ANALYSIS OF FUZZY QUEUES: PARAMETRIC PROGRAMMING APPROACH BASED ON RANDOMNESS - FUZZINESS CONSISTENCY PRINCIPLE

OpenAIRE

Dhruba Das; Hemanta K. Baruah

2015-01-01

In this article, based on Zadeh’s extension principle we have apply the parametric programming approach to construct the membership functions of the performance measures when the interarrival time and the service time are fuzzy numbers based on the Baruah’s Randomness- Fuzziness Consistency Principle. The Randomness-Fuzziness Consistency Principle leads to defining a normal law of fuzziness using two different laws of randomness. In this article, two fuzzy queues FM...

Error evaluation method for material accountancy measurement. Evaluation of random and systematic errors based on material accountancy data

International Nuclear Information System (INIS)

Nidaira, Kazuo

2008-01-01

International Target Values (ITV) shows random and systematic measurement uncertainty components as a reference for routinely achievable measurement quality in the accountancy measurement. The measurement uncertainty, called error henceforth, needs to be periodically evaluated and checked against ITV for consistency as the error varies according to measurement methods, instruments, operators, certified reference samples, frequency of calibration, and so on. In the paper an error evaluation method was developed with focuses on (1) Specifying clearly error calculation model, (2) Getting always positive random and systematic error variances, (3) Obtaining probability density distribution of an error variance and (4) Confirming the evaluation method by simulation. In addition the method was demonstrated by applying real data. (author)

Random walks in the quarter-plane: invariant measures and performance bounds

NARCIS (Netherlands)

Chen, Y.

2015-01-01

This monograph focuses on random walks in the quarter-plane. Such random walks are frequently used to model queueing systems and the invariant measure of a random walk is of major importance in studying the performance of these systems. In special cases the invariant measure of a random walk can be

Pseudo-random number generator based on asymptotic deterministic randomness

Science.gov (United States)

Wang, Kai; Pei, Wenjiang; Xia, Haishan; Cheung, Yiu-ming

2008-06-01

A novel approach to generate the pseudorandom-bit sequence from the asymptotic deterministic randomness system is proposed in this Letter. We study the characteristic of multi-value correspondence of the asymptotic deterministic randomness constructed by the piecewise linear map and the noninvertible nonlinearity transform, and then give the discretized systems in the finite digitized state space. The statistic characteristics of the asymptotic deterministic randomness are investigated numerically, such as stationary probability density function and random-like behavior. Furthermore, we analyze the dynamics of the symbolic sequence. Both theoretical and experimental results show that the symbolic sequence of the asymptotic deterministic randomness possesses very good cryptographic properties, which improve the security of chaos based PRBGs and increase the resistance against entropy attacks and symbolic dynamics attacks.

Pseudo-random number generator based on asymptotic deterministic randomness

International Nuclear Information System (INIS)

Wang Kai; Pei Wenjiang; Xia Haishan; Cheung Yiuming

2008-01-01

A novel approach to generate the pseudorandom-bit sequence from the asymptotic deterministic randomness system is proposed in this Letter. We study the characteristic of multi-value correspondence of the asymptotic deterministic randomness constructed by the piecewise linear map and the noninvertible nonlinearity transform, and then give the discretized systems in the finite digitized state space. The statistic characteristics of the asymptotic deterministic randomness are investigated numerically, such as stationary probability density function and random-like behavior. Furthermore, we analyze the dynamics of the symbolic sequence. Both theoretical and experimental results show that the symbolic sequence of the asymptotic deterministic randomness possesses very good cryptographic properties, which improve the security of chaos based PRBGs and increase the resistance against entropy attacks and symbolic dynamics attacks

Frequency characteristic measurement of a fiber optic gyroscope using a correlation spectrum analysis method based on a pseudo-random sequence

International Nuclear Information System (INIS)

Li, Yang; Chen, Xingfan; Liu, Cheng

2015-01-01

The frequency characteristic is an important indicator of a system’s dynamic performance. The identification of a fiber optic gyroscope (FOG)’s frequency characteristic using a correlation spectrum analysis method based on a pseudo-random sequence is proposed. Taking the angle vibrator as the source of the test rotation stimulation and a pseudo-random sequence as the test signal, the frequency characteristic of a FOG is calculated according to the power spectral density of the rotation rate signal and the cross-power spectral density of the FOG’s output signal and rotation rate signal. A theoretical simulation is done to confirm the validity of this method. An experiment system is built and the test results indicate that the measurement error of the normalized amplitude–frequency response is less than 0.01, that the error of the phase–frequency response is less than 0.3 rad, and the overall measurement accuracy is superior to the traditional frequency-sweep method. By using this method, the FOG’s amplitude–frequency response and phase–frequency response can be measured simultaneously, quickly, accurately, and with a high frequency resolution. The described method meets the requirements of engineering applications. (paper)

Reheating-volume measure for random-walk inflation

International Nuclear Information System (INIS)

Winitzki, Sergei

2008-01-01

The recently proposed 'reheating-volume' (RV) measure promises to solve the long-standing problem of extracting probabilistic predictions from cosmological multiverse scenarios involving eternal inflation. I give a detailed description of the new measure and its applications to generic models of eternal inflation of random-walk type. For those models I derive a general formula for RV-regulated probability distributions that is suitable for numerical computations. I show that the results of the RV cutoff in random-walk type models are always gauge invariant and independent of the initial conditions at the beginning of inflation. In a toy model where equal-time cutoffs lead to the 'youngness paradox', the RV cutoff yields unbiased results that are distinct from previously proposed measures.

Quantum authentication based on the randomness of measurement bases in BB84

International Nuclear Information System (INIS)

Dang Minh Dung; Bellot, P.; Alleaume, R.

2005-01-01

Full text: The establishment of a secret key between two legitimate end points of a communication link, let us name them Alice and Bob, using Quantum key distribution (QKD) is unconditionally secure thanks to Quantum Physics laws.However, the various QKD protocols do not intend to provide the authentication of the end points: Alice cannot be sure that she is communicating with Bob and reciprocally. Therefore, these protocols are subjects to various attacks. The most obvious attack is the man-in-the-middle attack in which an eavesdropper, let us name her Eve, stands in the middle of the communication link. Alice communicates with Eve meanwhile she thinks she communicate with Bob. And Bob communicates with Eve meanwhile he thinks he is communicating with Alice. Eve, acting as a relay, can read all the communications between Alice and Bob and retransmit them. To prevent this kind of attack, the solution is to authenticate the two end points of the communication link. One solution is that Alice and Bob share an authentication key prior to the communication. In order to improve the security, Alice and Bob must share a set of authentication one-time keys. One-time key means that the key has to be used only once because each time a key is used, the eavesdropper Eve can gain a few information on the key. Re-using the same key many times would finally reveal the key to Eve. However, Eve can simulate many times the authentication process with Alice. Each time Eve simulates the authentication process, one of the pre-positioned keys is depleted leading to the exhaustion of the set of pre-positioned keys. This type of attack is named Denial of Service attack. In this work, we propose to use the randomness of the measurement bases in BB84 to build an authentication scheme based on the existence of a prepositioned authentication key. This authentication scheme can be used with BB84 but also with any other Quantum Key Distribution protocols. It is protected against the Denial of

Mindfulness-based stress reduction for residents: A randomized controlled trial

NARCIS (Netherlands)

Verweij, H.; Ravesteijn, H.J. van; Hooff, M.L.M. van; Lagro-Janssen, A.L.M.; Speckens, A.E.M.

2018-01-01

Background: Burnout is highly prevalent in residents. No randomized controlled trials have been conducted measuring the effects of Mindfulness-Based Stress Reduction (MBSR) on burnout in residents. Objective: To determine the effectiveness of MBSR in reducing burnout in residents. Design: A

An AES chip with DPA resistance using hardware-based random order execution

International Nuclear Information System (INIS)

Yu Bo; Li Xiangyu; Chen Cong; Sun Yihe; Wu Liji; Zhang Xiangmin

2012-01-01

This paper presents an AES (advanced encryption standard) chip that combats differential power analysis (DPA) side-channel attack through hardware-based random order execution. Both decryption and encryption procedures of an AES are implemented on the chip. A fine-grained dataflow architecture is proposed, which dynamically exploits intrinsic byte-level independence in the algorithm. A novel circuit called an HMF (Hold-Match-Fetch) unit is proposed for random control, which randomly sets execution orders for concurrent operations. The AES chip was manufactured in SMIC 0.18 μm technology. The average energy for encrypting one group of plain texts (128 bits secrete keys) is 19 nJ. The core area is 0.43 mm 2 . A sophisticated experimental setup was built to test the DPA resistance. Measurement-based experimental results show that one byte of a secret key cannot be disclosed from our chip under random mode after 64000 power traces were used in the DPA attack. Compared with the corresponding fixed order execution, the hardware based random order execution is improved by at least 21 times the DPA resistance. (semiconductor integrated circuits)

An AES chip with DPA resistance using hardware-based random order execution

Science.gov (United States)

Bo, Yu; Xiangyu, Li; Cong, Chen; Yihe, Sun; Liji, Wu; Xiangmin, Zhang

2012-06-01

This paper presents an AES (advanced encryption standard) chip that combats differential power analysis (DPA) side-channel attack through hardware-based random order execution. Both decryption and encryption procedures of an AES are implemented on the chip. A fine-grained dataflow architecture is proposed, which dynamically exploits intrinsic byte-level independence in the algorithm. A novel circuit called an HMF (Hold-Match-Fetch) unit is proposed for random control, which randomly sets execution orders for concurrent operations. The AES chip was manufactured in SMIC 0.18 μm technology. The average energy for encrypting one group of plain texts (128 bits secrete keys) is 19 nJ. The core area is 0.43 mm2. A sophisticated experimental setup was built to test the DPA resistance. Measurement-based experimental results show that one byte of a secret key cannot be disclosed from our chip under random mode after 64000 power traces were used in the DPA attack. Compared with the corresponding fixed order execution, the hardware based random order execution is improved by at least 21 times the DPA resistance.

A new reliability measure based on specified minimum distances before the locations of random variables in a finite interval

International Nuclear Information System (INIS)

Todinov, M.T.

2004-01-01

A new reliability measure is proposed and equations are derived which determine the probability of existence of a specified set of minimum gaps between random variables following a homogeneous Poisson process in a finite interval. Using the derived equations, a method is proposed for specifying the upper bound of the random variables' number density which guarantees that the probability of clustering of two or more random variables in a finite interval remains below a maximum acceptable level. It is demonstrated that even for moderate number densities the probability of clustering is substantial and should not be neglected in reliability calculations. In the important special case where the random variables are failure times, models have been proposed for determining the upper bound of the hazard rate which guarantees a set of minimum failure-free operating intervals before the random failures, with a specified probability. A model has also been proposed for determining the upper bound of the hazard rate which guarantees a minimum availability target. Using the models proposed, a new strategy, models and reliability tools have been developed for setting quantitative reliability requirements which consist of determining the intersection of the hazard rate envelopes (hazard rate upper bounds) which deliver a minimum failure-free operating period before random failures, a risk of premature failure below a maximum acceptable level and a minimum required availability. It is demonstrated that setting reliability requirements solely based on an availability target does not necessarily mean a low risk of premature failure. Even at a high availability level, the probability of premature failure can be substantial. For industries characterised by a high cost of failure, the reliability requirements should involve a hazard rate envelope limiting the risk of failure below a maximum acceptable level

Effectiveness of Wii-based rehabilitation in stroke: A randomized controlled study

OpenAIRE

Ayça Utkan Karasu; Elif Balevi Batur; Gülçin Kaymak Karataş

2018-01-01

Objective: To investigate the efficacy of Nintendo Wii Fit®-based balance rehabilitation as an adjunc-tive therapy to conventional rehabilitation in stroke patients. Methods: During the study period, 70 stroke patients were evaluated. Of these, 23 who met the study criteria were randomly assigned to either the experimental group (n = 12) or the control group (n = 11) by block randomization. Primary outcome measures were Berg Balance Scale, Functional Reach Test, Postural Asses...

The Random Walk Model Based on Bipartite Network

Directory of Open Access Journals (Sweden)

Zhang Man-Dun

2016-01-01

Full Text Available With the continuing development of the electronic commerce and growth of network information, there is a growing possibility for citizens to be confused by the information. Though the traditional technology of information retrieval have the ability to relieve the overload of information in some extent, it can not offer a targeted personality service based on user’s interests and activities. In this context, the recommendation algorithm arose. In this paper, on the basis of conventional recommendation, we studied the scheme of random walk based on bipartite network and the application of it. We put forward a similarity measurement based on implicit feedback. In this method, a uneven character vector is imported(the weight of item in the system. We put forward a improved random walk pattern which make use of partial or incomplete neighbor information to create recommendation information. In the end, there is an experiment in the real data set, the recommendation accuracy and practicality are improved. We promise the reality of the result of the experiment

Random measures, theory and applications

CERN Document Server

Kallenberg, Olav

2017-01-01

Offering the first comprehensive treatment of the theory of random measures, this book has a very broad scope, ranging from basic properties of Poisson and related processes to the modern theories of convergence, stationarity, Palm measures, conditioning, and compensation. The three large final chapters focus on applications within the areas of stochastic geometry, excursion theory, and branching processes. Although this theory plays a fundamental role in most areas of modern probability, much of it, including the most basic material, has previously been available only in scores of journal articles. The book is primarily directed towards researchers and advanced graduate students in stochastic processes and related areas.

What Randomized Benchmarking Actually Measures

International Nuclear Information System (INIS)

Proctor, Timothy; Rudinger, Kenneth; Young, Kevin; Sarovar, Mohan; Blume-Kohout, Robin

2017-01-01

Randomized benchmarking (RB) is widely used to measure an error rate of a set of quantum gates, by performing random circuits that would do nothing if the gates were perfect. In the limit of no finite-sampling error, the exponential decay rate of the observable survival probabilities, versus circuit length, yields a single error metric r. For Clifford gates with arbitrary small errors described by process matrices, r was believed to reliably correspond to the mean, over all Clifford gates, of the average gate infidelity between the imperfect gates and their ideal counterparts. We show that this quantity is not a well-defined property of a physical gate set. It depends on the representations used for the imperfect and ideal gates, and the variant typically computed in the literature can differ from r by orders of magnitude. We present new theories of the RB decay that are accurate for all small errors describable by process matrices, and show that the RB decay curve is a simple exponential for all such errors. Here, these theories allow explicit computation of the error rate that RB measures (r), but as far as we can tell it does not correspond to the infidelity of a physically allowed (completely positive) representation of the imperfect gates.

ANALYSIS OF FUZZY QUEUES: PARAMETRIC PROGRAMMING APPROACH BASED ON RANDOMNESS - FUZZINESS CONSISTENCY PRINCIPLE

Directory of Open Access Journals (Sweden)

Dhruba Das

2015-04-01

Full Text Available In this article, based on Zadeh’s extension principle we have apply the parametric programming approach to construct the membership functions of the performance measures when the interarrival time and the service time are fuzzy numbers based on the Baruah’s Randomness- Fuzziness Consistency Principle. The Randomness-Fuzziness Consistency Principle leads to defining a normal law of fuzziness using two different laws of randomness. In this article, two fuzzy queues FM/M/1 and M/FM/1 has been studied and constructed their membership functions of the system characteristics based on the aforesaid principle. The former represents a queue with fuzzy exponential arrivals and exponential service rate while the latter represents a queue with exponential arrival rate and fuzzy exponential service rate.

RandomSpot: A web-based tool for systematic random sampling of virtual slides.

Science.gov (United States)

Wright, Alexander I; Grabsch, Heike I; Treanor, Darren E

2015-01-01

This paper describes work presented at the Nordic Symposium on Digital Pathology 2014, Linköping, Sweden. Systematic random sampling (SRS) is a stereological tool, which provides a framework to quickly build an accurate estimation of the distribution of objects or classes within an image, whilst minimizing the number of observations required. RandomSpot is a web-based tool for SRS in stereology, which systematically places equidistant points within a given region of interest on a virtual slide. Each point can then be visually inspected by a pathologist in order to generate an unbiased sample of the distribution of classes within the tissue. Further measurements can then be derived from the distribution, such as the ratio of tumor to stroma. RandomSpot replicates the fundamental principle of traditional light microscope grid-shaped graticules, with the added benefits associated with virtual slides, such as facilitated collaboration and automated navigation between points. Once the sample points have been added to the region(s) of interest, users can download the annotations and view them locally using their virtual slide viewing software. Since its introduction, RandomSpot has been used extensively for international collaborative projects, clinical trials and independent research projects. So far, the system has been used to generate over 21,000 sample sets, and has been used to generate data for use in multiple publications, identifying significant new prognostic markers in colorectal, upper gastro-intestinal and breast cancer. Data generated using RandomSpot also has significant value for training image analysis algorithms using sample point coordinates and pathologist classifications.

Variances as order parameter and complexity measure for random Boolean networks

International Nuclear Information System (INIS)

Luque, Bartolo; Ballesteros, Fernando J; Fernandez, Manuel

2005-01-01

Several order parameters have been considered to predict and characterize the transition between ordered and disordered phases in random Boolean networks, such as the Hamming distance between replicas or the stable core, which have been successfully used. In this work, we propose a natural and clear new order parameter: the temporal variance. We compute its value analytically and compare it with the results of numerical experiments. Finally, we propose a complexity measure based on the compromise between temporal and spatial variances. This new order parameter and its related complexity measure can be easily applied to other complex systems

Variances as order parameter and complexity measure for random Boolean networks

Energy Technology Data Exchange (ETDEWEB)

Luque, Bartolo [Departamento de Matematica Aplicada y EstadIstica, Escuela Superior de Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain); Ballesteros, Fernando J [Observatori Astronomic, Universitat de Valencia, Ed. Instituts d' Investigacio, Pol. La Coma s/n, E-46980 Paterna, Valencia (Spain); Fernandez, Manuel [Departamento de Matematica Aplicada y EstadIstica, Escuela Superior de Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain)

2005-02-04

Several order parameters have been considered to predict and characterize the transition between ordered and disordered phases in random Boolean networks, such as the Hamming distance between replicas or the stable core, which have been successfully used. In this work, we propose a natural and clear new order parameter: the temporal variance. We compute its value analytically and compare it with the results of numerical experiments. Finally, we propose a complexity measure based on the compromise between temporal and spatial variances. This new order parameter and its related complexity measure can be easily applied to other complex systems.

An efficient binomial model-based measure for sequence comparison and its application.

Science.gov (United States)

Liu, Xiaoqing; Dai, Qi; Li, Lihua; He, Zerong

2011-04-01

Sequence comparison is one of the major tasks in bioinformatics, which could serve as evidence of structural and functional conservation, as well as of evolutionary relations. There are several similarity/dissimilarity measures for sequence comparison, but challenges remains. This paper presented a binomial model-based measure to analyze biological sequences. With help of a random indicator, the occurrence of a word at any position of sequence can be regarded as a random Bernoulli variable, and the distribution of a sum of the word occurrence is well known to be a binomial one. By using a recursive formula, we computed the binomial probability of the word count and proposed a binomial model-based measure based on the relative entropy. The proposed measure was tested by extensive experiments including classification of HEV genotypes and phylogenetic analysis, and further compared with alignment-based and alignment-free measures. The results demonstrate that the proposed measure based on binomial model is more efficient.

DNA-based random number generation in security circuitry.

Science.gov (United States)

Gearheart, Christy M; Arazi, Benjamin; Rouchka, Eric C

2010-06-01

DNA-based circuit design is an area of research in which traditional silicon-based technologies are replaced by naturally occurring phenomena taken from biochemistry and molecular biology. This research focuses on further developing DNA-based methodologies to mimic digital data manipulation. While exhibiting fundamental principles, this work was done in conjunction with the vision that DNA-based circuitry, when the technology matures, will form the basis for a tamper-proof security module, revolutionizing the meaning and concept of tamper-proofing and possibly preventing it altogether based on accurate scientific observations. A paramount part of such a solution would be self-generation of random numbers. A novel prototype schema employs solid phase synthesis of oligonucleotides for random construction of DNA sequences; temporary storage and retrieval is achieved through plasmid vectors. A discussion of how to evaluate sequence randomness is included, as well as how these techniques are applied to a simulation of the random number generation circuitry. Simulation results show generated sequences successfully pass three selected NIST random number generation tests specified for security applications.

Community-based peer-led diabetes self-management: a randomized trial.

Science.gov (United States)

Lorig, Kate; Ritter, Philip L; Villa, Frank J; Armas, Jean

2009-01-01

The purpose of this study is to determine the effectiveness of a community-based diabetes self-management program comparing treatment participants to a randomized usual-care control group at 6 months. A total of 345 adults with type 2 diabetes but no criteria for high A1C were randomized to a usual-care control group or 6-week community-based, peer-led diabetes self-management program (DSMP). Randomized participants were compared at 6 months. The DSMP intervention participants were followed for an additional 6 months (12 months total). A1C and body mass index were measured at baseline, 6 months, and 12 months. All other data were collected by self-administered questionnaires. At 6 months, DSMP participants did not demonstrate improvements in A1C as compared with controls. Baseline A1C was much lower than in similar trials. Participants did have significant improvements in depression, symptoms of hypoglycemia, communication with physicians, healthy eating, and reading food labels (P < .01). They also had significant improvements in patient activation and self-efficacy. At 12 months, DSMP intervention participants continued to demonstrate improvements in depression, communication with physicians, healthy eating, patient activation, and self-efficacy (P < .01). There were no significant changes in utilization measures. These findings suggest that people with diabetes without elevated A1C can benefit from a community-based, peer-led diabetes program. Given the large number of people with diabetes and lack of low-cost diabetes education, the DSMP deserves consideration for implementation.

Design and usability evaluation of user-centered and visual-based aids for dietary food measurement on mobile devices in a randomized controlled trial.

Science.gov (United States)

Liu, Ying-Chieh; Chen, Chien-Hung; Lee, Chien-Wei; Lin, Yu-Sheng; Chen, Hsin-Yun; Yeh, Jou-Yin; Chiu, Sherry Yueh-Hsia

2016-12-01

We designed and developed two interactive apps interfaces for dietary food measurements on mobile devices. The user-centered designs of both the IPI (interactive photo interface) and the SBI (sketching-based interface) were evaluated. Four types of outcomes were assessed to evaluate the usability of mobile devices for dietary measurements, including accuracy, absolute weight differences, and the response time to determine the efficacy of food measurements. The IPI presented users with images of pre-determined portion sizes of a specific food and allowed users to scan and then select the most representative image matching the food that they were measuring. The SBI required users to relate the food shape to a readily available comparator (e.g., credit card) and scribble to shade in the appropriate area. A randomized controlled trial was conducted to evaluate their usability. A total of 108 participants were randomly assigned into the following three groups: the IPI (n=36) and SBI (n=38) experimental groups and the traditional life-size photo (TLP) group as the control. A total of 18 types of food items with 3-4 different weights were randomly selected for assessment by each type. The independent Chi-square test and t-test were performed for the dichotomous and continuous variable analyses, respectively. The total accuracy rates were 66.98%, 44.15%, and 72.06% for the IPI, SBI, and TLP, respectively. No significant difference was observed between the IPI and TLP, regardless of the accuracy proportion or weight differences. The SBI accuracy rates were significantly lower than the IPI and TLP accuracy rates, especially for several spooned, square cube, and sliced pie food items. The time needed to complete the operation assessment by the user was significantly lower for the IPI than for the SBI. Our study corroborates that the user-centered visual-based design of the IPI on a mobile device is comparable the TLP in terms of the usability for dietary food measurements

Classical and nonclassical randomness in quantum measurements

International Nuclear Information System (INIS)

Farenick, Douglas; Plosker, Sarah; Smith, Jerrod

2011-01-01

The space POVM H (X) of positive operator-valued probability measures on the Borel sets of a compact (or even locally compact) Hausdorff space X with values in B(H), the algebra of linear operators acting on a d-dimensional Hilbert space H, is studied from the perspectives of classical and nonclassical convexity through a transform Γ that associates any positive operator-valued measure ν with a certain completely positive linear map Γ(ν) of the homogeneous C*-algebra C(X) x B(H) into B(H). This association is achieved by using an operator-valued integral in which nonclassical random variables (that is, operator-valued functions) are integrated with respect to positive operator-valued measures and which has the feature that the integral of a random quantum effect is itself a quantum effect. A left inverse Ω for Γ yields an integral representation, along the lines of the classical Riesz representation theorem for linear functionals on C(X), of certain (but not all) unital completely positive linear maps φ:C(X) x B(H)→B(H). The extremal and C*-extremal points of POVM H (X) are determined.

The behaviour of random forest permutation-based variable importance measures under predictor correlation.

Science.gov (United States)

Nicodemus, Kristin K; Malley, James D; Strobl, Carolin; Ziegler, Andreas

2010-02-27

Random forests (RF) have been increasingly used in applications such as genome-wide association and microarray studies where predictor correlation is frequently observed. Recent works on permutation-based variable importance measures (VIMs) used in RF have come to apparently contradictory conclusions. We present an extended simulation study to synthesize results. In the case when both predictor correlation was present and predictors were associated with the outcome (HA), the unconditional RF VIM attributed a higher share of importance to correlated predictors, while under the null hypothesis that no predictors are associated with the outcome (H0) the unconditional RF VIM was unbiased. Conditional VIMs showed a decrease in VIM values for correlated predictors versus the unconditional VIMs under HA and was unbiased under H0. Scaled VIMs were clearly biased under HA and H0. Unconditional unscaled VIMs are a computationally tractable choice for large datasets and are unbiased under the null hypothesis. Whether the observed increased VIMs for correlated predictors may be considered a "bias" - because they do not directly reflect the coefficients in the generating model - or if it is a beneficial attribute of these VIMs is dependent on the application. For example, in genetic association studies, where correlation between markers may help to localize the functionally relevant variant, the increased importance of correlated predictors may be an advantage. On the other hand, we show examples where this increased importance may result in spurious signals.

Random measurement error: Why worry? An example of cardiovascular risk factors.

Science.gov (United States)

Brakenhoff, Timo B; van Smeden, Maarten; Visseren, Frank L J; Groenwold, Rolf H H

2018-01-01

With the increased use of data not originally recorded for research, such as routine care data (or 'big data'), measurement error is bound to become an increasingly relevant problem in medical research. A common view among medical researchers on the influence of random measurement error (i.e. classical measurement error) is that its presence leads to some degree of systematic underestimation of studied exposure-outcome relations (i.e. attenuation of the effect estimate). For the common situation where the analysis involves at least one exposure and one confounder, we demonstrate that the direction of effect of random measurement error on the estimated exposure-outcome relations can be difficult to anticipate. Using three example studies on cardiovascular risk factors, we illustrate that random measurement error in the exposure and/or confounder can lead to underestimation as well as overestimation of exposure-outcome relations. We therefore advise medical researchers to refrain from making claims about the direction of effect of measurement error in their manuscripts, unless the appropriate inferential tools are used to study or alleviate the impact of measurement error from the analysis.

Online evolution reconstruction from a single measurement record with random time intervals for quantum communication

Science.gov (United States)

Zhou, Hua; Su, Yang; Wang, Rong; Zhu, Yong; Shen, Huiping; Pu, Tao; Wu, Chuanxin; Zhao, Jiyong; Zhang, Baofu; Xu, Zhiyong

2017-10-01

Online reconstruction of a time-variant quantum state from the encoding/decoding results of quantum communication is addressed by developing a method of evolution reconstruction from a single measurement record with random time intervals. A time-variant two-dimensional state is reconstructed on the basis of recovering its expectation value functions of three nonorthogonal projectors from a random single measurement record, which is composed from the discarded qubits of the six-state protocol. The simulated results prove that our method is robust to typical metro quantum channels. Our work extends the Fourier-based method of evolution reconstruction from the version for a regular single measurement record with equal time intervals to a unified one, which can be applied to arbitrary single measurement records. The proposed protocol of evolution reconstruction runs concurrently with the one of quantum communication, which can facilitate the online quantum tomography.

Permutation Entropy for Random Binary Sequences

Directory of Open Access Journals (Sweden)

Lingfeng Liu

2015-12-01

Full Text Available In this paper, we generalize the permutation entropy (PE measure to binary sequences, which is based on Shannon’s entropy, and theoretically analyze this measure for random binary sequences. We deduce the theoretical value of PE for random binary sequences, which can be used to measure the randomness of binary sequences. We also reveal the relationship between this PE measure with other randomness measures, such as Shannon’s entropy and Lempel–Ziv complexity. The results show that PE is consistent with these two measures. Furthermore, we use PE as one of the randomness measures to evaluate the randomness of chaotic binary sequences.

Novel pseudo-random number generator based on quantum random walks

Science.gov (United States)

Yang, Yu-Guang; Zhao, Qian-Qian

2016-02-01

In this paper, we investigate the potential application of quantum computation for constructing pseudo-random number generators (PRNGs) and further construct a novel PRNG based on quantum random walks (QRWs), a famous quantum computation model. The PRNG merely relies on the equations used in the QRWs, and thus the generation algorithm is simple and the computation speed is fast. The proposed PRNG is subjected to statistical tests such as NIST and successfully passed the test. Compared with the representative PRNG based on quantum chaotic maps (QCM), the present QRWs-based PRNG has some advantages such as better statistical complexity and recurrence. For example, the normalized Shannon entropy and the statistical complexity of the QRWs-based PRNG are 0.999699456771172 and 1.799961178212329e-04 respectively given the number of 8 bits-words, say, 16Mbits. By contrast, the corresponding values of the QCM-based PRNG are 0.999448131481064 and 3.701210794388818e-04 respectively. Thus the statistical complexity and the normalized entropy of the QRWs-based PRNG are closer to 0 and 1 respectively than those of the QCM-based PRNG when the number of words of the analyzed sequence increases. It provides a new clue to construct PRNGs and also extends the applications of quantum computation.

Novel pseudo-random number generator based on quantum random walks.

Science.gov (United States)

Yang, Yu-Guang; Zhao, Qian-Qian

2016-02-04

In this paper, we investigate the potential application of quantum computation for constructing pseudo-random number generators (PRNGs) and further construct a novel PRNG based on quantum random walks (QRWs), a famous quantum computation model. The PRNG merely relies on the equations used in the QRWs, and thus the generation algorithm is simple and the computation speed is fast. The proposed PRNG is subjected to statistical tests such as NIST and successfully passed the test. Compared with the representative PRNG based on quantum chaotic maps (QCM), the present QRWs-based PRNG has some advantages such as better statistical complexity and recurrence. For example, the normalized Shannon entropy and the statistical complexity of the QRWs-based PRNG are 0.999699456771172 and 1.799961178212329e-04 respectively given the number of 8 bits-words, say, 16Mbits. By contrast, the corresponding values of the QCM-based PRNG are 0.999448131481064 and 3.701210794388818e-04 respectively. Thus the statistical complexity and the normalized entropy of the QRWs-based PRNG are closer to 0 and 1 respectively than those of the QCM-based PRNG when the number of words of the analyzed sequence increases. It provides a new clue to construct PRNGs and also extends the applications of quantum computation.

Nurse-Moderated Internet-Based Support for New Mothers: Non-Inferiority, Randomized Controlled Trial.

Science.gov (United States)

Sawyer, Michael G; Reece, Christy E; Bowering, Kerrie; Jeffs, Debra; Sawyer, Alyssa C P; Mittinty, Murthy; Lynch, John W

2017-07-24

Internet-based interventions moderated by community nurses have the potential to improve support offered to new mothers, many of whom now make extensive use of the Internet to obtain information about infant care. However, evidence from population-based randomized controlled trials is lacking. The aim of this study was to test the non-inferiority of outcomes for mothers and infants who received a clinic-based postnatal health check plus nurse-moderated, Internet-based group support when infants were aged 1-7 months as compared with outcomes for those who received standard care consisting of postnatal home-based support provided by a community nurse. The design of the study was a pragmatic, preference, non-inferiority randomized control trial. Participants were recruited from mothers contacted for their postnatal health check, which is offered to all mothers in South Australia. Mothers were assigned either (1) on the basis of their preference to clinic+Internet or home-based support groups (n=328), or (2) randomly assigned to clinic+Internet or home-based groups if they declared no strong preference (n=491). The overall response rate was 44.8% (819/1827). The primary outcome was parenting self-competence, as measured by the Parenting Stress Index (PSI) Competence subscale, and the Karitane Parenting Confidence Scale scores. Secondary outcome measures included PSI Isolation, Interpersonal Support Evaluation List-Short Form, Maternal Support Scale, Ages and Stages Questionnaire-Social-Emotional and MacArthur Communicative Development Inventory (MCDI) scores. Assessments were completed offline via self-assessment questionnaires at enrolment (mean child age=4.1 weeks, SD 1.3) and again when infants were aged 9, 15, and 21 months. Generalized estimating equations adjusting for post-randomization baseline imbalances showed that differences in outcomes between mothers in the clinic+Internet and home-based support groups did not exceed the pre-specified margin of

Algorithmic randomness, physical entropy, measurements, and the second law

International Nuclear Information System (INIS)

Zurek, W.H.

1989-01-01

Algorithmic information content is equal to the size -- in the number of bits -- of the shortest program for a universal Turing machine which can reproduce a state of a physical system. In contrast to the statistical Boltzmann-Gibbs-Shannon entropy, which measures ignorance, the algorithmic information content is a measure of the available information. It is defined without a recourse to probabilities and can be regarded as a measure of randomness of a definite microstate. I suggest that the physical entropy S -- that is, the quantity which determines the amount of the work ΔW which can be extracted in the cyclic isothermal expansion process through the equation ΔW = k B TΔS -- is a sum of two contributions: the mission information measured by the usual statistical entropy and the known randomness measured by the algorithmic information content. The sum of these two contributions is a ''constant of motion'' in the process of a dissipation less measurement on an equilibrium ensemble. This conservation under a measurement, which can be traced back to the noiseless coding theorem of Shannon, is necessary to rule out existence of a successful Maxwell's demon. 17 refs., 3 figs

Random measurement error: Why worry? An example of cardiovascular risk factors.

Directory of Open Access Journals (Sweden)

Timo B Brakenhoff

Full Text Available With the increased use of data not originally recorded for research, such as routine care data (or 'big data', measurement error is bound to become an increasingly relevant problem in medical research. A common view among medical researchers on the influence of random measurement error (i.e. classical measurement error is that its presence leads to some degree of systematic underestimation of studied exposure-outcome relations (i.e. attenuation of the effect estimate. For the common situation where the analysis involves at least one exposure and one confounder, we demonstrate that the direction of effect of random measurement error on the estimated exposure-outcome relations can be difficult to anticipate. Using three example studies on cardiovascular risk factors, we illustrate that random measurement error in the exposure and/or confounder can lead to underestimation as well as overestimation of exposure-outcome relations. We therefore advise medical researchers to refrain from making claims about the direction of effect of measurement error in their manuscripts, unless the appropriate inferential tools are used to study or alleviate the impact of measurement error from the analysis.

Dipole location using SQUID based measurements: Application to magnetocardiography

Science.gov (United States)

Mariyappa, N.; Parasakthi, C.; Sengottuvel, S.; Gireesan, K.; Patel, Rajesh; Janawadkar, M. P.; Sundar, C. S.; Radhakrishnan, T. S.

2012-07-01

We report a method of inferring the dipole location using iterative nonlinear least square optimization based on Levenberg-Marquardt algorithm, wherein, we use different sets of pseudo-random numbers as initial parameter values. The method has been applied to (i) the simulated data representing the calculated magnetic field distribution produced by a point dipole placed at a known position, (ii) the experimental data from SQUID based measurements of the magnetic field distribution produced by a source coil carrying current, and (iii) the actual experimentally measured magnetocardiograms of human subjects using a SQUID based system.

Measuring symmetry, asymmetry and randomness in neural network connectivity.

Directory of Open Access Journals (Sweden)

Umberto Esposito

Full Text Available Cognitive functions are stored in the connectome, the wiring diagram of the brain, which exhibits non-random features, so-called motifs. In this work, we focus on bidirectional, symmetric motifs, i.e. two neurons that project to each other via connections of equal strength, and unidirectional, non-symmetric motifs, i.e. within a pair of neurons only one neuron projects to the other. We hypothesise that such motifs have been shaped via activity dependent synaptic plasticity processes. As a consequence, learning moves the distribution of the synaptic connections away from randomness. Our aim is to provide a global, macroscopic, single parameter characterisation of the statistical occurrence of bidirectional and unidirectional motifs. To this end we define a symmetry measure that does not require any a priori thresholding of the weights or knowledge of their maximal value. We calculate its mean and variance for random uniform or Gaussian distributions, which allows us to introduce a confidence measure of how significantly symmetric or asymmetric a specific configuration is, i.e. how likely it is that the configuration is the result of chance. We demonstrate the discriminatory power of our symmetry measure by inspecting the eigenvalues of different types of connectivity matrices. We show that a Gaussian weight distribution biases the connectivity motifs to more symmetric configurations than a uniform distribution and that introducing a random synaptic pruning, mimicking developmental regulation in synaptogenesis, biases the connectivity motifs to more asymmetric configurations, regardless of the distribution. We expect that our work will benefit the computational modelling community, by providing a systematic way to characterise symmetry and asymmetry in network structures. Further, our symmetry measure will be of use to electrophysiologists that investigate symmetry of network connectivity.

Measuring symmetry, asymmetry and randomness in neural network connectivity.

Science.gov (United States)

Esposito, Umberto; Giugliano, Michele; van Rossum, Mark; Vasilaki, Eleni

2014-01-01

Cognitive functions are stored in the connectome, the wiring diagram of the brain, which exhibits non-random features, so-called motifs. In this work, we focus on bidirectional, symmetric motifs, i.e. two neurons that project to each other via connections of equal strength, and unidirectional, non-symmetric motifs, i.e. within a pair of neurons only one neuron projects to the other. We hypothesise that such motifs have been shaped via activity dependent synaptic plasticity processes. As a consequence, learning moves the distribution of the synaptic connections away from randomness. Our aim is to provide a global, macroscopic, single parameter characterisation of the statistical occurrence of bidirectional and unidirectional motifs. To this end we define a symmetry measure that does not require any a priori thresholding of the weights or knowledge of their maximal value. We calculate its mean and variance for random uniform or Gaussian distributions, which allows us to introduce a confidence measure of how significantly symmetric or asymmetric a specific configuration is, i.e. how likely it is that the configuration is the result of chance. We demonstrate the discriminatory power of our symmetry measure by inspecting the eigenvalues of different types of connectivity matrices. We show that a Gaussian weight distribution biases the connectivity motifs to more symmetric configurations than a uniform distribution and that introducing a random synaptic pruning, mimicking developmental regulation in synaptogenesis, biases the connectivity motifs to more asymmetric configurations, regardless of the distribution. We expect that our work will benefit the computational modelling community, by providing a systematic way to characterise symmetry and asymmetry in network structures. Further, our symmetry measure will be of use to electrophysiologists that investigate symmetry of network connectivity.

Modeling and optimizing of the random atomic spin gyroscope drift based on the atomic spin gyroscope

Energy Technology Data Exchange (ETDEWEB)

Quan, Wei; Lv, Lin, E-mail: lvlinlch1990@163.com; Liu, Baiqi [School of Instrument Science and Opto-Electronics Engineering, Beihang University, Beijing 100191 (China)

2014-11-15

In order to improve the atom spin gyroscope's operational accuracy and compensate the random error caused by the nonlinear and weak-stability characteristic of the random atomic spin gyroscope (ASG) drift, the hybrid random drift error model based on autoregressive (AR) and genetic programming (GP) + genetic algorithm (GA) technique is established. The time series of random ASG drift is taken as the study object. The time series of random ASG drift is acquired by analyzing and preprocessing the measured data of ASG. The linear section model is established based on AR technique. After that, the nonlinear section model is built based on GP technique and GA is used to optimize the coefficients of the mathematic expression acquired by GP in order to obtain a more accurate model. The simulation result indicates that this hybrid model can effectively reflect the characteristics of the ASG's random drift. The square error of the ASG's random drift is reduced by 92.40%. Comparing with the AR technique and the GP + GA technique, the random drift is reduced by 9.34% and 5.06%, respectively. The hybrid modeling method can effectively compensate the ASG's random drift and improve the stability of the system.

Complexity-Based Measures Inform Effects of Tai Chi Training on Standing Postural Control: Cross-Sectional and Randomized Trial Studies.

Science.gov (United States)

Wayne, Peter M; Gow, Brian J; Costa, Madalena D; Peng, C-K; Lipsitz, Lewis A; Hausdorff, Jeffrey M; Davis, Roger B; Walsh, Jacquelyn N; Lough, Matthew; Novak, Vera; Yeh, Gloria Y; Ahn, Andrew C; Macklin, Eric A; Manor, Brad

2014-01-01

Diminished control of standing balance, traditionally indicated by greater postural sway magnitude and speed, is associated with falls in older adults. Tai Chi (TC) is a multisystem intervention that reduces fall risk, yet its impact on sway measures vary considerably. We hypothesized that TC improves the integrated function of multiple control systems influencing balance, quantifiable by the multi-scale "complexity" of postural sway fluctuations. To evaluate both traditional and complexity-based measures of sway to characterize the short- and potential long-term effects of TC training on postural control and the relationships between sway measures and physical function in healthy older adults. A cross-sectional comparison of standing postural sway in healthy TC-naïve and TC-expert (24.5±12 yrs experience) adults. TC-naïve participants then completed a 6-month, two-arm, wait-list randomized clinical trial of TC training. Postural sway was assessed before and after the training during standing on a force-plate with eyes-open (EO) and eyes-closed (EC). Anterior-posterior (AP) and medio-lateral (ML) sway speed, magnitude, and complexity (quantified by multiscale entropy) were calculated. Single-legged standing time and Timed-Up-and-Go tests characterized physical function. At baseline, compared to TC-naïve adults (n = 60, age 64.5±7.5 yrs), TC-experts (n = 27, age 62.8±7.5 yrs) exhibited greater complexity of sway in the AP EC (P = 0.023), ML EO (P<0.001), and ML EC (P<0.001) conditions. Traditional measures of sway speed and magnitude were not significantly lower among TC-experts. Intention-to-treat analyses indicated no significant effects of short-term TC training; however, increases in AP EC and ML EC complexity amongst those randomized to TC were positively correlated with practice hours (P = 0.044, P = 0.018). Long- and short-term TC training were positively associated with physical function. Multiscale entropy offers a complementary

Complexity-Based Measures Inform Effects of Tai Chi Training on Standing Postural Control: Cross-Sectional and Randomized Trial Studies.

Directory of Open Access Journals (Sweden)

Peter M Wayne

Full Text Available Diminished control of standing balance, traditionally indicated by greater postural sway magnitude and speed, is associated with falls in older adults. Tai Chi (TC is a multisystem intervention that reduces fall risk, yet its impact on sway measures vary considerably. We hypothesized that TC improves the integrated function of multiple control systems influencing balance, quantifiable by the multi-scale "complexity" of postural sway fluctuations.To evaluate both traditional and complexity-based measures of sway to characterize the short- and potential long-term effects of TC training on postural control and the relationships between sway measures and physical function in healthy older adults.A cross-sectional comparison of standing postural sway in healthy TC-naïve and TC-expert (24.5±12 yrs experience adults. TC-naïve participants then completed a 6-month, two-arm, wait-list randomized clinical trial of TC training. Postural sway was assessed before and after the training during standing on a force-plate with eyes-open (EO and eyes-closed (EC. Anterior-posterior (AP and medio-lateral (ML sway speed, magnitude, and complexity (quantified by multiscale entropy were calculated. Single-legged standing time and Timed-Up-and-Go tests characterized physical function.At baseline, compared to TC-naïve adults (n = 60, age 64.5±7.5 yrs, TC-experts (n = 27, age 62.8±7.5 yrs exhibited greater complexity of sway in the AP EC (P = 0.023, ML EO (P<0.001, and ML EC (P<0.001 conditions. Traditional measures of sway speed and magnitude were not significantly lower among TC-experts. Intention-to-treat analyses indicated no significant effects of short-term TC training; however, increases in AP EC and ML EC complexity amongst those randomized to TC were positively correlated with practice hours (P = 0.044, P = 0.018. Long- and short-term TC training were positively associated with physical function.Multiscale entropy offers a complementary

Random numbers from vacuum fluctuations

International Nuclear Information System (INIS)

Shi, Yicheng; Kurtsiefer, Christian; Chng, Brenda

2016-01-01

We implement a quantum random number generator based on a balanced homodyne measurement of vacuum fluctuations of the electromagnetic field. The digitized signal is directly processed with a fast randomness extraction scheme based on a linear feedback shift register. The random bit stream is continuously read in a computer at a rate of about 480 Mbit/s and passes an extended test suite for random numbers.

Random numbers from vacuum fluctuations

Energy Technology Data Exchange (ETDEWEB)

Shi, Yicheng; Kurtsiefer, Christian, E-mail: christian.kurtsiefer@gmail.com [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Center for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore); Chng, Brenda [Center for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore)

2016-07-25

We implement a quantum random number generator based on a balanced homodyne measurement of vacuum fluctuations of the electromagnetic field. The digitized signal is directly processed with a fast randomness extraction scheme based on a linear feedback shift register. The random bit stream is continuously read in a computer at a rate of about 480 Mbit/s and passes an extended test suite for random numbers.

A Maximin Approach for the Bi-criteria 0-1 Random Fuzzy Programming Problem Based on the Necessity Measure

International Nuclear Information System (INIS)

Hasuike, Takashi; Ishii, Hiroaki; Katagiri, Hideki

2009-01-01

This paper considers a bi-criteria general 0-1 random fuzzy programming problem based on the degree of necessity which include some previous 0-1 stochastic and fuzzy programming problems. The proposal problem is not well-defined due to including randomness and fuzziness. Therefore, by introducing chance constraint and fuzzy goals for objectives, and considering the maximization of the aspiration level for total profit and the degree of necessity that the objective function's value satisfies the fuzzy goal, the main problem is transformed into a deterministic equivalent problem. Furthermore, by using the assumption that each random variable is distributed according to a normal distribution, the problem is equivalently transformed into a basic 0-1 programming problem, and the efficient strict solution method to find an optimal solution is constructed.

Bias in random forest variable importance measures: Illustrations, sources and a solution

Directory of Open Access Journals (Sweden)

Hothorn Torsten

2007-01-01

Full Text Available Abstract Background Variable importance measures for random forests have been receiving increased attention as a means of variable selection in many classification tasks in bioinformatics and related scientific fields, for instance to select a subset of genetic markers relevant for the prediction of a certain disease. We show that random forest variable importance measures are a sensible means for variable selection in many applications, but are not reliable in situations where potential predictor variables vary in their scale of measurement or their number of categories. This is particularly important in genomics and computational biology, where predictors often include variables of different types, for example when predictors include both sequence data and continuous variables such as folding energy, or when amino acid sequence data show different numbers of categories. Results Simulation studies are presented illustrating that, when random forest variable importance measures are used with data of varying types, the results are misleading because suboptimal predictor variables may be artificially preferred in variable selection. The two mechanisms underlying this deficiency are biased variable selection in the individual classification trees used to build the random forest on one hand, and effects induced by bootstrap sampling with replacement on the other hand. Conclusion We propose to employ an alternative implementation of random forests, that provides unbiased variable selection in the individual classification trees. When this method is applied using subsampling without replacement, the resulting variable importance measures can be used reliably for variable selection even in situations where the potential predictor variables vary in their scale of measurement or their number of categories. The usage of both random forest algorithms and their variable importance measures in the R system for statistical computing is illustrated and

SDE based regression for random PDEs

KAUST Repository

Bayer, Christian

2016-01-01

A simulation based method for the numerical solution of PDE with random coefficients is presented. By the Feynman-Kac formula, the solution can be represented as conditional expectation of a functional of a corresponding stochastic differential equation driven by independent noise. A time discretization of the SDE for a set of points in the domain and a subsequent Monte Carlo regression lead to an approximation of the global solution of the random PDE. We provide an initial error and complexity analysis of the proposed method along with numerical examples illustrating its behaviour.

SDE based regression for random PDEs

KAUST Repository

Bayer, Christian

2016-01-06

A simulation based method for the numerical solution of PDE with random coefficients is presented. By the Feynman-Kac formula, the solution can be represented as conditional expectation of a functional of a corresponding stochastic differential equation driven by independent noise. A time discretization of the SDE for a set of points in the domain and a subsequent Monte Carlo regression lead to an approximation of the global solution of the random PDE. We provide an initial error and complexity analysis of the proposed method along with numerical examples illustrating its behaviour.

Quantitative measure of randomness and order for complete genomes

Science.gov (United States)

Kong, Sing-Guan; Fan, Wen-Lang; Chen, Hong-Da; Wigger, Jan; Torda, Andrew E.; Lee, H. C.

2009-06-01

We propose an order index, ϕ , which gives a quantitative measure of randomness and order of complete genomic sequences. It maps genomes to a number from 0 (random and of infinite length) to 1 (fully ordered) and applies regardless of sequence length. The 786 complete genomic sequences in GenBank were found to have ϕ values in a very narrow range, ϕg=0.031-0.015+0.028 . We show this implies that genomes are halfway toward being completely random, or, at the “edge of chaos.” We further show that artificial “genomes” converted from literary classics have ϕ ’s that almost exactly coincide with ϕg , but sequences of low information content do not. We infer that ϕg represents a high information-capacity “fixed point” in sequence space, and that genomes are driven to it by the dynamics of a robust growth and evolution process. We show that a growth process characterized by random segmental duplication can robustly drive genomes to the fixed point.

A Random-Dot Kinematogram for Web-Based Vision Research

Directory of Open Access Journals (Sweden)

Sivananda Rajananda

2018-01-01

Full Text Available Web-based experiments using visual stimuli have become increasingly common in recent years, but many frequently-used stimuli in vision research have yet to be developed for online platforms. Here, we introduce the first open access random-dot kinematogram (RDK for use in web browsers. This fully customizable RDK offers options to implement several different types of noise (random position, random walk, random direction and parameters to control aperture shape, coherence level, the number of dots, and other features. We include links to commented JavaScript code for easy implementation in web-based experiments, as well as an example of how this stimulus can be integrated as a plugin with a JavaScript library for online studies (jsPsych.

Two Notes on Measure-Theoretic Entropy of Random Dynamical Systems

Institute of Scientific and Technical Information of China (English)

YuJun ZHU

2009-01-01

In this paper, Brin-Katok local entropy formula and Katok's definition of the measure theoretic entropy using spanning set are established for the random dynamical system over an invertible ergodic system.

Novel Schemes for Measurement-Based Quantum Computation

International Nuclear Information System (INIS)

Gross, D.; Eisert, J.

2007-01-01

We establish a framework which allows one to construct novel schemes for measurement-based quantum computation. The technique develops tools from many-body physics--based on finitely correlated or projected entangled pair states--to go beyond the cluster-state based one-way computer. We identify resource states radically different from the cluster state, in that they exhibit nonvanishing correlations, can be prepared using nonmaximally entangling gates, or have very different local entanglement properties. In the computational models, randomness is compensated in a different manner. It is shown that there exist resource states which are locally arbitrarily close to a pure state. We comment on the possibility of tailoring computational models to specific physical systems

Novel schemes for measurement-based quantum computation.

Science.gov (United States)

Gross, D; Eisert, J

2007-06-01

We establish a framework which allows one to construct novel schemes for measurement-based quantum computation. The technique develops tools from many-body physics-based on finitely correlated or projected entangled pair states-to go beyond the cluster-state based one-way computer. We identify resource states radically different from the cluster state, in that they exhibit nonvanishing correlations, can be prepared using nonmaximally entangling gates, or have very different local entanglement properties. In the computational models, randomness is compensated in a different manner. It is shown that there exist resource states which are locally arbitrarily close to a pure state. We comment on the possibility of tailoring computational models to specific physical systems.

A comparison between the original and Tablet-based Symbol Digit Modalities Test in patients with schizophrenia: Test-retest agreement, random measurement error, practice effect, and ecological validity.

Science.gov (United States)

Tang, Shih-Fen; Chen, I-Hui; Chiang, Hsin-Yu; Wu, Chien-Te; Hsueh, I-Ping; Yu, Wan-Hui; Hsieh, Ching-Lin

2017-11-27

We aimed to compare the test-retest agreement, random measurement error, practice effect, and ecological validity of the original and Tablet-based Symbol Digit Modalities Test (T-SDMT) over five serial assessments, and to examine the concurrent validity of the T-SDMT in patients with schizophrenia. Sixty patients with chronic schizophrenia completed five serial assessments (one week apart) of the SDMT and T-SDMT and one assessment of the Activities of Daily Living Rating Scale III at the first time point. Both measures showed high test-retest agreement, similar levels of random measurement error over five serial assessments. Moreover, the practice effects of the two measures did not reach a plateau phase after five serial assessments in young and middle-aged participants. Nevertheless, only the practice effect of the T-SDMT became trivial after the first assessment. Like the SDMT, the T-SDMT had good ecological validity. The T-SDMT also had good concurrent validity with the SDMT. In addition, only the T-SDMT had discriminative validity to discriminate processing speed in young and middle-aged participants. Compared to the SDMT, the T-SDMT had overall slightly better psychometric properties, so it can be an alternative measure to the SDMT for assessing processing speed in patients with schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

Zero-inflated count models for longitudinal measurements with heterogeneous random effects.

Science.gov (United States)

Zhu, Huirong; Luo, Sheng; DeSantis, Stacia M

2017-08-01

Longitudinal zero-inflated count data arise frequently in substance use research when assessing the effects of behavioral and pharmacological interventions. Zero-inflated count models (e.g. zero-inflated Poisson or zero-inflated negative binomial) with random effects have been developed to analyze this type of data. In random effects zero-inflated count models, the random effects covariance matrix is typically assumed to be homogeneous (constant across subjects). However, in many situations this matrix may be heterogeneous (differ by measured covariates). In this paper, we extend zero-inflated count models to account for random effects heterogeneity by modeling their variance as a function of covariates. We show via simulation that ignoring intervention and covariate-specific heterogeneity can produce biased estimates of covariate and random effect estimates. Moreover, those biased estimates can be rectified by correctly modeling the random effects covariance structure. The methodological development is motivated by and applied to the Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence (COMBINE) study, the largest clinical trial of alcohol dependence performed in United States with 1383 individuals.

