 1.05, 95% CI = 1.00-1.09; n = 5,319 matched groups, 299,033 children), moderate or severe anemia (AOR = 1.04, 95% CI = 1.00-1.09; n = 5,319 matched groups, 299,033 children) but not diarrhea (AOR = 1.00, 95% CI = 0.98-1.02; n = 16,379 matched groups, 1,603,731 children) compared to children without household-level sanitation access living in communities with 1-30% sanitation access. Community-level sanitation access is associated with improved child health outcomes independent of household-level sanitation access. The proportion of children living in communities with 100% sanitation access throughout the world is appallingly low. Ensuring sanitation access to all by 2030 will greatly improve child health.

Deviation from the law of energy equipartition in a small dynamic-random-access memory

NASA Astrophysics Data System (ADS)

Carles, Pierre-Alix; Nishiguchi, Katsuhiko; Fujiwara, Akira

2015-06-01

A small dynamic-random-access memory (DRAM) coupled with a high charge sensitivity electrometer based on a silicon field-effect transistor is used to study the law of equipartition of energy. By statistically analyzing the movement of single electrons in the DRAM at various temperature and voltage conditions in thermal equilibrium, we are able to observe a behavior that differs from what is predicted by the law of equipartition energy: when the charging energy of the capacitor of the DRAM is comparable to or smaller than the thermal energy kBT/2, random electron motion is ruled perfectly by thermal energy; on the other hand, when the charging energy becomes higher in relation to the thermal energy kBT/2, random electron motion is suppressed which indicates a deviation from the law of equipartition of energy. Since the law of equipartition is analyzed using the DRAM, one of the most familiar devices, we believe that our results are perfectly universal among all electronic devices.

Racial and Sociodemographic Disparities in Internet Access and eHealth Intervention Utilization Among Veteran Smokers.

PubMed

Calhoun, Patrick S; Wilson, Sarah M; Hicks, Terrell A; Thomas, Shaun P; Dedert, Eric A; Hair, Lauren P; Bastian, Lori A; Beckham, Jean C

2016-09-15

Access to the internet at home may be an important barrier to electronic health (eHealth) smoking cessation interventions. The current study explored possible sociodemographic disparities in access to the internet at home among veteran smokers. Data from participants proactively recruited and enrolled in a randomized smoking cessation effectiveness trial (N = 408) that compared a web-based smoking cessation intervention to Veterans Affairs (VA) usual care were used to examine the demographic attributes of smokers with and without internet access at home. Multivariable logistic regression was used to examine associations between demographic factors and home internet access. Data from patients randomized to the internet arm of the study (N = 205) were used to ascertain correlates of utilization of the intervention website. While the majority of the sample (82 %) endorsed access to the internet at home, veterans who were African-American, older, and not married were significantly less likely to have home internet access. Veterans who were African-American, older, less educated, had longer travel times to the nearest VA facility, and increased nicotine dependence were less likely to access the internet on a daily basis. While several sociodemographic variables (e.g., age, race, education, employment) were related to utilization of a free membership to a commercial, web-based smoking cessation intervention in bivariate analyses, only access to the internet at home was related to use of the smoking cessation site in adjusted results. These results highlight gaps in internet access and use among veterans and additionally underscore the importance of improving accessibility of eHealth interventions for low-income, minority, and socially disadvantaged veteran populations.

Beam Design and User Scheduling for Nonorthogonal Multiple Access With Multiple Antennas Based on Pareto Optimality

NASA Astrophysics Data System (ADS)

Seo, Junyeong; Sung, Youngchul

2018-06-01

In this paper, an efficient transmit beam design and user scheduling method is proposed for multi-user (MU) multiple-input single-output (MISO) non-orthogonal multiple access (NOMA) downlink, based on Pareto-optimality. The proposed beam design and user scheduling method groups simultaneously-served users into multiple clusters with practical two users in each cluster, and then applies spatical zeroforcing (ZF) across clusters to control inter-cluster interference (ICI) and Pareto-optimal beam design with successive interference cancellation (SIC) to two users in each cluster to remove interference to strong users and leverage signal-to-interference-plus-noise ratios (SINRs) of interference-experiencing weak users. The proposed method has flexibility to control the rates of strong and weak users and numerical results show that the proposed method yields good performance.

Implementing a low-cost web-based clinical trial management system for community studies: a case study.

PubMed

Geyer, John; Myers, Kathleen; Vander Stoep, Ann; McCarty, Carolyn; Palmer, Nancy; DeSalvo, Amy

2011-10-01

Clinical trials with multiple intervention locations and a single research coordinating center can be logistically difficult to implement. Increasingly, web-based systems are used to provide clinical trial support with many commercial, open source, and proprietary systems in use. New web-based tools are available which can be customized without programming expertise to deliver web-based clinical trial management and data collection functions. To demonstrate the feasibility of utilizing low-cost configurable applications to create a customized web-based data collection and study management system for a five intervention site randomized clinical trial establishing the efficacy of providing evidence-based treatment via teleconferencing to children with attention-deficit hyperactivity disorder. The sites are small communities that would not usually be included in traditional randomized trials. A major goal was to develop database that participants could access from computers in their home communities for direct data entry. Discussed is the selection process leading to the identification and utilization of a cost-effective and user-friendly set of tools capable of customization for data collection and study management tasks. An online assessment collection application, template-based web portal creation application, and web-accessible Access 2007 database were selected and customized to provide the following features: schedule appointments, administer and monitor online secure assessments, issue subject incentives, and securely transmit electronic documents between sites. Each tool was configured by users with limited programming expertise. As of June 2011, the system has successfully been used with 125 participants in 5 communities, who have completed 536 sets of assessment questionnaires, 8 community therapists, and 11 research staff at the research coordinating center. Total automation of processes is not possible with the current set of tools as each is loosely affiliated, creating some inefficiency. This system is best suited to investigations with a single data source e.g., psychosocial questionnaires. New web-based applications can be used by investigators with limited programming experience to implement user-friendly, efficient, and cost-effective tools for multi-site clinical trials with small distant communities. Such systems allow the inclusion in research of populations that are not usually involved in clinical trials.

A DTN-Based Multiple Access Fast Forward Service for the NASA Space Network

NASA Technical Reports Server (NTRS)

Israel, David; Davis, Faith; Marquart. Jane

2011-01-01

The NASA Space Network provides a demand access return link service capable of providing users a space link "on demand". An equivalent service in the forward link direction is not possible due to Tracking and Data Relay Spacecraft (TDRS) constraints. A Disruption Tolerant Networking (DTN)-based Multiple Access Fast Forward (MAFF) service has been proposed to provide a forward link to a user as soon as possible. Previous concept studies have identified a basic architecture and implementation approach. This paper reviews the user scenarios and benefits of an MAFF service and proposes an implementation approach based on the use of DTN protocols.

A Rewritable, Random-Access DNA-Based Storage System.

PubMed

Yazdi, S M Hossein Tabatabaei; Yuan, Yongbo; Ma, Jian; Zhao, Huimin; Milenkovic, Olgica

2015-09-18

We describe the first DNA-based storage architecture that enables random access to data blocks and rewriting of information stored at arbitrary locations within the blocks. The newly developed architecture overcomes drawbacks of existing read-only methods that require decoding the whole file in order to read one data fragment. Our system is based on new constrained coding techniques and accompanying DNA editing methods that ensure data reliability, specificity and sensitivity of access, and at the same time provide exceptionally high data storage capacity. As a proof of concept, we encoded parts of the Wikipedia pages of six universities in the USA, and selected and edited parts of the text written in DNA corresponding to three of these schools. The results suggest that DNA is a versatile media suitable for both ultrahigh density archival and rewritable storage applications.

A Rewritable, Random-Access DNA-Based Storage System

NASA Astrophysics Data System (ADS)

Tabatabaei Yazdi, S. M. Hossein; Yuan, Yongbo; Ma, Jian; Zhao, Huimin; Milenkovic, Olgica

2015-09-01

We describe the first DNA-based storage architecture that enables random access to data blocks and rewriting of information stored at arbitrary locations within the blocks. The newly developed architecture overcomes drawbacks of existing read-only methods that require decoding the whole file in order to read one data fragment. Our system is based on new constrained coding techniques and accompanying DNA editing methods that ensure data reliability, specificity and sensitivity of access, and at the same time provide exceptionally high data storage capacity. As a proof of concept, we encoded parts of the Wikipedia pages of six universities in the USA, and selected and edited parts of the text written in DNA corresponding to three of these schools. The results suggest that DNA is a versatile media suitable for both ultrahigh density archival and rewritable storage applications.

Ah!Help: A generalized on-line help facility

NASA Technical Reports Server (NTRS)

Yu, Wong Nai; Mantooth, Charmiane; Soulahakil, Alex

1986-01-01

The idea behind the help facility discussed is relatively simple. It is made unique by the fact that it is written in Ada and uses aspects of the language which make information retrieval rapid and simple. Specifically, the DIRECT IO facility allows for random access into the help files. It is necessary to discuss the advantages of random access over sequential access. The mere fact that the program in written in Ada implies a saving in terms of lines of code. This introduces the possibility of eventually adapting the program to run at the microcomputer level, a major consideration . Additionally, since the program uses only standard Ada generics, it is portable to other systems. This is another aspect which must always be taken into consideration in writting any software package in the modern day world of computer programming.

Contrast use in relation to the arterial access site for percutaneous coronary intervention: A comprehensive meta-analysis of randomized trials

PubMed Central

Shah, Rahman; Mattox, Anthony; Khan, M Rehan; Berzingi, Chalak; Rashid, Abdul

2017-01-01

AIM To compare the amount of contrast used during percutaneous coronary intervention (PCI) via trans-radial access (TRA) vs trans-femoral access (TFA). METHODS Scientific databases and websites were searched for:randomizedcontrolledtrials (RCTs). Data were extracted by two independent reviewers and was summarized as the weighted mean difference (WMD) of contrast used with a 95%CI using a random-effects model. RESULTS The meta-analysis included 13 RCTs with a total of 3165 patients. There was no difference between the two strategies in the amount of contrast used (WMD = - 0.65 mL, 95%CI: -10.94-9.46 mL; P = 0.901). CONCLUSION This meta-analysis shows that in patients undergoing PCI, the amount of contrast volume used was not different between TRA and TFA. PMID:28515857

Non-volatile, high density, high speed, Micromagnet-Hall effect Random Access Memory (MHRAM)

NASA Technical Reports Server (NTRS)

Wu, Jiin C.; Katti, Romney R.; Stadler, Henry L.

1991-01-01

The micromagnetic Hall effect random access memory (MHRAM) has the potential of replacing ROMs, EPROMs, EEPROMs, and SRAMs because of its ability to achieve non-volatility, radiation hardness, high density, and fast access times, simultaneously. Information is stored magnetically in small magnetic elements (micromagnets), allowing unlimited data retention time, unlimited numbers of rewrite cycles, and inherent radiation hardness and SEU immunity, making the MHRAM suitable for ground based as well as spaceflight applications. The MHRAM device design is not affected by areal property fluctuations in the micromagnet, so high operating margins and high yield can be achieved in large scale integrated circuit (IC) fabrication. The MHRAM has short access times (less than 100 nsec). Write access time is short because on-chip transistors are used to gate current quickly, and magnetization reversal in the micromagnet can occur in a matter of a few nanoseconds. Read access time is short because the high electron mobility sensor (InAs or InSb) produces a large signal voltage in response to the fringing magnetic field from the micromagnet. High storage density is achieved since a unit cell consists only of two transistors and one micromagnet Hall effect element. By comparison, a DRAM unit cell has one transistor and one capacitor, and a SRAM unit cell has six transistors.

Multiple Imputation of a Randomly Censored Covariate Improves Logistic Regression Analysis.

PubMed

Atem, Folefac D; Qian, Jing; Maye, Jacqueline E; Johnson, Keith A; Betensky, Rebecca A

2016-01-01

Randomly censored covariates arise frequently in epidemiologic studies. The most commonly used methods, including complete case and single imputation or substitution, suffer from inefficiency and bias. They make strong parametric assumptions or they consider limit of detection censoring only. We employ multiple imputation, in conjunction with semi-parametric modeling of the censored covariate, to overcome these shortcomings and to facilitate robust estimation. We develop a multiple imputation approach for randomly censored covariates within the framework of a logistic regression model. We use the non-parametric estimate of the covariate distribution or the semiparametric Cox model estimate in the presence of additional covariates in the model. We evaluate this procedure in simulations, and compare its operating characteristics to those from the complete case analysis and a survival regression approach. We apply the procedures to an Alzheimer's study of the association between amyloid positivity and maternal age of onset of dementia. Multiple imputation achieves lower standard errors and higher power than the complete case approach under heavy and moderate censoring and is comparable under light censoring. The survival regression approach achieves the highest power among all procedures, but does not produce interpretable estimates of association. Multiple imputation offers a favorable alternative to complete case analysis and ad hoc substitution methods in the presence of randomly censored covariates within the framework of logistic regression.

A descriptive study of access to services in a random sample of Canadian rural emergency departments.

PubMed

Fleet, Richard; Poitras, Julien; Maltais-Giguère, Julie; Villa, Julie; Archambault, Patrick

2013-11-27

To examine 24/7 access to services and consultants in a sample of Canadian rural emergency departments (EDs). Cross-sectional study-mixed methods (structured interview, survey and government data bases) with random sampling of hospitals. Canadian rural EDs (rural small town (RST) definition-Statistics Canada). 28% (95/336) of Canadian rural EDs providing 24/7 physician coverage located in hospitals with acute care hospitalisation beds. General characteristics of the rural EDs, information about 24/7 access to consultants, equipment and services, and the proportion of rural hospitals more than 300 km from levels 1 and 2 trauma centres. Of the 336 rural EDs identified, 122 (36%) were randomly selected and contacted. Overall, 95 EDs participated in the study (participation rate, 78%). Hospitals had, on an average, 23 acute care beds, 7 ED stretchers and 13 500 annual ED visits. The proportion of rural hospitals with local access to the following 24/7 services was paediatrician, 5%; obstetrician, 10%; psychiatrist, 11%; internist, 12%; intensive care unit, 17%; CT scanner, 20%; surgeon, 26%; ultrasound, 28%; basic X-ray, 97% and laboratory services, 99%. Forty-four per cent and 54% of the RST EDs were more than 300 km from a level 1 and level 2 trauma centre, respectively. This is the first study describing the services available in Canadian rural EDs. Apart from basic laboratory and X-ray services, most rural EDs have limited access to consultants, advanced imaging and critical care services. A detailed study is needed to evaluate the impact of these limited services on patient outcomes, costs and interfacility transport demands.

Mapping of RNA accessible sites by extension of random oligonucleotide libraries with reverse transcriptase.

PubMed Central

Allawi, H T; Dong, F; Ip, H S; Neri, B P; Lyamichev, V I

2001-01-01

A rapid and simple method for determining accessible sites in RNA that is independent of the length of target RNA and does not require RNA labeling is described. In this method, target RNA is allowed to hybridize with sequence-randomized libraries of DNA oligonucleotides linked to a common tag sequence at their 5'-end. Annealed oligonucleotides are extended with reverse transcriptase and the extended products are then amplified by using PCR with a primer corresponding to the tag sequence and a second primer specific to the target RNA sequence. We used the combination of both the lengths of the RT-PCR products and the location of the binding site of the RNA-specific primer to determine which regions of the RNA molecules were RNA extendible sites, that is, sites available for oligonucleotide binding and extension. We then employed this reverse transcription with the random oligonucleotide libraries (RT-ROL) method to determine the accessible sites on four mRNA targets, human activated ras (ha-ras), human intercellular adhesion molecule-1 (ICAM-1), rabbit beta-globin, and human interferon-gamma (IFN-gamma). Our results were concordant with those of other researchers who had used RNase H cleavage or hybridization with arrays of oligonucleotides to identify accessible sites on some of these targets. Further, we found good correlation between sites when we compared the location of extendible sites identified by RT-ROL with hybridization sites of effective antisense oligonucleotides on ICAM-1 mRNA in antisense inhibition studies. Finally, we discuss the relationship between RNA extendible sites and RNA accessibility. PMID:11233988

Compliance with youth access regulations for indoor UV tanning.

