High-Dose-Rate Brachytherapy Boost for Prostate Cancer: Comparison of Two Different Fractionation Schemes

International Nuclear Information System (INIS)

Kaprealian, Tania; Weinberg, Vivian; Speight, Joycelyn L.; Gottschalk, Alexander R.; Roach, Mack; Shinohara, Katsuto; Hsu, I.-Chow

2012-01-01

Purpose: This is a retrospective study comparing our experience with high-dose-rate (HDR) brachytherapy boost for prostate cancer, using two different fractionation schemes, 600 cGy × 3 fractions (patient group 1) and 950 cGy × 2 fractions (patient group 2). Methods and Materials: A total of 165 patients were treated for prostate cancer using external beam radiation therapy up to a dose of 45 Gy, followed by an HDR brachytherapy prostate radiation boost. Between July 1997 and Nov 1999, 64 patients were treated with an HDR boost of 600 cGy × 3 fractions; and between June 2000 and Nov 2005, 101 patients were treated with an HDR boost of 950 cGy × 2 fractions. All but 9 patients had at least one of the following risk features: pretreatment prostate-specific antigen (PSA) level >10, a Gleason score ≥7, and/or clinical stage T3 disease. Results: Median follow-up was 105 months for group 1 and 43 months for group 2. Patients in group 2 had a greater number of high-risk features than group 1 (p = 0.02). Adjusted for comparable follow-up, there was no difference in biochemical no-evidence-of-disease (bNED) rate between the two fractionation scheme approaches, with 5-year Kaplan-Meier estimates of 93.5% in group 1 and 87.3% in group 2 (p = 0.19). The 5-year estimates of progression-free survival were 86% for group 1 and 83% for group 2 (p = 0.53). Among high-risk patients, there were no differences in bNED or PFS rate due to fractionation. Conclusions: Results were excellent for both groups. Adjusted for comparable follow-up, no differences were found between groups.

Accelerated Simplified Swarm Optimization with Exploitation Search Scheme for Data Clustering.

Directory of Open Access Journals (Sweden)

Wei-Chang Yeh

Full Text Available Data clustering is commonly employed in many disciplines. The aim of clustering is to partition a set of data into clusters, in which objects within the same cluster are similar and dissimilar to other objects that belong to different clusters. Over the past decade, the evolutionary algorithm has been commonly used to solve clustering problems. This study presents a novel algorithm based on simplified swarm optimization, an emerging population-based stochastic optimization approach with the advantages of simplicity, efficiency, and flexibility. This approach combines variable vibrating search (VVS and rapid centralized strategy (RCS in dealing with clustering problem. VVS is an exploitation search scheme that can refine the quality of solutions by searching the extreme points nearby the global best position. RCS is developed to accelerate the convergence rate of the algorithm by using the arithmetic average. To empirically evaluate the performance of the proposed algorithm, experiments are examined using 12 benchmark datasets, and corresponding results are compared with recent works. Results of statistical analysis indicate that the proposed algorithm is competitive in terms of the quality of solutions.

Particle Simulation of Fractional Diffusion Equations

KAUST Repository

Allouch, Samer

2017-07-12

This work explores different particle-based approaches to the simulation of one-dimensional fractional subdiffusion equations in unbounded domains. We rely on smooth particle approximations, and consider four methods for estimating the fractional diffusion term. The first method is based on direct differentiation of the particle representation, it follows the Riesz definition of the fractional derivative and results in a non-conservative scheme. The other three methods follow the particle strength exchange (PSE) methodology and are by construction conservative, in the sense that the total particle strength is time invariant. The first PSE algorithm is based on using direct differentiation to estimate the fractional diffusion flux, and exploiting the resulting estimates in an integral representation of the divergence operator. Meanwhile, the second one relies on the regularized Riesz representation of the fractional diffusion term to derive a suitable interaction formula acting directly on the particle representation of the diffusing field. A third PSE construction is considered that exploits the Green\\'s function of the fractional diffusion equation. The performance of all four approaches is assessed for the case of a one-dimensional diffusion equation with constant diffusivity. This enables us to take advantage of known analytical solutions, and consequently conduct a detailed analysis of the performance of the methods. This includes a quantitative study of the various sources of error, namely filtering, quadrature, domain truncation, and time integration, as well as a space and time self-convergence analysis. These analyses are conducted for different values of the order of the fractional derivatives, and computational experiences are used to gain insight that can be used for generalization of the present constructions.

Particle Simulation of Fractional Diffusion Equations

KAUST Repository

Allouch, Samer; Lucchesi, Marco; Maî tre, O. P. Le; Mustapha, K. A.; Knio, Omar

2017-01-01

This work explores different particle-based approaches to the simulation of one-dimensional fractional subdiffusion equations in unbounded domains. We rely on smooth particle approximations, and consider four methods for estimating the fractional diffusion term. The first method is based on direct differentiation of the particle representation, it follows the Riesz definition of the fractional derivative and results in a non-conservative scheme. The other three methods follow the particle strength exchange (PSE) methodology and are by construction conservative, in the sense that the total particle strength is time invariant. The first PSE algorithm is based on using direct differentiation to estimate the fractional diffusion flux, and exploiting the resulting estimates in an integral representation of the divergence operator. Meanwhile, the second one relies on the regularized Riesz representation of the fractional diffusion term to derive a suitable interaction formula acting directly on the particle representation of the diffusing field. A third PSE construction is considered that exploits the Green's function of the fractional diffusion equation. The performance of all four approaches is assessed for the case of a one-dimensional diffusion equation with constant diffusivity. This enables us to take advantage of known analytical solutions, and consequently conduct a detailed analysis of the performance of the methods. This includes a quantitative study of the various sources of error, namely filtering, quadrature, domain truncation, and time integration, as well as a space and time self-convergence analysis. These analyses are conducted for different values of the order of the fractional derivatives, and computational experiences are used to gain insight that can be used for generalization of the present constructions.

Chaos-based partial image encryption scheme based on linear fractional and lifting wavelet transforms

Science.gov (United States)

Belazi, Akram; Abd El-Latif, Ahmed A.; Diaconu, Adrian-Viorel; Rhouma, Rhouma; Belghith, Safya

2017-01-01

In this paper, a new chaos-based partial image encryption scheme based on Substitution-boxes (S-box) constructed by chaotic system and Linear Fractional Transform (LFT) is proposed. It encrypts only the requisite parts of the sensitive information in Lifting-Wavelet Transform (LWT) frequency domain based on hybrid of chaotic maps and a new S-box. In the proposed encryption scheme, the characteristics of confusion and diffusion are accomplished in three phases: block permutation, substitution, and diffusion. Then, we used dynamic keys instead of fixed keys used in other approaches, to control the encryption process and make any attack impossible. The new S-box was constructed by mixing of chaotic map and LFT to insure the high confidentiality in the inner encryption of the proposed approach. In addition, the hybrid compound of S-box and chaotic systems strengthened the whole encryption performance and enlarged the key space required to resist the brute force attacks. Extensive experiments were conducted to evaluate the security and efficiency of the proposed approach. In comparison with previous schemes, the proposed cryptosystem scheme showed high performances and great potential for prominent prevalence in cryptographic applications.

Hybrid flux splitting schemes for numerical resolution of two-phase flows

Energy Technology Data Exchange (ETDEWEB)

Flaatten, Tore

2003-07-01

This thesis deals with the construction of numerical schemes for approximating. solutions to a hyperbolic two-phase flow model. Numerical schemes for hyperbolic models are commonly divided in two main classes: Flux Vector Splitting (FVS) schemes which are based on scalar computations and Flux Difference Splitting (FDS) schemes which are based on matrix computations. FVS schemes are more efficient than FDS schemes, but FDS schemes are more accurate. The canonical FDS schemes are the approximate Riemann solvers which are based on a local decomposition of the system into its full wave structure. In this thesis the mathematical structure of the model is exploited to construct a class of hybrid FVS/FDS schemes, denoted as Mixture Flux (MF) schemes. This approach is based on a splitting of the system in two components associated with the pressure and volume fraction variables respectively, and builds upon hybrid FVS/FDS schemes previously developed for one-phase flow models. Through analysis and numerical experiments it is demonstrated that the MF approach provides several desirable features, including (1) Improved efficiency compared to standard approximate Riemann solvers, (2) Robustness under stiff conditions, (3) Accuracy on linear and nonlinear phenomena. In particular it is demonstrated that the framework allows for an efficient weakly implicit implementation, focusing on an accurate resolution of slow transients relevant for the petroleum industry. (author)

Analytical incorporation of fractionation effects in probabilistic treatment planning for intensity-modulated proton therapy.

Science.gov (United States)

Wahl, Niklas; Hennig, Philipp; Wieser, Hans-Peter; Bangert, Mark

2018-04-01

reduced fraction number and/or for more robust treatment plans. By explicit consideration of fractionation effects during planning, we demonstrate that it is possible to exploit this trade-off during optimization. APM optimization considering the fraction number reduced the dose in organs at risk compared to conventional probabilistic optimization neglecting the fraction number. APM enables computationally efficient incorporation of fractionation effects in probabilistic uncertainty analysis and probabilistic treatment plan optimization. The consideration of the fractionation scheme in probabilistic treatment planning reveals the trade-off between number of fractions, nominal dose, and treatment plan robustness. © 2018 American Association of Physicists in Medicine.

The Quasar Fraction in Low-Frequency Selected Complete Samples and Implications for Unified Schemes

Science.gov (United States)

Willott, Chris J.; Rawlings, Steve; Blundell, Katherine M.; Lacy, Mark

2000-01-01

Low-frequency radio surveys are ideal for selecting orientation-independent samples of extragalactic sources because the sample members are selected by virtue of their isotropic steep-spectrum extended emission. We use the new 7C Redshift Survey along with the brighter 3CRR and 6C samples to investigate the fraction of objects with observed broad emission lines - the 'quasar fraction' - as a function of redshift and of radio and narrow emission line luminosity. We find that the quasar fraction is more strongly dependent upon luminosity (both narrow line and radio) than it is on redshift. Above a narrow [OII] emission line luminosity of log(base 10) (L(sub [OII])/W) approximately > 35 [or radio luminosity log(base 10) (L(sub 151)/ W/Hz.sr) approximately > 26.5], the quasar fraction is virtually independent of redshift and luminosity; this is consistent with a simple unified scheme with an obscuring torus with a half-opening angle theta(sub trans) approximately equal 53 deg. For objects with less luminous narrow lines, the quasar fraction is lower. We show that this is not due to the difficulty of detecting lower-luminosity broad emission lines in a less luminous, but otherwise similar, quasar population. We discuss evidence which supports at least two probable physical causes for the drop in quasar fraction at low luminosity: (i) a gradual decrease in theta(sub trans) and/or a gradual increase in the fraction of lightly-reddened (0 approximately quasar luminosity; and (ii) the emergence of a distinct second population of low luminosity radio sources which, like M8T, lack a well-fed quasar nucleus and may well lack a thick obscuring torus.

The data cyclotron query processing scheme

NARCIS (Netherlands)

R.A. Goncalves (Romulo); M.L. Kersten (Martin)

2010-01-01

htmlabstractDistributed database systems exploit static workload characteristics to steer data fragmentation and data allocation schemes. However, the grand challenge of distributed query processing is to come up with a self-organizing architecture, which exploits all resources to manage the hot

Fractional corresponding operator in quantum mechanics and applications: A uniform fractional Schrödinger equation in form and fractional quantization methods

International Nuclear Information System (INIS)

Zhang, Xiao; Wei, Chaozhen; Liu, Yingming; Luo, Maokang

2014-01-01

In this paper we use Dirac function to construct a fractional operator called fractional corresponding operator, which is the general form of momentum corresponding operator. Then we give a judging theorem for this operator and with this judging theorem we prove that R–L, G–L, Caputo, Riesz fractional derivative operator and fractional derivative operator based on generalized functions, which are the most popular ones, coincide with the fractional corresponding operator. As a typical application, we use the fractional corresponding operator to construct a new fractional quantization scheme and then derive a uniform fractional Schrödinger equation in form. Additionally, we find that the five forms of fractional Schrödinger equation belong to the particular cases. As another main result of this paper, we use fractional corresponding operator to generalize fractional quantization scheme by using Lévy path integral and use it to derive the corresponding general form of fractional Schrödinger equation, which consequently proves that these two quantization schemes are equivalent. Meanwhile, relations between the theory in fractional quantum mechanics and that in classic quantum mechanics are also discussed. As a physical example, we consider a particle in an infinite potential well. We give its wave functions and energy spectrums in two ways and find that both results are the same

3D positioning scheme exploiting nano-scale IR-UWB orthogonal pulses.

Science.gov (United States)

Kim, Nammoon; Kim, Youngok

2011-10-04

In these days, the development of positioning technology for realizing ubiquitous environments has become one of the most important issues. The Global Positioning System (GPS) is a well-known positioning scheme, but it is not suitable for positioning in in-door/building environments because it is difficult to maintain line-of-sight condition between satellites and a GPS receiver. To such problem, various positioning methods such as RFID, WLAN, ZigBee, and Bluetooth have been developed for indoor positioning scheme. However, the majority of positioning schemes are focused on the two-dimension positioning even though three-dimension (3D) positioning information is more useful especially in indoor applications, such as smart space, U-health service, context aware service, etc. In this paper, a 3D positioning system based on mutually orthogonal nano-scale impulse radio ultra-wideband (IR-UWB) signals and cross array antenna is proposed. The proposed scheme uses nano-scale IR-UWB signals providing fine time resolution and high-resolution multiple signal specification algorithm for the time-of-arrival and the angle-of-arrival estimation. The performance is evaluated over various IEEE 802.15.4a channel models, and simulation results show the effectiveness of proposed scheme.

3D positioning scheme exploiting nano-scale IR-UWB orthogonal pulses

Directory of Open Access Journals (Sweden)

Kim Nammoon

2011-01-01

Full Text Available Abstract In these days, the development of positioning technology for realizing ubiquitous environments has become one of the most important issues. The Global Positioning System (GPS is a well-known positioning scheme, but it is not suitable for positioning in in-door/building environments because it is difficult to maintain line-of-sight condition between satellites and a GPS receiver. To such problem, various positioning methods such as RFID, WLAN, ZigBee, and Bluetooth have been developed for indoor positioning scheme. However, the majority of positioning schemes are focused on the two-dimension positioning even though three-dimension (3D positioning information is more useful especially in indoor applications, such as smart space, U-health service, context aware service, etc. In this paper, a 3D positioning system based on mutually orthogonal nano-scale impulse radio ultra-wideband (IR-UWB signals and cross array antenna is proposed. The proposed scheme uses nano-scale IR-UWB signals providing fine time resolution and high-resolution multiple signal specification algorithm for the time-of-arrival and the angle-of-arrival estimation. The performance is evaluated over various IEEE 802.15.4a channel models, and simulation results show the effectiveness of proposed scheme.

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

Science.gov (United States)

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

2018-05-15

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

A quantum-mechanics molecular-mechanics scheme for extended systems

International Nuclear Information System (INIS)

Hunt, Diego; Scherlis, Damián A; Sanchez, Veronica M

2016-01-01

We introduce and discuss a hybrid quantum-mechanics molecular-mechanics (QM-MM) approach for Car–Parrinello DFT simulations with pseudopotentials and planewaves basis, designed for the treatment of periodic systems. In this implementation the MM atoms are considered as additional QM ions having fractional charges of either sign, which provides conceptual and computational simplicity by exploiting the machinery already existing in planewave codes to deal with electrostatics in periodic boundary conditions. With this strategy, both the QM and MM regions are contained in the same supercell, which determines the periodicity for the whole system. Thus, while this method is not meant to compete with non-periodic QM-MM schemes able to handle extremely large but finite MM regions, it is shown that for periodic systems of a few hundred atoms, our approach provides substantial savings in computational times by treating classically a fraction of the particles. The performance and accuracy of the method is assessed through the study of energetic, structural, and dynamical aspects of the water dimer and of the aqueous bulk phase. Finally, the QM-MM scheme is applied to the computation of the vibrational spectra of water layers adsorbed at the TiO 2 anatase (1 0 1) solid–liquid interface. This investigation suggests that the inclusion of a second monolayer of H 2 O molecules is sufficient to induce on the first adsorbed layer, a vibrational dynamics similar to that taking place in the presence of an aqueous environment. The present QM-MM scheme appears as a very interesting tool to efficiently perform molecular dynamics simulations of complex condensed matter systems, from solutions to nanoconfined fluids to different kind of interfaces. (paper)

A quantum-mechanics molecular-mechanics scheme for extended systems.

Science.gov (United States)

Hunt, Diego; Sanchez, Veronica M; Scherlis, Damián A

2016-08-24

We introduce and discuss a hybrid quantum-mechanics molecular-mechanics (QM-MM) approach for Car-Parrinello DFT simulations with pseudopotentials and planewaves basis, designed for the treatment of periodic systems. In this implementation the MM atoms are considered as additional QM ions having fractional charges of either sign, which provides conceptual and computational simplicity by exploiting the machinery already existing in planewave codes to deal with electrostatics in periodic boundary conditions. With this strategy, both the QM and MM regions are contained in the same supercell, which determines the periodicity for the whole system. Thus, while this method is not meant to compete with non-periodic QM-MM schemes able to handle extremely large but finite MM regions, it is shown that for periodic systems of a few hundred atoms, our approach provides substantial savings in computational times by treating classically a fraction of the particles. The performance and accuracy of the method is assessed through the study of energetic, structural, and dynamical aspects of the water dimer and of the aqueous bulk phase. Finally, the QM-MM scheme is applied to the computation of the vibrational spectra of water layers adsorbed at the TiO2 anatase (1 0 1) solid-liquid interface. This investigation suggests that the inclusion of a second monolayer of H2O molecules is sufficient to induce on the first adsorbed layer, a vibrational dynamics similar to that taking place in the presence of an aqueous environment. The present QM-MM scheme appears as a very interesting tool to efficiently perform molecular dynamics simulations of complex condensed matter systems, from solutions to nanoconfined fluids to different kind of interfaces.