Link-Based Similarity Measures Using Reachability Vectors

Directory of Open Access Journals (Sweden)

Seok-Ho Yoon

2014-01-01

Full Text Available We present a novel approach for computing link-based similarities among objects accurately by utilizing the link information pertaining to the objects involved. We discuss the problems with previous link-based similarity measures and propose a novel approach for computing link based similarities that does not suffer from these problems. In the proposed approach each target object is represented by a vector. Each element of the vector corresponds to all the objects in the given data, and the value of each element denotes the weight for the corresponding object. As for this weight value, we propose to utilize the probability of reaching from the target object to the specific object, computed using the “Random Walk with Restart” strategy. Then, we define the similarity between two objects as the cosine similarity of the two vectors. In this paper, we provide examples to show that our approach does not suffer from the aforementioned problems. We also evaluate the performance of the proposed methods in comparison with existing link-based measures, qualitatively and quantitatively, with respect to two kinds of data sets, scientific papers and Web documents. Our experimental results indicate that the proposed methods significantly outperform the existing measures.

Study on the algorithm of computational ghost imaging based on discrete fourier transform measurement matrix

Science.gov (United States)

Zhang, Leihong; Liang, Dong; Li, Bei; Kang, Yi; Pan, Zilan; Zhang, Dawei; Gao, Xiumin; Ma, Xiuhua

2016-07-01

On the basis of analyzing the cosine light field with determined analytic expression and the pseudo-inverse method, the object is illuminated by a presetting light field with a determined discrete Fourier transform measurement matrix, and the object image is reconstructed by the pseudo-inverse method. The analytic expression of the algorithm of computational ghost imaging based on discrete Fourier transform measurement matrix is deduced theoretically, and compared with the algorithm of compressive computational ghost imaging based on random measurement matrix. The reconstruction process and the reconstruction error are analyzed. On this basis, the simulation is done to verify the theoretical analysis. When the sampling measurement number is similar to the number of object pixel, the rank of discrete Fourier transform matrix is the same as the one of the random measurement matrix, the PSNR of the reconstruction image of FGI algorithm and PGI algorithm are similar, the reconstruction error of the traditional CGI algorithm is lower than that of reconstruction image based on FGI algorithm and PGI algorithm. As the decreasing of the number of sampling measurement, the PSNR of reconstruction image based on FGI algorithm decreases slowly, and the PSNR of reconstruction image based on PGI algorithm and CGI algorithm decreases sharply. The reconstruction time of FGI algorithm is lower than that of other algorithms and is not affected by the number of sampling measurement. The FGI algorithm can effectively filter out the random white noise through a low-pass filter and realize the reconstruction denoising which has a higher denoising capability than that of the CGI algorithm. The FGI algorithm can improve the reconstruction accuracy and the reconstruction speed of computational ghost imaging.

Optical image encryption based on interference under convergent random illumination

International Nuclear Information System (INIS)

Kumar, Pramod; Joseph, Joby; Singh, Kehar

2010-01-01

In an optical image encryption system based on the interference principle, two pure phase masks are designed analytically to hide an image. These two masks are illuminated with a plane wavefront to retrieve the original image in the form of an interference pattern at the decryption plane. Replacement of the plane wavefront with convergent random illumination in the proposed scheme leads to an improvement in the security of interference based encryption. The proposed encryption scheme retains the simplicity of an interference based method, as the two pure masks are generated with an analytical method without any iterative algorithm. In addition to the free-space propagation distance and the two pure phase masks, the convergence distance and the randomized lens phase function are two new encryption parameters to enhance the system security. The robustness of this scheme against occlusion of the random phase mask of the randomized lens phase function is investigated. The feasibility of the proposed scheme is demonstrated with numerical simulation results

Using complete measurement statistics for optimal device-independent randomness evaluation

International Nuclear Information System (INIS)

Nieto-Silleras, O; Pironio, S; Silman, J

2014-01-01

The majority of recent works investigating the link between non-locality and randomness, e.g. in the context of device-independent cryptography, do so with respect to some specific Bell inequality, usually the CHSH inequality. However, the joint probabilities characterizing the measurement outcomes of a Bell test are richer than just the degree of violation of a single Bell inequality. In this work we show how to take this extra information into account in a systematic manner in order to optimally evaluate the randomness that can be certified from non-local correlations. We further show that taking into account the complete set of outcome probabilities is equivalent to optimizing over all possible Bell inequalities, thereby allowing us to determine the optimal Bell inequality for certifying the maximal amount of randomness from a given set of non-local correlations. (paper)

COMPARISON OF EIGENMODE-BASED AND RANDOM FIELD-BASED IMPERFECTION MODELING FOR THE STOCHASTIC BUCKLING ANALYSIS OF I-SECTION BEAM–COLUMNS

KAUST Repository

STAVREV, A.

2013-03-01

The uncertainty of geometric imperfections in a series of nominally equal I-beams leads to a variability of corresponding buckling loads. Its analysis requires a stochastic imperfection model, which can be derived either by the simple variation of the critical eigenmode with a scalar random variable, or with the help of the more advanced theory of random fields. The present paper first provides a concise review of the two different modeling approaches, covering theoretical background, assumptions and calibration, and illustrates their integration into commercial finite element software to conduct stochastic buckling analyses with the Monte-Carlo method. The stochastic buckling behavior of an example beam is then simulated with both stochastic models, calibrated from corresponding imperfection measurements. The simulation results show that for different load cases, the response statistics of the buckling load obtained with the eigenmode-based and the random field-based models agree very well. A comparison of our simulation results with corresponding Eurocode 3 limit loads indicates that the design standard is very conservative for compression dominated load cases. © 2013 World Scientific Publishing Company.

Some effects of random dose measurement errors on analysis of atomic bomb survivor data

International Nuclear Information System (INIS)

Gilbert, E.S.

1985-01-01

The effects of random dose measurement errors on analyses of atomic bomb survivor data are described and quantified for several procedures. It is found that the ways in which measurement error is most likely to mislead are through downward bias in the estimated regression coefficients and through distortion of the shape of the dose-response curve. The magnitude of the bias with simple linear regression is evaluated for several dose treatments including the use of grouped and ungrouped data, analyses with and without truncation at 600 rad, and analyses which exclude doses exceeding 200 rad. Limited calculations have also been made for maximum likelihood estimation based on Poisson regression. 16 refs., 6 tabs

Towards the generation of random bits at terahertz rates based on a chaotic semiconductor laser

International Nuclear Information System (INIS)

Kanter, Ido; Aviad, Yaara; Reidler, Igor; Cohen, Elad; Rosenbluh, Michael

2010-01-01

Random bit generators (RBGs) are important in many aspects of statistical physics and crucial in Monte-Carlo simulations, stochastic modeling and quantum cryptography. The quality of a RBG is measured by the unpredictability of the bit string it produces and the speed at which the truly random bits can be generated. Deterministic algorithms generate pseudo-random numbers at high data rates as they are only limited by electronic hardware speed, but their unpredictability is limited by the very nature of their deterministic origin. It is widely accepted that the core of any true RBG must be an intrinsically non-deterministic physical process, e.g. measuring thermal noise from a resistor. Owing to low signal levels, such systems are highly susceptible to bias, introduced by amplification, and to small nonrandom external perturbations resulting in a limited generation rate, typically less than 100M bit/s. We present a physical random bit generator, based on a chaotic semiconductor laser, having delayed optical feedback, which operates reliably at rates up to 300Gbit/s. The method uses a high derivative of the digitized chaotic laser intensity and generates the random sequence by retaining a number of the least significant bits of the high derivative value. The method is insensitive to laser operational parameters and eliminates the necessity for all external constraints such as incommensurate sampling rates and laser external cavity round trip time. The randomness of long bit strings is verified by standard statistical tests.

Towards the generation of random bits at terahertz rates based on a chaotic semiconductor laser

Science.gov (United States)

Kanter, Ido; Aviad, Yaara; Reidler, Igor; Cohen, Elad; Rosenbluh, Michael

2010-06-01

Random bit generators (RBGs) are important in many aspects of statistical physics and crucial in Monte-Carlo simulations, stochastic modeling and quantum cryptography. The quality of a RBG is measured by the unpredictability of the bit string it produces and the speed at which the truly random bits can be generated. Deterministic algorithms generate pseudo-random numbers at high data rates as they are only limited by electronic hardware speed, but their unpredictability is limited by the very nature of their deterministic origin. It is widely accepted that the core of any true RBG must be an intrinsically non-deterministic physical process, e.g. measuring thermal noise from a resistor. Owing to low signal levels, such systems are highly susceptible to bias, introduced by amplification, and to small nonrandom external perturbations resulting in a limited generation rate, typically less than 100M bit/s. We present a physical random bit generator, based on a chaotic semiconductor laser, having delayed optical feedback, which operates reliably at rates up to 300Gbit/s. The method uses a high derivative of the digitized chaotic laser intensity and generates the random sequence by retaining a number of the least significant bits of the high derivative value. The method is insensitive to laser operational parameters and eliminates the necessity for all external constraints such as incommensurate sampling rates and laser external cavity round trip time. The randomness of long bit strings is verified by standard statistical tests.

Complexity-Based Measures Inform Effects of Tai Chi Training on Standing Postural Control: Cross-Sectional and Randomized Trial Studies

Science.gov (United States)

Wayne, Peter M.; Gow, Brian J.; Costa, Madalena D.; Peng, C.-K.; Lipsitz, Lewis A.; Hausdorff, Jeffrey M.; Davis, Roger B.; Walsh, Jacquelyn N.; Lough, Matthew; Novak, Vera; Yeh, Gloria Y.; Ahn, Andrew C.; Macklin, Eric A.; Manor, Brad

2014-01-01

Background Diminished control of standing balance, traditionally indicated by greater postural sway magnitude and speed, is associated with falls in older adults. Tai Chi (TC) is a multisystem intervention that reduces fall risk, yet its impact on sway measures vary considerably. We hypothesized that TC improves the integrated function of multiple control systems influencing balance, quantifiable by the multi-scale “complexity” of postural sway fluctuations. Objectives To evaluate both traditional and complexity-based measures of sway to characterize the short- and potential long-term effects of TC training on postural control and the relationships between sway measures and physical function in healthy older adults. Methods A cross-sectional comparison of standing postural sway in healthy TC-naïve and TC-expert (24.5±12 yrs experience) adults. TC-naïve participants then completed a 6-month, two-arm, wait-list randomized clinical trial of TC training. Postural sway was assessed before and after the training during standing on a force-plate with eyes-open (EO) and eyes-closed (EC). Anterior-posterior (AP) and medio-lateral (ML) sway speed, magnitude, and complexity (quantified by multiscale entropy) were calculated. Single-legged standing time and Timed-Up–and-Go tests characterized physical function. Results At baseline, compared to TC-naïve adults (n = 60, age 64.5±7.5 yrs), TC-experts (n = 27, age 62.8±7.5 yrs) exhibited greater complexity of sway in the AP EC (P = 0.023), ML EO (Padults. Trial Registration ClinicalTrials.gov NCT01340365 PMID:25494333

Expectation-based approach for one-dimensional randomly disordered phononic crystals

International Nuclear Information System (INIS)

Wu, Feng; Gao, Qiang; Xu, Xiaoming; Zhong, Wanxie

2014-01-01

An expectation-based approach to the statistical theorem is proposed for the one-dimensional randomly disordered phononic crystal. In the proposed approach, the expectations of the random eigenstates of randomly disordered phononic crystals are investigated. In terms of the expectations of the random eigenstates, the wave propagation and localization phenomenon in the random phononic crystal could be understood in a statistical perspective. Using the proposed approach, it is proved that for a randomly disordered phononic crystal, the Bloch theorem holds in the perspective of expectation. A one-dimensional randomly disordered binary phononic crystal consisting of two materials with the random geometry size or random physical parameter is addressed by using the proposed approach. From the result, it can be observed that with the increase of the disorder degree, the localization of the expectations of the eigenstates is strengthened. The effect of the random disorder on the eigenstates at higher frequencies is more significant than that at lower frequencies. Furthermore, after introducing the random disorder into phononic crystals, some random divergent eigenstates are changed to localized eigenstates in expectation sense.

A Variable Impacts Measurement in Random Forest for Mobile Cloud Computing

Directory of Open Access Journals (Sweden)

Jae-Hee Hur

2017-01-01

Full Text Available Recently, the importance of mobile cloud computing has increased. Mobile devices can collect personal data from various sensors within a shorter period of time and sensor-based data consists of valuable information from users. Advanced computation power and data analysis technology based on cloud computing provide an opportunity to classify massive sensor data into given labels. Random forest algorithm is known as black box model which is hardly able to interpret the hidden process inside. In this paper, we propose a method that analyzes the variable impact in random forest algorithm to clarify which variable affects classification accuracy the most. We apply Shapley Value with random forest to analyze the variable impact. Under the assumption that every variable cooperates as players in the cooperative game situation, Shapley Value fairly distributes the payoff of variables. Our proposed method calculates the relative contributions of the variables within its classification process. In this paper, we analyze the influence of variables and list the priority of variables that affect classification accuracy result. Our proposed method proves its suitability for data interpretation in black box model like a random forest so that the algorithm is applicable in mobile cloud computing environment.

Visibility and aerosol measurement by diode-laser random-modulation CW lidar

Science.gov (United States)

Takeuchi, N.; Baba, H.; Sakurai, K.; Ueno, T.; Ishikawa, N.

1986-01-01

Examples of diode laser (DL) random-modulation continuous wave (RM-CW) lidar measurements are reported. The ability of the measurement of the visibility, vertical aerosol profile, and the cloud ceiling height is demonstrated. Although the data shown here were all measured at night time, the daytime measurement is, of course, possible. For that purpose, accurate control of the laser frequency to the center frequency of a narrow band filter is required. Now a new system with a frequency control is under construction.

Methods of Reverberation Mapping. I. Time-lag Determination by Measures of Randomness

Energy Technology Data Exchange (ETDEWEB)

Chelouche, Doron; Pozo-Nuñez, Francisco [Department of Physics, Faculty of Natural Sciences, University of Haifa, Haifa 3498838 (Israel); Zucker, Shay, E-mail: doron@sci.haifa.ac.il, E-mail: francisco.pozon@gmail.com, E-mail: shayz@post.tau.ac.il [Department of Geosciences, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel)

2017-08-01

A class of methods for measuring time delays between astronomical time series is introduced in the context of quasar reverberation mapping, which is based on measures of randomness or complexity of the data. Several distinct statistical estimators are considered that do not rely on polynomial interpolations of the light curves nor on their stochastic modeling, and do not require binning in correlation space. Methods based on von Neumann’s mean-square successive-difference estimator are found to be superior to those using other estimators. An optimized von Neumann scheme is formulated, which better handles sparsely sampled data and outperforms current implementations of discrete correlation function methods. This scheme is applied to existing reverberation data of varying quality, and consistency with previously reported time delays is found. In particular, the size–luminosity relation of the broad-line region in quasars is recovered with a scatter comparable to that obtained by other works, yet with fewer assumptions made concerning the process underlying the variability. The proposed method for time-lag determination is particularly relevant for irregularly sampled time series, and in cases where the process underlying the variability cannot be adequately modeled.

Quantum random number generator based on quantum nature of vacuum fluctuations

Science.gov (United States)

Ivanova, A. E.; Chivilikhin, S. A.; Gleim, A. V.

2017-11-01

Quantum random number generator (QRNG) allows obtaining true random bit sequences. In QRNG based on quantum nature of vacuum, optical beam splitter with two inputs and two outputs is normally used. We compare mathematical descriptions of spatial beam splitter and fiber Y-splitter in the quantum model for QRNG, based on homodyne detection. These descriptions were identical, that allows to use fiber Y-splitters in practical QRNG schemes, simplifying the setup. Also we receive relations between the input radiation and the resulting differential current in homodyne detector. We experimentally demonstrate possibility of true random bits generation by using QRNG based on homodyne detection with Y-splitter.

Modal Analysis Based on the Random Decrement Transform

DEFF Research Database (Denmark)

Asmussen, J. C.; Brincker, Rune; Ibrahim, S. R.

of this paper is to present a state-of-the-art description of the Random Decrement technique where the statistical theory is outlined and examples are given. But also new results such as estimation of frequency response functions and quality assessment are introduced. Special attention is given......During the last years several papers utilizing the Random Decrement transform as a basis for extraction of modal parameters from the response of linear systems subjected to unknown ambient loads have been presented. Although the Random Decrement technique was developed in a decade starting from...... the introduktion in 1968 the technique seems still to be attractive. This is probably due to the simplicity and the speed of the algorithm and the fact that the theory of the technique has been extended by introducing statistical measures such as correlation functions or spectral densities. The purpose...

On the design of henon and logistic map-based random number generator

Science.gov (United States)

Magfirawaty; Suryadi, M. T.; Ramli, Kalamullah

2017-10-01

The key sequence is one of the main elements in the cryptosystem. True Random Number Generators (TRNG) method is one of the approaches to generating the key sequence. The randomness source of the TRNG divided into three main groups, i.e. electrical noise based, jitter based and chaos based. The chaos based utilizes a non-linear dynamic system (continuous time or discrete time) as an entropy source. In this study, a new design of TRNG based on discrete time chaotic system is proposed, which is then simulated in LabVIEW. The principle of the design consists of combining 2D and 1D chaotic systems. A mathematical model is implemented for numerical simulations. We used comparator process as a harvester method to obtain the series of random bits. Without any post processing, the proposed design generated random bit sequence with high entropy value and passed all NIST 800.22 statistical tests.

How random is a random vector?

Science.gov (United States)

Eliazar, Iddo

2015-12-01

Over 80 years ago Samuel Wilks proposed that the "generalized variance" of a random vector is the determinant of its covariance matrix. To date, the notion and use of the generalized variance is confined only to very specific niches in statistics. In this paper we establish that the "Wilks standard deviation" -the square root of the generalized variance-is indeed the standard deviation of a random vector. We further establish that the "uncorrelation index" -a derivative of the Wilks standard deviation-is a measure of the overall correlation between the components of a random vector. Both the Wilks standard deviation and the uncorrelation index are, respectively, special cases of two general notions that we introduce: "randomness measures" and "independence indices" of random vectors. In turn, these general notions give rise to "randomness diagrams"-tangible planar visualizations that answer the question: How random is a random vector? The notion of "independence indices" yields a novel measure of correlation for Lévy laws. In general, the concepts and results presented in this paper are applicable to any field of science and engineering with random-vectors empirical data.

Effects of curriculum-based measurement on teachers' instructional planning.

Science.gov (United States)

Fuchs, L S; Fuchs, D; Stecker, P M

1989-01-01

This study assessed the effects of curriculum-based measurement (CBM) on teachers' instructional planning. Subjects were 30 teachers, assigned randomly to a computer-assisted CBM group, a noncomputer CBM group, and a contrast group. In the CBM groups, teachers specified 15-week reading goals, established CBM systems to measure student progress toward goals at least twice weekly, and systematically evaluated those data bases to determine when instructional modifications were necessary. Contrast teachers monitored student progress toward Individualized Education Program (IEP) goals as they wished and were encouraged to develop instructional programs as necessary. At the end of a 12- to 15-week implementation period, teachers completed a questionnaire with reference to one randomly selected pupil. Analyses of variance indicated no difference between the CBM groups. However, compared to the contrast group, CBM teachers (a) used more specific, acceptable goals; (b) were less optimistic about goal attainment; (c) cited more objective and frequent data sources for determining the adequacy of student progress and for deciding whether program modifications were necessary; and (d) modified student programs more frequently. Questionnaire responses were correlated with verifiable data sources, and results generally supported the usefulness of the self-report information. Implications for special education research and practice are discussed.

Necessary conditions for the invariant measure of a random walk to be a sum of geometric terms

NARCIS (Netherlands)

Chen, Y.; Boucherie, Richardus J.; Goseling, Jasper

We consider the invariant measure of homogeneous random walks in the quarter-plane. In particular, we consider measures that can be expressed as an infinite sum of geometric terms. We present necessary conditions for the invariant measure of a random walk to be a sum of geometric terms. We

Pseudo-random bit generator based on Chebyshev map

Science.gov (United States)

Stoyanov, B. P.

2013-10-01

In this paper, we study a pseudo-random bit generator based on two Chebyshev polynomial maps. The novel derivative algorithm shows perfect statistical properties established by number of statistical tests.

Multipartite nonlocality and random measurements

Science.gov (United States)

de Rosier, Anna; Gruca, Jacek; Parisio, Fernando; Vértesi, Tamás; Laskowski, Wiesław

2017-07-01

We present an exhaustive numerical analysis of violations of local realism by families of multipartite quantum states. As an indicator of nonclassicality we employ the probability of violation for randomly sampled observables. Surprisingly, it rapidly increases with the number of parties or settings and even for relatively small values local realism is violated for almost all observables. We have observed this effect to be typical in the sense that it emerged for all investigated states including some with randomly drawn coefficients. We also present the probability of violation as a witness of genuine multipartite entanglement.

Brownian motion properties of optoelectronic random bit generators based on laser chaos.

Science.gov (United States)

Li, Pu; Yi, Xiaogang; Liu, Xianglian; Wang, Yuncai; Wang, Yongge

2016-07-11

The nondeterministic property of the optoelectronic random bit generator (RBG) based on laser chaos are experimentally analyzed from two aspects of the central limit theorem and law of iterated logarithm. The random bits are extracted from an optical feedback chaotic laser diode using a multi-bit extraction technique in the electrical domain. Our experimental results demonstrate that the generated random bits have no statistical distance from the Brownian motion, besides that they can pass the state-of-the-art industry-benchmark statistical test suite (NIST SP800-22). All of them give a mathematically provable evidence that the ultrafast random bit generator based on laser chaos can be used as a nondeterministic random bit source.

Brain Tumor Segmentation Based on Random Forest

Directory of Open Access Journals (Sweden)

László Lefkovits

2016-09-01

Full Text Available In this article we present a discriminative model for tumor detection from multimodal MR images. The main part of the model is built around the random forest (RF classifier. We created an optimization algorithm able to select the important features for reducing the dimensionality of data. This method is also used to find out the training parameters used in the learning phase. The algorithm is based on random feature properties for evaluating the importance of the variable, the evolution of learning errors and the proximities between instances. The detection performances obtained have been compared with the most recent systems, offering similar results.

Random amplified polymorphic DNA based genetic characterization ...

African Journals Online (AJOL)

Random amplified polymorphic DNA based genetic characterization of four important species of Bamboo, found in Raigad district, Maharashtra State, India. ... Bambusoideae are differentiated from other members of the family by the presence of petiolate blades with parallel venation and stamens are three, four, six or more, ...

Effectiveness of Wii-based rehabilitation in stroke: A randomized controlled study.

Science.gov (United States)

Karasu, Ayça Utkan; Batur, Elif Balevi; Karataş, Gülçin Kaymak

2018-05-08

To investigate the efficacy of Nintendo Wii Fit®-based balance rehabilitation as an adjunc-tive therapy to conventional rehabilitation in stroke patients. During the study period, 70 stroke patients were evaluated. Of these, 23 who met the study criteria were randomly assigned to either the experimental group (n = 12) or the control group (n = 11) by block randomization. Primary outcome measures were Berg Balance Scale, Functional Reach Test, Postural Assessment Scale for Stroke Patients, Timed Up and Go Test and Static Balance Index. Secondary outcome measures were postural sway, as assessed with Emed-X, Functional Independence Measure Transfer and Ambulation Scores. An evaluator who was blinded to the groups made assessments immediately before (baseline), immediately after (post-treatment), and 4 weeks after completion of the study (follow-up). Group-time interaction was significant in the Berg Balance Scale, Functional Reach Test, anteroposterior and mediolateral centre of pressure displacement with eyes open, anteroposterior centre of pressure displacement with eyes closed, centre of pressure displacement during weight shifting to affected side, to unaffected side and total centre of pressure displacement during weight shifting. Demonstrating significant group-time interaction in those parameters suggests that, while both groups exhibited significant improvement, the experimental group showed greater improvement than the control group. Virtual reality exercises with the Nintendo Wii system could represent a useful adjunctive therapy to traditional treatment to improve static and dynamic balance in stroke patients.

Effectiveness of Wii-based rehabilitation in stroke: A randomized controlled study

Directory of Open Access Journals (Sweden)

Ayça Utkan Karasu

2018-03-01

Full Text Available Objective: To investigate the efficacy of Nintendo Wii Fit®-based balance rehabilitation as an adjunc-tive therapy to conventional rehabilitation in stroke patients. Methods: During the study period, 70 stroke patients were evaluated. Of these, 23 who met the study criteria were randomly assigned to either the experimental group (n = 12 or the control group (n = 11 by block randomization. Primary outcome measures were Berg Balance Scale, Functional Reach Test, Postural Assessment Scale for Stroke Patients, Timed Up and Go Test and Static Balance Index. Secondary outcome measures were postural sway, as assessed with Emed-X, Functional Independence Measure Transfer and Ambulation Scores. An evaluator who was blinded to the groups made assessments immediately before (baseline, immediately after (post-treatment, and 4 weeks after completion of the study (follow-up. Results: Group-time interaction was significant in the Berg Balance Scale, Functional Reach Test, anteroposterior and mediolateral centre of pressure displacement with eyes open, anteroposterior centre of pressure displacement with eyes closed, centre of pressure displacement during weight shifting to affected side, to unaffected side and total centre of pressure displacement during weight shifting. Demonstrating significant group-time interaction in those parameters suggests that, while both groups exhibited significant improvement, the experimental group showed greater improvement than the control group. Conclusion: Virtual reality exercises with the Nintendo Wii system could represent a useful adjunctive therapy to traditional treatment to improve static and dynamic balance in stroke patients.

Pseudo-random bit generator based on lag time series

Science.gov (United States)

García-Martínez, M.; Campos-Cantón, E.

2014-12-01

In this paper, we present a pseudo-random bit generator (PRBG) based on two lag time series of the logistic map using positive and negative values in the bifurcation parameter. In order to hidden the map used to build the pseudo-random series we have used a delay in the generation of time series. These new series when they are mapped xn against xn+1 present a cloud of points unrelated to the logistic map. Finally, the pseudo-random sequences have been tested with the suite of NIST giving satisfactory results for use in stream ciphers.

N-state random switching based on quantum tunnelling

Science.gov (United States)

Bernardo Gavito, Ramón; Jiménez Urbanos, Fernando; Roberts, Jonathan; Sexton, James; Astbury, Benjamin; Shokeir, Hamzah; McGrath, Thomas; Noori, Yasir J.; Woodhead, Christopher S.; Missous, Mohamed; Roedig, Utz; Young, Robert J.

2017-08-01

In this work, we show how the hysteretic behaviour of resonant tunnelling diodes (RTDs) can be exploited for new functionalities. In particular, the RTDs exhibit a stochastic 2-state switching mechanism that could be useful for random number generation and cryptographic applications. This behaviour can be scaled to N-bit switching, by connecting various RTDs in series. The InGaAs/AlAs RTDs used in our experiments display very sharp negative differential resistance (NDR) peaks at room temperature which show hysteresis cycles that, rather than having a fixed switching threshold, show a probability distribution about a central value. We propose to use this intrinsic uncertainty emerging from the quantum nature of the RTDs as a source of randomness. We show that a combination of two RTDs in series results in devices with three-state outputs and discuss the possibility of scaling to N-state devices by subsequent series connections of RTDs, which we demonstrate for the up to the 4-state case. In this work, we suggest using that the intrinsic uncertainty in the conduction paths of resonant tunnelling diodes can behave as a source of randomness that can be integrated into current electronics to produce on-chip true random number generators. The N-shaped I-V characteristic of RTDs results in a two-level random voltage output when driven with current pulse trains. Electrical characterisation and randomness testing of the devices was conducted in order to determine the validity of the true randomness assumption. Based on the results obtained for the single RTD case, we suggest the possibility of using multi-well devices to generate N-state random switching devices for their use in random number generation or multi-valued logic devices.

The generation of 68 Gbps quantum random number by measuring laser phase fluctuations

International Nuclear Information System (INIS)

Nie, You-Qi; Liu, Yang; Zhang, Jun; Pan, Jian-Wei; Huang, Leilei; Payne, Frank

2015-01-01

The speed of a quantum random number generator is essential for practical applications, such as high-speed quantum key distribution systems. Here, we push the speed of a quantum random number generator to 68 Gbps by operating a laser around its threshold level. To achieve the rate, not only high-speed photodetector and high sampling rate are needed but also a very stable interferometer is required. A practical interferometer with active feedback instead of common temperature control is developed to meet the requirement of stability. Phase fluctuations of the laser are measured by the interferometer with a photodetector and then digitalized to raw random numbers with a rate of 80 Gbps. The min-entropy of the raw data is evaluated by modeling the system and is used to quantify the quantum randomness of the raw data. The bias of the raw data caused by other signals, such as classical and detection noises, can be removed by Toeplitz-matrix hashing randomness extraction. The final random numbers can pass through the standard randomness tests. Our demonstration shows that high-speed quantum random number generators are ready for practical usage

Measurement model choice influenced randomized controlled trial results.

Science.gov (United States)

Gorter, Rosalie; Fox, Jean-Paul; Apeldoorn, Adri; Twisk, Jos

2016-11-01

In randomized controlled trials (RCTs), outcome variables are often patient-reported outcomes measured with questionnaires. Ideally, all available item information is used for score construction, which requires an item response theory (IRT) measurement model. However, in practice, the classical test theory measurement model (sum scores) is mostly used, and differences between response patterns leading to the same sum score are ignored. The enhanced differentiation between scores with IRT enables more precise estimation of individual trajectories over time and group effects. The objective of this study was to show the advantages of using IRT scores instead of sum scores when analyzing RCTs. Two studies are presented, a real-life RCT, and a simulation study. Both IRT and sum scores are used to measure the construct and are subsequently used as outcomes for effect calculation. The bias in RCT results is conditional on the measurement model that was used to construct the scores. A bias in estimated trend of around one standard deviation was found when sum scores were used, where IRT showed negligible bias. Accurate statistical inferences are made from an RCT study when using IRT to estimate construct measurements. The use of sum scores leads to incorrect RCT results. Copyright © 2016 Elsevier Inc. All rights reserved.

Text Clustering Algorithm Based on Random Cluster Core

Directory of Open Access Journals (Sweden)

Huang Long-Jun

2016-01-01

Full Text Available Nowadays clustering has become a popular text mining algorithm, but the huge data can put forward higher requirements for the accuracy and performance of text mining. In view of the performance bottleneck of traditional text clustering algorithm, this paper proposes a text clustering algorithm with random features. This is a kind of clustering algorithm based on text density, at the same time using the neighboring heuristic rules, the concept of random cluster is introduced, which effectively reduces the complexity of the distance calculation.

Random walk hierarchy measure: What is more hierarchical, a chain, a tree or a star?

Science.gov (United States)

Czégel, Dániel; Palla, Gergely

2015-12-10

Signs of hierarchy are prevalent in a wide range of systems in nature and society. One of the key problems is quantifying the importance of hierarchical organisation in the structure of the network representing the interactions or connections between the fundamental units of the studied system. Although a number of notable methods are already available, their vast majority is treating all directed acyclic graphs as already maximally hierarchical. Here we propose a hierarchy measure based on random walks on the network. The novelty of our approach is that directed trees corresponding to multi level pyramidal structures obtain higher hierarchy scores compared to directed chains and directed stars. Furthermore, in the thermodynamic limit the hierarchy measure of regular trees is converging to a well defined limit depending only on the branching number. When applied to real networks, our method is computationally very effective, as the result can be evaluated with arbitrary precision by subsequent multiplications of the transition matrix describing the random walk process. In addition, the tests on real world networks provided very intuitive results, e.g., the trophic levels obtained from our approach on a food web were highly consistent with former results from ecology.

Random walk hierarchy measure: What is more hierarchical, a chain, a tree or a star?

Science.gov (United States)

Czégel, Dániel; Palla, Gergely

2015-01-01

Signs of hierarchy are prevalent in a wide range of systems in nature and society. One of the key problems is quantifying the importance of hierarchical organisation in the structure of the network representing the interactions or connections between the fundamental units of the studied system. Although a number of notable methods are already available, their vast majority is treating all directed acyclic graphs as already maximally hierarchical. Here we propose a hierarchy measure based on random walks on the network. The novelty of our approach is that directed trees corresponding to multi level pyramidal structures obtain higher hierarchy scores compared to directed chains and directed stars. Furthermore, in the thermodynamic limit the hierarchy measure of regular trees is converging to a well defined limit depending only on the branching number. When applied to real networks, our method is computationally very effective, as the result can be evaluated with arbitrary precision by subsequent multiplications of the transition matrix describing the random walk process. In addition, the tests on real world networks provided very intuitive results, e.g., the trophic levels obtained from our approach on a food web were highly consistent with former results from ecology. PMID:26657012

Multimedia based health information to parents in a pediatric acute ward: a randomized controlled trial.

Science.gov (United States)

Botngård, Anja; Skranes, Lars P; Skranes, Jon; Døllner, Henrik

2013-12-01

To determine whether multimedia based health information presented to parents of children with breathing difficulties in a pediatric acute ward, is more effective than verbal information, to reduce parental anxiety and increase satisfaction. This randomized controlled trial was conducted in a pediatric acute ward in Norway, from January to March 2011. Parents were randomly assigned to a multimedia intervention (n=53), or verbal health information (n=48). Primary outcome measure was parental anxiety, and secondary outcome measures were parental satisfaction with nursing care and health information. Parental anxiety decreased from arrival to discharge within both groups. At discharge the anxiety levels in the intervention group were no lower than in the control group. There was no difference in satisfaction with nursing care between the groups, but parents in the intervention group reported higher satisfaction with the health information given in the acute ward (p=.005). Multimedia based health information did not reduce anxiety more than verbal information, among parents to children with breathing difficulties. However, after discharge the parents were more satisfied with the multimedia approach. More research is needed to recommend the use of multimedia based information as a routine to parents in pediatric emergency care. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Evaluation of a Drowning Prevention Program Based on Testimonial Videos: A Randomized Controlled Trial.

Science.gov (United States)

Shen, Jiabin; Pang, Shulan; Schwebel, David C

2016-06-01

Unintentional drowning is the most common cause of childhood death in rural China. Global intervention efforts offer mixed results regarding the efficacy of educational programs. Using a randomized controlled design, we evaluated a testimonial-based intervention to reduce drowning risk among 280 3rd- and 4th-grade rural Chinese children. Children were randomly assigned to view either testimonials on drowning risk (intervention) or dog-bite risk (control). Safety knowledge and perceived vulnerability were measured by self-report questionnaires, and simulated behaviors in and near water were assessed with a culturally appropriate dollhouse task. Children in the intervention group had improved children's safety knowledge and simulated behaviors but not perceived vulnerability compared with controls. The testimonial-based intervention's efficacy appears promising, as it improved safety knowledge and simulated risk behaviors with water among rural Chinese children. © The Author 2015. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Chaos-based Pseudo-random Number Generation

KAUST Repository

Barakat, Mohamed L.

2014-04-10

Various methods and systems related to chaos-based pseudo-random number generation are presented. In one example, among others, a system includes a pseudo-random number generator (PRNG) to generate a series of digital outputs and a nonlinear post processing circuit to perform an exclusive OR (XOR) operation on a first portion of a current digital output of the PRNG and a permutated version of a corresponding first portion of a previous post processed output to generate a corresponding first portion of a current post processed output. In another example, a method includes receiving at least a first portion of a current output from a PRNG and performing an XOR operation on the first portion of the current PRNG output with a permutated version of a corresponding first portion of a previous post processed output to generate a corresponding first portion of a current post processed output.

Chaos-based Pseudo-random Number Generation

KAUST Repository

Barakat, Mohamed L.; Mansingka, Abhinav S.; Radwan, Ahmed Gomaa Ahmed; Salama, Khaled N.

2014-01-01

Various methods and systems related to chaos-based pseudo-random number generation are presented. In one example, among others, a system includes a pseudo-random number generator (PRNG) to generate a series of digital outputs and a nonlinear post processing circuit to perform an exclusive OR (XOR) operation on a first portion of a current digital output of the PRNG and a permutated version of a corresponding first portion of a previous post processed output to generate a corresponding first portion of a current post processed output. In another example, a method includes receiving at least a first portion of a current output from a PRNG and performing an XOR operation on the first portion of the current PRNG output with a permutated version of a corresponding first portion of a previous post processed output to generate a corresponding first portion of a current post processed output.

Deviation rectification for dynamic measurement of rail wear based on coordinate sets projection

International Nuclear Information System (INIS)

Wang, Chao; Ma, Ziji; Li, Yanfu; Liu, Hongli; Zeng, Jiuzhen; Jin, Tan

2017-01-01

Dynamic measurement of rail wear using a laser imaging system suffers from random vibrations in the laser-based imaging sensor which cause distorted rail profiles. In this paper, a simple and effective method for rectifying profile deviation is presented to address this issue. There are two main steps: profile recognition and distortion calibration. According to the constant camera and projector parameters, efficient recognition of measured profiles is achieved by analyzing the geometric difference between normal profiles and distorted ones. For a distorted profile, by constructing coordinate sets projecting from it to the standard one on triple projecting primitives, including the rail head inner line, rail waist curve and rail jaw, iterative extrinsic camera parameter self-compensation is implemented. The distortion is calibrated by projecting the distorted profile onto the x – y plane of a measuring coordinate frame, which is parallel to the rail cross section, to eliminate the influence of random vibrations in the laser-based imaging sensor. As well as evaluating the implementation with comprehensive experiments, we also compare our method with other published works. The results exhibit the effectiveness and superiority of our method for the dynamic measurement of rail wear. (paper)

Deviation rectification for dynamic measurement of rail wear based on coordinate sets projection

Science.gov (United States)

Wang, Chao; Ma, Ziji; Li, Yanfu; Zeng, Jiuzhen; Jin, Tan; Liu, Hongli

2017-10-01

Dynamic measurement of rail wear using a laser imaging system suffers from random vibrations in the laser-based imaging sensor which cause distorted rail profiles. In this paper, a simple and effective method for rectifying profile deviation is presented to address this issue. There are two main steps: profile recognition and distortion calibration. According to the constant camera and projector parameters, efficient recognition of measured profiles is achieved by analyzing the geometric difference between normal profiles and distorted ones. For a distorted profile, by constructing coordinate sets projecting from it to the standard one on triple projecting primitives, including the rail head inner line, rail waist curve and rail jaw, iterative extrinsic camera parameter self-compensation is implemented. The distortion is calibrated by projecting the distorted profile onto the x-y plane of a measuring coordinate frame, which is parallel to the rail cross section, to eliminate the influence of random vibrations in the laser-based imaging sensor. As well as evaluating the implementation with comprehensive experiments, we also compare our method with other published works. The results exhibit the effectiveness and superiority of our method for the dynamic measurement of rail wear.

Ultrafast quantum random number generation based on quantum phase fluctuations.

Science.gov (United States)

Xu, Feihu; Qi, Bing; Ma, Xiongfeng; Xu, He; Zheng, Haoxuan; Lo, Hoi-Kwong

2012-05-21

A quantum random number generator (QRNG) can generate true randomness by exploiting the fundamental indeterminism of quantum mechanics. Most approaches to QRNG employ single-photon detection technologies and are limited in speed. Here, we experimentally demonstrate an ultrafast QRNG at a rate over 6 Gbits/s based on the quantum phase fluctuations of a laser operating near threshold. Moreover, we consider a potential adversary who has partial knowledge on the raw data and discuss how one can rigorously remove such partial knowledge with postprocessing. We quantify the quantum randomness through min-entropy by modeling our system and employ two randomness extractors--Trevisan's extractor and Toeplitz-hashing--to distill the randomness, which is information-theoretically provable. The simplicity and high-speed of our experimental setup show the feasibility of a robust, low-cost, high-speed QRNG.

Implementing traceability using particle randomness-based textile printed tags

Science.gov (United States)

Agrawal, T. K.; Koehl, L.; Campagne, C.

2017-10-01

This article introduces a random particle-based traceability tag for textiles. The proposed tag not only act as a unique signature for the corresponding textile product but also possess the features such as easy to manufacture and hard to copy. It seeks applications in brand authentication and traceability in textile and clothing (T&C) supply chain. A prototype has been developed by screen printing process, in which micron-scale particles were mixed with the printing paste and printed on cotton fabrics to attain required randomness. To encode the randomness, the image of the developed tag was taken and analyzed using image processing. The randomness of the particles acts as a product key or unique signature which is required to decode the tag. Finally, washing and abrasion resistance tests were conducted to check the durability of the printed tag.

Internet-based cognitive-behavior therapy for procrastination: A randomized controlled trial.

Science.gov (United States)

Rozental, Alexander; Forsell, Erik; Svensson, Andreas; Andersson, Gerhard; Carlbring, Per

2015-08-01

Procrastination can be a persistent behavior pattern associated with personal distress. However, research investigating different treatment interventions is scarce, and no randomized controlled trial has examined the efficacy of cognitive-behavior therapy (CBT). Meanwhile, Internet-based CBT has been found promising for several conditions, but has not yet been used for procrastination. Participants (N = 150) were randomized to guided self-help, unguided self-help, and wait-list control. Outcome measures were administered before and after treatment, or weekly throughout the treatment period. They included the Pure Procrastination Scale, the Irrational Procrastination Scale, the Susceptibility to Temptation Scale, the Montgomery Åsberg Depression Rating Scale-Self-report version, the Generalized Anxiety Disorder Assessment, and the Quality of Life Inventory. The intention-to-treat principle was used for all statistical analyses. Mixed-effects models revealed moderate between-groups effect sizes comparing guided and unguided self-help with wait-list control; the Pure Procrastination Scale, Cohen's d = 0.70, 95% confidence interval (CI) [0.29, 1.10], and d = 0.50, 95% CI [0.10, 0.90], and the Irrational Procrastination Scale, d = 0.81 95% CI [0.40, 1.22], and d = 0.69 95% CI [0.29, 1.09]. Clinically significant change was achieved among 31.3-40.0% for guided self-help, compared with 24.0-36.0% for unguided self-help. Neither of the treatment conditions was found to be superior on any of the outcome measures, Fs(98, 65.17-72.55) .19. Internet-based CBT could be useful for managing self-reported difficulties due to procrastination, both with and without the guidance of a therapist. (c) 2015 APA, all rights reserved).

Retention of Statistical Concepts in a Preliminary Randomization-Based Introductory Statistics Curriculum

Science.gov (United States)

Tintle, Nathan; Topliff, Kylie; VanderStoep, Jill; Holmes, Vicki-Lynn; Swanson, Todd

2012-01-01

Previous research suggests that a randomization-based introductory statistics course may improve student learning compared to the consensus curriculum. However, it is unclear whether these gains are retained by students post-course. We compared the conceptual understanding of a cohort of students who took a randomization-based curriculum (n = 76)…

The invariant measure of random walks in the quarter-plane: respresentation in geometric terms

NARCIS (Netherlands)

Chen, Y.; Boucherie, Richardus J.; Goseling, Jasper

We consider the invariant measure of homogeneous random walks in the quarter-plane. In particular, we consider measures that can be expressed as a finite linear combination of geometric terms and present conditions on the structure of these linear combinations such that the resulting measure may

A randomized, controlled trial of team-based competition to increase learner participation in quality-improvement education.

Science.gov (United States)

Scales, Charles D; Moin, Tannaz; Fink, Arlene; Berry, Sandra H; Afsar-Manesh, Nasim; Mangione, Carol M; Kerfoot, B Price

2016-04-01

Several barriers challenge resident engagement in learning quality improvement (QI). We investigated whether the incorporation of team-based game mechanics into an evidence-based online learning platform could increase resident participation in a QI curriculum. Randomized, controlled trial. Tertiary-care medical center residency training programs. Resident physicians (n = 422) from nine training programs (anesthesia, emergency medicine, family medicine, internal medicine, ophthalmology, orthopedics, pediatrics, psychiatry and general surgery) randomly allocated to a team competition environment (n = 200) or the control group (n = 222). Specialty-based team assignment with leaderboards to foster competition, and alias assignment to de-identify individual participants. Participation in online learning, as measured by percentage of questions attempted (primary outcome) and additional secondary measures of engagement (i.e. response time). Changes in participation measures over time between groups were assessed with a repeated measures ANOVA framework. Residents in the intervention arm demonstrated greater participation than the control group. The percentage of questions attempted at least once was greater in the competition group (79% [SD ± 32] versus control, 68% [SD ± 37], P= 0.03). Median response time was faster in the competition group (P= 0.006). Differences in participation continued to increase over the duration of the intervention, as measured by average response time and cumulative percent of questions attempted (each Ponline course delivering QI content. Medical educators should consider game mechanics to optimize participation when designing learning experiences. Published by Oxford University Press in association with the International Society for Quality in Health Care 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

True random number generation from mobile telephone photo based on chaotic cryptography

International Nuclear Information System (INIS)

Zhao Liang; Liao Xiaofeng; Xiao Di; Xiang Tao; Zhou Qing; Duan Shukai

2009-01-01

A cheap, convenient and universal TRNG based on mobile telephone photo for producing random bit sequence is proposed. To settle the problem of sequential pixels and comparability, three chaos-based approaches are applied to post-process the generated binary image. The random numbers produced by three users are tested using US NIST RNG statistical test software. The experimental results indicate that the Arnold cat map is the fastest way to generate a random bit sequence and can be accepted on general PC. The 'MASK' algorithm also performs well. Finally, comparing with the TRNG of Hu et al. [Hu Y, Liao X, Wong KW, Zhou Q. A true random number generator based on mouse movement and chaotic cryptography. Chaos, Solitons and Fractals 2007. doi: 10.1016/j.chaos.2007.10.022] which is presented by Hu et al., many merits of the proposed TRNG in this paper has been found.

Random number generation based on digital differential chaos

KAUST Repository

Zidan, Mohammed A.; Radwan, Ahmed G.; Salama, Khaled N.

2012-01-01

In this paper, we present a fully digital differential chaos based random number generator. The output of the digital circuit is proved to be chaotic by calculating the output time series maximum Lyapunov exponent. We introduce a new post processing

Arbitrary-step randomly delayed robust filter with application to boost phase tracking

Science.gov (United States)

Qin, Wutao; Wang, Xiaogang; Bai, Yuliang; Cui, Naigang

2018-04-01

The conventional filters such as extended Kalman filter, unscented Kalman filter and cubature Kalman filter assume that the measurement is available in real-time and the measurement noise is Gaussian white noise. But in practice, both two assumptions are invalid. To solve this problem, a novel algorithm is proposed by taking the following four steps. At first, the measurement model is modified by the Bernoulli random variables to describe the random delay. Then, the expression of predicted measurement and covariance are reformulated, which could get rid of the restriction that the maximum number of delay must be one or two and the assumption that probabilities of Bernoulli random variables taking the value one are equal. Next, the arbitrary-step randomly delayed high-degree cubature Kalman filter is derived based on the 5th-degree spherical-radial rule and the reformulated expressions. Finally, the arbitrary-step randomly delayed high-degree cubature Kalman filter is modified to the arbitrary-step randomly delayed high-degree cubature Huber-based filter based on the Huber technique, which is essentially an M-estimator. Therefore, the proposed filter is not only robust to the randomly delayed measurements, but robust to the glint noise. The application to the boost phase tracking example demonstrate the superiority of the proposed algorithms.

Standardized Effect Size Measures for Mediation Analysis in Cluster-Randomized Trials

Science.gov (United States)

Stapleton, Laura M.; Pituch, Keenan A.; Dion, Eric

2015-01-01

This article presents 3 standardized effect size measures to use when sharing results of an analysis of mediation of treatment effects for cluster-randomized trials. The authors discuss 3 examples of mediation analysis (upper-level mediation, cross-level mediation, and cross-level mediation with a contextual effect) with demonstration of the…

Concise biomarker for spatial-temporal change in three-dimensional ultrasound measurement of carotid vessel wall and plaque thickness based on a graph-based random walk framework: Towards sensitive evaluation of response to therapy.

Science.gov (United States)

Chiu, Bernard; Chen, Weifu; Cheng, Jieyu

2016-12-01

Rapid progression in total plaque area and volume measured from ultrasound images has been shown to be associated with an elevated risk of cardiovascular events. Since atherosclerosis is focal and predominantly occurring at the bifurcation, biomarkers that are able to quantify the spatial distribution of vessel-wall-plus-plaque thickness (VWT) change may allow for more sensitive detection of treatment effect. The goal of this paper is to develop simple and sensitive biomarkers to quantify the responsiveness to therapies based on the spatial distribution of VWT-Change on the entire 2D carotid standardized map previously described. Point-wise VWT-Changes computed for each patient were reordered lexicographically to a high-dimensional data node in a graph. A graph-based random walk framework was applied with the novel Weighted Cosine (WCos) similarity function introduced, which was tailored for quantification of responsiveness to therapy. The converging probability of each data node to the VWT regression template in the random walk process served as a scalar descriptor for VWT responsiveness to treatment. The WCos-based biomarker was 14 times more sensitive than the mean VWT-Change in discriminating responsive and unresponsive subjects based on the p-values obtained in T-tests. The proposed framework was extended to quantify where VWT-Change occurred by including multiple VWT-Change distribution templates representing focal changes at different regions. Experimental results show that the framework was effective in classifying carotid arteries with focal VWT-Change at different locations and may facilitate future investigations to correlate risk of cardiovascular events with the location where focal VWT-Change occurs. Copyright © 2016 Elsevier Ltd. All rights reserved.

How random is a random vector?

International Nuclear Information System (INIS)

Eliazar, Iddo

2015-01-01

Over 80 years ago Samuel Wilks proposed that the “generalized variance” of a random vector is the determinant of its covariance matrix. To date, the notion and use of the generalized variance is confined only to very specific niches in statistics. In this paper we establish that the “Wilks standard deviation” –the square root of the generalized variance–is indeed the standard deviation of a random vector. We further establish that the “uncorrelation index” –a derivative of the Wilks standard deviation–is a measure of the overall correlation between the components of a random vector. Both the Wilks standard deviation and the uncorrelation index are, respectively, special cases of two general notions that we introduce: “randomness measures” and “independence indices” of random vectors. In turn, these general notions give rise to “randomness diagrams”—tangible planar visualizations that answer the question: How random is a random vector? The notion of “independence indices” yields a novel measure of correlation for Lévy laws. In general, the concepts and results presented in this paper are applicable to any field of science and engineering with random-vectors empirical data.

Age replacement policy based on imperfect repair with random probability

International Nuclear Information System (INIS)

Lim, J.H.; Qu, Jian; Zuo, Ming J.

2016-01-01

In most of literatures of age replacement policy, failures before planned replacement age can be either minimally repaired or perfectly repaired based on the types of failures, cost for repairs and so on. In this paper, we propose age replacement policy based on imperfect repair with random probability. The proposed policy incorporates the case that such intermittent failure can be either minimally repaired or perfectly repaired with random probabilities. The mathematical formulas of the expected cost rate per unit time are derived for both the infinite-horizon case and the one-replacement-cycle case. For each case, we show that the optimal replacement age exists and is finite. - Highlights: • We propose a new age replacement policy with random probability of perfect repair. • We develop the expected cost per unit time. • We discuss the optimal age for replacement minimizing the expected cost rate.

An improved label propagation algorithm based on node importance and random walk for community detection

Science.gov (United States)

Ma, Tianren; Xia, Zhengyou

2017-05-01

Currently, with the rapid development of information technology, the electronic media for social communication is becoming more and more popular. Discovery of communities is a very effective way to understand the properties of complex networks. However, traditional community detection algorithms consider the structural characteristics of a social organization only, with more information about nodes and edges wasted. In the meanwhile, these algorithms do not consider each node on its merits. Label propagation algorithm (LPA) is a near linear time algorithm which aims to find the community in the network. It attracts many scholars owing to its high efficiency. In recent years, there are more improved algorithms that were put forward based on LPA. In this paper, an improved LPA based on random walk and node importance (NILPA) is proposed. Firstly, a list of node importance is obtained through calculation. The nodes in the network are sorted in descending order of importance. On the basis of random walk, a matrix is constructed to measure the similarity of nodes and it avoids the random choice in the LPA. Secondly, a new metric IAS (importance and similarity) is calculated by node importance and similarity matrix, which we can use to avoid the random selection in the original LPA and improve the algorithm stability. Finally, a test in real-world and synthetic networks is given. The result shows that this algorithm has better performance than existing methods in finding community structure.

Strong Tracking Filter for Nonlinear Systems with Randomly Delayed Measurements and Correlated Noises

Directory of Open Access Journals (Sweden)

Hongtao Yang

2018-01-01

Full Text Available This paper proposes a novel strong tracking filter (STF, which is suitable for dealing with the filtering problem of nonlinear systems when the following cases occur: that is, the constructed model does not match the actual system, the measurements have the one-step random delay, and the process and measurement noises are correlated at the same epoch. Firstly, a framework of decoupling filter (DF based on equivalent model transformation is derived. Further, according to the framework of DF, a new extended Kalman filtering (EKF algorithm via using first-order linearization approximation is developed. Secondly, the computational process of the suboptimal fading factor is derived on the basis of the extended orthogonality principle (EOP. Thirdly, the ultimate form of the proposed STF is obtained by introducing the suboptimal fading factor into the above EKF algorithm. The proposed STF can automatically tune the suboptimal fading factor on the basis of the residuals between available and predicted measurements and further the gain matrices of the proposed STF tune online to improve the filtering performance. Finally, the effectiveness of the proposed STF has been proved through numerical simulation experiments.

Random-Profiles-Based 3D Face Recognition System

Directory of Open Access Journals (Sweden)

Joongrock Kim

2014-03-01

Full Text Available In this paper, a noble nonintrusive three-dimensional (3D face modeling system for random-profile-based 3D face recognition is presented. Although recent two-dimensional (2D face recognition systems can achieve a reliable recognition rate under certain conditions, their performance is limited by internal and external changes, such as illumination and pose variation. To address these issues, 3D face recognition, which uses 3D face data, has recently received much attention. However, the performance of 3D face recognition highly depends on the precision of acquired 3D face data, while also requiring more computational power and storage capacity than 2D face recognition systems. In this paper, we present a developed nonintrusive 3D face modeling system composed of a stereo vision system and an invisible near-infrared line laser, which can be directly applied to profile-based 3D face recognition. We further propose a novel random-profile-based 3D face recognition method that is memory-efficient and pose-invariant. The experimental results demonstrate that the reconstructed 3D face data consists of more than 50 k 3D point clouds and a reliable recognition rate against pose variation.