PubMed

Hester, Eric J; Heilig, Lauren F; D'Ambrosia, Renee; Drake, Amanda L; Schilling, Lisa M; Dellavalle, Robert P

2005-08-01

To describe youth access to indoor UV tanning and youth discount pricing incentives in 4 states with different age restrictions: Colorado (no age restrictions), Texas (age 13 years), Illinois (age 14 years), and Wisconsin (age 16 years). Cross-sectional telephone survey conducted in October 2003 using a standardized script to assess the practices of randomly selected UV tanning operators. Randomly selected licensed indoor UV tanning facility operators in Colorado, Texas, Illinois, and Wisconsin. Number of facilities (1) complying with indoor UV tanning minimum age regulations for a 12-year-old potential patron and a 15-year-old potential patron and (2) offering youth discounts. For a 12-year-old potential patron, 62% of facilities in states with minimum age restrictions prohibiting 12-year-olds had an operator report that they would not permit indoor tanning (Texas, 23%; Illinois, 74%; and Wisconsin, 89%) compared with 18% in Colorado, a state without youth access regulations. For a 15-year-old patron, most facilities in Wisconsin, the only state with a minimum age restriction for 15-year-olds, prohibited access (77%). Overall, 15% of operators offered youth discounts: Texas, 23%; Illinois, 14%; Wisconsin, 11%; and Colorado, 11%. Tanning facilities in 4 states offered price incentives directed at youths. State youth access regulations were associated with decreased youth access to indoor tanning. High compliance levels in states with long-standing youth access regulations (Illinois and Wisconsin) demonstrate the potential for successful tanning industry youth access regulation.

Case Study in Modeling Accessibility for Online Instruction

ERIC Educational Resources Information Center

Conway, Thomas Hayes

2017-01-01

The purpose of this qualitative multiple case study was to explore how accessibility standards are adapted to create online learning environments that are accessible to people who use assistive technology, or have navigational challenges due to physical or intellectual disabilities. Rogers diffusion of innovation was used as the contextual…

Identity and Access Management: Technological Implementation of Policy

ERIC Educational Resources Information Center

von Munkwitz-Smith, Jeff; West, Ann

2004-01-01

Navigating the multiple processes for accessing ever-multiplying campus information systems can be a daunting task for students, faculty, and staff. This article provides a brief overview of Identity and Access Management Services. The authors review key characteristics and components of this new information architecture and address the issue of…

Study of optoelectronic switch for satellite-switched time-division multiple access

NASA Technical Reports Server (NTRS)

Su, Shing-Fong; Jou, Liz; Lenart, Joe

1987-01-01

The use of optoelectronic switching for satellite switched time division multiple access will improve the isolation and reduce the crosstalk of an IF switch matrix. The results are presented of a study on optoelectronic switching. Tasks include literature search, system requirements study, candidate switching architecture analysis, and switch model optimization. The results show that the power divided and crossbar switching architectures are good candidates for an IF switch matrix.

MCNP6 Fission Multiplicity with FMULT Card

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilcox, Trevor; Fensin, Michael Lorne; Hendricks, John S.

With the merger of MCNPX and MCNP5 into MCNP6, MCNP6 now provides all the capabilities of both codes allowing the user to access all the fission multiplicity data sets. Detailed in this paper is: (1) the new FMULT card capabilities for accessing these different data sets; (2) benchmark calculations, as compared to experiment, detailing the results of selecting these separate data sets for thermal neutron induced fission on U-235.

Maritime Analytics Prototype: Final Development Report

DTIC Science & Technology

2014-04-01

access management platform OpenAM , support for multiple instances of the same type of widget and support for installation specific configuration files to...et de la gestion de l’accès OpenAM , le support pour plusieurs instances du même type de widget et le support des fichiers d’installation de...open source authentication and access management platform OpenAM , support for multiple instances of the same type of widget and support for

Coherent direct sequence optical code multiple access encoding-decoding efficiency versus wavelength detuning.

PubMed

Pastor, D; Amaya, W; García-Olcina, R; Sales, S

2007-07-01

We present a simple theoretical model of and the experimental verification for vanishing of the autocorrelation peak due to wavelength detuning on the coding-decoding process of coherent direct sequence optical code multiple access systems based on a superstructured fiber Bragg grating. Moreover, the detuning vanishing effect has been explored to take advantage of this effect and to provide an additional degree of multiplexing and/or optical code tuning.

On the performance of a code division multiple access scheme with transmit/receive conflicts

NASA Astrophysics Data System (ADS)

Silvester, J. A.

One of the benefits of spread spectrum is that by assigning each user a different orthogonal signal set, multiple transmissions can occur simultaneously. This possibility is utilized in new access schemes called Code Division Multiple Access (CDMA). The present investigation is concerned with a particular CDMA implementation in which the transmit times for each symbol are exactly determined in a distributed manner such that both sender and receiver know them. In connection with a decision whether to transmit or receive, the loss of a symbol in one of the channels results. The system employs thus a coding technique which permits correct decoding of a codeword even if some constituent symbols are missing or in error. The technique used is Reed Solomon coding. The performance of this system is analyzed, and attention is given to the optimum strategy which should be used in deciding whether to receive or transmit.

The relationships of 'ecstasy' (MDMA) and cannabis use to impaired executive inhibition and access to semantic long-term memory.

PubMed

Murphy, Philip N; Erwin, Philip G; Maciver, Linda; Fisk, John E; Larkin, Derek; Wareing, Michelle; Montgomery, Catharine; Hilton, Joanne; Tames, Frank J; Bradley, Belinda; Yanulevitch, Kate; Ralley, Richard

2011-10-01

This study aimed to examine the relationship between the consumption of ecstasy (3,4-methylenedioxymethamphetamine (MDMA)) and cannabis, and performance on the random letter generation task which generates dependent variables drawing upon executive inhibition and access to semantic long-term memory (LTM). The participant group was a between-participant independent variable with users of both ecstasy and cannabis (E/C group, n = 15), users of cannabis but not ecstasy (CA group, n = 13) and controls with no exposure to these drugs (CO group, n = 12). Dependent variables measured violations of randomness: number of repeat sequences, number of alphabetical sequences (both drawing upon inhibition) and redundancy (drawing upon access to semantic LTM). E/C participants showed significantly higher redundancy than CO participants but did not differ from CA participants. There were no significant effects for the other dependent variables. A regression model comprising intelligence measures and estimates of ecstasy and cannabis consumption predicted redundancy scores, but only cannabis consumption contributed significantly to this prediction. Impaired access to semantic LTM may be related to cannabis consumption, although the involvement of ecstasy and other stimulant drugs cannot be excluded here. Executive inhibitory functioning, as measured by the random letter generation task, is unrelated to ecstasy and cannabis consumption. Copyright © 2011 John Wiley & Sons, Ltd.

Subcritical Multiplicative Chaos for Regularized Counting Statistics from Random Matrix Theory

NASA Astrophysics Data System (ADS)

Lambert, Gaultier; Ostrovsky, Dmitry; Simm, Nick

2018-05-01

For an {N × N} Haar distributed random unitary matrix U N , we consider the random field defined by counting the number of eigenvalues of U N in a mesoscopic arc centered at the point u on the unit circle. We prove that after regularizing at a small scale {ɛN > 0}, the renormalized exponential of this field converges as N \\to ∞ to a Gaussian multiplicative chaos measure in the whole subcritical phase. We discuss implications of this result for obtaining a lower bound on the maximum of the field. We also show that the moments of the total mass converge to a Selberg-like integral and by taking a further limit as the size of the arc diverges, we establish part of the conjectures in Ostrovsky (Nonlinearity 29(2):426-464, 2016). By an analogous construction, we prove that the multiplicative chaos measure coming from the sine process has the same distribution, which strongly suggests that this limiting object should be universal. Our approach to the L 1-phase is based on a generalization of the construction in Berestycki (Electron Commun Probab 22(27):12, 2017) to random fields which are only asymptotically Gaussian. In particular, our method could have applications to other random fields coming from either random matrix theory or a different context.

Heuristic query optimization for query multiple table and multiple clausa on mobile finance application

NASA Astrophysics Data System (ADS)

Indrayana, I. N. E.; P, N. M. Wirasyanti D.; Sudiartha, I. KG

2018-01-01

Mobile application allow many users to access data from the application without being limited to space, space and time. Over time the data population of this application will increase. Data access time will cause problems if the data record has reached tens of thousands to millions of records.The objective of this research is to maintain the performance of data execution for large data records. One effort to maintain data access time performance is to apply query optimization method. The optimization used in this research is query heuristic optimization method. The built application is a mobile-based financial application using MySQL database with stored procedure therein. This application is used by more than one business entity in one database, thus enabling rapid data growth. In this stored procedure there is an optimized query using heuristic method. Query optimization is performed on a “Select” query that involves more than one table with multiple clausa. Evaluation is done by calculating the average access time using optimized and unoptimized queries. Access time calculation is also performed on the increase of population data in the database. The evaluation results shown the time of data execution with query heuristic optimization relatively faster than data execution time without using query optimization.

Small individual loans and mental health: a randomized controlled trial among South African adults

PubMed Central

Fernald, Lia CH; Hamad, Rita; Karlan, Dean; Ozer, Emily J; Zinman, Jonathan

2008-01-01

Background In the developing world, access to small, individual loans has been variously hailed as a poverty-alleviation tool – in the context of "microcredit" – but has also been criticized as "usury" and harmful to vulnerable borrowers. Prior studies have assessed effects of access to credit on traditional economic outcomes for poor borrowers, but effects on mental health have been largely ignored. Methods Applicants who had previously been rejected (n = 257) for a loan (200% annual percentage rate – APR) from a lender in South Africa were randomly assigned to a "second-look" that encouraged loan officers to approve their applications. This randomized encouragement resulted in 53% of applicants receiving a loan they otherwise would not have received. All subjects were assessed 6–12 months later with questions about demographics, socio-economic status, and two indicators of mental health: the Center for Epidemiologic Studies – Depression Scale (CES-D) and Cohen's Perceived Stress scale. Intent-to-treat analyses were calculated using multinomial probit regressions. Results Randomization into receiving a "second look" for access to credit increased perceived stress in the combined sample of women and men; the findings were stronger among men. Credit access was associated with reduced depressive symptoms in men, but not women. Conclusion Our findings suggest that a mechanism used to reduce the economic stress of extremely poor individuals can have mixed effects on their experiences of psychological stress and depressive symptomatology. Our data support the notion that mental health should be included as a measure of success (or failure) when examining potential tools for poverty alleviation. Further longitudinal research is needed in South Africa and other settings to understand how borrowing at high interest rates affects gender roles and daily life activities. CCT: ISRCTN 10734925 PMID:19087316

Small individual loans and mental health: a randomized controlled trial among South African adults.

PubMed

Fernald, Lia C H; Hamad, Rita; Karlan, Dean; Ozer, Emily J; Zinman, Jonathan

2008-12-16

In the developing world, access to small, individual loans has been variously hailed as a poverty-alleviation tool - in the context of "microcredit" - but has also been criticized as "usury" and harmful to vulnerable borrowers. Prior studies have assessed effects of access to credit on traditional economic outcomes for poor borrowers, but effects on mental health have been largely ignored. Applicants who had previously been rejected (n = 257) for a loan (200% annual percentage rate - APR) from a lender in South Africa were randomly assigned to a "second-look" that encouraged loan officers to approve their applications. This randomized encouragement resulted in 53% of applicants receiving a loan they otherwise would not have received. All subjects were assessed 6-12 months later with questions about demographics, socio-economic status, and two indicators of mental health: the Center for Epidemiologic Studies - Depression Scale (CES-D) and Cohen's Perceived Stress scale. Intent-to-treat analyses were calculated using multinomial probit regressions. Randomization into receiving a "second look" for access to credit increased perceived stress in the combined sample of women and men; the findings were stronger among men. Credit access was associated with reduced depressive symptoms in men, but not women. Our findings suggest that a mechanism used to reduce the economic stress of extremely poor individuals can have mixed effects on their experiences of psychological stress and depressive symptomatology. Our data support the notion that mental health should be included as a measure of success (or failure) when examining potential tools for poverty alleviation. Further longitudinal research is needed in South Africa and other settings to understand how borrowing at high interest rates affects gender roles and daily life activities. CCT: ISRCTN 10734925.

Fitness for duty in the nuclear power industry: Annual summary of program performance reports CY 1994. Volume 5

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westra, C.; Durbin, N.; Field, I.

This report summarizes the data from the semiannual reports on fitness-for-duty programs submitted to the NRC by utilities for two reporting periods: January 1 through June 30, 1994, and July I through December 31, 1994. During 1994, licensees reported that they had conducted 163,241 tests for the presence of illegal drugs and alcohol. Of these tests, 1,372 (.84%) were confirmed positive. Positive test results varied by category of test and category of worker. The majority of positive test results (977) were obtained through pre-access testing. Of tests conducted on workers having access to the protected area, there were 223 positivemore » tests from random testing and 122 positive tests from for-cause testing. Follow-up testing of workers who had previously tested positive resulted in 50 positive tests. For-cause testing resulted in the highest percentage of positive tests; about 16 percent of for-cause tests were positive. This compares with a positive test rate of 1.22 percent of pre-access tests and .28 percent of random tests. The positive test rate for badged workers (including only random, for-cause, and follow-up test results) was .48 percent. Positive test rates also varied by category of worker. When all types of tests are combined (pre-access, random, for-cause, and follow-up testing), short-term contractor personnel had the highest positive test rate at 1.22 percent. Licensee employees and long-term contractors had lower combined positive test rates (.33% and .49%, respectively). Of the substances tested, marijuana was responsible for the highest percentage of positive test results (52.07%), followed by cocaine (24.25%) and alcohol (17.45%).« less

Employing online quantum random number generators for generating truly random quantum states in Mathematica

NASA Astrophysics Data System (ADS)

Miszczak, Jarosław Adam

2013-01-01

The presented package for the Mathematica computing system allows the harnessing of quantum random number generators (QRNG) for investigating the statistical properties of quantum states. The described package implements a number of functions for generating random states. The new version of the package adds the ability to use the on-line quantum random number generator service and implements new functions for retrieving lists of random numbers. Thanks to the introduced improvements, the new version provides faster access to high-quality sources of random numbers and can be used in simulations requiring large amount of random data. New version program summaryProgram title: TRQS Catalogue identifier: AEKA_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKA_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 18 134 No. of bytes in distributed program, including test data, etc.: 2 520 49 Distribution format: tar.gz Programming language: Mathematica, C. Computer: Any supporting Mathematica in version 7 or higher. Operating system: Any platform supporting Mathematica; tested with GNU/Linux (32 and 64 bit). RAM: Case-dependent Supplementary material: Fig. 1 mentioned below can be downloaded. Classification: 4.15. External routines: Quantis software library (http://www.idquantique.com/support/quantis-trng.html) Catalogue identifier of previous version: AEKA_v1_0 Journal reference of previous version: Comput. Phys. Comm. 183(2012)118 Does the new version supersede the previous version?: Yes Nature of problem: Generation of random density matrices and utilization of high-quality random numbers for the purpose of computer simulation. Solution method: Use of a physical quantum random number generator and an on-line service providing access to the source of true random numbers generated by quantum real number generator. Reasons for new version: Added support for the high-speed on-line quantum random number generator and improved methods for retrieving lists of random numbers. Summary of revisions: The presented version provides two signicant improvements. The first one is the ability to use the on-line Quantum Random Number Generation service developed by PicoQuant GmbH and the Nano-Optics groups at the Department of Physics of Humboldt University. The on-line service supported in the version 2.0 of the TRQS package provides faster access to true randomness sources constructed using the laws of quantum physics. The service is freely available at https://qrng.physik.hu-berlin.de/. The use of this service allows using the presented package with the need of a physical quantum random number generator. The second improvement introduced in this version is the ability to retrieve arrays of random data directly for the used source. This increases the speed of the random number generation, especially in the case of an on-line service, where it reduces the time necessary to establish the connection. Thanks to the speed improvement of the presented version, the package can now be used in simulations requiring larger amounts of random data. Moreover, the functions for generating random numbers provided by the current version of the package more closely follow the pattern of functions for generating pseudo- random numbers provided in Mathematica. Additional comments: Speed comparison: The implementation of the support for the QRNG on-line service provides a noticeable improvement in the speed of random number generation. For the samples of real numbers of size 101; 102,…,107 the times required to generate these samples using Quantis USB device and QRNG service are compared in Fig. 1. The presented results show that the use of the on-line service provides faster access to random numbers. One should note, however, that the speed gain can increase or decrease depending on the connection speed between the computer and the server providing random numbers. Running time: Depends on the used source of randomness and the amount of random data used in the experiment. References: [1] M. Wahl, M. Leifgen, M. Berlin, T. Röhlicke, H.-J. Rahn, O. Benson., An ultrafast quantum random number generator with provably bounded output bias based on photon arrival time measurements, Applied Physics Letters, Vol. 098, 171105 (2011). http://dx.doi.org/10.1063/1.3578456.