Evaluating Maximum Wind Energy Exploitation in Active Distribution Networks

DEFF Research Database (Denmark)

Siano, Pierluigi; Chen, Peiyuan; Chen, Zhe

2010-01-01

The increased spreading of distributed and renewable generation requires moving towards active management of distribution networks. In this paper, in order to evaluate maximum wind energy exploitation in active distribution networks, a method based on a multi-period optimal power flow (OPF......) analysis is proposed. Active network management schemes such as coordinated voltage control, energy curtailment and power factor control are integrated in the method in order to investigate their impacts on the maximization of wind energy exploitation. Some case studies, using real data from a Danish...... distribution system, confirmed the effectiveness of the proposed method in evaluating the optimal applications of active management schemes to increase wind energy harvesting without costly network reinforcement for the connection of wind generation....

Comparison of Different Fractionation Schedules Toward a Single Fraction in High-Dose-Rate Brachytherapy as Monotherapy for Low-Risk Prostate Cancer Using 3-Dimensional Radiobiological Models

Energy Technology Data Exchange (ETDEWEB)

Mavroidis, Panayiotis, E-mail: mavroidis@uthscsa.edu [Department of Radiation Oncology, University of Texas Health Sciences Center, San Antonio, Texas (United States); Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, Stockholm (Sweden); Milickovic, Natasa [Department of Medical Physics and Engineering, Strahlenklinik, Klinikum Offenbach GmbH, Offenbach (Germany); Cruz, Wilbert F. [Department of Radiation Oncology, University of Texas Health Sciences Center, San Antonio, Texas (United States); Tselis, Nikolaos [Strahlenklinik, Klinikum Offenbach GmbH, Offenbach (Germany); Karabis, Andreas [Pi-Medical Ltd., Athens (Greece); Stathakis, Sotirios; Papanikolaou, Nikos [Department of Radiation Oncology, University of Texas Health Sciences Center, San Antonio, Texas (United States); Zamboglou, Nikolaos [Strahlenklinik, Klinikum Offenbach GmbH, Offenbach (Germany); Baltas, Dimos [Department of Medical Physics and Engineering, Strahlenklinik, Klinikum Offenbach GmbH, Offenbach (Germany); Nuclear and Particle Physics Section, Physics Department, University of Athens, Athens (Greece)

2014-01-01

Purpose: The aim of the present study was the investigation of different fractionation schemes to estimate their clinical impact. For this purpose, widely applied radiobiological models and dosimetric measures were used to associate their results with clinical findings. Methods and Materials: The dose distributions of 12 clinical high-dose-rate brachytherapy implants for prostate were evaluated in relation to different fractionation schemes. The fractionation schemes compared were: (1) 1 fraction of 20 Gy; (2) 2 fractions of 14 Gy; (3) 3 fractions of 11 Gy; and (4) 4 fractions of 9.5 Gy. The clinical effectiveness of the different fractionation schemes was estimated through the complication-free tumor control probability (P{sub +}), the biologically effective uniform dose, and the generalized equivalent uniform dose index. Results: For the different fractionation schemes, the tumor control probabilities were 98.5% in 1 × 20 Gy, 98.6% in 2 × 14 Gy, 97.5% in 3 × 11 Gy, and 97.8% in 4 × 9.5 Gy. The corresponding P{sub +} values were 88.8% in 1 × 20 Gy, 83.9% in 2 × 14 Gy, 86.0% in 3 × 11 Gy, and 82.3% in 4 × 9.5 Gy. With use of the fractionation scheme 4 × 9.5 Gy as reference, the isoeffective schemes regarding tumor control for 1, 2, and 3 fractions were 1 × 19.68 Gy, 2 × 13.75 Gy, and 3 × 11.05 Gy. The optimum fractionation schemes for 1, 2, 3, and 4 fractions were 1 × 19.16 Gy with a P{sub +} of 91.8%, 2 × 13.2 Gy with a P{sub +} of 89.6%, 3 × 10.6 Gy with a P{sub +} of 88.4%, and 4 × 9.02 Gy with a P{sub +} of 86.9%. Conclusions: Among the fractionation schemes 1 × 20 Gy, 2 × 14 Gy, 3 × 11 Gy, and 4 × 9.5 Gy, the first scheme was more effective in terms of P{sub +}. After performance of a radiobiological optimization, it was shown that a single fraction of 19.2 to 19.7 Gy (average 19.5 Gy) should produce at least the same benefit as that given by the 4 × 9.5 Gy scheme, and it should reduce the expected total complication probability by

Evaluation of the readsorption of plutonium and americium in dynamic fractionations of environmental solid samples

DEFF Research Database (Denmark)

Petersen, Roongrat; Hou, Xiaolin; Hansen, Elo Harald

2008-01-01

A dynamic extraction system exploiting sequential injection (SI) for sequential extractions incorporating a specially designed extraction column is developed to fractionate radionuclides in environmental solid samples such as soils and sediments. The extraction column can contain a large amount...... of soil sample (up to 5 g), and under optimal operational conditions it does not give rise to creation of back pressure. Attention has been placed on studies of the readsorption problems during sequential extraction using a modified Standards, Measurements and Testing (SM&T) scheme with 4-step sequential...

Impact of Vegetation Cover Fraction Parameterization schemes on Land Surface Temperature Simulation in the Tibetan Plateau

Science.gov (United States)

Lv, M.; Li, C.; Lu, H.; Yang, K.; Chen, Y.

2017-12-01

The parameterization of vegetation cover fraction (VCF) is an important component of land surface models. This paper investigates the impacts of three VCF parameterization schemes on land surface temperature (LST) simulation by the Common Land Model (CoLM) in the Tibetan Plateau (TP). The first scheme is a simple land cover (LC) based method; the second one is based on remote sensing observation (hereafter named as RNVCF) , in which multi-year climatology VCFs is derived from Moderate-resolution Imaging Spectroradiometer (MODIS) NDVI (Normalized Difference Vegetation Index); the third VCF parameterization scheme derives VCF from the LAI simulated by LSM and clump index at every model time step (hereafter named as SMVCF). Simulated land surface temperature(LST) and soil temperature by CoLM with three VCF parameterization schemes were evaluated by using satellite LST observation and in situ soil temperature observation, respectively, during the period of 2010 to 2013. The comparison against MODIS Aqua LST indicates that (1) CTL produces large biases for both four seasons in early afternoon (about 13:30, local solar time), while the mean bias in spring reach to 12.14K; (2) RNVCF and SMVCF reduce the mean bias significantly, especially in spring as such reduce is about 6.5K. Surface soil temperature observed at 5 cm depth from three soil moisture and temperature monitoring networks is also employed to assess the skill of three VCF schemes. The three networks, crossing TP from West to East, have different climate and vegetation conditions. In the Ngari network, located in the Western TP with an arid climate, there are not obvious differences among three schemes. In Naqu network, located in central TP with a semi-arid climate condition, CTL shows a severe overestimates (12.1 K), but such overestimations can be reduced by 79% by RNVCF and 87% by SMVCF. In the third humid network (Maqu in eastern TP), CoLM performs similar to Naqu. However, at both Naqu and Maqu networks

Hypo fractionated prostate treatment by volumearcotherapy modulated

International Nuclear Information System (INIS)

Clemente Gutierrez, F.; Perez Vara, C.; Prieto Villacorta, M.

2013-01-01

Several studies have been proposed over the years schemes of hypo-fractionated treatment for prostate cancer. Such schemes have been designed in order to increase local control of the disease and reduce complications. They are in addition a clear improvement from the point of view logistical and organizational for treatment centres and the patient. the hypo-fractionated treatments are possible because the ratio a/b for prostate carcinoma is comparable, and even below, the surrounding healthy tissues. This work presents the scheme adopted in our Center for the hypo-fractionated treatment of the cancer of prostate by arco therapy volumetric modulated. (Author)

Optimization of the fractionated irradiation scheme considering physical doses to tumor and organ at risk based on dose–volume histograms

Energy Technology Data Exchange (ETDEWEB)

Sugano, Yasutaka [Graduate School of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Mizuta, Masahiro [Laboratory of Advanced Data Science, Information Initiative Center, Hokkaido University, Kita-11, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0811 (Japan); Takao, Seishin; Shirato, Hiroki; Sutherland, Kenneth L. [Department of Radiation Medicine, Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Date, Hiroyuki, E-mail: date@hs.hokudai.ac.jp [Faculty of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan)

2015-11-15

Purpose: Radiotherapy of solid tumors has been performed with various fractionation regimens such as multi- and hypofractionations. However, the ability to optimize the fractionation regimen considering the physical dose distribution remains insufficient. This study aims to optimize the fractionation regimen, in which the authors propose a graphical method for selecting the optimal number of fractions (n) and dose per fraction (d) based on dose–volume histograms for tumor and normal tissues of organs around the tumor. Methods: Modified linear-quadratic models were employed to estimate the radiation effects on the tumor and an organ at risk (OAR), where the repopulation of the tumor cells and the linearity of the dose-response curve in the high dose range of the surviving fraction were considered. The minimization problem for the damage effect on the OAR was solved under the constraint that the radiation effect on the tumor is fixed by a graphical method. Here, the damage effect on the OAR was estimated based on the dose–volume histogram. Results: It was found that the optimization of fractionation scheme incorporating the dose–volume histogram is possible by employing appropriate cell surviving models. The graphical method considering the repopulation of tumor cells and a rectilinear response in the high dose range enables them to derive the optimal number of fractions and dose per fraction. For example, in the treatment of prostate cancer, the optimal fractionation was suggested to lie in the range of 8–32 fractions with a daily dose of 2.2–6.3 Gy. Conclusions: It is possible to optimize the number of fractions and dose per fraction based on the physical dose distribution (i.e., dose–volume histogram) by the graphical method considering the effects on tumor and OARs around the tumor. This method may stipulate a new guideline to optimize the fractionation regimen for physics-guided fractionation.

Design of Provider-Provisioned Website Protection Scheme against Malware Distribution

Science.gov (United States)

Yagi, Takeshi; Tanimoto, Naoto; Hariu, Takeo; Itoh, Mitsutaka

Vulnerabilities in web applications expose computer networks to security threats, and many websites are used by attackers as hopping sites to attack other websites and user terminals. These incidents prevent service providers from constructing secure networking environments. To protect websites from attacks exploiting vulnerabilities in web applications, service providers use web application firewalls (WAFs). WAFs filter accesses from attackers by using signatures, which are generated based on the exploit codes of previous attacks. However, WAFs cannot filter unknown attacks because the signatures cannot reflect new types of attacks. In service provider environments, the number of exploit codes has recently increased rapidly because of the spread of vulnerable web applications that have been developed through cloud computing. Thus, generating signatures for all exploit codes is difficult. To solve these problems, our proposed scheme detects and filters malware downloads that are sent from websites which have already received exploit codes. In addition, to collect information for detecting malware downloads, web honeypots, which automatically extract the communication records of exploit codes, are used. According to the results of experiments using a prototype, our scheme can filter attacks automatically so that service providers can provide secure and cost-effective network environments.

One Adaptive Synchronization Approach for Fractional-Order Chaotic System with Fractional-Order 1 < q < 2

Science.gov (United States)

Zhou, Ping; Bai, Rongji

2014-01-01

Based on a new stability result of equilibrium point in nonlinear fractional-order systems for fractional-order lying in 1 < q < 2, one adaptive synchronization approach is established. The adaptive synchronization for the fractional-order Lorenz chaotic system with fractional-order 1 < q < 2 is considered. Numerical simulations show the validity and feasibility of the proposed scheme. PMID:25247207

Efficient Depth Map Compression Exploiting Segmented Color Data

DEFF Research Database (Denmark)

Milani, Simone; Zanuttigh, Pietro; Zamarin, Marco

2011-01-01

performances is still an open research issue. This paper presents a novel compression scheme that exploits a segmentation of the color data to predict the shape of the different surfaces in the depth map. Then each segment is approximated with a parameterized plane. In case the approximation is sufficiently...

Estimating plume dispersion: a comparison of several sigma schemes

International Nuclear Information System (INIS)

Irwin, J.S.

1983-01-01

The lateral and vertical Gaussian plume dispersion parameters are estimated and compared with field tracer data collected at 11 sites. The dispersion parameter schemes used in this analysis include Cramer's scheme, suggested for tall stack dispersion estimates, Draxler's scheme, suggested for elevated and surface releases, Pasquill's scheme, suggested for interim use in dispersion estimates, and the Pasquill--Gifford scheme using Turner's technique for assigning stability categories. The schemes suggested by Cramer, Draxler and Pasquill estimate the dispersion parameters using onsite measurements of the vertical and lateral wind-velocity variances at the effective release height. The performances of these schemes in estimating the dispersion parameters are compared with that of the Pasquill--Gifford scheme, using the Prairie Grass and Karlsruhe data. For these two experiments, the estimates of the dispersion parameters using Draxler's scheme correlate better with the measurements than did estimates using the Pasquill--Gifford scheme. Comparison of the dispersion parameter estimates with the measurement suggests that Draxler's scheme for characterizing the dispersion results in the smallest mean fractional error in the estimated dispersion parameters and the smallest variance of the fractional errors

Rational Exploitation and Utilizing of Groundwater in Jiangsu Coastal Area

Science.gov (United States)

Kang, B.; Lin, X.

2017-12-01

Jiangsu coastal area is located in the southeast coast of China, where is a new industrial base and an important coastal and Land Resources Development Zone of China. In the areas with strong human exploitation activities, regional groundwater evolution is obviously affected by human activities. In order to solve the environmental geological problems caused by groundwater exploitation fundamentally, we must find out the forming conditions of regional groundwater hydrodynamic field, and the impact of human activities on groundwater hydrodynamic field evolution and hydrogeochemical evolition. Based on these results, scientific management and reasonable exploitation of the regional groundwater resources can be provided for the utilization. Taking the coastal area of Jiangsu as the research area, we investigate and analyze of the regional hydrogeological conditions. The numerical simulation model of groundwater flow was established according to the water power, chemical and isotopic methods, the conditions of water flow and the influence of hydrodynamic field on the water chemical field. We predict the evolution of regional groundwater dynamics under the influence of human activities and climate change and evaluate the influence of groundwater dynamic field evolution on the environmental geological problems caused by groundwater exploitation under various conditions. We get the following conclusions: Three groundwater exploitation optimal schemes were established. The groundwater salinization was taken as the primary control condition. The substitution model was proposed to model groundwater exploitation and water level changes by BP network method.Then genetic algorithm was used to solve the optimization solution. Three groundwater exploitation optimal schemes were submit to local water resource management. The first sheme was used to solve the groundwater salinization problem. The second sheme focused on dual water supply. The third sheme concerned on emergency water

A finite difference method for space fractional differential equations with variable diffusivity coefficient

KAUST Repository

Mustapha, K.

2017-06-03

Anomalous diffusion is a phenomenon that cannot be modeled accurately by second-order diffusion equations, but is better described by fractional diffusion models. The nonlocal nature of the fractional diffusion operators makes substantially more difficult the mathematical analysis of these models and the establishment of suitable numerical schemes. This paper proposes and analyzes the first finite difference method for solving {\\\\em variable-coefficient} fractional differential equations, with two-sided fractional derivatives, in one-dimensional space. The proposed scheme combines first-order forward and backward Euler methods for approximating the left-sided fractional derivative when the right-sided fractional derivative is approximated by two consecutive applications of the first-order backward Euler method. Our finite difference scheme reduces to the standard second-order central difference scheme in the absence of fractional derivatives. The existence and uniqueness of the solution for the proposed scheme are proved, and truncation errors of order $h$ are demonstrated, where $h$ denotes the maximum space step size. The numerical tests illustrate the global $O(h)$ accuracy of our scheme, except for nonsmooth cases which, as expected, have deteriorated convergence rates.

A finite difference method for space fractional differential equations with variable diffusivity coefficient

KAUST Repository

Mustapha, K.; Furati, K.; Knio, Omar; Maitre, O. Le

2017-01-01

Anomalous diffusion is a phenomenon that cannot be modeled accurately by second-order diffusion equations, but is better described by fractional diffusion models. The nonlocal nature of the fractional diffusion operators makes substantially more difficult the mathematical analysis of these models and the establishment of suitable numerical schemes. This paper proposes and analyzes the first finite difference method for solving {\\em variable-coefficient} fractional differential equations, with two-sided fractional derivatives, in one-dimensional space. The proposed scheme combines first-order forward and backward Euler methods for approximating the left-sided fractional derivative when the right-sided fractional derivative is approximated by two consecutive applications of the first-order backward Euler method. Our finite difference scheme reduces to the standard second-order central difference scheme in the absence of fractional derivatives. The existence and uniqueness of the solution for the proposed scheme are proved, and truncation errors of order $h$ are demonstrated, where $h$ denotes the maximum space step size. The numerical tests illustrate the global $O(h)$ accuracy of our scheme, except for nonsmooth cases which, as expected, have deteriorated convergence rates.

One Adaptive Synchronization Approach for Fractional-Order Chaotic System with Fractional-Order 1

Directory of Open Access Journals (Sweden)

Ping Zhou

2014-01-01

Full Text Available Based on a new stability result of equilibrium point in nonlinear fractional-order systems for fractional-order lying in 1fractional-order Lorenz chaotic system with fractional-order 1scheme.