Blind Measurement Selection: A Random Matrix Theory Approach

KAUST Repository

Elkhalil, Khalil

2016-12-14

This paper considers the problem of selecting a set of $k$ measurements from $n$ available sensor observations. The selected measurements should minimize a certain error function assessing the error in estimating a certain $m$ dimensional parameter vector. The exhaustive search inspecting each of the $n\\\\choose k$ possible choices would require a very high computational complexity and as such is not practical for large $n$ and $k$. Alternative methods with low complexity have recently been investigated but their main drawbacks are that 1) they require perfect knowledge of the measurement matrix and 2) they need to be applied at the pace of change of the measurement matrix. To overcome these issues, we consider the asymptotic regime in which $k$, $n$ and $m$ grow large at the same pace. Tools from random matrix theory are then used to approximate in closed-form the most important error measures that are commonly used. The asymptotic approximations are then leveraged to select properly $k$ measurements exhibiting low values for the asymptotic error measures. Two heuristic algorithms are proposed: the first one merely consists in applying the convex optimization artifice to the asymptotic error measure. The second algorithm is a low-complexity greedy algorithm that attempts to look for a sufficiently good solution for the original minimization problem. The greedy algorithm can be applied to both the exact and the asymptotic error measures and can be thus implemented in blind and channel-aware fashions. We present two potential applications where the proposed algorithms can be used, namely antenna selection for uplink transmissions in large scale multi-user systems and sensor selection for wireless sensor networks. Numerical results are also presented and sustain the efficiency of the proposed blind methods in reaching the performances of channel-aware algorithms.

Reconstruction of photon number conditioned states using phase randomized homodyne measurements

International Nuclear Information System (INIS)

Chrzanowski, H M; Assad, S M; Bernu, J; Hage, B; Lam, P K; Symul, T; Lund, A P; Ralph, T C

2013-01-01

We experimentally demonstrate the reconstruction of a photon number conditioned state without using a photon number discriminating detector. By using only phase randomized homodyne measurements, we reconstruct up to the three photon subtracted squeezed vacuum state. The reconstructed Wigner functions of these states show regions of pronounced negativity, signifying the non-classical nature of the reconstructed states. The techniques presented allow for complete characterization of the role of a conditional measurement on an ensemble of states, and might prove useful in systems where photon counting still proves technically challenging. (paper)

Canonical Naimark extension for generalized measurements involving sets of Pauli quantum observables chosen at random

Science.gov (United States)

Sparaciari, Carlo; Paris, Matteo G. A.

2013-01-01

We address measurement schemes where certain observables Xk are chosen at random within a set of nondegenerate isospectral observables and then measured on repeated preparations of a physical system. Each observable has a probability zk to be measured, with ∑kzk=1, and the statistics of this generalized measurement is described by a positive operator-valued measure. This kind of scheme is referred to as quantum roulettes, since each observable Xk is chosen at random, e.g., according to the fluctuating value of an external parameter. Here we focus on quantum roulettes for qubits involving the measurements of Pauli matrices, and we explicitly evaluate their canonical Naimark extensions, i.e., their implementation as indirect measurements involving an interaction scheme with a probe system. We thus provide a concrete model to realize the roulette without destroying the signal state, which can be measured again after the measurement or can be transmitted. Finally, we apply our results to the description of Stern-Gerlach-like experiments on a two-level system.

A new simple technique for improving the random properties of chaos-based cryptosystems

Science.gov (United States)

Garcia-Bosque, M.; Pérez-Resa, A.; Sánchez-Azqueta, C.; Celma, S.

2018-03-01

A new technique for improving the security of chaos-based stream ciphers has been proposed and tested experimentally. This technique manages to improve the randomness properties of the generated keystream by preventing the system to fall into short period cycles due to digitation. In order to test this technique, a stream cipher based on a Skew Tent Map algorithm has been implemented on a Virtex 7 FPGA. The randomness of the keystream generated by this system has been compared to the randomness of the keystream generated by the same system with the proposed randomness-enhancement technique. By subjecting both keystreams to the National Institute of Standards and Technology (NIST) tests, we have proved that our method can considerably improve the randomness of the generated keystreams. In order to incorporate our randomness-enhancement technique, only 41 extra slices have been needed, proving that, apart from effective, this method is also efficient in terms of area and hardware resources.

A Correction of Random Incidence Absorption Coefficients for the Angular Distribution of Acoustic Energy under Measurement Conditions

DEFF Research Database (Denmark)

Jeong, Cheol-Ho

2009-01-01

Most acoustic measurements are based on an assumption of ideal conditions. One such ideal condition is a diffuse and reverberant field. In practice, a perfectly diffuse sound field cannot be achieved in a reverberation chamber. Uneven incident energy density under measurement conditions can cause...... discrepancies between the measured value and the theoretical random incidence absorption coefficient. Therefore the angular distribution of the incident acoustic energy onto an absorber sample should be taken into account. The angular distribution of the incident energy density was simulated using the beam...... tracing method for various room shapes and source positions. The averaged angular distribution is found to be similar to a Gaussian distribution. As a result, an angle-weighted absorption coefficient was proposed by considering the angular energy distribution to improve the agreement between...

A random spatial network model based on elementary postulates

Science.gov (United States)

Karlinger, Michael R.; Troutman, Brent M.

1989-01-01

A model for generating random spatial networks that is based on elementary postulates comparable to those of the random topology model is proposed. In contrast to the random topology model, this model ascribes a unique spatial specification to generated drainage networks, a distinguishing property of some network growth models. The simplicity of the postulates creates an opportunity for potential analytic investigations of the probabilistic structure of the drainage networks, while the spatial specification enables analyses of spatially dependent network properties. In the random topology model all drainage networks, conditioned on magnitude (number of first-order streams), are equally likely, whereas in this model all spanning trees of a grid, conditioned on area and drainage density, are equally likely. As a result, link lengths in the generated networks are not independent, as usually assumed in the random topology model. For a preliminary model evaluation, scale-dependent network characteristics, such as geometric diameter and link length properties, and topologic characteristics, such as bifurcation ratio, are computed for sets of drainage networks generated on square and rectangular grids. Statistics of the bifurcation and length ratios fall within the range of values reported for natural drainage networks, but geometric diameters tend to be relatively longer than those for natural networks.

Analysis of covariance with pre-treatment measurements in randomized trials: comparison of equal and unequal slopes.

Science.gov (United States)

Funatogawa, Ikuko; Funatogawa, Takashi

2011-09-01

In randomized trials, an analysis of covariance (ANCOVA) is often used to analyze post-treatment measurements with pre-treatment measurements as a covariate to compare two treatment groups. Random allocation guarantees only equal variances of pre-treatment measurements. We hence consider data with unequal covariances and variances of post-treatment measurements without assuming normality. Recently, we showed that the actual type I error rate of the usual ANCOVA assuming equal slopes and equal residual variances is asymptotically at a nominal level under equal sample sizes, and that of the ANCOVA with unequal variances is asymptotically at a nominal level, even under unequal sample sizes. In this paper, we investigated the asymptotic properties of the ANCOVA with unequal slopes for such data. The estimators of the treatment effect at the observed mean are identical between equal and unequal variance assumptions, and these are asymptotically normal estimators for the treatment effect at the true mean. However, the variances of these estimators based on standard formulas are biased, and the actual type I error rates are not at a nominal level, irrespective of variance assumptions. In equal sample sizes, the efficiency of the usual ANCOVA assuming equal slopes and equal variances is asymptotically the same as those of the ANCOVA with unequal slopes and higher than that of the ANCOVA with equal slopes and unequal variances. Therefore, the use of the usual ANCOVA is appropriate in equal sample sizes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Randomized Caches Considered Harmful in Hard Real-Time Systems

Directory of Open Access Journals (Sweden)

Jan Reineke

2014-06-01

Full Text Available We investigate the suitability of caches with randomized placement and replacement in the context of hard real-time systems. Such caches have been claimed to drastically reduce the amount of information required by static worst-case execution time (WCET analysis, and to be an enabler for measurement-based probabilistic timing analysis. We refute these claims and conclude that with prevailing static and measurement-based analysis techniques caches with deterministic placement and least-recently-used replacement are preferable over randomized ones.

Random Fields

Science.gov (United States)

Vanmarcke, Erik

1983-03-01

Random variation over space and time is one of the few attributes that might safely be predicted as characterizing almost any given complex system. Random fields or "distributed disorder systems" confront astronomers, physicists, geologists, meteorologists, biologists, and other natural scientists. They appear in the artifacts developed by electrical, mechanical, civil, and other engineers. They even underlie the processes of social and economic change. The purpose of this book is to bring together existing and new methodologies of random field theory and indicate how they can be applied to these diverse areas where a "deterministic treatment is inefficient and conventional statistics insufficient." Many new results and methods are included. After outlining the extent and characteristics of the random field approach, the book reviews the classical theory of multidimensional random processes and introduces basic probability concepts and methods in the random field context. It next gives a concise amount of the second-order analysis of homogeneous random fields, in both the space-time domain and the wave number-frequency domain. This is followed by a chapter on spectral moments and related measures of disorder and on level excursions and extremes of Gaussian and related random fields. After developing a new framework of analysis based on local averages of one-, two-, and n-dimensional processes, the book concludes with a chapter discussing ramifications in the important areas of estimation, prediction, and control. The mathematical prerequisite has been held to basic college-level calculus.

Estimates of Inequality Indices Based on Simple Random, Ranked Set, and Systematic Sampling

OpenAIRE

Bansal, Pooja; Arora, Sangeeta; Mahajan, Kalpana K.

2013-01-01

Gini index, Bonferroni index, and Absolute Lorenz index are some popular indices of inequality showing different features of inequality measurement. In general simple random sampling procedure is commonly used to estimate the inequality indices and their related inference. The key condition that the samples must be drawn via simple random sampling procedure though makes calculations much simpler but this assumption is often violated in practice as the data does not always yield simple random ...

A probability measure for random surfaces of arbitrary genus and bosonic strings in 4 dimensions

International Nuclear Information System (INIS)

Albeverio, S.; Hoeegh-Krohn, R.; Paycha, S.; Scarlatti, S.

1989-01-01

We define a probability measure describing random surfaces in R D , 3≤D≤13, parametrized by compact Riemann surfaces of arbitrary genus. The measure involves the path space measure for scalar fields with exponential interaction in 2 space time dimensions. We show that it gives a mathematical realization of Polyakov's heuristic measure for bosonic strings. (orig.)

Nonparametric indices of dependence between components for inhomogeneous multivariate random measures and marked sets

OpenAIRE

van Lieshout, Maria Nicolette Margaretha

2018-01-01

We propose new summary statistics to quantify the association between the components in coverage-reweighted moment stationary multivariate random sets and measures. They are defined in terms of the coverage-reweighted cumulant densities and extend classic functional statistics for stationary random closed sets. We study the relations between these statistics and evaluate them explicitly for a range of models. Unbiased estimators are given for all statistics and applied to simulated examples a...

Reporting of Positive Results in Randomized Controlled Trials of Mindfulness-Based Mental Health Interventions.

Directory of Open Access Journals (Sweden)

Stephanie Coronado-Montoya

Full Text Available A large proportion of mindfulness-based therapy trials report statistically significant results, even in the context of very low statistical power. The objective of the present study was to characterize the reporting of "positive" results in randomized controlled trials of mindfulness-based therapy. We also assessed mindfulness-based therapy trial registrations for indications of possible reporting bias and reviewed recent systematic reviews and meta-analyses to determine whether reporting biases were identified.CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS databases were searched for randomized controlled trials of mindfulness-based therapy. The number of positive trials was described and compared to the number that might be expected if mindfulness-based therapy were similarly effective compared to individual therapy for depression. Trial registries were searched for mindfulness-based therapy registrations. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS were also searched for mindfulness-based therapy systematic reviews and meta-analyses.108 (87% of 124 published trials reported ≥1 positive outcome in the abstract, and 109 (88% concluded that mindfulness-based therapy was effective, 1.6 times greater than the expected number of positive trials based on effect size d = 0.55 (expected number positive trials = 65.7. Of 21 trial registrations, 13 (62% remained unpublished 30 months post-trial completion. No trial registrations adequately specified a single primary outcome measure with time of assessment. None of 36 systematic reviews and meta-analyses concluded that effect estimates were overestimated due to reporting biases.The proportion of mindfulness-based therapy trials with statistically significant results may overstate what would occur in practice.

Intensified follow-up in colorectal cancer patients using frequent Carcino-Embryonic Antigen (CEA) measurements and CEA-triggered imaging : Results of the randomized "CEAwatch" trial

NARCIS (Netherlands)

Verberne, C. J.; Zhan, Z.; van den Heuvel, E.; Grossmann, I.; Doornbos, P. M.; Havenga, K.; Manusama, E.; Klaase, J.; van der Mijle, H. C. J.; Lamme, B.; Bosscha, K.; Baas, P.; van Ooijen, B.; Nieuwenhuijzen, G.; Marinelli, A.; van der Zaag, E.; Wasowicz, D.; de Bock, G. H.; Wiggers, T.

Aim: The value of frequent Carcino-Embryonic Antigen (CEA) measurements and CEA-triggered imaging for detecting recurrent disease in colorectal cancer (CRC) patients was investigated in search for an evidence-based follow-up protocol. Methods: This is a randomized-controlled multicenter prospective

Non-Markovianity Measure Based on Brukner–Zeilinger Invariant Information for Unital Quantum Dynamical Maps

International Nuclear Information System (INIS)

He Zhi; Zhu Lie-Qiang; Li Li

2017-01-01

A non-Markovianity measure based on Brukner–Zeilinger invariant information to characterize non-Markovian effect of open systems undergoing unital dynamical maps is proposed. The method takes advantage of non-increasing property of the Brukner–Zeilinger invariant information under completely positive and trace-preserving unital maps. The simplicity of computing the Brukner–Zeilinger invariant information is the advantage of the proposed measure because of mainly depending on the purity of quantum state. The measure effectively captures the characteristics of non-Markovianity of unital dynamical maps. As some concrete application, we consider two typical non-Markovian noise channels, i.e., the phase damping channel and the random unitary channel to show the sensitivity of the proposed measure. By investigation, we find that the conditions of detecting the non-Markovianity for the phase damping channel are consistent with the results of existing measures for non-Markovianity, i.e., information flow, divisibility and quantum mutual information. However, for the random unitary channel non-Markovian conditions are same to that of the information flow, but is different from that of the divisibility and quantum mutual information. (paper)

Random laser based on Rhodamine 6G (Rh6G doped poly(methyl methacrylate (PMMA films coating on ZnO nanorods synthesized by hydrothermal oxidation

Directory of Open Access Journals (Sweden)

Hua Zhang

Full Text Available Random laser based on Rh6G doped PMMA thin films coating on ZnO nanorods synthesized by a simple hydrothermal oxidation method has been demonstrated. This kind of random laser medium is based on waveguide structure consisting of ZnO nanorods, Rh6G doped PMMA film and air. By controlling the time of hydrothermal oxidation reaction, wheat-like and hexagonal prism ZnO nanorods have been successfully fabricated. The emission spectra of these gain mediums based on different ZnO nanorods are different. The one based on wheat-like ZnO nanorods mainly exhibits amplified spontaneous emission, and the other one based on hexagonal prism ZnO nanorods shows random laser emission. The threshold of the random laser medium is about 73.8 μJ/pulse, and the full width at half maximum (FWHM is around 2.1 nm. The emission spectra measured at different detecting angles reveal that the output direction is strongly confined in ±30° by the waveguide effect. Our experiments demonstrate a promising method to achieve organic random laser medium. Keywords: Random laser, ZnO nanorods, Hydrothermal oxidation, Rhodamine 6G (Rh6G, Poly(methyl methacrylate (PMMA

FOG Random Drift Signal Denoising Based on the Improved AR Model and Modified Sage-Husa Adaptive Kalman Filter.

Science.gov (United States)

Sun, Jin; Xu, Xiaosu; Liu, Yiting; Zhang, Tao; Li, Yao

2016-07-12

In order to reduce the influence of fiber optic gyroscope (FOG) random drift error on inertial navigation systems, an improved auto regressive (AR) model is put forward in this paper. First, based on real-time observations at each restart of the gyroscope, the model of FOG random drift can be established online. In the improved AR model, the FOG measured signal is employed instead of the zero mean signals. Then, the modified Sage-Husa adaptive Kalman filter (SHAKF) is introduced, which can directly carry out real-time filtering on the FOG signals. Finally, static and dynamic experiments are done to verify the effectiveness. The filtering results are analyzed with Allan variance. The analysis results show that the improved AR model has high fitting accuracy and strong adaptability, and the minimum fitting accuracy of single noise is 93.2%. Based on the improved AR(3) model, the denoising method of SHAKF is more effective than traditional methods, and its effect is better than 30%. The random drift error of FOG is reduced effectively, and the precision of the FOG is improved.

A Fast Reactive Power Optimization in Distribution Network Based on Large Random Matrix Theory and Data Analysis

Directory of Open Access Journals (Sweden)

Wanxing Sheng

2016-05-01

Full Text Available In this paper, a reactive power optimization method based on historical data is investigated to solve the dynamic reactive power optimization problem in distribution network. In order to reflect the variation of loads, network loads are represented in a form of random matrix. Load similarity (LS is defined to measure the degree of similarity between the loads in different days and the calculation method of the load similarity of load random matrix (LRM is presented. By calculating the load similarity between the forecasting random matrix and the random matrix of historical load, the historical reactive power optimization dispatching scheme that most matches the forecasting load can be found for reactive power control usage. The differences of daily load curves between working days and weekends in different seasons are considered in the proposed method. The proposed method is tested on a standard 14 nodes distribution network with three different types of load. The computational result demonstrates that the proposed method for reactive power optimization is fast, feasible and effective in distribution network.

A Bidirectional Generalized Synchronization Theorem-Based Chaotic Pseudo-random Number Generator

Directory of Open Access Journals (Sweden)

Han Shuangshuang

2013-07-01

Full Text Available Based on a bidirectional generalized synchronization theorem for discrete chaos system, this paper introduces a new 5-dimensional bidirectional generalized chaos synchronization system (BGCSDS, whose prototype is a novel chaotic system introduced in [12]. Numerical simulation showed that two pair variables of the BGCSDS achieve generalized chaos synchronization via a transform H.A chaos-based pseudo-random number generator (CPNG was designed by the new BGCSDS. Using the FIPS-140-2 tests issued by the National Institute of Standard and Technology (NIST verified the randomness of the 1000 binary number sequences generated via the CPNG and the RC4 algorithm respectively. The results showed that all the tested sequences passed the FIPS-140-2 tests. The confidence interval analysis showed the statistical properties of the randomness of the sequences generated via the CPNG and the RC4 algorithm do not have significant differences.

Random Walks on Homeo( S 1)

Science.gov (United States)

Malicet, Dominique

2017-12-01

In this paper, we study random walks {g_n=f_{n-1}\\ldots f_0} on the group Homeo ( S 1) of the homeomorphisms of the circle, where the homeomorphisms f k are chosen randomly, independently, with respect to a same probability measure {ν}. We prove that under the only condition that there is no probability measure invariant by {ν}-almost every homeomorphism, the random walk almost surely contracts small intervals. It generalizes what has been known on this subject until now, since various conditions on {ν} were imposed in order to get the phenomenon of contractions. Moreover, we obtain the surprising fact that the rate of contraction is exponential, even in the lack of assumptions of smoothness on the f k 's. We deduce various dynamical consequences on the random walk ( g n ): finiteness of ergodic stationary measures, distribution of the trajectories, asymptotic law of the evaluations, etc. The proof of the main result is based on a modification of the Ávila-Viana's invariance principle, working for continuous cocycles on a space fibred in circles.

Effects of mobile phone-based app learning compared to computer-based web learning on nursing students: pilot randomized controlled trial.

Science.gov (United States)

Lee, Myung Kyung

2015-04-01

This study aimed to determine the effect of mobile-based discussion versus computer-based discussion on self-directed learning readiness, academic motivation, learner-interface interaction, and flow state. This randomized controlled trial was conducted at one university. Eighty-six nursing students who were able to use a computer, had home Internet access, and used a mobile phone were recruited. Participants were randomly assigned to either the mobile phone app-based discussion group (n = 45) or a computer web-based discussion group (n = 41). The effect was measured at before and after an online discussion via self-reported surveys that addressed academic motivation, self-directed learning readiness, time distortion, learner-learner interaction, learner-interface interaction, and flow state. The change in extrinsic motivation on identified regulation in the academic motivation (p = 0.011) as well as independence and ability to use basic study (p = 0.047) and positive orientation to the future in self-directed learning readiness (p = 0.021) from pre-intervention to post-intervention was significantly more positive in the mobile phone app-based group compared to the computer web-based discussion group. Interaction between learner and interface (p = 0.002), having clear goals (p = 0.012), and giving and receiving unambiguous feedback (p = 0.049) in flow state was significantly higher in the mobile phone app-based discussion group than it was in the computer web-based discussion group at post-test. The mobile phone might offer more valuable learning opportunities for discussion teaching and learning methods in terms of self-directed learning readiness, academic motivation, learner-interface interaction, and the flow state of the learning process compared to the computer.

Unbiased All-Optical Random-Number Generator

Science.gov (United States)

Steinle, Tobias; Greiner, Johannes N.; Wrachtrup, Jörg; Giessen, Harald; Gerhardt, Ilja

2017-10-01

The generation of random bits is of enormous importance in modern information science. Cryptographic security is based on random numbers which require a physical process for their generation. This is commonly performed by hardware random-number generators. These often exhibit a number of problems, namely experimental bias, memory in the system, and other technical subtleties, which reduce the reliability in the entropy estimation. Further, the generated outcome has to be postprocessed to "iron out" such spurious effects. Here, we present a purely optical randomness generator, based on the bistable output of an optical parametric oscillator. Detector noise plays no role and postprocessing is reduced to a minimum. Upon entering the bistable regime, initially the resulting output phase depends on vacuum fluctuations. Later, the phase is rigidly locked and can be well determined versus a pulse train, which is derived from the pump laser. This delivers an ambiguity-free output, which is reliably detected and associated with a binary outcome. The resulting random bit stream resembles a perfect coin toss and passes all relevant randomness measures. The random nature of the generated binary outcome is furthermore confirmed by an analysis of resulting conditional entropies.

A Table-Based Random Sampling Simulation for Bioluminescence Tomography

Directory of Open Access Journals (Sweden)

Xiaomeng Zhang

2006-01-01

Full Text Available As a popular simulation of photon propagation in turbid media, the main problem of Monte Carlo (MC method is its cumbersome computation. In this work a table-based random sampling simulation (TBRS is proposed. The key idea of TBRS is to simplify multisteps of scattering to a single-step process, through randomly table querying, thus greatly reducing the computing complexity of the conventional MC algorithm and expediting the computation. The TBRS simulation is a fast algorithm of the conventional MC simulation of photon propagation. It retained the merits of flexibility and accuracy of conventional MC method and adapted well to complex geometric media and various source shapes. Both MC simulations were conducted in a homogeneous medium in our work. Also, we present a reconstructing approach to estimate the position of the fluorescent source based on the trial-and-error theory as a validation of the TBRS algorithm. Good agreement is found between the conventional MC simulation and the TBRS simulation.

The effect of community-based health management on the health of the elderly: a randomized controlled trial from China

Directory of Open Access Journals (Sweden)

Chao Jianqian

2012-12-01

Full Text Available Abstract Background An aging population poses significant challenges to health care in China. Health management has been implemented to reduce the costs of care, raise health service utilization, increase health knowledge and improve quality of life. Several studies have tried to verify the effectiveness of health management in achieving these goals worldwide. However, there have been insufficient randomized control trials (RCTs to draw reliable conclusions. The few small-scale studies conducted in China include mostly the general population rather than the elderly. Our study is designed to evaluate the impact of community-based health management on the health of the elderly through an RCT in Nanjing, China. Methods Two thousand four hundred participants, aged 60 or older and who gave informed consent, were randomly allocated 1:1 into management and control groups, the randomization schedule was concealed from community health service center staff until allocation. Community-based health management was applied in the former while the latter was only given usual care. After 18 months, three categories of variables (subjective grading health indices, objective health indices and health service utilization were measured based on a questionnaire, clinical monitoring and diagnostic measurements. Differences between the two groups were assessed before and after the intervention and analyzed with t-test, χ2-test, and multiple regression analysis. Results Compared with the control group, the management group demonstrated improvement on the following variables (P Conclusion Community-based health management improved both subjective grading health indices, objective health indices and decreased the number of outpatient clinic visits, demonstrating effectiveness in improving elderly health. Trial registration ChiCTR-OCH-11001716

Post-processing Free Quantum Random Number Generator Based on Avalanche Photodiode Array

International Nuclear Information System (INIS)

Li Yang; Liao Sheng-Kai; Liang Fu-Tian; Shen Qi; Liang Hao; Peng Cheng-Zhi

2016-01-01

Quantum random number generators adopting single photon detection have been restricted due to the non-negligible dead time of avalanche photodiodes (APDs). We propose a new approach based on an APD array to improve the generation rate of random numbers significantly. This method compares the detectors' responses to consecutive optical pulses and generates the random sequence. We implement a demonstration experiment to show its simplicity, compactness and scalability. The generated numbers are proved to be unbiased, post-processing free, ready to use, and their randomness is verified by using the national institute of standard technology statistical test suite. The random bit generation efficiency is as high as 32.8% and the potential generation rate adopting the 32 × 32 APD array is up to tens of Gbits/s. (paper)

A true random number generator based on mouse movement and chaotic cryptography

International Nuclear Information System (INIS)

Hu Yue; Liao Xiaofeng; Wong, Kwok-wo; Zhou Qing

2009-01-01

True random number generators are in general more secure than pseudo random number generators. In this paper, we propose a novel true random number generator which generates a 256-bit random number by computer mouse movement. It is cheap, convenient and universal for personal computers. To eliminate the effect of similar movement patterns generated by the same user, three chaos-based approaches, namely, discretized 2D chaotic map permutation, spatiotemporal chaos and 'MASK' algorithm, are adopted to post-process the captured mouse movements. Random bits generated by three users are tested using NIST statistical tests. Both the spatiotemporal chaos approach and the 'MASK' algorithm pass the tests successfully. However, the latter has a better performance in terms of efficiency and effectiveness and so is more practical for common personal computer applications.

Basic properties of the current-current correlation measure for random Schroedinger operators

International Nuclear Information System (INIS)

Hislop, Peter D.; Lenoble, Olivier

2006-01-01

The current-current correlation measure plays a crucial role in the theory of conductivity for disordered systems. We prove a Pastur-Shubin-type formula for the current-current correlation measure expressing it as a thermodynamic limit for random Schroedinger operators on the lattice and the continuum. We prove that the limit is independent of the self-adjoint boundary conditions and independent of a large family of expanding regions. We relate this finite-volume definition to the definition obtained by using the infinite-volume operators and the trace-per-unit volume

Quantitative time domain analysis of lifetime-based Förster resonant energy transfer measurements with fluorescent proteins: Static random isotropic fluorophore orientation distributions

DEFF Research Database (Denmark)

Alexandrov, Yuriy; Nikolic, Dino Solar; Dunsby, Christopher

2018-01-01

Förster resonant energy transfer (FRET) measurements are widely used to obtain information about molecular interactions and conformations through the dependence of FRET efficiency on the proximity of donor and acceptor fluorophores. Fluorescence lifetime measurements can provide quantitative...... into new software for fitting donor emission decay profiles. Calculated FRET parameters, including molar population fractions, are compared for the analysis of simulated and experimental FRET data under the assumption of static and dynamic fluorophores and the intermediate regimes between fully dynamic...... analysis of FRET efficiency and interacting population fraction. Many FRET experiments exploit the highly specific labelling of genetically expressed fluorescent proteins, applicable in live cells and organisms. Unfortunately, the typical assumption of fast randomization of fluorophore orientations...

An integrable low-cost hardware random number generator

Science.gov (United States)

Ranasinghe, Damith C.; Lim, Daihyun; Devadas, Srinivas; Jamali, Behnam; Zhu, Zheng; Cole, Peter H.

2005-02-01

A hardware random number generator is different from a pseudo-random number generator; a pseudo-random number generator approximates the assumed behavior of a real hardware random number generator. Simple pseudo random number generators suffices for most applications, however for demanding situations such as the generation of cryptographic keys, requires an efficient and a cost effective source of random numbers. Arbiter-based Physical Unclonable Functions (PUFs) proposed for physical authentication of ICs exploits statistical delay variation of wires and transistors across integrated circuits, as a result of process variations, to build a secret key unique to each IC. Experimental results and theoretical studies show that a sufficient amount of variation exits across IC"s. This variation enables each IC to be identified securely. It is possible to exploit the unreliability of these PUF responses to build a physical random number generator. There exists measurement noise, which comes from the instability of an arbiter when it is in a racing condition. There exist challenges whose responses are unpredictable. Without environmental variations, the responses of these challenges are random in repeated measurements. Compared to other physical random number generators, the PUF-based random number generators can be a compact and a low-power solution since the generator need only be turned on when required. A 64-stage PUF circuit costs less than 1000 gates and the circuit can be implemented using a standard IC manufacturing processes. In this paper we have presented a fast and an efficient random number generator, and analysed the quality of random numbers produced using an array of tests used by the National Institute of Standards and Technology to evaluate the randomness of random number generators designed for cryptographic applications.

Random fiber lasers based on artificially controlled backscattering fibers

Science.gov (United States)

Chen, Daru; Wang, Xiaoliang; She, Lijuan; Qiang, Zexuan; Yu, Zhangwei

2017-10-01

The random fiber laser (RFL) which is a milestone in laser physics and nonlinear optics, has attracted considerable attention recently. Most previous RFLs are based on distributed feedback of Rayleigh scattering amplified through stimulated Raman/Brillouin scattering effect in single mode fibers, which required long-distance (tens of kilometers) single mode fibers and high threshold up to watt-level due to the extremely small Rayleigh scattering coefficient of the fiber. We proposed and demonstrated a half-open cavity RFL based on a segment of a artificially controlled backscattering SMF(ACB-SMF) with a length of 210m, 310m or 390m. A fiber Bragg grating with the central wavelength of 1530nm and a segment of ACB-SMF forms the half-open cavity. The proposed RFL achieves the threshold of 25mW, 30mW and 30mW, respectively. Random lasing at the wavelength of 1530nm and the extinction ratio of 50dB is achieved when a segment of 5m EDF is pumped by a 980nm LD in the RFL. Another half-open cavity RFL based on a segment of a artificially controlled backscattering EDF(ACBS-EDF) is also demonstrated without an ACB-SMF. The 3m ACB-EDF is fabricated by using the femtosecond laser with pulse energy of 0.34mJ which introduces about 50 reflectors in the EDF. Random lasing at the wavelength of 1530nm is achieved with the output power of 7.5mW and the efficiency of 1.88%. Two novel RFLs with much short cavities have been achieved with low threshold and high efficiency.

Randomized Controlled Trial of SuperBetter, a Smartphone-Based/Internet-Based Self-Help Tool to Reduce Depressive Symptoms.

Science.gov (United States)

Roepke, Ann Marie; Jaffee, Sara R; Riffle, Olivia M; McGonigal, Jane; Broome, Rose; Maxwell, Bez

2015-06-01

Technological advances have sparked the development of computer- and smartphone-based self-help programs for depressed people, but these programs' efficacy is uncertain. This randomized controlled trial evaluated an intervention called SuperBetter (SB), which is accessed via smartphone and/or the SB Web site. Online, we recruited 283 adult iPhone(®) (Apple, Cupertino, CA) users with significant depression symptoms according to the Center for Epidemiological Studies Depression questionnaire (CES-D). They were randomly assigned to one of three conditions: (a) a version of SB using cognitive-behavioral therapy and positive psychotherapy strategies to target depression (CBT-PPT SB); (b) a general SB version focused on self-esteem and acceptance (General SB); or (c) a waiting list control group (WL). The two SB groups were instructed to use SB for 10 minutes daily for 1 month. All participants completed psychological distress and well-being measures online every 2 weeks through follow-up. An intent-to-treat analysis was conducted using hierarchical linear modeling. As hypothesized, SB participants achieved greater reductions in CES-D scores than WL participants by posttest (Cohen's d=0.67) and by follow-up (d=1.05). Contrary to prediction, CBT-PPT SB did not perform better than General SB; both versions of SB were more effective than the WL control. Differences between SB versions favored General SB but were not statistically significant. These large effect sizes should be interpreted cautiously in light of high attrition rates and the motivated, self-selected sample. Nonetheless, smartphone-based/Internet-based self-help may play an important role in treating depression.

Improving Pediatric Basic Life Support Performance Through Blended Learning With Web-Based Virtual Patients: Randomized Controlled Trial.

Science.gov (United States)

Lehmann, Ronny; Thiessen, Christiane; Frick, Barbara; Bosse, Hans Martin; Nikendei, Christoph; Hoffmann, Georg Friedrich; Tönshoff, Burkhard; Huwendiek, Sören

2015-07-02

E-learning and blended learning approaches gain more and more popularity in emergency medicine curricula. So far, little data is available on the impact of such approaches on procedural learning and skill acquisition and their comparison with traditional approaches. This study investigated the impact of a blended learning approach, including Web-based virtual patients (VPs) and standard pediatric basic life support (PBLS) training, on procedural knowledge, objective performance, and self-assessment. A total of 57 medical students were randomly assigned to an intervention group (n=30) and a control group (n=27). Both groups received paper handouts in preparation of simulation-based PBLS training. The intervention group additionally completed two Web-based VPs with embedded video clips. Measurements were taken at randomization (t0), after the preparation period (t1), and after hands-on training (t2). Clinical decision-making skills and procedural knowledge were assessed at t0 and t1. PBLS performance was scored regarding adherence to the correct algorithm, conformance to temporal demands, and the quality of procedural steps at t1 and t2. Participants' self-assessments were recorded in all three measurements. Procedural knowledge of the intervention group was significantly superior to that of the control group at t1. At t2, the intervention group showed significantly better adherence to the algorithm and temporal demands, and better procedural quality of PBLS in objective measures than did the control group. These aspects differed between the groups even at t1 (after VPs, prior to practical training). Self-assessments differed significantly only at t1 in favor of the intervention group. Training with VPs combined with hands-on training improves PBLS performance as judged by objective measures.

Web-Based Tools for Educating Caregivers About Childhood Fever: A Randomized Controlled Trial.

Science.gov (United States)

Hart, Lara; Nedadur, Rashmi; Reardon, Jaime; Sirizzotti, Natalie; Poonai, Caroline; Speechley, Kathy N; Loftus, Jay; Miller, Michael; Salvadori, Marina; Spadafora, Amanda; Poonai, Naveen

2016-10-04

Fever is a common reason for an emergency department visit and misconceptions abound. We assessed the effectiveness of an interactive Web-based module (WBM), read-only Web site (ROW), and written and verbal information (standard of care [SOC]) to educate caregivers about fever in their children. Caregivers in the emergency department were randomized to a WBM, ROW, or SOC. Primary outcome was the gain score on a novel questionnaire testing knowledge surrounding measurement and management of fever. Secondary outcome was caregiver satisfaction with the interventions. There were 77, 79, and 77 participants in the WBM, ROW, and SOC groups, respectively. With a maximum of 33 points, Web-based interventions were associated with a significant mean (SD) pretest to immediate posttest gain score of 3.5 (4.2) for WBM (P ROW > SOC (P Web-based interventions are associated with significant improvements in caregiver knowledge about fever and high caregiver satisfaction. These interventions should be used to educate caregivers pending the demonstration of improved patient-centered outcomes.

Mindfulness-based cognitive therapy (MBCT) for multiple chemical sensitivity (MCS): Results from a randomized controlled trial with 1-year follow-up

DEFF Research Database (Denmark)

Hauge, Christian Riise; Rasmussen, Alice; Piet, Jacob

2015-01-01

the effects of mindfulness-based cognitive therapy (MBCT) for individuals with MCS. Methods The intention-to-treat sample (ITT) included 69 individuals who had been randomized to either MBCT or treatment as usual (TAU). The primary outcome measure was the Quick Environmental Exposure and Sensitivity Inventory...

Telephone based cognitive behavioral therapy targeting major depression among urban dwelling, low income people living with HIV/AIDS: results of a randomized controlled trial.

Science.gov (United States)

Himelhoch, Seth; Medoff, Deborah; Maxfield, Jennifer; Dihmes, Sarah; Dixon, Lisa; Robinson, Charles; Potts, Wendy; Mohr, David C

2013-10-01

This pilot randomized controlled trial evaluated a previously developed manualized telephone based cognitive behavioral therapy (T-CBT) intervention compared to face-to-face (f2f) therapy among low-income, urban dwelling HIV infected depressed individuals. The primary outcome was the reduction of depressive symptoms as measured by the Hamliton rating scale for depression scale. The secondary outcome was adherence to HAART as measured by random telephone based pill counts. Outcome measures were collected by trained research assistants masked to treatment allocation. Analysis was based on intention-to-treat. Thirty-four participants met eligibility criteria and were randomly assigned to receive T-CBT (n = 16) or f2f (n = 18). There was no statistically significant difference in depression treatment outcomes comparing f2f to T-CBT. Within group evaluation demonstrated that both the T-CBT and the f2f psychotherapy groups resulted in significant reductions in depressive symptoms. Those who received the T-CBT were significantly more likely to maintain their adherence to antiretroviral medication compared to the f2f treatment. None of the participants discontinued treatment due to adverse events. T-CBT can be delivered to low-income, urban dwelling HIV infected depressed individuals resulting in significant reductions in depression symptoms and improved adherence to antiretroviral medication. Clinical Trial.gov identifier: NCT01055158.

A randomized controlled trial of aquatic and land-based exercise in patients with knee osteoarthritis

DEFF Research Database (Denmark)

Lund, H.; Weile, U.; Christensen, R.

2008-01-01

patients reported adverse events (i.e. discomfort) in land-based exercise, while only 3 reported adverse events in the aquatic exercise. Conclusion: Only land-based exercise showed some improvement in pain and muscle strength compared with the control group, while no clinical benefits were detectable after......Objective: To compare the efficacy of aquatic exercise and a land-based exercise programme vs control in patients with knee osteoarthritis. Methods: Primary outcome was change in pain, and in addition Knee Injury and Osteoarthritis Outcome Score questionnaire (KOOS). Standing balance and strength...... was also measured after and at 3-month follow-up. Seventy-nine patients (62 women), with a mean age of 68 years (age range 40-89 years) were randomized to aquatic exercise (n = 27), land-based exercise (n = 25) or control (n = 27). Results: No effect was observed immediately after exercise cessation (8...

Entropy Characterization of Random Network Models

Directory of Open Access Journals (Sweden)

Pedro J. Zufiria

2017-06-01

Full Text Available This paper elaborates on the Random Network Model (RNM as a mathematical framework for modelling and analyzing the generation of complex networks. Such framework allows the analysis of the relationship between several network characterizing features (link density, clustering coefficient, degree distribution, connectivity, etc. and entropy-based complexity measures, providing new insight on the generation and characterization of random networks. Some theoretical and computational results illustrate the utility of the proposed framework.

Cellular Automata-Based Parallel Random Number Generators Using FPGAs

Directory of Open Access Journals (Sweden)

David H. K. Hoe

2012-01-01

Full Text Available Cellular computing represents a new paradigm for implementing high-speed massively parallel machines. Cellular automata (CA, which consist of an array of locally connected processing elements, are a basic form of a cellular-based architecture. The use of field programmable gate arrays (FPGAs for implementing CA accelerators has shown promising results. This paper investigates the design of CA-based pseudo-random number generators (PRNGs using an FPGA platform. To improve the quality of the random numbers that are generated, the basic CA structure is enhanced in two ways. First, the addition of a superrule to each CA cell is considered. The resulting self-programmable CA (SPCA uses the superrule to determine when to make a dynamic rule change in each CA cell. The superrule takes its inputs from neighboring cells and can be considered itself a second CA working in parallel with the main CA. When implemented on an FPGA, the use of lookup tables in each logic cell removes any restrictions on how the super-rules should be defined. Second, a hybrid configuration is formed by combining a CA with a linear feedback shift register (LFSR. This is advantageous for FPGA designs due to the compactness of the LFSR implementations. A standard software package for statistically evaluating the quality of random number sequences known as Diehard is used to validate the results. Both the SPCA and the hybrid CA/LFSR were found to pass all the Diehard tests.

Coordinate based random effect size meta-analysis of neuroimaging studies.

Science.gov (United States)

Tench, C R; Tanasescu, Radu; Constantinescu, C S; Auer, D P; Cottam, W J

2017-06-01

Low power in neuroimaging studies can make them difficult to interpret, and Coordinate based meta-analysis (CBMA) may go some way to mitigating this issue. CBMA has been used in many analyses to detect where published functional MRI or voxel-based morphometry studies testing similar hypotheses report significant summary results (coordinates) consistently. Only the reported coordinates and possibly t statistics are analysed, and statistical significance of clusters is determined by coordinate density. Here a method of performing coordinate based random effect size meta-analysis and meta-regression is introduced. The algorithm (ClusterZ) analyses both coordinates and reported t statistic or Z score, standardised by the number of subjects. Statistical significance is determined not by coordinate density, but by a random effects meta-analyses of reported effects performed cluster-wise using standard statistical methods and taking account of censoring inherent in the published summary results. Type 1 error control is achieved using the false cluster discovery rate (FCDR), which is based on the false discovery rate. This controls both the family wise error rate under the null hypothesis that coordinates are randomly drawn from a standard stereotaxic space, and the proportion of significant clusters that are expected under the null. Such control is necessary to avoid propagating and even amplifying the very issues motivating the meta-analysis in the first place. ClusterZ is demonstrated on both numerically simulated data and on real data from reports of grey matter loss in multiple sclerosis (MS) and syndromes suggestive of MS, and of painful stimulus in healthy controls. The software implementation is available to download and use freely. Copyright © 2017 Elsevier Inc. All rights reserved.

Random pulse generator

International Nuclear Information System (INIS)

Guo Ya'nan; Jin Dapeng; Zhao Dixin; Liu Zhen'an; Qiao Qiao; Chinese Academy of Sciences, Beijing

2007-01-01

Due to the randomness of radioactive decay and nuclear reaction, the signals from detectors are random in time. But normal pulse generator generates periodical pulses. To measure the performances of nuclear electronic devices under random inputs, a random generator is necessary. Types of random pulse generator are reviewed, 2 digital random pulse generators are introduced. (authors)

Video-based measurements for wireless capsule endoscope tracking

International Nuclear Information System (INIS)

Spyrou, Evaggelos; Iakovidis, Dimitris K

2014-01-01

The wireless capsule endoscope is a swallowable medical device equipped with a miniature camera enabling the visual examination of the gastrointestinal (GI) tract. It wirelessly transmits thousands of images to an external video recording system, while its location and orientation are being tracked approximately by external sensor arrays. In this paper we investigate a video-based approach to tracking the capsule endoscope without requiring any external equipment. The proposed method involves extraction of speeded up robust features from video frames, registration of consecutive frames based on the random sample consensus algorithm, and estimation of the displacement and rotation of interest points within these frames. The results obtained by the application of this method on wireless capsule endoscopy videos indicate its effectiveness and improved performance over the state of the art. The findings of this research pave the way for a cost-effective localization and travel distance measurement of capsule endoscopes in the GI tract, which could contribute in the planning of more accurate surgical interventions. (paper)

Video-based measurements for wireless capsule endoscope tracking

Science.gov (United States)

Spyrou, Evaggelos; Iakovidis, Dimitris K.

2014-01-01

The wireless capsule endoscope is a swallowable medical device equipped with a miniature camera enabling the visual examination of the gastrointestinal (GI) tract. It wirelessly transmits thousands of images to an external video recording system, while its location and orientation are being tracked approximately by external sensor arrays. In this paper we investigate a video-based approach to tracking the capsule endoscope without requiring any external equipment. The proposed method involves extraction of speeded up robust features from video frames, registration of consecutive frames based on the random sample consensus algorithm, and estimation of the displacement and rotation of interest points within these frames. The results obtained by the application of this method on wireless capsule endoscopy videos indicate its effectiveness and improved performance over the state of the art. The findings of this research pave the way for a cost-effective localization and travel distance measurement of capsule endoscopes in the GI tract, which could contribute in the planning of more accurate surgical interventions.

Home-based balance training using the Wii balance board: a randomized, crossover pilot study in multiple sclerosis.

Science.gov (United States)

Prosperini, Luca; Fortuna, Deborah; Giannì, Costanza; Leonardi, Laura; Marchetti, Maria Rita; Pozzilli, Carlo

2013-01-01

To evaluate the effectiveness of a home-based rehabilitation of balance using the Nintendo Wii Balance Board System (WBBS) in patients affected by multiple sclerosis (MS). In this 24-week, randomized, 2-period crossover pilot study, 36 patients having an objective balance disorder were randomly assigned in a 1:1 ratio to 2 counterbalanced arms. Group A started a 12-week period of home-based WBBS training followed by a 12-week period without any intervention; group B received the treatment in reverse order. As endpoints, we considered the mean difference (compared with baseline) in force platform measures (i.e., the displacement of body center of pressure in 30 seconds), 4-step square test (FSST), 25-foot timed walking test (25-FWT), and 29-item MS Impact Scale (MSIS-29), as evaluated after 12 weeks and at the end of the 24-week study period. The 2 groups did not differ in baseline characteristics. Repeated-measures analyses of variance showed significant time × treatment effects, indicating that WBBS was effective in ameliorating force platform measures (F = 4.608, P = .016), FSST (F = 3.745, P = .034), 25-FWT (F = 3.339, P = .048), and MSIS-29 (F = 4.282, P = .023). Five adverse events attributable to the WBSS training (knee or low back pain) were recorded, but only 1 patient had to retire from the study. A home-based WBBS training might potentially provide an effective, engaging, balance rehabilitation solution for people with MS. However, the risk of WBBS training-related injuries should be carefully balanced with benefits. Further studies, including cost-effectiveness analyses, are warranted to establish whether WBBS may be useful in the home setting.

How to Measure Motivational Interviewing Fidelity in Randomized Controlled Trials: Practical Recommendations.

Science.gov (United States)

Jelsma, Judith G M; Mertens, Vera-Christina; Forsberg, Lisa; Forsberg, Lars

2015-07-01

Many randomized controlled trials in which motivational interviewing (MI) is a key intervention make no provision for the assessment of treatment fidelity. This methodological shortcoming makes it impossible to distinguish between high- and low-quality MI interventions, and, consequently, to know whether MI provision has contributed to any intervention effects. This article makes some practical recommendations for the collection, selection, coding and reporting of MI fidelity data, as measured using the Motivational Interviewing Treatment Integrity Code. We hope that researchers will consider these recommendations and include MI fidelity measures in future studies. Copyright © 2015 Elsevier Inc. All rights reserved.

A randomized controlled trial of smartphone-based mindfulness training for smoking cessation: a study protocol.

Science.gov (United States)

Garrison, Kathleen A; Pal, Prasanta; Rojiani, Rahil; Dallery, Jesse; O'Malley, Stephanie S; Brewer, Judson A

2015-04-14

Tobacco use is responsible for the death of about 1 in 10 individuals worldwide. Mindfulness training has shown preliminary efficacy as a behavioral treatment for smoking cessation. Recent advances in mobile health suggest advantages to smartphone-based smoking cessation treatment including smartphone-based mindfulness training. This study evaluates the efficacy of a smartphone app-based mindfulness training program for improving smoking cessation rates at 6-months follow-up. A two-group parallel-randomized clinical trial with allocation concealment will be conducted. Group assignment will be concealed from study researchers through to follow-up. The study will be conducted by smartphone and online. Daily smokers who are interested in quitting smoking and own a smartphone (n = 140) will be recruited through study advertisements posted online. After completion of a baseline survey, participants will be allocated randomly to the control or intervention group. Participants in both groups will receive a 22-day smartphone-based treatment program for smoking. Participants in the intervention group will receive mobile mindfulness training plus experience sampling. Participants in the control group will receive experience sampling-only. The primary outcome measure will be one-week point prevalence abstinence from smoking (at 6-months follow-up) assessed using carbon monoxide breath monitoring, which will be validated through smartphone-based video chat. This is the first intervention study to evaluate smartphone-based delivery of mindfulness training for smoking cessation. Such an intervention may provide treatment in-hand, in real-world contexts, to help individuals quit smoking. Clinicaltrials.gov NCT02134509 . Registered 7 May 2014.

Internet-based self-help treatment for depression in multiple sclerosis: study protocol of a randomized controlled trial

Directory of Open Access Journals (Sweden)

Boeschoten Rosa E

2012-09-01

Full Text Available Abstract Background Depression in MS patients is frequent but often not treated adequately. An important underlying factor may be physical limitations that preclude face-to-face contact. Internet-based treatment showed to be effective for depressive symptoms in general and could thus be a promising tool for treatment in MS. Methods/design Here, we present a study protocol to investigate the effectiveness of a 5 week Internet-based self-help problem solving treatment (PST for depressive symptoms in MS patients in a randomized controlled trial. We aim to include 166 MS patients with moderate to severe depressive symptoms who will be randomly assigned to an Internet-based intervention (with or without supportive text-messages or waiting list control group. The primary outcome is the change in depressive symptoms defined by a change in the sum score on the Beck Depression Inventory (BDI-II. Secondary outcomes will include measures of anxiety, fatigue, cognitive functioning, physical and psychological impact of MS, quality of life, problem solving skills, social support, mastery, satisfaction and compliance rate. Assessments will take place at baseline (T0, within a week after the intervention (T1, at four months (T2 and at ten months follow-up (T3: only the intervention group. The control group will be measured at the same moments in time. Analysis will be based on the intention-to-treat principle. Discussion If shown to be effective, Internet-based PST will offer new possibilities to reach and treat MS patients with depressive symptoms and to improve the quality of care. Trial Registration The Dutch Cochrane Center, NTR2772

Ellipsometry measurements of glass transition breadth in bulk films of random, block, and gradient copolymers.

Science.gov (United States)

Mok, M M; Kim, J; Marrou, S R; Torkelson, J M

2010-03-01

Bulk films of random, block and gradient copolymer systems were studied using ellipsometry to demonstrate the applicability of the numerical differentiation technique pioneered by Kawana and Jones for studying the glass transition temperature (T (g)) behavior and thermal expansivities of copolymers possessing different architectures and different levels of nanoheterogeneity. In a series of styrene/n -butyl methacrylate (S/nBMA) random copolymers, T (g) breadths were observed to increase from approximately 17( degrees ) C in styrene-rich cases to almost 30( degrees ) C in nBMA-rich cases, reflecting previous observations of significant nanoheterogeneity in PnBMA homopolymers. The derivative technique also revealed for the first time a substantial increase in glassy-state expansivity with increasing nBMA content in S/nBMA random copolymers, from 1.4x10(-4) K-1 in PS to 3.5x10(-4) K-1 in PnBMA. The first characterization of block copolymer T (g) 's and T (g) breadths by ellipsometry is given, examining the impact of nanophase-segregated copolymer structure on ellipsometric measurements of glass transition. The results show that, while the technique is effective in detecting the two T (g) 's expected in certain block copolymer systems, the details of the glass transition can become suppressed in ellipsometry measurements of a rubbery minor phase under conditions where the matrix is glassy; meanwhile, both transitions are easily discernible by differential scanning calorimetry. Finally, broad glass transition regions were measured in gradient copolymers, yielding in some cases extraordinary T (g) breadths of 69- 71( degrees ) C , factors of 4-5 larger than the T (g) breadths of related homopolymers and random copolymers. Surprisingly, one gradient copolymer demonstrated a slightly narrower T (g) breadth than the S/nBMA random copolymers with the highest nBMA content. This highlights the fact that nanoheterogeneity relevant to the glass transition response in selected

Effectiveness of a web-based intervention for injured claimants: a randomized controlled trial.

Science.gov (United States)

Elbers, Nieke A; Akkermans, Arno J; Cuijpers, Pim; Bruinvels, David J

2013-07-20

There is considerable evidence showing that injured people who are involved in a compensation process show poorer physical and mental recovery than those with similar injuries who are not involved in a compensation process. One explanation for this reduced recovery is that the legal process and the associated retraumatization are very stressful for the claimant. The aim of this study was to empower injured claimants in order to facilitate recovery. Participants were recruited by three Dutch claims settlement offices. The participants had all been injured in a traffic crash and were involved in a compensation process. The study design was a randomized controlled trial. An intervention website was developed with (1) information about the compensation process, and (2) an evidence-based, therapist-assisted problem-solving course. The control website contained a few links to already existing websites. Outcome measures were empowerment, self-efficacy, health status (including depression, anxiety, and somatic symptoms), perceived fairness, ability to work, claims knowledge and extent of burden. The outcomes were self-reported through online questionnaires and were measured four times: at baseline, and at 3, 6, and 12 months. In total, 176 participants completed the baseline questionnaire after which they were randomized into either the intervention group (n=88) or the control group (n=88). During the study, 35 participants (20%) dropped out. The intervention website was used by 55 participants (63%). The health outcomes of the intervention group were no different to those of the control group. However, the intervention group considered the received compensation to be fairer (Pwebsite was evaluated positively. Although the web-based intervention was not used enough to improve the health of injured claimants in compensation processes, it increased the perceived fairness of the compensation amount. Netherlands Trial Register NTR2360.

A pilot randomized trial teaching mindfulness-based stress reduction to traumatized youth in foster care.

Science.gov (United States)

Jee, Sandra H; Couderc, Jean-Philippe; Swanson, Dena; Gallegos, Autumn; Hilliard, Cammie; Blumkin, Aaron; Cunningham, Kendall; Heinert, Sara

2015-08-01

This article presents a pilot project implementing a mindfulness-based stress reduction program among traumatized youth in foster and kinship care over 10 weeks. Forty-two youth participated in this randomized controlled trial that used a mixed-methods (quantitative, qualitative, and physiologic) evaluation. Youth self-report measuring mental health problems, mindfulness, and stress were lower than anticipated, and the relatively short time-frame to teach these skills to traumatized youth may not have been sufficient to capture significant changes in stress as measured by electrocardiograms. Main themes from qualitative data included expressed competence in managing ongoing stress, enhanced self-awareness, and new strategies to manage stress. We share our experiences and recommendations for future research and practice, including focusing efforts on younger youth, and using community-based participatory research principles to promote engagement and co-learning. CLINICALTRIALS.GOV: Protocol Registration System ID NCT01708291. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sensitivity analysis for missing dichotomous outcome data in multi-visit randomized clinical trial with randomization-based covariance adjustment.

Science.gov (United States)

Li, Siying; Koch, Gary G; Preisser, John S; Lam, Diana; Sanchez-Kam, Matilde

2017-01-01

Dichotomous endpoints in clinical trials have only two possible outcomes, either directly or via categorization of an ordinal or continuous observation. It is common to have missing data for one or more visits during a multi-visit study. This paper presents a closed form method for sensitivity analysis of a randomized multi-visit clinical trial that possibly has missing not at random (MNAR) dichotomous data. Counts of missing data are redistributed to the favorable and unfavorable outcomes mathematically to address possibly informative missing data. Adjusted proportion estimates and their closed form covariance matrix estimates are provided. Treatment comparisons over time are addressed with Mantel-Haenszel adjustment for a stratification factor and/or randomization-based adjustment for baseline covariables. The application of such sensitivity analyses is illustrated with an example. An appendix outlines an extension of the methodology to ordinal endpoints.

Order-based representation in random networks of cortical neurons.