Cognitive-behavioral therapy for patients with irritable bowel syndrome: current insights.

PubMed

Kinsinger, Sarah W

2017-01-01

Irritable bowel syndrome (IBS) is a chronic gastrointestinal (GI) condition associated with significant health care utilization and quality-of-life impairment. Latest research indicates that the brain-gut axis plays a key role in the disorder, and the presence of psychological factors and central processing deficits contribute to symptom severity and disability. Psychological therapies as a whole have demonstrated good efficacy in reducing the severity of IBS symptoms. Cognitive-behavioral therapy (CBT) has been tested most rigorously in multiple randomized controlled trials and consistently demonstrates significant and durable effects on IBS symptoms and quality of life. Various protocols for treating IBS have been developed, and most recent advances in the field include exposure-based treatments to target symptom-specific anxiety as well as modified delivery methods, including internet-based treatment models. Despite the well-documented advantages of CBT for IBS, it has been poorly disseminated and few patients have access to this treatment. The primary barrier to dissemination is the limited number of therapists with adequate training in GI psychology to provide this evidence-based intervention. Future developments in the field need to focus on training opportunities to equip more therapists to competently provide CBT for this population. Further efforts to develop telemedicine platforms for delivering this intervention will also improve accessibility for patients.

Progress with infliximab biosimilars for inflammatory bowel disease.

PubMed

Kurti, Zsuzsanna; Gonczi, Lorant; Lakatos, Peter L

2018-04-29

Biological therapies have revolutionized the treatment of inflammatory bowel diseases (IBD) in the last two decades. Though biological drugs are effective, their use is associated with high costs and access to biological agents varies among countries. As the patent for the reference products expired, the advent of biosimilar monoclonal antibodies has been expected. Biosimilars represent less expensive alternatives compared to the reference product. Areas covered: In this review, authors will review the literature on the clinical efficacy, safety and immunogenicity of current and future biosimilar infliximabs. Short- and medium-term data from real-life cohorts and from randomized-clinical trials in IBD demonstrated similar outcomes in terms of efficacy, safety and immunogenicity as the reference product for CT-P13. Switch data from the reference to the biosimilar product are also accumulating (including the NOR-SWITCH and the CT-P13 3.4 study). Expert opinion: The use of biosimilar infliximab in IBD is increasing worldwide. Its use may be associated with budget savings leading to better access to biological therapies and consequently improved health outcomes. Switching from the originator to a biosimilar in patients with IBD is acceptable, although scientific and clinical evidence is lacking regarding reverse switching, multiple switching, and cross-switching among biosimilars in IBD patients.

CACAO (THEOBROMA CACAO L.) GENETIC RESOURCES RESEARCH AT THE USDA-ARS TROPICAL AGRICULTURE RESEARCH STATION

USDA-ARS?s Scientific Manuscript database

The current USDA ARS Tropical Agriculture Research Station’s cacao (Theobroma cacao) collection consists of 154 clonally propagated accessions. Each accession is represented by six individual trees grafted on Amelonado rootstocks and planted in a completely randomized block design with three blocks...

Feedback Power Control Strategies in Wireless Sensor Networks with Joint Channel Decoding

PubMed Central

Abrardo, Andrea; Ferrari, Gianluigi; Martalò, Marco; Perna, Fabio

2009-01-01

In this paper, we derive feedback power control strategies for block-faded multiple access schemes with correlated sources and joint channel decoding (JCD). In particular, upon the derivation of the feasible signal-to-noise ratio (SNR) region for the considered multiple access schemes, i.e., the multidimensional SNR region where error-free communications are, in principle, possible, two feedback power control strategies are proposed: (i) a classical feedback power control strategy, which aims at equalizing all link SNRs at the access point (AP), and (ii) an innovative optimized feedback power control strategy, which tries to make the network operational point fall in the feasible SNR region at the lowest overall transmit energy consumption. These strategies will be referred to as “balanced SNR” and “unbalanced SNR,” respectively. While they require, in principle, an unlimited power control range at the sources, we also propose practical versions with a limited power control range. We preliminary consider a scenario with orthogonal links and ideal feedback. Then, we analyze the robustness of the proposed power control strategies to possible non-idealities, in terms of residual multiple access interference and noisy feedback channels. Finally, we successfully apply the proposed feedback power control strategies to a limiting case of the class of considered multiple access schemes, namely a central estimating officer (CEO) scenario, where the sensors observe noisy versions of a common binary information sequence and the AP's goal is to estimate this sequence by properly fusing the soft-output information output by the JCD algorithm. PMID:22291536

Fourth Annual International Acquisitions Workshop: Access to Multiple Media Worldwide

NASA Technical Reports Server (NTRS)

1994-01-01

Topics discussed during the workshop include: (1) Multinational-Multiple media collections and activities spanning many countries; (2) Multiple media in North American trade and commerce; (3) African spotlight; (4) Europe-Multiple media in national libraries and services; (5) Scandinavian spotlight; (6) Internet update; (7) Multiple media in US federal agencies; (8) Open-source multiple media in US federal agencies; and (9) Multiple media at US federal technical agencies-NIST and NOAA.

Evaluation of Renal Function after Percutaneous Nephrolithotomy-Does the Number of Percutaneous Access Tracts Matter?

PubMed

Gorbachinsky, Ilya; Wood, Kyle; Colaco, Marc; Hemal, Sij; Mettu, Jayadev; Mirzazadeh, Majid; Assimos, Dean G; Gutierrez-Aćeves, Jorge

2016-07-01

Renal function following percutaneous nephrolithotomy has long been a concern to urologists, especially in the setting of multi-tract access. We determined whether the risk of renal injury after multi-tract percutaneous nephrolithotomy was greater than after a single access approach. We retrospectively reviewed the records of 307 consecutive patients treated with percutaneous nephrolithotomy from 2011 to 2012 at Wake Forest Health. Perioperative (99m)Tc-mercaptoacetyltriglycine nuclear renogram parameters along with serum creatinine values were assessed within 1 year of the procedure. Patients were stratified by single access vs multi-access (2 or more). We identified 110 cases in which renography was done before and after percutaneous nephrolithotomy. A total of 74 patients (67.3%) underwent single access percutaneous nephrolithotomy while 36 (32.7%) underwent multi-access percutaneous nephrolithotomy. Serum creatinine did not significantly differ between the 2 cohorts postoperatively (p = 0.09). There was a significant 2.28% decrease in renal function based on mercaptoacetyltriglycine nuclear renogram results after percutaneous nephrolithotomy of the affected kidney in patients with multiple accesses (p <0.01). This relationship was not observed when patients were stratified by multiple comorbidities associated with nephrolithiasis. Multi-access percutaneous nephrolithotomy is associated with a small reduction in the function of the targeted kidney compared to a single access approach. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Securely and Flexibly Sharing a Biomedical Data Management System

PubMed Central

Wang, Fusheng; Hussels, Phillip; Liu, Peiya

2011-01-01

Biomedical database systems need not only to address the issues of managing complex data, but also to provide data security and access control to the system. These include not only system level security, but also instance level access control such as access of documents, schemas, or aggregation of information. The latter is becoming more important as multiple users can share a single scientific data management system to conduct their research, while data have to be protected before they are published or IP-protected. This problem is challenging as users’ needs for data security vary dramatically from one application to another, in terms of who to share with, what resources to be shared, and at what access level. We develop a comprehensive data access framework for a biomedical data management system SciPort. SciPort provides fine-grained multi-level space based access control of resources at not only object level (documents and schemas), but also space level (resources set aggregated in a hierarchy way). Furthermore, to simplify the management of users and privileges, customizable role-based user model is developed. The access control is implemented efficiently by integrating access privileges into the backend XML database, thus efficient queries are supported. The secure access approach we take makes it possible for multiple users to share the same biomedical data management system with flexible access management and high data security. PMID:21625285

Bias analysis applied to Agricultural Health Study publications to estimate non-random sources of uncertainty.

PubMed

Lash, Timothy L

2007-11-26

The associations of pesticide exposure with disease outcomes are estimated without the benefit of a randomized design. For this reason and others, these studies are susceptible to systematic errors. I analyzed studies of the associations between alachlor and glyphosate exposure and cancer incidence, both derived from the Agricultural Health Study cohort, to quantify the bias and uncertainty potentially attributable to systematic error. For each study, I identified the prominent result and important sources of systematic error that might affect it. I assigned probability distributions to the bias parameters that allow quantification of the bias, drew a value at random from each assigned distribution, and calculated the estimate of effect adjusted for the biases. By repeating the draw and adjustment process over multiple iterations, I generated a frequency distribution of adjusted results, from which I obtained a point estimate and simulation interval. These methods were applied without access to the primary record-level dataset. The conventional estimates of effect associating alachlor and glyphosate exposure with cancer incidence were likely biased away from the null and understated the uncertainty by quantifying only random error. For example, the conventional p-value for a test of trend in the alachlor study equaled 0.02, whereas fewer than 20% of the bias analysis iterations yielded a p-value of 0.02 or lower. Similarly, the conventional fully-adjusted result associating glyphosate exposure with multiple myleoma equaled 2.6 with 95% confidence interval of 0.7 to 9.4. The frequency distribution generated by the bias analysis yielded a median hazard ratio equal to 1.5 with 95% simulation interval of 0.4 to 8.9, which was 66% wider than the conventional interval. Bias analysis provides a more complete picture of true uncertainty than conventional frequentist statistical analysis accompanied by a qualitative description of study limitations. The latter approach is likely to lead to overconfidence regarding the potential for causal associations, whereas the former safeguards against such overinterpretations. Furthermore, such analyses, once programmed, allow rapid implementation of alternative assignments of probability distributions to the bias parameters, so elevate the plane of discussion regarding study bias from characterizing studies as "valid" or "invalid" to a critical and quantitative discussion of sources of uncertainty.

Evolutionary-Optimized Photonic Network Structure in White Beetle Wing Scales.

PubMed

Wilts, Bodo D; Sheng, Xiaoyuan; Holler, Mirko; Diaz, Ana; Guizar-Sicairos, Manuel; Raabe, Jörg; Hoppe, Robert; Liu, Shu-Hao; Langford, Richard; Onelli, Olimpia D; Chen, Duyu; Torquato, Salvatore; Steiner, Ullrich; Schroer, Christian G; Vignolini, Silvia; Sepe, Alessandro

2018-05-01

Most studies of structural color in nature concern periodic arrays, which through the interference of light create color. The "color" white however relies on the multiple scattering of light within a randomly structured medium, which randomizes the direction and phase of incident light. Opaque white materials therefore must be much thicker than periodic structures. It is known that flying insects create "white" in extremely thin layers. This raises the question, whether evolution has optimized the wing scale morphology for white reflection at a minimum material use. This hypothesis is difficult to prove, since this requires the detailed knowledge of the scattering morphology combined with a suitable theoretical model. Here, a cryoptychographic X-ray tomography method is employed to obtain a full 3D structural dataset of the network morphology within a white beetle wing scale. By digitally manipulating this 3D representation, this study demonstrates that this morphology indeed provides the highest white retroreflection at the minimum use of material, and hence weight for the organism. Changing any of the network parameters (within the parameter space accessible by biological materials) either increases the weight, increases the thickness, or reduces reflectivity, providing clear evidence for the evolutionary optimization of this morphology. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Accessing and visualizing scientific spatiotemporal data

NASA Technical Reports Server (NTRS)

Katz, Daniel S.; Bergou, Attila; Berriman, G. Bruce; Block, Gary L.; Collier, Jim; Curkendall, David W.; Good, John; Husman, Laura; Jacob, Joseph C.; Laity, Anastasia;

Broadband Time Division Multiple Access (TDMA) Solution (Tech Insertion - C4 Enhancement for the U.S. Army in Transformation)

DTIC Science & Technology

2005-06-01

synchronization , timing and frequency to all of the traffic terminals through the reference burst. The MRT also periodically synchronizes all of the traffic...1 2005 Command and Control Research and Technology Symposium The Future of C2 Broadband Time Division Multiple Access (TDMA) Solution...UK Army) Dale White Barry Kruse Shawn White LTC Edward Eidson Thomas Mims COL Charles Dunn III Charlie Pangle Battle Command Battle

Combining data from multiple sources using the CUAHSI Hydrologic Information System

NASA Astrophysics Data System (ADS)

Tarboton, D. G.; Ames, D. P.; Horsburgh, J. S.; Goodall, J. L.

2012-12-01

The Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) has developed a Hydrologic Information System (HIS) to provide better access to data by enabling the publication, cataloging, discovery, retrieval, and analysis of hydrologic data using web services. The CUAHSI HIS is an Internet based system comprised of hydrologic databases and servers connected through web services as well as software for data publication, discovery and access. The HIS metadata catalog lists close to 100 web services registered to provide data through this system, ranging from large federal agency data sets to experimental watersheds managed by University investigators. The system's flexibility in storing and enabling public access to similarly formatted data and metadata has created a community data resource from governmental and academic data that might otherwise remain private or analyzed only in isolation. Comprehensive understanding of hydrology requires integration of this information from multiple sources. HydroDesktop is the client application developed as part of HIS to support data discovery and access through this system. HydroDesktop is founded on an open source GIS client and has a plug-in architecture that has enabled the integration of modeling and analysis capability with the functionality for data discovery and access. Model integration is possible through a plug-in built on the OpenMI standard and data visualization and analysis is supported by an R plug-in. This presentation will demonstrate HydroDesktop, showing how it provides an analysis environment within which data from multiple sources can be discovered, accessed and integrated.

Latin American algorithm for treatment of relapsing-remitting multiple sclerosis using disease-modifying agents.

PubMed

Finkelsztejn, Alessandro; Gabbai, Alberto Alain; Fragoso, Yara Dadalti; Carrá, Adriana; Macías-Islas, Miguel Angel; Arcega-Revilla, Raul; García-Bonitto, Juan; Oehninger-Gatti, Carlos Luis; Orozco-Escobar, Geraldine; Tarulla, Adriana; Vergara, Fernando; Vizcarra, Darwin

2012-10-01

It is estimated that circa 50,000 individuals have relapsing-remitting multiple sclerosis in Latin America. European and North-American algorithms for the treatment of multiple sclerosis do not foresee our regional difficulties and the access of patients to treatment. The Latin American Multiple Sclerosis Forum is an independent and supra-institutional group of experts that has assessed the latest scientific evidence regarding efficacy and safety of disease-modifying treatments. Accesses to treatment and pharmacovigilance programs for each of the eight countries represented at the Forum were also analyzed. A specific set of guidelines based upon evidence-based recommendations was designed for Latin America. Future perspectives of multiple sclerosis treatment were also discussed. The present paper translated an effort from representatives of eight countries discussing a matter that cannot be adapted to our region directly from purely European and North-American guidelines for treatment.

Virtual Computing Laboratories: A Case Study with Comparisons to Physical Computing Laboratories

ERIC Educational Resources Information Center

Burd, Stephen D.; Seazzu, Alessandro F.; Conway, Christopher

2009-01-01

Current technology enables schools to provide remote or virtual computing labs that can be implemented in multiple ways ranging from remote access to banks of dedicated workstations to sophisticated access to large-scale servers hosting virtualized workstations. This paper reports on the implementation of a specific lab using remote access to…

The introduction and evaluation of mobile devices to improve access to patient records: a catalyst for innovation and collaboration at BCCA.

PubMed

Wu, Jonn; Waldron, John; Hood, Shaina; Kahnamelli, Adam; Khan, Mohamed; Barnett, Jeff; French, John; Slager, Stacey; Melhem, Shadi; Shabestari, Omid

2013-01-01

Prompt and efficient access to patient records is vital in providing optimal patient care. The Cancer Agency Information System (CAIS) is the primary patient record repository for the British Columbia Cancer Agency (BCCA) but is only accessible on traditional computer workstations. The BCCA clinics have significant space limitations resulting in multiple health care professionals sharing each workstation. Furthermore, workstations are not available in examination rooms. A novel and cost efficient solution is necessary to improve clinician access to CAIS. This prompted the BCCA and IMITS to embark on an innovative provincial collaboration to introduce and evaluate the impact of a mobile device to improve access to CAIS. The project consisted of 2 phases with over 50 participants from multiple clinical disciplines across BCCA sites. Phase I evaluated the adoptability, effectiveness and costs associated with providing access to CAIS using a generic viewer (Citrix). Phase II incorporated the feedback and findings from Phase I to make available a customized mobile device-specific application. Phase II also addressed privacy and security requirements.