Three-year outcomes of a once daily fractionation scheme for accelerated partial breast irradiation (APBI) using 3-D conformal radiotherapy (3D-CRT)

International Nuclear Information System (INIS)

Goyal, Sharad; Daroui, Parima; Khan, Atif J; Kearney, Thomas; Kirstein, Laurie; Haffty, Bruce G

2013-01-01

The aim of this study was to report 3-year outcomes of toxicity, cosmesis, and local control using a once daily fractionation scheme (49.95 Gy in 3.33 Gy once daily fractions) for accelerated partial breast irradiation (APBI) using three-dimensional conformal radiotherapy (3D-CRT). Between July 2008 and August 2010, women aged ≥40 years with ductal carcinoma in situ or node-negative invasive breast cancer ≤3 cm in diameter, treated with breast-conserving surgery achieving negative margins, were accrued to a prospective study. Women were treated with APBI using 3–5 photon beams, delivering 49.95 Gy over 15 once daily fractions over 3 weeks. Patients were assessed for toxicities, cosmesis, and local control rates before APBI and at specified time points. Thirty-four patients (mean age 60 years) with Tis 0 (n = 9) and T1N0 (n = 25) breast cancer were treated and followed up for an average of 39 months. Only 3% (1/34) patients experienced a grade 3 subcutaneous fibrosis and breast edema and 97% of the patients had good/excellent cosmetic outcome at 3 years. The 3-year rate of ipsilateral breast tumor recurrence (IBTR) was 0% while the rate of contralateral breast events was 6%. The 3-year disease-free survival (DFS), overall survival (OS), and breast cancer-specific survival (BCSS) was 94%, 100%, and 100%, respectively. Our novel accelerated partial breast fractionation scheme of 15 once daily fractions of 3.33 Gy (49.95 Gy total) is a remarkably well-tolerated regimen of 3D-CRT-based APBI. A larger cohort of patients is needed to further ascertain the toxicity of this accelerated partial breast regimen

On-line dynamic fractionation and automatic determination of inorganic phosphorous in environmental solid substrates exploiting sequential injection microcolumn extraction and flow injection analysi

DEFF Research Database (Denmark)

Buanuam, Janya; Miró, Manuel; Hansen, Elo Harald

2006-01-01

Sequential injection microcolumn extraction (SI-MCE) based on the implementation of a soil containing microcartridge as external reactor in a sequential injection network is, for the first time, proposed for dynamic fractionation of macronutrients in environmental solids, as exemplified by the pa......Sequential injection microcolumn extraction (SI-MCE) based on the implementation of a soil containing microcartridge as external reactor in a sequential injection network is, for the first time, proposed for dynamic fractionation of macronutrients in environmental solids, as exemplified...... by the partitioning of inorganic phosphorous in agricultural soils. The on-line fractionation method capitalises on the accurate metering and sequential exposure of the various extractants to the solid sample by application of programmable flow as precisely coordinated by a syringe pump. Three different soil phase...... associations for phosphorus, that is, exchangeable, Al- and Fe-bound and Ca-bound fractions, were elucidated by accommodation in the flow manifold of the 3 steps of the Hietjles-Litjkema (HL) scheme involving the use of 1.0 M NH4Cl, 0.1 M NaOH and 0.5 M HCl, respectively, as sequential leaching reagents...

A Comprehensive Study of Data Collection Schemes Using Mobile Sinks in Wireless Sensor Networks

Science.gov (United States)

Khan, Abdul Waheed; Abdullah, Abdul Hanan; Anisi, Mohammad Hossein; Bangash, Javed Iqbal

2014-01-01

Recently sink mobility has been exploited in numerous schemes to prolong the lifetime of wireless sensor networks (WSNs). Contrary to traditional WSNs where sensory data from sensor field is ultimately sent to a static sink, mobile sink-based approaches alleviate energy-holes issues thereby facilitating balanced energy consumption among nodes. In mobility scenarios, nodes need to keep track of the latest location of mobile sinks for data delivery. However, frequent propagation of sink topological updates undermines the energy conservation goal and therefore should be controlled. Furthermore, controlled propagation of sinks' topological updates affects the performance of routing strategies thereby increasing data delivery latency and reducing packet delivery ratios. This paper presents a taxonomy of various data collection/dissemination schemes that exploit sink mobility. Based on how sink mobility is exploited in the sensor field, we classify existing schemes into three classes, namely path constrained, path unconstrained, and controlled sink mobility-based schemes. We also organize existing schemes based on their primary goals and provide a comparative study to aid readers in selecting the appropriate scheme in accordance with their particular intended applications and network dynamics. Finally, we conclude our discussion with the identification of some unresolved issues in pursuit of data delivery to a mobile sink. PMID:24504107

Comparison of two radiotherapy schemes, conventional and fractionated, in elderly patients suffering from a locally advanced rectum cancer; Comparaison de deux schemas de radiotherapie, classique et hypofractionne, chez les patients ages atteints d'un cancer du rectum localement evolue

Energy Technology Data Exchange (ETDEWEB)

Guillerme, F.; Clavier, J.B.; Guihard, S.; Schumacher, C.; Nehme-Schuster, H.; Ben Abdelghani, M.; Noel, G. [Centre Paul-Strauss, Strasbourg (France); Kurtz, J.E.; Brigand, C. [Hopitaux universitaires, Strasbourg (France)

2011-10-15

Based on results obtained on 177 patients older than 65 and suffering from T3-4 rectum cancer, and treated either according to a conventional scheme (45 to 50,4 Gy by 1,8 to 2 Gy fractions) or according to a fractionated scheme (39 Gy by 3 Gy fractions), the authors report the comparison of these both methods in terms of toxicity, delay between end of radiotherapy and surgery), histological response, global survival. The hypo-fractionated treatment allows the treatment duration to be reduced, is therefore less constraining and seems more suitable for elderly people. Short communication

Synchronization of a new fractional-order hyperchaotic system

International Nuclear Information System (INIS)

Wu Xiangjun; Lu Hongtao; Shen Shilei

2009-01-01

In this letter, a new fractional-order hyperchaotic system is proposed. By utilizing the fractional calculus theory and computer simulations, it is found that hyperchaos exists in the new fractional-order four-dimensional system with order less than 4. The lowest order to have hyperchaos in this system is 2.88. The results are validated by the existence of two positive Lyapunov exponents. Using the pole placement technique, a nonlinear state observer is designed to synchronize a class of nonlinear fractional-order systems. The observer method is used to synchronize two identical fractional-order hyperchaotic systems. In addition, the active control technique is applied to synchronize the new fractional-order hyperchaotic system and the fractional-order Chen hyperchaotic system. The two schemes, based on the stability theory of the fractional-order system, are rather simple, theoretically rigorous and convenient to realize synchronization. They do not require the computation of the conditional Lyapunov exponents. Numerical results are performed to verify the effectiveness of the proposed synchronization schemes.

Characteristic of student’s false concessive failure on fractions concept

Science.gov (United States)

Kurniawan, H.; Sutawidjaja, A.; As’ari, A. R.; Muksar, M.

2018-03-01

False concessive failure of students is students construction failure in achieving goals, where the process is false, the results obtained is true. This failure occurs because the schemes are not connected to each other, so it cannot form a new scheme. This research is a qualitative research that aim to describe the characteristics of students' false concessive failure on fractional concepts. This fractional concept is a fraction of the same part of the whole. To be able to solve the concept of this fraction, students must possess the concept of partition, the concept of addition and the concept of multiplication of the fraction.

Stable multi-domain spectral penalty methods for fractional partial differential equations

Science.gov (United States)

Xu, Qinwu; Hesthaven, Jan S.

2014-01-01

We propose stable multi-domain spectral penalty methods suitable for solving fractional partial differential equations with fractional derivatives of any order. First, a high order discretization is proposed to approximate fractional derivatives of any order on any given grids based on orthogonal polynomials. The approximation order is analyzed and verified through numerical examples. Based on the discrete fractional derivative, we introduce stable multi-domain spectral penalty methods for solving fractional advection and diffusion equations. The equations are discretized in each sub-domain separately and the global schemes are obtained by weakly imposed boundary and interface conditions through a penalty term. Stability of the schemes are analyzed and numerical examples based on both uniform and nonuniform grids are considered to highlight the flexibility and high accuracy of the proposed schemes.

Image encryption based on a delayed fractional-order chaotic logistic system

Science.gov (United States)

Wang, Zhen; Huang, Xia; Li, Ning; Song, Xiao-Na

2012-05-01

A new image encryption scheme is proposed based on a delayed fractional-order chaotic logistic system. In the process of generating a key stream, the time-varying delay and fractional derivative are embedded in the proposed scheme to improve the security. Such a scheme is described in detail with security analyses including correlation analysis, information entropy analysis, run statistic analysis, mean-variance gray value analysis, and key sensitivity analysis. Experimental results show that the newly proposed image encryption scheme possesses high security.

Image encryption based on a delayed fractional-order chaotic logistic system

International Nuclear Information System (INIS)

Wang Zhen; Li Ning; Huang Xia; Song Xiao-Na

2012-01-01

A new image encryption scheme is proposed based on a delayed fractional-order chaotic logistic system. In the process of generating a key stream, the time-varying delay and fractional derivative are embedded in the proposed scheme to improve the security. Such a scheme is described in detail with security analyses including correlation analysis, information entropy analysis, run statistic analysis, mean-variance gray value analysis, and key sensitivity analysis. Experimental results show that the newly proposed image encryption scheme possesses high security. (general)

An Efficient Implicit FEM Scheme for Fractional-in-Space Reaction-Diffusion Equations

KAUST Repository

Burrage, Kevin

2012-01-01

Fractional differential equations are becoming increasingly used as a modelling tool for processes associated with anomalous diffusion or spatial heterogeneity. However, the presence of a fractional differential operator causes memory (time fractional) or nonlocality (space fractional) issues that impose a number of computational constraints. In this paper we develop efficient, scalable techniques for solving fractional-in-space reaction diffusion equations using the finite element method on both structured and unstructured grids via robust techniques for computing the fractional power of a matrix times a vector. Our approach is show-cased by solving the fractional Fisher and fractional Allen-Cahn reaction-diffusion equations in two and three spatial dimensions, and analyzing the speed of the traveling wave and size of the interface in terms of the fractional power of the underlying Laplacian operator. © 2012 Society for Industrial and Applied Mathematics.

A novel color image encryption scheme using fractional-order hyperchaotic system and DNA sequence operations

International Nuclear Information System (INIS)

Zhang Li-Min; Sun Ke-Hui; Liu Wen-Hao; He Shao-Bo

2017-01-01

In this paper, Adomian decomposition method (ADM) with high accuracy and fast convergence is introduced to solve the fractional-order piecewise-linear (PWL) hyperchaotic system. Based on the obtained hyperchaotic sequences, a novel color image encryption algorithm is proposed by employing a hybrid model of bidirectional circular permutation and DNA masking. In this scheme, the pixel positions of image are scrambled by circular permutation, and the pixel values are substituted by DNA sequence operations. In the DNA sequence operations, addition and substraction operations are performed according to traditional addition and subtraction in the binary, and two rounds of addition rules are used to encrypt the pixel values. The simulation results and security analysis show that the hyperchaotic map is suitable for image encryption, and the proposed encryption algorithm has good encryption effect and strong key sensitivity. It can resist brute-force attack, statistical attack, differential attack, known-plaintext, and chosen-plaintext attacks. (paper)

Recent developments in automated determinations of trace level concentrations of elements and on-line fractionations schemes exploiting the micro-sequential injection - lab-on-valve approach

DEFF Research Database (Denmark)

Hansen, Elo Harald; Miró, Manuel; Long, Xiangbao

2006-01-01

The determination of trace level concentrations of elements, such as metal species, in complex matrices by atomic absorption or emission spectrometric methods often require appropriate pretreatments comprising separation of the analyte from interfering constituents and analyte preconcentration...... are presented as based on the exploitation of micro-sequential injection (μSI-LOV) using hydrophobic as well as hydrophilic bead materials. The examples given comprise the presentation of a universal approach for SPE-assays, front-end speciation of Cr(III) and Cr(VI) in a fully automated and enclosed set...

Impulsive synchronisation of a class of fractional-order hyperchaotic systems

International Nuclear Information System (INIS)

Wang Xing-Yuan; Zhang Yong-Lei; Lin Da; Zhang Na

2011-01-01

In this paper, an impulsive synchronisation scheme for a class of fractional-order hyperchaotic systems is proposed. The sufficient conditions of a class of integral-order hyperchaotic systems' impulsive synchronisation are illustrated. Furthermore, we apply the sufficient conditions to a class of fractional-order hyperchaotic systems and well achieve impulsive synchronisation of these fractional-order hyperchaotic systems, thereby extending the applicable scope of impulsive synchronisation. Numerical simulations further demonstrate the feasibility and effectiveness of the proposed scheme. (general)

Energy harvesting schemes for building interior environment monitoring

Science.gov (United States)

Zylka, Pawel; Pociecha, Dominik

2016-11-01

A vision to supply microelectronic devices without batteries making them perpetual or extending time of service in battery-oriented mobile supply schemes is the driving force of the research related to ambient energy harvesting. Energy harnessing aims thus at extracting energy from various ambient energy "pools", which generally are cost- or powerineffective to be scaled up for full-size, power-plant energy generation schemes supplying energy in electric form. These include - but are not limited to - waste heat, electromagnetic hum, vibrations, or human-generated power in addition to traditional renewable energy resources like water flow, tidal and wind energy or sun radiation which can also be exploited at the miniature scale by energy scavengers. However, in case of taking advantage of energy harvesting strategies to power up sensors monitoring environment inside buildings adaptable energy sources are restrained to only some which additionally are limited in spatial and temporal accessibility as well as available power. The paper explores experimentally an energy harvesting scheme exploiting human kinesis applicable in indoor environment for supplying a wireless indoor micro-system, monitoring ambient air properties (pressure, humidity and temperature).

Efficient multichannel acoustic echo cancellation using constrained tap selection schemes in the subband domain

Science.gov (United States)

Desiraju, Naveen Kumar; Doclo, Simon; Wolff, Tobias

2017-12-01

Acoustic echo cancellation (AEC) is a key speech enhancement technology in speech communication and voice-enabled devices. AEC systems employ adaptive filters to estimate the acoustic echo paths between the loudspeakers and the microphone(s). In applications involving surround sound, the computational complexity of an AEC system may become demanding due to the multiple loudspeaker channels and the necessity of using long filters in reverberant environments. In order to reduce the computational complexity, the approach of partially updating the AEC filters is considered in this paper. In particular, we investigate tap selection schemes which exploit the sparsity present in the loudspeaker channels for partially updating subband AEC filters. The potential for exploiting signal sparsity across three dimensions, namely time, frequency, and channels, is analyzed. A thorough analysis of different state-of-the-art tap selection schemes is performed and insights about their limitations are gained. A novel tap selection scheme is proposed which overcomes these limitations by exploiting signal sparsity while not ignoring any filters for update in the different subbands and channels. Extensive simulation results using both artificial as well as real-world multichannel signals show that the proposed tap selection scheme outperforms state-of-the-art tap selection schemes in terms of echo cancellation performance. In addition, it yields almost identical echo cancellation performance as compared to updating all filter taps at a significantly reduced computational cost.

Cancelable remote quantum fingerprint templates protection scheme

International Nuclear Information System (INIS)

Liao Qin; Guo Ying; Huang Duan

2017-01-01

With the increasing popularity of fingerprint identification technology, its security and privacy have been paid much attention. Only the security and privacy of biological information are insured, the biological technology can be better accepted and used by the public. In this paper, we propose a novel quantum bit (qbit)-based scheme to solve the security and privacy problem existing in the traditional fingerprint identification system. By exploiting the properties of quantm mechanics, our proposed scheme, cancelable remote quantum fingerprint templates protection scheme, can achieve the unconditional security guaranteed in an information-theoretical sense. Moreover, this novel quantum scheme can invalidate most of the attacks aimed at the fingerprint identification system. In addition, the proposed scheme is applicable to the requirement of remote communication with no need to worry about its security and privacy during the transmission. This is an absolute advantage when comparing with other traditional methods. Security analysis shows that the proposed scheme can effectively ensure the communication security and the privacy of users’ information for the fingerprint identification. (paper)

Generalized Combination Complex Synchronization for Fractional-Order Chaotic Complex Systems

Directory of Open Access Journals (Sweden)

Cuimei Jiang

2015-07-01

Full Text Available Based on two fractional-order chaotic complex drive systems and one fractional-order chaotic complex response system with different dimensions, we propose generalized combination complex synchronization. In this new synchronization scheme, there are two complex scaling matrices that are non-square matrices. On the basis of the stability theory of fractional-order linear systems, we design a general controller via active control. Additionally, by virtue of two complex scaling matrices, generalized combination complex synchronization between fractional-order chaotic complex systems and real systems is investigated. Finally, three typical examples are given to demonstrate the effectiveness and feasibility of the schemes.

Adaptive multi-objective Optimization scheme for cognitive radio resource management

KAUST Repository

Alqerm, Ismail; Shihada, Basem

2014-01-01

configuration by exploiting optimization and machine learning techniques. In this paper, we propose an Adaptive Multi-objective Optimization Scheme (AMOS) for cognitive radio resource management to improve spectrum operation and network performance

A simple scheme for injection and extraction in compact rings

International Nuclear Information System (INIS)

Xu, H. S.; Huang, W. H.; Tang, C. X.

2014-01-01

There has been great interest in building compact synchrotrons for various applications, for example, inverse Compton scattering X-ray sources. However, the beam injection and extraction in compact rings require careful design for the lack of space. In this paper, we propose a simple combined injection-extraction scheme exploiting the fringe field of existing dipole magnets instead of additional septum magnets. This scheme is illustrated by using the 4.8 m ring proposed for Tsinghua Thomson scattering X-ray source as an example. Particle tracking is applied to demonstrate the validity of this scheme

Interstitial high-dose-rate brachytherapy boost: The feasibility and cosmetic outcome of a fractionated outpatient delivery scheme

International Nuclear Information System (INIS)

Manning, Matthew A.; Arthur, Douglas W.; Schmidt-Ullrich, Rupert K.; Arnfield, Mark R.; Amir, Cyrus; Zwicker, Robert D.

2000-01-01

brachytherapy provides a convenient outpatient method for boosting the lumpectomy cavity following conventional whole breast irradiation without overdosing normal tissues. The fractionation scheme of 15 Gy in 6 fractions over 3 days is well tolerated. The volume of tissue removed from the breast at lumpectomy appears to dominate cosmetic outcome in this group of patients.