Directory of Open Access Journals (Sweden)

Goded Shahaf

2008-11-01

Full Text Available The wide range of time scales involved in neural excitability and synaptic transmission might lead to ongoing change in the temporal structure of responses to recurring stimulus presentations on a trial-to-trial basis. This is probably the most severe biophysical constraint on putative time-based primitives of stimulus representation in neuronal networks. Here we show that in spontaneously developing large-scale random networks of cortical neurons in vitro the order in which neurons are recruited following each stimulus is a naturally emerging representation primitive that is invariant to significant temporal changes in spike times. With a relatively small number of randomly sampled neurons, the information about stimulus position is fully retrievable from the recruitment order. The effective connectivity that makes order-based representation invariant to time warping is characterized by the existence of stations through which activity is required to pass in order to propagate further into the network. This study uncovers a simple invariant in a noisy biological network in vitro; its applicability under in vivo constraints remains to be seen.

Characterization and synthesis of random acceleration vibration specifications

NARCIS (Netherlands)

Wijker, Jacob J; Ellenbroek, Marcellinus Hermannus Maria; de Boer, Andries; Papadrakakis, M.; Lagaros, N.D.; Plevris, V.

2013-01-01

Random acceleration vibration specifications for subsystems, i.e. instruments, equipment, are most times based on measurement during acoustic noise tests on system level, i.e. a spacecraft and measured by accelerometers, placed in the neighborhood of the interface between spacecraft and subsystem.

Quantum randomness and unpredictability

Energy Technology Data Exchange (ETDEWEB)

Jaeger, Gregg [Quantum Communication and Measurement Laboratory, Department of Electrical and Computer Engineering and Division of Natural Science and Mathematics, Boston University, Boston, MA (United States)

2017-06-15

Quantum mechanics is a physical theory supplying probabilities corresponding to expectation values for measurement outcomes. Indeed, its formalism can be constructed with measurement as a fundamental process, as was done by Schwinger, provided that individual measurements outcomes occur in a random way. The randomness appearing in quantum mechanics, as with other forms of randomness, has often been considered equivalent to a form of indeterminism. Here, it is argued that quantum randomness should instead be understood as a form of unpredictability because, amongst other things, indeterminism is not a necessary condition for randomness. For concreteness, an explication of the randomness of quantum mechanics as the unpredictability of quantum measurement outcomes is provided. Finally, it is shown how this view can be combined with the recently introduced view that the very appearance of individual quantum measurement outcomes can be grounded in the Plenitude principle of Leibniz, a principle variants of which have been utilized in physics by Dirac and Gell-Mann in relation to the fundamental processes. This move provides further support to Schwinger's ''symbolic'' derivation of quantum mechanics from measurement. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

At Home Photography-Based Method for Measuring Wrist Range of Motion.

Science.gov (United States)

Trehan, Samir K; Rancy, Schneider K; Johnsen, Parker H; Hillstrom, Howard J; Lee, Steve K; Wolfe, Scott W

2017-11-01

Purpose  To determine the reliability of wrist range of motion (WROM) measurements based on digital photographs taken by patients at home compared with traditional measurements done in the office with a goniometer. Methods  Sixty-nine postoperative patients were enrolled in this study at least 3 months postoperatively. Active and passive wrist flexion/extension and radial/ulnar deviation were recorded by one of the two attending surgeons with a 1-degree resolution goniometer at the last postoperative office visit. Patients were provided an illustrated instruction sheet detailing how to take digital photographic images at home in six wrist positions (active and passive flexion/extension, and radial/ulnar deviation). Wrist position was measured from digital images by both the attending surgeons in a randomized, blinded fashion on two separate occasions greater than 2 weeks apart using the same goniometer. Reliability analysis was performed using the intraclass correlation coefficient to assess agreement between clinical and photography-based goniometry, as well as intra- and interobserver agreement. Results  Out of 69 enrolled patients, 30 (43%) patients sent digital images. Of the 180 digital photographs, only 9 (5%) were missing or deemed inadequate for WROM measurements. Agreement between clinical and photography-based measurements was "almost perfect" for passive wrist flexion/extension and "substantial" for active wrist flexion/extension and radial/ulnar deviation. Inter- and intraobserver agreement for the attending surgeons was "almost perfect" for all measurements. Discussion  This study validates a photography-based goniometry protocol allowing accurate and reliable WROM measurements without direct physician contact. Passive WROM was more accurately measured from photographs than active WROM. This study builds on previous photography-based goniometry literature by validating a protocol in which patients or their families take and submit their own

Bayesian Nonparametric Regression Analysis of Data with Random Effects Covariates from Longitudinal Measurements

KAUST Repository

Ryu, Duchwan

2010-09-28

We consider nonparametric regression analysis in a generalized linear model (GLM) framework for data with covariates that are the subject-specific random effects of longitudinal measurements. The usual assumption that the effects of the longitudinal covariate processes are linear in the GLM may be unrealistic and if this happens it can cast doubt on the inference of observed covariate effects. Allowing the regression functions to be unknown, we propose to apply Bayesian nonparametric methods including cubic smoothing splines or P-splines for the possible nonlinearity and use an additive model in this complex setting. To improve computational efficiency, we propose the use of data-augmentation schemes. The approach allows flexible covariance structures for the random effects and within-subject measurement errors of the longitudinal processes. The posterior model space is explored through a Markov chain Monte Carlo (MCMC) sampler. The proposed methods are illustrated and compared to other approaches, the "naive" approach and the regression calibration, via simulations and by an application that investigates the relationship between obesity in adulthood and childhood growth curves. © 2010, The International Biometric Society.

A novel image encryption algorithm based on synchronized random bit generated in cascade-coupled chaotic semiconductor ring lasers

Science.gov (United States)

Li, Jiafu; Xiang, Shuiying; Wang, Haoning; Gong, Junkai; Wen, Aijun

2018-03-01

In this paper, a novel image encryption algorithm based on synchronization of physical random bit generated in a cascade-coupled semiconductor ring lasers (CCSRL) system is proposed, and the security analysis is performed. In both transmitter and receiver parts, the CCSRL system is a master-slave configuration consisting of a master semiconductor ring laser (M-SRL) with cross-feedback and a solitary SRL (S-SRL). The proposed image encryption algorithm includes image preprocessing based on conventional chaotic maps, pixel confusion based on control matrix extracted from physical random bit, and pixel diffusion based on random bit stream extracted from physical random bit. Firstly, the preprocessing method is used to eliminate the correlation between adjacent pixels. Secondly, physical random bit with verified randomness is generated based on chaos in the CCSRL system, and is used to simultaneously generate the control matrix and random bit stream. Finally, the control matrix and random bit stream are used for the encryption algorithm in order to change the position and the values of pixels, respectively. Simulation results and security analysis demonstrate that the proposed algorithm is effective and able to resist various typical attacks, and thus is an excellent candidate for secure image communication application.

New distributed fusion filtering algorithm based on covariances over sensor networks with random packet dropouts

Science.gov (United States)

Caballero-Águila, R.; Hermoso-Carazo, A.; Linares-Pérez, J.

2017-07-01

This paper studies the distributed fusion estimation problem from multisensor measured outputs perturbed by correlated noises and uncertainties modelled by random parameter matrices. Each sensor transmits its outputs to a local processor over a packet-erasure channel and, consequently, random losses may occur during transmission. Different white sequences of Bernoulli variables are introduced to model the transmission losses. For the estimation, each lost output is replaced by its estimator based on the information received previously, and only the covariances of the processes involved are used, without requiring the signal evolution model. First, a recursive algorithm for the local least-squares filters is derived by using an innovation approach. Then, the cross-correlation matrices between any two local filters is obtained. Finally, the distributed fusion filter weighted by matrices is obtained from the local filters by applying the least-squares criterion. The performance of the estimators and the influence of both sensor uncertainties and transmission losses on the estimation accuracy are analysed in a numerical example.

When to base clinical policies on observational versus randomized trial data.

Science.gov (United States)

Hornberger, J; Wrone, E

1997-10-15

Physicians must decide when the evidence is sufficient to adopt a new clinical policy. Analysis of large clinical and administrative databases is becoming an important source of evidence for changing clinical policies. Because such analysis cannot control for the effects of all potential confounding variables, physicians risk drawing the wrong conclusion about the cause-and-effect relation between a change in clinical policy and outcomes. Randomized studies offer protection against drawing a conclusion that would lead to adoption of an inferior policy. However, a randomized study may be difficult to justify because of the extra costs of collecting data for a randomized study and concerns that a study will not directly benefit the patients enrolled in the study. This article reviews the advantages and disadvantages of basing clinical policy on analysis of large databases compared with conducting a randomized study. A technique is described and illustrated for accessing the potential costs and benefits of conducting such a study. This type of analysis formed the basis for a physician-managed health care organization deciding to sponsor a randomized study among patients with end-stage renal disease as part of a quality-improvement initiative.

Measuring participant rurality in Web-based interventions

Directory of Open Access Journals (Sweden)

McKay H Garth

2007-08-01

Full Text Available Abstract Background Web-based health behavior change programs can reach large groups of disparate participants and thus they provide promise of becoming important public health tools. Data on participant rurality can complement other demographic measures to deepen our understanding of the success of these programs. Specifically, analysis of participant rurality can inform recruitment and social marketing efforts, and facilitate the targeting and tailoring of program content. Rurality analysis can also help evaluate the effectiveness of interventions across population groupings. Methods We describe how the RUCAs (Rural-Urban Commuting Area Codes methodology can be used to examine results from two Randomized Controlled Trials of Web-based tobacco cessation programs: the ChewFree.com project for smokeless tobacco cessation and the Smokers' Health Improvement Program (SHIP project for smoking cessation. Results Using RUCAs methodology helped to highlight the extent to which both Web-based interventions reached a substantial percentage of rural participants. The ChewFree program was found to have more rural participation which is consistent with the greater prevalence of smokeless tobacco use in rural settings as well as ChewFree's multifaceted recruitment program that specifically targeted rural settings. Conclusion Researchers of Web-based health behavior change programs targeted to the US should routinely include RUCAs as a part of analyzing participant demographics. Researchers in other countries should examine rurality indices germane to their country.

Robust state estimation for double pantographs with random missing measurements in high-speed railway

DEFF Research Database (Denmark)

Lu, Xiaobing; Liu, Zhigang; Wang, Yanbo

2016-01-01

Active control of pantograph could be performed to decrease the fluctuation in pantograph-catenary contact force (PCCF) in high-speed railway. However, it is difficult to obtain the states of the pantograph when state feedback control is implemented. And the measurements may randomly miss due...

Cross-covariance functions for multivariate random fields based on latent dimensions

KAUST Repository

Apanasovich, T. V.; Genton, M. G.

2010-01-01

The problem of constructing valid parametric cross-covariance functions is challenging. We propose a simple methodology, based on latent dimensions and existing covariance models for univariate random fields, to develop flexible, interpretable

Connectivity ranking of heterogeneous random conductivity models

Science.gov (United States)

Rizzo, C. B.; de Barros, F.

2017-12-01

To overcome the challenges associated with hydrogeological data scarcity, the hydraulic conductivity (K) field is often represented by a spatial random process. The state-of-the-art provides several methods to generate 2D or 3D random K-fields, such as the classic multi-Gaussian fields or non-Gaussian fields, training image-based fields and object-based fields. We provide a systematic comparison of these models based on their connectivity. We use the minimum hydraulic resistance as a connectivity measure, which it has been found to be strictly correlated with early time arrival of dissolved contaminants. A computationally efficient graph-based algorithm is employed, allowing a stochastic treatment of the minimum hydraulic resistance through a Monte-Carlo approach and therefore enabling the computation of its uncertainty. The results show the impact of geostatistical parameters on the connectivity for each group of random fields, being able to rank the fields according to their minimum hydraulic resistance.

Forecasting method in multilateration accuracy based on laser tracker measurement

International Nuclear Information System (INIS)

Aguado, Sergio; Santolaria, Jorge; Samper, David; José Aguilar, Juan

2017-01-01

Multilateration based on a laser tracker (LT) requires the measurement of a set of points from three or more positions. Although the LTs’ angular information is not used, multilateration produces a volume of measurement uncertainty. This paper presents two new coefficients from which to determine whether the measurement of a set of points, before performing the necessary measurements, will improve or worsen the accuracy of the multilateration results, avoiding unnecessary measurement, and reducing the time and economic cost required. The first specific coefficient measurement coefficient (MC LT ) is unique for each laser tracker. It determines the relationship between the radial and angular laser tracker measurement noise. Similarly, the second coefficient is related with specific conditions of measurement β . It is related with the spatial angle between the laser tracker positions α and its effect on error reduction. Both parameters MC LT and β are linked in error reduction limits. Beside these, a new methodology to determine the multilateration reduction limit according to the multilateration technique of an ideal laser tracker distribution and a random one are presented. It provides general rules and advice from synthetic tests that are validated through a real test carried out in a coordinate measurement machine. (paper)

School-based intervention to reduce anxiety in children: study protocol for a randomized controlled trial (PACES

Directory of Open Access Journals (Sweden)

Stallard Paul

2012-11-01

Full Text Available Abstract Background Emotional problems such as anxiety and low mood in children are common, impair everyday functioning and increase the risk of severe mental health disorders in adulthood. Relatively few children with emotional health problems are identified and referred for treatment indicating the need to investigate preventive approaches. Methods/Design The study is designed to be a pragmatic cluster randomized controlled trial evaluating the effectiveness of an efficacious school-based cognitive behavior therapy (CBT prevention program (FRIENDS on symptoms of anxiety and low mood in children 9 to 10 years of age. The unit of allocation is schools which are assigned to one of three conditions: school-led FRIENDS, health-led FRIENDS or treatment as usual. Assessments will be undertaken at baseline, 6 months and 12 months. The primary outcome measure is change on the Revised Child Anxiety and Depression Scale. Secondary outcome measures assess changes in self-esteem, worries, bullying and life satisfaction. An economic evaluation will be undertaken. Discussion As of September 2011, 41 schools have been recruited and randomized. Final 12-month assessments are scheduled to be completed by May 2013. Trial Registration ISRCTN23563048

Improving Pulse Rate Measurements during Random Motion Using a Wearable Multichannel Reflectance Photoplethysmograph

Directory of Open Access Journals (Sweden)

Kristen M. Warren

2016-03-01

Full Text Available Photoplethysmographic (PPG waveforms are used to acquire pulse rate (PR measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to motion artifacts (MA, limiting the implementation of PR measurements in mobile physiological monitoring devices. Previous studies have shown that multichannel photoplethysmograms can successfully acquire diverse signal information during simple, repetitive motion, leading to differences in motion tolerance across channels. In this paper, we investigate the performance of a custom-built multichannel forehead-mounted photoplethysmographic sensor under a variety of intense motion artifacts. We introduce an advanced multichannel template-matching algorithm that chooses the channel with the least motion artifact to calculate PR for each time instant. We show that for a wide variety of random motion, channels respond differently to motion artifacts, and the multichannel estimate outperforms single-channel estimates in terms of motion tolerance, signal quality, and PR errors. We have acquired 31 data sets consisting of PPG waveforms corrupted by random motion and show that the accuracy of PR measurements achieved was increased by up to 2.7 bpm when the multichannel-switching algorithm was compared to individual channels. The percentage of PR measurements with error ≤ 5 bpm during motion increased by 18.9% when the multichannel switching algorithm was compared to the mean PR from all channels. Moreover, our algorithm enables automatic selection of the best signal fidelity channel at each time point among the multichannel PPG data.

Task-Based Mirror Therapy Augmenting Motor Recovery in Poststroke Hemiparesis: A Randomized Controlled Trial.

Science.gov (United States)

Arya, Kamal Narayan; Pandian, Shanta; Kumar, Dharmendra; Puri, Vinod

2015-08-01

To establish the effect of the task-based mirror therapy (TBMT) on the upper limb recovery in stroke. A pilot, randomized, controlled, assessor-blinded trial was conducted in a rehabilitation institute. A convenience sample of 33 poststroke (mean duration, 12.5 months) hemiparetic subjects was randomized into 2 groups (experimental, 17; control, 16). The subjects were allocated to receive either TBMT or standard motor rehabilitation-40 sessions (5/week) for a period of 8 weeks. The TBMT group received movements using various goal-directed tasks and a mirror box. The movements were performed by the less-affected side superimposed on the affected side. The main outcome measures were Brunnstrom recovery stage (BRS) and Fugl-Meyer assessment (FMA)-FMA of upper extremity (FMA-UE), including upper arm (FMA-UA) and wrist-hand (FMA-WH). The TBMT group exhibited highly significant improvement on mean scores of FMA-WH (P hemiparesis. MT using tasks may be used as an adjunct in stroke rehabilitation. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Simultaneous spacecraft orbit estimation and control based on GPS measurements via extended Kalman filter

Directory of Open Access Journals (Sweden)

Tamer Mekky Ahmed Habib

2013-06-01

Full Text Available The primary aim of this work is to provide simultaneous spacecraft orbit estimation and control based on the global positioning system (GPS measurements suitable for application to the next coming Egyptian remote sensing satellites. Disturbance resulting from earth’s oblateness till the fourth order (i.e., J4 is considered. In addition, aerodynamic drag and random disturbance effects are taken into consideration.

93-106, 2015 93 Multilevel random effect and marginal models

African Journals Online (AJOL)

Multilevel random effect and marginal models for longitudinal data ... and random effect models that take the correlation among measurements of the same subject ... comparing the level of redness, pain and irritability ... clinical trial evaluating the safety profile of a new .... likelihood-based methods to compare models and.

Mindfulness-based cognitive therapy for multiple chemical sensitivity: a study protocol for a randomized controlled trial

Directory of Open Access Journals (Sweden)

Hauge Christian Riise

2012-09-01

Full Text Available Abstract Background Multiple chemical sensitivity (MCS is a condition characterized by recurrent, self-reported symptoms from multiple organ systems, attributable to exposure to a wide range of chemically unrelated substances at low levels. The pathophysiology is unknown, and affected individuals generally favor avoidance of the symptom triggering substances as a coping strategy. The impact of MCS on daily life may thus be severe. An intervention that may effectively reduce the impact of MCS, alleviate the symptoms and the psychological distress associated with the condition is therefore highly needed. In this study we will assess the effects of a mindfulness-based cognitive (MBCT program on MCS. Methods/Design Using a randomized controlled design (RCT, we will compare MBCT with treatment as usual (TAU. The MBCT intervention will include 8 weekly 2.5 hour sessions, and 45 minutes of mindfulness home practice 6 days each week. Participants will be asked to complete questionnaires at baseline, post-treatment, and at 6 and 12 months’ follow-up. Based on sample size estimation, 82 participants will be randomized to either the MBCT intervention or to TAU. The primary outcome will be a measure of the impact of MCS on the participants’ lives. The secondary outcome measures are physical symptoms of psychological distress, perceived stress, illness perceptions, QOL, and work ability. Lastly, we will assess whether any effect of MBCT on the primary effect measure is mediated by level of mindfulness, self-compassion, perceived stress, and rumination. Discussion This trial will provide important information on the effects of MBCT on MCS. Trials registration Clinical trials identifier NCT01240395

A Data Management System Integrating Web-based Training and Randomized Trials: Requirements, Experiences and Recommendations.

Science.gov (United States)

Muroff, Jordana; Amodeo, Maryann; Larson, Mary Jo; Carey, Margaret; Loftin, Ralph D

2011-01-01

This article describes a data management system (DMS) developed to support a large-scale randomized study of an innovative web-course that was designed to improve substance abuse counselors' knowledge and skills in applying a substance abuse treatment method (i.e., cognitive behavioral therapy; CBT). The randomized trial compared the performance of web-course-trained participants (intervention group) and printed-manual-trained participants (comparison group) to determine the effectiveness of the web-course in teaching CBT skills. A single DMS was needed to support all aspects of the study: web-course delivery and management, as well as randomized trial management. The authors briefly reviewed several other systems that were described as built either to handle randomized trials or to deliver and evaluate web-based training. However it was clear that these systems fell short of meeting our needs for simultaneous, coordinated management of the web-course and the randomized trial. New England Research Institute's (NERI) proprietary Advanced Data Entry and Protocol Tracking (ADEPT) system was coupled with the web-programmed course and customized for our purposes. This article highlights the requirements for a DMS that operates at the intersection of web-based course management systems and randomized clinical trial systems, and the extent to which the coupled, customized ADEPT satisfied those requirements. Recommendations are included for institutions and individuals considering conducting randomized trials and web-based training programs, and seeking a DMS that can meet similar requirements.

A school-based randomized controlled trial to improve physical activity among Iranian high school girls

Directory of Open Access Journals (Sweden)

Ghofranipour Fazloalha

2008-04-01

Full Text Available Abstract Background Physical activity (PA rates decline precipitously during the high school years and are consistently lower among adolescent girls than adolescent boys. Due to cultural barriers, this problem might be exacerbated in female Iranian adolescents. However, little intervention research has been conducted to try to increase PA participation rates with this population. Because PA interventions in schools have the potential to reach many children and adolescents, this study reports on PA intervention research conducted in all-female Iranian high schools. Methods A randomized controlled trial was conducted to examine the effects of two six-month tailored interventions on potential determinants of PA and PA behavior. Students (N = 161 were randomly allocated to one of three conditions: an intervention based on Pender's Health Promotion model (HP, an intervention based on an integration of the health promotion model and selected constructs from the Transtheoretical model (THP, and a control group (CON. Measures were administered prior to the intervention, at post-intervention and at a six-month follow-up. Results Repeated measure ANOVAs showed a significant interaction between group and time for perceived benefits, self efficacy, interpersonal norms, social support, behavioral processes, and PA behavior, indicating that both intervention groups significantly improved across the 24-week intervention, whereas the control group did not. Participants in the THP group showed greater use of counter conditioning and stimulus control at post-intervention and at follow-up. While there were no significant differences in PA between the HP and CON groups at follow-up, a significant difference was still found between the THP and the CON group. Conclusion This study provides the first evidence of the effectiveness of a PA intervention based on Pender's HP model combined with selected aspects of the TTM on potential determinants to increase PA among

The Optimal Wavelengths for Light Absorption Spectroscopy Measurements Based on Genetic Algorithm-Particle Swarm Optimization

Science.gov (United States)

Tang, Ge; Wei, Biao; Wu, Decao; Feng, Peng; Liu, Juan; Tang, Yuan; Xiong, Shuangfei; Zhang, Zheng

2018-03-01

To select the optimal wavelengths in the light extinction spectroscopy measurement, genetic algorithm-particle swarm optimization (GAPSO) based on genetic algorithm (GA) and particle swarm optimization (PSO) is adopted. The change of the optimal wavelength positions in different feature size parameters and distribution parameters is evaluated. Moreover, the Monte Carlo method based on random probability is used to identify the number of optimal wavelengths, and good inversion effects of the particle size distribution are obtained. The method proved to have the advantage of resisting noise. In order to verify the feasibility of the algorithm, spectra with bands ranging from 200 to 1000 nm are computed. Based on this, the measured data of standard particles are used to verify the algorithm.

A generalized complexity measure based on Rényi entropy

Science.gov (United States)

Sánchez-Moreno, Pablo; Angulo, Juan Carlos; Dehesa, Jesus S.

2014-08-01

The intrinsic statistical complexities of finite many-particle systems (i.e., those defined in terms of the single-particle density) quantify the degree of structure or patterns, far beyond the entropy measures. They are intuitively constructed to be minima at the opposite extremes of perfect order and maximal randomness. Starting from the pioneering LMC measure, which satisfies these requirements, some extensions of LMC-Rényi type have been published in the literature. The latter measures were shown to describe a variety of physical aspects of the internal disorder in atomic and molecular systems (e.g., quantum phase transitions, atomic shell filling) which are not grasped by their mother LMC quantity. However, they are not minimal for maximal randomness in general. In this communication, we propose a generalized LMC-Rényi complexity which overcomes this problem. Some applications which illustrate this fact are given.

Random Valued Impulse Noise Removal Using Region Based Detection Approach

Directory of Open Access Journals (Sweden)

S. Banerjee

2017-12-01

Full Text Available Removal of random valued noisy pixel is extremely challenging when the noise density is above 50%. The existing filters are generally not capable of eliminating such noise when density is above 70%. In this paper a region wise density based detection algorithm for random valued impulse noise has been proposed. On the basis of the intensity values, the pixels of a particular window are sorted and then stored into four regions. The higher density based region is considered for stepwise detection of noisy pixels. As a result of this detection scheme a maximum of 75% of noisy pixels can be detected. For this purpose this paper proposes a unique noise removal algorithm. It was experimentally proved that the proposed algorithm not only performs exceptionally when it comes to visual qualitative judgment of standard images but also this filter combination outsmarts the existing algorithm in terms of MSE, PSNR and SSIM comparison even up to 70% noise density level.

High-speed true random number generation based on paired memristors for security electronics

Science.gov (United States)

Zhang, Teng; Yin, Minghui; Xu, Changmin; Lu, Xiayan; Sun, Xinhao; Yang, Yuchao; Huang, Ru

2017-11-01

True random number generator (TRNG) is a critical component in hardware security that is increasingly important in the era of mobile computing and internet of things. Here we demonstrate a TRNG using intrinsic variation of memristors as a natural source of entropy that is otherwise undesirable in most applications. The random bits were produced by cyclically switching a pair of tantalum oxide based memristors and comparing their resistance values in the off state, taking advantage of the more pronounced resistance variation compared with that in the on state. Using an alternating read scheme in the designed TRNG circuit, the unbiasedness of the random numbers was significantly improved, and the bitstream passed standard randomness tests. The Pt/TaO x /Ta memristors fabricated in this work have fast programming/erasing speeds of ˜30 ns, suggesting a high random number throughput. The approach proposed here thus holds great promise for physically-implemented random number generation.

A 1-year videoconferencing-based psychoeducational group intervention following bariatric surgery: results of a randomized controlled study.

Science.gov (United States)

Wild, Beate; Hünnemeyer, Katharina; Sauer, Helene; Hain, Bernhard; Mack, Isabelle; Schellberg, Dieter; Müller-Stich, Beat Peter; Weiner, Rudolf; Meile, Tobias; Rudofsky, Gottfried; Königsrainer, Alfred; Zipfel, Stephan; Herzog, Wolfgang; Teufel, Martin

2015-01-01

For severely obese patients, bariatric surgery has been recommended as an effective therapy. The Bariataric Surgery and Education (BaSE) study aimed to assess the efficacy of a videoconferencing-based psychoeducational group intervention in patients after bariatric surgery. The BaSE study is a randomized, controlled multicenter clinical trial involving 117 patients undergoing bariatric surgery (mean preoperative body mass index [BMI] 49.9 kg/m(2), SD 6.4). Patients were enrolled between May 2009 and November 2012 and were randomly assigned to receive either conventional postsurgical visits or, in addition, a videoconferencing-based 1-year group program. Primary outcome measures were weight in kilograms, health-related quality of life (HRQOL), and general self-efficacy (GSE). Secondary outcome measures were depression symptoms and eating behavior. 94% of the patients completed the study. Mean weight loss for all patients was 45.9 kg (SD 16.4) 1 year after surgery (mean excess weight loss [EWL] 63%). Intention-to-treat analyses revealed no differences in weight loss, EWL, HRQOL, or self-efficacy between study groups at 1 year after surgery. However, patients with clinically significant depression symptoms (CSD) at baseline assigned to the intervention group (n = 29) had a significantly better HRQOL (P = .03), lower depression scores (P = .02), and a trend for a better EWL (.06) 1 year after surgery compared with the control group (n = 20). We could not prove the efficacy of the group program for the whole study sample. However, results indicate that the intervention is effective for the important subgroup of patients with CSD. Copyright © 2015 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Synthesis and characterization of sugar-based methacrylates and their random copolymers by ATRP

Directory of Open Access Journals (Sweden)

G. Acik

2017-10-01

Full Text Available Various sugar-based methacrylate monomers have been prepared and randomly copolymerized with methyl methacrylate (MMA using classical atom transfer radical polymerization (ATRP. Firstly, four different sugar-based methacrylates are synthesized by two-step method: (i etherification of protected monosaccharides with epichlorohydrin and (ii following ring-opening reaction of obtained epoxides with methacrylic acid (MAA in the presence of triethylamine. Next, these monomers are copolymerized with MMA via ATRP at 90 °C to obtain corresponding random copolymers. The molecular weights of the copolymers are determined by both GPC (gel permeation chromatography and 1H-NMR (nuclear magnetic resonance spectroscopy analyses and found as 10600~16800 and 12200~18500 g/mol, respectively. Moreover, the copolymer compositions are also determined by 1H-NMR analysis using characteristic signals of the monomers and found as about 94.1~97.8%, which are good agreement with feeding ratio. In addition, the glass transition temperatures of copolymers are found as 101.2~102.9 °C by changing type and composition of sugar-based methacrylate monomers. Overall, a series of well-defined random copolymers comprising different sugar-based methacrylates and methyl methacrylates were successfully synthesized by classical ATRP method.

A Community-Based Randomized Trial of Hepatitis B Screening Among High-Risk Vietnamese Americans.

Science.gov (United States)

Ma, Grace X; Fang, Carolyn Y; Seals, Brenda; Feng, Ziding; Tan, Yin; Siu, Philip; Yeh, Ming Chin; Golub, Sarit A; Nguyen, Minhhuyen T; Tran, Tam; Wang, Minqi

2017-03-01

To evaluate the effectiveness of a community-based liver cancer prevention program on hepatitis B virus (HBV) screening among low-income, underserved Vietnamese Americans at high risk. We conducted a cluster randomized trial involving 36 Vietnamese community-based organizations and 2337 participants in Pennsylvania, New Jersey, and New York City between 2009 and 2014. We randomly assigned 18 community-based organizations to a community-based multilevel HBV screening intervention (n = 1131). We randomly assigned the remaining 18 community-based organizations to a general cancer education program (n = 1206), which included information about HBV-related liver cancer prevention. We assessed HBV screening rates at 6-month follow-up. Intervention participants were significantly more likely to have undergone HBV screening (88.1%) than were control group participants (4.6%). In a Cochran-Mantel-Haenszel analysis, the intervention effect on screening outcomes remained statistically significant after adjustment for demographic and health care access variables, including income, having health insurance, having a regular health provider, and English proficiency. A community-based, culturally appropriate, multilevel HBV screening intervention effectively increases screening rates in a high-risk, hard-to-reach Vietnamese American population.

A data based random number generator for a multivariate distribution (using stochastic interpolation)

Science.gov (United States)

Thompson, J. R.; Taylor, M. S.

1982-01-01

Let X be a K-dimensional random variable serving as input for a system with output Y (not necessarily of dimension k). given X, an outcome Y or a distribution of outcomes G(Y/X) may be obtained either explicitly or implicity. The situation is considered in which there is a real world data set X sub j sub = 1 (n) and a means of simulating an outcome Y. A method for empirical random number generation based on the sample of observations of the random variable X without estimating the underlying density is discussed.

Fiber-Type Random Laser Based on a Cylindrical Waveguide with a Disordered Cladding Layer.

Science.gov (United States)

Zhang, Wei Li; Zheng, Meng Ya; Ma, Rui; Gong, Chao Yang; Yang, Zhao Ji; Peng, Gang Ding; Rao, Yun Jiang

2016-05-25

This letter reports a fiber-type random laser (RL) which is made from a capillary coated with a disordered layer at its internal surface and filled with a gain (laser dye) solution in the core region. This fiber-type optical structure, with the disordered layer providing randomly scattered light into the gain region and the cylindrical waveguide providing confinement of light, assists the formation of random lasing modes and enables a flexible and efficient way of making random lasers. We found that the RL is sensitive to laser dye concentration in the core region and there exists a fine exponential relationship between the lasing intensity and particle concentration in the gain solution. The proposed structure could be a fine platform of realizing random lasing and random lasing based sensing.

ANALYTIC WORD RECOGNITION WITHOUT SEGMENTATION BASED ON MARKOV RANDOM FIELDS

NARCIS (Netherlands)

Coisy, C.; Belaid, A.

2004-01-01

In this paper, a method for analytic handwritten word recognition based on causal Markov random fields is described. The words models are HMMs where each state corresponds to a letter; each letter is modelled by a NSHP­HMM (Markov field). Global models are build dynamically, and used for recognition

Random Measurement Error as a Source of Discrepancies between the Reports of Wives and Husbands Concerning Marital Power and Task Allocation.

Science.gov (United States)

Quarm, Daisy

1981-01-01

Findings for couples (N=119) show wife's work, money, and spare time low between-spouse correlations are due in part to random measurement error. Suggests that increasing reliability of measures by creating multi-item indices can also increase correlations. Car purchase, vacation, and child discipline were not accounted for by random measurement…

Enhancing Security of Double Random Phase Encoding Based on Random S-Box

Science.gov (United States)

Girija, R.; Singh, Hukum

2018-06-01

In this paper, we propose a novel asymmetric cryptosystem for double random phase encoding (DRPE) using random S-Box. While utilising S-Box separately is not reliable and DRPE does not support non-linearity, so, our system unites the effectiveness of S-Box with an asymmetric system of DRPE (through Fourier transform). The uniqueness of proposed cryptosystem lies on employing high sensitivity dynamic S-Box for our DRPE system. The randomness and scalability achieved due to applied technique is an additional feature of the proposed solution. The firmness of random S-Box is investigated in terms of performance parameters such as non-linearity, strict avalanche criterion, bit independence criterion, linear and differential approximation probabilities etc. S-Boxes convey nonlinearity to cryptosystems which is a significant parameter and very essential for DRPE. The strength of proposed cryptosystem has been analysed using various parameters such as MSE, PSNR, correlation coefficient analysis, noise analysis, SVD analysis, etc. Experimental results are conferred in detail to exhibit proposed cryptosystem is highly secure.

A randomized, controlled clinical trial: the effect of mindfulness-based cognitive therapy on generalized anxiety disorder among Chinese community patients: protocol for a randomized trial

Directory of Open Access Journals (Sweden)

Wong Samuel YS

2011-11-01

Full Text Available Abstract Background Research suggests that an eight-week Mindfulness-Based Cognitive Therapy (MBCT program may be effective in the treatment of generalized anxiety disorders. Our objective is to compare the clinical effectiveness of the MBCT program with a psycho-education programme and usual care in reducing anxiety symptoms in people suffering from generalized anxiety disorder. Methods A three armed randomized, controlled clinical trial including 9-month post-treatment follow-up is proposed. Participants screened positive using the Structure Clinical Interview for DSM-IV (SCID for general anxiety disorder will be recruited from community-based clinics. 228 participants will be randomly allocated to the MBCT program plus usual care, psycho-education program plus usual care or the usual care group. Validated Chinese version of instruments measuring anxiety and worry symptoms, depression, quality of life and health service utilization will be used. Our primary end point is the change of anxiety and worry score (Beck Anxiety Inventory and Penn State Worry Scale from baseline to the end of intervention. For primary analyses, treatment outcomes will be assessed by ANCOVA, with change in anxiety score as the baseline variable, while the baseline anxiety score and other baseline characteristics that significantly differ between groups will serve as covariates. Conclusions This is a first randomized controlled trial that compare the effectiveness of MBCT with an active control, findings will advance current knowledge in the management of GAD and the way that group intervention can be delivered and inform future research. Unique Trail Number (assigned by Centre for Clinical Trails, Clinical Trials registry, The Chinese University of Hong Kong: CUHK_CCT00267

Shape measurement system for single point incremental forming (SPIF) manufacts by using trinocular vision and random pattern

International Nuclear Information System (INIS)

Setti, Francesco; Bini, Ruggero; Lunardelli, Massimo; Bosetti, Paolo; Bruschi, Stefania; De Cecco, Mariolino

2012-01-01

Many contemporary works show the interest of the scientific community in measuring the shape of artefacts made by single point incremental forming. In this paper, we will present an algorithm able to detect feature points with a random pattern, check the compatibility of associations exploiting multi-stereo constraints and reject outliers and perform a 3D reconstruction by dense random patterns. The algorithm is suitable for a real-time application, in fact it needs just three images and a synchronous relatively fast processing. The proposed method has been tested on a simple geometry and results have been compared with a coordinate measurement machine acquisition. (paper)

Random a-adic groups and random net fractals

Energy Technology Data Exchange (ETDEWEB)

Li Yin [Department of Mathematics, Nanjing University, Nanjing 210093 (China)], E-mail: Lyjerry7788@hotmail.com; Su Weiyi [Department of Mathematics, Nanjing University, Nanjing 210093 (China)], E-mail: suqiu@nju.edu.cn

2008-08-15

Based on random a-adic groups, this paper investigates the relationship between the existence conditions of a positive flow in a random network and the estimation of the Hausdorff dimension of a proper random net fractal. Subsequently we describe some particular random fractals for which our results can be applied. Finally the Mauldin and Williams theorem is shown to be very important example for a random Cantor set with application in physics as shown in E-infinity theory.

An internet-based intervention for adjustment disorder (TAO): study protocol for a randomized controlled trial.

Science.gov (United States)

Rachyla, Iryna; Pérez-Ara, Marian; Molés, Mar; Campos, Daniel; Mira, Adriana; Botella, Cristina; Quero, Soledad

2018-05-31

Adjustment Disorder (AjD) is a common and disabling mental health problem. The lack of research on this disorder has led to the absence of evidence-based interventions for its treatment. Moreover, because the available data indicate that a high percentage of people with mental illness are not treated, it is necessary to develop new ways to provide psychological assistance. The present study describes a Randomized Controlled Trial (RCT) aimed at assessing the effectiveness and acceptance of a linear internet-delivered cognitive-behavioral therapy (ICBT) intervention for AjD. A two-armed RCT was designed to compare an intervention group to a waiting list control group. Participants from the intervention group will receive TAO, an internet-based program for AjD composed of seven modules. TAO combines CBT and Positive Psychology strategies in order to provide patients with complete support, reducing their clinical symptoms and enhancing their capacity to overcome everyday adversity. Participants will also receive short weekly telephone support. Participants in the control group will be assessed before and after a seven-week waiting period, and then they will be offered the same intervention. Participants will be randomly assigned to one of the 2 groups. Measurements will be taken at five different moments: baseline, post-intervention, and three follow-up periods (3-, 6- and 12-month). BDI-II and BAI will be used as primary outcome measures. Secondary outcomes will be symptoms of AjD, posttraumatic growth, positive and negative affect, and quality of life. The development of ICBT programs like TAO responds to a need for evidence-based interventions that can reach most of the people who need them, reducing the burden and cost of mental disorders. More specifically, TAO targets AjD and will entail a step forward in the treatment of this prevalent but under-researched disorder. Finally, it should be noted that this is the first RCT focusing on an internet-based

Research on machine learning framework based on random forest algorithm

Science.gov (United States)

Ren, Qiong; Cheng, Hui; Han, Hai

2017-03-01

With the continuous development of machine learning, industry and academia have released a lot of machine learning frameworks based on distributed computing platform, and have been widely used. However, the existing framework of machine learning is limited by the limitations of machine learning algorithm itself, such as the choice of parameters and the interference of noises, the high using threshold and so on. This paper introduces the research background of machine learning framework, and combined with the commonly used random forest algorithm in machine learning classification algorithm, puts forward the research objectives and content, proposes an improved adaptive random forest algorithm (referred to as ARF), and on the basis of ARF, designs and implements the machine learning framework.

Web-Based Education Prior to Outpatient Orthopaedic Surgery Enhances Early Patient Satisfaction Scores: A Prospective Randomized Controlled Study.

Science.gov (United States)

van Eck, Carola F; Toor, Aneet; Banffy, Michael B; Gambardella, Ralph A

2018-01-01

A good patient-surgeon relationship relies on adequate preoperative education and counseling. Several multimedia resources, such as web-based education tools, have become available to enhance aspects of perioperative care. The purpose of this study was to evaluate the effect of an interactive web-based education tool on perioperative patient satisfaction scores after outpatient orthopaedic surgery. It was hypothesized that web-based education prior to outpatient orthopaedic surgery enhances patient satisfaction scores. Randomized controlled trial; Level of evidence, 1. All patients undergoing knee arthroscopy with meniscectomy, chondroplasty, or anterior cruciate ligament reconstruction or shoulder arthroscopy with rotator cuff repair were eligible for inclusion and were randomized to the study or control group. The control group received routine education by the surgeon, whereas the study group received additional web-based education. At the first postoperative visit, all patients completed the OAS CAHPS (Outpatient and Ambulatory Surgery Consumer Assessment of Healthcare Providers and Systems) survey. Differences in patient satisfaction scores between the study and control groups were determined with an independent t test. A total of 177 patients were included (104 [59%] males; mean age, 42 ± 14 years); 87 (49%) patients were randomized to receive additional web-based education. Total patient satisfaction score was significantly higher in the study group (97 ± 5) as compared with the control group (94 ± 8; P = .019), specifically for the OAS CAHPS core measure "recovery" (92 ± 13 vs 82 ± 23; P = .001). Age, sex, race, workers' compensation status, education level, overall health, emotional health, procedure type and complexity, and addition of a video did not influence patient satisfaction scores. Supplemental web-based patient education prior to outpatient orthopaedic surgery enhances patient satisfaction scores.

The Hidden Flow Structure and Metric Space of Network Embedding Algorithms Based on Random Walks.

Science.gov (United States)

Gu, Weiwei; Gong, Li; Lou, Xiaodan; Zhang, Jiang

2017-10-13

Network embedding which encodes all vertices in a network as a set of numerical vectors in accordance with it's local and global structures, has drawn widespread attention. Network embedding not only learns significant features of a network, such as the clustering and linking prediction but also learns the latent vector representation of the nodes which provides theoretical support for a variety of applications, such as visualization, link prediction, node classification, and recommendation. As the latest progress of the research, several algorithms based on random walks have been devised. Although those algorithms have drawn much attention for their high scores in learning efficiency and accuracy, there is still a lack of theoretical explanation, and the transparency of those algorithms has been doubted. Here, we propose an approach based on the open-flow network model to reveal the underlying flow structure and its hidden metric space of different random walk strategies on networks. We show that the essence of embedding based on random walks is the latent metric structure defined on the open-flow network. This not only deepens our understanding of random- walk-based embedding algorithms but also helps in finding new potential applications in network embedding.

Internet-Based, Randomized Controlled Trial of Omega-3 Fatty Acids for Hyperactivity in Autism

Science.gov (United States)

Bent, Stephen; Hendren, Robert L.; Zandi, Tara; Law, Kiely; Choi, Jae-Eun; Widjaja, Felicia; Kalb, Luther; Nestle, Jay; Law, Paul

2014-01-01

Objective Preliminary evidence suggests that omega-3 fatty acids may reduce hyperactivity in children with autism spectrum disorder (ASD). We sought to examine the feasibility of a novel, internet-based clinical trial design to evaluate the efficacy of this supplement. Method E-mail invitations were sent to parents of children aged 5-8 enrolled in the Interactive Autism Network. All study procedures, including screening, informed consent, and collection of outcome measures took place over the internet. The primary outcome measures were parent- and teacher-rated changes in hyperactivity on the Aberrant Behavior Checklist. Results During the 6-week recruitment period, 57 children from 28 states satisfied all eligibility criteria and were randomly assigned to 1.3 grams of omega-3 fatty acids or an identical placebo daily for 6 weeks. Outcome assessments were obtained from all 57 participants and 57 teachers, and the study was completed in 3 months. Children in the omega-3 fatty acid group had a greater reduction in hyperactivity (-5.3 points) compared to the placebo group (-2.6 points), but the difference was not statistically significant (1.9 point greater improvement in the omega-3 group, 95% CI -2.2 to 5.2). Side effects were rare and not associated with omega-3 fatty acids. Participant feedback was positive. Conclusion Internet-based randomized controlled trials of therapies in children with ASD are feasible and may lead to marked reductions in the time and cost of completing trials. A larger sample size is required to definitively determine the efficacy of omega-3 fatty acids. Clinical trial registration information—Omega-3 Fatty Acids for Hyperactivity Treatment in Autism Spectrum Disorder; http://clinicaltrials.gov; NCT01694667. PMID:24839884

Web-Based Cognitive Remediation Improves Supported Employment Outcomes in Severe Mental Illness: Randomized Controlled Trial.

Science.gov (United States)

Harris, Anthony Wf; Kosic, Tanya; Xu, Jean; Walker, Chris; Gye, William; Redoblado Hodge, Antoinette

2017-09-20

Finding work is a top priority for most people; however, this goal remains out of reach for the majority of individuals with a severe mental illness (SMI) who remain on benefits or are unemployed. Supported employment (SE) programs aimed at returning people with a severe mental illness to work are successful; however, they still leave a significant number of people with severe mental illness unemployed. Cognitive deficits are commonly found in SMI and are a powerful predictor of poor outcome. Fortunately, these deficits are amenable to treatment with cognitive remediation therapy (CRT) that significantly improves cognition in SMI. CRT combined with SE significantly increases the likelihood of individuals with severe mental illness obtaining and staying in work. However, the availability of CRT is limited in many settings. The aim of this study was to examine whether Web-based CRT combined with a SE program can improve the rate return to work of people with severe mental illness. A total of 86 people with severe mental illness (mean age 39.6 years; male: n=55) who were unemployed and who had joined a SE program were randomized to either a Web-based CRT program (CogRem) or an Internet-based control condition (WebInfo). Primary outcome measured was hours worked over 6 months post treatment. At 6 months, those participants randomized to CogRem had worked significantly more hours (P=.01) and had earned significantly more money (P=.03) than those participants randomized to the WebInfo control condition. No change was observed in cognition. This study corroborates other work that has found a synergistic effect of combining CRT with a SE program and extends this to the use of Web-based CRT. The lack of any improvement in cognition obscures the mechanism by which an improved wage outcome for participants randomized to the active treatment was achieved. However, the study substantially lowers the barrier to the deployment of CRT with other psychosocial interventions for

Validation of a photography-based goniometry method for measuring joint range of motion.

Science.gov (United States)

Blonna, Davide; Zarkadas, Peter C; Fitzsimmons, James S; O'Driscoll, Shawn W

2012-01-01

A critical component of evaluating the outcomes after surgery to restore lost elbow motion is the range of motion (ROM) of the elbow. This study examined if digital photography-based goniometry is as accurate and reliable as clinical goniometry for measuring elbow ROM. Instrument validity and reliability for photography-based goniometry were evaluated for a consecutive series of 50 elbow contractures by 4 observers with different levels of elbow experience. Goniometric ROM measurements were taken with the elbows in full extension and full flexion directly in the clinic (once) and from digital photographs (twice in a blinded random manner). Instrument validity for photography-based goniometry was extremely high (intraclass correlation coefficient: extension = 0.98, flexion = 0.96). For extension and flexion measurements by the expert surgeon, systematic error was negligible (0° and 1°, respectively). Limits of agreement were 7° (95% confidence interval [CI], 5° to 9°) and -7° (95% CI, -5° to -9°) for extension and 8° (95% CI, 6° to 10°) and -7° (95% CI, -5° to -9°) for flexion. Interobserver reliability for photography-based goniometry was better than that for clinical goniometry. The least experienced observer's photographic goniometry measurements were closer to the reference measurements than the clinical goniometry measurements. Photography-based goniometry is accurate and reliable for measuring elbow ROM. The photography-based method relied less on observer expertise than clinical goniometry. This validates an objective measure of patient outcome without requiring doctor-patient contact at a tertiary care center, where most contracture surgeries are done. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Ellipsometry with randomly varying polarization states

NARCIS (Netherlands)

Liu, F.; Lee, C. J.; Chen, J. Q.; E. Louis,; van der Slot, P. J. M.; Boller, K. J.; F. Bijkerk,

2012-01-01

We show that, under the right conditions, one can make highly accurate polarization-based measurements without knowing the absolute polarization state of the probing light field. It is shown that light, passed through a randomly varying birefringent material has a well-defined orbit on the Poincar

Exposure and non-fear emotions: A randomized controlled study of exposure-based and rescripting-based imagery in PTSD treatment.

Science.gov (United States)

Langkaas, Tomas Formo; Hoffart, Asle; Øktedalen, Tuva; Ulvenes, Pål G; Hembree, Elizabeth A; Smucker, Mervin

2017-10-01

Interventions involving rescripting-based imagery have been proposed as a better approach than exposure-based imagery when posttraumatic stress disorder (PTSD) is associated with emotions other than fear. Prior research led to the study's hypotheses that (a) higher pretreatment non-fear emotions would predict relatively better response to rescripting as compared to exposure, (b) rescripting would be associated with greater reduction in non-fear emotions, and (c) pretreatment non-fear emotions would predict poor response to exposure. A clinically representative sample of 65 patients presenting a wide range of traumas was recruited from patients seeking and being offered PTSD treatment in an inpatient setting. Subjects were randomly assigned to 10 weeks of treatment involving either rescripting-based imagery (Imagery Rescripting; IR) or exposure-based imagery (Prolonged Exposure; PE). Patients were assessed on outcome and emotion measures at pretreatment, posttreatment and 12 months follow-up. Comparison to control benchmarks indicated that both treatments were effective, but no outcome differences between them appeared. None of the initial hypotheses were supported. The results from this study challenge previous observations and hypotheses about exposure mainly being effective for fear-based PTSD and strengthen the notion that exposure-based treatment is a generally effective treatment for all types of PTSD. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Copula Based Approach for Design of Multivariate Random Forests for Drug Sensitivity Prediction.

Science.gov (United States)

Haider, Saad; Rahman, Raziur; Ghosh, Souparno; Pal, Ranadip

2015-01-01

Modeling sensitivity to drugs based on genetic characterizations is a significant challenge in the area of systems medicine. Ensemble based approaches such as Random Forests have been shown to perform well in both individual sensitivity prediction studies and team science based prediction challenges. However, Random Forests generate a deterministic predictive model for each drug based on the genetic characterization of the cell lines and ignores the relationship between different drug sensitivities during model generation. This application motivates the need for generation of multivariate ensemble learning techniques that can increase prediction accuracy and improve variable importance ranking by incorporating the relationships between different output responses. In this article, we propose a novel cost criterion that captures the dissimilarity in the output response structure between the training data and node samples as the difference in the two empirical copulas. We illustrate that copulas are suitable for capturing the multivariate structure of output responses independent of the marginal distributions and the copula based multivariate random forest framework can provide higher accuracy prediction and improved variable selection. The proposed framework has been validated on genomics of drug sensitivity for cancer and cancer cell line encyclopedia database.

Controlling Chronic Diseases Through Evidence-Based Decision Making: A Group-Randomized Trial.

Science.gov (United States)

Brownson, Ross C; Allen, Peg; Jacob, Rebekah R; deRuyter, Anna; Lakshman, Meenakshi; Reis, Rodrigo S; Yan, Yan

2017-11-30

Although practitioners in state health departments are ideally positioned to implement evidence-based interventions, few studies have examined how to build their capacity to do so. The objective of this study was to explore how to increase the use of evidence-based decision-making processes at both the individual and organization levels. We conducted a 2-arm, group-randomized trial with baseline data collection and follow-up at 18 to 24 months. Twelve state health departments were paired and randomly assigned to intervention or control condition. In the 6 intervention states, a multiday training on evidence-based decision making was conducted from March 2014 through March 2015 along with a set of supplemental capacity-building activities. Individual-level outcomes were evidence-based decision making skills of public health practitioners; organization-level outcomes were access to research evidence and participatory decision making. Mixed analysis of covariance models was used to evaluate the intervention effect by accounting for the cluster randomized trial design. Analysis was performed from March through May 2017. Participation 18 to 24 months after initial training was 73.5%. In mixed models adjusted for participant and state characteristics, the intervention group improved significantly in the overall skill gap (P = .01) and in 6 skill areas. Among the 4 organizational variables, only access to evidence and skilled staff showed an intervention effect (P = .04). Tailored and active strategies are needed to build capacity at the individual and organization levels for evidence-based decision making. Our study suggests several dissemination interventions for consideration by leaders seeking to improve public health practice.

A programmable Gaussian random pulse generator for automated performance measurements

International Nuclear Information System (INIS)

Abdel-Aal, R.E.

1989-01-01

This paper describes a versatile random signal generator which produces logic pulses with a Gaussian distribution for the pulse spacing. The average rate at the pulse generator output can be software-programmed, which makes it useful in performing automated measurements of dead time and CPU time performance of data acquisition systems and modules over a wide range of data rates. Hardware and software components are described and data on the input-output characteristics and the statistical properties of the pulse generator are given. Typical applications are discussed together with advantages over using radioactive test sources. Results obtained from an automated performance run on a VAX 11/785 data acquisition system are presented. (orig.)

Quantum random bit generation using energy fluctuations in stimulated Raman scattering.

Science.gov (United States)

Bustard, Philip J; England, Duncan G; Nunn, Josh; Moffatt, Doug; Spanner, Michael; Lausten, Rune; Sussman, Benjamin J

2013-12-02

Random number sequences are a critical resource in modern information processing systems, with applications in cryptography, numerical simulation, and data sampling. We introduce a quantum random number generator based on the measurement of pulse energy quantum fluctuations in Stokes light generated by spontaneously-initiated stimulated Raman scattering. Bright Stokes pulse energy fluctuations up to five times the mean energy are measured with fast photodiodes and converted to unbiased random binary strings. Since the pulse energy is a continuous variable, multiple bits can be extracted from a single measurement. Our approach can be generalized to a wide range of Raman active materials; here we demonstrate a prototype using the optical phonon line in bulk diamond.

Joint Conditional Random Field Filter for Multi-Object Tracking

Directory of Open Access Journals (Sweden)

Luo Ronghua

2011-03-01

Full Text Available Object tracking can improve the performance of mobile robot especially in populated dynamic environments. A novel joint conditional random field Filter (JCRFF based on conditional random field with hierarchical structure is proposed for multi-object tracking by abstracting the data associations between objects and measurements to be a sequence of labels. Since the conditional random field makes no assumptions about the dependency structure between the observations and it allows non-local dependencies between the state and the observations, the proposed method can not only fuse multiple cues including shape information and motion information to improve the stability of tracking, but also integrate moving object detection and object tracking quite well. At the same time, implementation of multi-object tracking based on JCRFF with measurements from the laser range finder on a mobile robot is studied. Experimental results with the mobile robot developed in our lab show that the proposed method has higher precision and better stability than joint probabilities data association filter (JPDAF.

Measuring Clinical Decision Support Influence on Evidence-Based Nursing Practice.