Unexpected surface implanted layer in static random access memory devices observed by microwave impedance microscope

NASA Astrophysics Data System (ADS)

Kundhikanjana, W.; Yang, Y.; Tanga, Q.; Zhang, K.; Lai, K.; Ma, Y.; Kelly, M. A.; Li, X. X.; Shen, Z.-X.

2013-02-01

Real-space mapping of doping concentration in semiconductor devices is of great importance for the microelectronics industry. In this work, a scanning microwave impedance microscope (MIM) is employed to resolve the local conductivity distribution of a static random access memory sample. The MIM electronics can also be adjusted to the scanning capacitance microscopy (SCM) mode, allowing both measurements on the same region. Interestingly, while the conventional SCM images match the nominal device structure, the MIM results display certain unexpected features, which originate from a thin layer of the dopant ions penetrating through the protective layers during the heavy implantation steps.

Development of highly reliable static random access memory for 40-nm embedded split gate-MONOS flash memory

NASA Astrophysics Data System (ADS)

Okamoto, Shin-ichi; Maekawa, Kei-ichi; Kawashima, Yoshiyuki; Shiba, Kazutoshi; Sugiyama, Hideki; Inoue, Masao; Nishida, Akio

2015-04-01

High quality static random access memory (SRAM) for 40-nm embedded MONOS flash memory with split gate (SG-MONOS) was developed. Marginal failure, which results in threshold voltage/drain current tailing and outliers of SRAM transistors, occurs when using a conventional SRAM structure. These phenomena can be explained by not only gate depletion but also partial depletion and percolation path formation in the MOS channel. A stacked poly-Si gate structure can suppress these phenomena and achieve high quality SRAM without any defects in the 6σ level and with high affinity to the 40-nm SG-MONOS process was developed.

Integrated, nonvolatile, high-speed analog random access memory

NASA Technical Reports Server (NTRS)

Katti, Romney R. (Inventor); Wu, Jiin-Chuan (Inventor); Stadler, Henry L. (Inventor)

1994-01-01

This invention provides an integrated, non-volatile, high-speed random access memory. A magnetically switchable ferromagnetic or ferrimagnetic layer is sandwiched between an electrical conductor which provides the ability to magnetize the magnetically switchable layer and a magneto resistive or Hall effect material which allows sensing the magnetic field which emanates from the magnetization of the magnetically switchable layer. By using this integrated three-layer form, the writing process, which is controlled by the conductor, is separated from the storage medium in the magnetic layer and from the readback process which is controlled by the magnetoresistive layer. A circuit for implementing the memory in CMOS or the like is disclosed.

A stochastic simulation method for the assessment of resistive random access memory retention reliability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berco, Dan, E-mail: danny.barkan@gmail.com; Tseng, Tseung-Yuen, E-mail: tseng@cc.nctu.edu.tw

This study presents an evaluation method for resistive random access memory retention reliability based on the Metropolis Monte Carlo algorithm and Gibbs free energy. The method, which does not rely on a time evolution, provides an extremely efficient way to compare the relative retention properties of metal-insulator-metal structures. It requires a small number of iterations and may be used for statistical analysis. The presented approach is used to compare the relative robustness of a single layer ZrO{sub 2} device with a double layer ZnO/ZrO{sub 2} one, and obtain results which are in good agreement with experimental data.

Optical memory development. Volume 2: Gain-assisted holographic storage media

NASA Technical Reports Server (NTRS)

Gange, R. A.; Mezrich, R. S.

1972-01-01

Thin deformable films were investigated for use as the storage medium in a holographic optical memory. The research was directed toward solving the problems of material fatigue, selective heat addressing, electrical charging of the film surface and charge patterning by light. A number of solutions to these problems were found but the main conclusion to be drawn from the work is that deformable media which employ heat in the recording process are not satisfactory for use in a high-speed random-access read/write holographic memory. They are, however, a viable approach in applications where either high speed or random-access is not required.

Research on a Queue Scheduling Algorithm in Wireless Communications Network

NASA Astrophysics Data System (ADS)

Yang, Wenchuan; Hu, Yuanmei; Zhou, Qiancai

This paper proposes a protocol QS-CT, Queue Scheduling Mechanism based on Multiple Access in Ad hoc net work, which adds queue scheduling mechanism to RTS-CTS-DATA using multiple access protocol. By endowing different queues different scheduling mechanisms, it makes networks access to the channel much more fairly and effectively, and greatly enhances the performance. In order to observe the final performance of the network with QS-CT protocol, we simulate it and compare it with MACA/C-T without QS-CT protocol. Contrast to MACA/C-T, the simulation result shows that QS-CT has greatly improved the throughput, delay, rate of packets' loss and other key indicators.

Performance evaluation of modulation and multiple access schemes in ultraviolet optical wireless connections for two atmosphere thickness cases.

PubMed

Raptis, Nikos; Pikasis, Evangelos; Syvridis, Dimitris

2016-08-01

The exploitation of optical wireless communication channels in a non-line-of-sight regime is studied for point-to-point and networking configurations considering the use of light-emitting diodes. Two environments with different scattering center densities are considered, assuming operation at 265 nm. The bit error rate performance of both pulsed and multicarrier modulation schemes is examined, using numerical approaches. In the networking scenario, a central node only receives data, one node transmits useful data, and the rest of them act as interferers. The performance of the desirable node's transmissions is evaluated. The access to the medium is controlled by a code division multiple access scheme.

Apollo: Giving application developers a single point of access to public health models using structured vocabularies and Web services

PubMed Central

Wagner, Michael M.; Levander, John D.; Brown, Shawn; Hogan, William R.; Millett, Nicholas; Hanna, Josh

2013-01-01

This paper describes the Apollo Web Services and Apollo-SV, its related ontology. The Apollo Web Services give an end-user application a single point of access to multiple epidemic simulators. An end user can specify an analytic problem—which we define as a configuration and a query of results—exactly once and submit it to multiple epidemic simulators. The end user represents the analytic problem using a standard syntax and vocabulary, not the native languages of the simulators. We have demonstrated the feasibility of this design by implementing a set of Apollo services that provide access to two epidemic simulators and two visualizer services. PMID:24551417

Apollo: giving application developers a single point of access to public health models using structured vocabularies and Web services.

PubMed

Wagner, Michael M; Levander, John D; Brown, Shawn; Hogan, William R; Millett, Nicholas; Hanna, Josh

2013-01-01

This paper describes the Apollo Web Services and Apollo-SV, its related ontology. The Apollo Web Services give an end-user application a single point of access to multiple epidemic simulators. An end user can specify an analytic problem-which we define as a configuration and a query of results-exactly once and submit it to multiple epidemic simulators. The end user represents the analytic problem using a standard syntax and vocabulary, not the native languages of the simulators. We have demonstrated the feasibility of this design by implementing a set of Apollo services that provide access to two epidemic simulators and two visualizer services.

A simple, effective media access protocol system for integrated, high data rate networks

NASA Technical Reports Server (NTRS)

Foudriat, E. C.; Maly, K.; Overstreet, C. M.; Khanna, S.; Zhang, L.

1992-01-01

The operation and performance of a dual media access protocol for integrated, gigabit networks are described. Unlike other dual protocols, each protocol supports a different class of traffic. The Carrier Sensed Multiple Access-Ring Network (CSMA/RN) protocol and the Circulating Reservation Packet (CRP) protocol support asynchronous and synchronous traffic, respectively. The two protocols operate with minimal impact upon each other. Performance information demonstrates that they support a complete range of integrated traffic loads, do not require call setup/termination or a special node for synchronous traffic control, and provide effective pre-use and recovery. The CRP also provides guaranteed access and fairness control for the asynchronous system. The paper demonstrates that the CSMA-CRP system fulfills many of the requirements for gigabit LAN-MAN networks most effectively and simply. To accomplish this, CSMA-CRP features are compared against similar ring and bus systems, such as Cambridge Fast Ring, Metaring, Cyclic Reservation Multiple Access, and Distributed Dual Queue Data Bus (DQDB).

Efficacy and safety profile of memantine in patients with cognitive impairment in multiple sclerosis: A randomized, placebo-controlled study.

PubMed

Peyro Saint Paul, Laure; Creveuil, Christian; Heinzlef, Olivier; De Seze, Jerome; Vermersch, Patrick; Castelnovo, Giovanni; Cabre, Philippe; Debouverie, Marc; Brochet, Bruno; Dupuy, Benoit; Lebiez, Pierre; Sartori, Éric; Clavelou, Pierre; Brassat, David; Lebrun-Frenay, Christine; Daplaud, David; Pelletier, Jean; Coman, Irène; Hautecoeur, Patrick; Tourbah, Ayman; Defer, Gilles

2016-04-15

Memantine, an uncompetitive antagonist of N-methyl-D-aspartate (NMDA)-type glutamate receptors that was approved for the treatment of moderate to severe Alzheimer's disease, has been negatively evaluated for the treatment of cognitive disorders of multiple sclerosis, but these studies were conducted only during short-term administration and on a heterogeneous group of patients with different forms of the disease. In addition, many adverse reactions were observed in these patients. The purpose of the "EMERITE" (NCT01074619) study was to examine the efficacy and safety of the long-term administration of memantine as a symptomatic treatment for cognitive disorders in patients with relapsing-remitting multiple sclerosis (RR-MS). The study was supported by the French Ministry of Health and received additional support from Lundbeck. In this double-blind, placebo-controlled, parallel group, randomized trial, the participants were assigned to receive memantine (20 mg/day) or a placebo for 52 weeks. The participants included males and females, 18-60 years of age, with a diagnosis of RR-MS and presenting with a cognitive complaint and/or demonstrating moderate cognitive impairment. The data were collected in the Department of Neurology in 19 French centers. The primary outcome was the Paced Auditory Serial Addition Test (PASAT) score at week 52. Secondary measurements included additional neuropsychological tests and the annualized relapse rate. The scores were adjusted according to the baseline scores in the analysis. The safety was assessed by the number of adverse events. The random sequence was generated using the Excel software. At each center, only the pharmacist had access to the allocation sequence and could be asked to unblind the trial. Fifty patients were allocated to the memantine group, and 43 to the placebo group. The intent-to-treat (ITT) population included 31 patients in each group. After adjusting for the PASAT scores at baseline, the PASAT scores at the end point did not differ between the memantine and the placebo groups (p=0.88). Adjusted mean score difference (memantine minus placebo), was -0.40 (95% confidence interval: -5.5; +4.7). No significant differences were observed for the secondary outcomes (short term memory and attention scores, EDSS, and relapse rate). The findings remained unchanged after multiple imputation of the missing values. Neurological and psychiatric adverse events were significantly higher in the memantine group than in the placebo group, and these parameters were higher than those reported in the product literature of memantine. No differences between the placebo and memantine groups were observed. Nevertheless, the tolerability of memantine was significantly worse than expected. Copyright © 2016 Elsevier B.V. All rights reserved.

CINAHL and MEDLINE: a comparison of indexing practices.

PubMed

Brenner, S H; McKinin, E J

1989-10-01

A random sample of fifty nursing articles indexed in both MEDLINE and CINAHL (NURSING & ALLIED HEALTH) during 1986 was used for comparing indexing practices. Indexing was analyzed by counting the number of major descriptors, the number of major and minor descriptors, the number of indexing access points, the number of common indexing access points, and the number and type of unique indexing access points. The study results indicate: there are few differences in the number of major descriptors used, MEDLINE uses almost twice as many descriptors, MEDLINE has almost twice as many indexing access points, and MEDLINE and CINAHL provide few common access points.

CINAHL and MEDLINE: a comparison of indexing practices.

PubMed Central

Brenner, S H; McKinin, E J

1989-01-01

A random sample of fifty nursing articles indexed in both MEDLINE and CINAHL (NURSING & ALLIED HEALTH) during 1986 was used for comparing indexing practices. Indexing was analyzed by counting the number of major descriptors, the number of major and minor descriptors, the number of indexing access points, the number of common indexing access points, and the number and type of unique indexing access points. The study results indicate: there are few differences in the number of major descriptors used, MEDLINE uses almost twice as many descriptors, MEDLINE has almost twice as many indexing access points, and MEDLINE and CINAHL provide few common access points. PMID:2676049

Effects of absorption on multiple scattering by random particulate media: exact results.

PubMed

Mishchenko, Michael I; Liu, Li; Hovenier, Joop W

2007-10-01

We employ the numerically exact superposition T-matrix method to perform extensive computations of elec nottromagnetic scattering by a volume of discrete random medium densely filled with increasingly absorbing as well as non-absorbing particles. Our numerical data demonstrate that increasing absorption diminishes and nearly extinguishes certain optical effects such as depolarization and coherent backscattering and increases the angular width of coherent backscattering patterns. This result corroborates the multiple-scattering origin of such effects and further demonstrates the heuristic value of the concept of multiple scattering even in application to densely packed particulate media.

Interest in Providing Multiple Sclerosis Care and Subspecializing in Multiple Sclerosis Among Neurology Residents

PubMed Central

Teixeira-Poit, Stephanie; Kane, Heather L.; Frost, A. Corey; Keating, Michael; Olmsted, Murrey

2014-01-01

Background: Although detailed knowledge regarding treatment options for multiple sclerosis (MS) patients is largely limited to neurologists, shortages in the neurologist workforce, including MS subspecialists, are predicted. Thus, MS patients may have difficulties in gaining access to appropriate care. No systematic evaluation has yet been performed of the number of neurology residents planning to pursue MS subspecialization. This study identifies factors affecting interest in providing MS patient care or MS subspecialization among current neurology residents. Methods: We randomly selected half of all Accreditation Council of Graduate Medical Education–certified neurology residency programs in the continental United States to receive the neurology resident survey. Completed surveys were received from 218 residents. Results: Residents were significantly more likely to have increased interest in MS care when they participated in MS research, were interested in teaching, and indicated that the “ability to improve patient outcomes and quality of life” was a positive factor influencing their desire to provide MS patient care. Residents who were interested in providing MS care, interested in teaching, and indicated that “research opportunities” was a positive factor for providing MS patient care were significantly more likely to express interest in MS subspecialization. Conclusions: Increasing opportunities to interact with MS patients, learn about MS care, and participate in MS research may increase interest in MS care and subspecialization among neurology residents. Opportunities to educate residents regarding MS patient care may affect residents’ attitudes. PMID:24688352

Stand-alone scattering optical device using holographic photopolymer (Conference Presentation)

NASA Astrophysics Data System (ADS)

Park, Jongchan; Lee, KyeoReh; Park, YongKeun

2016-03-01

When a light propagates through highly disordered medium, its optical parameters such as amplitude, phase and polarization states are completely scrambled because of multiple scattering events. Since the multiple scattering is a fundamental optical process that contains extremely high degrees of freedom, optical information of a transmitted light is totally mingled. Until recently, the presence of multiple scattering in an inhomogeneous medium is considered as a major obstacle when manipulating a light transmitting through the medium. However, a recent development of wavefront shaping techniques enable us to control the propagation of light through turbid media; a light transmitting through a turbid medium can be effectively controlled by modulating the spatial profile of the incident light using spatial light modulator. In this work, stand-alone scattering optical device is proposed; a holographic photopolymer film, which is much economic compared to the other digital spatial light modulators, is used to record and reconstruct permanent wavefront to generate optical field behind a scattering medium. By employing our method, arbitrary optical field can be generated since the scattering medium completely mixes all the optical parameters which allow us to access all the optical information only by modulating spatial phase profile of the impinging wavefront. The method is experimentally demonstrated in both the far-field and near-field regime where it shows promising fidelity and stability. The proposed stand-alone scattering optical device will opens up new avenues for exploiting the randomness inherent in disordered medium.

Web service activities at the IRIS DMC to support federated and multidisciplinary access

NASA Astrophysics Data System (ADS)

Trabant, Chad; Ahern, Timothy K.