Perturbation of Fractional Multi-Agent Systems in Cloud Entropy Computing

Directory of Open Access Journals (Sweden)

Rabha W. Ibrahim

2016-01-01

Full Text Available A perturbed multi-agent system is a scheme self-possessed of multiple networking agents within a location. This scheme can be used to discuss problems that are impossible or difficult for a specific agent to solve. Intelligence cloud entropy management systems involve functions, methods, procedural approaches, and algorithms. In this study, we introduce a new perturbed algorithm based on the fractional Poisson process. The discrete dynamics are suggested by using fractional entropy and fractional type Tsallis entropy. Moreover, we study the algorithm stability.

Adaptive multi-objective Optimization scheme for cognitive radio resource management

KAUST Repository

Alqerm, Ismail

2014-12-01

Cognitive Radio is an intelligent Software Defined Radio that is capable to alter its transmission parameters according to predefined objectives and wireless environment conditions. Cognitive engine is the actuator that performs radio parameters configuration by exploiting optimization and machine learning techniques. In this paper, we propose an Adaptive Multi-objective Optimization Scheme (AMOS) for cognitive radio resource management to improve spectrum operation and network performance. The optimization relies on adapting radio transmission parameters to environment conditions using constrained optimization modeling called fitness functions in an iterative manner. These functions include minimizing power consumption, Bit Error Rate, delay and interference. On the other hand, maximizing throughput and spectral efficiency. Cross-layer optimization is exploited to access environmental parameters from all TCP/IP stack layers. AMOS uses adaptive Genetic Algorithm in terms of its parameters and objective weights as the vehicle of optimization. The proposed scheme has demonstrated quick response and efficiency in three different scenarios compared to other schemes. In addition, it shows its capability to optimize the performance of TCP/IP layers as whole not only the physical layer.

Information-guided transmission in decode-and-forward relaying systems: Spatial exploitation and throughput enhancement

KAUST Repository

Yang, Yuli

2011-07-01

In addressing the issue of achieving high throughput in half-duplex relay channels, we exploit a concept of information-guided transmission for the network consisting of a source node, a destination node, and multiple half-duplex relay nodes. For further benefiting from multiple relay nodes, the relay-selection patterns are defined as the arbitrary combinations of given relay nodes. By exploiting the difference among the spatial channels states, in each relay-help transmission additional information to be forwarded is mapped onto the index of the active relay-selection pattern besides the basic information mapped onto the traditional constellation, which is forwarded by the relay node(s) in the active relay-selection pattern, so as to enhance the relay throughtput. With iterative decoding, the destination node can achieve a robust detection by decoupling the signals forwarded in different ways. We investigate the proposed scheme considering "decode-and-forward" protocol and establish its achievable transmission rate. The analytical results on capacity behaviors prove the efficiency of the proposed scheme by showing that it achieves better capacity performance than the conventional scheme. © 2011 IEEE.

Metal fractionation of atmospheric aerosols via sequential chemical extraction: a review

Energy Technology Data Exchange (ETDEWEB)

Smichowski, Patricia; Gomez, Dario [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, San Martin (Argentina); Polla, Griselda [Unidad de Actividad Fisica, Comision Nacional de Energia Atomica, San Martin (Argentina)

2005-01-01

This review surveys schemes used to sequentially chemically fractionate metals and metalloids present in airborne particulate matter. It focuses mainly on sequential chemical fractionation schemes published over the last 15 years. These schemes have been classified into five main categories: (1) based on Tessier's procedure, (2) based on Chester's procedure, (3) based on Zatka's procedure, (4) based on BCR procedure, and (5) other procedures. The operational characteristics as well as the state of the art in metal fractionation of airborne particulate matter, fly ashes and workroom aerosols, in terms of applications, optimizations and innovations, are also described. Many references to other works in this area are provided. (orig.)

A no-key-exchange secure image sharing scheme based on Shamir's three-pass cryptography protocol and the multiple-parameter fractional Fourier transform.

Science.gov (United States)

Lang, Jun

2012-01-30

In this paper, we propose a novel secure image sharing scheme based on Shamir's three-pass protocol and the multiple-parameter fractional Fourier transform (MPFRFT), which can safely exchange information with no advance distribution of either secret keys or public keys between users. The image is encrypted directly by the MPFRFT spectrum without the use of phase keys, and information can be shared by transmitting the encrypted image (or message) three times between users. Numerical simulation results are given to verify the performance of the proposed algorithm.

A joint asymmetric watermarking and image encryption scheme

Science.gov (United States)

Boato, G.; Conotter, V.; De Natale, F. G. B.; Fontanari, C.

2008-02-01

Here we introduce a novel watermarking paradigm designed to be both asymmetric, i.e., involving a private key for embedding and a public key for detection, and commutative with a suitable encryption scheme, allowing both to cipher watermarked data and to mark encrypted data without interphering with the detection process. In order to demonstrate the effectiveness of the above principles, we present an explicit example where the watermarking part, based on elementary linear algebra, and the encryption part, exploiting a secret random permutation, are integrated in a commutative scheme.

A bi-population based scheme for an explicit exploration/exploitation trade-off in dynamic environments

Science.gov (United States)

Ben-Romdhane, Hajer; Krichen, Saoussen; Alba, Enrique

2017-05-01

Optimisation in changing environments is a challenging research topic since many real-world problems are inherently dynamic. Inspired by the natural evolution process, evolutionary algorithms (EAs) are among the most successful and promising approaches that have addressed dynamic optimisation problems. However, managing the exploration/exploitation trade-off in EAs is still a prevalent issue, and this is due to the difficulties associated with the control and measurement of such a behaviour. The proposal of this paper is to achieve a balance between exploration and exploitation in an explicit manner. The idea is to use two equally sized populations: the first one performs exploration while the second one is responsible for exploitation. These tasks are alternated from one generation to the next one in a regular pattern, so as to obtain a balanced search engine. Besides, we reinforce the ability of our algorithm to quickly adapt after cnhanges by means of a memory of past solutions. Such a combination aims to restrain the premature convergence, to broaden the search area, and to speed up the optimisation. We show through computational experiments, and based on a series of dynamic problems and many performance measures, that our approach improves the performance of EAs and outperforms competing algorithms.

High-dose-rate intracavitary brachytherapy (HDR-IC) in treatment of cervical carcinoma: 5-year results and implication of increased low-grade rectal complication on initiation of an HDR-IC fractionation scheme

International Nuclear Information System (INIS)

Wang Chongjong; Wan Leung, Stephen; Chen Huichun; Sun Limin; Fang Fumin; Changchien Chanchao; Huang Engyen; Wu Jiaming; Chen Chuhnchih

1997-01-01

Purpose: To report the treatment results and rectal/bladder complications of cervical carcinoma radically treated with high-dose-rate intracavitary brachytherapy (HDR-IC). The current policy of using three-fraction scheme was examined. Methods and Materials: Between November 1987 and August 1990, 173 patients with cervical carcinoma were treated with curative-intent radiation therapy. Whole pelvic irradiation was administered with 10-MV X ray. Dose to the central cervix was 40-44 Gy in 20-22 fractions, following by pelvic wall boost 6-14 Gy in three to seven fractions with central shielding. 60 Co sources were used for HDR-IC, and 7.2 Gy was given to Point A for three applications, 1-2 weeks apart. Duration of follow-up was 5-7.8 years. Results: Twenty-eight patients (16%) developed central-regional recurrences. Overall 5-year actuarial pelvic control rate was 83%. By stage, 5-year actuarial pelvic control rates were 94%, 87%, and 72% for Stages IB + IIA, IIB + IIIA, and IIIB + IVA, respectively. Thirty-one patients (18%) developed distant metastasis. Overall 5-year actuarial survival rate was 58%. By stage, 5-year actuarial survival rates were 79%, 59%, and 41% for Stages IB + IIA, IIB + IIIA, and IIIB + IVA, respectively. Sixty-six (38%) and 19 patients (11%) developed rectal and bladder complications, respectively. For rectal complication, the overall actuarial rate was 38% at 5 years. By grade, 5-year actuarial rectal complication rates were 24%, 15%, 4%, and 3% for Grades 1-4, respectively. Overall prevalence of rectal complications was 37% and 14% at 2 and 5 years, respectively. Prevalence of low-grade rectal complication (Grades 1 and 2) was dominant at 2 years (30%), but declined to 8% at 5 years. Prevalence of high-grade, severe rectal complication (Grades 3 and 4) remained steady at 2 and 5 years (7% and 6%, respectively). Five-year actuarial bladder complication was 9%. Five-year prevalence of bladder complication was 2%. Conclusion: Using a three-fraction

Electronically Tunable Fully Integrated Fractional-Order Resonator

KAUST Repository

Tsirimokou, Georgia

2017-03-20

A fully integrated implementation of a parallel fractional-order resonator which employs together a fractional order capacitor and a fractional-order inductor is proposed in this paper. The design utilizes current-controlled Operational Transconductance Amplifiers as building blocks, designed and fabricated in AMS 0:35m CMOS process, and based on a second-order approximation of a fractional-order differentiator/ integrator magnitude optimized in the range 10Hz–700Hz. An attractive benefit of the proposed scheme is its electronic tuning capability.

Electronically Tunable Fully Integrated Fractional-Order Resonator

KAUST Repository

Tsirimokou, Georgia; Psychalinos, Costas; Elwakil, Ahmed S.; Salama, Khaled N.

2017-01-01

A fully integrated implementation of a parallel fractional-order resonator which employs together a fractional order capacitor and a fractional-order inductor is proposed in this paper. The design utilizes current-controlled Operational Transconductance Amplifiers as building blocks, designed and fabricated in AMS 0:35m CMOS process, and based on a second-order approximation of a fractional-order differentiator/ integrator magnitude optimized in the range 10Hz–700Hz. An attractive benefit of the proposed scheme is its electronic tuning capability.

Projective Synchronization of N-Dimensional Chaotic Fractional-Order Systems via Linear State Error Feedback Control

Directory of Open Access Journals (Sweden)

Baogui Xin

2012-01-01

Full Text Available Based on linear feedback control technique, a projective synchronization scheme of N-dimensional chaotic fractional-order systems is proposed, which consists of master and slave fractional-order financial systems coupled by linear state error variables. It is shown that the slave system can be projectively synchronized with the master system constructed by state transformation. Based on the stability theory of linear fractional order systems, a suitable controller for achieving synchronization is designed. The given scheme is applied to achieve projective synchronization of chaotic fractional-order financial systems. Numerical simulations are given to verify the effectiveness of the proposed projective synchronization scheme.

Use of Monomer Fraction Data in the Parametrization of Association Theories

DEFF Research Database (Denmark)

Kontogeorgis, Georgios; Tsivintzelis, Ioannis; von Solms, Nicolas

2010-01-01

the monomer fraction of hydrogen bonding compounds and their mixtures. Monomer fraction data are obtained from spectroscopic measurements and they are available for a few compounds such as pure water and alcohols as well as for some alcohol–alkane and similar mixtures. These data are useful...... “improved” model parameters can be obtained if monomer fraction data are included in the parameter estimation together with vapor pressures and liquid densities. The expression “improved” implies parameters which can represent several pure compound properties as well as monomer fraction data for pure......, liquid densities and monomer fractions of water and alcohols. The 4C scheme is the best choice for water, while for methanol there is small difference between the 2B and 3B association schemes....

On CSM classes via Chern-Fulton classes of f-schemes

OpenAIRE

Fullwood, James; Wang, Dongxu

2015-01-01

The Chern-Fulton class is a generalization of Chern class to the realm of arbitrary embeddable schemes. While Chern-Fulton classes are sensitive to non-reduced scheme structure, they are not sensitive to possible singularities of the underlying support, thus at first glance are not interesting from a singularity theory viewpoint. However, we introduce a class of formal objects which we think of as `fractional schemes', or f-schemes for short, and then show that when one broadens the domain of...

Performance comparison of binary modulation schemes for visible light communication

KAUST Repository

Park, Kihong

2015-09-11

In this paper, we investigate the power spectral density of several binary modulation schemes including variable on-off keying, variable pulse position modulation, and pulse dual slope modulation which were previously proposed for visible light communication with dimming control. We also propose a novel slope-based modulation called differential chip slope modulation (DCSM) and develop a chip-based hard-decision receiver to demodulate the resulting signal, detect the chip sequence, and decode the input bit sequence. We show that the DCSM scheme can exploit spectrum density more efficiently than the reference schemes while providing an error rate performance comparable to them. © 2015 IEEE.

Designing an Efficient Retransmission Scheme for Wireless LANs: Theory and Implementation

OpenAIRE

Koutsonikolas, Dimitrios; Wang, Chih-Chun; Hu, Y Charlie; Shroff, Ness

2010-01-01

Network coding is known to benefit the downlink retransmissions by the AP in a wireless LAN from exploiriting overhearing at the client nodes. However, designing an efficient and practical retransmission scheme remains a challange. We present an (asymptotically) optimal scheme, ECR, for reduing the downlink retransmissions by the AP in a wireless LAN from exploiting overhearing at the client nodes. The design of ECR, consisting of three components: batch-based operations, a systematic pha...

Generalized time fractional IHCP with Caputo fractional derivatives

International Nuclear Information System (INIS)

Murio, D A; MejIa, C E

2008-01-01

The numerical solution of the generalized time fractional inverse heat conduction problem (GTFIHCP) on a finite slab is investigated in the presence of measured (noisy) data when the time fractional derivative is interpreted in the sense of Caputo. The GTFIHCP involves the simultaneous identification of the heat flux and temperature transient functions at one of the boundaries of the finite slab together with the initial condition of the original direct problem from noisy Cauchy data at a discrete set of points on the opposite (active) boundary. A finite difference space marching scheme with adaptive regularization, using trigonometric mollification techniques and generalized cross validation is introduced. Error estimates for the numerical solution of the mollified problem and numerical examples are provided.

Self-match based on polling scheme for passive optical network monitoring

Science.gov (United States)

Zhang, Xuan; Guo, Hao; Jia, Xinhong; Liao, Qinghua

2018-06-01

We propose a self-match based on polling scheme for passive optical network monitoring. Each end-user is equipped with an optical matcher that exploits only the specific length patchcord and two different fiber Bragg gratings with 100% reflectivity. The simple and low-cost scheme can greatly simplify the final recognition processing of the network link status and reduce the sensitivity of the photodetector. We analyze the time-domain relation between reflected pulses and establish the calculation model to evaluate the false alarm rate. The feasibility of the proposed scheme and the validity of the time-domain relation analysis are experimentally demonstrated.

Deficiencies of the cryptography based on multiple-parameter fractional Fourier transform.

Science.gov (United States)

Ran, Qiwen; Zhang, Haiying; Zhang, Jin; Tan, Liying; Ma, Jing

2009-06-01

Methods of image encryption based on fractional Fourier transform have an incipient flaw in security. We show that the schemes have the deficiency that one group of encryption keys has many groups of keys to decrypt the encrypted image correctly for several reasons. In some schemes, many factors result in the deficiencies, such as the encryption scheme based on multiple-parameter fractional Fourier transform [Opt. Lett.33, 581 (2008)]. A modified method is proposed to avoid all the deficiencies. Security and reliability are greatly improved without increasing the complexity of the encryption process. (c) 2009 Optical Society of America.

Exploiting Multi-user Diversity and Multi-hop Diversity in Dual-hop Broadcast Channels

KAUST Repository

Zafar, Ammar

2013-05-21

We propose joint user-and-hop scheduling over dual-hop block-fading broadcast channels in order to exploit multi-user diversity gains and multi-hop diversity gains all together. To achieve this objective, the first and second hops are scheduled opportunistically based on the channel state information. The joint scheduling problem is formulated as maximizing the weighted sum of the long term achievable rates of the users under a stability constraint, which means that in the long term the rate received by the relay should equal the rate transmitted by it, in addition to power constraints. We show that this problem is equivalent to a single-hop broadcast channel by treating the source as a virtual user with an optimal weight that maintains the stability constraint. We show how to obtain the source weight either off-line based on channel statistics or on real-time based on channel measurements. Furthermore, we consider special cases including the maximum sum-rate scheduler and the proportional fair scheduler. We also show how to extend the scheme into one that allows multiple user scheduling via superposition coding with successive decoding. Numerical results demonstrate that our proposed joint scheduling scheme enlarges the rate region as compared to scheduling schemes that exploit the diversity gains partially.

Algebraic quantization, good operators and fractional quantum numbers

International Nuclear Information System (INIS)

Aldaya, V.; Calixto, M.; Guerrero, J.

1996-01-01

The problems arising when quantizing systems with periodic boundary conditions are analysed, in an algebraic (group-) quantization scheme, and the failure of the Ehrenfest theorem is clarified in terms of the already defined notion of good (and bad) operators. The analysis of constrained Heisenberg-Weyl groups according to this quantization scheme reveals the possibility for quantum operators without classical analogue and for new quantum (fractional) numbers extending those allowed for Chern classes in traditional Geometric Quantization. This study is illustrated with the examples of the free particle on the circumference and the charged particle in a homogeneous magnetic field on the torus, both examples featuring anomalous operators, non-equivalent quantization and the latter, fractional quantum numbers. These provide the rationale behind flux quantization in superconducting rings and Fractional Quantum Hall Effect, respectively. (orig.)

Cryptanalysis of a computer cryptography scheme based on a filter bank

International Nuclear Information System (INIS)

Arroyo, David; Li Chengqing; Li Shujun; Alvarez, Gonzalo

2009-01-01

This paper analyzes the security of a recently-proposed signal encryption scheme based on a filter bank. A very critical weakness of this new signal encryption procedure is exploited in order to successfully recover the associated secret key.