Science.gov (United States)

Cortez, Susan; Dietrich, Mary S; Wells, Nancy

2016-07-01

To measure the effect of clinical decision support (CDS) on oncology nurse evidence-based practice (EBP).
. Longitudinal cluster-randomized design.
. Four distinctly separate oncology clinics associated with an academic medical center.
. The study sample was comprised of randomly selected data elements from the nursing documentation software. The data elements were patient-reported symptoms and the associated nurse interventions. The total sample observations were 600, derived from a baseline, posteducation, and postintervention sample of 200 each (100 in the intervention group and 100 in the control group for each sample).
. The cluster design was used to support randomization of the study intervention at the clinic level rather than the individual participant level to reduce possible diffusion of the study intervention. An elongated data collection cycle (11 weeks) controlled for temporary increases in nurse EBP related to the education or CDS intervention.
. The dependent variable was the nurse evidence-based documentation rate, calculated from the nurse-documented interventions. The independent variable was the CDS added to the nursing documentation software.
. The average EBP rate at baseline for the control and intervention groups was 27%. After education, the average EBP rate increased to 37%, and then decreased to 26% in the postintervention sample. Mixed-model linear statistical analysis revealed no significant interaction of group by sample. The CDS intervention did not result in an increase in nurse EBP.
. EBP education increased nurse EBP documentation rates significantly but only temporarily. Nurses may have used evidence in practice but may not have documented their interventions.
. More research is needed to understand the complex relationship between CDS, nursing practice, and nursing EBP intervention documentation. CDS may have a different effect on nurse EBP, physician EBP, and other medical professional EBP.

Sign Compute Resolve for Random Access

DEFF Research Database (Denmark)

Goseling, Jasper; Stefanovic, Cedomir; Popovski, Petar

2014-01-01

users collide. We measure the performance of the proposed method in terms of user resolution rate as well as overall throughput of the system. The results show that our approach significantly increases the performance of the system even compared to coded random access, where collisions are not wasted......We present an approach to random access that is based on three elements: physical-layer network coding, signature codes and tree splitting. Upon occurrence of a collision, physical-layer network coding enables the receiver to decode the sum of the information that was transmitted by the individual...

Testing the efficacy of web-based cognitive behavioural therapy for adult patients with chronic fatigue syndrome (CBIT): study protocol for a randomized controlled trial.

Science.gov (United States)

Janse, Anthonie; Worm-Smeitink, Margreet; Bussel-Lagarde, José; Bleijenberg, Gijs; Nikolaus, Stephanie; Knoop, Hans

2015-08-12

Cognitive behavioural therapy (CBT) is an effective treatment for fatigue and disabilities in patients with chronic fatigue syndrome (CFS). However, treatment capacity is limited. Providing web-based CBT and tailoring the amount of contact with the therapist to the individual needs of the patient may increase the efficiency of the intervention. Web-based CBT for adolescents with CFS has proven to be effective in reducing fatigue and increasing school attendance. In the proposed study the efficacy of a web-based CBT intervention for adult patients with CFS will be explored. Two different formats of web-based CBT will be tested. In the first format named protocol driven feedback, patients report on their progress and receive feedback from a therapist according to a preset schedule. In the second format named support on demand, feedback and support of the therapist is only given when patients ask for it. The primary objective of the study is to determine the efficacy of a web-based CBT intervention on fatigue severity. A randomized clinical trial will be conducted. Two-hundred-forty adults who have been diagnosed with CFS according to the US Centers for Disease Control and Prevention (CDC) consensus criteria will be recruited and randomized to one of three conditions: web-based CBT with protocol driven feedback, web-based CBT with support on demand, or wait list. Feedback will be delivered by therapists specialized in CBT for CFS. Each of the web-based CBT interventions will be compared to a wait list condition with respect to its effect on the primary outcome measure; fatigue severity. Secondary outcome measures are level of disability, physical functioning, psychological distress, and the proportion of patients with clinical significant improvement in fatigue severity. Outcomes will be assessed at baseline and six months post randomization. The web-based CBT formats will be compared with respect to the time therapists need to deliver the intervention. As far as we

Using ecological momentary assessment to test the effectiveness of a web-based brief alcohol intervention over time among heavy-drinking students: randomized controlled trial.

Science.gov (United States)

Voogt, Carmen; Kuntsche, Emmanuel; Kleinjan, Marloes; Poelen, Evelien; Engels, Rutger

2014-01-08

Web-based brief alcohol interventions are effective in reducing alcohol use among students when measured at limited follow-up time points. To date, no studies have tested Web-based brief alcohol intervention effectiveness over time by using a large number of measurements. Testing whether the What Do You Drink (WDYD) Web-based brief alcohol intervention can sustain a reduction in alcohol use among heavy-drinking students aged 18-24 years at 1-, 3-, and 6-month follow-up intervals. A purely Web-based, 2-arm, parallel-group randomized controlled trial applying an ecological momentary assessment approach with 30 weekly measurements was conducted in the Netherlands (2010-2011). Participants were recruited offline and online. A total of 907 participants were randomized into the experimental condition (n=456) including the single-session and fully automated WDYD intervention, or into the control condition (n=451) including assessment only. Weekly alcohol consumption and frequency of binge drinking were the self-assessed outcome measures. Attrition rates of the 907 participants were 110 (12.1%), 130 (14.3%), and 162 (17.9%) at 1-, 3-, and 6-month follow-up intervals, respectively. Latent growth curve analyses according to the intention-to-treat principle revealed that participants in the experimental condition had significantly lower weekly alcohol consumption compared to participants in the control condition that was sustained at 3-month follow-up (intercept=-2.60, Padmin/rctview.asp?TC=2665 (Archived by WebCite at http://webcitation.org/6LuQVn12M).

Bluetooth-based distributed measurement system

International Nuclear Information System (INIS)

Tang Baoping; Chen Zhuo; Wei Yuguo; Qin Xiaofeng

2007-01-01

A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit

Bluetooth-based distributed measurement system

Science.gov (United States)

Tang, Baoping; Chen, Zhuo; Wei, Yuguo; Qin, Xiaofeng

2007-07-01

A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit.

Bluetooth-based distributed measurement system

Energy Technology Data Exchange (ETDEWEB)

Tang Baoping; Chen Zhuo; Wei Yuguo; Qin Xiaofeng [Department of Mechatronics, College of Mechanical Engineering, Chongqing University, Chongqing, 400030 (China)

2007-07-15

A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit.

Random walk centrality for temporal networks

International Nuclear Information System (INIS)

Rocha, Luis E C; Masuda, Naoki

2014-01-01

Nodes can be ranked according to their relative importance within a network. Ranking algorithms based on random walks are particularly useful because they connect topological and diffusive properties of the network. Previous methods based on random walks, for example the PageRank, have focused on static structures. However, several realistic networks are indeed dynamic, meaning that their structure changes in time. In this paper, we propose a centrality measure for temporal networks based on random walks under periodic boundary conditions that we call TempoRank. It is known that, in static networks, the stationary density of the random walk is proportional to the degree or the strength of a node. In contrast, we find that, in temporal networks, the stationary density is proportional to the in-strength of the so-called effective network, a weighted and directed network explicitly constructed from the original sequence of transition matrices. The stationary density also depends on the sojourn probability q, which regulates the tendency of the walker to stay in the node, and on the temporal resolution of the data. We apply our method to human interaction networks and show that although it is important for a node to be connected to another node with many random walkers (one of the principles of the PageRank) at the right moment, this effect is negligible in practice when the time order of link activation is included. (paper)

Random walk centrality for temporal networks

Science.gov (United States)

Rocha, Luis E. C.; Masuda, Naoki

2014-06-01

Nodes can be ranked according to their relative importance within a network. Ranking algorithms based on random walks are particularly useful because they connect topological and diffusive properties of the network. Previous methods based on random walks, for example the PageRank, have focused on static structures. However, several realistic networks are indeed dynamic, meaning that their structure changes in time. In this paper, we propose a centrality measure for temporal networks based on random walks under periodic boundary conditions that we call TempoRank. It is known that, in static networks, the stationary density of the random walk is proportional to the degree or the strength of a node. In contrast, we find that, in temporal networks, the stationary density is proportional to the in-strength of the so-called effective network, a weighted and directed network explicitly constructed from the original sequence of transition matrices. The stationary density also depends on the sojourn probability q, which regulates the tendency of the walker to stay in the node, and on the temporal resolution of the data. We apply our method to human interaction networks and show that although it is important for a node to be connected to another node with many random walkers (one of the principles of the PageRank) at the right moment, this effect is negligible in practice when the time order of link activation is included.

Random fiber laser based on artificially controlled backscattering fibers.

Science.gov (United States)

Wang, Xiaoliang; Chen, Daru; Li, Haitao; She, Lijuan; Wu, Qiong

2018-01-10

The random fiber laser (RFL), which is a milestone in laser physics and nonlinear optics, has attracted considerable attention recently. Most previously reported RFLs are based on distributed feedback of Rayleigh scattering amplified through the stimulated Raman-Brillouin scattering effect in single-mode fibers, which require long-distance (tens of kilometers) single-mode fibers and high threshold, up to watt level, due to the extremely small Rayleigh scattering coefficient of the fiber. We proposed and demonstrated a half-open-cavity RFL based on a segment of an artificially controlled backscattering single-mode fiber with a length of 210 m, 310 m, or 390 m. A fiber Bragg grating with a central wavelength of 1530 nm and a segment of artificially controlled backscattering single-mode fiber fabricated by using a femtosecond laser form the half-open cavity. The proposed RFL achieves thresholds of 25 mW, 30 mW, and 30 mW, respectively. Random lasing at a wavelength of 1530 nm and extinction ratio of 50 dB is achieved when a segment of 5 m erbium-doped fiber is pumped by a 980 nm laser diode in the RFL. A novel RFL with many short cavities has been achieved with low threshold.

A randomized controlled trial of a community-based nutrition education program for low-income parents.

Science.gov (United States)

Dollahite, Jamie S; Pijai, Erika I; Scott-Pierce, Michelle; Parker, Carol; Trochim, William

2014-01-01

Assess effectiveness of the Expanded Food and Nutrition Education Program on nutrition behaviors post-education and longitudinally. Switching replications randomized experimental design. Participants randomly assigned to immediate education (IE) or delayed education (DE). Participants in IE received intervention the first 8 weeks, and those in DE the second 8 weeks, with no intervention during alternate periods. Data were collected in 3 repeated measures. Parents (n = 168 randomized; n = 134 completed) of children in 2 Head Start and 6 low-income schools. Eight weekly workshops, based on Eating Right is Basic-Enhanced adapted to incorporate dialogue approach with experiential learning. Ten-item self-reported behavior checklist on nutrition, food resource management, food safety, and food security; responses on a 5-point scale reporting frequency of behavior. Chi-square, analysis of variance, and multiple regression. Groups were demographically similar. Both groups reported improved behaviors pre- to post-education (P vs T2). Changed IE behavior was retained T2 to T3. A multiple regression model of overall change, controlling for T1 score and educator, showed significant improvement (n = 134, β = 5.72, P < .001). Positive outcomes were supported by this experimental study in a usual program context, with reported behavior changes retained at least 2 months. Copyright © 2014 Society for Nutrition Education and Behavior. All rights reserved.

Multiple ECG Fiducial Points-Based Random Binary Sequence Generation for Securing Wireless Body Area Networks.

Science.gov (United States)

Zheng, Guanglou; Fang, Gengfa; Shankaran, Rajan; Orgun, Mehmet A; Zhou, Jie; Qiao, Li; Saleem, Kashif

2017-05-01

Generating random binary sequences (BSes) is a fundamental requirement in cryptography. A BS is a sequence of N bits, and each bit has a value of 0 or 1. For securing sensors within wireless body area networks (WBANs), electrocardiogram (ECG)-based BS generation methods have been widely investigated in which interpulse intervals (IPIs) from each heartbeat cycle are processed to produce BSes. Using these IPI-based methods to generate a 128-bit BS in real time normally takes around half a minute. In order to improve the time efficiency of such methods, this paper presents an ECG multiple fiducial-points based binary sequence generation (MFBSG) algorithm. The technique of discrete wavelet transforms is employed to detect arrival time of these fiducial points, such as P, Q, R, S, and T peaks. Time intervals between them, including RR, RQ, RS, RP, and RT intervals, are then calculated based on this arrival time, and are used as ECG features to generate random BSes with low latency. According to our analysis on real ECG data, these ECG feature values exhibit the property of randomness and, thus, can be utilized to generate random BSes. Compared with the schemes that solely rely on IPIs to generate BSes, this MFBSG algorithm uses five feature values from one heart beat cycle, and can be up to five times faster than the solely IPI-based methods. So, it achieves a design goal of low latency. According to our analysis, the complexity of the algorithm is comparable to that of fast Fourier transforms. These randomly generated ECG BSes can be used as security keys for encryption or authentication in a WBAN system.

Pigmented skin lesion detection using random forest and wavelet-based texture

Science.gov (United States)

Hu, Ping; Yang, Tie-jun

2016-10-01

The incidence of cutaneous malignant melanoma, a disease of worldwide distribution and is the deadliest form of skin cancer, has been rapidly increasing over the last few decades. Because advanced cutaneous melanoma is still incurable, early detection is an important step toward a reduction in mortality. Dermoscopy photographs are commonly used in melanoma diagnosis and can capture detailed features of a lesion. A great variability exists in the visual appearance of pigmented skin lesions. Therefore, in order to minimize the diagnostic errors that result from the difficulty and subjectivity of visual interpretation, an automatic detection approach is required. The objectives of this paper were to propose a hybrid method using random forest and Gabor wavelet transformation to accurately differentiate which part belong to lesion area and the other is not in a dermoscopy photographs and analyze segmentation accuracy. A random forest classifier consisting of a set of decision trees was used for classification. Gabor wavelets transformation are the mathematical model of visual cortical cells of mammalian brain and an image can be decomposed into multiple scales and multiple orientations by using it. The Gabor function has been recognized as a very useful tool in texture analysis, due to its optimal localization properties in both spatial and frequency domain. Texture features based on Gabor wavelets transformation are found by the Gabor filtered image. Experiment results indicate the following: (1) the proposed algorithm based on random forest outperformed the-state-of-the-art in pigmented skin lesions detection (2) and the inclusion of Gabor wavelet transformation based texture features improved segmentation accuracy significantly.

A Randomized Controlled Trial of Mindfulness Meditation for Chronic Insomnia

Science.gov (United States)

Ong, Jason C.; Manber, Rachel; Segal, Zindel; Xia, Yinglin; Shapiro, Shauna; Wyatt, James K.

2014-01-01

Study Objectives: To evaluate the efficacy of mindfulness meditation for the treatment of chronic insomnia. Design: Three-arm, single-site, randomized controlled trial. Setting: Academic medical center. Participants: Fifty-four adults with chronic insomnia. Interventions: Participants were randomized to either mindfulness-based stress reduction (MBSR), mindfulness-based therapy for insomnia (MBTI), or an eight-week self-monitoring (SM) condition. Measurements and Results: Patient-reported outcome measures were total wake time (TWT) from sleep diaries, the pre-sleep arousal scale (PSAS), measuring a prominent waking correlate of insomnia, and the Insomnia Severity Index (ISI) to determine remission and response as clinical endpoints. Objective sleep measures were derived from laboratory polysomnography and wrist actigraphy. Linear mixed models showed that those receiving a meditation-based intervention (MBSR or MBTI) had significantly greater reductions on TWT minutes (43.75 vs 1.09), PSAS (7.13 vs 0.16), and ISI (4.56 vs 0.06) from baseline-to-post compared to SM. Post hoc analyses revealed that each intervention was superior to SM on each of the patient-reported measures, but no significant differences were found when comparing MBSR to MBTI from baseline-to-post. From baseline to 6-month follow-up, MBTI had greater reductions in ISI scores than MBSR (P insomnia and could provide an alternative to traditional treatments for insomnia. Trial Registration: Mindfulness-Based Approaches to Insomnia: clinicaltrials.gov, identifier: NCT00768781 Citation: Ong JC, Manber R, Segal Z, Xia Y, Shapiro S, Wyatt JK. A randomized controlled trial of mindfulness meditation for chronic insomnia. SLEEP 2014;37(9):1553-1563. PMID:25142566

QUASI-RANDOM TESTING OF COMPUTER SYSTEMS

Directory of Open Access Journals (Sweden)

S. V. Yarmolik

2013-01-01

Full Text Available Various modified random testing approaches have been proposed for computer system testing in the black box environment. Their effectiveness has been evaluated on the typical failure patterns by employing three measures, namely, P-measure, E-measure and F-measure. A quasi-random testing, being a modified version of the random testing, has been proposed and analyzed. The quasi-random Sobol sequences and modified Sobol sequences are used as the test patterns. Some new methods for Sobol sequence generation have been proposed and analyzed.

Experimental study of a quantum random-number generator based on two independent lasers

Science.gov (United States)

Sun, Shi-Hai; Xu, Feihu

2017-12-01

A quantum random-number generator (QRNG) can produce true randomness by utilizing the inherent probabilistic nature of quantum mechanics. Recently, the spontaneous-emission quantum phase noise of the laser has been widely deployed for quantum random-number generation, due to its high rate, its low cost, and the feasibility of chip-scale integration. Here, we perform a comprehensive experimental study of a phase-noise-based QRNG with two independent lasers, each of which operates in either continuous-wave (CW) or pulsed mode. We implement the QRNG by operating the two lasers in three configurations, namely, CW + CW, CW + pulsed, and pulsed + pulsed, and demonstrate their trade-offs, strengths, and weaknesses.

Robust portfolio selection based on asymmetric measures of variability of stock returns

Science.gov (United States)

Chen, Wei; Tan, Shaohua

2009-10-01

This paper addresses a new uncertainty set--interval random uncertainty set for robust optimization. The form of interval random uncertainty set makes it suitable for capturing the downside and upside deviations of real-world data. These deviation measures capture distributional asymmetry and lead to better optimization results. We also apply our interval random chance-constrained programming to robust mean-variance portfolio selection under interval random uncertainty sets in the elements of mean vector and covariance matrix. Numerical experiments with real market data indicate that our approach results in better portfolio performance.

Particle filters for random set models

CERN Document Server

Ristic, Branko

2013-01-01

“Particle Filters for Random Set Models” presents coverage of state estimation of stochastic dynamic systems from noisy measurements, specifically sequential Bayesian estimation and nonlinear or stochastic filtering. The class of solutions presented in this book is based  on the Monte Carlo statistical method. The resulting  algorithms, known as particle filters, in the last decade have become one of the essential tools for stochastic filtering, with applications ranging from  navigation and autonomous vehicles to bio-informatics and finance. While particle filters have been around for more than a decade, the recent theoretical developments of sequential Bayesian estimation in the framework of random set theory have provided new opportunities which are not widely known and are covered in this book. These recent developments have dramatically widened the scope of applications, from single to multiple appearing/disappearing objects, from precise to imprecise measurements and measurement models. This book...

Experimentally generated randomness certified by the impossibility of superluminal signals.

Science.gov (United States)

Bierhorst, Peter; Knill, Emanuel; Glancy, Scott; Zhang, Yanbao; Mink, Alan; Jordan, Stephen; Rommal, Andrea; Liu, Yi-Kai; Christensen, Bradley; Nam, Sae Woo; Stevens, Martin J; Shalm, Lynden K

2018-04-01

From dice to modern electronic circuits, there have been many attempts to build better devices to generate random numbers. Randomness is fundamental to security and cryptographic systems and to safeguarding privacy. A key challenge with random-number generators is that it is hard to ensure that their outputs are unpredictable 1-3 . For a random-number generator based on a physical process, such as a noisy classical system or an elementary quantum measurement, a detailed model that describes the underlying physics is necessary to assert unpredictability. Imperfections in the model compromise the integrity of the device. However, it is possible to exploit the phenomenon of quantum non-locality with a loophole-free Bell test to build a random-number generator that can produce output that is unpredictable to any adversary that is limited only by general physical principles, such as special relativity 1-11 . With recent technological developments, it is now possible to carry out such a loophole-free Bell test 12-14,22 . Here we present certified randomness obtained from a photonic Bell experiment and extract 1,024 random bits that are uniformly distributed to within 10 -12 . These random bits could not have been predicted according to any physical theory that prohibits faster-than-light (superluminal) signalling and that allows independent measurement choices. To certify and quantify the randomness, we describe a protocol that is optimized for devices that are characterized by a low per-trial violation of Bell inequalities. Future random-number generators based on loophole-free Bell tests may have a role in increasing the security and trust of our cryptographic systems and infrastructure.

Fault Diagnosis for Hydraulic Servo System Using Compressed Random Subspace Based ReliefF

Directory of Open Access Journals (Sweden)

Yu Ding

2018-01-01

Full Text Available Playing an important role in electromechanical systems, hydraulic servo system is crucial to mechanical systems like engineering machinery, metallurgical machinery, ships, and other equipment. Fault diagnosis based on monitoring and sensory signals plays an important role in avoiding catastrophic accidents and enormous economic losses. This study presents a fault diagnosis scheme for hydraulic servo system using compressed random subspace based ReliefF (CRSR method. From the point of view of feature selection, the scheme utilizes CRSR method to determine the most stable feature combination that contains the most adequate information simultaneously. Based on the feature selection structure of ReliefF, CRSR employs feature integration rules in the compressed domain. Meanwhile, CRSR substitutes information entropy and fuzzy membership for traditional distance measurement index. The proposed CRSR method is able to enhance the robustness of the feature information against interference while selecting the feature combination with balanced information expressing ability. To demonstrate the effectiveness of the proposed CRSR method, a hydraulic servo system joint simulation model is constructed by HyPneu and Simulink, and three fault modes are injected to generate the validation data.

Can group-based reassuring information alter low back pain behavior? A cluster-randomized controlled trial

DEFF Research Database (Denmark)

Frederiksen, Pernille; Indahl, Aage; Andersen, Lars L

2017-01-01

-randomized controlled trial. METHODS: Publically employed workers (n = 505) from 11 Danish municipality centers were randomized at center-level (cluster) to either intervention (two 1-hour group-based talks at the workplace) or control. The talks provided reassuring information together with a simple non...

Covariance-Based Measurement Selection Criterion for Gaussian-Based Algorithms

Directory of Open Access Journals (Sweden)

Fernando A. Auat Cheein

2013-01-01

Full Text Available Process modeling by means of Gaussian-based algorithms often suffers from redundant information which usually increases the estimation computational complexity without significantly improving the estimation performance. In this article, a non-arbitrary measurement selection criterion for Gaussian-based algorithms is proposed. The measurement selection criterion is based on the determination of the most significant measurement from both an estimation convergence perspective and the covariance matrix associated with the measurement. The selection criterion is independent from the nature of the measured variable. This criterion is used in conjunction with three Gaussian-based algorithms: the EIF (Extended Information Filter, the EKF (Extended Kalman Filter and the UKF (Unscented Kalman Filter. Nevertheless, the measurement selection criterion shown herein can also be applied to other Gaussian-based algorithms. Although this work is focused on environment modeling, the results shown herein can be applied to other Gaussian-based algorithm implementations. Mathematical descriptions and implementation results that validate the proposal are also included in this work.

Inference-Based Similarity Search in Randomized Montgomery Domains for Privacy-Preserving Biometric Identification.

Science.gov (United States)

Wang, Yi; Wan, Jianwu; Guo, Jun; Cheung, Yiu-Ming; C Yuen, Pong

2017-07-14

Similarity search is essential to many important applications and often involves searching at scale on high-dimensional data based on their similarity to a query. In biometric applications, recent vulnerability studies have shown that adversarial machine learning can compromise biometric recognition systems by exploiting the biometric similarity information. Existing methods for biometric privacy protection are in general based on pairwise matching of secured biometric templates and have inherent limitations in search efficiency and scalability. In this paper, we propose an inference-based framework for privacy-preserving similarity search in Hamming space. Our approach builds on an obfuscated distance measure that can conceal Hamming distance in a dynamic interval. Such a mechanism enables us to systematically design statistically reliable methods for retrieving most likely candidates without knowing the exact distance values. We further propose to apply Montgomery multiplication for generating search indexes that can withstand adversarial similarity analysis, and show that information leakage in randomized Montgomery domains can be made negligibly small. Our experiments on public biometric datasets demonstrate that the inference-based approach can achieve a search accuracy close to the best performance possible with secure computation methods, but the associated cost is reduced by orders of magnitude compared to cryptographic primitives.

Water-based vs. non-water-based physiotherapy for rehabilitation of postural deformities in Parkinson's disease: a randomized controlled pilot study.

Science.gov (United States)

Volpe, Daniele; Giantin, Maria Giulia; Manuela, Pilleri; Filippetto, Consuelo; Pelosin, Elisa; Abbruzzese, Giovanni; Antonini, Angelo

2017-08-01

To compare the efficacy of two physiotherapy protocols (water-based vs. non-water-based) on postural deformities of patients with Parkinson's disease. A single blind, randomized controlled pilot study. Inpatient (Rehabilitative Department). A total of 30 patients with idiopathic Parkinson's disease. Participants were randomly assigned to one of two eight-week treatment groups: Water-based ( n = 15) or non-water-based physiotherapy exercises ( n = 15). Changes in the degree of cervical and dorsal flexion and in the angle of lateral inclination of the trunk (evaluated by means of a posturographic system) were used as primary outcomes. Unified Parkinson Disease Rating Scale section III, Time Up and Go Test, Berg Balance Scale, Activities-specific Balance Confidence, Falls Efficacy Scale and the Parkinson's disease quality of life questionnaire (39 items) were the secondary outcomes. All outcomes were assessed at baseline, at the end of training and eight weeks after treatment. Patients were always tested at the time of their optimal antiparkinsonian medication ('on' phase). After the treatment, only Parkinson's disease subjects randomized to water-based treatment showed a significant improvement of trunk posture with a significant reduction of cervical flexion (water-based group: -65.2°; non-water-based group: +1.7°) and dorsal flexion (water-based group: -22.5°; non-water-based group: -6.5°) and lateral inclination of the trunk (water-based group: -2.3°; non-water-based group: +0.3°). Both groups presented significant improvements in the secondary clinical outcomes without between-group differences. Our results show that water-based physiotherapy was effective for improving postural deformities in patients with Parkinson's disease.

Concentration inequalities for functions of Gibbs fields with application to diffraction and random Gibbs measures

CERN Document Server

Külske, C

2003-01-01

We derive useful general concentration inequalities for functions of Gibbs fields in the uniqueness regime. We also consider expectations of random Gibbs measures that depend on an additional disorder field, and prove concentration w.r.t the disorder field. Both fields are assumed to be in the uniqueness regime, allowing in particular for non-independent disorder field. The modification of the bounds compared to the case of an independent field can be expressed in terms of constants that resemble the Dobrushin contraction coefficient, and are explicitly computable. On the basis of these inequalities, we obtain bounds on the deviation of a diffraction pattern created by random scatterers located on a general discrete point set in the Euclidean space, restricted to a finite volume. Here we also allow for thermal dislocations of the scatterers around their equilibrium positions. Extending recent results for independent scatterers, we give a universal upper bound on the probability of a deviation of the random sc...

Measurements of Electromagnetic Fields Emitted from Cellular Base Stations in

Directory of Open Access Journals (Sweden)

K. J. Ali

2013-05-01

Full Text Available With increasing the usage of mobile communication devices and internet network information, the entry of private telecommunications companies in Iraq has been started since 2003. These companies began to build up cellular towers to accomplish the telecommunication works but they ignore the safety conditions imposed for the health and environment that are considered in random way. These negative health effects which may cause a health risk for life beings and environment pollution. The aim of this work is to determine the safe and unsafe ranges and discuss damage caused by radiation emitted from Asia cell base stations in Shirqat city and discuses the best ways in which can be minimize its exposure level to avoid its negative health effects. Practical measurements of power density around base stations has been accomplished by using a radiation survey meter type (Radio frequency EMF Strength Meter 480846 in two ways. The first way of measurements has been accomplished at a height of 2 meters above ground for different distances from (0-300 meters .The second way is at a distance of 150 meters for different levels from (2-15 meters above ground level. The maximum measured power density is about (3 mW/m2. Results indicate that the levels of power density are far below the RF radiation exposure of USSR safety standards levels. And that means these cellular base station don't cause negative the health effect for life being if the exposure is within the acceptable international standard levels.

Elimination of drift in a fiber-Bragg-grating-based multiplexed Michelson interferometer measurement system.

Science.gov (United States)

Ren, Junyu; Xie, Fang; Chen, Zhimin

2010-02-01

Random phase drift in single-mode optical fiber interferometers used with measurement systems, which is resulted from various types of environmental disturbances, should be eliminated in order to obtain high measurement precision. We propose an optical fiber interferometric measurement system which has the function of self-eliminating the random phase drift and is stable and robust enough for real-time precision measurement. By employing the characteristics of fiber Bragg gratings, the system interleaves two fiber Michelson interferometers together that share the common-interferometric-optical path. The signal of one of the interferometers is used to stabilize the system while the signal of the other interferometer is used for measurement. An electronic feedback loop for the stabilizing action is designed. The bandwidth of the feedback loop is 5 kHz, sufficiently wide to eliminate random phase drift resulted from various environmental disturbances. The system is endowed with high stability and therefore suitable for real-time precision measurement. By means of an active phase tracking technique to measure displacement, the linear regression coefficient of the displacement measurement results is 0.9998.

Improving the spectral measurement accuracy based on temperature distribution and spectra-temperature relationship

Science.gov (United States)

Li, Zhe; Feng, Jinchao; Liu, Pengyu; Sun, Zhonghua; Li, Gang; Jia, Kebin

2018-05-01

Temperature is usually considered as a fluctuation in near-infrared spectral measurement. Chemometric methods were extensively studied to correct the effect of temperature variations. However, temperature can be considered as a constructive parameter that provides detailed chemical information when systematically changed during the measurement. Our group has researched the relationship between temperature-induced spectral variation (TSVC) and normalized squared temperature. In this study, we focused on the influence of temperature distribution in calibration set. Multi-temperature calibration set selection (MTCS) method was proposed to improve the prediction accuracy by considering the temperature distribution of calibration samples. Furthermore, double-temperature calibration set selection (DTCS) method was proposed based on MTCS method and the relationship between TSVC and normalized squared temperature. We compare the prediction performance of PLS models based on random sampling method and proposed methods. The results from experimental studies showed that the prediction performance was improved by using proposed methods. Therefore, MTCS method and DTCS method will be the alternative methods to improve prediction accuracy in near-infrared spectral measurement.

Errors due to random noise in velocity measurement using incoherent-scatter radar

Directory of Open Access Journals (Sweden)

P. J. S. Williams

1996-12-01

Full Text Available The random-noise errors involved in measuring the Doppler shift of an 'incoherent-scatter' spectrum are predicted theoretically for all values of Te/Ti from 1.0 to 3.0. After correction has been made for the effects of convolution during transmission and reception and the additional errors introduced by subtracting the average of the background gates, the rms errors can be expressed by a simple semi-empirical formula. The observed errors are determined from a comparison of simultaneous EISCAT measurements using an identical pulse code on several adjacent frequencies. The plot of observed versus predicted error has a slope of 0.991 and a correlation coefficient of 99.3%. The prediction also agrees well with the mean of the error distribution reported by the standard EISCAT analysis programme.

Random number generation based on digital differential chaos

KAUST Repository

Zidan, Mohammed A.

2012-07-29

In this paper, we present a fully digital differential chaos based random number generator. The output of the digital circuit is proved to be chaotic by calculating the output time series maximum Lyapunov exponent. We introduce a new post processing technique to improve the distribution and statistical properties of the generated data. The post-processed output passes the NIST Sp. 800-22 statistical tests. The system is written in Verilog VHDL and realized on Xilinx Virtex® FPGA. The generator can fit into a very small area and have a maximum throughput of 2.1 Gb/s.

Time of flight measurements based on FPGA using a breast dedicated PET

International Nuclear Information System (INIS)

Aguilar, A; García-Olcina, R; Martos, J; Soret, J; Torres, J; Benlloch, J M; González, A J; Sánchez, F

2014-01-01

In this work the implementation of a Time-to-Digital Converter (TDC) using a Nutt delay line FPGA-based and applied on a Positron Emission Tomography (PET) device is going to be presented in order to check the system's suitability for Time of Flight (TOF) measurements. In recent years, FPGAs have shown great advantages for precise time measurements in PET. The architecture employed for these measurements is described in detail. The system developed was tested on a dedicated breast PET prototype, composed of LYSO crystals and Positive Sensitive Photomultipliers (PSPMTs). Two distinct experiments were carried out for this purpose. In the first test, system linearity was evaluated in order to calibrate the time measurements, providing a linearity error of less than 2% and an average time resolution of 1.4 ns FWHM. The second set of measurements tested system resolution, resulting in a FWHM as good as 1.35 ns. The results suggest that the coincidence window for the current PET can be reduced in order to minimize the random events and thus, achieve better image quality

Prediction of Geological Subsurfaces Based on Gaussian Random Field Models

Energy Technology Data Exchange (ETDEWEB)

Abrahamsen, Petter

1997-12-31

During the sixties, random functions became practical tools for predicting ore reserves with associated precision measures in the mining industry. This was the start of the geostatistical methods called kriging. These methods are used, for example, in petroleum exploration. This thesis reviews the possibilities for using Gaussian random functions in modelling of geological subsurfaces. It develops methods for including many sources of information and observations for precise prediction of the depth of geological subsurfaces. The simple properties of Gaussian distributions make it possible to calculate optimal predictors in the mean square sense. This is done in a discussion of kriging predictors. These predictors are then extended to deal with several subsurfaces simultaneously. It is shown how additional velocity observations can be used to improve predictions. The use of gradient data and even higher order derivatives are also considered and gradient data are used in an example. 130 refs., 44 figs., 12 tabs.

Web-Based Cognitive Behavioral Therapy for Female Patients With Eating Disorders: Randomized Controlled Trial.

Science.gov (United States)

ter Huurne, Elke D; de Haan, Hein A; Postel, Marloes G; van der Palen, Job; VanDerNagel, Joanne E L; DeJong, Cornelis A J

2015-06-18

Many patients with eating disorders do not receive help for their symptoms, even though these disorders have severe morbidity. The Internet may offer alternative low-threshold treatment interventions. This study evaluated the effects of a Web-based cognitive behavioral therapy (CBT) intervention using intensive asynchronous therapeutic support to improve eating disorder psychopathology, and to reduce body dissatisfaction and related health problems among patients with eating disorders. A two-arm open randomized controlled trial comparing a Web-based CBT intervention to a waiting list control condition (WL) was carried out among female patients with bulimia nervosa (BN), binge eating disorder (BED), and eating disorders not otherwise specified (EDNOS). The eating disorder diagnosis was in accordance with the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and was established based on participants' self-report. Participants were recruited from an open-access website, and the intervention consisted of a structured two-part program within a secure Web-based application. The aim of the first part was to analyze participant's eating attitudes and behaviors, while the second part focused on behavioral change. Participants had asynchronous contact with a personal therapist twice a week, solely via the Internet. Self-report measures of eating disorder psychopathology (primary outcome), body dissatisfaction, physical health, mental health, self-esteem, quality of life, and social functioning were completed at baseline and posttest. A total of 214 participants were randomized to either the Web-based CBT group (n=108) or to the WL group (n=106) stratified by type of eating disorder (BN: n=44; BED: n=85; EDNOS: n=85). Study attrition was low with 94% of the participants completing the posttest assignment. Overall, Web-based CBT showed a significant improvement over time for eating disorder psychopathology (F97=63.07, PWeb-based CBT participants in all three

Validation of Web-Based Physical Activity Measurement Systems Using Doubly Labeled Water

Science.gov (United States)

Yamaguchi, Yukio; Yamada, Yosuke; Tokushima, Satoru; Hatamoto, Yoichi; Sagayama, Hiroyuki; Kimura, Misaka; Higaki, Yasuki; Tanaka, Hiroaki

2012-01-01

Background Online or Web-based measurement systems have been proposed as convenient methods for collecting physical activity data. We developed two Web-based physical activity systems—the 24-hour Physical Activity Record Web (24hPAR WEB) and 7 days Recall Web (7daysRecall WEB). Objective To examine the validity of two Web-based physical activity measurement systems using the doubly labeled water (DLW) method. Methods We assessed the validity of the 24hPAR WEB and 7daysRecall WEB in 20 individuals, aged 25 to 61 years. The order of email distribution and subsequent completion of the two Web-based measurements systems was randomized. Each measurement tool was used for a week. The participants’ activity energy expenditure (AEE) and total energy expenditure (TEE) were assessed over each week using the DLW method and compared with the respective energy expenditures estimated using the Web-based systems. Results The mean AEE was 3.90 (SD 1.43) MJ estimated using the 24hPAR WEB and 3.67 (SD 1.48) MJ measured by the DLW method. The Pearson correlation for AEE between the two methods was r = .679 (P WEB and 3.80 (SD 1.36) MJ by the DLW method. The Pearson correlation for AEE between the two methods was r = .144 (P = .54). The Bland-Altman 95% limits of agreement ranged from –3.83 to 4.81 MJ between the two methods. The Pearson correlation for TEE between the two methods was r = .590 (P = .006). The average input times using terminal devices were 8 minutes and 10 seconds for the 24hPAR WEB and 6 minutes and 38 seconds for the 7daysRecall WEB. Conclusions Both Web-based systems were found to be effective methods for collecting physical activity data and are appropriate for use in epidemiological studies. Because the measurement accuracy of the 24hPAR WEB was moderate to high, it could be suitable for evaluating the effect of interventions on individuals as well as for examining physical activity behavior. PMID:23010345

A Rewritable, Random-Access DNA-Based Storage System.

Science.gov (United States)

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.

Non-Markovianity Measure Based on Brukner-Zeilinger Invariant Information for Unital Quantum Dynamical Maps

Science.gov (United States)

He, Zhi; Zhu, Lie-Qiang; Li, Li

2017-03-01

A non-Markovianity measure based on Brukner-Zeilinger invariant information to characterize non-Markovian effect of open systems undergoing unital dynamical maps is proposed. The method takes advantage of non-increasing property of the Brukner-Zeilinger invariant information under completely positive and trace-preserving unital maps. The simplicity of computing the Brukner-Zeilinger invariant information is the advantage of the proposed measure because of mainly depending on the purity of quantum state. The measure effectively captures the characteristics of non-Markovianity of unital dynamical maps. As some concrete application, we consider two typical non-Markovian noise channels, i.e., the phase damping channel and the random unitary channel to show the sensitivity of the proposed measure. By investigation, we find that the conditions of detecting the non-Markovianity for the phase damping channel are consistent with the results of existing measures for non-Markovianity, i.e., information flow, divisibility and quantum mutual information. However, for the random unitary channel non-Markovian conditions are same to that of the information flow, but is different from that of the divisibility and quantum mutual information. Supported by the National Natural Science Foundation of China under Grant No. 61505053, the Natural Science Foundation of Hunan Province under Grant No. 2015JJ3092, the Research Foundation of Education Bureau of Hunan Province, China under Grant No. 16B177, the School Foundation from the Hunan University of Arts and Science under Grant No. 14ZD01

Internet-based cognitive behavior therapy for major depressive disorder: A randomized controlled trial.

Science.gov (United States)

Rosso, Isabelle M; Killgore, William D S; Olson, Elizabeth A; Webb, Christian A; Fukunaga, Rena; Auerbach, Randy P; Gogel, Hannah; Buchholz, Jennifer L; Rauch, Scott L

2017-03-01

Prior research has shown that the Sadness Program, a technician-assisted Internet-based cognitive behavioral therapy (iCBT) intervention developed in Australia, is effective for treating major depressive disorder (MDD). The current study aimed to expand this work by adapting the protocol for an American population and testing the Sadness Program with an attention control group. In this parallel-group, randomized controlled trial, adult MDD participants (18-45 years) were randomized to a 10-week period of iCBT (n = 37) or monitored attention control (MAC; n = 40). Participants in the iCBT group completed six online therapy lessons, which included access to content summaries and homework assignments. During the 10-week trial, iCBT and MAC participants logged into the web-based system six times to complete self-report symptom scales, and a nonclinician technician contacted participants weekly to provide encouragement and support. The primary outcome was the Hamilton Rating Scale for Depression (HRSD), and the secondary outcomes were the Patient Health Questionnaire-9 and Kessler-10. Intent-to-treat analyses revealed significantly greater reductions in depressive symptoms in iCBT compared with MAC participants, using both the self-report measures and the clinician-rated HRSD (d = -0.80). Importantly, iCBT participants also showed significantly higher rates of clinical response and remission. Exploratory analyses did not support illness severity as a moderator of treatment outcome. The Sadness Program led to significant reductions in depression and distress symptoms. With its potential to be delivered in a scalable, cost-efficient manner, iCBT is a promising strategy to enhance access to effective care. © 2016 Wiley Periodicals, Inc.

Evaluation of domain randomness in periodically poled lithium niobate by diffraction noise measurement.

Science.gov (United States)

Dwivedi, Prashant Povel; Choi, Hee Joo; Kim, Byoung Joo; Cha, Myoungsik

2013-12-16

Random duty-cycle errors (RDE) in ferroelectric quasi-phase-matching (QPM) devices not only affect the frequency conversion efficiency, but also generate non-phase-matched parasitic noise that can be detrimental to some applications. We demonstrate an accurate but simple method for measuring the RDE in periodically poled lithium niobate. Due to the equivalence between the undepleted harmonic generation spectrum and the diffraction pattern from the QPM grating, we employed linear diffraction measurement which is much simpler than tunable harmonic generation experiments [J. S. Pelc, et al., Opt. Lett.36, 864-866 (2011)]. As a result, we could relate the RDE for the QPM device to the relative noise intensity between the diffraction orders.

Pseudo-Random Number Generator Based on Coupled Map Lattices

Science.gov (United States)

Lü, Huaping; Wang, Shihong; Hu, Gang

A one-way coupled chaotic map lattice is used for generating pseudo-random numbers. It is shown that with suitable cooperative applications of both chaotic and conventional approaches, the output of the spatiotemporally chaotic system can easily meet the practical requirements of random numbers, i.e., excellent random statistical properties, long periodicity of computer realizations, and fast speed of random number generations. This pseudo-random number generator system can be used as ideal synchronous and self-synchronizing stream cipher systems for secure communications.

A universal algorithm to generate pseudo-random numbers based on uniform mapping as homeomorphism

International Nuclear Information System (INIS)

Fu-Lai, Wang

2010-01-01

A specific uniform map is constructed as a homeomorphism mapping chaotic time series into [0,1] to obtain sequences of standard uniform distribution. With the uniform map, a chaotic orbit and a sequence orbit obtained are topologically equivalent to each other so the map can preserve the most dynamic properties of chaotic systems such as permutation entropy. Based on the uniform map, a universal algorithm to generate pseudo random numbers is proposed and the pseudo random series is tested to follow the standard 0–1 random distribution both theoretically and experimentally. The algorithm is not complex, which does not impose high requirement on computer hard ware and thus computation speed is fast. The method not only extends the parameter spaces but also avoids the drawback of small function space caused by constraints on chaotic maps used to generate pseudo random numbers. The algorithm can be applied to any chaotic system and can produce pseudo random sequence of high quality, thus can be a good universal pseudo random number generator. (general)

A universal algorithm to generate pseudo-random numbers based on uniform mapping as homeomorphism

Science.gov (United States)

Wang, Fu-Lai

2010-09-01

A specific uniform map is constructed as a homeomorphism mapping chaotic time series into [0,1] to obtain sequences of standard uniform distribution. With the uniform map, a chaotic orbit and a sequence orbit obtained are topologically equivalent to each other so the map can preserve the most dynamic properties of chaotic systems such as permutation entropy. Based on the uniform map, a universal algorithm to generate pseudo random numbers is proposed and the pseudo random series is tested to follow the standard 0-1 random distribution both theoretically and experimentally. The algorithm is not complex, which does not impose high requirement on computer hard ware and thus computation speed is fast. The method not only extends the parameter spaces but also avoids the drawback of small function space caused by constraints on chaotic maps used to generate pseudo random numbers. The algorithm can be applied to any chaotic system and can produce pseudo random sequence of high quality, thus can be a good universal pseudo random number generator.

Does level of specificity affect measures of motivation to comply? A randomized evaluation.

Science.gov (United States)

Branscum, Paul; Senkowski, Valerie

2018-05-30

The theory of planned behavior (TPB) is a popular value-expectancy model in social and behavioral health. Motivation to comply, one of the theory's constructs, has not been well operationalized and measured in the past, and to date, there has been no assessment of whether level of specificity affects the measurement of the construct. The purpose of this study was to measure the motivation to comply construct across four domains (from general to TACT-behavior specific) and evaluate the potential impact the differences have when identifying determinants of generalized injunctive norms. Students (n = 234) attending a large southwestern university completed a TPB survey related to sleep and physical activity, and were randomized to one of four domains that measured motivation to comply (General domain, n = 58; Health domain, n = 60; Behavioral domain, n = 56; and TACT domain, n = 60). Across both behaviors, motivation to comply measurements did not appear to be affected by changing the level of specificity. Referents for sleep and physical activity were mostly significant, but the effects were small to medium. Future researchers should consider removing motivation to comply measures from TPB surveys to reduce respondent burden or find alternative ways of measuring the construct.

Internet-Based Acceptance and Commitment Therapy for Psychological Distress Experienced by People With Hearing Problems: Study Protocol for a Randomized Controlled Trial.

Science.gov (United States)

Molander, Peter; Hesser, Hugo; Weineland, Sandra; Bergwall, Kajsa; Buck, Sonia; Hansson-Malmlöf, Johan; Lantz, Henning; Lunner, Thomas; Andersson, Gerhard

2015-09-01

Psychological distress and psychiatric symptoms are prevalent among people with hearing loss or other audiological conditions, but psychological interventions for these groups are rare. This article describes the study protocol for a randomized controlled trial for evaluating the effect of a psychological treatment delivered over the Internet for individuals with hearing problems and concurrent psychological distress. Participants who are significantly distressed will be randomized to either an 8-week Internet-delivered acceptance-based cognitive behavioral therapy (i.e., acceptance and commitment therapy [ACT]), or wa it-list control. We aim to include measures of distress associated with hearing difficulties, anxiety, and depression. In addition, we aim to measure acceptance associated with hearing difficulties as well as quality of life. The results of the trial may further our understanding of how to best treat people who present problems with both psychological distress and hearing in using the Internet.

Reinforcing Sampling Distributions through a Randomization-Based Activity for Introducing ANOVA

Science.gov (United States)

Taylor, Laura; Doehler, Kirsten

2015-01-01

This paper examines the use of a randomization-based activity to introduce the ANOVA F-test to students. The two main goals of this activity are to successfully teach students to comprehend ANOVA F-tests and to increase student comprehension of sampling distributions. Four sections of students in an advanced introductory statistics course…

Assessing the predictive capability of randomized tree-based ensembles in streamflow modelling

Science.gov (United States)

Galelli, S.; Castelletti, A.

2013-07-01

Combining randomization methods with ensemble prediction is emerging as an effective option to balance accuracy and computational efficiency in data-driven modelling. In this paper, we investigate the prediction capability of extremely randomized trees (Extra-Trees), in terms of accuracy, explanation ability and computational efficiency, in a streamflow modelling exercise. Extra-Trees are a totally randomized tree-based ensemble method that (i) alleviates the poor generalisation property and tendency to overfitting of traditional standalone decision trees (e.g. CART); (ii) is computationally efficient; and, (iii) allows to infer the relative importance of the input variables, which might help in the ex-post physical interpretation of the model. The Extra-Trees potential is analysed on two real-world case studies - Marina catchment (Singapore) and Canning River (Western Australia) - representing two different morphoclimatic contexts. The evaluation is performed against other tree-based methods (CART and M5) and parametric data-driven approaches (ANNs and multiple linear regression). Results show that Extra-Trees perform comparatively well to the best of the benchmarks (i.e. M5) in both the watersheds, while outperforming the other approaches in terms of computational requirement when adopted on large datasets. In addition, the ranking of the input variable provided can be given a physically meaningful interpretation.

A random network based, node attraction facilitated network evolution method

Directory of Open Access Journals (Sweden)

WenJun Zhang

2016-03-01

Full Text Available In present study, I present a method of network evolution that based on random network, and facilitated by node attraction. In this method, I assume that the initial network is a random network, or a given initial network. When a node is ready to connect, it tends to link to the node already owning the most connections, which coincides with the general rule (Barabasi and Albert, 1999 of node connecting. In addition, a node may randomly disconnect a connection i.e., the addition of connections in the network is accompanied by the pruning of some connections. The dynamics of network evolution is determined of the attraction factor Lamda of nodes, the probability of node connection, the probability of node disconnection, and the expected initial connectance. The attraction factor of nodes, the probability of node connection, and the probability of node disconnection are time and node varying. Various dynamics can be achieved by adjusting these parameters. Effects of simplified parameters on network evolution are analyzed. The changes of attraction factor Lamda can reflect various effects of the node degree on connection mechanism. Even the changes of Lamda only will generate various networks from the random to the complex. Therefore, the present algorithm can be treated as a general model for network evolution. Modeling results show that to generate a power-law type of network, the likelihood of a node attracting connections is dependent upon the power function of the node's degree with a higher-order power. Matlab codes for simplified version of the method are provided.

Dissemination of Evidence-Based Antipsychotic Prescribing Guidelines to Nursing Homes: A Cluster Randomized Trial.

Science.gov (United States)

Tjia, Jennifer; Field, Terry; Mazor, Kathleen; Lemay, Celeste A; Kanaan, Abir O; Donovan, Jennifer L; Briesacher, Becky A; Peterson, Daniel; Pandolfi, Michelle; Spenard, Ann; Gurwitz, Jerry H

2015-07-01

To evaluate the effectiveness of efforts to translate and disseminate evidence-based guidelines about atypical antipsychotic use to nursing homes (NHs). Three-arm, cluster randomized trial. NHs. NHs in the state of Connecticut. Evidence-based guidelines for atypical antipsychotic prescribing were translated into a toolkit targeting NH stakeholders, and 42 NHs were recruited and randomized to one of three toolkit dissemination strategies: mailed toolkit delivery (minimal intensity); mailed toolkit delivery with quarterly audit and feedback reports about facility-level antipsychotic prescribing (moderate intensity); and in-person toolkit delivery with academic detailing, on-site behavioral management training, and quarterly audit and feedback reports (high intensity). Outcomes were evaluated using the Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework. Toolkit awareness of 30% (7/23) of leadership of low-intensity NHs, 54% (19/35) of moderate-intensity NHs, and 82% (18/22) of high-intensity NHs reflected adoption and implementation of the intervention. Highest levels of use and knowledge among direct care staff were reported in high-intensity NHs. Antipsychotic prescribing levels declined during the study period, but there were no statistically significant differences between study arms or from secular trends. RE-AIM indicators suggest some success in disseminating the toolkit and differences in reach, adoption, and implementation according to dissemination strategy but no measurable effect on antipsychotic prescribing trends. Further dissemination to external stakeholders such as psychiatry consultants and hospitals may be needed to influence antipsychotic prescribing for NH residents. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

Quantum supremacy in constant-time measurement-based computation: A unified architecture for sampling and verification

Science.gov (United States)

Miller, Jacob; Sanders, Stephen; Miyake, Akimasa

2017-12-01

While quantum speed-up in solving certain decision problems by a fault-tolerant universal quantum computer has been promised, a timely research interest includes how far one can reduce the resource requirement to demonstrate a provable advantage in quantum devices without demanding quantum error correction, which is crucial for prolonging the coherence time of qubits. We propose a model device made of locally interacting multiple qubits, designed such that simultaneous single-qubit measurements on it can output probability distributions whose average-case sampling is classically intractable, under similar assumptions as the sampling of noninteracting bosons and instantaneous quantum circuits. Notably, in contrast to these previous unitary-based realizations, our measurement-based implementation has two distinctive features. (i) Our implementation involves no adaptation of measurement bases, leading output probability distributions to be generated in constant time, independent of the system size. Thus, it could be implemented in principle without quantum error correction. (ii) Verifying the classical intractability of our sampling is done by changing the Pauli measurement bases only at certain output qubits. Our usage of random commuting quantum circuits in place of computationally universal circuits allows a unique unification of sampling and verification, so they require the same physical resource requirements in contrast to the more demanding verification protocols seen elsewhere in the literature.

A robust random number generator based on differential comparison of chaotic laser signals.

Science.gov (United States)

Zhang, Jianzhong; Wang, Yuncai; Liu, Ming; Xue, Lugang; Li, Pu; Wang, Anbang; Zhang, Mingjiang

2012-03-26

We experimentally realize a robust real-time random number generator by differentially comparing the signal from a chaotic semiconductor laser and its delayed signal through a 1-bit analog-to-digital converter. The probability density distribution of the output chaotic signal based on the differential comparison method possesses an extremely small coefficient of Pearson's median skewness (1.5 × 10⁻⁶), which can yield a balanced random sequence much easily than the previously reported method that compares the signal from the chaotic laser with a certain threshold value. Moveover, we experimently demonstrate that our method can stably generate good random numbers at rates of 1.44 Gbit/s with excellent immunity from external perturbations while the previously reported method fails.

The Effectiveness of Web-Based Asthma Self-Management System, My Asthma Portal (MAP): A Pilot Randomized Controlled Trial.

Science.gov (United States)

Ahmed, Sara; Ernst, Pierre; Bartlett, Susan J; Valois, Marie-France; Zaihra, Tasneem; Paré, Guy; Grad, Roland; Eilayyan, Owis; Perreault, Robert; Tamblyn, Robyn

2016-12-01

Whether Web-based technologies can improve disease self-management is uncertain. My Asthma Portal (MAP) is a Web-based self-management support system that couples evidence-based behavioral change components (self-monitoring of symptoms, physical activity, and medication adherence) with real-time monitoring, feedback, and support from a nurse case manager. The aim of this study was to compare the impact of access to a Web-based asthma self-management patient portal linked to a case-management system (MAP) over 6 months compared with usual care on asthma control and quality of life. A multicenter, parallel, 2-arm, pilot, randomized controlled trial was conducted with 100 adults with confirmed diagnosis of asthma from 2 specialty clinics. Asthma control was measured using an algorithm based on overuse of fast-acting bronchodilators and emergency department visits, and asthma-related quality of life was assessed using the Mini-Asthma Quality of Life Questionnaire (MAQLQ). Secondary mediating outcomes included asthma symptoms, depressive symptoms, self-efficacy, and beliefs about medication. Process evaluations were also included. A total of 49 individuals were randomized to MAP and 51 to usual care. Compared with usual care, participants in the intervention group reported significantly higher asthma quality of life (mean change 0.61, 95% CI 0.03 to 1.19), and the change in asthma quality of life for the intervention group between baseline and 3 months (mean change 0.66, 95% CI 0.35 to 0.98) was not seen in the control group. No significant differences in asthma quality of life were found between the intervention and control groups at 6 (mean change 0.46, 95% CI -0.12 to 1.05) and 9 months (mean change 0.39, 95% CI -0.2 to 0.98). For poor control status, there was no significant effect of group, time, or group by time. For all self-reported measures, the intervention group had a significantly higher proportion of individuals, demonstrating a minimal clinically

BWIP-RANDOM-SAMPLING, Random Sample Generation for Nuclear Waste Disposal

International Nuclear Information System (INIS)

Sagar, B.