2013-04-01

At the IRIS Data Management Center (DMC) we have developed a suite of web service interfaces to access our large archive of, primarily seismological, time series data and related metadata. The goals of these web services include providing: a) next-generation and easily used access interfaces for our current users, b) access to data holdings in a form usable for non-seismologists, c) programmatic access to facilitate integration into data processing workflows and d) a foundation for participation in federated data discovery and access systems. To support our current users, our services provide access to the raw time series data and metadata or conversions of the raw data to commonly used formats. Our services also support simple, on-the-fly signal processing options that are common first steps in many workflows. Additionally, high-level data products derived from raw data are available via service interfaces. To support data access by researchers unfamiliar with seismic data we offer conversion of the data to broadly usable formats (e.g. ASCII text) and data processing to convert the data to Earth units. By their very nature, web services are programmatic interfaces. Combined with ubiquitous support for web technologies in programming & scripting languages and support in many computing environments, web services are very well suited for integrating data access into data processing workflows. As programmatic interfaces that can return data in both discipline-specific and broadly usable formats, our services are also well suited for participation in federated and brokered systems either specific to seismology or multidisciplinary. Working within the International Federation of Digital Seismograph Networks, the DMC collaborated on the specification of standardized web service interfaces for use at any seismological data center. These data access interfaces, when supported by multiple data centers, will form a foundation on which to build discovery and access mechanisms for data sets spanning multiple centers. To promote the adoption of these standardized services the DMC has developed portable implementations of the software needed to host these interfaces, minimizing the work required at each data center. Within the COOPEUS project framework, the DMC is working with EU partners to install web services implementations at multiple data centers in Europe.

Network accessibility & the evoluation of urban employment.

DOT National Transportation Integrated Search

2011-06-01

This research examines the impact of accessibility on the growth of employment centers in the : Los Angeles Region between 1980 and 2000. There is extensive empirical documentation of : polycentricity the presence of multiple concentrations of em...

Random access to mobile networks with advanced error correction

NASA Technical Reports Server (NTRS)

Dippold, Michael

1990-01-01

A random access scheme for unreliable data channels is investigated in conjunction with an adaptive Hybrid-II Automatic Repeat Request (ARQ) scheme using Rate Compatible Punctured Codes (RCPC) Forward Error Correction (FEC). A simple scheme with fixed frame length and equal slot sizes is chosen and reservation is implicit by the first packet transmitted randomly in a free slot, similar to Reservation Aloha. This allows the further transmission of redundancy if the last decoding attempt failed. Results show that a high channel utilization and superior throughput can be achieved with this scheme that shows a quite low implementation complexity. For the example of an interleaved Rayleigh channel and soft decision utilization and mean delay are calculated. A utilization of 40 percent may be achieved for a frame with the number of slots being equal to half the station number under high traffic load. The effects of feedback channel errors and some countermeasures are discussed.

Multi-component access to a community-based weight loss program: 12 week results

USDA-ARS?s Scientific Manuscript database

The current study examined weight loss between a comprehensive lifestyle modification program (Weight Watchers PointsPlus program) that included three ways to access and a self-help (SH) condition. A total of 293 participants were randomized to either a Weight Watchers condition (WW) (n=148) or a SH...

Unsupervised Metric Fusion Over Multiview Data by Graph Random Walk-Based Cross-View Diffusion.

PubMed

Wang, Yang; Zhang, Wenjie; Wu, Lin; Lin, Xuemin; Zhao, Xiang

2017-01-01

Learning an ideal metric is crucial to many tasks in computer vision. Diverse feature representations may combat this problem from different aspects; as visual data objects described by multiple features can be decomposed into multiple views, thus often provide complementary information. In this paper, we propose a cross-view fusion algorithm that leads to a similarity metric for multiview data by systematically fusing multiple similarity measures. Unlike existing paradigms, we focus on learning distance measure by exploiting a graph structure of data samples, where an input similarity matrix can be improved through a propagation of graph random walk. In particular, we construct multiple graphs with each one corresponding to an individual view, and a cross-view fusion approach based on graph random walk is presented to derive an optimal distance measure by fusing multiple metrics. Our method is scalable to a large amount of data by enforcing sparsity through an anchor graph representation. To adaptively control the effects of different views, we dynamically learn view-specific coefficients, which are leveraged into graph random walk to balance multiviews. However, such a strategy may lead to an over-smooth similarity metric where affinities between dissimilar samples may be enlarged by excessively conducting cross-view fusion. Thus, we figure out a heuristic approach to controlling the iteration number in the fusion process in order to avoid over smoothness. Extensive experiments conducted on real-world data sets validate the effectiveness and efficiency of our approach.

Human placenta-derived cells (PDA-001) for the treatment of adults with multiple sclerosis: a randomized, placebo-controlled, multiple-dose study.

PubMed

Lublin, Fred D; Bowen, James D; Huddlestone, John; Kremenchutzky, Marcelo; Carpenter, Adam; Corboy, John R; Freedman, Mark S; Krupp, Lauren; Paulo, Corri; Hariri, Robert J; Fischkoff, Steven A

2014-11-01

Infusion of PDA-001, a preparation of mesenchymal-like cells derived from full-term human placenta, is a new approach in the treatment of patients with multiple sclerosis. This safety study aimed to rule out the possibility of paradoxical exacerbation of disease activity by PDA-001 in patients with multiple sclerosis. This was a phase 1b, multicenter, randomized, double-blind, placebo-controlled, 2-dose ranging study including patients with relapsing-remitting multiple sclerosis or secondary progressive multiple sclerosis. The study was conducted at 6 sites in the United States and 2 sites in Canada. Patients were randomized 3:1 to receive 2 low-dose infusions of PDA-001 (150×10(6) cells) or placebo, given 1 week apart. After completing this cohort, subsequent patients received high-dose PDA-001 (600×10(6) cells) or placebo. Monthly brain magnetic resonance imaging scans were performed. The primary end point was ruling out the possibility of paradoxical worsening of MS disease activity. This was monitored using Cutter׳s rule (≥5 new gadolinium lesions on 2 consecutive scans) by brain magnetic resonance imaging on a monthly basis for six months and also the frequency of multiple sclerosis relapse. Ten patients with relapsing-remitting multiple sclerosis and 6 with secondary progressive multiple sclerosis were randomly assigned to treatment: 6 to low-dose PDA-001, 6 to high-dose PDA-001, and 4 to placebo. No patient met Cutter׳s rule. One patient receiving high-dose PDA-001 had an increase in T2 and gadolinium lesions and in Expanded Disability Status Scale score during a multiple sclerosis flare 5 months after receiving PDA-001. No other patient had an increase in Expanded Disability Status Scale score>0.5, and most had stable or decreasing Expanded Disability Status Scale scores. With high-dose PDA-001, 1 patient experienced a grade 1 anaphylactoid reaction and 1 had grade 2 superficial thrombophlebitis. Other adverse events were mild to moderate and included headache, fatigue, infusion site reactions, and urinary tract infection. PDA-001 infusions were safe and well tolerated in relapsing-remitting multiple sclerosis and secondary progressive multiple sclerosis patients. No paradoxical worsening of lesion counts was noted with either dose. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Assessments of the quality of randomized controlled trials published in International Journal of Urology from 1994 to 2011.

PubMed

Cho, Hee Ju; Chung, Jae Hoon; Jo, Jung Ki; Kang, Dong Hyuk; Cho, Jeong Man; Yoo, Tag Keun; Lee, Seung Wook

2013-12-01

Randomized controlled trials are one of the most reliable resources for assessing the effectiveness and safety of medical treatments. Low quality randomized controlled trials carry a large bias that can ultimately impair the reliability of their conclusions. The present study aimed to evaluate the quality of randomized controlled trials published in International Journal of Urology by using multiple quality assessment tools. Randomized controlled trials articles published in International Journal of Urology were found using the PubMed MEDLINE database, and qualitative analysis was carried out with three distinct assessment tools: the Jadad scale, the van Tulder scale and the Cochrane Collaboration Risk of Bias Tool. The quality of randomized controlled trials was analyzed by publication year, type of subjects, intervention, presence of funding and whether an institutional review board reviewed the study. A total of 68 randomized controlled trial articles were published among a total of 1399 original articles in International Journal of Urology. Among these randomized controlled trials, 10 (2.70%) were from 1994 to 1999, 23 (4.10%) were from 2000 to 2005 and 35 (4.00%) were from 2006 to 2011 (P = 0.494). On the assessment with the Jadad and van Tulder scale, the numbers and percentage of high quality randomized controlled trials increased over time. The studies that had institutional review board reviews, funding resources or that were carried out in multiple institutions had an increased percentage of high quality articles. The numbers and percentage of high-quality randomized controlled trials published in International Journal of Urology have increased over time. Furthermore, randomized controlled trials with funding resources, institutional review board reviews or carried out in multiple institutions have been found to be of higher quality compared with others not presenting these features. © 2013 The Japanese Urological Association.

A descriptive study of access to services in a random sample of Canadian rural emergency departments

PubMed Central

Fleet, Richard; Poitras, Julien; Maltais-Giguère, Julie; Villa, Julie; Archambault, Patrick

2013-01-01

Objective To examine 24/7 access to services and consultants in a sample of Canadian rural emergency departments (EDs). Design Cross-sectional study—mixed methods (structured interview, survey and government data bases) with random sampling of hospitals. Setting Canadian rural EDs (rural small town (RST) definition—Statistics Canada). Participants 28% (95/336) of Canadian rural EDs providing 24/7 physician coverage located in hospitals with acute care hospitalisation beds. Main outcome measures General characteristics of the rural EDs, information about 24/7 access to consultants, equipment and services, and the proportion of rural hospitals more than 300 km from levels 1 and 2 trauma centres. Results Of the 336 rural EDs identified, 122 (36%) were randomly selected and contacted. Overall, 95 EDs participated in the study (participation rate, 78%). Hospitals had, on an average, 23 acute care beds, 7 ED stretchers and 13 500 annual ED visits. The proportion of rural hospitals with local access to the following 24/7 services was paediatrician, 5%; obstetrician, 10%; psychiatrist, 11%; internist, 12%; intensive care unit, 17%; CT scanner, 20%; surgeon, 26%; ultrasound, 28%; basic X-ray, 97% and laboratory services, 99%. Forty-four per cent and 54% of the RST EDs were more than 300 km from a level 1 and level 2 trauma centre, respectively. Conclusions This is the first study describing the services available in Canadian rural EDs. Apart from basic laboratory and X-ray services, most rural EDs have limited access to consultants, advanced imaging and critical care services. A detailed study is needed to evaluate the impact of these limited services on patient outcomes, costs and interfacility transport demands. PMID:24285633

A physical layer perspective on access network sharing

NASA Astrophysics Data System (ADS)

Pfeiffer, Thomas

2015-12-01

Unlike in copper or wireless networks, there is no sharing of resources in fiber access networks yet, other than bit stream access or cable sharing, in which the fibers of a cable are let to one or multiple operators. Sharing optical resources on a single fiber among multiple operators or different services has not yet been applied. While this would allow for a better exploitation of installed infrastructures, there are operational issues which still need to be resolved, before this sharing model can be implemented in networks. Operating multiple optical systems and services over a common fiber plant, autonomously and independently from each other, can result in mutual distortions on the physical layer. These distortions will degrade the performance of the involved systems, unless precautions are taken in the infrastructure hardware to eliminate or to reduce them to an acceptable level. Moreover, the infrastructure needs to be designed such as to support different system technologies and to ensure a guaranteed quality of the end-to-end connections. In this paper, suitable means are proposed to be introduced in fiber access infrastructures that will allow for shared utilization of the fibers while safeguarding the operational needs and business interests of the involved parties.

What versus where: Investigating how autobiographical memory retrieval differs when accessed with thematic versus spatial information.

PubMed

Sheldon, Signy; Chu, Sonja

2017-09-01

Autobiographical memory research has investigated how cueing distinct aspects of a past event can trigger different recollective experiences. This research has stimulated theories about how autobiographical knowledge is accessed and organized. Here, we test the idea that thematic information organizes multiple autobiographical events whereas spatial information organizes individual past episodes by investigating how retrieval guided by these two forms of information differs. We used a novel autobiographical fluency task in which participants accessed multiple memory exemplars to event theme and spatial (location) cues followed by a narrative description task in which they described the memories generated to these cues. Participants recalled significantly more memory exemplars to event theme than to spatial cues; however, spatial cues prompted faster access to past memories. Results from the narrative description task revealed that memories retrieved via event theme cues compared to spatial cues had a higher number of overall details, but those recalled to the spatial cues were recollected with a greater concentration on episodic details than those retrieved via event theme cues. These results provide evidence that thematic information organizes and integrates multiple memories whereas spatial information prompts the retrieval of specific episodic content from a past event.

Nonadditivity of quantum and classical capacities for entanglement breaking multiple-access channels and the butterfly network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grudka, Andrzej; National Quantum Information Centre of Gdansk, PL-81-824 Sopot; Horodecki, Pawel

2010-06-15

We analyze quantum network primitives which are entanglement breaking. We show superadditivity of quantum and classical capacity regions for quantum multiple-access channels and the quantum butterfly network. Since the effects are especially visible at high noise they suggest that quantum information effects may be particularly helpful in the case of the networks with occasional high noise rates. The present effects provide a qualitative borderline between superadditivities of bipartite and multipartite systems.

Code division multiple access signaling for modulated reflector technology

DOEpatents

Briles, Scott D [Los Alamos, NM

2012-05-01

A method and apparatus for utilizing code division multiple access in modulated reflectance transmissions comprises the steps of generating a phase-modulated reflectance data bit stream; modifying the modulated reflectance data bit stream; providing the modified modulated reflectance data bit stream to a switch that connects an antenna to an infinite impedance in the event a "+1" is to be sent, or connects the antenna to ground in the event a "0" or a "-1" is to be sent.

Public perceptions of key performance indicators of healthcare in Alberta, Canada.

PubMed

Northcott, Herbert C; Harvey, Michael D

2012-06-01

To examine the relationship between public perceptions of key performance indicators assessing various aspects of the health-care system. Cross-sequential survey research. Annual telephone surveys of random samples of adult Albertans selected by random digit dialing and stratified according to age, sex and region (n = 4000 for each survey year). The survey questionnaires included single-item measures of key performance indicators to assess public perceptions of availability, accessibility, quality, outcome and satisfaction with healthcare. Cronbach's α and factor analysis were used to assess the relationship between key performance indicators focusing on the health-care system overall and on a recent interaction with the health-care system. The province of Alberta, Canada during the years 1996-2004. Four thousand adults randomly selected each survey year. Survey questions measuring public perceptions of healthcare availability, accessibility, quality, outcome and satisfaction with healthcare. Factor analysis identified two principal components with key performance indicators focusing on the health system overall loading most strongly on the first component and key performance indicators focusing on the most recent health-care encounter loading most strongly on the second component. Assessments of the quality of care most recently received, accessibility of that care and perceived outcome of care tended to be higher than the more general assessments of overall health system quality and accessibility. Assessments of specific health-care encounters and more general assessments of the overall health-care system, while related, nevertheless comprise separate dimensions for health-care evaluation.

System Design and Cataloging Meet the User: User Interfaces to Online Public Access Catalogs.

ERIC Educational Resources Information Center

Yee, Martha M.

1991-01-01

Discusses features of online public access catalogs: (1) demonstration of relationships between records; (2) provision of entry vocabularies; (3) arrangement of multiple entries on the screen; (4) provision of access points; (5) display of single records; and (6) division of catalogs into separate files or indexes. User studies and other research…

Action Research to Improve Methods of Delivery and Feedback in an Access Grid Room Environment

ERIC Educational Resources Information Center

McArthur, Lynne C.; Klass, Lara; Eberhard, Andrew; Stacey, Andrew

2011-01-01

This article describes a qualitative study which was undertaken to improve the delivery methods and feedback opportunity in honours mathematics lectures which are delivered through Access Grid Rooms. Access Grid Rooms are facilities that provide two-way video and audio interactivity across multiple sites, with the inclusion of smart boards. The…

Access to Higher Education by the Luck of the Draw

ERIC Educational Resources Information Center

Stone, Peter

2013-01-01

Random selection is a fair way to break ties between applicants of equal merit seeking admission to institutions of higher education (with "merit" defined here in terms of the intrinsic contribution higher education would make to the applicant's life). Opponents of random selection commonly argue that differences in strength between…

Promoting Early Intervention Referral through a Randomized Controlled Home-Visiting Program

ERIC Educational Resources Information Center

Schwarz, Donald F.; O'Sullivan, Ann L.; Guinn, Judith; Mautone, Jennifer A.; Carlson, Elyse C.; Zhao, Huaqing; Zhang, Xuemei; Esposito, Tara L.; Askew, Megan; Radcliffe, Jerilynn

2012-01-01

The MOM Program is a randomized, controlled trial of an intervention to promote mothers' care for the health and development of their children, including accessing early intervention (EI) services. Study aims were to determine whether, relative to controls, this intervention increased receipt of and referral to EI services. Mothers (N = 302)…

Methods of Learning in Statistical Education: A Randomized Trial of Public Health Graduate Students

ERIC Educational Resources Information Center

Enders, Felicity Boyd; Diener-West, Marie

2006-01-01

A randomized trial of 265 consenting students was conducted within an introductory biostatistics course: 69 received eight small group cooperative learning sessions; 97 accessed internet learning sessions; 96 received no intervention. Effect on examination score (95% CI) was assessed by intent-to-treat analysis and by incorporating reported…

75 FR 69126 - Proposed Information Collection Request (ICR) for the Workforce Investment Act Random Assignment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-10

... Random Assignment Impact Evaluation of the Adult and Dislocated Worker Program; Comment Request AGENCY... fragmented system of employment and training programs under JTPA and providing universal access to basic (core) services. To determine whether the adult and dislocated worker services funded by Title I of the...