An Efficient Implicit FEM Scheme for Fractional-in-Space Reaction-Diffusion Equations

KAUST Repository

Burrage, Kevin; Hale, Nicholas; Kay, David

2012-01-01

Fractional differential equations are becoming increasingly used as a modelling tool for processes associated with anomalous diffusion or spatial heterogeneity. However, the presence of a fractional differential operator causes memory (time

Analytical Approach to Space- and Time-Fractional Burgers Equations

International Nuclear Information System (INIS)

Yıldırım, Ahmet; Mohyud-Din, Syed Tauseef

2010-01-01

A scheme is developed to study numerical solution of the space- and time-fractional Burgers equations under initial conditions by the homotopy analysis method. The fractional derivatives are considered in the Caputo sense. The solutions are given in the form of series with easily computable terms. Numerical solutions are calculated for the fractional Burgers equation to show the nature of solution as the fractional derivative parameter is changed

Hypo fractionated prostate treatment by volumearcotherapy modulated; Tratamiento hipofraccionado de prostata mediante arcoterapia volumetria modulada

Energy Technology Data Exchange (ETDEWEB)

Clemente Gutierrez, F.; Perez Vara, C.; Prieto Villacorta, M.

2013-07-01

Several studies have been proposed over the years schemes of hypo-fractionated treatment for prostate cancer. Such schemes have been designed in order to increase local control of the disease and reduce complications. They are in addition a clear improvement from the point of view logistical and organizational for treatment centres and the patient. the hypo-fractionated treatments are possible because the ratio a/b for prostate carcinoma is comparable, and even below, the surrounding healthy tissues. This work presents the scheme adopted in our Center for the hypo-fractionated treatment of the cancer of prostate by arco therapy volumetric modulated. (Author)

Remarks for one-dimensional fractional equations

Directory of Open Access Journals (Sweden)

Massimiliano Ferrara

2014-01-01

Full Text Available In this paper we study a class of one-dimensional Dirichlet boundary value problems involving the Caputo fractional derivatives. The existence of infinitely many solutions for this equations is obtained by exploiting a recent abstract result. Concrete examples of applications are presented.

Scheme for analysis of oily waters

Energy Technology Data Exchange (ETDEWEB)

Lysyj, I.; Rushworth, R.; Melvold, R.; Russell, E.C.

1980-01-01

A scheme is described for gross and detailed chemical characterization of oily waters. Total, suspended, and dissolved organic content and hydrocarbon levels of the sample are determined. Volatile and water-soluble fractions are characterized in greater detail. Lower aliphatic and aromatic hydrocarbons are separated from the water by nitrogen sparging and are collected in an activated carbon absorption column. They are then extracted into carbon disulfide and analyzed gas chromatographically. The water-soluble fraction is extracted into chloroform or adsorbed on Amberlite XAD type of resin. Class characterization of this fraction is performed using the HPLC procedure. GC-MS-C is used for detailed analysis. The methodology was used for studying the effectiveness of bilge and ballast water treatments.

New numerical approximation of fractional derivative with non-local and non-singular kernel: Application to chaotic models

Science.gov (United States)

Toufik, Mekkaoui; Atangana, Abdon

2017-10-01

Recently a new concept of fractional differentiation with non-local and non-singular kernel was introduced in order to extend the limitations of the conventional Riemann-Liouville and Caputo fractional derivatives. A new numerical scheme has been developed, in this paper, for the newly established fractional differentiation. We present in general the error analysis. The new numerical scheme was applied to solve linear and non-linear fractional differential equations. We do not need a predictor-corrector to have an efficient algorithm, in this method. The comparison of approximate and exact solutions leaves no doubt believing that, the new numerical scheme is very efficient and converges toward exact solution very rapidly.

The come-back of hypo fractionation?

International Nuclear Information System (INIS)

Cosset, J.M.

2005-01-01

Hypo-fractionation (i.e. the use of fewer higher fractional doses than usual) is not a new concept. It had actually been proposed in the early year of Radiotherapy by the German and Austrian specialists. In the seventy's, supported by the - wrong - hypotheses which gave birth to the NSD (Nominal Standard Dose), hypo-fractionation reappears. The consequential increase of late complications which was observed led the radiation oncologists to give up again using large doses per fraction, except for a few specific situations, such as palliative treatments. We are recently facing a new 'come-back' of hypo-fractionation, in particular for breast and prostate cancers. In the case of breast cancer, the aim is clearly to look for more 'convenience' for both the patients and the physicians, proposing shorter irradiation schedules including a lesser number of fractions. Some 'modestly' hypo-fractionated schemes have been proposed and used, without apparently altering the efficacy/toxicity ratio, but these results have been seriously questioned. As for prostate cancer, the situation is different, since in that case new radiobiological data are at the origin of the newly proposed hypo-fractionation schedules. A number of papers actually strongly suggested that the fractionation sensitivity of prostate cancer could be higher than the one of the tissues responsible for late toxicity (i.e the exact opposite of the classical dogma). Based on those data, several hypo-fractionated schemes have been proposed, with a few preliminary results looking similar to the ones obtained by the classical schedules. However, no randomized study is available so far, and a few recent radiobiological data are now questioning the new dogma of the high fractionation sensitivity of prostate cancer. For those two - frequent - cancers, it seems therefore that prudence should prevail before altering classical irradiation schedules which have proven their efficacy, while staying open to new concepts and

The LOCAL attack: Cryptanalysis of the authenticated encryption scheme ALE

DEFF Research Database (Denmark)

Khovratovich, Dmitry; Rechberger, Christian

2014-01-01

We show how to produce a forged (ciphertext, tag) pair for the scheme ALE with data and time complexity of 2102 ALE encryptions of short messages and the same number of authentication attempts. We use a differential attack based on a local collision, which exploits the availability of extracted...

Improved Side Information Generation for Distributed Video Coding by Exploiting Spatial and Temporal Correlations

Directory of Open Access Journals (Sweden)

Ye Shuiming

2009-01-01

Full Text Available Distributed video coding (DVC is a video coding paradigm allowing low complexity encoding for emerging applications such as wireless video surveillance. Side information (SI generation is a key function in the DVC decoder, and plays a key-role in determining the performance of the codec. This paper proposes an improved SI generation for DVC, which exploits both spatial and temporal correlations in the sequences. Partially decoded Wyner-Ziv (WZ frames, based on initial SI by motion compensated temporal interpolation, are exploited to improve the performance of the whole SI generation. More specifically, an enhanced temporal frame interpolation is proposed, including motion vector refinement and smoothing, optimal compensation mode selection, and a new matching criterion for motion estimation. The improved SI technique is also applied to a new hybrid spatial and temporal error concealment scheme to conceal errors in WZ frames. Simulation results show that the proposed scheme can achieve up to 1.0 dB improvement in rate distortion performance in WZ frames for video with high motion, when compared to state-of-the-art DVC. In addition, both the objective and perceptual qualities of the corrupted sequences are significantly improved by the proposed hybrid error concealment scheme, outperforming both spatial and temporal concealments alone.

A subgrid parameterization scheme for precipitation

Directory of Open Access Journals (Sweden)

S. Turner

2012-04-01

Full Text Available With increasing computing power, the horizontal resolution of numerical weather prediction (NWP models is improving and today reaches 1 to 5 km. Nevertheless, clouds and precipitation formation are still subgrid scale processes for most cloud types, such as cumulus and stratocumulus. Subgrid scale parameterizations for water vapor condensation have been in use for many years and are based on a prescribed probability density function (PDF of relative humidity spatial variability within the model grid box, thus providing a diagnosis of the cloud fraction. A similar scheme is developed and tested here. It is based on a prescribed PDF of cloud water variability and a threshold value of liquid water content for droplet collection to derive a rain fraction within the model grid. Precipitation of rainwater raises additional concerns relative to the overlap of cloud and rain fractions, however. The scheme is developed following an analysis of data collected during field campaigns in stratocumulus (DYCOMS-II and fair weather cumulus (RICO and tested in a 1-D framework against large eddy simulations of these observed cases. The new parameterization is then implemented in a 3-D NWP model with a horizontal resolution of 2.5 km to simulate real cases of precipitating cloud systems over France.

Exploiting hydrophobicity for efficient production of transmembrane helices for structure determination by NMR spectroscopy

DEFF Research Database (Denmark)

Bugge, Katrine Østergaard; Steinocher, Helena; Brooks, Andrew J.

2015-01-01

-labeled protein. In this work, we have exploited the hydrophobic nature of membrane proteins to develop a simple and efficient production scheme for isotope-labeled single-pass transmembrane domains (TMDs) with or without intrinsically disordered regions. We have evaluated the applicability and limitations...... of the strategy using seven membrane protein variants that differ in their overall hydrophobicity and length and show a recovery for suitable variants of >70%. The developed production scheme is cost-efficient and easy to implement and has the potential to facilitate an increase in the number of structures...

Physical renormalization schemes and asymptotic safety in quantum gravity

Science.gov (United States)

Falls, Kevin

2017-12-01

The methods of the renormalization group and the ɛ -expansion are applied to quantum gravity revealing the existence of an asymptotically safe fixed point in spacetime dimensions higher than two. To facilitate this, physical renormalization schemes are exploited where the renormalization group flow equations take a form which is independent of the parameterisation of the physical degrees of freedom (i.e. the gauge fixing condition and the choice of field variables). Instead the flow equation depends on the anomalous dimensions of reference observables. In the presence of spacetime boundaries we find that the required balance between the Einstein-Hilbert action and Gibbons-Hawking-York boundary term is preserved by the beta functions. Exploiting the ɛ -expansion near two dimensions we consider Einstein gravity coupled to matter. Scheme independence is generically obscured by the loop-expansion due to breaking of two-dimensional Weyl invariance. In schemes which preserve two-dimensional Weyl invariance we avoid the loop expansion and find a unique ultraviolet (UV) fixed point. At this fixed point the anomalous dimensions are large and one must resum all loop orders to obtain the critical exponents. Performing the resummation a set of universal scaling dimensions are found. These scaling dimensions show that only a finite number of matter interactions are relevant. This is a strong indication that quantum gravity is renormalizable.

Adapting IMRT delivery fraction-by-fraction to cater for variable intrafraction motion

International Nuclear Information System (INIS)

Webb, S

2008-01-01

This paper presents a technique for coping with variable intrafraction organ motion when delivering intensity-modulated radiation therapy (IMRT). The strategy is an adaptive delivery in which the fluence delivered up to a particular fraction is subtracted from the required total-course planned fluence to create an adapted residual fluence for the next fraction. This requires that the fluence already delivered can be computed, knowing the intrafraction motion during each fraction. If the adaptation is unconstrained, as would be required for perfect delivery of the planned fluence, then the individual fractional fluences would become unphysical, with both negative components and spikes. Hence it is argued that constraints must be applied; first, positivity constraints and second, constraints to limit fluence spikes. Additionally, it is shown to be helpful to constrain other quantities which are explained. The power of the strategy is that it adapts to the (potentially variable) moving geometry during each fraction. It is not a perfect delivery but it is always better than making no adaptation. The fractionated nature of radiation therapy is thus exploited to advantage. The fluence adaptation method does not require re-planning at each fraction but this imposes limitations which are stated. The fuller theory of dose adaptation is also developed for intrafraction motion. The method is complementary to other adaptive strategies recently discussed with respect to interfraction motion

A Fully Discrete Galerkin Method for a Nonlinear Space-Fractional Diffusion Equation

Directory of Open Access Journals (Sweden)

Yunying Zheng

2011-01-01

Full Text Available The spatial transport process in fractal media is generally anomalous. The space-fractional advection-diffusion equation can be used to characterize such a process. In this paper, a fully discrete scheme is given for a type of nonlinear space-fractional anomalous advection-diffusion equation. In the spatial direction, we use the finite element method, and in the temporal direction, we use the modified Crank-Nicolson approximation. Here the fractional derivative indicates the Caputo derivative. The error estimate for the fully discrete scheme is derived. And the numerical examples are also included which are in line with the theoretical analysis.

Energy-Efficient Data Gathering Scheme Based on Broadcast Transmissions in Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Soobin Lee

2013-01-01

previous works have proposed ideas that reduce the energy consumption of the network by exploiting the spatial correlation between sensed information. In this paper, we propose a distributed data compression framework that exploits the broadcasting characteristic of the wireless medium to improve energy efficiency. We analyze the performance of the proposed framework numerically and compare it with the performance of previous works using simulation. The proposed scheme performs better when the sensing information is correlated.

A higher order numerical method for time fractional partial differential equations with nonsmooth data

Science.gov (United States)

Xing, Yanyuan; Yan, Yubin

2018-03-01

Gao et al. [11] (2014) introduced a numerical scheme to approximate the Caputo fractional derivative with the convergence rate O (k 3 - α), 0 equation is sufficiently smooth, Lv and Xu [20] (2016) proved by using energy method that the corresponding numerical method for solving time fractional partial differential equation has the convergence rate O (k 3 - α), 0 equation has low regularity and in this case the numerical method fails to have the convergence rate O (k 3 - α), 0 quadratic interpolation polynomials. Based on this scheme, we introduce a time discretization scheme to approximate the time fractional partial differential equation and show by using Laplace transform methods that the time discretization scheme has the convergence rate O (k 3 - α), 0 0 for smooth and nonsmooth data in both homogeneous and inhomogeneous cases. Numerical examples are given to show that the theoretical results are consistent with the numerical results.

An Explicit Finite Difference scheme for numerical solution of fractional neutron point kinetic equation

International Nuclear Information System (INIS)

Saha Ray, S.; Patra, A.

2012-01-01

Highlights: ► In this paper fractional neutron point kinetic equation has been analyzed. ► The numerical solution for fractional neutron point kinetic equation is obtained. ► Explicit Finite Difference Method has been applied. ► Supercritical reactivity, critical reactivity and subcritical reactivity analyzed. ► Comparison between fractional and classical neutron density is presented. - Abstract: In the present article, a numerical procedure to efficiently calculate the solution for fractional point kinetics equation in nuclear reactor dynamics is investigated. The Explicit Finite Difference Method is applied to solve the fractional neutron point kinetic equation with the Grunwald–Letnikov (GL) definition (). Fractional Neutron Point Kinetic Model has been analyzed for the dynamic behavior of the neutron motion in which the relaxation time associated with a variation in the neutron flux involves a fractional order acting as exponent of the relaxation time, to obtain the best operation of a nuclear reactor dynamics. Results for neutron dynamic behavior for subcritical reactivity, supercritical reactivity and critical reactivity and also for different values of fractional order have been presented and compared with the classical neutron point kinetic (NPK) equation as well as the results obtained by the learned researchers .

Cognitive Aware Interference Mitigation Scheme for LTE Femtocells

KAUST Repository

Alqerm, Ismail

2015-04-21

Femto-cells deployment in today’s cellular networks came into practice to fulfill the increasing demand for data services. However, interference to other femto and macro-cells users remains an unresolved challenge. In this paper, we propose an interference mitigation scheme to control the cross-tier interference caused by femto-cells to the macro users and the co-tier interference among femtocells. Cognitive radio spectrum sensing capability is utilized to determine the non-occupied channels or the ones that cause minimal interference to the macro users. An awareness based channel allocation scheme is developed with the assistance of the graph-coloring algorithm to assign channels to the femto-cells base stations with power optimization, minimal interference, maximum throughput, and maximum spectrum efficiency. In addition, the scheme exploits negotiation capability to match traffic load and QoS with the channel capacity, and to maintain efficient utilization of the available channels.

On the Froehlich decomposition and the condensate fraction in He II

International Nuclear Information System (INIS)

Ghassib, H.B.; Sridhar, R.

1983-09-01

The method of extracting the Bose-Einstein condensate fraction in He II within the Froehlich decomposition scheme is revisited. A new simple formula for determining this fraction is derived. Possible experimental and theoretical implications are discussed. (author)

Broadcast Reserved Opportunity Assisted Diversity Relaying Scheme and Its Performance Evaluation

Directory of Open Access Journals (Sweden)

Xia Chen

2008-05-01

Full Text Available Relay-based transmission can over the benefits in terms of coverage extension as well as throughput improvement if compared to conventional direct transmission. In a relay enhanced cellular (REC network, where multiple mobile terminals act as relaying nodes (RNs, multiuser diversity gain can be exploited. We propose an efficient relaying scheme, referred to as Broadcast Reserved Opportunity Assisted Diversity (BROAD for the REC networks. Unlike the conventional Induced Multiuser Diversity Relaying (IMDR scheme, our scheme acquires channel quality information (CQI in which the destined node (DN sends pilots on a reserved radio resource. The BROAD scheme can significantly decrease the signaling overhead among the mobile RNs while achieving the same multiuser diversity as the conventional IMDR scheme. In addition, an alternative version of the BROAD scheme, named as A-BROAD scheme, is proposed also, in which the candidate RN(s feed back partial or full CQI to the base station (BS for further scheduling purpose. The A-BROAD scheme achieves a higher throughput than the BROAD scheme at the cost of extra signalling overhead. The theoretical analysis given in this paper demonstrates the feasibility of the schemes in terms of their multiuser diversity gains in a REC network.

Fractionation and protraction for radiotherapy of prostate carcinoma

International Nuclear Information System (INIS)

Brenner, David J.; Hall, Eric J.