1989-01-01

1 - Description of program or function: Random samples for different distribution types are generated. Distribution types as required for performance assessment modeling of geologic nuclear waste disposal are provided. These are: - Uniform, - Log-uniform (base 10 or natural), - Normal, - Lognormal (base 10 or natural), - Exponential, - Bernoulli, - User defined continuous distribution. 2 - Method of solution: A linear congruential generator is used for uniform random numbers. A set of functions is used to transform the uniform distribution to the other distributions. Stratified, rather than random, sampling can be chosen. Truncated limits can be specified on many distributions, whose usual definition has an infinite support. 3 - Restrictions on the complexity of the problem: Generation of correlated random variables is not included

A randomized clinical trial in preterm infants on the effects of a home-based early intervention with the 'CareToy System'

DEFF Research Database (Denmark)

Sgandurra, Giuseppina; Lorentzen, Jakob; Inguaggiato, Emanuela

2017-01-01

and visual development in preterm infants. 41 preterm infants (range age: 3.0-5.9 months of corrected age) were enrolled and randomized into two groups, CareToy and Standard Care. 19 infants randomized in CareToy group performed a 4-week CareToy program, while 22 allocated to control group completed 4 weeks......CareToy system is an innovative tele-rehabilitative tool, useful in providing intensive, individualized, home-based, family-centred Early Intervention (EI) in infants. Our aim was to evaluate, through a Randomized Clinical Trial (RCT) study, the effects of CareToy intervention on early motor...... of Standard Care. Infant Motor Profile (IMP) was primary outcome measure, Alberta Infant Motor Scale (AIMS) and Teller Acuity Cards were secondary ones. Assessments were carried out at baseline (T0) and at the end of CareToy training or Standard Care period (T1). T1 was the primary endpoint. After RCT phase...

Calculating radiotherapy margins based on Bayesian modelling of patient specific random errors

International Nuclear Information System (INIS)

Herschtal, A; Te Marvelde, L; Mengersen, K; Foroudi, F; Ball, D; Devereux, T; Pham, D; Greer, P B; Pichler, P; Eade, T; Kneebone, A; Bell, L; Caine, H; Hindson, B; Kron, T; Hosseinifard, Z

2015-01-01

Collected real-life clinical target volume (CTV) displacement data show that some patients undergoing external beam radiotherapy (EBRT) demonstrate significantly more fraction-to-fraction variability in their displacement (‘random error’) than others. This contrasts with the common assumption made by historical recipes for margin estimation for EBRT, that the random error is constant across patients. In this work we present statistical models of CTV displacements in which random errors are characterised by an inverse gamma (IG) distribution in order to assess the impact of random error variability on CTV-to-PTV margin widths, for eight real world patient cohorts from four institutions, and for different sites of malignancy. We considered a variety of clinical treatment requirements and penumbral widths. The eight cohorts consisted of a total of 874 patients and 27 391 treatment sessions. Compared to a traditional margin recipe that assumes constant random errors across patients, for a typical 4 mm penumbral width, the IG based margin model mandates that in order to satisfy the common clinical requirement that 90% of patients receive at least 95% of prescribed RT dose to the entire CTV, margins be increased by a median of 10% (range over the eight cohorts −19% to +35%). This substantially reduces the proportion of patients for whom margins are too small to satisfy clinical requirements. (paper)

Post-stratification based on a choice of a randomization device

Directory of Open Access Journals (Sweden)

Sarjinder Singh

2014-06-01

Full Text Available In this paper, we use the idea of post-stratification based on the respondents’ choice of a particular randomization device in order to estimate the population proportion of a sensitive characteristic. The proposed idea gives full freedom to the respondents and is expected to result in greater cooperation from them as well as to provide some increase in the relative efficiency of the newly proposed estimator.

A permutation test to analyse systematic bias and random measurement errors of medical devices via boosting location and scale models.

Science.gov (United States)

Mayr, Andreas; Schmid, Matthias; Pfahlberg, Annette; Uter, Wolfgang; Gefeller, Olaf

2017-06-01

Measurement errors of medico-technical devices can be separated into systematic bias and random error. We propose a new method to address both simultaneously via generalized additive models for location, scale and shape (GAMLSS) in combination with permutation tests. More precisely, we extend a recently proposed boosting algorithm for GAMLSS to provide a test procedure to analyse potential device effects on the measurements. We carried out a large-scale simulation study to provide empirical evidence that our method is able to identify possible sources of systematic bias as well as random error under different conditions. Finally, we apply our approach to compare measurements of skin pigmentation from two different devices in an epidemiological study.

Random walk term weighting for information retrieval

DEFF Research Database (Denmark)

Blanco, R.; Lioma, Christina

2007-01-01

We present a way of estimating term weights for Information Retrieval (IR), using term co-occurrence as a measure of dependency between terms.We use the random walk graph-based ranking algorithm on a graph that encodes terms and co-occurrence dependencies in text, from which we derive term weights...

[Effects of a neuropsychology program based on mindfulness on Alzheimer's disease: randomized double-blind clinical study].

Science.gov (United States)

Quintana Hernández, Domingo Jesús; Miró Barrachina, María Teresa; Ibáñez Fernández, Ignacio; del Pino, Angelo Santana; García Rodríguez, Javie r; Hernández, Jaime Rojas

2014-01-01

The purpose of this research was to assess effects of a mindfulness based neuropsychological intervention on the clinical course of Alzheimer's disease. A two year randomized and double blind clinical trial was conducted on 127 probable Alzheimer's disease patients, according to NINCDS-ADRDA scale. Patients were grouped into three experimental groups (cognitive stimulation, progressive muscular relaxation, and mindfulness) plus a control group. All participants were receiving donepezil. Cognitive skills were assessed with CAMCOG and MMSE, functional area with RDRS-2, and NPI was used for psychopathology screening. Three treatment sessions per week were carried out for two years, and follow up measurements were taken every six months. The global cognitive function, functionality and behavioral disorders measurements indicated that patients from the experimental group based on mindfulness were stable during the two years, while patients from the control group, as well as the other experimental groups, showed a mild but significant worsening of their mental capacities. The mindfulness based neuropsychological program showed better cognitive and functional stability, as well as significant improvement in the psychopathological condition of mild to moderate Alzheimer' patients. These results support the idea that a mindfulness based intervention can produce a clinically relevant improvement in the treatment of dementia. More research is needed to confirm these data. Copyright © 2013 SEGG. Published by Elsevier Espana. All rights reserved.

Observational attachment theory-based parenting measures predict children's attachment narratives independently from social learning theory-based measures.

Science.gov (United States)

Matias, Carla; O'Connor, Thomas G; Futh, Annabel; Scott, Stephen

2014-01-01

Conceptually and methodologically distinct models exist for assessing quality of parent-child relationships, but few studies contrast competing models or assess their overlap in predicting developmental outcomes. Using observational methodology, the current study examined the distinctiveness of attachment theory-based and social learning theory-based measures of parenting in predicting two key measures of child adjustment: security of attachment narratives and social acceptance in peer nominations. A total of 113 5-6-year-old children from ethnically diverse families participated. Parent-child relationships were rated using standard paradigms. Measures derived from attachment theory included sensitive responding and mutuality; measures derived from social learning theory included positive attending, directives, and criticism. Child outcomes were independently-rated attachment narrative representations and peer nominations. Results indicated that Attachment theory-based and Social Learning theory-based measures were modestly correlated; nonetheless, parent-child mutuality predicted secure child attachment narratives independently of social learning theory-based measures; in contrast, criticism predicted peer-nominated fighting independently of attachment theory-based measures. In young children, there is some evidence that attachment theory-based measures may be particularly predictive of attachment narratives; however, no single model of measuring parent-child relationships is likely to best predict multiple developmental outcomes. Assessment in research and applied settings may benefit from integration of different theoretical and methodological paradigms.

Random Access for Machine-Type Communication based on Bloom Filtering

DEFF Research Database (Denmark)

Pratas, Nuno; Stefanovic, Cedomir; Madueño, Germán Corrales

2016-01-01

utilizes the system resources more efficiently and achieves similar or lower latency of connection establishment in case of synchronous arrivals, compared to the variant of the LTE-A access protocol that is optimized for MTC traffic. A dividend of the proposed method is that allows the base station (BS......We present a random access method inspired on Bloom filters that is suited for Machine-Type Communications (MTC). Each accessing device sends a signature during the contention process. A signature is constructed using the Bloom filtering method and contains information on the device identity...... and the connection establishment cause. We instantiate the proposed method over the current LTE-A access protocol. However, the method is applicable to a more general class of random access protocols that use preambles or other reservation sequences, as expected to be the case in 5G systems. We show that our method...

Multi-parameter sensor based on random fiber lasers

Directory of Open Access Journals (Sweden)

Yanping Xu

2016-09-01

Full Text Available We demonstrate a concept of utilizing random fiber lasers to achieve multi-parameter sensing. The proposed random fiber ring laser consists of an erbium-doped fiber as the gain medium and a random fiber grating as the feedback. The random feedback is effectively realized by a large number of reflections from around 50000 femtosecond laser induced refractive index modulation regions over a 10cm standard single mode fiber. Numerous polarization-dependent spectral filters are formed and superimposed to provide multiple lasing lines with high signal-to-noise ratio up to 40dB, which gives an access for a high-fidelity multi-parameter sensing scheme. The number of sensing parameters can be controlled by the number of the lasing lines via input polarizations and wavelength shifts of each peak can be explored for the simultaneous multi-parameter sensing with one sensing probe. In addition, the random grating induced coupling between core and cladding modes can be potentially used for liquid medical sample sensing in medical diagnostics, biology and remote sensing in hostile environments.

Simulation-based camera navigation training in laparoscopy-a randomized trial

DEFF Research Database (Denmark)

Nilsson, Cecilia; Sørensen, Jette Led; Konge, Lars

2017-01-01

patient safety. The objectives of this trial were to examine how to train laparoscopic camera navigation and to explore the transfer of skills to the operating room. MATERIALS AND METHODS: A randomized, single-center superiority trial with three groups: The first group practiced simulation-based camera...... navigation tasks (camera group), the second group practiced performing a simulation-based cholecystectomy (procedure group), and the third group received no training (control group). Participants were surgical novices without prior laparoscopic experience. The primary outcome was assessment of camera.......033), had a higher score. CONCLUSIONS: Simulation-based training improves the technical skills required for camera navigation, regardless of practicing camera navigation or the procedure itself. Transfer to the clinical setting could, however, not be demonstrated. The control group demonstrated higher...

Random Forest-Based Recognition of Isolated Sign Language Subwords Using Data from Accelerometers and Surface Electromyographic Sensors.

Science.gov (United States)

Su, Ruiliang; Chen, Xiang; Cao, Shuai; Zhang, Xu

2016-01-14

Sign language recognition (SLR) has been widely used for communication amongst the hearing-impaired and non-verbal community. This paper proposes an accurate and robust SLR framework using an improved decision tree as the base classifier of random forests. This framework was used to recognize Chinese sign language subwords using recordings from a pair of portable devices worn on both arms consisting of accelerometers (ACC) and surface electromyography (sEMG) sensors. The experimental results demonstrated the validity of the proposed random forest-based method for recognition of Chinese sign language (CSL) subwords. With the proposed method, 98.25% average accuracy was obtained for the classification of a list of 121 frequently used CSL subwords. Moreover, the random forests method demonstrated a superior performance in resisting the impact of bad training samples. When the proportion of bad samples in the training set reached 50%, the recognition error rate of the random forest-based method was only 10.67%, while that of a single decision tree adopted in our previous work was almost 27.5%. Our study offers a practical way of realizing a robust and wearable EMG-ACC-based SLR systems.

Morphological changes after pelvic floor muscle training measured by 3-dimensional ultrasonography: a randomized controlled trial.

Science.gov (United States)

Braekken, Ingeborg Hoff; Hoff Braekken, Ingeborg; Majida, Memona; Engh, Marie Ellström; Bø, Kari

2010-02-01

To investigate morphological and functional changes after pelvic floor muscle training in women with pelvic organ prolapse. This randomized controlled trial was conducted at a university hospital and a physical therapy clinic. One hundred nine women with pelvic organ prolapse stages I, II, and III were randomly allocated by a computer-generated random number system to pelvic floor muscle training (n=59) or control (n=50). Both groups received lifestyle advice and learned to contract the pelvic floor muscles before and during increases in intraabdominal pressure. In addition the pelvic floor muscle training group did individual strength training with a physical therapist and daily home exercise for 6 months. Primary outcome measures were pelvic floor muscle (pubovisceral muscle) thickness, levator hiatus area, pubovisceral muscle length at rest and Valsalva, and resting position of bladder and rectum, measured by three-dimensional ultrasonography. Seventy-nine percent of women in the pelvic floor muscle training group adhered to at least 80% of the training protocol. Compared with women in the control group, women in the pelvic floor muscle training group increased muscle thickness (difference between groups: 1.9 mm, 95% confidence interval [CI] 1.1-2.7, Ppelvic floor muscle stiffness. Supervised pelvic floor muscle training can increase muscle volume, close the levator hiatus, shorten muscle length, and elevate the resting position of the bladder and rectum. www.clinicaltrials.gov, NCT00271297. I.

Effectiveness of a theory-based intervention to increase colorectal cancer screening among Iranian health club members: a randomized trial.

Science.gov (United States)

Salimzadeh, Hamideh; Eftekhar, Hassan; Majdzadeh, Reza; Montazeri, Ali; Delavari, Alireza

2014-10-01

Colorectal cancer is the third most commonly diagnosed cancer and the fourth leading cause of death in the world. There are few published studies that have used theory-based interventions designed to increase colorectal cancer screening in community lay health organizations. The present study was guided by the theoretical concepts of the preventive health model. Twelve health clubs of a municipal district in Tehran were randomized to two study groups with equal ratio. The control group received usual services throughout the study while the intervention group also received a theory-based educational program on colorectal cancer screening plus a reminder call. Screening behavior, the main outcome, was assessed 4 months after randomization. A total of 360 members aged 50 and older from 12 health clubs completed a baseline survey. Participants in the intervention group reported increased knowledge of colorectal cancer and screening tests at 4 months follow-up (p's theory-based intervention significantly improved self-efficacy, perceived susceptibility, efficacy of screening, social support, and intention to be screened for colorectal cancer, from baseline to 4 months follow-up (p's theory-based intervention was found to have a significant effect on colorectal cancer screening use as measured by self-report. The findings could have implications for colorectal cancer screening program development and implementation in primary health care settings and through other community organizations.

Self-Powered Random Number Generator Based on Coupled Triboelectric and Electrostatic Induction Effects at the Liquid-Dielectric Interface.

Science.gov (United States)

Yu, Aifang; Chen, Xiangyu; Cui, Haotian; Chen, Libo; Luo, Jianjun; Tang, Wei; Peng, Mingzeng; Zhang, Yang; Zhai, Junyi; Wang, Zhong Lin

2016-12-27

Modern cryptography increasingly employs random numbers generated from physical sources in lieu of conventional software-based pseudorandom numbers, primarily owing to the great demand of unpredictable, indecipherable cryptographic keys from true random numbers for information security. Thus, far, the sole demonstration of true random numbers has been generated through thermal noise and/or quantum effects, which suffers from expensive and complex equipment. In this paper, we demonstrate a method for self-powered creation of true random numbers by using triboelectric technology to collect random signals from nature. This random number generator based on coupled triboelectric and electrostatic induction effects at the liquid-dielectric interface includes an elaborately designed triboelectric generator (TENG) with an irregular grating structure, an electronic-optical device, and an optical-electronic device. The random characteristics of raindrops are harvested through TENG and consequently transformed and converted by electronic-optical device and an optical-electronic device with a nonlinear characteristic. The cooperation of the mechanical, electrical, and optical signals ensures that the generator possesses complex nonlinear input-output behavior and contributes to increased randomness. The random number sequences are deduced from final electrical signals received by an optical-electronic device using a familiar algorithm. These obtained random number sequences exhibit good statistical characteristics, unpredictability, and unrepeatability. Our study supplies a simple, practical, and effective method to generate true random numbers, which can be widely used in cryptographic protocols, digital signatures, authentication, identification, and other information security fields.

ERROR DISTRIBUTION EVALUATION OF THE THIRD VANISHING POINT BASED ON RANDOM STATISTICAL SIMULATION

Directory of Open Access Journals (Sweden)

C. Li

2012-07-01

Full Text Available POS, integrated by GPS / INS (Inertial Navigation Systems, has allowed rapid and accurate determination of position and attitude of remote sensing equipment for MMS (Mobile Mapping Systems. However, not only does INS have system error, but also it is very expensive. Therefore, in this paper error distributions of vanishing points are studied and tested in order to substitute INS for MMS in some special land-based scene, such as ground façade where usually only two vanishing points can be detected. Thus, the traditional calibration approach based on three orthogonal vanishing points is being challenged. In this article, firstly, the line clusters, which parallel to each others in object space and correspond to the vanishing points, are detected based on RANSAC (Random Sample Consensus and parallelism geometric constraint. Secondly, condition adjustment with parameters is utilized to estimate nonlinear error equations of two vanishing points (VX, VY. How to set initial weights for the adjustment solution of single image vanishing points is presented. Solving vanishing points and estimating their error distributions base on iteration method with variable weights, co-factor matrix and error ellipse theory. Thirdly, under the condition of known error ellipses of two vanishing points (VX, VY and on the basis of the triangle geometric relationship of three vanishing points, the error distribution of the third vanishing point (VZ is calculated and evaluated by random statistical simulation with ignoring camera distortion. Moreover, Monte Carlo methods utilized for random statistical estimation are presented. Finally, experimental results of vanishing points coordinate and their error distributions are shown and analyzed.

Error Distribution Evaluation of the Third Vanishing Point Based on Random Statistical Simulation

Science.gov (United States)

Li, C.

2012-07-01

POS, integrated by GPS / INS (Inertial Navigation Systems), has allowed rapid and accurate determination of position and attitude of remote sensing equipment for MMS (Mobile Mapping Systems). However, not only does INS have system error, but also it is very expensive. Therefore, in this paper error distributions of vanishing points are studied and tested in order to substitute INS for MMS in some special land-based scene, such as ground façade where usually only two vanishing points can be detected. Thus, the traditional calibration approach based on three orthogonal vanishing points is being challenged. In this article, firstly, the line clusters, which parallel to each others in object space and correspond to the vanishing points, are detected based on RANSAC (Random Sample Consensus) and parallelism geometric constraint. Secondly, condition adjustment with parameters is utilized to estimate nonlinear error equations of two vanishing points (VX, VY). How to set initial weights for the adjustment solution of single image vanishing points is presented. Solving vanishing points and estimating their error distributions base on iteration method with variable weights, co-factor matrix and error ellipse theory. Thirdly, under the condition of known error ellipses of two vanishing points (VX, VY) and on the basis of the triangle geometric relationship of three vanishing points, the error distribution of the third vanishing point (VZ) is calculated and evaluated by random statistical simulation with ignoring camera distortion. Moreover, Monte Carlo methods utilized for random statistical estimation are presented. Finally, experimental results of vanishing points coordinate and their error distributions are shown and analyzed.

Randomized Trial of ConquerFear: A Novel, Theoretically Based Psychosocial Intervention for Fear of Cancer Recurrence.

Science.gov (United States)

Butow, Phyllis N; Turner, Jane; Gilchrist, Jemma; Sharpe, Louise; Smith, Allan Ben; Fardell, Joanna E; Tesson, Stephanie; O'Connell, Rachel; Girgis, Afaf; Gebski, Val J; Asher, Rebecca; Mihalopoulos, Cathrine; Bell, Melanie L; Zola, Karina Grunewald; Beith, Jane; Thewes, Belinda

2017-12-20

Purpose Fear of cancer recurrence (FCR) is prevalent, distressing, and long lasting. This study evaluated the impact of a theoretically/empirically based intervention (ConquerFear) on FCR. Methods Eligible survivors had curable breast or colorectal cancer or melanoma, had completed treatment (not including endocrine therapy) 2 months to 5 years previously, were age > 18 years, and had scores above the clinical cutoff on the FCR Inventory (FCRI) severity subscale at screening. Participants were randomly assigned at a one-to-one ratio to either five face-to-face sessions of ConquerFear (attention training, metacognitions, acceptance/mindfulness, screening behavior, and values-based goal setting) or an attention control (Taking-it-Easy relaxation therapy). Participants completed questionnaires at baseline (T0), immediately post-therapy (T1), and 3 (T2) and 6 months (T3) later. The primary outcome was FCRI total score. Results Of 704 potentially eligible survivors from 17 sites and two online databases, 533 were contactable, of whom 222 (42%) consented; 121 were randomly assigned to intervention and 101 to control. Study arms were equivalent at baseline on all measured characteristics. ConquerFear participants had clinically and statistically greater improvements than control participants from T0 to T1 on FCRI total ( P psychological distress, and triggers) as well as in general anxiety, cancer-specific distress (total), and mental quality of life and metacognitions (total). Differences in FCRI psychological distress and cancer-specific distress (total) remained significantly different at T3. Conclusion This randomized trial demonstrated efficacy of ConquerFear compared with attention control (Taking-it-Easy) in reduction of FCRI total scores immediately post-therapy and 3 and 6 months later and in many secondary outcomes immediately post-therapy. Cancer-specific distress (total) remained more improved at 3- and 6-month follow-up.

Estimation of beam material random field properties via sensitivity-based model updating using experimental frequency response functions

Science.gov (United States)

Machado, M. R.; Adhikari, S.; Dos Santos, J. M. C.; Arruda, J. R. F.

2018-03-01

Structural parameter estimation is affected not only by measurement noise but also by unknown uncertainties which are present in the system. Deterministic structural model updating methods minimise the difference between experimentally measured data and computational prediction. Sensitivity-based methods are very efficient in solving structural model updating problems. Material and geometrical parameters of the structure such as Poisson's ratio, Young's modulus, mass density, modal damping, etc. are usually considered deterministic and homogeneous. In this paper, the distributed and non-homogeneous characteristics of these parameters are considered in the model updating. The parameters are taken as spatially correlated random fields and are expanded in a spectral Karhunen-Loève (KL) decomposition. Using the KL expansion, the spectral dynamic stiffness matrix of the beam is expanded as a series in terms of discretized parameters, which can be estimated using sensitivity-based model updating techniques. Numerical and experimental tests involving a beam with distributed bending rigidity and mass density are used to verify the proposed method. This extension of standard model updating procedures can enhance the dynamic description of structural dynamic models.

A Randomized Controlled Trial of COMPASS Web-Based and Face-to-Face Teacher Coaching in Autism

Science.gov (United States)

Ruble, Lisa A.; McGrew, John H.; Toland, Michael D.; Dalrymple, Nancy J.; Jung, Lee Ann

2013-01-01

Objective Most children with autism rely on schools as their primary source of intervention, yet research has suggested that teachers rarely use evidence-based practices. To address the need for improved educational outcomes, a previously tested consultation intervention called the Collaborative Model for Promoting Competence and Success (COMPASS; Ruble, Dalrymple, & McGrew, 2010; Ruble, Dalrymple, & McGrew, 2012) was evaluated in a 2nd randomized controlled trial, with the addition of a web-based group. Method Forty-nine teacher–child dyads were randomized into 1 of 3 groups: (1) a placebo control (PBO) group, (2) COMPASS followed by face-to-face (FF) coaching sessions, and (3) COMPASS followed by web-based (WEB) coaching sessions. Three individualized goals (social, communication, and independence skills) were selected for intervention for each child. The primary outcome of independent ratings of child goal attainment and several process measures (e.g., consultant and teacher fidelity) were evaluated. Results Using an intent-to-treat approach, findings replicated earlier results with a very large effect size (d = 1.41) for the FF group and a large effect size (d = 1.12) for the WEB group relative to the PBO group. There were no differences in overall change across goal domains between the FF and WEB groups, suggesting the efficacy of videoconferencing technology. Conclusions COMPASS is effective and results in improved educational outcomes for young children with autism. Videoconferencing technology, as a scalable tool, has promise for facilitating access to autism specialists and bridging the research-to-practice gap. PMID:23438314

A Unified 3D Mesh Segmentation Framework Based on Markov Random Field

OpenAIRE

Z.F. Shi; L.Y. Lu; D. Le; X.M. Niu

2012-01-01

3D Mesh segmentation has become an important research field in computer graphics during the past decades. Many geometry based and semantic oriented approaches for 3D mesh segmentation has been presented. In this paper, we present a definition of mesh segmentation according to labeling problem. Inspired by the Markov Random Field (MRF) based image segmentation, we propose a new framework of 3D mesh segmentation based on MRF and use graph cuts to solve it. Any features of 3D mesh can be integra...

Home-based family intervention increases knowledge, communication and living donation rates: a randomized controlled trial.

Science.gov (United States)

Ismail, S Y; Luchtenburg, A E; Timman, R; Zuidema, W C; Boonstra, C; Weimar, W; Busschbach, J J V; Massey, E K

2014-08-01

Our aim was to develop and test an educational program to support well-informed decision making among patients and their social network regarding living donor kidney transplantation (LDKT). One hundred sixty-three patients who were unable to find a living donor were randomized to standard care or standard care plus home-based education. In the education condition, patients and members of their social network participated in home-based educational meetings and discussed renal replacement therapy options. Patients and invitees completed pre-post self-report questionnaires measuring knowledge, risk perception, communication, self-efficacy and subjective norm. LDKT activities were observed for 6 months postintervention. Patients in the experimental group showed significantly more improvements in knowledge (p communication (p = 0.012) compared with the control group. The invitees showed pre-post increases in knowledge (p decision making and promotes access to LDKT. © Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.

Markov chain beam randomization: a study of the impact of PLANCK beam measurement errors on cosmological parameter estimation

Science.gov (United States)

Rocha, G.; Pagano, L.; Górski, K. M.; Huffenberger, K. M.; Lawrence, C. R.; Lange, A. E.

2010-04-01

We introduce a new method to propagate uncertainties in the beam shapes used to measure the cosmic microwave background to cosmological parameters determined from those measurements. The method, called markov chain beam randomization (MCBR), randomly samples from a set of templates or functions that describe the beam uncertainties. The method is much faster than direct numerical integration over systematic “nuisance” parameters, and is not restricted to simple, idealized cases as is analytic marginalization. It does not assume the data are normally distributed, and does not require Gaussian priors on the specific systematic uncertainties. We show that MCBR properly accounts for and provides the marginalized errors of the parameters. The method can be generalized and used to propagate any systematic uncertainties for which a set of templates is available. We apply the method to the Planck satellite, and consider future experiments. Beam measurement errors should have a small effect on cosmological parameters as long as the beam fitting is performed after removal of 1/f noise.

Physically transient photonics: random versus distributed feedback lasing based on nanoimprinted DNA.

Science.gov (United States)

Camposeo, Andrea; Del Carro, Pompilio; Persano, Luana; Cyprych, Konrad; Szukalski, Adam; Sznitko, Lech; Mysliwiec, Jaroslaw; Pisignano, Dario

2014-10-28

Room-temperature nanoimprinted, DNA-based distributed feedback (DFB) laser operation at 605 nm is reported. The laser is made of a pure DNA host matrix doped with gain dyes. At high excitation densities, the emission of the untextured dye-doped DNA films is characterized by a broad emission peak with an overall line width of 12 nm and superimposed narrow peaks, characteristic of random lasing. Moreover, direct patterning of the DNA films is demonstrated with a resolution down to 100 nm, enabling the realization of both surface-emitting and edge-emitting DFB lasers with a typical line width of <0.3 nm. The resulting emission is polarized, with a ratio between the TE- and TM-polarized intensities exceeding 30. In addition, the nanopatterned devices dissolve in water within less than 2 min. These results demonstrate the possibility of realizing various physically transient nanophotonics and laser architectures, including random lasing and nanoimprinted devices, based on natural biopolymers.

An experimental comparison of triggered and random pulse train uncertainties

International Nuclear Information System (INIS)

Henzlova, Daniela; Menlove, Howard O.; Swinhoe, Martyn T.

2010-01-01

In this paper we present an experimental comparison of signal-triggered and randomly triggered based analysis algorithms of neutron multiplicity data. Traditional shift register type signal-triggered multiplicity analysis of singles, doubles and triples rates is compared with analysis using randomly triggered gates. Two methods of random gate generation are explored - non-overlapping gates (Feyrunan approach) and periodic overlapping gates (fast accidentals). Using californium sources with low, medium and high rate in combination with AmLi sources (as a surrogate for plutonium) we investigate relative standard deviation (RSD) of data in order to determine if there are parameter spaces in which one of the measurement methods should be preferred. Neutron correlation analysis is a commonly used NDA technique to assay plutonium mass. The data can be collected in two distinct ways: using signal-triggered or randomly triggered counting gates. Analysis algorithms were developed for both approaches to determine singles (S), doubles (D) and triples (7) rates from the measured sample. Currently the most commonly implemented technique to collect neutron coincidence data utilizes shift register based electronics. Shift register uses signal-triggered counting gates to generate foreground multiplicity distribution of correlated+accidental events and a random gate (opened after a predefined long delay following the signal trigger) to generate background multiplicity distribution of accidental events. Modern shift registers include fast accidental option to sample data with a fixed clock frequency. This way a set of overlapping gates is used to generate background multiplicity distributions in order to improve the measurement precision. In parallel to shift register approach the Feynman variance technique is frequently used, which utilizes set of consecutive non-overlapping gates. In general, different user communities (e.g. safeguards, nuclear material accountancy, emergency

Accounting for randomness in measurement and sampling in studying cancer cell population dynamics.

Science.gov (United States)

Ghavami, Siavash; Wolkenhauer, Olaf; Lahouti, Farshad; Ullah, Mukhtar; Linnebacher, Michael

2014-10-01

Knowing the expected temporal evolution of the proportion of different cell types in sample tissues gives an indication about the progression of the disease and its possible response to drugs. Such systems have been modelled using Markov processes. We here consider an experimentally realistic scenario in which transition probabilities are estimated from noisy cell population size measurements. Using aggregated data of FACS measurements, we develop MMSE and ML estimators and formulate two problems to find the minimum number of required samples and measurements to guarantee the accuracy of predicted population sizes. Our numerical results show that the convergence mechanism of transition probabilities and steady states differ widely from the real values if one uses the standard deterministic approach for noisy measurements. This provides support for our argument that for the analysis of FACS data one should consider the observed state as a random variable. The second problem we address is about the consequences of estimating the probability of a cell being in a particular state from measurements of small population of cells. We show how the uncertainty arising from small sample sizes can be captured by a distribution for the state probability.

Efficacy of Internet-Based Guided Treatment for Genito-Pelvic Pain/Penetration Disorder: Rationale, Treatment Protocol, and Design of a Randomized Controlled Trial

Directory of Open Access Journals (Sweden)

Anna-Carlotta Zarski

2018-01-01

Full Text Available IntroductionGenito-pelvic pain/penetration disorder (GPPPD not only adversely affects women’s sexuality and sexual satisfaction but is also associated with a wide range of psychosocial consequences such as reduced quality of life and well-being, mental health comorbidities, and relationship distress. Evidence for effective treatment options is scarce.AimThis article describes the rationale, treatment protocol, and study design for a randomized controlled trial examining the efficacy of an Internet-based guided intervention for GPPPD.MethodTwo hundred women who meet the criteria for GPPPD and have not been able to experience sexual intercourse for at least the last 6 months will be recruited and randomly assigned either to the intervention group (IG or a 6-month waitlist control group. Assessments take place at baseline (T1, peritreatment after completion of Session 5 in IG (T2, after completion of Session 8 or 12 weeks after randomization (T3, and after 6 months (T4. Data will be analyzed on an intention-to-treat and a completer basis.Main outcome measuresThe primary outcome will be sexual intercourse involving the insertion of the partner’s penis at posttreatment. Secondary outcomes include, e.g., improved non-intercourse penetration, sexual functioning, dyadic stress coping, reduced fear of sexuality and negative penetration-related cognitions. Fear of sexuality, penetration-related cognitions, and exercise intensity will be assessed as mediators of intercourse in the IG. Sexual dysfunctions of partners will be measured at baseline (T1 and investigated as a potential moderator of the primary treatment outcome.DiscussionGiven the burden associated with GPPPD and the need for specialized treatment, there is a surprising lack of evidence-based treatment options. This study aims to assess whether Internet-based interventions could contribute to closing this treatment gap.Clinical Trial RegistrationGerman Register of Clinical Studies (DRKS

Light-reflection random-target method for measurement of the modulation transfer function of a digital video-camera

Science.gov (United States)

Pospisil, J.; Jakubik, P.; Machala, L.

2005-11-01

This article reports the suggestion, realization and verification of the newly developed measuring means of the noiseless and locally shift-invariant modulation transfer function (MTF) of a digital video camera in a usual incoherent visible region of optical intensity, especially of its combined imaging, detection, sampling and digitizing steps which are influenced by the additive and spatially discrete photodetector, aliasing and quantization noises. Such means relates to the still camera automatic working regime and static two-dimensional spatially continuous light-reflection random target of white-noise property. The introduced theoretical reason for such a random-target method is also performed under exploitation of the proposed simulation model of the linear optical intensity response and possibility to express the resultant MTF by a normalized and smoothed rate of the ascertainable output and input power spectral densities. The random-target and resultant image-data were obtained and processed by means of a processing and evaluational PC with computation programs developed on the basis of MATLAB 6.5E The present examples of results and other obtained results of the performed measurements demonstrate the sufficient repeatability and acceptability of the described method for comparative evaluations of the performance of digital video cameras under various conditions.

Fault diagnosis in spur gears based on genetic algorithm and random forest

Science.gov (United States)

Cerrada, Mariela; Zurita, Grover; Cabrera, Diego; Sánchez, René-Vinicio; Artés, Mariano; Li, Chuan

2016-03-01

There are growing demands for condition-based monitoring of gearboxes, and therefore new methods to improve the reliability, effectiveness, accuracy of the gear fault detection ought to be evaluated. Feature selection is still an important aspect in machine learning-based diagnosis in order to reach good performance of the diagnostic models. On the other hand, random forest classifiers are suitable models in industrial environments where large data-samples are not usually available for training such diagnostic models. The main aim of this research is to build up a robust system for the multi-class fault diagnosis in spur gears, by selecting the best set of condition parameters on time, frequency and time-frequency domains, which are extracted from vibration signals. The diagnostic system is performed by using genetic algorithms and a classifier based on random forest, in a supervised environment. The original set of condition parameters is reduced around 66% regarding the initial size by using genetic algorithms, and still get an acceptable classification precision over 97%. The approach is tested on real vibration signals by considering several fault classes, one of them being an incipient fault, under different running conditions of load and velocity.

Internet-based guided self-help for posttraumatic stress disorder (PTSD): Randomized controlled trial.

Science.gov (United States)

Lewis, Catrin E; Farewell, Daniel; Groves, Vicky; Kitchiner, Neil J; Roberts, Neil P; Vick, Tracey; Bisson, Jonathan I

2017-06-01

There are numerous barriers that limit access to evidence-based treatment for posttraumatic stress disorder (PTSD). Internet-based guided self-help is a treatment option that may help widen access to effective intervention, but the approach has not been sufficiently explored for the treatment of PTSD. Forty two adults with DSM-5 PTSD of mild to moderate severity were randomly allocated to internet-based self-help with up to 3 h of therapist assistance, or to a delayed treatment control group. The internet-based program included eight modules that focused on psychoeducation, grounding, relaxation, behavioural activation, real-life and imaginal exposure, cognitive therapy, and relapse prevention. The primary outcome measure was reduction in clinician-rated traumatic stress symptoms using the clinician administered PTSD scale for DSM-V (CAPS-5). Secondary outcomes were self-reported PTSD symptoms, depression, anxiety, alcohol use, perceived social support, and functional impairment. Posttreatment, the internet-based guided self-help group had significantly lower clinician assessed PTSD symptoms than the delayed treatment control group (between-group effect size Cohen's d = 1.86). The difference was maintained at 1-month follow-up and dissipated once both groups had received treatment. Similar patterns of difference between the two groups were found for depression, anxiety, and functional impairment. The average contact with treating clinicians was 2½ h. Internet-based trauma-focused guided self-help for PTSD is a promising treatment option that requires far less therapist time than current first line face-to-face psychological therapy. © 2017 Wiley Periodicals, Inc.

Using a web-based game to prevent posttraumatic stress in children following medical events: design of a randomized controlled trial.

Science.gov (United States)

Marsac, Meghan L; Kohser, Kristen L; Winston, Flaura K; Kenardy, Justin; March, Sonja; Kassam-Adams, Nancy

2013-01-01

Medical events including acute illness and injury are among the most common potentially traumatic experiences for children. Despite the scope of the problem, only limited resources are available for prevention of posttraumatic stress symptoms (PTSS) after pediatric medical events. Web-based programs provide a low-cost, accessible means to reach a wide range of families and show promise in related areas of child mental health. To describe the design of a randomized controlled trial that will evaluate feasibility and estimate preliminary efficacy of Coping Coach, a web-based preventive intervention to prevent or reduce PTSS after acute pediatric medical events. Seventy children and their parents will be randomly assigned to either an intervention or a waitlist control condition. Inclusion criteria require that children are aged 8-12 years, have experienced a medical event, have access to Internet and telephone, and have sufficient competency in the English language to complete measures and understand the intervention. Participants will complete baseline measures and will then be randomized to the intervention or waitlist control condition. Children in the intervention condition will complete module 1 (Feelings Identification) in the hospital and will be instructed on how to complete modules 2 (Appraisals) and 3 (Avoidance) online. Follow-up assessments will be conducted via telephone at 6, 12, and 18 weeks after the baseline assessment. Following the 12-week assessment, children in the waitlist control condition will receive instructions for completing the intervention. Primary study outcomes include data on intervention feasibility and outcomes (child appraisals, coping, PTSS and health-related quality of life). Results will provide data on the feasibility of the implementation of the Coping Coach intervention and study procedures as well as estimations of efficacy to determine sample size for a larger study. Potential strengths and limitations of this design are

Using a web-based game to prevent posttraumatic stress in children following medical events: design of a randomized controlled trial

Directory of Open Access Journals (Sweden)

Nancy Kassam-Adams

2013-07-01

Full Text Available Background: Medical events including acute illness and injury are among the most common potentially traumatic experiences for children. Despite the scope of the problem, only limited resources are available for prevention of posttraumatic stress symptoms (PTSS after pediatric medical events. Web-based programs provide a low-cost, accessible means to reach a wide range of families and show promise in related areas of child mental health. Objectives: To describe the design of a randomized controlled trial that will evaluate feasibility and estimate preliminary efficacy of Coping Coach, a web-based preventive intervention to prevent or reduce PTSS after acute pediatric medical events. Method: Seventy children and their parents will be randomly assigned to either an intervention or a waitlist control condition. Inclusion criteria require that children are aged 8–12 years, have experienced a medical event, have access to Internet and telephone, and have sufficient competency in the English language to complete measures and understand the intervention. Participants will complete baseline measures and will then be randomized to the intervention or waitlist control condition. Children in the intervention condition will complete module 1 (Feelings Identification in the hospital and will be instructed on how to complete modules 2 (Appraisals and 3 (Avoidance online. Follow-up assessments will be conducted via telephone at 6, 12, and 18 weeks after the baseline assessment. Following the 12-week assessment, children in the waitlist control condition will receive instructions for completing the intervention. Results: Primary study outcomes include data on intervention feasibility and outcomes (child appraisals, coping, PTSS and health-related quality of life. Discussion: Results will provide data on the feasibility of the implementation of the Coping Coach intervention and study procedures as well as estimations of efficacy to determine sample size for a

DNA based random key generation and management for OTP encryption.

Science.gov (United States)

Zhang, Yunpeng; Liu, Xin; Sun, Manhui

2017-09-01

One-time pad (OTP) is a principle of key generation applied to the stream ciphering method which offers total privacy. The OTP encryption scheme has proved to be unbreakable in theory, but difficult to realize in practical applications. Because OTP encryption specially requires the absolute randomness of the key, its development has suffered from dense constraints. DNA cryptography is a new and promising technology in the field of information security. DNA chromosomes storing capabilities can be used as one-time pad structures with pseudo-random number generation and indexing in order to encrypt the plaintext messages. In this paper, we present a feasible solution to the OTP symmetric key generation and transmission problem with DNA at the molecular level. Through recombinant DNA technology, by using only sender-receiver known restriction enzymes to combine the secure key represented by DNA sequence and the T vector, we generate the DNA bio-hiding secure key and then place the recombinant plasmid in implanted bacteria for secure key transmission. The designed bio experiments and simulation results show that the security of the transmission of the key is further improved and the environmental requirements of key transmission are reduced. Analysis has demonstrated that the proposed DNA-based random key generation and management solutions are marked by high security and usability. Published by Elsevier B.V.

Teaching of evidence-based medicine to medical students in Mexico: a randomized controlled trial

Directory of Open Access Journals (Sweden)

Sánchez-Mendiola Melchor

2012-11-01

Full Text Available Abstract Background Evidence-Based Medicine (EBM is an important competency for the healthcare professional. Experimental evidence of EBM educational interventions from rigorous research studies is limited. The main objective of this study was to assess EBM learning (knowledge, attitudes and self-reported skills in undergraduate medical students with a randomized controlled trial. Methods The educational intervention was a one-semester EBM course in the 5th year of a public medical school in Mexico. The study design was an experimental parallel group randomized controlled trial for the main outcome measures in the 5th year class (M5 EBM vs. M5 non-EBM groups, and quasi-experimental with static-groups comparisons for the 4th year (M4, not yet exposed and 6th year (M6, exposed 6 months to a year earlier groups. EBM attitudes, knowledge and self-reported skills were measured using Taylor’s questionnaire and a summative exam which comprised of a 100-item multiple-choice question (MCQ test. Results 289 Medical students were assessed: M5 EBM=48, M5 non-EBM=47, M4=87, and M6=107. There was a higher reported use of the Cochrane Library and secondary journals in the intervention group (M5 vs. M5 non-EBM. Critical appraisal skills and attitude scores were higher in the intervention group (M5 and in the group of students exposed to EBM instruction during the previous year (M6. The knowledge level was higher after the intervention in the M5 EBM group compared to the M5 non-EBM group (pd=0.88 with Taylor's instrument and 3.54 with the 100-item MCQ test. M6 Students that received the intervention in the previous year had a knowledge score higher than the M4 and M5 non-EBM groups, but lower than the M5 EBM group. Conclusions Formal medical student training in EBM produced higher scores in attitudes, knowledge and self-reported critical appraisal skills compared with a randomized control group. Data from the concurrent groups add validity evidence to the

High-Tg Polynorbornene-Based Block and Random Copolymers for Butanol Pervaporation Membranes

Science.gov (United States)

Register, Richard A.; Kim, Dong-Gyun; Takigawa, Tamami; Kashino, Tomomasa; Burtovyy, Oleksandr; Bell, Andrew

Vinyl addition polymers of substituted norbornene (NB) monomers possess desirably high glass transition temperatures (Tg); however, until very recently, the lack of an applicable living polymerization chemistry has precluded the synthesis of such polymers with controlled architecture, or copolymers with controlled sequence distribution. We have recently synthesized block and random copolymers of NB monomers bearing hydroxyhexafluoroisopropyl and n-butyl substituents (HFANB and BuNB) via living vinyl addition polymerization with Pd-based catalysts. Both series of polymers were cast into the selective skin layers of thin film composite (TFC) membranes, and these organophilic membranes investigated for the isolation of n-butanol from dilute aqueous solution (model fermentation broth) via pervaporation. The block copolymers show well-defined microphase-separated morphologies, both in bulk and as the selective skin layers on TFC membranes, while the random copolymers are homogeneous. Both block and random vinyl addition copolymers are effective as n-butanol pervaporation membranes, with the block copolymers showing a better flux-selectivity balance. While polyHFANB has much higher permeability and n-butanol selectivity than polyBuNB, incorporating BuNB units into the polymer (in either a block or random sequence) limits the swelling of the polyHFANB and thereby improves the n-butanol pervaporation selectivity.

An effective approach to attenuate random noise based on compressive sensing and curvelet transform

International Nuclear Information System (INIS)

Liu, Wei; Cao, Siyuan; Zu, Shaohuan; Chen, Yangkang

2016-01-01

Random noise attenuation is an important step in seismic data processing. In this paper, we propose a novel denoising approach based on compressive sensing and the curvelet transform. We formulate the random noise attenuation problem as an L _1 norm regularized optimization problem. We propose to use the curvelet transform as the sparse transform in the optimization problem to regularize the sparse coefficients in order to separate signal and noise and to use the gradient projection for sparse reconstruction (GPSR) algorithm to solve the formulated optimization problem with an easy implementation and a fast convergence. We tested the performance of our proposed approach on both synthetic and field seismic data. Numerical results show that the proposed approach can effectively suppress the distortion near the edge of seismic events during the noise attenuation process and has high computational efficiency compared with the traditional curvelet thresholding and iterative soft thresholding based denoising methods. Besides, compared with f-x deconvolution, the proposed denoising method is capable of eliminating the random noise more effectively while preserving more useful signals. (paper)

A mindfulness-based stress prevention training for medical students (MediMind): study protocol for a randomized controlled trial.

Science.gov (United States)

Kuhlmann, Sophie Merle; Bürger, Arne; Esser, Günter; Hammerle, Florian

2015-02-08

Medical training is very demanding and associated with a high prevalence of psychological distress. Compared to the general population, medical students are at a greater risk of developing a psychological disorder. Various attempts of stress management training in medical school have achieved positive results on minimizing psychological distress; however, there are often limitations. Therefore, the use of a rigorous scientific method is needed. The present study protocol describes a randomized controlled trial to examine the effectiveness of a specifically developed mindfulness-based stress prevention training for medical students that includes selected elements of cognitive behavioral strategies (MediMind). This study protocol presents a prospective randomized controlled trial, involving four assessment time points: baseline, post-intervention, one-year follow-up and five-year follow-up. The aims include evaluating the effect on stress, coping, psychological morbidity and personality traits with validated measures. Participants are allocated randomly to one of three conditions: MediMind, Autogenic Training or control group. Eligible participants are medical or dental students in the second or eighth semester of a German university. They form a population of approximately 420 students in each academic term. A final total sample size of 126 (at five-year follow-up) is targeted. The trainings (MediMind and Autogenic Training) comprise five weekly sessions lasting 90 minutes each. MediMind will be offered to participants of the control group once the five-year follow-up is completed. The allotment is randomized with a stratified allocation ratio by course of studies, semester, and gender. After descriptive statistics have been evaluated, inferential statistical analysis will be carried out with a repeated measures ANOVA-design with interactions between time and group. Effect sizes will be calculated using partial η-square values. Potential limitations of this study

Effects of language of assessment on the measurement of acculturation: measurement equivalence and cultural frame switching.

Science.gov (United States)

Schwartz, Seth J; Benet-Martínez, Verónica; Knight, George P; Unger, Jennifer B; Zamboanga, Byron L; Des Rosiers, Sabrina E; Stephens, Dionne P; Huang, Shi; Szapocznik, José

2014-03-01

The present study used a randomized design, with fully bilingual Hispanic participants from the Miami area, to investigate 2 sets of research questions. First, we sought to ascertain the extent to which measures of acculturation (Hispanic and U.S. practices, values, and identifications) satisfied criteria for linguistic measurement equivalence. Second, we sought to examine whether cultural frame switching would emerge--that is, whether latent acculturation mean scores for U.S. acculturation would be higher among participants randomized to complete measures in English and whether latent acculturation mean scores for Hispanic acculturation would be higher among participants randomized to complete measures in Spanish. A sample of 722 Hispanic students from a Hispanic-serving university participated in the study. Participants were first asked to complete translation tasks to verify that they were fully bilingual. Based on ratings from 2 independent coders, 574 participants (79.5% of the sample) qualified as fully bilingual and were randomized to complete the acculturation measures in either English or Spanish. Theoretically relevant criterion measures--self-esteem, depressive symptoms, and personal identity--were also administered in the randomized language. Measurement equivalence analyses indicated that all of the acculturation measures--Hispanic and U.S. practices, values, and identifications-met criteria for configural, weak/metric, strong/scalar, and convergent validity equivalence. These findings indicate that data generated using acculturation measures can, at least under some conditions, be combined or compared across languages of administration. Few latent mean differences emerged. These results are discussed in terms of the measurement of acculturation in linguistically diverse populations. 2014 APA

Application of Vector Triggering Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

result is a Random Decrement function from each measurement. In traditional Random Decrement estimation the triggering condition is a scalar condition, which should only be fulfilled in a single measurement. In vector triggering Random Decrement the triggering condition is a vector condition......This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented...... in this paper should be regarded as a further documentation of the technique. The key point in Random Decrement estimation is the formulation of a triggering condition. If the triggering condition is fulfilled a time segment from each measurement is picked out and averaged with previous time segments. The final...

Application of Vector Triggering Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

1997-01-01

result is a Random Decrement function from each measurement. In traditional Random Decrement estimation the triggering condition is a scalar condition, which should only be fulfilled in a single measurement. In vector triggering Random Decrement the triggering condition is a vector condition......This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented...... in this paper should be regarded as a further documentation of the technique. The key point in Random Decrement estimation is the formulation of a triggering condition. If the triggering condition is fulfilled a time segment from each measurement is picked out and averaged with previous time segments. The final...

Status of radiation-based measurement technology

International Nuclear Information System (INIS)

Moon, B. S.; Lee, J. W.; Chung, C. E.; Hong, S. B.; Kim, J. T.; Park, W. M.; Kim, J. Y.

1999-03-01

This report describes the status of measurement equipment using radiation source and new technologies in this field. This report includes the development status in Korea together with a brief description of the technology development and application status in ten countries including France, America, and Japan. Also this report describes technical factors related to radiation-based measurement and trends of new technologies. Measurement principles are also described for the equipment that is widely used among radiation-based measurement, such as level measurement, density measurement, basis weight measurement, moisture measurement, and thickness measurement. (author). 7 refs., 2 tabs., 21 figs

Personality predicts drop-out from therapist-guided internet-based cognitive behavioural therapy for eating disorders. Results from a randomized controlled trial

Directory of Open Access Journals (Sweden)

Louise Högdahl

2016-09-01

Full Text Available Internet-based guided self-help cognitive behavioural therapy (ICBT seems a promising way of delivering eating disorder treatment. However, treatment drop-out is a common problem and little is known about the correlates, especially in clinical settings. The study aimed to explore prediction of drop-out in the context of a randomized controlled trial within specialized eating disorder care in terms of eating disorder symptomatology, personality traits, comorbidity, and demographic characteristics. 109 outpatients diagnosed with bulimia nervosa or similar eating disorder were randomized to two types of ICBT. Participants were assessed with several clinical- and self-ratings. The average drop-out rate was 36%. Drop-out was predicted by lower scores in the personality traits Dutifulness and Assertiveness as measured by the NEO Personality Inventory Revised, and by higher scores in Self-affirm as measured by the Structural Analysis of Social Behaviour. Drop-out was also predicted by therapist factors: one therapist had significantly more drop-outs (82% than the other three (M = 30%. Theoretical and clinical implications of the impact of the predictors are discussed.

Pseudo random number generator based on quantum chaotic map

Science.gov (United States)

Akhshani, A.; Akhavan, A.; Mobaraki, A.; Lim, S.-C.; Hassan, Z.

2014-01-01

For many years dissipative quantum maps were widely used as informative models of quantum chaos. In this paper, a new scheme for generating good pseudo-random numbers (PRNG), based on quantum logistic map is proposed. Note that the PRNG merely relies on the equations used in the quantum chaotic map. The algorithm is not complex, which does not impose high requirement on computer hardware and thus computation speed is fast. In order to face the challenge of using the proposed PRNG in quantum cryptography and other practical applications, the proposed PRNG is subjected to statistical tests using well-known test suites such as NIST, DIEHARD, ENT and TestU01. The results of the statistical tests were promising, as the proposed PRNG successfully passed all these tests. Moreover, the degree of non-periodicity of the chaotic sequences of the quantum map is investigated through the Scale index technique. The obtained result shows that, the sequence is more non-periodic. From these results it can be concluded that, the new scheme can generate a high percentage of usable pseudo-random numbers for simulation and other applications in scientific computing.

Influence of low ambient temperature on epitympanic temperature measurement: a prospective randomized clinical study.

Science.gov (United States)

Strapazzon, Giacomo; Procter, Emily; Putzer, Gabriel; Avancini, Giovanni; Dal Cappello, Tomas; Überbacher, Norbert; Hofer, Georg; Rainer, Bernhard; Rammlmair, Georg; Brugger, Hermann

2015-11-05

Epitympanic temperature (Tty) measured with thermistor probes correlates with core body temperature (Tcore), but the reliability of measurements at low ambient temperature is unknown. The aim of this study was to determine if commercially-available thermistor-based Tty reflects Tcore in low ambient temperature and if Tty is influenced by insulation of the ear. Thirty-one participants (two females) were exposed to room (23.2 ± 0.4 °C) and low (-18.7 ± 1.0 °C) ambient temperature for 10 min using a randomized cross-over design. Tty was measured using an epitympanic probe (M1024233, GE Healthcare Finland Oy) and oesophageal temperature (Tes) with an oesophageal probe (M1024229, GE Healthcare Finland Oy) inserted into the lower third of the oesophagus. Ten participants wore ear protectors (Arton 2200, Emil Lux GmbH & Co. KG, Wermelskirchen, Switzerland) to insulate the ear from ambient air. During exposure to room temperature, mean Tty increased from 33.4 ± 1.5 to 34.2 ± 0.8 °C without insulation of the ear and from 35.0 ± 0.8 to 35.5 ± 0.7 °C with insulation. During exposure to low ambient temperature, mean Tty decreased from 32.4 ± 1.6 to 28.5 ± 2.0 °C without insulation and from 35.6 ± 0.6 to 35.2 ± 0.9 °C with insulation. The difference between Tty and Tes at low ambient temperature was reduced by 82% (from 7.2 to 1.3 °C) with insulation of the ear. Epitympanic temperature measurements are influenced by ambient temperature and deviate from Tes at room and low ambient temperature. Insulating the ear with ear protectors markedly reduced the difference between Tty and Tes and improved the stability of measurements. The use of models to correct Tty may be possible, but results should be validated in larger studies.

Guided Web-Based Cognitive Behavior Therapy for Perfectionism: Results From Two Different Randomized Controlled Trials.