Radiation Exposure and Vascular Access in Acute Coronary Syndromes: The RAD-Matrix Trial.

PubMed

Sciahbasi, Alessandro; Frigoli, Enrico; Sarandrea, Alessandro; Rothenbühler, Martina; Calabrò, Paolo; Lupi, Alessandro; Tomassini, Francesco; Cortese, Bernardo; Rigattieri, Stefano; Cerrato, Enrico; Zavalloni, Dennis; Zingarelli, Antonio; Calabria, Paolo; Rubartelli, Paolo; Sardella, Gennaro; Tebaldi, Matteo; Windecker, Stephan; Jüni, Peter; Heg, Dik; Valgimigli, Marco

2017-05-23

It remains unclear whether radial access increases the risk of operator or patient radiation exposure compared to transfemoral access when performed by expert operators. This study sought to determine whether radial access increases radiation exposure. A total of 8,404 patients, with or without ST-segment elevation acute coronary syndrome, were randomly assigned to radial or femoral access for coronary angiography and percutaneous intervention, and collected fluoroscopy time and dose-area product (DAP). RAD-MATRIX is a radiation sub-study of the MATRIX (Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of AngioX) trial. We anticipated that 13 or more operators, each wearing a thorax (primary endpoint), wrist, and head (secondary endpoints) lithium fluoride thermoluminescent dosimeter, and randomizing at least 13 patients per access site, were needed to establish noninferiority of radial versus femoral access. Among 18 operators, performing 777 procedures in 767 patients, the noninferiority primary endpoint was not achieved (p value for noninferiority = 0.843). Operator equivalent dose at the thorax (77 μSv) was significantly higher with radial than femoral access (41 μSv; p = 0.02). After normalization of operator radiation dose by fluoroscopy time or DAP, the difference remained significant. Radiation dose at wrist or head did not differ between radial and femoral access. Thorax operator dose did not differ for right radial (84 μSv) compared to left radial access (52 μSv; p = 0.15). In the overall MATRIX population, fluoroscopy time and DAP were higher with radial compared to femoral access: 10 min versus 9 min (p < 0.0001) and 65 Gy·cm 2 versus 59 Gy·cm 2 (p = 0.0001), respectively. Compared to femoral access, radial access is associated with greater operator and patient radiation exposure when performed by expert operators in current practice. Radial operators and institutions should be sensitized towards radiation risks and adopt adjunctive radioprotective measures. (Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of AngioX; NCT101433627). Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Sensitivity Analysis of Multiple Informant Models When Data are Not Missing at Random

PubMed Central

Blozis, Shelley A.; Ge, Xiaojia; Xu, Shu; Natsuaki, Misaki N.; Shaw, Daniel S.; Neiderhiser, Jenae; Scaramella, Laura; Leve, Leslie; Reiss, David

2014-01-01

Missing data are common in studies that rely on multiple informant data to evaluate relationships among variables for distinguishable individuals clustered within groups. Estimation of structural equation models using raw data allows for incomplete data, and so all groups may be retained even if only one member of a group contributes data. Statistical inference is based on the assumption that data are missing completely at random or missing at random. Importantly, whether or not data are missing is assumed to be independent of the missing data. A saturated correlates model that incorporates correlates of the missingness or the missing data into an analysis and multiple imputation that may also use such correlates offer advantages over the standard implementation of SEM when data are not missing at random because these approaches may result in a data analysis problem for which the missingness is ignorable. This paper considers these approaches in an analysis of family data to assess the sensitivity of parameter estimates to assumptions about missing data, a strategy that may be easily implemented using SEM software. PMID:25221420

Distributed Synchronization in Networks of Agent Systems With Nonlinearities and Random Switchings.

PubMed

Tang, Yang; Gao, Huijun; Zou, Wei; Kurths, Jürgen

2013-02-01

In this paper, the distributed synchronization problem of networks of agent systems with controllers and nonlinearities subject to Bernoulli switchings is investigated. Controllers and adaptive updating laws injected in each vertex of networks depend on the state information of its neighborhood. Three sets of Bernoulli stochastic variables are introduced to describe the occurrence probabilities of distributed adaptive controllers, updating laws and nonlinearities, respectively. By the Lyapunov functions method, we show that the distributed synchronization of networks composed of agent systems with multiple randomly occurring nonlinearities, multiple randomly occurring controllers, and multiple randomly occurring updating laws can be achieved in mean square under certain criteria. The conditions derived in this paper can be solved by semi-definite programming. Moreover, by mathematical analysis, we find that the coupling strength, the probabilities of the Bernoulli stochastic variables, and the form of nonlinearities have great impacts on the convergence speed and the terminal control strength. The synchronization criteria and the observed phenomena are demonstrated by several numerical simulation examples. In addition, the advantage of distributed adaptive controllers over conventional adaptive controllers is illustrated.

Improving Global Access to New Vaccines: Intellectual Property, Technology Transfer, and Regulatory Pathways

PubMed Central

2014-01-01

The 2012 World Health Assembly Global Vaccine Action Plan called for global access to new vaccines within 5 years of licensure. Current approaches have proven insufficient to achieve sustainable vaccine pricing within such a timeline. Paralleling the successful strategy of generic competition to bring down drug prices, a clear consensus is emerging that market entry of multiple suppliers is a critical factor in expeditiously bringing down prices of new vaccines. In this context, key target objectives for improving access to new vaccines include overcoming intellectual property obstacles, streamlining regulatory pathways for biosimilar vaccines, and reducing market entry timelines for developing-country vaccine manufacturers by transfer of technology and know-how. I propose an intellectual property, technology, and know-how bank as a new approach to facilitate widespread access to new vaccines in low- and middle-income countries by efficient transfer of patented vaccine technologies to multiple developing-country vaccine manufacturers. PMID:25211753

Developing Access Control Model of Web OLAP over Trusted and Collaborative Data Warehouses

NASA Astrophysics Data System (ADS)

Fugkeaw, Somchart; Mitrpanont, Jarernsri L.; Manpanpanich, Piyawit; Juntapremjitt, Sekpon

This paper proposes the design and development of Role- based Access Control (RBAC) model for the Single Sign-On (SSO) Web-OLAP query spanning over multiple data warehouses (DWs). The model is based on PKI Authentication and Privilege Management Infrastructure (PMI); it presents a binding model of RBAC authorization based on dimension privilege specified in attribute certificate (AC) and user identification. Particularly, the way of attribute mapping between DW user authentication and privilege of dimensional access is illustrated. In our approach, we apply the multi-agent system to automate flexible and effective management of user authentication, role delegation as well as system accountability. Finally, the paper culminates in the prototype system A-COLD (Access Control of web-OLAP over multiple DWs) that incorporates the OLAP features and authentication and authorization enforcement in the multi-user and multi-data warehouse environment.

Improving global access to new vaccines: intellectual property, technology transfer, and regulatory pathways.

PubMed

Crager, Sara Eve

2014-11-01

The 2012 World Health Assembly Global Vaccine Action Plan called for global access to new vaccines within 5 years of licensure. Current approaches have proven insufficient to achieve sustainable vaccine pricing within such a timeline. Paralleling the successful strategy of generic competition to bring down drug prices, a clear consensus is emerging that market entry of multiple suppliers is a critical factor in expeditiously bringing down prices of new vaccines. In this context, key target objectives for improving access to new vaccines include overcoming intellectual property obstacles, streamlining regulatory pathways for biosimilar vaccines, and reducing market entry timelines for developing-country vaccine manufacturers by transfer of technology and know-how. I propose an intellectual property, technology, and know-how bank as a new approach to facilitate widespread access to new vaccines in low- and middle-income countries by efficient transfer of patented vaccine technologies to multiple developing-country vaccine manufacturers.

[Improving global access to new vaccines: intellectual property, technology transfer, and regulatory pathways].

PubMed

Crager, Sara Eve

2015-01-01

The 2012 World Health Assembly Global Vaccine Action Plan called for global access to new vaccines within 5 years of licensure. Current approaches have proven insufficient to achieve sustainable vaccine pricing within such a timeline. Paralleling the successful strategy of generic competition to bring down drug prices, a clear consensus is emerging that market entry of multiple suppliers is a critical factor in expeditiously bringing down prices of new vaccines. In this context, key target objectives for improving access to new vaccines include overcoming intellectual property obstacles, streamlining regulatory pathways for biosimilar vaccines, and reducing market entry timelines for developing-country vaccine manufacturers by transfer of technology and know-how. I propose an intellectual property, technology, and know-how bank as a new approach to facilitate widespread access to new vaccines in low- and middle-income countries by efficient transfer of patented vaccine technologies to multiple developing-country vaccine manufacturers.

Autocorrelation peaks in congruential pseudorandom number generators

NASA Technical Reports Server (NTRS)

Neuman, F.; Merrick, R. B.

1976-01-01

The complete correlation structure of several congruential pseudorandom number generators (PRNG) of the same type and small cycle length was studied to deal with the problem of congruential PRNG almost repeating themselves at intervals smaller than their cycle lengths, during simulation of bandpass filtered normal random noise. Maximum period multiplicative and mixed congruential generators were studied, with inferences drawn from examination of several tractable members of a class of random number generators, and moduli from 2 to the 5th power to 2 to the 9th power. High correlation is shown to exist in mixed and multiplicative congruential random number generators and prime moduli Lehmer generators for shifts a fraction of their cycle length. The random noise sequences in question are required when simulating electrical noise, air turbulence, or time variation of wind parameters.

FD/DAMA Scheme For Mobile/Satellite Communications

NASA Technical Reports Server (NTRS)

Yan, Tsun-Yee; Wang, Charles C.; Cheng, Unjeng; Rafferty, William; Dessouky, Khaled I.

1992-01-01

Integrated-Adaptive Mobile Access Protocol (I-AMAP) proposed to allocate communication channels to subscribers in first-generation MSAT-X mobile/satellite communication network. Based on concept of frequency-division/demand-assigned multiple access (FD/DAMA) where partition of available spectrum adapted to subscribers' demands for service. Requests processed, and competing requests resolved according to channel-access protocol, or free-access tree algorithm described in "Connection Protocol for Mobile/Satellite Communications" (NPO-17735). Assigned spectrum utilized efficiently.

Coherent optical pulse sequencer for quantum applications.

PubMed

Hosseini, Mahdi; Sparkes, Ben M; Hétet, Gabriel; Longdell, Jevon J; Lam, Ping Koy; Buchler, Ben C

2009-09-10

The bandwidth and versatility of optical devices have revolutionized information technology systems and communication networks. Precise and arbitrary control of an optical field that preserves optical coherence is an important requisite for many proposed photonic technologies. For quantum information applications, a device that allows storage and on-demand retrieval of arbitrary quantum states of light would form an ideal quantum optical memory. Recently, significant progress has been made in implementing atomic quantum memories using electromagnetically induced transparency, photon echo spectroscopy, off-resonance Raman spectroscopy and other atom-light interaction processes. Single-photon and bright-optical-field storage with quantum states have both been successfully demonstrated. Here we present a coherent optical memory based on photon echoes induced through controlled reversible inhomogeneous broadening. Our scheme allows storage of multiple pulses of light within a chosen frequency bandwidth, and stored pulses can be recalled in arbitrary order with any chosen delay between each recalled pulse. Furthermore, pulses can be time-compressed, time-stretched or split into multiple smaller pulses and recalled in several pieces at chosen times. Although our experimental results are so far limited to classical light pulses, our technique should enable the construction of an optical random-access memory for time-bin quantum information, and have potential applications in quantum information processing.

An Educational Rationale for Deaf Students with Multiple Disabilities

ERIC Educational Resources Information Center

Ewing, Karen M.; Jones, Thomas W.

2003-01-01

Deaf students with multiple disabilities have a long history of limited opportunity, including limited access to educational opportunities available to their deaf peers. This article places the individual needs of deaf students with multiple disabilities in the context that guides much of deaf education--the importance of language acquisition.…

A matrix contraction process

NASA Astrophysics Data System (ADS)

Wilkinson, Michael; Grant, John

2018-03-01

We consider a stochastic process in which independent identically distributed random matrices are multiplied and where the Lyapunov exponent of the product is positive. We continue multiplying the random matrices as long as the norm, ɛ, of the product is less than unity. If the norm is greater than unity we reset the matrix to a multiple of the identity and then continue the multiplication. We address the problem of determining the probability density function of the norm, \

Prepare, a randomized trial to promote and evaluate weight loss among overweight and obese women planning pregnancy: Study design and rationale

PubMed Central

Vesco, Kimberly K.; Funk, Kristine L.; Karanja, Njeri; Smith, Ning; Stevens, Victor J.

2017-01-01

Background Women who are overweight or have obesity at pregnancy onset, and those who gain excessive weight during pregnancy, are at increased risk of pregnancy-related complications and large for gestational age infants. Objective This report describes methodology for the Prepare study, a randomized, controlled clinical trial testing a preconception and pregnancy weight management program for women who are overweight or have obesity (BMI ≥ 27 kg/m2). Outcomes This trial examines multiple pregnancy and neonatal outcomes, with the primary outcome being gestational weight gain (GWG). Secondary outcomes include change in weight before conception, offspring birth weight adjusted for gestational age, offspring weight for length, and pregnancy diet quality and physical activity level. Methods Nonpregnant women who anticipate becoming pregnant in the next 2 years are randomly assigned to an intervention program or a usual care control condition. Intervention participants receive weight management counseling by telephone before and during pregnancy, with weekly contacts during the first 6 months and monthly contacts for the next 18 months. Intervention participants also have unlimited access to a study website that provides self-management tools. All participants who become pregnant are contacted at 20 weeks' gestation to assess physical activity levels and dietary habits. All other outcome data are obtained from medical records. Intervention satisfaction is assessed via questionnaire. Summary This clinical trial tests the efficacy of an intervention program designed to help overweight and obese women achieve healthy lifestyle changes that will result in a healthy weight prior to pregnancy and appropriate weight gain during pregnancy. PMID:27394386

Fe en Accion/Faith in Action: Design and implementation of a church-based randomized trial to promote physical activity and cancer screening among churchgoing Latinas

PubMed Central

Arredondo, Elva M.; Haughton, Jessica; Ayala, Guadalupe X.; Slymen, Donald J.; Sallis, James F.; Burke, Kari; Holub, Christina; Chanson, Dayana; Perez, Lilian G.; Valdivia, Rodrigo; Ryan, Sherry; Elder, John

2015-01-01

Objectives To describe both conditions of a two-group randomized trial, one that promotes physical activity and one that promotes cancer screening, among churchgoing Latinas. The trial involves promotoras (community health workers) targeting multiple levels of the Ecological Model. This trial builds on formative and pilot research findings. Design Sixteen churches were randomly assigned to either the physical activity intervention or cancer screening comparison condition (approximately 27 women per church). In both conditions, promotoras from each church intervened at the individual- (e.g., beliefs), interpersonal- (e.g., social support), and environmental- (e.g., park features and access to health care) levels to affect change on target behaviors. Measurements The study’s primary outcome is min/wk of moderate-to-vigorous physical activity (MVPA) at baseline and 12 and 24 months following implementation of intervention activities. We enrolled 436 Latinas (aged 18–65 years) who engaged in less than 250 min/wk of MVPA at baseline as assessed by accelerometer, attended church at least four times per month, lived near their church, and did not have a health condition that could prevent them from participating in physical activity. Participants were asked to complete measures assessing physical activity and cancer screening as well as their correlates at 12- and 24-months. Summary Findings from the current study will address gaps in research by showing the long term effectiveness of multi-level faith-based interventions promoting physical activity and cancer screening among Latino communities. PMID:26358535

Optimizing the delivery of contraceptives in low- and middle-income countries through task shifting: a systematic review of effectiveness and safety.