1999-01-01

Purpose: To investigate whether current fractionation and brachytherapy protraction schemes for the treatment of prostatic cancer with radiation are optimal, or could be improved. Methods and Materials: We analyzed two mature data sets on radiotherapeutic tumor control for prostate cancer, one using EBRT and the other permanent seed implants, to extract the sensitivity to changes in fractionation of prostatic tumors. The standard linear-quadratic model was used for the analysis. Results: Prostatic cancers appear significantly more sensitive to changes in fractionation than most other cancers. The estimated α/β value is 1.5 Gy [0.8, 2.2]. This result is not too surprising as there is a documented relationship between cellular proliferative status and sensitivity to changes in fractionation, and prostatic tumors contain exceptionally low proportions of proliferating cells. Conclusions: High dose rate (HDR) brachytherapy would be a highly appropriate modality for treating prostate cancer. Appropriately designed HDR brachytherapy regimens would be expected to be as efficacious as low dose rate, but with added advantages of logistic convenience and more reliable dose distributions. Similarly, external beam treatments for prostate cancer can be designed using larger doses per fraction; appropriately designed hypofractionation schemes would be expected to maintain current levels of tumor control and late sequelae, but with reduced acute morbidity, together with the logistic and financial advantages of fewer numbers of fractions

Spectral analysis and multigrid preconditioners for two-dimensional space-fractional diffusion equations

Science.gov (United States)

Moghaderi, Hamid; Dehghan, Mehdi; Donatelli, Marco; Mazza, Mariarosa

2017-12-01

Fractional diffusion equations (FDEs) are a mathematical tool used for describing some special diffusion phenomena arising in many different applications like porous media and computational finance. In this paper, we focus on a two-dimensional space-FDE problem discretized by means of a second order finite difference scheme obtained as combination of the Crank-Nicolson scheme and the so-called weighted and shifted Grünwald formula. By fully exploiting the Toeplitz-like structure of the resulting linear system, we provide a detailed spectral analysis of the coefficient matrix at each time step, both in the case of constant and variable diffusion coefficients. Such a spectral analysis has a very crucial role, since it can be used for designing fast and robust iterative solvers. In particular, we employ the obtained spectral information to define a Galerkin multigrid method based on the classical linear interpolation as grid transfer operator and damped-Jacobi as smoother, and to prove the linear convergence rate of the corresponding two-grid method. The theoretical analysis suggests that the proposed grid transfer operator is strong enough for working also with the V-cycle method and the geometric multigrid. On this basis, we introduce two computationally favourable variants of the proposed multigrid method and we use them as preconditioners for Krylov methods. Several numerical results confirm that the resulting preconditioning strategies still keep a linear convergence rate.

Incentives in statutory health insurance bonus schemes - Communication as an underrated precondition of success

OpenAIRE

Viviane Scherenberg; Gerd Glaeske

2009-01-01

Aim - Bonus schemes within German statutory health insurance (GKV) use monetary incentives to promote health-conscious behaviour, particularly amongst risk groups. The idea is to exploit a latent potential for participation in money-saving preventive measures. First studies suggest that incidental effects (good risks) are more common than prevention effects. The purpose of the article is to present factors contributing to the successfulness of incentive schemes. Methods - To outline the findi...

A new color image encryption scheme using CML and a fractional-order chaotic system.

Directory of Open Access Journals (Sweden)

Xiangjun Wu

Full Text Available The chaos-based image cryptosystems have been widely investigated in recent years to provide real-time encryption and transmission. In this paper, a novel color image encryption algorithm by using coupled-map lattices (CML and a fractional-order chaotic system is proposed to enhance the security and robustness of the encryption algorithms with a permutation-diffusion structure. To make the encryption procedure more confusing and complex, an image division-shuffling process is put forward, where the plain-image is first divided into four sub-images, and then the position of the pixels in the whole image is shuffled. In order to generate initial conditions and parameters of two chaotic systems, a 280-bit long external secret key is employed. The key space analysis, various statistical analysis, information entropy analysis, differential analysis and key sensitivity analysis are introduced to test the security of the new image encryption algorithm. The cryptosystem speed is analyzed and tested as well. Experimental results confirm that, in comparison to other image encryption schemes, the new algorithm has higher security and is fast for practical image encryption. Moreover, an extensive tolerance analysis of some common image processing operations such as noise adding, cropping, JPEG compression, rotation, brightening and darkening, has been performed on the proposed image encryption technique. Corresponding results reveal that the proposed image encryption method has good robustness against some image processing operations and geometric attacks.

Consensual exploitation : the moral wrong in exploitation and legal restrictions on consensual exploitative transactions

OpenAIRE

van der Neut, Wendy

2014-01-01

This thesis is about so-­‐called consensual exploitative transactions: transactions to which all parties agree voluntarily, and which are beneficial for all parties, but which are still widely considered exploitative, and for that reason legally restricted in many countries. The thesis asks two main questions: 1. What is wrong with consensual exploitation? 2.What implications does the answer to this question have for the legal restriction of consensual transactions ...

Fractional Delayer Utilizing Hermite Interpolation with Caratheodory Representation

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Qiang DU

2018-04-01

Full Text Available Fractional delay is indispensable for many sorts of circuits and signal processing applications. Fractional delay filter (FDF utilizing Hermite interpolation with an analog differentiator is a straightforward way to delay discrete signals. This method has a low time-domain error, but a complicated sampling module than the Shannon sampling scheme. A simplified scheme, which is based on Shannon sampling and utilizing Hermite interpolation with a digital differentiator, will lead a much higher time-domain error when the signal frequency approaches the Nyquist rate. In this letter, we propose a novel fractional delayer utilizing Hermite interpolation with Caratheodory representation. The samples of differential signal are obtained by Caratheodory representation from the samples of the original signal only. So, only one sampler is needed and the sampling module is simple. Simulation results for four types of signals demonstrate that the proposed method has significantly higher interpolation accuracy than Hermite interpolation with digital differentiator.

A 3D Fractional-Order Chaotic System with Only One Stable Equilibrium and Controlling Chaos

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Shiyun Shen

2017-01-01

Full Text Available One 3D fractional-order chaotic system with only one locally asymptotically stable equilibrium is reported. To verify the chaoticity, the maximum Lyapunov exponent (MAXLE with respect to the fractional-order and chaotic attractors are obtained by numerical calculation for this system. Furthermore, by linear scalar controller consisting of a single state variable, one control scheme for stabilization of the 3D fractional-order chaotic system is suggested. The numerical simulations show the feasibility of the control scheme.

Entrapment and Enmeshment Schemes Used by Sex Traffickers.

Science.gov (United States)

Reid, Joan A

2016-09-01

Emerging research suggests that sex traffickers/pimps control the majority of trafficked girls in the United States. The youthfulness of these victims and their lack of psychosocial maturity severely diminish their ability to detect exploitative motives or withstand manipulation of traffickers. A review of 43 cases of sexually exploited girls involving non-relative traffickers and 10 semi-structured interviews with social service providers revealed numerous scripts and schemes used by sex traffickers to entrap and entangle victims including boyfriend/lover scripts, ruses involving debt bondage, friendship or faux-family scripts, threats of forced abortion or to take away children, and coerced co-offending. These findings inform potential prevention efforts and highlight the need for multi-systemic, victim-centered approaches to intervention. © The Author(s) 2014.

Numerical analysis for the fractional diffusion and fractional Buckmaster equation by the two-step Laplace Adam-Bashforth method

Science.gov (United States)

Jain, Sonal

2018-01-01

In this paper, we aim to use the alternative numerical scheme given by Gnitchogna and Atangana for solving partial differential equations with integer and non-integer differential operators. We applied this method to fractional diffusion model and fractional Buckmaster models with non-local fading memory. The method yields a powerful numerical algorithm for fractional order derivative to implement. Also we present in detail the stability analysis of the numerical method for solving the diffusion equation. This proof shows that this method is very stable and also converges very quickly to exact solution and finally some numerical simulation is presented.

The Quasi-Electron Shell Structure of the Fractional Quantum Hall Effect

Science.gov (United States)

Haxton, Wick; Haxton, Daniel

2015-04-01

The fractional quantum Hall effect (FQHE) formulated on a sphere resembles the nuclear shell model, with the desired translationally invariant states having total angular momentum zero. This property was exploited by Ginocchio and Haxton (GH) to derive a new set of scalar operators and a first-Landau-level representation of the full set of hierarchy states (fillings 1/3, 2/5, 3/7, etc.), with overlaps identical to those of Jain, who used unphysical higher Landau levels excitations followed by numerical projection. We demonstrate that the GH operators produce an appealing description of the FQHE as shells filled by non-interacting quasi-electrons, or composite fermions. These are explicitly constructed, and their planar forms are also found. The evolution of the shells and their quasi-electrons is quite unusual. The connections with electron correlations and Laughlin's variational arguments are described. We discuss how ``new states'' found experimentally at fillings such as 4/11 and 5/13 fit into this scheme. Work support in part by the US DOE Offices of Nuclear Physics and Basic Energy Sciences.

Cognitive Aware Interference Mitigation Scheme for OFDMA Femtocells

KAUST Repository

Alqerm, Ismail

2015-04-09

Femto-cells deployment in today’s cellular networks came into practice to fulfill the increasing demand for data services. It also extends the coverage in the indoor areas. However, interference to other femto and macro-cells users remains an unresolved challenge. In this paper, we propose an interference mitigation scheme to control the cross-tier interference caused by femto-cells to the macro users and the co-tier interference among femtocells. Cognitive radio spectrum sensing capability is utilized to determine the non-occupied channels or the ones that cause minimal interference to the macro users. An awareness based channel allocation scheme is developed with the assistance of the graph-coloring algorithm to assign channels to the femto-cells base stations with power optimization, minimal interference, maximum throughput, and maximum spectrum efficiency. In addition, the scheme exploits negotiation capability to match traffic load and QoS with the channel, and to maintain efficient utilization of the available channels.

Efficient Closed-Loop Schemes for MIMO-OFDM-Based WLANs

Directory of Open Access Journals (Sweden)

Jiang Yi

2006-01-01

Full Text Available The single-input single-output (SISO orthogonal frequency-division multiplexing (OFDM systems for wireless local area networks (WLAN defined by the IEEE 802.11a standard can support data rates up to 54 Mbps. In this paper, we consider deploying two transmit and two receive antennas to increase the data rate up to 108 Mbps. Applying our recent multiple-input multiple-output (MIMO transceiver designs, that is, the geometric mean decomposition (GMD and the uniform channel decomposition (UCD schemes, we propose simple and efficient closed-loop MIMO-OFDM designs for much improved performance, compared to the standard singular value decomposition (SVD based schemes as well as the open-loop V-BLAST (vertical Bell Labs layered space-time based counterparts. In the explicit feedback mode, precoder feedback is needed for the proposed schemes. We show that the overhead of feedback can be made very moderate by using a vector quantization method. In the time-division duplex (TDD mode where the channel reciprocity is exploited, our schemes turn out to be robust against the mismatch between the uplink and downlink channels. The advantages of our schemes are demonstrated via extensive numerical examples.

Distributed public key schemes secure against continual leakage

DEFF Research Database (Denmark)

Akavia, Adi; Goldwasser, Shafi; Hazay, Carmit

2012-01-01

-secure against continual memory leakage. Our DPKE scheme also implies a secure storage system on leaky devices, where a value s can be secretely stored on devices that continually leak information about their internal state to an external attacker. The devices go through a periodic refresh protocol......In this work we study distributed public key schemes secure against continual memory leakage. The secret key will be shared among two computing devices communicating over a public channel, and the decryption operation will be computed by a simple 2-party protocol between the devices. Similarly...... against continual memory leakage, under the Bilinear Decisional Diffie-Hellman and $2$-linear assumptions. Our schemes have the following properties: 1. Our DPKE and DIBE schemes tolerate leakage at all times, including during refresh. During refresh the tolerated leakage is a (1/2-o (1),1)-fraction...

Effect of low molecular fraction of thymus humoral factor on blood formation processes of irradiated mice

International Nuclear Information System (INIS)

Stolyarova, T.V.; Skobel'tsyna, E.S.; Grinberg, S.M.; Kruglikov, I.L.; Korotaev, G.K.; Tepelina, O.M.; Il'ina, T.I.

1982-01-01

The effect of low-molecular fraction of thymus humoral factor on blood formation in mice irradiated at 4 Gy was studied. It is shown that injection of low-molecular fraction of thymus hymoral factor to irradiated animals affects proliferative processes in spleen and bone marrow, however the degree of the effect depends on the injection scheme of the preparation. Application of mathematical planning methods of the experiment enables to analyze various injection schemes of low-molecular fraction of thymus humoral factor on the investigated indices. The optimal scheme of preparation injection is determined: 1st injection with the dose of 10 mkg/kg following 4 hour after irradiation, 2d injection - with the same dose in 7-21 days

Error Analysis of a Finite Element Method for the Space-Fractional Parabolic Equation

KAUST Repository

Jin, Bangti; Lazarov, Raytcho; Pasciak, Joseph; Zhou, Zhi

2014-01-01

© 2014 Society for Industrial and Applied Mathematics We consider an initial boundary value problem for a one-dimensional fractional-order parabolic equation with a space fractional derivative of Riemann-Liouville type and order α ∈ (1, 2). We study a spatial semidiscrete scheme using the standard Galerkin finite element method with piecewise linear finite elements, as well as fully discrete schemes based on the backward Euler method and the Crank-Nicolson method. Error estimates in the L2(D)- and Hα/2 (D)-norm are derived for the semidiscrete scheme and in the L2(D)-norm for the fully discrete schemes. These estimates cover both smooth and nonsmooth initial data and are expressed directly in terms of the smoothness of the initial data. Extensive numerical results are presented to illustrate the theoretical results.

Exploitation of the bloc 17: development schemes for Rosa-Lirio; L'exploitation du bloc 17: des schemas de developpement pour Rosa-Lirio

Energy Technology Data Exchange (ETDEWEB)

Legros, E.

2002-12-01

New developments are expected on the prolific bloc 17 of the Angola offshore. Among the tenth of discoveries that followed the discovery of the Girassol giant field, TotalFinaElf initially selected the Dalia field, for which engineering studies started in December 2000. However, it is still not excluded that the development of the Rosa-Lirio field will start first. This article describes the specific characteristics of this field and the solutions proposed for its exploitation. (J.S.)

Viability of exploiting L-shell fluorescence for X-ray polarimetry

Energy Technology Data Exchange (ETDEWEB)

Weisskopf, M C; Elsner, R F; Ramsey, B D [National Aeronautics and Space Administration, Huntsville, AL (USA). Space Sciences Lab.; Sutherland, P G [McMaster Univ., Hamilton, Ontario (Canada). Dept. of Physics

1985-05-15

It has been suggested that one may build an X-ray polarimeter by exploiting the polarization dependence of the angular distribution of L-shell fluorescence photons. In this paper we examine, theoretically, the sensitivity of this approach to polarimetry. We apply our calculations to several detection schemes using imaging proportional counters that would have direct application in X-ray astronomy. We find, however, that the sensitivity of this method for measuring X-ray polarization is too low to be of use for other than laboratory applications.

A blind video watermarking scheme resistant to rotation and collusion attacks

Directory of Open Access Journals (Sweden)

Amlan Karmakar

2016-04-01

Full Text Available In this paper, Discrete Cosine Transform (DCT based blind video watermarking algorithm is proposed, which is perceptually invisible and robust against rotation and collusion attacks. To make the scheme resistant against rotation, watermark is embedded within the square blocks, placed on the middle position of every luminance channel. Then Zernike moments of those square blocks are calculated. The rotation invariance property of the Complex Zernike moments is exploited to predict the rotation angle of the video at the time of extraction of watermark bits. To make the scheme robust against collusion, design of the scheme is done in such a way that the embedding blocks will vary for the successive frames of the video. A Pseudo Random Number (PRN generator and a permutation vector are used to achieve the goal. The experimental results show that the scheme is robust against conventional video attacks, rotation attack and collusion attacks.

Tegotae-based decentralised control scheme for autonomous gait transition of snake-like robots.

Science.gov (United States)

Kano, Takeshi; Yoshizawa, Ryo; Ishiguro, Akio

2017-08-04

Snakes change their locomotion patterns in response to the environment. This ability is a motivation for developing snake-like robots with highly adaptive functionality. In this study, a decentralised control scheme of snake-like robots that exhibited autonomous gait transition (i.e. the transition between concertina locomotion in narrow aisles and scaffold-based locomotion on unstructured terrains) was developed. Additionally, the control scheme was validated via simulations. A key insight revealed is that these locomotion patterns were not preprogrammed but emerged by exploiting Tegotae, a concept that describes the extent to which a perceived reaction matches a generated action. Unlike local reflexive mechanisms proposed previously, the Tegotae-based feedback mechanism enabled the robot to 'selectively' exploit environments beneficial for propulsion, and generated reasonable locomotion patterns. It is expected that the results of this study can form the basis to design robots that can work under unpredictable and unstructured environments.

Concentration and fractionation of hydrophobic organic acid constituents from natural waters by liquid chromatography

Science.gov (United States)

Thurman, E.M.; Malcolm, R.L.

1979-01-01

A scheme is presented which used adsorption chromatography with pH gradient elution and size-exclusion chromatography to concentrate and separate hydrophobic organic acids from water. A review of chromatographic processes involved in the flow scheme is also presented. Organic analytes which appear in each aqueous fraction are quantified by dissolved organic carbon analysis. Hydrophobic organic acids in a water sample are concentrated on a porous acrylic resin. These acids usually constitute approximately 30-50 percent of the dissolved organic carbon in an unpolluted water sample and are eluted with an aqueous eluent (dilute base). The concentrate is then passed through a column of polyacryloylmorpholine gel, which separates the acids into high- and low-molecular-weight fractions. The high- and low-molecular-weight eluates are reconcentrated by adsorption chromatography, then are eluted with a pH gradient into strong acids (predominately carboxylic acids) and weak acids (predominately phenolic compounds). For standard compounds and samples of unpolluted waters, the scheme fractionates humic substances into strong and weak acid fractions that are separated from the low molecular weight acids. A new method utilizing conductivity is also presented to estimate the acidic components in the methanol fraction.

Adaptive control and synchronization of a fractional-order chaotic ...

Indian Academy of Sciences (India)

Fractional order; adaptive scheme; control; synchronization. ... College of Physics and Electronics, Hunan Institute of Science and Technology, ... of Information and Communication Engineering, Hunan Institute of Science and Technology, ...