Science.gov (United States)

Rozental, Alexander; Shafran, Roz; Wade, Tracey D; Kothari, Radha; Egan, Sarah J; Ekberg, Linda; Wiss, Maria; Carlbring, Per; Andersson, Gerhard

2018-04-26

Perfectionism can become a debilitating condition that may negatively affect functioning in multiple areas, including mental health. Prior research has indicated that internet-based cognitive behavioral therapy can be beneficial, but few studies have included follow-up data. The objective of this study was to explore the outcomes at follow-up of internet-based cognitive behavioral therapy with guided self-help, delivered as 2 separate randomized controlled trials conducted in Sweden and the United Kingdom. In total, 120 participants randomly assigned to internet-based cognitive behavioral therapy were included in both intention-to-treat and completer analyses: 78 in the Swedish trial and 62 in the UK trial. The primary outcome measure was the Frost Multidimensional Perfectionism Scale, Concern over Mistakes subscale (FMPS CM). Secondary outcome measures varied between the trials and consisted of the Clinical Perfectionism Questionnaire (CPQ; both trials), the 9-item Patient Health Questionnaire (PHQ-9; Swedish trial), the 7-item Generalized Anxiety Disorder scale (GAD-7; Swedish trial), and the 21-item Depression Anxiety Stress Scale (DASS-21; UK trial). Follow-up occurred after 6 months for the UK trial and after 12 months for the Swedish trial. Analysis of covariance revealed a significant difference between pretreatment and follow-up in both studies. Intention-to-treat within-group Cohen d effect sizes were 1.21 (Swedish trial; 95% CI 0.86-1.54) and 1.24 (UK trial; 95% CI 0.85-1.62) for the FMPS CM. Furthermore, 29 (59%; Swedish trial) and 15 (43%; UK trial) of the participants met the criteria for recovery on the FMPS CM. Improvements were also significant for the CPQ, with effect sizes of 1.32 (Swedish trial; 95% CI 0.97-1.66) and 1.49 (UK trial; 95% CI 1.09-1.88); the PHQ-9, effect size 0.60 (95% CI 0.28-0.92); the GAD-7, effect size 0.67 (95% CI 0.34-0.99); and the DASS-21, effect size 0.50 (95% CI 0.13-0.85). The results are promising for the use of

Effect of mindfulness-based stress reduction on pain severity and mindful awareness in patients with tension headache: a randomized controlled clinical trial.

Science.gov (United States)

Omidi, Abdollah; Zargar, Fatemeh

2014-09-01

Programs to improve the pain and health status in illnesses with pain such as headache are still in their infancy. Mindfulness-based stress reduction (MBSR) is a new psychotherapy that appears to be effective in treating chronic pain. This study evaluated efficacy of MBSR in improving pain severity and mindful awareness in patients with tension headache. This study was a randomized controlled clinical trial that was conducted in 2012 in Shahid Beheshti Hospital of Kashan City. Sixty patients who were diagnosed with tension-type headache according to the International Headache Classification Subcommittee were randomly assigned to treatment as usual (TAU) or MBSR groups. The MBSR group received eight weekly treatments. Any session lasted 120 minutes. The sessions were based on MBSR protocol. Diary scale for measuring headache and Mindful Attention Awareness Scale (MAAS) were administered at pretreatment, and posttreatment, and three-month follow-up in both groups. The data was analyzed using repeated measures analysis of variance. The mean of pain severity was 7.36 ± 1.25 before intervention that was significantly reduced to 5.62 ± 1.74 and 6.07 ± 1.08 after the intervention and follow-up (P headache. It appears that MBSR is an effective psychotherapy for treatment of patients with tension headache.

Employment-Based Abstinence Reinforcement as a Maintenance Intervention for the Treatment of Cocaine Dependence: A Randomized Controlled Trial

Science.gov (United States)

DeFulio, Anthony; Donlin, Wendy D.; Wong, Conrad J.; Silverman, Kenneth

2009-01-01

Context: Due to the chronic nature of cocaine dependence, long-term maintenance treatments may be required to sustain abstinence. Abstinence reinforcement is among the most effective means of initiating cocaine abstinence. Practical and effective means of maintaining abstinence reinforcement programs over time are needed. Objective: Determine whether employment-based abstinence reinforcement can be an effective long-term maintenance intervention for cocaine dependence. Design: Participants (N=128) were enrolled in a 6-month job skills training and abstinence initiation program. Participants who initiated abstinence, attended regularly, and developed needed job skills during the first six months were hired as operators in a data entry business and randomly assigned to an employment only (Control, n = 24) or abstinence-contingent employment (n = 27) group. Setting: A nonprofit data entry business. Participants: Unemployed welfare recipients who persistently used cocaine while enrolled in methadone treatment in Baltimore. Intervention: Abstinence-contingent employment participants received one year of employment-based contingency management, in which access to employment was contingent on provision drug-free urine samples under routine and then random drug testing. If a participant provided drug-positive urine or failed to provide a mandatory sample, then that participant received a temporary reduction in pay and could not work until urinalysis confirmed recent abstinence. Main Outcome Measure: Cocaine-negative urine samples at monthly assessments across one year of employment. Results: During the one-year of employment, abstinence-contingent employment participants provided significantly more cocaine-negative urine samples than employment only participants (79.3% and 50.7%, respectively; p = 0.004, OR = 3.73, 95% CI = 1.60 – 8.69). Conclusions: Employment-based abstinence reinforcement that includes random drug testing is effective as a long-term maintenance

Effect of an Internet-Based Program on Weight Loss for Low-Income Postpartum Women: A Randomized Clinical Trial.

Science.gov (United States)

Phelan, Suzanne; Hagobian, Todd; Brannen, Anna; Hatley, Karen E; Schaffner, Andrew; Muñoz-Christian, Karen; Tate, Deborah F

2017-06-20

Postpartum weight retention increases lifetime risk of obesity and related morbidity. Few effective interventions exist for multicultural, low-income women. To test whether an internet-based weight loss program in addition to the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC program) for low-income postpartum women could produce greater weight loss than the WIC program alone over 12 months. A 12-month, cluster randomized, assessor-blind, clinical trial enrolling 371 adult postpartum women at 12 clinics in WIC programs from the California central coast between July 2011 and May 2015 with data collection completed in May 2016. Clinics were randomized to the WIC program (standard care group) or the WIC program plus a 12-month primarily internet-based weight loss program (intervention group), including a website with weekly lessons, web diary, instructional videos, computerized feedback, text messages, and monthly face-to-face groups at the WIC clinics. The primary outcome was weight change over 12 months, based on measurements at baseline, 6 months, and 12 months. Secondary outcomes included proportion returning to preconception weight and changes in physical activity and diet. Participants included 371 women (mean age, 28.1 years; Hispanic, 81.6%; mean weight above prepregnancy weight, 7.8 kg; mean months post partum, 5.2 months) randomized to the intervention group (n = 174) or standard care group (n = 197); 89.2% of participants completed the study. The intervention group produced greater mean 12-month weight loss compared with the standard care group (3.2 kg in the intervention group vs 0.9 kg in standard care group, P income postpartum women, an internet-based weight loss program in addition to the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC program) compared with the WIC program alone resulted in a statistically significant greater weight loss over 12 months. Further research is needed to

The Effectiveness of a Web-Based Computer-Tailored Intervention on Workplace Sitting: A Randomized Controlled Trial.

Science.gov (United States)

De Cocker, Katrien; De Bourdeaudhuij, Ilse; Cardon, Greet; Vandelanotte, Corneel

2016-05-31

Effective interventions to influence workplace sitting are needed, as office-based workers demonstrate high levels of continued sitting, and sitting too much is associated with adverse health effects. Therefore, we developed a theory-driven, Web-based, interactive, computer-tailored intervention aimed at reducing and interrupting sitting at work. The objective of our study was to investigate the effects of this intervention on objectively measured sitting time, standing time, and breaks from sitting, as well as self-reported context-specific sitting among Flemish employees in a field-based approach. Employees (n=213) participated in a 3-group randomized controlled trial that assessed outcomes at baseline, 1-month follow-up, and 3-month follow-up through self-reports. A subsample (n=122) were willing to wear an activity monitor (activPAL) from Monday to Friday. The tailored group received an automated Web-based, computer-tailored intervention including personalized feedback and tips on how to reduce or interrupt workplace sitting. The generic group received an automated Web-based generic advice with tips. The control group was a wait-list control condition, initially receiving no intervention. Intervention effects were tested with repeated-measures multivariate analysis of variance. The tailored intervention was successful in decreasing self-reported total workday sitting (time × group: Pleisure time sitting (time × group: P=.03), and in increasing objectively measured breaks at work (time × group: P=.07); this was not the case in the other conditions. The changes in self-reported total nonworkday sitting, sitting during transport, television viewing, and personal computer use, objectively measured total sitting time, and sitting and standing time at work did not differ between conditions. Our results point out the significance of computer tailoring for sedentary behavior and its potential use in public health promotion, as the effects of the tailored condition

Mapping Deforestation in North Korea Using Phenology-Based Multi-Index and Random Forest

Directory of Open Access Journals (Sweden)

Yihua Jin

2016-12-01

Full Text Available Phenology-based multi-index with the random forest (RF algorithm can be used to overcome the shortcomings of traditional deforestation mapping that involves pixel-based classification, such as ISODATA or decision trees, and single images. The purpose of this study was to investigate methods to identify specific types of deforestation in North Korea, and to increase the accuracy of classification, using phenological characteristics extracted with multi-index and random forest algorithms. The mapping of deforestation area based on RF was carried out by merging phenology-based multi-indices (i.e., normalized difference vegetation index (NDVI, normalized difference water index (NDWI, and normalized difference soil index (NDSI derived from MODIS (Moderate Resolution Imaging Spectroradiometer products and topographical variables. Our results showed overall classification accuracy of 89.38%, with corresponding kappa coefficients of 0.87. In particular, for forest and farm land categories with similar phenological characteristic (e.g., paddy, plateau vegetation, unstocked forest, hillside field, this approach improved the classification accuracy in comparison with pixel-based methods and other classes. The deforestation types were identified by incorporating point data from high-resolution imagery, outcomes of image classification, and slope data. Our study demonstrated that the proposed methodology could be used for deciding on the restoration priority and monitoring the expansion of deforestation areas.

An efficient ERP-based brain-computer interface using random set presentation and face familiarity.

Directory of Open Access Journals (Sweden)

Seul-Ki Yeom

Full Text Available Event-related potential (ERP-based P300 spellers are commonly used in the field of brain-computer interfaces as an alternative channel of communication for people with severe neuro-muscular diseases. This study introduces a novel P300 based brain-computer interface (BCI stimulus paradigm using a random set presentation pattern and exploiting the effects of face familiarity. The effect of face familiarity is widely studied in the cognitive neurosciences and has recently been addressed for the purpose of BCI. In this study we compare P300-based BCI performances of a conventional row-column (RC-based paradigm with our approach that combines a random set presentation paradigm with (non- self-face stimuli. Our experimental results indicate stronger deflections of the ERPs in response to face stimuli, which are further enhanced when using the self-face images, and thereby improving P300-based spelling performance. This lead to a significant reduction of stimulus sequences required for correct character classification. These findings demonstrate a promising new approach for improving the speed and thus fluency of BCI-enhanced communication with the widely used P300-based BCI setup.

A 30-month worksite-based lifestyle program to promote cardiovascular health in middle-aged bank employees: Design of the TANSNIP-PESA randomized controlled trial.

Science.gov (United States)

Coffeng, Jennifer K; van der Ploeg, Hidde P; Castellano, José M; Fernández-Alvira, Juan M; Ibáñez, Borja; García-Lunar, Inés; van der Beek, Allard J; Fernández-Ortiz, Antonio; Mocoroa, Agustín; García-Leal, Laura; Cárdenas, Evelyn; Rojas, Carolina; Martínez-Castro, María I; Santiago-Sacristán, Silvia; Fernández-Gallardo, Miriam; Mendiguren, José M; Bansilal, Sameer; van Mechelen, Willem; Fuster, Valentín

2017-02-01

Cardiovascular disease (CVD) is the leading cause of death worldwide. With atherosclerosis as the underlying cause for many CVD events, prevention or reduction of subclinical atherosclerotic plaque burden (SAPB) through a healthier lifestyle may have substantial public health benefits. The objective was to describe the protocol of a randomized controlled trial investigating the effectiveness of a 30-month worksite-based lifestyle program aimed to promote cardiovascular health in participants having a high or a low degree of SAPB compared with standard care. We will conduct a randomized controlled trial including middle-aged bank employees from the Progression of Early Subclinical Atherosclerosis cohort, stratified by SAPB (high SAPB n=260, low SAPB n=590). Within each stratum, participants will be randomized 1:1 to receive a lifestyle program or standard care. The program consists of 3 elements: (a) 12 personalized lifestyle counseling sessions using Motivational Interviewing over a 30-month period, (b) a wrist-worn physical activity tracker, and (c) a sit-stand workstation. Primary outcome measure is a composite score of blood pressure, physical activity, sedentary time, body weight, diet, and smoking (ie, adapted Fuster-BEWAT score) measured at baseline and at 1-, 2-, and 3-year follow-up. The study will provide insights into the effectiveness of a 30-month worksite-based lifestyle program to promote cardiovascular health compared with standard care in participants with a high or low degree of SAPB. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

An audit strategy for time-to-event outcomes measured with error: application to five randomized controlled trials in oncology.

Science.gov (United States)

Dodd, Lori E; Korn, Edward L; Freidlin, Boris; Gu, Wenjuan; Abrams, Jeffrey S; Bushnell, William D; Canetta, Renzo; Doroshow, James H; Gray, Robert J; Sridhara, Rajeshwari

2013-10-01

Measurement error in time-to-event end points complicates interpretation of treatment effects in clinical trials. Non-differential measurement error is unlikely to produce large bias [1]. When error depends on treatment arm, bias is of greater concern. Blinded-independent central review (BICR) of all images from a trial is commonly undertaken to mitigate differential measurement-error bias that may be present in hazard ratios (HRs) based on local evaluations. Similar BICR and local evaluation HRs may provide reassurance about the treatment effect, but BICR adds considerable time and expense to trials. We describe a BICR audit strategy [2] and apply it to five randomized controlled trials to evaluate its use and to provide practical guidelines. The strategy requires BICR on a subset of study subjects, rather than a complete-case BICR, and makes use of an auxiliary-variable estimator. When the effect size is relatively large, the method provides a substantial reduction in the size of the BICRs. In a trial with 722 participants and a HR of 0.48, an average audit of 28% of the data was needed and always confirmed the treatment effect as assessed by local evaluations. More moderate effect sizes and/or smaller trial sizes required larger proportions of audited images, ranging from 57% to 100% for HRs ranging from 0.55 to 0.77 and sample sizes between 209 and 737. The method is developed for a simple random sample of study subjects. In studies with low event rates, more efficient estimation may result from sampling individuals with events at a higher rate. The proposed strategy can greatly decrease the costs and time associated with BICR, by reducing the number of images undergoing review. The savings will depend on the underlying treatment effect and trial size, with larger treatment effects and larger trials requiring smaller proportions of audited data.

A cluster-based randomized controlled trial promoting community participation in arsenic mitigation efforts in Bangladesh

OpenAIRE

George, Christine Marie; van Geen, Alexander; Slavkovich, Vesna; Singha, Ashit; Levy, Diane; Islam, Tariqul; Ahmed, Kazi Matin; Moon-Howard, Joyce; Tarozzi, Alessandro; Liu, Xinhua; Factor-Litvak, Pam; Graziano, Joseph

2012-01-01

Abstract Objective To reduce arsenic (As) exposure, we evaluated the effectiveness of training community members to perform water arsenic (WAs) testing and provide As education compared to sending representatives from outside communities to conduct these tasks. Methods We conducted a cluster based randomized controlled trial of 20 villages in Singair, Bangladesh. Fifty eligible respondents were randomly selected in each village. In 10 villages, a community member provided As education and WAs...

A computer-based measure of resultant achievement motivation.

Science.gov (United States)

Blankenship, V

1987-08-01

Three experiments were conducted to develop a computer-based measure of individual differences in resultant achievement motivation (RAM) on the basis of level-of-aspiration, achievement motivation, and dynamics-of-action theories. In Experiment 1, the number of atypical shifts and greater responsiveness to incentives on 21 trials with choices among easy, intermediate, and difficult levels of an achievement-oriented game were positively correlated and were found to differentiate the 62 subjects (31 men, 31 women) on the amount of time they spent at a nonachievement task (watching a color design) 1 week later. In Experiment 2, test-retest reliability was established with the use of 67 subjects (15 men, 52 women). Point and no-point trials were offered in blocks, with point trials first for half the subjects and no-point trials first for the other half. Reliability was higher for the atypical-shift measure than for the incentive-responsiveness measure and was higher when points were offered first. In Experiment 3, computer anxiety was manipulated by creating a simulated computer breakdown in the experimental condition. Fifty-nine subjects (13 men, 46 women) were randomly assigned to the experimental condition or to one of two control conditions (an interruption condition and a no-interruption condition). Subjects with low RAM, as demonstrated by a low number of typical shifts, took longer to choose the achievement-oriented task, as predicted by the dynamics-of-action theory. The difference was evident in all conditions and most striking in the computer-breakdown condition. A change of focus from atypical to typical shifts is discussed.

Motivational interviewing in a Web-based physical activity intervention with an avatar: randomized controlled trial.

Science.gov (United States)

Friederichs, Stijn; Bolman, Catherine; Oenema, Anke; Guyaux, Janneke; Lechner, Lilian

2014-02-13

Developing Web-based physical activity (PA) interventions based on motivational interviewing (MI) could increase the availability and reach of MI techniques for PA promotion. Integrating an avatar in such an intervention could lead to more positive appreciation and higher efficacy of the intervention, compared to an intervention that is purely text-based. The present study aims to determine whether a Web-based PA intervention based on MI with an avatar results in more positive appreciation and higher effectiveness of the intervention, when compared to an intervention that is purely text-based. A three-arm randomized controlled trial was conducted, containing the following research conditions: (1) a Web-based PA intervention based on MI with an avatar, (2) a content-identical intervention without an avatar, and (3) a control condition that received no intervention. Measurements included PA behavior and process variables, measured at baseline, directly following the intervention and 1 month post intervention. Both interventions significantly increased self-reported PA at 1 month, compared to the control condition (beta(AVATARvsCONTROL)=.39, P=.011; beta(TEXTvsCONTROL)=.44, P=.006). No distinctions were found regarding intervention effect on PA between both interventions. Similarly, the results of the process evaluation did not indicate any significant differences between both interventions. Due to the limited relational skills of the avatar in this study, it probably did not succeed in forming a stronger relationship with the user, over and above text alone. The findings suggest that avatars that do not strengthen the social relationship with the user do not enhance the intervention impact. Future research should determine whether Web-based PA interventions based on MI could benefit from inclusion of a virtual coach capable of more complex relational skills than used in the current study, such as responding in gesture to the user's state and input. Dutch Trial

An Improved Fast Compressive Tracking Algorithm Based on Online Random Forest Classifier

Directory of Open Access Journals (Sweden)

Xiong Jintao

2016-01-01

Full Text Available The fast compressive tracking (FCT algorithm is a simple and efficient algorithm, which is proposed in recent years. But, it is difficult to deal with the factors such as occlusion, appearance changes, pose variation, etc in processing. The reasons are that, Firstly, even if the naive Bayes classifier is fast in training, it is not robust concerning the noise. Secondly, the parameters are required to vary with the unique environment for accurate tracking. In this paper, we propose an improved fast compressive tracking algorithm based on online random forest (FCT-ORF for robust visual tracking. Firstly, we combine ideas with the adaptive compressive sensing theory regarding the weighted random projection to exploit both local and discriminative information of the object. The second reason is the online random forest classifier for online tracking which is demonstrated with more robust to the noise adaptively and high computational efficiency. The experimental results show that the algorithm we have proposed has a better performance in the field of occlusion, appearance changes, and pose variation than the fast compressive tracking algorithm’s contribution.

Model-based cartilage thickness measurement in the submillimeter range

International Nuclear Information System (INIS)

Streekstra, G. J.; Strackee, S. D.; Maas, M.; Wee, R. ter; Venema, H. W.

2007-01-01

Current methods of image-based thickness measurement in thin sheet structures utilize second derivative zero crossings to locate the layer boundaries. It is generally acknowledged that the nonzero width of the point spread function (PSF) limits the accuracy of this measurement procedure. We propose a model-based method that strongly reduces PSF-induced bias by incorporating the PSF into the thickness estimation method. We estimated the bias in thickness measurements in simulated thin sheet images as obtained from second derivative zero crossings. To gain insight into the range of sheet thickness where our method is expected to yield improved results, sheet thickness was varied between 0.15 and 1.2 mm with an assumed PSF as present in the high-resolution modes of current computed tomography (CT) scanners [full width at half maximum (FWHM) 0.5-0.8 mm]. Our model-based method was evaluated in practice by measuring layer thickness from CT images of a phantom mimicking two parallel cartilage layers in an arthrography procedure. CT arthrography images of cadaver wrists were also evaluated, and thickness estimates were compared to those obtained from high-resolution anatomical sections that served as a reference. The thickness estimates from the simulated images reveal that the method based on second derivative zero crossings shows considerable bias for layers in the submillimeter range. This bias is negligible for sheet thickness larger than 1 mm, where the size of the sheet is more than twice the FWHM of the PSF but can be as large as 0.2 mm for a 0.5 mm sheet. The results of the phantom experiments show that the bias is effectively reduced by our method. The deviations from the true thickness, due to random fluctuations induced by quantum noise in the CT images, are of the order of 3% for a standard wrist imaging protocol. In the wrist the submillimeter thickness estimates from the CT arthrography images correspond within 10% to those estimated from the anatomical

Estimating random transverse velocities in the fast solar wind from EISCAT Interplanetary Scintillation measurements

Directory of Open Access Journals (Sweden)

A. Canals

2002-09-01

Full Text Available Interplanetary scintillation measurements can yield estimates of a large number of solar wind parameters, including bulk flow speed, variation in bulk velocity along the observing path through the solar wind and random variation in transverse velocity. This last parameter is of particular interest, as it can indicate the flux of low-frequency Alfvén waves, and the dissipation of these waves has been proposed as an acceleration mechanism for the fast solar wind. Analysis of IPS data is, however, a significantly unresolved problem and a variety of a priori assumptions must be made in interpreting the data. Furthermore, the results may be affected by the physical structure of the radio source and by variations in the solar wind along the scintillation ray path. We have used observations of simple point-like radio sources made with EISCAT between 1994 and 1998 to obtain estimates of random transverse velocity in the fast solar wind. The results obtained with various a priori assumptions made in the analysis are compared, and we hope thereby to be able to provide some indication of the reliability of our estimates of random transverse velocity and the variation of this parameter with distance from the Sun.Key words. Interplanetary physics (MHD waves and turbulence; solar wind plasma; instruments and techniques

Estimating random transverse velocities in the fast solar wind from EISCAT Interplanetary Scintillation measurements

Directory of Open Access Journals (Sweden)

A. Canals

Full Text Available Interplanetary scintillation measurements can yield estimates of a large number of solar wind parameters, including bulk flow speed, variation in bulk velocity along the observing path through the solar wind and random variation in transverse velocity. This last parameter is of particular interest, as it can indicate the flux of low-frequency Alfvén waves, and the dissipation of these waves has been proposed as an acceleration mechanism for the fast solar wind. Analysis of IPS data is, however, a significantly unresolved problem and a variety of a priori assumptions must be made in interpreting the data. Furthermore, the results may be affected by the physical structure of the radio source and by variations in the solar wind along the scintillation ray path. We have used observations of simple point-like radio sources made with EISCAT between 1994 and 1998 to obtain estimates of random transverse velocity in the fast solar wind. The results obtained with various a priori assumptions made in the analysis are compared, and we hope thereby to be able to provide some indication of the reliability of our estimates of random transverse velocity and the variation of this parameter with distance from the Sun.

Key words. Interplanetary physics (MHD waves and turbulence; solar wind plasma; instruments and techniques

Home-based exercise program and fall-risk reduction in older adults with multiple sclerosis: phase 1 randomized controlled trial.

Science.gov (United States)

Sosnoff, Jacob J; Finlayson, Marcia; McAuley, Edward; Morrison, Steve; Motl, Robert W

2014-03-01

To determine the feasibility, safety, and efficacy of a home-based exercise intervention targeting fall risk in older adults with multiple sclerosis. A randomized controlled pilot trial. A home-based exercise program. Participants were randomly allocated to either a home-based exercise intervention group (n = 13) or a waiting list control group (n = 14). The exercise group completed exercises targeting lower muscle strength and balance three times a week for 12 weeks. The control group continued normal activity. Fall risk (Physiological Profile Assessment scores), balance (Berg Balance Scale), and walking testing prior to and immediately following the 12-week intervention. Each outcome measure was placed in an analysis of covariance with group as the between-subject factor and baseline values as the covariate. Effect sizes were calculated. Twelve participants from the control group and ten from the exercise group completed the study. There were no related adverse events. Fall risk was found to decrease in the exercise group following the intervention (1.1 SD 1.0 vs. 0.6 SD 0.6) while there was an increase in fall risk in the control group (1.9 SD 1.5 vs. 2.2 SD 1.9). Effect sizes for most outcomes were large (η(2) > 0.15). Home-based exercise was found to be feasible, safe, and effective for reducing physiological fall risk in older adults with multiple sclerosis. Our findings support the implementation of a larger trial to reduce fall risk in persons with multiple sclerosis.

Incorporating PROMIS Symptom Measures into Primary Care Practice-a Randomized Clinical Trial.

Science.gov (United States)

Kroenke, Kurt; Talib, Tasneem L; Stump, Timothy E; Kean, Jacob; Haggstrom, David A; DeChant, Paige; Lake, Kittie R; Stout, Madison; Monahan, Patrick O

2018-04-05

Symptoms account for more than 400 million clinic visits annually in the USA. The SPADE symptoms (sleep, pain, anxiety, depression, and low energy/fatigue) are particularly prevalent and undertreated. To assess the effectiveness of providing PROMIS (Patient-Reported Outcome Measure Information System) symptom scores to clinicians on symptom outcomes. Randomized clinical trial conducted from March 2015 through May 2016 in general internal medicine and family practice clinics in an academic healthcare system. Primary care patients who screened positive for at least one SPADE symptom. After completing the PROMIS symptom measures electronically immediately prior to their visit, the 300 study participants were randomized to a feedback group in which their clinician received a visual display of symptom scores or a control group in which scores were not provided to clinicians. The primary outcome was the 3-month change in composite SPADE score. Secondary outcomes were individual symptom scores, symptom documentation in the clinic note, symptom-specific clinician actions, and patient satisfaction. Most patients (84%) had multiple clinically significant (T-score ≥ 55) SPADE symptoms. Both groups demonstrated moderate symptom improvement with a non-significant trend favoring the feedback compared to control group (between-group difference in composite T-score improvement, 1.1; P = 0.17). Symptoms present at baseline resolved at 3-month follow-up only one third of the time, and patients frequently still desired treatment. Except for pain, clinically significant symptoms were documented less than half the time. Neither symptom documentation, symptom-specific clinician actions, nor patient satisfaction differed between treatment arms. Predictors of greater symptom improvement included female sex, black race, fewer medical conditions, and receiving care in a family medicine clinic. Simple feedback of symptom scores to primary care clinicians in the absence of

Effects of Video Game Training on Behavioral and Electrophysiological Measures of Attention and Memory: Protocol for a Randomized Controlled Trial.

Science.gov (United States)

Ballesteros, Soledad; Mayas, Julia; Ruiz-Marquez, Eloisa; Prieto, Antonio; Toril, Pilar; Ponce de Leon, Laura; de Ceballos, Maria L; Reales Avilés, José Manuel

2017-01-24

Neuroplasticity-based approaches seem to offer promising ways of maintaining cognitive health in older adults and postponing the onset of cognitive decline symptoms. Although previous research suggests that training can produce transfer effects, this study was designed to overcome some limitations of previous studies by incorporating an active control group and the assessment of training expectations. The main objectives of this study are (1) to evaluate the effects of a randomized computer-based intervention consisting of training older adults with nonaction video games on brain and cognitive functions that decline with age, including attention and spatial working memory, using behavioral measures and electrophysiological recordings (event-related potentials [ERPs]) just after training and after a 6-month no-contact period; (2) to explore whether motivation, engagement, or expectations might account for possible training-related improvements; and (3) to examine whether inflammatory mechanisms assessed with noninvasive measurement of C-reactive protein in saliva impair cognitive training-induced effects. A better understanding of these mechanisms could elucidate pathways that could be targeted in the future by either behavioral or neuropsychological interventions. A single-blinded randomized controlled trial with an experimental group and an active control group, pretest, posttest, and 6-month follow-up repeated measures design is used in this study. A total of 75 cognitively healthy older adults were randomly distributed into experimental and active control groups. Participants in the experimental group received 16 1-hour training sessions with cognitive nonaction video games selected from Lumosity, a commercial brain training package. The active control group received the same number of training sessions with The Sims and SimCity, a simulation strategy game. We have recruited participants, have conducted the training protocol and pretest assessments, and are

Effectiveness of app-based relaxation for patients with chronic low back pain (Relaxback) and chronic neck pain (Relaxneck): study protocol for two randomized pragmatic trials.

Science.gov (United States)

Blödt, Susanne; Pach, Daniel; Roll, Stephanie; Witt, Claudia M

2014-12-15

Chronic low back pain (LBP) and neck pain (NP) are highly prevalent conditions resulting in high economic costs. Treatment guidelines recommend relaxation techniques, such as progressive muscle relaxation, as adjuvant therapies. Self-care interventions could have the potential to reduce costs in the health care system, but their effectiveness, especially in a usual care setting, is unclear. The aim of these two pragmatic randomized studies is to evaluate whether an additional app-delivered relaxation is more effective in the reduction of chronic LBP or NP than usual care alone. Each pragmatic randomized two-armed study aims to include a total of 220 patients aged 18 to 65 years with chronic (>12 weeks) LBP or NP and an average pain intensity of ≥ 4 on a numeric rating scale (NRS) in the 7 days before recruitment. The participants will be randomized into an intervention and a usual care group. The intervention group will be instructed to practice one of these 3 relaxation techniques on at least 5 days/week for 15 minutes/day over a period of 6 months starting on the day of randomization: autogenic training, mindfulness meditation, or guided imagery. Instructions and exercises will be provided using a smartphone app, baseline information will be collected using paper and pencil. Follow-up information (daily, weekly, and after 3 and 6 months) will be collected using electronic diaries and questionnaires included in the app. The primary outcome measure will be the mean LBP or NP intensity during the first 3 months of intervention based on daily pain intensity measurements on a NRS (0 = no pain, 10 = worst possible pain). The secondary outcome parameters will include the mean pain intensity during the first 6 months after randomization based on daily measurements, the mean pain intensity measured weekly as the average pain intensity of the previous 7 days over 3 and 6 months, pain acceptance, 'LBP- and NP-related' stress, sick leave days, pain medication

Taylor-series and Monte-Carlo-method uncertainty estimation of the width of a probability distribution based on varying bias and random error

International Nuclear Information System (INIS)

Wilson, Brandon M; Smith, Barton L

2013-01-01

Uncertainties are typically assumed to be constant or a linear function of the measured value; however, this is generally not true. Particle image velocimetry (PIV) is one example of a measurement technique that has highly nonlinear, time varying local uncertainties. Traditional uncertainty methods are not adequate for the estimation of the uncertainty of measurement statistics (mean and variance) in the presence of nonlinear, time varying errors. Propagation of instantaneous uncertainty estimates into measured statistics is performed allowing accurate uncertainty quantification of time-mean and statistics of measurements such as PIV. It is shown that random errors will always elevate the measured variance, and thus turbulent statistics such as u'u'-bar. Within this paper, nonlinear, time varying errors are propagated from instantaneous measurements into the measured mean and variance using the Taylor-series method. With these results and knowledge of the systematic and random uncertainty of each measurement, the uncertainty of the time-mean, the variance and covariance can be found. Applicability of the Taylor-series uncertainty equations to time varying systematic and random errors and asymmetric error distributions are demonstrated with Monte-Carlo simulations. The Taylor-series uncertainty estimates are always accurate for uncertainties on the mean quantity. The Taylor-series variance uncertainty is similar to the Monte-Carlo results for cases in which asymmetric random errors exist or the magnitude of the instantaneous variations in the random and systematic errors is near the ‘true’ variance. However, the Taylor-series method overpredicts the uncertainty in the variance as the instantaneous variations of systematic errors are large or are on the same order of magnitude as the ‘true’ variance. (paper)

Classification of high resolution remote sensing image based on geo-ontology and conditional random fields

Science.gov (United States)

Hong, Liang

2013-10-01

The availability of high spatial resolution remote sensing data provides new opportunities for urban land-cover classification. More geometric details can be observed in the high resolution remote sensing image, Also Ground objects in the high resolution remote sensing image have displayed rich texture, structure, shape and hierarchical semantic characters. More landscape elements are represented by a small group of pixels. Recently years, the an object-based remote sensing analysis methodology is widely accepted and applied in high resolution remote sensing image processing. The classification method based on Geo-ontology and conditional random fields is presented in this paper. The proposed method is made up of four blocks: (1) the hierarchical ground objects semantic framework is constructed based on geoontology; (2) segmentation by mean-shift algorithm, which image objects are generated. And the mean-shift method is to get boundary preserved and spectrally homogeneous over-segmentation regions ;(3) the relations between the hierarchical ground objects semantic and over-segmentation regions are defined based on conditional random fields framework ;(4) the hierarchical classification results are obtained based on geo-ontology and conditional random fields. Finally, high-resolution remote sensed image data -GeoEye, is used to testify the performance of the presented method. And the experimental results have shown the superiority of this method to the eCognition method both on the effectively and accuracy, which implies it is suitable for the classification of high resolution remote sensing image.

Light-reflection random-target method for measurement of the modulation transfer function of a digital video-camera

Czech Academy of Sciences Publication Activity Database

Pospíšil, Jaroslav; Jakubík, P.; Machala, L.

2005-01-01

Roč. 116, - (2005), s. 573-585 ISSN 0030-4026 Institutional research plan: CEZ:AV0Z10100522 Keywords : random-target measuring method * light-reflection white - noise target * digital video camera * modulation transfer function * power spectral density Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.395, year: 2005

Social support and education groups for single mothers: a randomized controlled trial of a community-based program.

Science.gov (United States)

Lipman, Ellen L; Boyle, Michael H

2005-12-06

Members of families headed by single mothers are at increased risk of psychosocial disadvantage and mental health problems. We assessed the effect of a community-based program of social support and education groups for single mothers of young children on maternal well-being and parenting. We recruited 116 single mothers of children 3 to 9 years old through community advertisements. Eligible mothers were randomly assigned either to participate in a 10-week program of group sessions (1.5 hours per week) offering social support and education, with a parallel children's activity group, or to receive a standard list of community resources and the option to participate in group sessions at the end of the follow-up period. Interviewers blinded to the randomization collected assessment data from all mothers at baseline and at 3 follow-up visits (immediately after the intervention and at 3 and 6 months after the intervention). Outcome measures were self-reported mood, self-esteem, social support and parenting. Between February 2000 and April 2003, the program was offered to 9 groups of single mothers. Most of the mothers in the trial reported high levels of financial and mental health problems. In the short term (after the intervention), mothers in the intervention group had improved scores for mood (p effect = 0.55) and self-esteem (p effect = 0.29) compared with mothers in the control group; scores for the other 2 measures did not differ between the groups. Growth curve analysis of program effects over the follow-up period showed improvement in all 4 outcomes, with no significant difference between the intervention and control groups. This community-based program of group sessions offering social support and education to low-income single mothers had positive short-term effects on mood and self-esteem but not on social support and parenting. Longer follow-up showed attenuation of these effects.

The impact of a daily smartphone-based feedback system among women with gestational diabetes on compliance, glycemic control, satisfaction, and pregnancy outcome: a randomized controlled trial.

Science.gov (United States)

Miremberg, Hadas; Ben-Ari, Tal; Betzer, Tal; Raphaeli, Hagit; Gasnier, Rose; Barda, Giulia; Bar, Jacob; Weiner, Eran

2018-04-01

Patient compliance and tight glycemic control have been demonstrated to improve outcome in pregnancies complicated by gestational diabetes mellitus. The use of advanced technological tools, including smartphone-based platforms, to improve medical care and outcomes has been demonstrated in various fields of medicine, but only a few small studies were performed with gestational diabetes mellitus patients. We aimed to study the impact of introducing a smartphone-based daily feedback and communication platform between gestational diabetes mellitus patients and their physicians, on patient compliance, glycemic control, pregnancy outcome, and patient satisfaction. This is a prospective, single-center, randomized controlled trial. Newly diagnosed gestational diabetes mellitus patients presenting to our multidisciplinary diabetes-in-pregnancy clinic were randomized to: (1) routine biweekly prenatal clinic care (control group); or (2) additional daily detailed feedback on their compliance and glycemic control from the clinic team via an application installed on their smartphone (smartphone group). The primary outcome was patient compliance defined as the actual blood glucose measurements/instructed measurements ×100. The secondary outcomes included diabetes-control parameters, pregnancy, and neonatal outcomes. The study was adequately powered to detect a 20% difference in patient compliance, based on a preliminary phase that demonstrated 70% baseline compliance to glucose measurements. A total of 120 newly diagnosed gestational diabetes mellitus patients were analyzed. The 2 groups did not differ in terms of age, parity, education, body mass index, family history, maternal comorbidities, oral glucose tolerance test values, and hemoglobin A1C at randomization. The smartphone group demonstrated higher level of compliance (84 ± 0.16% vs 66 ± 0.28%, P diabetes mellitus patients and the multidisciplinary diabetes-in-pregnancy clinic team improved patient compliance and

Performance of medical residents in sterile techniques during central vein catheterization: randomized trial of efficacy of simulation-based training.

Science.gov (United States)

Khouli, Hassan; Jahnes, Katherine; Shapiro, Janet; Rose, Keith; Mathew, Joseph; Gohil, Amit; Han, Qifa; Sotelo, Andre; Jones, James; Aqeel, Adnan; Eden, Edward; Fried, Ethan

2011-01-01

Catheter-related bloodstream infection (CRBSI) is a preventable cause of a potentially lethal ICU infection. The optimal method to teach health-care providers correct sterile techniques during central vein catheterization (CVC) remains unclear. We randomly assigned second- and third-year internal medicine residents trained by a traditional apprenticeship model to simulation-based plus video training or video training alone from December 2007 to January 2008, with a follow-up period to examine CRBSI ending in July 2009. During the follow-up period, a simulation-based training program in sterile techniques during CVC was implemented in the medical ICU (MICU). A surgical ICU (SICU) where no residents received study interventions was used for comparison. The primary outcome measures were median residents' scores in sterile techniques and rates of CRBSI per 1,000 catheter-days. Of the 47 enrolled residents, 24 were randomly assigned to the simulation-based plus video training group and 23 to the video training group. Median baseline scores in both groups were equally poor: 12.5 to 13 (52%-54%) out of maximum score of 24 (P = .95; median difference, 0; 95% CI, 0.2-2.0). After training, median score was significantly higher for the simulation-based plus video training group: 22 (92%) vs 18 (75%) for the video training group (P training in sterile techniques during CVC is superior to traditional training or video training alone and is associated with decreased rate of CRBSI. Simulation-based training in CVC should be routinely used to reduce iatrogenic risk. ClinicalTrials.gov; No.: NCT00612131; URL: clinicaltrials.gov.

Optimal random perturbations for stochastic approximation using a simultaneous perturbation gradient approximation

DEFF Research Database (Denmark)

Sadegh, Payman; Spall, J. C.

1998-01-01

simultaneous perturbation approximation to the gradient based on loss function measurements. SPSA is based on picking a simultaneous perturbation (random) vector in a Monte Carlo fashion as part of generating the approximation to the gradient. This paper derives the optimal distribution for the Monte Carlo...

Web-Based and Mobile Stress Management Intervention for Employees: A Randomized Controlled Trial

OpenAIRE

Heber, Elena; Lehr, Dirk; Ebert, David Daniel; Berking, Matthias; Riper, Heleen

2016-01-01

Background: Work-related stress is highly prevalent among employees and is associated with adverse mental health consequences. Web-based interventions offer the opportunity to deliver effective solutions on a large scale; however, the evidence is limited and the results conflicting. Objective: This randomized controlled trial evaluated the efficacy of guided Web-and mobile-based stress management training for employees. Methods: A total of 264 employees with elevated symptoms of stress (Perce...

Performance of Web-based image distribution: client-oriented measurements

International Nuclear Information System (INIS)

Bergh, B.; Pietsch, M.; Schlaefke, A.; Vogl, T.J.

2003-01-01

The aim of this study was to define a clinically suitable personal computer (PC) configuration for Web-based image distribution and to assess the influence of different hard- and software configurations on the performance. Through specially developed software the time-to-display (TTD) for various PC configurations was measured. Different processor speeds, random access memory (RAM), screen resolutions, graphic adapters, network speeds, operating systems and examination types (computed radiography, CT, MRI) were evaluated, providing more than half a million measurements. Processor speed was the most relevant factor for the TTD; doubling the speed halved the TTD. Under processor speeds of 350 MHz, TTD mostly remained above 5 s for 1 CR or 16 CT images. Here Windows NT with lossy compression were superior. Processor speeds of 350 MHz and over delivered TTD <5 s. In this case Windows 2000 and lossless compression were preferable. Screen resolutions above 1280 x 1024 pixels increased the TTD mainly for CR images. The RAM amount, network speed and graphic adapter did not have a significant influence. The minimum threshold for clinical routine is any standard off-the-shelf PC better than Pentium II 350 MHz, 128 MB RAM; hence, high-end PC hardware is not required. (orig.)

Comparison of group-based outpatient physiotherapy with usual care after total knee replacement: a feasibility study for a randomized controlled trial.

Science.gov (United States)

Artz, Neil; Dixon, Samantha; Wylde, Vikki; Marques, Elsa; Beswick, Andrew D; Lenguerrand, Erik; Blom, Ashley W; Gooberman-Hill, Rachael

2017-04-01

To evaluate the feasibility of conducting a randomized controlled trial comparing group-based outpatient physiotherapy with usual care in patients following total knee replacement. A feasibility study for a randomized controlled trial. One secondary-care hospital orthopaedic centre, Bristol, UK. A total of 46 participants undergoing primary total knee replacement. The intervention group were offered six group-based exercise sessions after surgery. The usual care group received standard postoperative care. Participants were not blinded to group allocation. Feasibility was assessed by recruitment, reasons for non-participation, attendance, and completion rates of study questionnaires that included the Lower Extremity Functional Scale and Knee Injury and Osteoarthritis Outcome Score. Recruitment rate was 37%. Five patients withdrew or were no longer eligible to participate. Intervention attendance was high (73%) and 84% of group participants reported they were 'very satisfied' with the exercises. Return of study questionnaires at six months was lower in the usual care (75%) than in the intervention group (100%). Mean (standard deviation) Lower Extremity Functional Scale scores at six months were 45.0 (20.8) in the usual care and 57.8 (15.2) in the intervention groups. Recruitment and retention of participants in this feasibility study was good. Group-based physiotherapy was acceptable to participants. Questionnaire return rates were lower in the usual care group, but might be enhanced by telephone follow-up. The Lower Extremity Functional Scale had high responsiveness and completion rates. Using this outcome measure, 256 participants would be required in a full-scale randomized controlled trial.

A matched pair cluster randomized implementation trail to measure the effectiveness of an intervention package aiming to decrease perinatal mortality and increase institution-based obstetric care among indigenous women in Guatemala: study protocol.

Science.gov (United States)

Kestler, Edgar; Walker, Dilys; Bonvecchio, Anabelle; de Tejada, Sandra Sáenz; Donner, Allan

2013-03-21

Maternal and perinatal mortality continue to be a high priority problem on the health agendas of less developed countries. Despite the progress made in the last decade to quantify the magnitude of maternal mortality, few interventions have been implemented with the intent to measure impact directly on maternal or perinatal deaths. The success of interventions implemented in less developed countries to reduce mortality has been questioned, in terms of the tendency to maintain a clinical perspective with a focus on purely medical care separate from community-based approaches that take cultural and social aspects of maternal and perinatal deaths into account. Our innovative approach utilizes both the clinical and community perspectives; moreover, our study will report the weight that each of these components may have had on reducing perinatal mortality and increasing institution-based deliveries. A matched pair cluster-randomized trial will be conducted in clinics in four rural indigenous districts with the highest maternal mortality ratios in Guatemala. The individual clinic will serve as the unit of randomization, with 15 matched pairs of control and intervention clinics composing the final sample. Three interventions will be implemented in indigenous, rural and poor populations: a simulation training program for emergency obstetric and perinatal care, increased participation of the professional midwife in strengthening the link between traditional birth attendants (TBA) and the formal health care system, and a social marketing campaign to promote institution-based deliveries. No external intervention is planned for control clinics, although enhanced monitoring, surveillance and data collection will occur throughout the study in all clinics throughout the four districts. All obstetric events occurring in any of the participating health facilities and districts during the 18 months implementation period will be included in the analysis, controlling for the cluster

Randomized clinical trial of Appendicitis Inflammatory Response score-based management of patients with suspected appendicitis.

Science.gov (United States)

Andersson, M; Kolodziej, B; Andersson, R E

2017-10-01

The role of imaging in the diagnosis of appendicitis is controversial. This prospective interventional study and nested randomized trial analysed the impact of implementing a risk stratification algorithm based on the Appendicitis Inflammatory Response (AIR) score, and compared routine imaging with selective imaging after clinical reassessment. Patients presenting with suspicion of appendicitis between September 2009 and January 2012 from age 10 years were included at 21 emergency surgical centres and from age 5 years at three university paediatric centres. Registration of clinical characteristics, treatments and outcomes started during the baseline period. The AIR score-based algorithm was implemented during the intervention period. Intermediate-risk patients were randomized to routine imaging or selective imaging after clinical reassessment. The baseline period included 1152 patients, and the intervention period 2639, of whom 1068 intermediate-risk patients were randomized. In low-risk patients, use of the AIR score-based algorithm resulted in less imaging (19·2 versus 34·5 per cent; P appendicitis (6·8 versus 9·7 per cent; P = 0·034). Intermediate-risk patients randomized to the imaging and observation groups had the same proportion of negative appendicectomies (6·4 versus 6·7 per cent respectively; P = 0·884), number of admissions, number of perforations and length of hospital stay, but routine imaging was associated with an increased proportion of patients treated for appendicitis (53·4 versus 46·3 per cent; P = 0·020). AIR score-based risk classification can safely reduce the use of diagnostic imaging and hospital admissions in patients with suspicion of appendicitis. Registration number: NCT00971438 ( http://www.clinicaltrials.gov). © 2017 BJS Society Ltd Published by John Wiley & Sons Ltd.

Measuring and testing dependence by correlation of distances

OpenAIRE

Székely, Gábor J.; Rizzo, Maria L.; Bakirov, Nail K.

2007-01-01

Distance correlation is a new measure of dependence between random vectors. Distance covariance and distance correlation are analogous to product-moment covariance and correlation, but unlike the classical definition of correlation, distance correlation is zero only if the random vectors are independent. The empirical distance dependence measures are based on certain Euclidean distances between sample elements rather than sample moments, yet have a compact representation analogous to the clas...

Global industrial impact coefficient based on random walk process and inter-country input-output table

Science.gov (United States)

Xing, Lizhi; Dong, Xianlei; Guan, Jun

2017-04-01

Input-output table is very comprehensive and detailed in describing the national economic system with lots of economic relationships, which contains supply and demand information among industrial sectors. The complex network, a theory and method for measuring the structure of complex system, can describe the structural characteristics of the internal structure of the research object by measuring the structural indicators of the social and economic system, revealing the complex relationship between the inner hierarchy and the external economic function. This paper builds up GIVCN-WIOT models based on World Input-Output Database in order to depict the topological structure of Global Value Chain (GVC), and assumes the competitive advantage of nations is equal to the overall performance of its domestic sectors' impact on the GVC. Under the perspective of econophysics, Global Industrial Impact Coefficient (GIIC) is proposed to measure the national competitiveness in gaining information superiority and intermediate interests. Analysis of GIVCN-WIOT models yields several insights including the following: (1) sectors with higher Random Walk Centrality contribute more to transmitting value streams within the global economic system; (2) Half-Value Ratio can be used to measure robustness of open-economy macroeconomics in the process of globalization; (3) the positive correlation between GIIC and GDP indicates that one country's global industrial impact could reveal its international competitive advantage.

Feasibility of scenario-based simulation training versus traditional workshops in continuing medical education: a randomized controlled trial

Directory of Open Access Journals (Sweden)

Brendan Kerr

2013-07-01

Full Text Available Introduction: Although simulation-based training is increasingly used for medical education, its benefits in continuing medical education (CME are less established. This study seeks to evaluate the feasibility of incorporating simulation-based training into a CME conference and compare its effectiveness with the traditional workshop in improving knowledge and self-reported confidence. Methods: Participants (N=27 were group randomized to either a simulation-based workshop or a traditional case-based workshop. Results: Post-training, knowledge assessment score neither did increase significantly in the traditional group (d=0.13; p=0.76 nor did significantly decrease in the simulation group (d= − 0.44; p=0.19. Self-reported comfort in patient assessment parameters increased in both groups (p<0.05 in all. However, only the simulation group reported an increase in comfort in patient management (d=1.1, p=0.051 for the traditional group and d=1.3; p= 0.0003 for the simulation group. At 1 month, comfort measures in the traditional group increased consistently over time while these measures in the simulation group increased post-workshop but decreased by 1 month, suggesting that some of the effects of training with simulation may be short lived. Discussion: The use of simulation-based training was not associated with benefits in knowledge acquisition, knowledge retention, or comfort in patient assessment. It was associated with superior outcomes in comfort in patient management, but this benefit may be short-lived. Further studies are required to better define the conditions under which simulation-based training is beneficial.

Efficacy of the Ubiquitous Spaced Retrieval-based Memory Advancement and Rehabilitation Training (USMART) program among patients with mild cognitive impairment: a randomized controlled crossover trial.

Science.gov (United States)

Han, Ji Won; Son, Kyung Lak; Byun, Hye Jin; Ko, Ji Won; Kim, Kayoung; Hong, Jong Woo; Kim, Tae Hyun; Kim, Ki Woong

2017-06-06

Spaced retrieval training (SRT) is a nonpharmacological intervention for mild cognitive impairment (MCI) and dementia that trains the learning and retention of target information by recalling it over increasingly long intervals. We recently developed the Ubiquitous Spaced Retrieval-based Memory Advancement and Rehabilitation Training (USMART) program as a convenient, self-administered tablet-based SRT program. We also demonstrated the utility of USMART for improving memory in individuals with MCI through an open-label uncontrolled trial. This study had an open-label, single-blind, randomized, controlled, two-period crossover design. Fifty patients with MCI were randomized into USMART-usual care and usual care-USMART treatment sequences. USMART was completed or usual care was provided biweekly over a 4-week treatment period with a 2-week washout period between treatment periods. Primary outcome measures included the Word List Memory Test, Word List Recall Test (WLRT), and Word List Recognition Test. Outcomes were measured at baseline, week 5, and week 11 by raters who were blinded to intervention type. An intention-to-treat analysis and linear mixed modeling were used. Of 50 randomized participants, 41 completed the study (18% dropout rate). The USMART group had larger improvements in WLRT score (effect size = 0.49, p = 0.031) than the usual care group. There were no significant differences in other primary or secondary measures between the USMART and usual care groups. Moreover, no USMART-related adverse events were reported. The 4-week USMART modestly improved information retrieval in older people with MCI, and was well accepted with minimal technical support. ClinicalTrials.gov NCT01688128 . Registered 12 September 2012.

Hyperspectral band selection based on consistency-measure of neighborhood rough set theory

International Nuclear Information System (INIS)

Liu, Yao; Xie, Hong; Wang, Liguo; Tan, Kezhu; Chen, Yuehua; Xu, Zhen

2016-01-01

Band selection is a well-known approach for reducing dimensionality in hyperspectral imaging. In this paper, a band selection method based on consistency-measure of neighborhood rough set theory (CMNRS) was proposed to select informative bands from hyperspectral images. A decision-making information system was established by the reflection spectrum of soybeans’ hyperspectral data between 400 nm and 1000 nm wavelengths. The neighborhood consistency-measure, which reflects not only the size of the decision positive region, but also the sample distribution in the boundary region, was used as the evaluation function of band significance. The optimal band subset was selected by a forward greedy search algorithm. A post-pruning strategy was employed to overcome the over-fitting problem and find the minimum subset. To assess the effectiveness of the proposed band selection technique, two classification models (extreme learning machine (ELM) and random forests (RF)) were built. The experimental results showed that the proposed algorithm can effectively select key bands and obtain satisfactory classification accuracy. (paper)

Dynamic Output Feedback Control for Nonlinear Networked Control Systems with Random Packet Dropout and Random Delay

Directory of Open Access Journals (Sweden)

Shuiqing Yu

2013-01-01

Full Text Available This paper investigates the dynamic output feedback control for nonlinear networked control systems with both random packet dropout and random delay. Random packet dropout and random delay are modeled as two independent random variables. An observer-based dynamic output feedback controller is designed based upon the Lyapunov theory. The quantitative relationship of the dropout rate, transition probability matrix, and nonlinear level is derived by solving a set of linear matrix inequalities. Finally, an example is presented to illustrate the effectiveness of the proposed method.

Interactive Voice Response-Based Self-management for Chronic Back Pain: The COPES Noninferiority Randomized Trial.