PubMed

Polus, Stephanie; Lewin, Simon; Glenton, Claire; Lerberg, Priya M; Rehfuess, Eva; Gülmezoglu, A Metin

2015-04-01

To assess the effectiveness and safety of task shifting for the delivery of injectable contraceptives, contraceptive implants, intrauterine devices (IUDs), tubal ligation and vasectomy in low- and middle-income countries. Multiple electronic databases were searched up to 25 May 2012 for studies which had assessed the delivery of contraceptives by health workers with lower levels of training, compared to delivery by health workers usually assigned this role, or compared to no organized provision of contraceptives. We included randomized controlled trials, non-randomized controlled trials, controlled before-after studies, and interrupted time series. Data were extracted using a standard form and the certainty of the evidence found was assessed using GRADE. We identified six randomized controlled trials published between 1977 and 1995 that assessed the safety and effectiveness of task shifting for the delivery of long-term contraceptives. Two studies assessed IUD insertion by nurses compared to doctors, two assessed IUD insertion by auxiliary nurse-midwives compared to doctors, one assessed tubal ligation by midwives compared to doctors, and one assessed the delivery of vasectomy by medical students compared to doctors. In general, little or no difference was found in contraceptive outcomes between cadres. Study design limitations and the low number of eligible studies, however, allow only limited conclusions to be drawn. The findings indicate that task shifting for the delivery of long-term contraceptives may be a safe and effective approach to increasing access to contraception. Further research is needed because the certainty of the evidence identified is variable.

Weighted Scaling in Non-growth Random Networks

NASA Astrophysics Data System (ADS)

Chen, Guang; Yang, Xu-Hua; Xu, Xin-Li

2012-09-01

We propose a weighted model to explain the self-organizing formation of scale-free phenomenon in non-growth random networks. In this model, we use multiple-edges to represent the connections between vertices and define the weight of a multiple-edge as the total weights of all single-edges within it and the strength of a vertex as the sum of weights for those multiple-edges attached to it. The network evolves according to a vertex strength preferential selection mechanism. During the evolution process, the network always holds its total number of vertices and its total number of single-edges constantly. We show analytically and numerically that a network will form steady scale-free distributions with our model. The results show that a weighted non-growth random network can evolve into scale-free state. It is interesting that the network also obtains the character of an exponential edge weight distribution. Namely, coexistence of scale-free distribution and exponential distribution emerges.

Worksite Environmental Interventions for Obesity Prevention and Control: Evidence from Group Randomized Trials.

PubMed

Fernandez, Isabel Diana; Becerra, Adan; Chin, Nancy P

2014-06-01

Worksites provide multiple advantages to prevent and treat obesity and to test environmental interventions to tackle its multiple causal factors. We present a literature review of group-randomized and non-randomized trials that tested worksite environmental, multiple component interventions for obesity prevention and control paying particular attention to the conduct of formative research prior to intervention development. The evidence on environmental interventions on measures of obesity appears to be strong since most of the studies have a low (4/8) and unclear (2/8) risk of bias. Among the studies reviewed whose potential risk of bias was low, the magnitude of the effect was modest and sometimes in the unexpected direction. None of the four studies describing an explicit formative research stage with clear integration of findings into the intervention was able to demonstrate an effect on the main outcome of interest. We present alternative explanation for the findings and recommendations for future research.

A multiple camera tongue switch for a child with severe spastic quadriplegic cerebral palsy.

PubMed

Leung, Brian; Chau, Tom

2010-01-01

The present study proposed a video-based access technology that facilitated a non-contact tongue protrusion access modality for a 7-year-old boy with severe spastic quadriplegic cerebral palsy (GMFCS level 5). The proposed system featured a centre camera and two peripheral cameras to extend coverage of the frontal face view of this user for longer durations. The child participated in a descriptive case study. The participant underwent 3 months of tongue protrusion training while the multiple camera tongue switch prototype was being prepared. Later, the participant was brought back for five experiment sessions where he worked on a single-switch picture matching activity, using the multiple camera tongue switch prototype in a controlled environment. The multiple camera tongue switch achieved an average sensitivity of 82% and specificity of 80%. In three of the experiment sessions, the peripheral cameras were associated with most of the true positive switch activations. These activations would have been missed by a centre-camera-only setup. The study demonstrated proof-of-concept of a non-contact tongue access modality implemented by a video-based system involving three cameras and colour video processing.

An integrated voice and data multiple-access scheme for a land-mobile satellite system

NASA Technical Reports Server (NTRS)

Li, V. O. K.; Yan, T.-Y.

1984-01-01

An analytical study is performed of the satellite requirements for a land mobile satellite system (LMSS). The spacecraft (MSAT-X) would be in GEO and would be compatible with multiple access by mobile radios and antennas and fixed stations. The FCC has received a petition from NASA to reserve the 821-825 and 866-870 MHz frequencies for the LMSS, while communications with fixed earth stations would be in the Ku band. MSAT-X transponders would alter the frequencies of signal and do no processing in the original configuration considered. Channel use would be governed by an integrated demand-assigned, multiple access protocol, which would divide channels into reservation and information channels, governed by a network management center. Further analyses will cover tradeoffs between data and voice users, probability of blocking, and the performance impacts of on-board switching and variable bandwidth assignment. Initial calculations indicate that a large traffic volume can be handled with acceptable delays and voice blocking probabilities.

An integrated voice and data multiple-access scheme for a land-mobile satellite system

NASA Astrophysics Data System (ADS)

Li, V. O. K.; Yan, T.-Y.

1984-11-01

An analytical study is performed of the satellite requirements for a land mobile satellite system (LMSS). The spacecraft (MSAT-X) would be in GEO and would be compatible with multiple access by mobile radios and antennas and fixed stations. The FCC has received a petition from NASA to reserve the 821-825 and 866-870 MHz frequencies for the LMSS, while communications with fixed earth stations would be in the Ku band. MSAT-X transponders would alter the frequencies of signal and do no processing in the original configuration considered. Channel use would be governed by an integrated demand-assigned, multiple access protocol, which would divide channels into reservation and information channels, governed by a network management center. Further analyses will cover tradeoffs between data and voice users, probability of blocking, and the performance impacts of on-board switching and variable bandwidth assignment. Initial calculations indicate that a large traffic volume can be handled with acceptable delays and voice blocking probabilities.

User needs for propagation data

NASA Technical Reports Server (NTRS)

Sullivan, Thomas M.

1993-01-01

New and refined models of radio signal propagation phenomena are needed to support studies of evolving satellite services and systems. Taking an engineering perspective, applications for propagation measurements and models in the context of various types of analyses that are of ongoing interest are reviewed. Problems that were encountered in the signal propagation aspects of these analyses are reviewed, and potential solutions to these problems are discussed. The focus is on propagation measurements and models needed to support design and performance analyses of systems in the Mobile-Satellite Service (MSS) operating in the 1-3 GHz range. These systems may use geostationary or non-geostationary satellites and Frequency Division Multiple Access (FDMA), Time Division Multiple Access Digital (TDMA), or Code Division Multiple Access (CDMA) techniques. Many of the propagation issues raised in relation to MSS are also pertinent to other services such as broadcasting-satellite (sound) at 2310-2360 MHz. In particular, services involving mobile terminals or terminals with low gain antennas are of concern.

Transparent data service with multiple wireless access

NASA Technical Reports Server (NTRS)

Dean, Richard A.; Levesque, Allen H.

1993-01-01

The rapid introduction of digital wireless networks is an important part of the emerging digital communications scene. The introduction of Digital Cellular, LEO and GEO Satellites, and Personal Communications Services poses both a challenge and an opportunity for the data user. On the one hand wireless access will introduce significant new portable data services such as personal notebooks, paging, E-mail, and fax that will put the information age in the user's pocket. On the other hand the challenge of creating a seamless and transparent environment for the user in multiple access environments and across multiple network connections is formidable. A summary of the issues associated with developing techniques and standards that can support transparent and seamless data services is presented. The introduction of data services into the radio world represents a unique mix of RF channel problems, data protocol issues, and network issues. These problems require that experts from each of these disciplines fuse the individual technologies to support these services.

Wild versus domestic prey in the diet of reintroduced tigers (Panthera tigris) in the livestock-dominated multiple-use forests of Panna Tiger Reserve, India.

PubMed

Kolipaka, S S; Tamis, W L M; van 't Zelfde, M; Persoon, G A; de Iongh, H H

2017-01-01

Grazing livestock in openly accessible areas is a common practice in the multiple-use forests of India; however, its compatibility with the reintroduction of tigers to these areas requires examination. Here, we investigated the diet of tigers in a livestock-dominated multiple-use buffer zone of the Panna Tiger Reserve, India. We hypothesised that the presence of feral cattle, along with open-access grazing practices in multiple-use forests, would increase the incidence of predation on livestock by tigers, even when wild prey are available. We used generalised linear models to test whether predation of livestock versus wild animals was influenced by (1) the sex and age class of tigers, (2) season, and (3) the distance of prey from the core-zone boundary of the reserve. Overall, sub-adult tigers and male tigers killed more livestock than wild prey, even when wild prey was available. In the winter and rainy seasons livestock were killed in higher numbers in the buffer zone than in summers, this may be because of the seasonally changing livestock herding patterns in the area. Further, with increasing distance from the core-zone boundary, all tigers killed more livestock, possibly because livestock were more easily accessible than wild prey. Our results show that open-access and unregulated livestock grazing is not currently compatible with large carnivore conservation in the same landscape. Such practices will lead to an increase in negative tiger-human-livestock interactions. In conclusion, we suggest the need to encourage locals to corral valuable cattle, leaving feral/unwanted livestock for tigers. This simple strategy would benefit both local inhabitants and tiger conservation in the multiple-use forests of India.

Wild versus domestic prey in the diet of reintroduced tigers (Panthera tigris) in the livestock-dominated multiple-use forests of Panna Tiger Reserve, India

PubMed Central

Tamis, W. L. M.; van ‘t Zelfde, M.; Persoon, G. A.; de Iongh, H. H.

2017-01-01

Grazing livestock in openly accessible areas is a common practice in the multiple-use forests of India; however, its compatibility with the reintroduction of tigers to these areas requires examination. Here, we investigated the diet of tigers in a livestock-dominated multiple-use buffer zone of the Panna Tiger Reserve, India. We hypothesised that the presence of feral cattle, along with open-access grazing practices in multiple-use forests, would increase the incidence of predation on livestock by tigers, even when wild prey are available. We used generalised linear models to test whether predation of livestock versus wild animals was influenced by (1) the sex and age class of tigers, (2) season, and (3) the distance of prey from the core-zone boundary of the reserve. Overall, sub-adult tigers and male tigers killed more livestock than wild prey, even when wild prey was available. In the winter and rainy seasons livestock were killed in higher numbers in the buffer zone than in summers, this may be because of the seasonally changing livestock herding patterns in the area. Further, with increasing distance from the core-zone boundary, all tigers killed more livestock, possibly because livestock were more easily accessible than wild prey. Our results show that open-access and unregulated livestock grazing is not currently compatible with large carnivore conservation in the same landscape. Such practices will lead to an increase in negative tiger-human-livestock interactions. In conclusion, we suggest the need to encourage locals to corral valuable cattle, leaving feral/unwanted livestock for tigers. This simple strategy would benefit both local inhabitants and tiger conservation in the multiple-use forests of India. PMID:28379997

Autoshaping induces ethanol drinking in nondeprived rats: evidence of long-term retention but no induction of ethanol preference.

PubMed

Tomie, Arthur; Kuo, Teresa; Apor, Khristine R; Salomon, Kimberly E; Pohorecky, Larissa A

2004-04-01

The effects of autoshaping procedures (paired vs. random) and sipper fluid (ethanol vs. water) on sipper-directed drinking were evaluated in male Long-Evans rats maintained with free access to food and water. For the paired/ethanol group (n=16), autoshaping procedures consisted of presenting the ethanol sipper (containing 0% to 28% unsweetened ethanol) conditioned stimulus (CS) followed by the response-independent presentation of food unconditioned stimulus (US). The random/ethanol group (n=8) received the sipper CS and food US randomly with respect to one another. The paired/water group (n=8) received only water in the sipper CS. The paired/ethanol group showed higher grams per kilogram ethanol intake than the random/ethanol group did at ethanol concentrations of 8% to 28%. The paired/ethanol group showed higher sipper CS-directed milliliter fluid consumption than the paired/water group did at ethanol concentrations of 1% to 6%, and 15%, 16%, 18%, and 20%. Following a 42-day retention interval, the paired/ethanol group showed superior retention of CS-directed drinking of 18% ethanol, relative to the random/ethanol group, and superior retention of CS-directed milliliter fluid drinking relative to the paired/water group. When tested for home cage ethanol preference using limited access two-bottle (28% ethanol vs. water) procedures, the paired/ethanol and random/ethanol groups did not differ on any drinking measures.

Effect of portal access system and surgery type on surgery times during laparoscopic ovariectomy and salpingectomy in captive African lions and cheetahs.

PubMed

Hartman, Marthinus Jacobus; Monnet, Eric; Kirberger, Robert Murco; Schoeman, Johan Petrus

2016-03-02

A prospective randomized study was used to compare surgery times for laparoscopic ovariectomy and salpingectomy in female African lion (Panthera leo) (n = 14) and cheetah (Acinonyx jubatus) (n = 20) and to compare the use of a multiple portal access system (MPAS) and single portal access system (SPAS) between groups. Two different portal techniques were used, namely MPAS (three separate ports) in lions and SPAS (SILS™ port) in cheetahs, using standard straight laparoscopic instruments. Portal access system and first ovary was not randomized. Five different surgery times were compared for the two different procedures as well as evaluating the use and application of MPAS and SPAS. Carbon dioxide volumes for lions were recorded. In adult lionesses operative time (OPT) (P = 0.016) and total surgical time (TST) (P = 0.032) were significantly shorter for salpingectomy compared to ovariectomy. Similarly in cheetahs OPT (P = 0.001) and TST (P = 0.005) were also shorter for salpingectomy compared to ovariectomy. In contrast, in lion cubs no difference was found in surgery times for ovariectomy and salpingectomy. Total unilateral procedure time was shorter than the respective bilateral time for both procedures (P = 0.019 and P = 0.001) respectively and unilateral salpingectomy was also faster than unilateral ovariectomy (P = 0.035) in cheetahs. Port placement time, suturing time and TST were significantly shorter for SPAS compared to MPAS (P = 0.008). There was, however, no difference in OPT between SPAS and MPAS. Instrument cluttering with SPAS was found to be negligible. There was no difference in mean volume CO2 required to complete ovariectomy in lions but the correlation between bodyweight and total volume of CO2 in lions was significant (rs = 0.867; P = 0.002). Laparoscopic salpingectomy was faster than ovariectomy in both adult lions and cheetahs. Using SPAS, both unilateral procedures were faster than bilateral procedures in cheetahs. Placement and suturing of SPAS in cheetahs was easier and faster compared to three separate ports in lions and lion cubs. The use of standard straight instruments during SPAS did not prolong surgery. Surgery was faster in cubs and CO2 required for laparoscopic sterilization in lions could be determined. Predictable surgery times and CO2 volumes will facilitate the accurate planning and execution of surgery in lions and cheetahs.

Summer School Effects in a Randomized Field Trial

ERIC Educational Resources Information Center

Zvoch, Keith; Stevens, Joseph J.

2013-01-01

This field-based randomized trial examined the effect of assignment to and participation in summer school for two moderately at-risk samples of struggling readers. Application of multiple regression models to difference scores capturing the change in summer reading fluency revealed that kindergarten students randomly assigned to summer school…

A Preliminary Investigation of a Randomized Dependent Group Contingency for Hallway Transitions

ERIC Educational Resources Information Center

Deshais, Meghan A.; Fisher, Alyssa B.; Kahng, SungWoo

2018-01-01

We conducted a preliminary investigation of a randomized dependent group contingency to decrease disruptive behavior during hallway transitions. Two first-graders, identified by their classroom teacher, participated in this study. A multiple baseline across transitions was used to evaluate the effects of the randomized dependent group contingency…

Schramm-Loewner evolution of the accessible perimeter of isoheight lines of correlated landscapes

NASA Astrophysics Data System (ADS)

Posé, N.; Schrenk, K. J.; Araújo, N. A. M.; Herrmann, H. J.

Real landscapes exhibit long-range height-height correlations, which are quantified by the Hurst exponent H. We give evidence that for negative H, in spite of the long-range nature of correlations, the statistics of the accessible perimeter of isoheight lines is compatible with Schramm-Loewner evolution curves and therefore can be mapped to random walks, their fractal dimension determining the diffusion constant. Analytic results are recovered for H=-1 and H=0 and a conjecture is proposed for the values in between. By contrast, for positive H, we find that the random walk is not Markovian but strongly correlated in time. Theoretical and practical implications are discussed.

Application of holographic optical techniques to bulk memory.