A New Fractional-Order Chaotic Complex System and Its Antisynchronization

Directory of Open Access Journals (Sweden)

Cuimei Jiang

2014-01-01

with phase portraits, bifurcation diagrams, the histories, and the largest Lyapunov exponents. And we find that chaos exists in this system with orders less than 5 by numerical simulation. Additionally, antisynchronization of different fractional-order chaotic complex systems is considered based on the stability theory of fractional-order systems. This new system and the fractional-order complex Lorenz system can achieve antisynchronization. Corresponding numerical simulations show the effectiveness and feasibility of the scheme.

A Fast Implicit Finite Difference Method for Fractional Advection-Dispersion Equations with Fractional Derivative Boundary Conditions

Directory of Open Access Journals (Sweden)

Taohua Liu

2017-01-01

Full Text Available Fractional advection-dispersion equations, as generalizations of classical integer-order advection-dispersion equations, are used to model the transport of passive tracers carried by fluid flow in a porous medium. In this paper, we develop an implicit finite difference method for fractional advection-dispersion equations with fractional derivative boundary conditions. First-order consistency, solvability, unconditional stability, and first-order convergence of the method are proven. Then, we present a fast iterative method for the implicit finite difference scheme, which only requires storage of O(K and computational cost of O(Klog⁡K. Traditionally, the Gaussian elimination method requires storage of O(K2 and computational cost of O(K3. Finally, the accuracy and efficiency of the method are checked with a numerical example.

Investigating students’ failure in fractional concept construction

Science.gov (United States)

Kurniawan, Henry; Sutawidjaja, Akbar; Rahman As’ari, Abdur; Muksar, Makbul; Setiawan, Iwan

2018-04-01

Failure is a failure to achieve goals. This failure occurs because a larger scheme integrates the schemes in mind that are related to the problem at hand. These schemes are integrated so that they are interconnected to form new structures. This new scheme structure is used to interpret the problems at hand. This research is a qualitative research done to trace student’s failure which happened in fractional concept construction. Subjects in this study as many as 2 students selected from 15 students with the consideration of these students meet the criteria that have been set into two groups that fail in solving the problem. Both groups, namely group 1 is a search group for the failure of students of S1 subject and group 2 is a search group for the failure of students of S2 subject.

Thermal stability of the aromatic fraction of Safaniya crude oil (Middle East): experimental study, kinetic scheme by molecular classes and geochemical implications; Stabilite thermique de la fraction aromatique de l'huile brute safaniya (Moyen-Orient): etude experimentale, schema cinetique par classes moleculaires et implications geochimiques

Energy Technology Data Exchange (ETDEWEB)

Al Darouich, T.

2005-07-15

The thermal evolution of reservoir oils is controlled by the kinetics of cracking reactions. The present work is concerned with the study of the thermal stability of the light aromatic components (C{sub 6}-C{sub 14}) of crude oils under geological conditions. The aim is to predict this stability through a mode l derived from laboratory pyrolyses. The light cut < 250 deg. C of Safaniya crude oil, corresponding to the C{sub 15} components, was obtained by fractionated distillation; pure aromatic fraction was then separated by liquid chromatography. Detailed molecular characterisation of the aromatic fraction was acquired using HPLC, GC and GC/MS. Then, quantified individual aromatic compounds were lumped into six molecular classes: BTXN, methyl-aromatics, alkyl-aromatics, naphthenic-aromatics, indene and sulphur - containing aromatics. Pyrolyses of the aromatic fraction were performed in gold tubes at 100 bars and different temperature/time conditions in a wide range (1 to 93%) of global conversion. Pyrolysis effluents were analysed and lumped into classes. The pyrolysis data were used to elaborate a semi - empirical kinetic scheme of 13 stoichiometric reactions for the primary and secondary cracking of the unstable classes. The scheme kinetic parameters were first estimated, and then numerically optimised, with the constraints of mass balance and hydrogen conservation. A set of pyrolysis experiments was performed at 375 deg.C under high pressures: 400, 800 and 1200 bars. Increasing slowing down in conversion rate with increasing pressure was thus observed compared to experiments at 100 bars. A slight selective effect of pressure on the different aromatic classes of the charge and on the product distribution was evidenced. The extrapolation of the kinetic model to the conditions of Elgin Field (North Sea) showed that pressure effect should shift the thermal cracking of light aromatics to higher temperatures by almost 8 deg. C. (author)

The Ethics of Exploitation

Directory of Open Access Journals (Sweden)

Paul McLaughlin

2008-11-01

Full Text Available Philosophical inquiry into exploitation has two major deficiencies to date: it assumes that exploitation is wrong by definition; and it pays too much attention to the Marxian account of exploitation. Two senses of exploitation should be distinguished: the ‘moral’ or pejorative sense and the ‘non-moral’ or ‘non-prejudicial’ sense. By demonstrating the conceptual inadequacy of exploitation as defined in the first sense, and by defining exploitation adequately in the latter sense, we seek to demonstrate the moral complexity of exploitation. We contend, moreover, that moral evaluation of exploitation is only possible once we abandon a strictly Marxian framework and attempt, in the long run, to develop an integral ethic along Godwinian lines.

Evaluation of uneven fractionation radiotherapy of cervical lymph node-metastases by linear quadratic model

International Nuclear Information System (INIS)

Sasaki, Takehito; Kamata, Rikisaburo; Urahashi, Shingo; Yamaguchi, Tetsuji.

1993-01-01

One hundred and sixty-nine cervical lymph node-metastases from head and neck squamous cell carcinomas treated with either even fractionation or uneven fractionation regimens were analyzed in the present investigation. Logistic multivariate regression analysis indicated that: type of fractionation (even vs uneven), size of metastases, T value of primary tumors, and total dose are independent variables out of 18 variables that significantly influenced the rate of tumor clearance. The data, with statistical bias corrected by the regression equation, indicated that the uneven fractionation scheme significantly improved the rate of tumor clearance for the same size of metastases, total dose, and overall time compared to the even fractionation scheme. Further analysis by a linear-quadratic cell survival model indicated that the clinical improvement by uneven fractionation might not be explained entirely by a larger dose per fraction. It is suggested that tumor cells irradiated with an uneven fractionation regimen might repopulate more slowly, or they might be either less hypoxic or redistributed in a more radiosensitive phase in the cell cycle than those irradiated with even fractionation. This conclusion is clearly not definite, but it is suitable, pending the results of further investigation. (author)

An information-guided channel-hopping scheme for block-fading channels with estimation errors

KAUST Repository

Yang, Yuli

2010-12-01

Information-guided channel-hopping technique employing multiple transmit antennas was previously proposed for supporting high data rate transmission over fading channels. This scheme achieves higher data rates than some mature schemes, such as the well-known cyclic transmit antenna selection and space-time block coding, by exploiting the independence character of multiple channels, which effectively results in having an additional information transmitting channel. Moreover, maximum likelihood decoding may be performed by simply decoupling the signals conveyed by the different mapping methods. In this paper, we investigate the achievable spectral efficiency of this scheme in the case of having channel estimation errors, with optimum pilot overhead for minimum meansquare error channel estimation, when transmitting over blockfading channels. Our numerical results further substantiate the robustness of the presented scheme, even with imperfect channel state information. ©2010 IEEE.

Adaptive nonseparable vector lifting scheme for digital holographic data compression.

Science.gov (United States)

Xing, Yafei; Kaaniche, Mounir; Pesquet-Popescu, Béatrice; Dufaux, Frédéric

2015-01-01

Holographic data play a crucial role in recent three-dimensional imaging as well as microscopic applications. As a result, huge amounts of storage capacity will be involved for this kind of data. Therefore, it becomes necessary to develop efficient hologram compression schemes for storage and transmission purposes. In this paper, we focus on the shifted distance information, obtained by the phase-shifting algorithm, where two sets of difference data need to be encoded. More precisely, a nonseparable vector lifting scheme is investigated in order to exploit the two-dimensional characteristics of the holographic contents. Simulations performed on different digital holograms have shown the effectiveness of the proposed method in terms of bitrate saving and quality of object reconstruction.

Inclusive B-meson hadroproduction in the general-mass variable-flavor-number scheme

Energy Technology Data Exchange (ETDEWEB)

Kniehl, B.A.; Kramer, G. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Schienbein, I. [Universite Joseph Fourier, Grenoble (France). Lab. de Physique Subatomique et de Cosmologie]|[CNRS/IN2P3, Inst. National Polytechnique de Grenoble (France); Spiesberger, H. [Johannes Gutenberg Univ., Mainz (Germany). Inst. fuer Physik

2007-05-15

We calculate the cross section for the inclusive hadroproduction of B mesons as a function of transverse momentum p{sub T} at next-to-leading order (NLO) in the general- mass variable-flavor-number scheme using realistic non-perturbative fragmentation functions that are obtained through a global fit to e{sup +}e{sup -} data from CERN LEP1 and SLAC SLC exploiting their universality and scaling violations. We find good agreement with recent p anti p data taken by the CDF Collaboration in run II at the Fermilab Tevatron. We also present comparisons with NLO results obtained in two other schemes. (orig.)

Function projective lag synchronization of fractional-order chaotic systems

International Nuclear Information System (INIS)

Wang Sha; Yu Yong-Guang; Wang Hu; Rahmani Ahmed

2014-01-01

Function projective lag synchronization of different structural fractional-order chaotic systems is investigated. It is shown that the slave system can be synchronized with the past states of the driver up to a scaling function matrix. According to the stability theorem of linear fractional-order systems, a nonlinear fractional-order controller is designed for the synchronization of systems with the same and different dimensions. Especially, for two different dimensional systems, the synchronization is achieved in both reduced and increased dimensions. Three kinds of numerical examples are presented to illustrate the effectiveness of the scheme. (general)

Simulating transient dynamics of the time-dependent time fractional Fokker-Planck systems

Science.gov (United States)

Kang, Yan-Mei

2016-09-01

For a physically realistic type of time-dependent time fractional Fokker-Planck (FP) equation, derived as the continuous limit of the continuous time random walk with time-modulated Boltzmann jumping weight, a semi-analytic iteration scheme based on the truncated (generalized) Fourier series is presented to simulate the resultant transient dynamics when the external time modulation is a piece-wise constant signal. At first, the iteration scheme is demonstrated with a simple time-dependent time fractional FP equation on finite interval with two absorbing boundaries, and then it is generalized to the more general time-dependent Smoluchowski-type time fractional Fokker-Planck equation. The numerical examples verify the efficiency and accuracy of the iteration method, and some novel dynamical phenomena including polarized motion orientations and periodic response death are discussed.

Fractional-Order Control of Pneumatic Position Servosystems

Directory of Open Access Journals (Sweden)

Cao Junyi

2011-01-01

Full Text Available A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cylinder and the rate of mass flow into the cylinder, the dynamic model of pneumatic position servo system is established. The fractional-order controller for pneumatic position servo and its implementation in industrial computer is designed. The experiments with fractional-order controller are carried out under various conditions, which include sine position signal with different frequency and amplitude, step position signal, and variety inertial load. The results show the effectiveness of the proposed scheme and verify their fine control performance for pneumatic position servo system.

Finite element method for time-space-fractional Schrodinger equation

Directory of Open Access Journals (Sweden)

Xiaogang Zhu

2017-07-01

Full Text Available In this article, we develop a fully discrete finite element method for the nonlinear Schrodinger equation (NLS with time- and space-fractional derivatives. The time-fractional derivative is described in Caputo's sense and the space-fractional derivative in Riesz's sense. Its stability is well derived; the convergent estimate is discussed by an orthogonal operator. We also extend the method to the two-dimensional time-space-fractional NLS and to avoid the iterative solvers at each time step, a linearized scheme is further conducted. Several numerical examples are implemented finally, which confirm the theoretical results as well as illustrate the accuracy of our methods.

Security analysis of a chaotic map-based authentication scheme for telecare medicine information systems.

Science.gov (United States)

Yau, Wei-Chuen; Phan, Raphael C-W

2013-12-01

Many authentication schemes have been proposed for telecare medicine information systems (TMIS) to ensure the privacy, integrity, and availability of patient records. These schemes are crucial for TMIS systems because otherwise patients' medical records become susceptible to tampering thus hampering diagnosis or private medical conditions of patients could be disclosed to parties who do not have a right to access such information. Very recently, Hao et al. proposed a chaotic map-based authentication scheme for telecare medicine information systems in a recent issue of Journal of Medical Systems. They claimed that the authentication scheme can withstand various attacks and it is secure to be used in TMIS. In this paper, we show that this authentication scheme is vulnerable to key-compromise impersonation attacks, off-line password guessing attacks upon compromising of a smart card, and parallel session attacks. We also exploit weaknesses in the password change phase of the scheme to mount a denial-of-service attack. Our results show that this scheme cannot be used to provide security in a telecare medicine information system.

Genomics-Assisted Exploitation of Heterosis in Perennial Ryegrass (Lolium perenne L.)

DEFF Research Database (Denmark)

Islam, Md. Shofiqul

ryegrass for the development of improved varieties. During his PhD studies, Mohammad Shofiqul Islam studied the feasibility of developing novel hybrid breeding schemes based on cytoplasmic male sterility (CMS) systems in perennial ryegrass. He successfully completed the assembly and annotation of a male......-fertile perennial ryegrass mitochondrial genome, and identified candidate genes responsible for the CMS phenotype by comparing male-fertile and male-sterile mitochondrial genomes. His findings constitute a good basis for continuing research to produce hybrid grass varieties to address the future needs......, breeding activities have been carried out to improve the population and develop synthetic varieties. This does not fully exploit the potential of heterosis, however. Hybrid breeding is an alternative strategy and provides opportunities to fully exploit the genetically available heterosis in perennial...

Screening for Proteolytic Activities in Snake Venom by Means of a Multiplexing ESI-MS Assay Scheme

NARCIS (Netherlands)

Liesener, A.; Perchuc, Anna-Maria; Schöni, Reto; Wilmer, Marianne; Karst, U.

2005-01-01

A multiplexed mass spectrometry based assay scheme for the simultaneous determination of five different substrate/product pairs was developed as a tool for screening of proteolytic activities in snake venom fractions from Bothrops moojeni. The assay scheme was employed in the functional

Carbon-13 isotopic composition of distillation fractions of some Egyptian crude oils

International Nuclear Information System (INIS)

Aly, A.I.M.; Hamza, M.S.; Abd Elsamie, S.G.

1991-01-01

13 C/ 13 C ratios were determined for some crude oil fields in the Gulf of Suez and Western Desert provinces. The crude oil was subjected to distillation at atmospheric pressure and subsequently under vacuum. Distillation fractions were collected at 25 degree C intervals. Carbon-13 content of these distillation fractions showed some differences in the degree of isotopic fractionation. The results were interpreted in view of the age of the source rocks and the degree of maturation process. The carbon-13 content of distillation fractions may be helpful in revealing petroleum mechanisms which can be exploited in exploration.4 fig

Avenues for research and technology development for industrial applications using electron beam facilities and their exploitation through BRNS schemes

International Nuclear Information System (INIS)

Markandeya, S.G.

2013-01-01

BARC has been responsible to establish indigenously designed state-of-the-art electron accelerator facilities at its Electron Beam Centre at Kharghar, Navi Mumbai. The centre offers two versatile machines namely, (i) 3 MeV, 30 kW Parallel Coupled Self Capacitance type Multiplier (Dynamitron) DC accelerator and (ii) 10 MeV, 10 kW RF Electron Linac. While these machines are being used by scientists and engineers from within DAE, there is tremendous scope for exploiting their use by researchers in the country for basic research as well as by technologists and entrepreneurs for exploiting its potential for industrial applications. However, due to lack of adequate information about the facilities and due to paucity of research funds for the academia in the country, there is always a gap which researchers seldom look forward to be filled up appropriately. The present talk will give a glimpse of some opportunities to exploit the facilities at EBC, Kharghar for variety of applications followed by a brief presentation on provisions under BRNS to carry out sponsored research activities for basic research as well as for technology development for the industrial applications. (author)

Exploiting Auto-Collimation for Real-Time Onboard Monitoring of Space Optical Camera Geometric Parameters

Science.gov (United States)

Liu, W.; Wang, H.; Liu, D.; Miu, Y.

2018-05-01

Precise geometric parameters are essential to ensure the positioning accuracy for space optical cameras. However, state-of-the-art onorbit calibration method inevitably suffers from long update cycle and poor timeliness performance. To this end, in this paper we exploit the optical auto-collimation principle and propose a real-time onboard calibration scheme for monitoring key geometric parameters. Specifically, in the proposed scheme, auto-collimation devices are first designed by installing collimated light sources, area-array CCDs, and prisms inside the satellite payload system. Through utilizing those devices, the changes in the geometric parameters are elegantly converted into changes in the spot image positions. The variation of geometric parameters can be derived via extracting and processing the spot images. An experimental platform is then set up to verify the feasibility and analyze the precision index of the proposed scheme. The experiment results demonstrate that it is feasible to apply the optical auto-collimation principle for real-time onboard monitoring.

On the formulation and numerical simulation of distributed-order fractional optimal control problems

Science.gov (United States)

Zaky, M. A.; Machado, J. A. Tenreiro

2017-11-01

In a fractional optimal control problem, the integer order derivative is replaced by a fractional order derivative. The fractional derivative embeds implicitly the time delays in an optimal control process. The order of the fractional derivative can be distributed over the unit interval, to capture delays of distinct sources. The purpose of this paper is twofold. Firstly, we derive the generalized necessary conditions for optimal control problems with dynamics described by ordinary distributed-order fractional differential equations (DFDEs). Secondly, we propose an efficient numerical scheme for solving an unconstrained convex distributed optimal control problem governed by the DFDE. We convert the problem under consideration into an optimal control problem governed by a system of DFDEs, using the pseudo-spectral method and the Jacobi-Gauss-Lobatto (J-G-L) integration formula. Next, we present the numerical solutions for a class of optimal control problems of systems governed by DFDEs. The convergence of the proposed method is graphically analyzed showing that the proposed scheme is a good tool for the simulation of distributed control problems governed by DFDEs.

Numerical solution for multi-term fractional (arbitrary) orders differential equations

OpenAIRE

El-Sayed, A. M. A.; El-Mesiry, A. E. M.; El-Saka, H. A. A.