Science.gov (United States)

Heapy, Alicia A; Higgins, Diana M; Goulet, Joseph L; LaChappelle, Kathryn M; Driscoll, Mary A; Czlapinski, Rebecca A; Buta, Eugenia; Piette, John D; Krein, Sarah L; Kerns, Robert D

2017-06-01

Recommendations for chronic pain treatment emphasize multimodal approaches, including nonpharmacologic interventions to enhance self-management. Cognitive behavioral therapy (CBT) is an evidence-based treatment that facilitates management of chronic pain and improves outcomes, but access barriers persist. Cognitive behavioral therapy delivery assisted by health technology can obviate the need for in-person visits, but the effectiveness of this alternative to standard therapy is unknown. The Cooperative Pain Education and Self-management (COPES) trial was a randomized, noninferiority trial comparing IVR-CBT to in-person CBT for patients with chronic back pain. To assess the efficacy of interactive voice response-based CBT (IVR-CBT) relative to in-person CBT for chronic back pain. We conducted a noninferiority randomized trial in 1 Department of Veterans Affairs (VA) health care system. A total of 125 patients with chronic back pain were equally allocated to IVR-CBT (n = 62) or in-person CBT (n = 63). Patients treated with IVR-CBT received a self-help manual and weekly prerecorded therapist feedback based on their IVR-reported activity, coping skill practice, and pain outcomes. In-person CBT included weekly, individual CBT sessions with a therapist. Participants in both conditions received IVR monitoring of pain, sleep, activity levels, and pain coping skill practice during treatment. The primary outcome was change from baseline to 3 months in unblinded patient report of average pain intensity measured by the Numeric Rating Scale (NRS). Secondary outcomes included changes in pain-related interference, physical and emotional functioning, sleep quality, and quality of life at 3, 6, and 9 months. We also examined treatment retention. Of the 125 patients (97 men, 28 women; mean [SD] age, 57.9 [11.6] years), the adjusted average reduction in NRS with IVR-CBT (-0.77) was similar to in-person CBT (-0.84), with the 95% CI for the difference between groups (-0.67 to 0

Some Limits Using Random Slope Models to Measure Academic Growth

Directory of Open Access Journals (Sweden)

Daniel B. Wright

2017-11-01

Full Text Available Academic growth is often estimated using a random slope multilevel model with several years of data. However, if there are few time points, the estimates can be unreliable. While using random slope multilevel models can lower the variance of the estimates, these procedures can produce more highly erroneous estimates—zero and negative correlations with the true underlying growth—than using ordinary least squares estimates calculated for each student or school individually. An example is provided where schools with increasing graduation rates are estimated to have negative growth and vice versa. The estimation is worse when the underlying data are skewed. It is recommended that there are at least six time points for estimating growth if using a random slope model. A combination of methods can be used to avoid some of the aberrant results if it is not possible to have six or more time points.

Assessing the Effectiveness of Case-Based Collaborative Learning via Randomized Controlled Trial.

Science.gov (United States)

Krupat, Edward; Richards, Jeremy B; Sullivan, Amy M; Fleenor, Thomas J; Schwartzstein, Richard M

2016-05-01

Case-based collaborative learning (CBCL) is a novel small-group approach that borrows from team-based learning principles and incorporates elements of problem-based learning (PBL) and case-based learning. CBCL includes a preclass readiness assurance process and case-based in-class activities in which students respond to focused, open-ended questions individually, discuss their answers in groups of 4, and then reach consensus in larger groups of 16. This study introduces CBCL and assesses its effectiveness in one course at Harvard Medical School. In a 2013 randomized controlled trial, 64 medical and dental student volunteers were assigned randomly to one of four 8-person PBL tutorial groups (control; n = 32) or one of two 16-person CBCL tutorial groups (experimental condition; n = 32) as part of a required first-year physiology course. Outcomes for the PBL and CBCL groups were compared using final exam scores, student responses to a postcourse survey, and behavioral coding of portions of video-recorded class sessions. Overall, the course final exam scores for CBCL and PBL students were not significantly different. However, CBCL students whose mean exam performance in prior courses was below the participant median scored significantly higher than their PBL counterparts on the physiology course final exam. The most common adjectives students used to describe CBCL were "engaging," "fun," and "thought-provoking." Coding of observed behaviors indicated that individual affect was significantly higher in the CBCL groups than in the PBL groups. CBCL is a viable, engaging, active learning method. It may particularly benefit students with lower academic performance.

Web-Based Decision Aid to Assist Help-Seeking Choices for Young People Who Self-Harm: Outcomes From a Randomized Controlled Feasibility Trial

Science.gov (United States)

Patel, Krisna; French, Rebecca S; Henderson, Claire; Ougrin, Dennis; Slade, Mike; Moran, Paul

2018-01-01

Background Adolescents who self-harm are often unsure how or where to get help. We developed a Web-based personalized decision aid (DA) designed to support young people in decision making about seeking help for their self-harm. Objective The aim of this study was to evaluate the feasibility and acceptability of the DA intervention and the randomized controlled trial (RCT) in a school setting. Methods We conducted a two-group, single blind, randomized controlled feasibility trial in a school setting. Participants aged 12 to 18 years who reported self-harm in the past 12 months were randomized to either a Web-based DA or to general information about mood and feelings. Feasibility of recruitment, randomization, and follow-up rates were assessed, as was acceptability of the intervention and study procedures. Descriptive data were collected on outcome measures examining decision making and help-seeking behavior. Qualitative interviews were conducted with young people, parents or carers, and staff and subjected to thematic analysis to explore their views of the DA and study processes. Results Parental consent was a significant barrier to young people participating in the trial, with only 17.87% (208/1164) of parents or guardians who were contacted for consent responding to study invitations. Where parental consent was obtained, we were able to recruit 81.7% (170/208) of young people into the study. Of those young people screened, 13.5% (23/170) had self-harmed in the past year. Ten participants were randomized to receiving the DA, and 13 were randomized to the control group. Four-week follow-up assessments were completed with all participants. The DA had good acceptability, but qualitative interviews suggested that a DA that addressed broader mental health problems such as depression, anxiety, and self-harm may be more beneficial. Conclusions A broad-based mental health DA addressing a wide range of psychosocial problems may be useful for young people. The requirement

A random walk model for evaluating clinical trials involving serial observations.

Science.gov (United States)

Hopper, J L; Young, G P

1988-05-01

For clinical trials where the variable of interest is ordered and categorical (for example, disease severity, symptom scale), and where measurements are taken at intervals, it might be possible to achieve a greater discrimination between the efficacy of treatments by modelling each patient's progress as a stochastic process. The random walk is a simple, easily interpreted model that can be fitted by maximum likelihood using a maximization routine with inference based on standard likelihood theory. In general the model can allow for randomly censored data, incorporates measured prognostic factors, and inference is conditional on the (possibly non-random) allocation of patients. Tests of fit and of model assumptions are proposed, and application to two therapeutic trials of gastroenterological disorders are presented. The model gave measures of the rate of, and variability in, improvement for patients under different treatments. A small simulation study suggested that the model is more powerful than considering the difference between initial and final scores, even when applied to data generated by a mechanism other than the random walk model assumed in the analysis. It thus provides a useful additional statistical method for evaluating clinical trials.

Automatic Recognition of Chinese Personal Name Using Conditional Random Fields and Knowledge Base

Directory of Open Access Journals (Sweden)

Chuan Gu

2015-01-01

Full Text Available According to the features of Chinese personal name, we present an approach for Chinese personal name recognition based on conditional random fields (CRF and knowledge base in this paper. The method builds multiple features of CRF model by adopting Chinese character as processing unit, selects useful features based on selection algorithm of knowledge base and incremental feature template, and finally implements the automatic recognition of Chinese personal name from Chinese document. The experimental results on open real corpus demonstrated the effectiveness of our method and obtained high accuracy rate and high recall rate of recognition.

Refractive index based measurements

DEFF Research Database (Denmark)

2014-01-01

In a method for performing a refractive index based measurement of a property of a fluid such as chemical composition or temperature by observing an apparent angular shift in an interference fringe pattern produced by back or forward scattering interferometry, ambiguities in the measurement caused...... by the apparent shift being consistent with one of a number of numerical possibilities for the real shift which differ by 2n are resolved by combining measurements performed on the same sample using light paths therethrough of differing lengths....

Web-based alcohol screening and brief intervention for university students: a randomized trial.

Science.gov (United States)

Kypri, Kypros; Vater, Tina; Bowe, Steven J; Saunders, John B; Cunningham, John A; Horton, Nicholas J; McCambridge, Jim

2014-03-26

Unhealthy alcohol use is a leading contributor to the global burden of disease, particularly among young people. Systematic reviews suggest efficacy of web-based alcohol screening and brief intervention and call for effectiveness trials in settings where it could be sustainably delivered. To evaluate a national web-based alcohol screening and brief intervention program. A multisite, double-blind, parallel-group, individually randomized trial was conducted at 7 New Zealand universities. In April and May of 2010, invitations containing hyperlinks to the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) screening test were e-mailed to 14,991 students aged 17 to 24 years. Participants who screened positive (AUDIT-C score ≥4) were randomized to undergo screening alone or to 10 minutes of assessment and feedback (including comparisons with medical guidelines and peer norms) on alcohol expenditure, peak blood alcohol concentration, alcohol dependence, and access to help and information. A fully automated 5-month follow-up assessment was conducted that measured 6 primary outcomes: consumption per typical occasion, drinking frequency, volume of alcohol consumed, an academic problems score, and whether participants exceeded medical guidelines for acute harm (binge drinking) and chronic harm (heavy drinking). A Bonferroni-corrected significance threshold of .0083 was used to account for the 6 comparisons and a sensitivity analysis was used to assess possible attrition bias. Of 5135 students screened, 3422 scored 4 or greater and were randomized, and 83% were followed up. There was a significant effect on 1 of the 6 prespecified outcomes. Relative to control participants, those who received intervention consumed less alcohol per typical drinking occasion (median 4 drinks [interquartile range {IQR}, 2-8] vs 5 drinks [IQR 2-8]; rate ratio [RR], 0.93 [99.17% CI, 0.86-1.00]; P = .005) but not less often (RR, 0.95 [99.17% CI, 0.88-1.03]; P = .08) or less

A cluster randomized controlled trial testing the effectiveness of Houvast: A strengths-based intervention for homeless young adults

NARCIS (Netherlands)

Krabbenborg, M.A.M.; Boersma, S.N.; Veld, W.M. van der; Hulst, B. van; Vollebergh, W.A.M.; Wolf, J.R.L.M.

2017-01-01

Objective: To test the effectiveness of Houvast: a strengths-based intervention for homeless young adults. Method: A cluster randomized controlled trial was conducted with 10 Dutch shelter facilities randomly allocated to an intervention and a control group. Homeless young adults were interviewed

Rationale and design of a randomized controlled trial examining the effect of classroom-based physical activity on math achievement.

Science.gov (United States)

Have, Mona; Nielsen, Jacob Have; Gejl, Anne Kær; Thomsen Ernst, Martin; Fredens, Kjeld; Støckel, Jan Toftegaard; Wedderkopp, Niels; Domazet, Sidsel Louise; Gudex, Claire; Grøntved, Anders; Kristensen, Peter Lund

2016-04-11

Integration of physical activity (PA) into the classroom may be an effective way of promoting the learning and academic achievement of children at elementary school. This paper describes the research design and methodology of an intervention study examining the effect of classroom-based PA on mathematical achievement, creativity, executive function, body mass index and aerobic fitness. The study was designed as a school-based cluster-randomized controlled trial targeting schoolchildren in 1st grade, and was carried out between August 2012 and June 2013. Eligible schools in two municipalities in the Region of Southern Denmark were invited to participate in the study. After stratification by municipality, twelve schools were randomized to either an intervention group or a control group, comprising a total of 505 children with mean age 7.2 ± 0.3 years. The intervention was a 9-month classroom-based PA program that involved integration of PA into the math lessons delivered by the schools' math teachers. The primary study outcome was change in math achievement, measured by a 45-minute standardized math test. Secondary outcomes were change in executive function (using a modified Eriksen flanker task and the Behavior Rating Inventory of Executive Function (BRIEF) questionnaire filled out by the parents), creativity (using the Torrance Tests of Creative Thinking, TTCT), aerobic fitness (by the Andersen intermittent shuttle-run test) and body mass index. PA during math lessons and total PA (including time spent outside school) were assessed using accelerometry. Math teachers used Short Message Service (SMS)-tracking to report on compliance with the PA intervention and on their motivation for implementing PA in math lessons. Parents used SMS-tracking to register their children's PA behavior in leisure time. The results of this randomized controlled trial are expected to provide schools and policy-makers with significant new insights into the potential of classroom-based

Rationale and design of a randomized controlled trial examining the effect of classroom-based physical activity on math achievement

Directory of Open Access Journals (Sweden)

Mona Have

2016-04-01

Full Text Available Abstract Background Integration of physical activity (PA into the classroom may be an effective way of promoting the learning and academic achievement of children at elementary school. This paper describes the research design and methodology of an intervention study examining the effect of classroom-based PA on mathematical achievement, creativity, executive function, body mass index and aerobic fitness. Methods The study was designed as a school-based cluster-randomized controlled trial targeting schoolchildren in 1st grade, and was carried out between August 2012 and June 2013. Eligible schools in two municipalities in the Region of Southern Denmark were invited to participate in the study. After stratification by municipality, twelve schools were randomized to either an intervention group or a control group, comprising a total of 505 children with mean age 7.2 ± 0.3 years. The intervention was a 9-month classroom-based PA program that involved integration of PA into the math lessons delivered by the schools’ math teachers. The primary study outcome was change in math achievement, measured by a 45-minute standardized math test. Secondary outcomes were change in executive function (using a modified Eriksen flanker task and the Behavior Rating Inventory of Executive Function (BRIEF questionnaire filled out by the parents, creativity (using the Torrance Tests of Creative Thinking, TTCT, aerobic fitness (by the Andersen intermittent shuttle-run test and body mass index. PA during math lessons and total PA (including time spent outside school were assessed using accelerometry. Math teachers used Short Message Service (SMS-tracking to report on compliance with the PA intervention and on their motivation for implementing PA in math lessons. Parents used SMS-tracking to register their children’s PA behavior in leisure time. Discussion The results of this randomized controlled trial are expected to provide schools and policy-makers with

Misuse of randomization

DEFF Research Database (Denmark)

Liu, Jianping; Kjaergard, Lise Lotte; Gluud, Christian

2002-01-01

The quality of randomization of Chinese randomized trials on herbal medicines for hepatitis B was assessed. Search strategy and inclusion criteria were based on the published protocol. One hundred and seventy-six randomized clinical trials (RCTs) involving 20,452 patients with chronic hepatitis B...... virus (HBV) infection were identified that tested Chinese medicinal herbs. They were published in 49 Chinese journals. Only 10% (18/176) of the studies reported the method by which they randomized patients. Only two reported allocation concealment and were considered as adequate. Twenty percent (30...

Assessing Therapist Competence: Development of a Performance-Based Measure and Its Comparison With a Web-Based Measure.

Science.gov (United States)

Cooper, Zafra; Doll, Helen; Bailey-Straebler, Suzanne; Bohn, Kristin; de Vries, Dian; Murphy, Rebecca; O'Connor, Marianne E; Fairburn, Christopher G

2017-10-31

Recent research interest in how best to train therapists to deliver psychological treatments has highlighted the need for rigorous, but scalable, means of measuring therapist competence. There are at least two components involved in assessing therapist competence: the assessment of their knowledge of the treatment concerned, including how and when to use its strategies and procedures, and an evaluation of their ability to apply such knowledge skillfully in practice. While the assessment of therapists' knowledge has the potential to be completed efficiently on the Web, the assessment of skill has generally involved a labor-intensive process carried out by clinicians, and as such, may not be suitable for assessing training outcome in certain circumstances. The aims of this study were to develop and evaluate a role-play-based measure of skill suitable for assessing training outcome and to compare its performance with a highly scalable Web-based measure of applied knowledge. Using enhanced cognitive behavioral therapy (CBT-E) for eating disorders as an exemplar, clinical scenarios for role-play assessment were developed and piloted together with a rating scheme for assessing trainee therapists' performance. These scenarios were evaluated by examining the performance of 93 therapists from different professional backgrounds and at different levels of training in implementing CBT-E. These therapists also completed a previously developed Web-based measure of applied knowledge, and the ability of the Web-based measure to efficiently predict competence on the role-play measure was investigated. The role-play measure assessed performance at implementing a range of CBT-E procedures. The majority of the therapists rated their performance as moderately or closely resembling their usual clinical performance. Trained raters were able to achieve good-to-excellent reliability for averaged competence, with intraclass correlation coefficients ranging from .653 to 909. The measure was

Rényi Entropies from Random Quenches in Atomic Hubbard and Spin Models

Science.gov (United States)

Elben, A.; Vermersch, B.; Dalmonte, M.; Cirac, J. I.; Zoller, P.

2018-02-01

We present a scheme for measuring Rényi entropies in generic atomic Hubbard and spin models using single copies of a quantum state and for partitions in arbitrary spatial dimensions. Our approach is based on the generation of random unitaries from random quenches, implemented using engineered time-dependent disorder potentials, and standard projective measurements, as realized by quantum gas microscopes. By analyzing the properties of the generated unitaries and the role of statistical errors, with respect to the size of the partition, we show that the protocol can be realized in existing quantum simulators and used to measure, for instance, area law scaling of entanglement in two-dimensional spin models or the entanglement growth in many-body localized systems.

Cognitive-Behavioral-Based Physical Therapy for Patients With Chronic Pain Undergoing Lumbar Spine Surgery: A Randomized Controlled Trial.

Science.gov (United States)

Archer, Kristin R; Devin, Clinton J; Vanston, Susan W; Koyama, Tatsuki; Phillips, Sharon E; George, Steven Z; McGirt, Matthew J; Spengler, Dan M; Aaronson, Oran S; Cheng, Joseph S; Wegener, Stephen T

2016-01-01

The purpose of this study was to determine the efficacy of a cognitive-behavioral-based physical therapy (CBPT) program for improving outcomes in patients after lumbar spine surgery. A randomized controlled trial was conducted on 86 adults undergoing a laminectomy with or without arthrodesis for a lumbar degenerative condition. Patients were screened preoperatively for high fear of movement using the Tampa Scale for Kinesiophobia. Randomization to either CBPT or an education program occurred at 6 weeks after surgery. Assessments were completed pretreatment, posttreatment and at 3-month follow-up. The primary outcomes were pain and disability measured by the Brief Pain Inventory and Oswestry Disability Index. Secondary outcomes included general health (SF-12) and performance-based tests (5-Chair Stand, Timed Up and Go, 10-Meter Walk). Multivariable linear regression analyses found that CBPT participants had significantly greater decreases in pain and disability and increases in general health and physical performance compared with the education group at the 3-month follow-up. Results suggest a targeted CBPT program may result in significant and clinically meaningful improvement in postoperative outcomes. CBPT has the potential to be an evidence-based program that clinicians can recommend for patients at risk for poor recovery after spine surgery. This study investigated a targeted cognitive-behavioral-based physical therapy program for patients after lumbar spine surgery. Findings lend support to the hypothesis that incorporating cognitive-behavioral strategies into postoperative physical therapy may address psychosocial risk factors and improve pain, disability, general health, and physical performance outcomes. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

A mindfulness-based intervention to control weight after bariatric surgery: Preliminary results from a randomized controlled pilot trial.

Science.gov (United States)

Chacko, Sara A; Yeh, Gloria Y; Davis, Roger B; Wee, Christina C

2016-10-01

This study aimed to develop and test a novel mindfulness-based intervention (MBI) designed to control weight after bariatric surgery. Randomized, controlled pilot trial. Beth Israel Deaconess Medical Center, Boston, MA, USA. Bariatric patients 1-5 years post-surgery (n=18) were randomized to receive a 10-week MBI or a standard intervention. Primary outcomes were feasibility and acceptability of the MBI. Secondary outcomes included changes in weight, eating behaviors, psychosocial outcomes, and metabolic and inflammatory biomarkers. Qualitative exit interviews were conducted post-intervention. Major themes were coded and extracted. Attendance was excellent (6 of 9 patients attended ≥7 of 10 classes). Patients reported high satisfaction and overall benefit of the MBI. The intervention was effective in reducing emotional eating at 6 months (-4.9±13.7 in mindfulness vs. 6.2±28.4 in standard, p for between-group difference=0.03) but not weight. We also observed a significant increase in HbA1C (0.34±0.38 vs. -0.06±0.31, p=0.03). Objective measures suggested trends of an increase in perceived stress and symptoms of depression, although patients reported reduced stress reactivity, improved eating behaviors, and a desire for continued mindfulness-based support in qualitative interviews. This novel mindfulness-based approach is highly acceptable to bariatric patients post-surgery and may be effective for reducing emotional eating, although it did not improve weight or glycemic control in the short term. Longer-term studies of mindfulness-based approaches may be warranted in this population. ClinicalTrials.gov identifier NCT02603601. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measuring time series regularity using nonlinear similarity-based sample entropy

International Nuclear Information System (INIS)

Xie Hongbo; He Weixing; Liu Hui

2008-01-01

Sampe Entropy (SampEn), a measure quantifying regularity and complexity, is believed to be an effective analyzing method of diverse settings that include both deterministic chaotic and stochastic processes, particularly operative in the analysis of physiological signals that involve relatively small amount of data. However, the similarity definition of vectors is based on Heaviside function, of which the boundary is discontinuous and hard, may cause some problems in the validity and accuracy of SampEn. Sigmoid function is a smoothed and continuous version of Heaviside function. To overcome the problems SampEn encountered, a modified SampEn (mSampEn) based on nonlinear Sigmoid function was proposed. The performance of mSampEn was tested on the independent identically distributed (i.i.d.) uniform random numbers, the MIX stochastic model, the Rossler map, and the Hennon map. The results showed that mSampEn was superior to SampEn in several aspects, including giving entropy definition in case of small parameters, better relative consistency, robust to noise, and more independence on record length when characterizing time series generated from either deterministic or stochastic system with different regularities

Hydrotherapy versus conventional land-based exercise for the management of patients with osteoarthritis of the knee: a randomized clinical trial.

Science.gov (United States)

Silva, Luciana E; Valim, Valeria; Pessanha, Ana Paula C; Oliveira, Leda M; Myamoto, Samira; Jones, Anamaria; Natour, Jamil

2008-01-01

This study was designed to evaluate the effectiveness of hydrotherapy in subjects with osteoarthritis (OA) of the knee compared with subjects with OA of the knee who performed land-based exercises. Sixty-four subjects with OA of the knee were randomly assigned to 1 of 2 groups that performed exercises for 18 weeks: a water-based exercise group and a land-based exercise group. The outcome measures included a visual analog scale (VAS) for pain in the previous week, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), pain during gait assessed by a VAS at rest and immediately following a 50-foot (15.24-m) walk test (50FWT), walking time measured at fast and comfortable paces during the 50FWT, and the Lequesne Index. Measurements were recorded by a blinded investigator at baseline and at 9 and 18 weeks after initiating the intervention. The 2 groups were homogenous regarding all parameters at baseline. Reductions in pain and improvements in WOMAC and Lequesne index scores were similar between groups. Pain before and after the 50FWT decreased significantly over time in both groups. However, the water-based exercise group experienced a significantly greater decrease in pain than the land-based exercise group before and after the 50FWT at the week-18 follow-up. Both water-based and land-based exercises reduced knee pain and increased knee function in participants with OA of the knee. Hydrotherapy was superior to land-based exercise in relieving pain before and after walking during the last follow-up. Water-based exercises are a suitable and effective alternative for the management of OA of the knee.

Inference of median difference based on the Box-Cox model in randomized clinical trials.

Science.gov (United States)

Maruo, K; Isogawa, N; Gosho, M

2015-05-10

In randomized clinical trials, many medical and biological measurements are not normally distributed and are often skewed. The Box-Cox transformation is a powerful procedure for comparing two treatment groups for skewed continuous variables in terms of a statistical test. However, it is difficult to directly estimate and interpret the location difference between the two groups on the original scale of the measurement. We propose a helpful method that infers the difference of the treatment effect on the original scale in a more easily interpretable form. We also provide statistical analysis packages that consistently include an estimate of the treatment effect, covariance adjustments, standard errors, and statistical hypothesis tests. The simulation study that focuses on randomized parallel group clinical trials with two treatment groups indicates that the performance of the proposed method is equivalent to or better than that of the existing non-parametric approaches in terms of the type-I error rate and power. We illustrate our method with cluster of differentiation 4 data in an acquired immune deficiency syndrome clinical trial. Copyright © 2015 John Wiley & Sons, Ltd.

Intelligent Fault Diagnosis of HVCB with Feature Space Optimization-Based Random Forest.

Science.gov (United States)

Ma, Suliang; Chen, Mingxuan; Wu, Jianwen; Wang, Yuhao; Jia, Bowen; Jiang, Yuan

2018-04-16

Mechanical faults of high-voltage circuit breakers (HVCBs) always happen over long-term operation, so extracting the fault features and identifying the fault type have become a key issue for ensuring the security and reliability of power supply. Based on wavelet packet decomposition technology and random forest algorithm, an effective identification system was developed in this paper. First, compared with the incomplete description of Shannon entropy, the wavelet packet time-frequency energy rate (WTFER) was adopted as the input vector for the classifier model in the feature selection procedure. Then, a random forest classifier was used to diagnose the HVCB fault, assess the importance of the feature variable and optimize the feature space. Finally, the approach was verified based on actual HVCB vibration signals by considering six typical fault classes. The comparative experiment results show that the classification accuracy of the proposed method with the origin feature space reached 93.33% and reached up to 95.56% with optimized input feature vector of classifier. This indicates that feature optimization procedure is successful, and the proposed diagnosis algorithm has higher efficiency and robustness than traditional methods.

Bias Correction and Random Error Characterization for the Assimilation of HRDI Line-of-Sight Wind Measurements

Science.gov (United States)

Tangborn, Andrew; Menard, Richard; Ortland, David; Einaudi, Franco (Technical Monitor)

2001-01-01

A new approach to the analysis of systematic and random observation errors is presented in which the error statistics are obtained using forecast data rather than observations from a different instrument type. The analysis is carried out at an intermediate retrieval level, instead of the more typical state variable space. This method is carried out on measurements made by the High Resolution Doppler Imager (HRDI) on board the Upper Atmosphere Research Satellite (UARS). HRDI, a limb sounder, is the only satellite instrument measuring winds in the stratosphere, and the only instrument of any kind making global wind measurements in the upper atmosphere. HRDI measures doppler shifts in the two different O2 absorption bands (alpha and B) and the retrieved products are tangent point Line-of-Sight wind component (level 2 retrieval) and UV winds (level 3 retrieval). This analysis is carried out on a level 1.9 retrieval, in which the contributions from different points along the line-of-sight have not been removed. Biases are calculated from O-F (observed minus forecast) LOS wind components and are separated into a measurement parameter space consisting of 16 different values. The bias dependence on these parameters (plus an altitude dependence) is used to create a bias correction scheme carried out on the level 1.9 retrieval. The random error component is analyzed by separating the gamma and B band observations and locating observation pairs where both bands are very nearly looking at the same location at the same time. It is shown that the two observation streams are uncorrelated and that this allows the forecast error variance to be estimated. The bias correction is found to cut the effective observation error variance in half.

Threshold-Based Random Charging Scheme for Decentralized PEV Charging Operation in a Smart Grid.

Science.gov (United States)

Kwon, Ojin; Kim, Pilkee; Yoon, Yong-Jin

2016-12-26

Smart grids have been introduced to replace conventional power distribution systems without real time monitoring for accommodating the future market penetration of plug-in electric vehicles (PEVs). When a large number of PEVs require simultaneous battery charging, charging coordination techniques have become one of the most critical factors to optimize the PEV charging performance and the conventional distribution system. In this case, considerable computational complexity of a central controller and exchange of real time information among PEVs may occur. To alleviate these problems, a novel threshold-based random charging (TBRC) operation for a decentralized charging system is proposed. Using PEV charging thresholds and random access rates, the PEVs themselves can participate in the charging requests. As PEVs with a high battery state do not transmit the charging requests to the central controller, the complexity of the central controller decreases due to the reduction of the charging requests. In addition, both the charging threshold and the random access rate are statistically calculated based on the average of supply power of the PEV charging system that do not require a real time update. By using the proposed TBRC with a tolerable PEV charging degradation, a 51% reduction of the PEV charging requests is achieved.

European wet deposition maps based on measurements

NARCIS (Netherlands)

Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO

1995-01-01

To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

Prediction of plant promoters based on hexamers and random triplet pair analysis

Directory of Open Access Journals (Sweden)

Noman Nasimul

2011-06-01

Full Text Available Abstract Background With an increasing number of plant genome sequences, it has become important to develop a robust computational method for detecting plant promoters. Although a wide variety of programs are currently available, prediction accuracy of these still requires further improvement. The limitations of these methods can be addressed by selecting appropriate features for distinguishing promoters and non-promoters. Methods In this study, we proposed two feature selection approaches based on hexamer sequences: the Frequency Distribution Analyzed Feature Selection Algorithm (FDAFSA and the Random Triplet Pair Feature Selecting Genetic Algorithm (RTPFSGA. In FDAFSA, adjacent triplet-pairs (hexamer sequences were selected based on the difference in the frequency of hexamers between promoters and non-promoters. In RTPFSGA, random triplet-pairs (RTPs were selected by exploiting a genetic algorithm that distinguishes frequencies of non-adjacent triplet pairs between promoters and non-promoters. Then, a support vector machine (SVM, a nonlinear machine-learning algorithm, was used to classify promoters and non-promoters by combining these two feature selection approaches. We referred to this novel algorithm as PromoBot. Results Promoter sequences were collected from the PlantProm database. Non-promoter sequences were collected from plant mRNA, rRNA, and tRNA of PlantGDB and plant miRNA of miRBase. Then, in order to validate the proposed algorithm, we applied a 5-fold cross validation test. Training data sets were used to select features based on FDAFSA and RTPFSGA, and these features were used to train the SVM. We achieved 89% sensitivity and 86% specificity. Conclusions We compared our PromoBot algorithm to five other algorithms. It was found that the sensitivity and specificity of PromoBot performed well (or even better with the algorithms tested. These results show that the two proposed feature selection methods based on hexamer frequencies

Random Item Generation Is Affected by Age

Science.gov (United States)

Multani, Namita; Rudzicz, Frank; Wong, Wing Yiu Stephanie; Namasivayam, Aravind Kumar; van Lieshout, Pascal

2016-01-01

Purpose: Random item generation (RIG) involves central executive functioning. Measuring aspects of random sequences can therefore provide a simple method to complement other tools for cognitive assessment. We examine the extent to which RIG relates to specific measures of cognitive function, and whether those measures can be estimated using RIG…

Measurement-based reliability/performability models

Science.gov (United States)

Hsueh, Mei-Chen

1987-01-01

Measurement-based models based on real error-data collected on a multiprocessor system are described. Model development from the raw error-data to the estimation of cumulative reward is also described. A workload/reliability model is developed based on low-level error and resource usage data collected on an IBM 3081 system during its normal operation in order to evaluate the resource usage/error/recovery process in a large mainframe system. Thus, both normal and erroneous behavior of the system are modeled. The results provide an understanding of the different types of errors and recovery processes. The measured data show that the holding times in key operational and error states are not simple exponentials and that a semi-Markov process is necessary to model the system behavior. A sensitivity analysis is performed to investigate the significance of using a semi-Markov process, as opposed to a Markov process, to model the measured system.

Effect of Yoga Based Lifestyle Intervention on Patients With Knee Osteoarthritis: A Randomized Controlled Trial

Science.gov (United States)

Deepeshwar, Singh; Tanwar, Monika; Kavuri, Vijaya; Budhi, Rana B.

2018-01-01

Objective: To investigate the effect of integrated approach of yoga therapy (IAYT) intervention in individual with knee Osteoarthritis. Design: Randomized controlled clincial trail. Participants: Sixty-six individual prediagnosed with knee osteoarthritis aged between 30 and 75 years were randomized into two groups, i.e., Yoga (n = 31) and Control (n = 35). Yoga group received IAYT intervention for 1 week at yoga center of S-VYASA whereas Control group maintained their normal lifestyle. Outcome measures: The Falls Efficacy Scale (FES), Handgrip Strength test (left hand LHGS and right hand RHGS), Timed Up and Go Test (TUG), Sit-to-Stand (STS), and right & left extension and flexion were measured on day 1 and day 7. Results: There were a significant reduction in TUG (p Yoga group. Conclusion: IAYT practice showed an improvement in TUG, STS, HGS, and Goniometer test, which suggest improved muscular strength, flexibility, and functional mobility. CTRI Registration Number: http://ctri.nic.in/Clinicaltrials, identifier CTRI/2017/10/010141. PMID:29867604

Web app based patient education in psoriasis - a randomized controlled trial.

Science.gov (United States)

Hawkins, Spencer D; Barilla, Steven; Feldman, Steven R

2017-04-15

Patients report wanting more information about psoriasis and clear expectations from the onset of therapy. Dermatologists do not think patients receive or internalize adequate information. There isa need for further explanation of treatment regimens to increase knowledge, compliance, and patient satisfaction. Recent advancements in web technology have the potential to improve these psoriasis outcomes. A web based application was created to educate psoriasis patients using video, graphics, and textual information. An investigator blinded, randomized, controlled study evaluated the website's efficacy in 50 psoriasis patients at Wake Forest Baptist Health Dermatology. Patients were randomized into two groups: Group 1 received a link to the educational web app and a survey following their visit; Group 2 received a link to the survey with no educational web app. The survey assessed patient knowledge, self reported adherence to medication, and adequacy of addressing concerns. Twenty two patients completed the study. Patients in the web app group scored an average of 11/14 on the psoriasis knowledge quiz, whereas patients in the control group scored an average of 9/14 for an improvement of roughly 18% (p=0.008, n=22). Web app based education via DermPatientEd.Com is an efficient way to improve knowledge, but we did not demonstrate improvements in self-reported medication adherence or the ability to address concerns of psoriasis patients.

Dynamic approach to space and habitat use based on biased random bridges.

Directory of Open Access Journals (Sweden)

Simon Benhamou

Full Text Available BACKGROUND: Although habitat use reflects a dynamic process, most studies assess habitat use statically as if an animal's successively recorded locations reflected a point rather than a movement process. By relying on the activity time between successive locations instead of the local density of individual locations, movement-based methods can substantially improve the biological relevance of utilization distribution (UD estimates (i.e. the relative frequencies with which an animal uses the various areas of its home range, HR. One such method rests on Brownian bridges (BBs. Its theoretical foundation (purely and constantly diffusive movements is paradoxically inconsistent with both HR settlement and habitat selection. An alternative involves movement-based kernel density estimation (MKDE through location interpolation, which may be applied to various movement behaviours but lacks a sound theoretical basis. METHODOLOGY/PRINCIPAL FINDINGS: I introduce the concept of a biased random (advective-diffusive bridge (BRB and show that the MKDE method is a practical means to estimate UDs based on simplified (isotropically diffusive BRBs. The equation governing BRBs is constrained by the maximum delay between successive relocations warranting constant within-bridge advection (allowed to vary between bridges but remains otherwise similar to the BB equation. Despite its theoretical inconsistencies, the BB method can therefore be applied to animals that regularly reorientate within their HRs and adapt their movements to the habitats crossed, provided that they were relocated with a high enough frequency. CONCLUSIONS/SIGNIFICANCE: Biased random walks can approximate various movement types at short times from a given relocation. Their simplified form constitutes an effective trade-off between too simple, unrealistic movement models, such as Brownian motion, and more sophisticated and realistic ones, such as biased correlated random walks (BCRWs, which are too

Study on Stationarity of Random Load Spectrum Based on the Special Road

Science.gov (United States)

Yan, Huawen; Zhang, Weigong; Wang, Dong

2017-09-01

In the special road quality assessment method, there is a method using a wheel force sensor, the essence of this method is collecting the load spectrum of the car to reflect the quality of road. According to the definition of stochastic process, it is easy to find that the load spectrum is a stochastic process. However, the analysis method and application range of different random processes are very different, especially in engineering practice, which will directly affect the design and development of the experiment. Therefore, determining the type of a random process has important practical significance. Based on the analysis of the digital characteristics of road load spectrum, this paper determines that the road load spectrum in this experiment belongs to a stationary stochastic process, paving the way for the follow-up modeling and feature extraction of the special road.

An open randomized controlled study comparing an online text-based scenario and a serious game by Belgian and Swiss pharmacy students.

Science.gov (United States)

Berger, Jérôme; Bawab, Noura; De Mooij, Jeremy; Sutter Widmer, Denise; Szilas, Nicolas; De Vriese, Carine; Bugnon, Olivier

2018-03-01

To compare online learning tools, looped, branch serious game (SG) and linear text-based scenario (TBS), among a sample of Belgian and Swiss pharmacy students. Open randomized controlled study. The lesson was based on the case of a benign cough in a healthy child. A randomized sample of 117 students: only the Swiss students had attended a previous lecture on coughs. Participation rate, pre- and post-experience Likert scales and students' clinical knowledge were measured. Our primary hypothesis was demonstrated: students favored the SG even if navigation was rated as more complex, and students who performed the SG better understood the aim of pharmacist triage in case of cough. The influence of the SG appeared to be linked to the presence of a previous lecture in the curriculum. SG and TBS are effective to teach pharmacist triage. Higher SG complexity should be used to teach the aim of pharmacist triage in the case of a specific disease and could be an alternative to simulated patients. A simpler TBS does not require a previous lecture and a debriefing to be fully effective. Copyright © 2017 Elsevier Inc. All rights reserved.

Specialized home treatment versus hospital-based outpatient treatment for first-episode psychosis: a randomized clinical trial.

Science.gov (United States)

Dewa, Carolyn S; Zipursky, Robert B; Chau, Nancy; Furimsky, Ivana; Collins, April; Agid, Ofer; Goering, Paula

2009-11-01

This pilot study compared the effectiveness of specialized care that was home based versus hospital based for individuals experiencing their first psychotic episode. A randomized controlled trial design was used. A total of 29 subjects were interviewed at baseline, 3 and 9 months. Repeated measures analysis of variance was employed to test for statistically significant changes over time within and between groups with regard to community psychosocial functioning and symptom severity. Our findings indicate that subjects in both the home-based and hospital-based programmes significantly improved with regard to symptoms and community functioning over time. However, the rates of change over time were not significantly different between the two programmes. There was a statistically significant difference between programmes with regard to the proportion of subjects with less than two visits (i.e. either did not attend their first assessment or attended follow-up visits after their assessment). This was a modest pilot study and the sample was too small to allow definitive conclusions to be drawn. However, the results raise questions about differences in initial treatment engagement. They suggest the need for additional research focusing on interventions that promote initial treatment seeking. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Asia Pty Ltd.

Synchronization of random bit generators based on coupled chaotic lasers and application to cryptography.

Science.gov (United States)

Kanter, Ido; Butkovski, Maria; Peleg, Yitzhak; Zigzag, Meital; Aviad, Yaara; Reidler, Igor; Rosenbluh, Michael; Kinzel, Wolfgang

2010-08-16

Random bit generators (RBGs) constitute an important tool in cryptography, stochastic simulations and secure communications. The later in particular has some difficult requirements: high generation rate of unpredictable bit strings and secure key-exchange protocols over public channels. Deterministic algorithms generate pseudo-random number sequences at high rates, however, their unpredictability is limited by the very nature of their deterministic origin. Recently, physical RBGs based on chaotic semiconductor lasers were shown to exceed Gbit/s rates. Whether secure synchronization of two high rate physical RBGs is possible remains an open question. Here we propose a method, whereby two fast RBGs based on mutually coupled chaotic lasers, are synchronized. Using information theoretic analysis we demonstrate security against a powerful computational eavesdropper, capable of noiseless amplification, where all parameters are publicly known. The method is also extended to secure synchronization of a small network of three RBGs.

Quantum random-number generator based on a photon-number-resolving detector

International Nuclear Information System (INIS)

Ren Min; Wu, E; Liang Yan; Jian Yi; Wu Guang; Zeng Heping

2011-01-01

We demonstrated a high-efficiency quantum random number generator which takes inherent advantage of the photon number distribution randomness of a coherent light source. This scheme was realized by comparing the photon flux of consecutive pulses with a photon number resolving detector. The random bit generation rate could reach 2.4 MHz with a system clock of 6.0 MHz, corresponding to a random bit generation efficiency as high as 40%. The random number files passed all the stringent statistical tests.

Fatigue life estimation of MD36 and MD523 bogies based on damage accumulation and random fatigue theory

International Nuclear Information System (INIS)

Younesian, Davood; Solhmirzaei, Ali; Gachloo, Alireza

2009-01-01

Bogies are one of the multifunctional parts of trains which are extremely subjected to random loads. This type of oscillating and random excitation arises from irregularities of the track including rail surface vertical roughness, rail joints, variance in super-elevation, and also wheel imperfections like wheel flats and unbalancy. Since most of the prementioned sources have random nature, a random based theory should be applied for fatigue life estimation of the bogie frame. Two methods of fatigue life estimation are investigated in this paper. The first approach which is being implemented in time domain is based on the damage accumulation (DA) approach. Using Monte-Carlo simulation algorithm, the rail surface roughness is generated. Finite element (FE) model of the bogie is subjected to the generated random excitation in the first approach and the stress time histories are obtained, and consequently the fatigue life is estimated by using the rain-flow algorithm. In the second approach, the fatigue life is estimated in frequency domain. Power spectral density (PSD) of the stress is obtained by using the FE model of the bogie frame and the fatigue life is estimated using Rayleigh technique in random fatigue theory. A comprehensive parametric study is carried out and effects of different parameters like the train speeds and level of the rail surface vertical roughness on the estimated fatigue life are investigated

Multiformity of inherent randomicity and visitation density in n symbolic dynamics

International Nuclear Information System (INIS)

Zhang Yagang; Wang Changjiang

2007-01-01

The multiformity of inherent randomicity and visitation density in n symbolic dynamics will be clarified in this paper. These stochastic symbolic sequences bear three features. The distribution of frequency, inter-occurrence times and the alignment of two random sequences are amplified in detail. The features of visitation density in surjective maps presents catholicity and the catholicity in n letters randomicity has the same measure foundation. We hope to offer a symbolic platform that satisfies these stochastic properties and to attempt to study certain properties of DNA base sequences, 20 amino acids symbolic sequences of proteid structure, and the time series that can be symbolic in finance market et al

Random matrix theory and analysis of nucleus-nucleus collision at high energies

International Nuclear Information System (INIS)

Shahaliev, E.I.; Inst. of Radiation Problems, Baku; ); Kuznetsov, A.A.; Suleymanov, M.K.; ); Teryaev, O.V.; )

2006-01-01

A novel method for analysis of experimental data obtained at relativistic nucleus-nucleus collisions is proposed. The method, based on the ideas of Random Matrix Theory, is applied to detect systematic errors that occur at measurements of momentum distributions of emitted particles. The unfolded momentum distribution is well described by the Gaussian orthogonal ensemble of random matrices, when the uncertainty in the momentum distribution is maximal. The method is free from unwanted background contributions [ru

Efficient Raman generation in a waveguide: A route to ultrafast quantum random number generation

Energy Technology Data Exchange (ETDEWEB)

England, D. G.; Bustard, P. J.; Moffatt, D. J.; Nunn, J.; Lausten, R.; Sussman, B. J., E-mail: ben.sussman@nrc.ca [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada)

2014-02-03

The inherent uncertainty in quantum mechanics offers a source of true randomness which can be used to produce unbreakable cryptographic keys. We discuss the development of a high-speed random number generator based on the quantum phase fluctuations in spontaneously initiated stimulated Raman scattering (SISRS). We utilize the tight confinement and long interaction length available in a Potassium Titanyl Phosphate waveguide to generate highly efficient SISRS using nanojoule pulse energies, reducing the high pump power requirements of the previous approaches. We measure the random phase of the Stokes output using a simple interferometric setup to yield quantum random numbers at 145 Mbps.

rFerns: An Implementation of the Random Ferns Method for General-Purpose Machine Learning

Directory of Open Access Journals (Sweden)

Miron B. Kursa

2014-11-01

Full Text Available Random ferns is a very simple yet powerful classification method originally introduced for specific computer vision tasks. In this paper, I show that this algorithm may be considered as a constrained decision tree ensemble and use this interpretation to introduce a series of modifications which enable the use of random ferns in general machine learning problems. Moreover, I extend the method with an internal error approximation and an attribute importance measure based on corresponding features of the random forest algorithm. I also present the R package rFerns containing an efficient implementation of this modified version of random ferns.

A Cluster Randomized Controlled Trial Testing the Effectiveness of Houvast: A Strengths-Based Intervention for Homeless Young Adults

Science.gov (United States)

Krabbenborg, Manon A. M.; Boersma, Sandra N.; van der Veld, William M.; van Hulst, Bente; Vollebergh, Wilma A. M.; Wolf, Judith R. L. M.

2017-01-01

Objective: To test the effectiveness of Houvast: a strengths-based intervention for homeless young adults. Method: A cluster randomized controlled trial was conducted with 10 Dutch shelter facilities randomly allocated to an intervention and a control group. Homeless young adults were interviewed when entering the facility and when care ended.…

Measuring gas-residence times in large municipal incinerators, by means of a pseudo-random binary signal tracer technique

International Nuclear Information System (INIS)

Nasserzadeh, V.; Swithenbank, J.; Jones, B.

1995-01-01

The problem of measuring gas-residence time in large incinerators was studied by the pseudo-random binary sequence (PRBS) stimulus tracer response technique at the Sheffield municipal solid-waste incinerator (35 MW plant). The steady-state system was disturbed by the superimposition of small fluctuations in the form of a pseudo-random binary sequence of methane pulses, and the response of the incinerator was determined from the CO 2 concentration in flue gases at the boiler exit, measured with a specially developed optical gas analyser with a high-frequency response. For data acquisition, an on-line PC computer was used together with the LAB Windows software system; the output response was then cross-correlated with the perturbation signal to give the impulse response of the incinerator. There was very good agreement between the gas-residence time for the Sheffield MSW incinerator as calculated by computational fluid dynamics (FLUENT Model) and gas-residence time at the plant as measured by the PRBS tracer technique. The results obtained from this research programme clearly demonstrate that the PRBS stimulus tracer response technique can be successfully and economically used to measure gas-residence times in large incinerator plants. It also suggests that the common commercial practice of characterising the incinerator operation by a single-residence-time parameter may lead to a misrepresentation of the complexities involved in describing the operation of the incineration system. (author)

Possibility/Necessity-Based Probabilistic Expectation Models for Linear Programming Problems with Discrete Fuzzy Random Variables

Directory of Open Access Journals (Sweden)

Hideki Katagiri

2017-10-01

Full Text Available This paper considers linear programming problems (LPPs where the objective functions involve discrete fuzzy random variables (fuzzy set-valued discrete random variables. New decision making models, which are useful in fuzzy stochastic environments, are proposed based on both possibility theory and probability theory. In multi-objective cases, Pareto optimal solutions of the proposed models are newly defined. Computational algorithms for obtaining the Pareto optimal solutions of the proposed models are provided. It is shown that problems involving discrete fuzzy random variables can be transformed into deterministic nonlinear mathematical programming problems which can be solved through a conventional mathematical programming solver under practically reasonable assumptions. A numerical example of agriculture production problems is given to demonstrate the applicability of the proposed models to real-world problems in fuzzy stochastic environments.

Pronounceability: a measure of language samples based on children's mastery of the phonemes employed in them.

Science.gov (United States)

Whissell, Cynthia

2003-06-01

56 samples (n > half a million phonemes) of names (e.g., men's, women's jets'), song lyrics (e.g., Paul Simon's, rap, Beatles'), poems (frequently anthologized English poems), and children's materials (books directed at children ages 3-10 years) were used to study a proposed new measure of English language samples--Pronounceability-based on children's mastery of some phonemes in advance of others. This measure was provisionally equated with greater "youthfulness" and "playfulness" in language samples and with less "maturity." Findings include the facts that women's names were less pronounceable than men's and that poetry was less pronounceable than song lyrics or children's materials. In a supplementary study, 13 university student volunteers' assessments of the youth of randomly constructed names was linearly related to how pronounceable each name was (eta = .8), providing construct validity for the interpretation of Pronounceability as a measure of Youthfulness.

Effectiveness in practice-based research: Looking for alternatives to the randomized controlled trial (RCT)

NARCIS (Netherlands)

Tavecchio, L.

2015-01-01

Over the last decade, the status of the randomized controlled trial (RCT), hallmark of evidence-based medicine (research), has been growing strongly in general practice, social work and public health. But this type of research is only practicable under strictly controlled and well-defined settings

Random discrete Morse theory and a new library of triangulations

DEFF Research Database (Denmark)

Benedetti, Bruno; Lutz, Frank Hagen

2014-01-01

We introduce random discrete Morse theory as a computational scheme to measure the complexity of a triangulation. The idea is to try to quantify the frequency of discrete Morse matchings with few critical cells. Our measure will depend on the topology of the space, but also on how nicely the space...... is triangulated. The scheme we propose looks for optimal discrete Morse functions with an elementary random heuristic. Despite its naiveté, this approach turns out to be very successful even in the case of huge inputs. In our view, the existing libraries of examples in computational topology are “too easy......” for testing algorithms based on discrete Morse theory. We propose a new library containing more complicated (and thus more meaningful) test examples....

Ultra-photo-stable coherent random laser based on liquid waveguide gain channels doped with boehmite nanosheets

Science.gov (United States)

Zhang, Hua; Zhang, Hong; Yang, Chao; Dai, Jiangyun; Yin, Jiajia; Xue, Hongyan; Feng, Guoying; Zhou, Shouhuan

2018-02-01

Construction of ultra-photo-stable coherent random laser based on liquid waveguide gain channels doped with boehmite nanosheets has been demonstrated. An Al plate uniformly coated with boehmite nanosheets was prepared by an alkali-treatment method and used as a scattering surface for the coherent random laser. Microcavity may be formed between these boehmite nanosheets owing to the strong optical feedback induced by the multiple light scattering. Many sharp peaks are observed in the emission spectra, and their laser thresholds are different, which confirms the feedback mechanism is coherent. The linewidth of the main peak at 571.74 nm is 0.28 nm, and the threshold of the main peak is about 4.96 mJ/cm2. Due to the fluidity of liquid waveguide gain medium, the photostability of this coherent random laser is better than the conventional solid state dye random lasers. The emission direction is well constrained by the waveguide effect within a certain angular range (±30°). This kind of coherent random laser can be applied in optical fluid lasers and photonic devices.

Optical image transformation and encryption by phase-retrieval-based double random-phase encoding and compressive ghost imaging

Science.gov (United States)

Yuan, Sheng; Yang, Yangrui; Liu, Xuemei; Zhou, Xin; Wei, Zhenzhuo

2018-01-01

An optical image transformation and encryption scheme is proposed based on double random-phase encoding (DRPE) and compressive ghost imaging (CGI) techniques. In this scheme, a secret image is first transformed into a binary image with the phase-retrieval-based DRPE technique, and then encoded by a series of random amplitude patterns according to the ghost imaging (GI) principle. Compressive sensing, corrosion and expansion operations are implemented to retrieve the secret image in the decryption process. This encryption scheme takes the advantage of complementary capabilities offered by the phase-retrieval-based DRPE and GI-based encryption techniques. That is the phase-retrieval-based DRPE is used to overcome the blurring defect of the decrypted image in the GI-based encryption, and the CGI not only reduces the data amount of the ciphertext, but also enhances the security of DRPE. Computer simulation results are presented to verify the performance of the proposed encryption scheme.

3D exemplar-based random walks for tooth segmentation from cone-beam computed tomography images

Energy Technology Data Exchange (ETDEWEB)

Pei, Yuru, E-mail: peiyuru@cis.pku.edu.cn; Ai, Xingsheng; Zha, Hongbin [Department of Machine Intelligence, School of EECS, Peking University, Beijing 100871 (China); Xu, Tianmin [School of Stomatology, Stomatology Hospital, Peking University, Beijing 100081 (China); Ma, Gengyu [uSens, Inc., San Jose, California 95110 (United States)

2016-09-15

Purpose: Tooth segmentation is an essential step in acquiring patient-specific dental geometries from cone-beam computed tomography (CBCT) images. Tooth segmentation from CBCT images is still a challenging task considering the comparatively low image quality caused by the limited radiation dose, as well as structural ambiguities from intercuspation and nearby alveolar bones. The goal of this paper is to present and discuss the latest accomplishments in semisupervised tooth segmentation with adaptive 3D shape constraints. Methods: The authors propose a 3D exemplar-based random walk method of tooth segmentation from CBCT images. The proposed method integrates semisupervised label propagation and regularization by 3D exemplar registration. To begin with, the pure random walk method is to get an initial segmentation of the teeth, which tends to be erroneous because of the structural ambiguity of CBCT images. And then, as an iterative refinement, the authors conduct a regularization by using 3D exemplar registration, as well as label propagation by random walks with soft constraints, to improve the tooth segmentation. In the first stage of the iteration, 3D exemplars with well-defined topologies are adapted to fit the tooth contours, which are obtained from the random walks based segmentation. The soft constraints on voxel labeling are defined by shape-based foreground dentine probability acquired by the exemplar registration, as well as the appearance-based probability from a support vector machine (SVM) classifier. In the second stage, the labels of the volume-of-interest (VOI) are updated by the random walks with soft constraints. The two stages are optimized iteratively. Instead of the one-shot label propagation in the VOI, an iterative refinement process can achieve a reliable tooth segmentation by virtue of exemplar-based random walks with adaptive soft constraints. Results: The proposed method was applied for tooth segmentation of twenty clinically captured CBCT

Internet-delivered eating disorder prevention: A randomized controlled trial of dissonance-based and cognitive-behavioral interventions.

Science.gov (United States)

Chithambo, Taona P; Huey, Stanley J

2017-10-01

The current study evaluated two web-based programs for eating disorder prevention in high-risk, predominantly ethnic minority women. Two hundred and seventy-one women with elevated weight concerns were randomized to Internet dissonance-based intervention (DBI-I), Internet cognitive-behavioral intervention (CBI-I), or no intervention (NI). Both interventions consisted of four weekly online sessions. Participants were assessed at pre- and post intervention. Outcome measures included eating pathology, body dissatisfaction, dieting, thin-ideal internalization, and depression. At postintervention, DBI-I and CBI-I led to greater reductions in body dissatisfaction, thin-ideal internalization, and depression than NI. In addition, CBI-I was effective at reducing dieting and composite eating pathology relative to NI. No outcome differences were found between the active conditions. Moderation analyses suggested that both active conditions were more effective for ethnic minorities than Whites relative to NI. Results suggest that both DBI-I and CBI-I are effective at reducing eating disorder risk factors in a high-risk, predominantly minority population relative to no intervention. © 2017 Wiley Periodicals, Inc.

A random walk model to evaluate autism

Science.gov (United States)

Moura, T. R. S.; Fulco, U. L.; Albuquerque, E. L.

2018-02-01

A common test administered during neurological examination in children is the analysis of their social communication and interaction across multiple contexts, including repetitive patterns of behavior. Poor performance may be associated with neurological conditions characterized by impairments in executive function, such as the so-called pervasive developmental disorders (PDDs), a particular condition of the autism spectrum disorders (ASDs). Inspired in these diagnosis tools, mainly those related to repetitive movements and behaviors, we studied here how the diffusion regimes of two discrete-time random walkers, mimicking the lack of social interaction and restricted interests developed for children with PDDs, are affected. Our model, which is based on the so-called elephant random walk (ERW) approach, consider that one of the random walker can learn and imitate the microscopic behavior of the other with probability f (1 - f otherwise). The diffusion regimes, measured by the Hurst exponent (H), is then obtained, whose changes may indicate a different degree of autism.

Effectiveness of aquatic exercise and balneotherapy: a summary of systematic reviews based on randomized controlled trials of water immersion therapies.

Science.gov (United States)