NASA Technical Reports Server (NTRS)

Anderson, L. K.

1971-01-01

Current efforts to exploit the spatial redundancy and built-in imaging of holographic optical techniques to provide high information densities without critical alignment and tight mechanical tolerances are reviewed. Read-write-erase in situ operation is possible but is presently impractical because of limitations in available recording media. As these are overcome, it should prove feasible to build holographic bulk memories with mechanically replaceable hologram plates featuring very fast (less than 2 microsec) random access to large (greater than 100 million bit) data blocks and very high throughput (greater than 500 Mbit/sec). Using volume holographic storage it may eventually be possible to realize random-access mass memories which require no mechanical motion and yet provide very high capacity.

Parsing Citations in Biomedical Articles Using Conditional Random Fields

PubMed Central

Zhang, Qing; Cao, Yong-Gang; Yu, Hong

2011-01-01

Citations are used ubiquitously in biomedical full-text articles and play an important role for representing both the rhetorical structure and the semantic content of the articles. As a result, text mining systems will significantly benefit from a tool that automatically extracts the content of a citation. In this study, we applied the supervised machine-learning algorithms Conditional Random Fields (CRFs) to automatically parse a citation into its fields (e.g., Author, Title, Journal, and Year). With a subset of html format open-access PubMed Central articles, we report an overall 97.95% F1-score. The citation parser can be accessed at: http://www.cs.uwm.edu/~qing/projects/cithit/index.html. PMID:21419403

Health and agricultural productivity: Evidence from Zambia.

PubMed

Fink, Günther; Masiye, Felix

2015-07-01

We evaluate the productivity effects of investment in preventive health technology through a randomized controlled trial in rural Zambia. In the experiment, access to subsidized bed nets was randomly assigned at the community level; 516 farmers were followed over a one-year farming period. We find large positive effects of preventative health investment on productivity: among farmers provided with access to free nets, harvest value increased by US$ 76, corresponding to about 14.7% of the average output value. While only limited information was collected on farming inputs, shifts in the extensive and the intensive margins of labor supply appear to be the most likely mechanism underlying the productivity improvements observed. Copyright © 2015 Elsevier B.V. All rights reserved.

Community Impact of Pharmacy-Randomized Intervention to Improve Access to Syringes and Services for Injection Drug Users

ERIC Educational Resources Information Center

Crawford, Natalie D.; Amesty, Silvia; Rivera, Alexis V.; Harripersaud, Katherine; Turner, Alezandria; Fuller, Crystal M.

2014-01-01

Objectives: In an effort to reduce HIV transmission among injection drug users (IDUs), New York State deregulated pharmacy syringe sales in 2001 through the Expanded Syringe Access Program by removing the requirement of a prescription. With evidence suggesting pharmacists' ability to expand their public health role, a structural, pharmacy-based…

Test Procedures for Semiconductor Random Access Memories

DTIC Science & Technology

1979-11-01

of each cell exactly complement to each other, the read operations on the base cell in (g) of step 2 following operations ko S odd and in (p) of step...contents of Sko (these cells this address. Furthermore, when more than one contained I at test time and even if the con- cell is accessed then the output

Rural Youths' Participation in Agriculture: Prospects, Challenges and the Implications for Policy in Nigeria

ERIC Educational Resources Information Center

Auta, Sarah Jehu; Abdullahi, Yusuf M.; Nasiru, Mohammed

2010-01-01

The study aimed at assessing rural youth participation in agriculture, their access to production resources and services and the effects of youths' access to inputs and services on farm productivity and youths' welfare. The study was conducted in three states (each randomly selected from the three agro-ecological zones of northern Nigeria). Two…

Socio-Economic Background and Access to Internet as Correlates of Students' Achievement in Agricultural Science

ERIC Educational Resources Information Center

Adegoke, Sunday Paul; Osokoya, Modupe M.

2015-01-01

This study investigated access to internet and socio-economic background as correlates of students' achievement in Agricultural Science among selected Senior Secondary Schools Two Students in Ogbomoso South and North Local Government Areas. The study adopted multi-stage sampling technique. Simple random sampling was used to select 30 students from…

The base rates and factors associated with reported access to firearms in psychiatric inpatients.

PubMed

Kolla, Bhanu Prakash; O'Connor, Stephen S; Lineberry, Timothy W

2011-01-01

The aim of this study was to define whether specific patient demographic groups, diagnoses or other factors are associated with psychiatric inpatients reporting firearms access. A retrospective medical records review study was conducted using information on access to firearms from electronic medical records for all patients 16 years and older admitted between July 2007 and May 2008 at the Mayo Clinic Psychiatric Hospital in Rochester, MN. Data were obtained only on patients providing authorization for record review. Data were analyzed using univariate and multivariate logistic regression analyses accounting for gender, diagnostic groups, comorbid substance use, history of suicide attempts and family history of suicide/suicide attempts. Seventy-four percent (1169/1580) of patients provided research authorization. The ratio of men to women was identical in both research and nonresearch authorization groups. There were 14.6% of inpatients who reported firearms access. In univariate analysis, men were more likely (P<.0001) to report access than women, and a history of previous suicide attempt(s) was associated with decreased access (P=.02). Multiple logistic regression analyses controlling for other factors found females and patients with history of previous suicide attempt(s) less likely to report access, while patients with a family history of suicide or suicide attempts reported increased firearms access. Diagnostic groups were not associated with access on univariate or multiple logistic regression analyses. Men and inpatients with a family history of suicide/suicide attempts were more likely to report firearms access. Clinicians should develop standardized systems of identification of firearms access and provide guidance on removal. Copyright © 2011 Elsevier Inc. All rights reserved.

Cost-effectiveness of an adjustment group for people with multiple sclerosis and low mood: a randomized trial.

PubMed

Humphreys, Ioan; Drummond, Avril E R; Phillips, Ceri; Lincoln, Nadina B

2013-11-01

To evaluate the cost effectiveness of a psychological adjustment group shown to be clinically effective in comparison with usual care for people with multiple sclerosis. Randomized controlled trial with comparison of costs and calculation of incremental cost effectiveness ratio. Community. People with multiple sclerosis were screened on the General Health Questionnaire 12 and Hospital Anxiety and Depression Scale, and those with low mood were recruited. Participants randomly allocated to the adjustment group received six group treatment sessions. The control group received usual care, which did not include psychological interventions. Outcomes were assessed four and eight months after randomization, blind to group allocation. The costs were assessed from a service use questionnaire and information provided on medication. Quality of life was assessed using the EQ-5D. Of the 311 patients identified, 221 (71%) met the criteria for having low mood. Of these, 72 were randomly allocated to receive treatment and 79 to usual care. Over eight months follow-up there was a decrease in the combined average costs of £378 per intervention respondent and an increase in the costs of £297 per patient in the control group, which was a significant difference (p=0.03). The incremental cost-effectiveness ratio indicated that the cost per point reduction on the Beck depression inventory-II was £118. In the short term, the adjustment group programme was cost effective when compared with usual care, for people with multiple sclerosis presenting with low mood. The longer-term costs need to be assessed.

Multiple filters affect tree species assembly in mid-latitude forest communities.

PubMed

Kubota, Y; Kusumoto, B; Shiono, T; Ulrich, W

2018-05-01

Species assembly patterns of local communities are shaped by the balance between multiple abiotic/biotic filters and dispersal that both select individuals from species pools at the regional scale. Knowledge regarding functional assembly can provide insight into the relative importance of the deterministic and stochastic processes that shape species assembly. We evaluated the hierarchical roles of the α niche and β niches by analyzing the influence of environmental filtering relative to functional traits on geographical patterns of tree species assembly in mid-latitude forests. Using forest plot datasets, we examined the α niche traits (leaf and wood traits) and β niche properties (cold/drought tolerance) of tree species, and tested non-randomness (clustering/over-dispersion) of trait assembly based on null models that assumed two types of species pools related to biogeographical regions. For most plots, species assembly patterns fell within the range of random expectation. However, particularly for cold/drought tolerance-related β niche properties, deviation from randomness was frequently found; non-random clustering was predominant in higher latitudes with harsh climates. Our findings demonstrate that both randomness and non-randomness in trait assembly emerged as a result of the α and β niches, although we suggest the potential role of dispersal processes and/or species equalization through trait similarities in generating the prevalence of randomness. Clustering of β niche traits along latitudinal climatic gradients provides clear evidence of species sorting by filtering particular traits. Our results reveal that multiple filters through functional niches and stochastic processes jointly shape geographical patterns of species assembly across mid-latitude forests.

Health care access among Mexican Americans with different health insurance coverage.

PubMed

Treviño, R P; Treviño, F M; Medina, R; Ramirez, G; Ramirez, R R

1996-05-01

This study describes the rates of health care access among Mexican Americans with different health insurance coverage. An interview questionnaire was used to collect information regarding sociodemographics, perceived health status, health insurance coverage, and sources of health care from a random sample of 501 Mexican Americans from San Antonio, Texas. Health care access was determined more by having health insurance coverage than by health care needs. Poor Mexican Americans with health insurance had higher health care access rates than did poor Mexican Americans without health insurance. Health care access may improve health care outcomes, but more comprehensive community-based campaigns to promote health and better use of health services in underprivileged populations should be developed.

Processing speed and working memory training in multiple sclerosis: a double-blind randomized controlled pilot study.

PubMed

Hancock, Laura M; Bruce, Jared M; Bruce, Amanda S; Lynch, Sharon G

2015-01-01

Between 40-65% of multiple sclerosis patients experience cognitive deficits, with processing speed and working memory most commonly affected. This pilot study investigated the effect of computerized cognitive training focused on improving processing speed and working memory. Participants were randomized into either an active or a sham training group and engaged in six weeks of training. The active training group improved on a measure of processing speed and attention following cognitive training, and data trended toward significance on measures of other domains. Results provide preliminary evidence that cognitive training with multiple sclerosis patients may produce moderate improvement in select areas of cognitive functioning.

"My Daughter Does Not Know How to Make the Chappati": Understanding Food Access among African Immigrants in Lewiston, Maine

ERIC Educational Resources Information Center

Jacobus, Michelle Vazquez; Ahmed, Hussein; Jalali, Reza

2013-01-01

Food access for Maine's growing African refugee population reflects multiple levels of general access to society. To better understand the challenges and opportunities unique to this community, a multidisciplinary team of students, faculty, and community partners integrated the expertise of local residents with the results of a food assessment of…

Effectiveness of Two Web-Based Interventions for Chronic Cancer-Related Fatigue Compared to an Active Control Condition: Results of the "Fitter na kanker" Randomized Controlled Trial.

PubMed

Bruggeman-Everts, Fieke Z; Wolvers, Marije D J; van de Schoot, Rens; Vollenbroek-Hutten, Miriam M R; Van der Lee, Marije L

2017-10-19

Approximately one third of all patients who have been successfully treated for cancer suffer from chronic cancer-related fatigue (CCRF). Effective and easily accessible interventions are needed for these patients. The current paper reports on the results of a 3-armed randomized controlled trial investigating the clinical effectiveness of two different guided Web-based interventions for reducing CCRF compared to an active control condition. Severely fatigued cancer survivors were recruited via online and offline channels, and self-registered on an open-access website. After eligibility checks, 167 participants were randomized via an embedded automated randomization function into: (1) physiotherapist-guided Ambulant Activity Feedback (AAF) therapy encompassing the use of an accelerometer (n=62); (2) psychologist-guided Web-based mindfulness-based cognitive therapy (eMBCT; n=55); or (3) an unguided active control condition receiving psycho-educational emails (n=50). All interventions lasted nine weeks. Fatigue severity was self-assessed using the Checklist Individual Strength - Fatigue Severity subscale (primary outcome) six times from baseline (T0b) to six months (T2). Mental health was self-assessed three times using the Hospital Anxiety and Depression Scale and Positive and Negative Affect Schedule (secondary outcome). Treatment dropout was investigated. Multiple group latent growth curve analysis, corrected for individual time between assessments, showed that fatigue severity decreased significantly more in the AAF and eMBCT groups compared to the psycho-educational group. The analyses were checked by a researcher who was blind to allocation. Clinically relevant changes in fatigue severity were observed in 66% (41/62) of patients in AAF, 49% (27/55) of patients in eMBCT, and 12% (6/50) of patients in psycho-education. Dropout was 18% (11/62) in AAF, mainly due to technical problems and poor usability of the accelerometer, and 38% (21/55) in eMBCT, mainly due to the perceived high intensity of the program. Both the AAF and eMBCT interventions are effective for managing fatigue severity compared to receiving psycho-educational emails. Trialregister.nl NTR3483; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3483 (Archived by WebCite at http://www.webcitation.org/6NWZqon3o). ©Fieke Z. Bruggeman-Everts, Marije D. J. Wolvers, Rens van de Schoot, Miriam M. R. Vollenbroek-Hutten, Marije L. Van der Lee. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 19.10.2017.

Scaling Academic Planning in Community College: A Randomized Controlled Trial. REL 2017-204

ERIC Educational Resources Information Center

Visher, Mary G.; Mayer, Alexander K.; Johns, Michael; Rudd, Timothy; Levine, Andrew; Rauner, Mary

2016-01-01

Community college students often lack an academic plan to guide their choices of coursework to achieve their educational goals, in part because counseling departments typically lack the capacity to advise students at scale. This randomized controlled trial tests the impact of guaranteed access to one of two alternative counseling sessions (group…

Transfer Incentives for High-Performing Teachers: Final Results from a Multisite Randomized Experiment. NCEE 2014-4004

ERIC Educational Resources Information Center

Glazerman, Steven; Protik, Ali; Teh, Bing-ru; Bruch, Julie; Max, Jeffrey

2013-01-01

One way to improve struggling schools' access to effective teachers is to use selective transfer incentives. Such incentives offer bonuses for the highest-performing teachers to move into schools serving the most disadvantaged students. In this report, we provide evidence from a randomized experiment that tested whether such a policy intervention…

Voluntary, Randomized, Student Drug-Testing: Impact in a Rural, Low-Income, Community

ERIC Educational Resources Information Center

Barrington, Kyle D.

2008-01-01

Illegal drug use and abuse by the nation's secondary school students is a continuing public health issue and this is especially true for students living in rural, low-income areas where access to intervention and treatment services is often limited. To address this issue, some school districts have implemented voluntary, randomized, student …

Post-coma persons with extensive multiple disabilities use microswitch technology to access selected stimulus events or operate a radio device.

PubMed

Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Sigafoos, Jeff; Alberti, Gloria; Oliva, Doretta; Megna, Gianfranco; Iliceto, Carla; Damiani, Sabino; Ricci, Irene; Spica, Antonella

2011-01-01

The present two studies extended research evidence on the use of microswitch technology by post-coma persons with multiple disabilities. Specifically, Study I examined whether three adults with a diagnosis of minimally conscious state and multiple disabilities could use microswitches as tools to access brief, selected stimulus events. Study II assessed whether an adult, who had emerged from a minimally conscious state but was affected by multiple disabilities, could manage the use of a radio device via a microswitch-aided program. Results showed that the participants of Study I had a significant increase of microswitch responding during the intervention phases. The participant of Study II learned to change radio stations and seemed to spend different amounts of session time on the different stations available (suggesting preferences among the programs characterizing them). The importance of microswitch technology for assisting post-coma persons with multiple disabilities to positively engage with their environment was discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

High-speed, random-access fluorescence microscopy: I. High-resolution optical recording with voltage-sensitive dyes and ion indicators.

PubMed

Bullen, A; Patel, S S; Saggau, P

1997-07-01

The design and implementation of a high-speed, random-access, laser-scanning fluorescence microscope configured to record fast physiological signals from small neuronal structures with high spatiotemporal resolution is presented. The laser-scanning capability of this nonimaging microscope is provided by two orthogonal acousto-optic deflectors under computer control. Each scanning point can be randomly accessed and has a positioning time of 3-5 microseconds. Sampling time is also computer-controlled and can be varied to maximize the signal-to-noise ratio. Acquisition rates up to 200k samples/s at 16-bit digitizing resolution are possible. The spatial resolution of this instrument is determined by the minimal spot size at the level of the preparation (i.e., 2-7 microns). Scanning points are selected interactively from a reference image collected with differential interference contrast optics and a video camera. Frame rates up to 5 kHz are easily attainable. Intrinsic variations in laser light intensity and scanning spot brightness are overcome by an on-line signal-processing scheme. Representative records obtained with this instrument by using voltage-sensitive dyes and calcium indicators demonstrate the ability to make fast, high-fidelity measurements of membrane potential and intracellular calcium at high spatial resolution (2 microns) without any temporal averaging.