2004-01-01

Our main concern here is to give a numerical scheme to solve a nonlinear multi-term fractional (arbitrary) orders differential equation. Some results concerning the existence and uniqueness have been also obtained.

Tunable fractional-order Fourier transformer

International Nuclear Information System (INIS)

Malyutin, A A

2006-01-01

A fractional two-dimensional Fourier transformer whose orders are tuned by means of optical quadrupoles is described. It is shown that in the optical scheme considered, the Fourier-transform order a element of [0,1] in one of the mutually orthogonal planes corresponds to the transform order (2-a) in another plane, i.e., to inversion and inverse Fourier transform of the order a. (laser modes and beams)

A Novel Deterministic Secure Quantum Communication Scheme with Einstein—Podolsky—Rosen Pairs and Single Photons

International Nuclear Information System (INIS)

Wang Chao; Liu Jian-Wei; Liu Xiao; Shang Tao

2013-01-01

A novel deterministic secure quantum communication (DSQC) scheme is presented based on Einstein-Podolsky-Rosen (EPR) pairs and single photons in this study. In this scheme, the secret message can be encoded directly on the first particles of the prepared Bell states by simple unitary operations and decoded by performing the Bell-basis measurement after the additional classic information is exchanged. In addition, the strategy with two-step transmission of quantum data blocks and the technique of decoy-particle checking both are exploited to guarantee the security of the communication. Compared with some previous DSQC schemes, this scheme not only has a higher resource capacity, intrinsic efficiency and total efficiency, but also is more realizable in practical applications. Security analysis shows that the proposed scheme is unconditionally secure against various attacks over an ideal quantum channel and still conditionally robust over a noisy and lossy quantum channel. (general)

On the viability of exploiting L-shell fluorescence for X-ray polarimetry

Energy Technology Data Exchange (ETDEWEB)

Weisskopf, M C; Elsner, R F; Ramsey, B D; Sutherland, P G

1985-05-15

It has been suggested that one may build an X-ray polarimeter by exploiting the polarization dependence of the angular distribution of L-shell fluorescence photons. In this paper we examine, theoretically, the sensitivity of this approach to polarimetry. We apply our calculations to several detection schemes using imaging proportional counters that would have direct application in X-ray astronomy. We find, however, that the sensitivity of this method for measuring X-ray polarization is too low to be of use for other than laboratory applications. (orig.).

Efficient coding schemes with power allocation using space-time-frequency spreading

Institute of Scientific and Technical Information of China (English)

Jiang Haining; Luo Hanwen; Tian Jifeng; Song Wentao; Liu Xingzhao

2006-01-01

An efficient space-time-frequency (STF) coding strategy for multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) systems is presented for high bit rate data transmission over frequency selective fading channels. The proposed scheme is a new approach to space-time-frequency coded OFDM (COFDM) that combines OFDM with space-time coding, linear precoding and adaptive power allocation to provide higher quality of transmission in terms of the bit error rate performance and power efficiency. In addition to exploiting the maximum diversity gain in frequency, time and space, the proposed scheme enjoys high coding advantages and low-complexity decoding. The significant performance improvement of our design is confirmed by corroborating numerical simulations.

Study of the AC machines winding having fractional q

Science.gov (United States)

Bespalov, V. Y.; Sidorov, A. O.

2018-02-01

The winding schemes with a fractional numbers of slots per pole and phase q have been known and used for a long time. However, in the literature on the low-noise machines design there are not recommended to use. Nevertheless, fractional q windings have been realized in many applications of special AC electrical machines, allowing to improve their performance, including vibroacoustic one. This paper deals with harmonic analysis of windings having integer and fractional q in permanent magnet synchronous motors, a comparison of their characteristics is performed, frequencies of subharmonics are revealed. Optimal winding pitch design is found giving reduce the amplitudes of subharmonics. Distribution factors for subharmonics, fractional and high-order harmonics are calculated, results analysis is represented, allowing for giving recommendations how to calculate distribution factors for different harmonics when q is fractional.

Compress compound images in H.264/MPGE-4 AVC by exploiting spatial correlation.

Science.gov (United States)

Lan, Cuiling; Shi, Guangming; Wu, Feng

2010-04-01

Compound images are a combination of text, graphics and natural image. They present strong anisotropic features, especially on the text and graphics parts. These anisotropic features often render conventional compression inefficient. Thus, this paper proposes a novel coding scheme from the H.264 intraframe coding. In the scheme, two new intramodes are developed to better exploit spatial correlation in compound images. The first is the residual scalar quantization (RSQ) mode, where intrapredicted residues are directly quantized and coded without transform. The second is the base colors and index map (BCIM) mode that can be viewed as an adaptive color quantization. In this mode, an image block is represented by several representative colors, referred to as base colors, and an index map to compress. Every block selects its coding mode from two new modes and the previous intramodes in H.264 by rate-distortion optimization (RDO). Experimental results show that the proposed scheme improves the coding efficiency even more than 10 dB at most bit rates for compound images and keeps a comparable efficient performance to H.264 for natural images.

A scheme comparison of Autler-Townes based slow light in inhomogeneously broadened quantum dot media

DEFF Research Database (Denmark)

Hansen, Per Lunnemann; Mørk, Jesper

2010-01-01

We propose a method to achieve significant optical signal delays exploiting the effect of Autler–Townes splitting (ATS) in an inhomogeneously broadened quantum dot medium. The absorption and slowdown effects are compared for three schemes i.e., Ξ, V, and Λ, corresponding to different excitation c...

Stability estimates for solution of IBVP to fractional parabolic differential and difference equations

Science.gov (United States)

Ashyralyev, Allaberen; Cakir, Zafer

2016-08-01

In this work, we investigate initial-boundary value problems for fractional parabolic equations with the Neumann boundary condition. Stability estimates for the solution of this problem are established. Difference schemes for approximate solution of initial-boundary value problem are constructed. Furthermore, we give theorem on coercive stability estimates for the solution of the difference schemes.

The fractional-order modeling and synchronization of electrically coupled neuron systems

KAUST Repository

Moaddy, K.

2012-11-01

In this paper, we generalize the integer-order cable model of the neuron system into the fractional-order domain, where the long memory dependence of the fractional derivative can be a better fit for the neuron response. Furthermore, the chaotic synchronization with a gap junction of two or multi-coupled-neurons of fractional-order are discussed. The circuit model, fractional-order state equations and the numerical technique are introduced in this paper for individual and multiple coupled neuron systems with different fractional-orders. Various examples are introduced with different fractional orders using the non-standard finite difference scheme together with the Grünwald-Letnikov discretization process which is easily implemented and reliably accurate. © 2011 Elsevier Ltd. All rights reserved.

The fractional-order modeling and synchronization of electrically coupled neuron systems

KAUST Repository

Moaddy, K.; Radwan, Ahmed G.; Salama, Khaled N.; Momani, Shaher M.; Hashim, Ishak

2012-01-01

In this paper, we generalize the integer-order cable model of the neuron system into the fractional-order domain, where the long memory dependence of the fractional derivative can be a better fit for the neuron response. Furthermore, the chaotic synchronization with a gap junction of two or multi-coupled-neurons of fractional-order are discussed. The circuit model, fractional-order state equations and the numerical technique are introduced in this paper for individual and multiple coupled neuron systems with different fractional-orders. Various examples are introduced with different fractional orders using the non-standard finite difference scheme together with the Grünwald-Letnikov discretization process which is easily implemented and reliably accurate. © 2011 Elsevier Ltd. All rights reserved.

The Galerkin finite element method for a multi-term time-fractional diffusion equation

KAUST Repository

Jin, Bangti

2015-01-01

© 2014 The Authors. We consider the initial/boundary value problem for a diffusion equation involving multiple time-fractional derivatives on a bounded convex polyhedral domain. We analyze a space semidiscrete scheme based on the standard Galerkin finite element method using continuous piecewise linear functions. Nearly optimal error estimates for both cases of initial data and inhomogeneous term are derived, which cover both smooth and nonsmooth data. Further we develop a fully discrete scheme based on a finite difference discretization of the time-fractional derivatives, and discuss its stability and error estimate. Extensive numerical experiments for one- and two-dimensional problems confirm the theoretical convergence rates.

Characterization and blood coagulation evaluation of the water-soluble chitooligosaccharides prepared by a facile fractionation method.

Science.gov (United States)

Lin, Chia-Wen; Lin, Jui-Che

2003-01-01

Water-soluble chitooligosaccharides have been reported to have specific biological activities. In this study, the chitosan samples with different degree of acetylation were used separately to prepare chitooligosaccharide (COS) and highly deacetylated chitooligosaccharide (HDCOS) through the nitrous acid depolymerization. Rather than using the conventional fractionation schemes commonly employed, such as dialysis and ultrafiltration which require a large amount of deionized water as well as a fair long dwell time, an unique fractionation scheme is explored to recover and desalt these nitrous-acid depolymerized chitosan with different molecular weights. This fractionation scheme is based on the differential solubility variation of depolymerized products within the aqueous solutions that contain various ratios of methanol. It was noted that chitosan with different molecular weight can be successfully recovered and fractionated with methanol added sequentially up to a volume of four times of original depolmerized product. In addition, chemical characterization of the fractionated water-soluble COS and HDCOS by 1H NMR spectroscopy and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) indicated that the chitosan depolymerization reaction is greatly influenced by the degree of acetylation of the parental chitosan reactant. Moreover, the modified whole blood clotting time assay and the platelet coagulation test suggested that the 1:2 fractionated water-soluble COS and HDCOS obtained are much less procoagulant than their parental chitosan compound and can be of use in biomedical applications in which blood coagulation is not desired.

Hacking the art of exploitation

CERN Document Server

Erickson, Jon

2003-01-01

A comprehensive introduction to the techniques of exploitation and creative problem-solving methods commonly referred to as "hacking," Hacking: The Art of Exploitation is for both technical and non-technical people who are interested in computer security. It shows how hackers exploit programs and write exploits, instead of just how to run other people's exploits. Unlike many so-called hacking books, this book explains the technical aspects of hacking, including stack based overflows, heap based overflows, string exploits, return-into-libc, shellcode, and cryptographic attacks on 802.11b.

A Hybrid Data Compression Scheme for Improved VNC

Directory of Open Access Journals (Sweden)

Xiaozheng (Jane Zhang

2007-04-01

Full Text Available Virtual Network Computing (VNC has emerged as a promising technology in distributed computing environment since its invention in the late nineties. Successful application of VNC requires rapid data transfer from one machine to another over a TCP/IP network connection. However transfer of screen data consumes much network bandwidth and current data encoding schemes for VNC are far from being ideal. This paper seeks to improve screen data compression techniques to enable VNC over slow connections and present a reasonable speed and image quality. In this paper, a hybrid technique is proposed for improving coding efficiency. The algorithm first divides a screen image into pre-defined regions and applies encoding schemes to each area according to the region characteristics. Second, correlation of screen data in consecutive frames is exploited where multiple occurrences of similar image contents are detected. The improved results are demonstrated in a dynamic environment with various screen image types and desktop manipulation.

A novel adaptive-impulsive synchronization of fractional-order chaotic systems

International Nuclear Information System (INIS)

Andrew, Leung Y. T.; Xian-Feng, Li; Yan-Dong, Chu; Hui, Zhang

2015-01-01

A novel adaptive–impulsive scheme is proposed for synchronizing fractional-order chaotic systems without the necessity of knowing the attractors’ bounds in priori. The nonlinear functions in these systems are supposed to satisfy local Lipschitz conditions but which are estimated with adaptive laws. The novelty is that the combination of adaptive control and impulsive control offers a control strategy gathering the advantages of both. In order to guarantee the convergence is no less than an expected exponential rate, a combined feedback strength design is created such that the symmetric axis can shift freely according to the updated transient feedback strength. All of the unknown Lipschitz constants are also updated exponentially in the meantime of achieving synchronization. Two different fractional-order chaotic systems are employed to demonstrate the effectiveness of the novel adaptive–impulsive control scheme. (paper)

Hypo fractionated radiotherapy in advanced lung cancer

International Nuclear Information System (INIS)

Andrade Carvalho, Heloisa de; Saito, Newton Heitetsu; Gomes, Herbeni Cardoso; Aguilar, Patricia Bailao; Nadalin, Wladimir

1996-01-01

Patients with advanced lung cancers have bad prognosis and, many times, are submitted to prolonged and not always efficient treatments. We present a study where 51 patients were treated with hypo fractionated radiotherapy, based on two distinct schemes, according to the performance status and social conditions of each patient: continuous treatment: 30 Gy, 10 fractions of 3 Gy, 5 days/week (37 cases); weekly treatment: 30 Gy, 6 fractions of 5 Gy, once a week (14 cases). Symptoms relief and impact in survival were evaluated. In both groups, we observed improvement of symptoms in about 70% of the occurrences with a medium survival of three months. We conclude that hypo fractionation is an effective palliative treatment for lung cancers, in patients with short life-expectancy and must be considered as a option in advanced cases, in patients with short life-expectancy that deserve some kind of treatment. (author). 37 refs., 2 tabs

Additive operator-difference schemes splitting schemes

CERN Document Server

Vabishchevich, Petr N

2013-01-01

Applied mathematical modeling isconcerned with solving unsteady problems. This bookshows how toconstruct additive difference schemes to solve approximately unsteady multi-dimensional problems for PDEs. Two classes of schemes are highlighted: methods of splitting with respect to spatial variables (alternating direction methods) and schemes of splitting into physical processes. Also regionally additive schemes (domain decomposition methods)and unconditionally stable additive schemes of multi-component splitting are considered for evolutionary equations of first and second order as well as for sy

Neural Computation Scheme of Compound Control: Tacit Learning for Bipedal Locomotion

Science.gov (United States)

Shimoda, Shingo; Kimura, Hidenori

The growing need for controlling complex behaviors of versatile robots working in unpredictable environment has revealed the fundamental limitation of model-based control strategy that requires precise models of robots and environments before their operations. This difficulty is fundamental and has the same root with the well-known frame problem in artificial intelligence. It has been a central long standing issue in advanced robotics, as well as machine intelligence, to find a prospective clue to attack this fundamental difficulty. The general consensus shared by many leading researchers in the related field is that the body plays an important role in acquiring intelligence that can conquer unknowns. In particular, purposeful behaviors emerge during body-environment interactions with the help of an appropriately organized neural computational scheme that can exploit what the environment can afford. Along this line, we propose a new scheme of neural computation based on compound control which represents a typical feature of biological controls. This scheme is based on classical neuron models with local rules that can create macroscopic purposeful behaviors. This scheme is applied to a bipedal robot and generates the rhythm of walking without any model of robot dynamics and environments.

Exploitation of Labour and Exploitation of Commodities: a “New Interpretation”

OpenAIRE

Veneziani, Roberto; Yoshihara, Naoki

2011-01-01

In the standard Okishio-Morishima approach, the existence of profits is proved to be equivalent to the exploitation of labour. Yet, it can also be proved that the existence of profits is equivalent to the ‘exploitation’ of any good. Labour and commodity exploitation are just different numerical representations of the productiveness of the economy. This paper presents an alternative approach to exploitation theory which is related to the New Interpretation (Duménil 1980; Foley 1982). In this a...

Improved Fractional Order VSS Inc-Cond MPPT Algorithm for Photovoltaic Scheme

Directory of Open Access Journals (Sweden)

R. Arulmurugan

2014-01-01

Full Text Available Nowadays a hot topic among the research community is the harnessing energy from the free sunlight which is abundant and pollution-free. The availability of cheap solar photovoltaic (PV modules has to harvest solar energy with better efficiency. The nature of solar modules is nonlinear and therefore the proper impedance matching is essential. The proper impedance matching ensures the extraction of the maximum power from solar PV module. Maximum power point tracking (MPPT algorithm is acting as a significant part in solar power generating system because it varies in the output power from a PV generating set for various climatic conditions. This paper suggested a new improved work for MPPT of PV energy system by using the optimized novel improved fractional order variable step size (FOVSS incremental conductance (Inc-Cond algorithm. The new proposed controller combines the merits of both improved fractional order (FO and variable step size (VSS Inc-Cond which is well suitable for design control and execution. The suggested controller results in attaining the desired transient reaction under changing operating points. MATLAB simulation effort shows MPPT controller and a DC to DC Luo converter feeding a battery load is achieved. The laboratory experimental results demonstrate that the new proposed MPPT controller in the photovoltaic generating system is valid.

Information-Aided Smart Schemes for Vehicle Flow Detection Enhancements of Traffic Microwave Radar Detectors

Directory of Open Access Journals (Sweden)

Tan-Jan Ho

2016-07-01

Full Text Available For satisfactory traffic management of an intelligent transport system, it is vital that traffic microwave radar detectors (TMRDs can provide real-time traffic information with high accuracy. In this study, we develop several information-aided smart schemes for traffic detection improvements of TMRDs in multiple-lane environments. Specifically, we select appropriate thresholds not only for removing noise from fast Fourier transforms (FFTs of regional lane contexts but also for reducing FFT side lobes within each lane. The resulting FFTs of reflected vehicle signals and those of clutter are distinguishable. We exploit FFT and lane-/or time stamp-related information for developing smart schemes, which mitigate adverse effects of lane-crossing FFT side lobes of a vehicle signal. As such, the proposed schemes can enhance the detection accuracy of both lane vehicle flow and directional traffic volume. On-site experimental results demonstrate the advantages and feasibility of the proposed methods, and suggest the best smart scheme.

A Class of time-fractional hemivariational inequalities with application to frictional contact problem

Science.gov (United States)

Zeng, Shengda; Migórski, Stanisław

2018-03-01

In this paper a class of elliptic hemivariational inequalities involving the time-fractional order integral operator is investigated. Exploiting the Rothe method and using the surjectivity of multivalued pseudomonotone operators, a result on existence of solution to the problem is established. Then, this abstract result is applied to provide a theorem on the weak solvability of a fractional viscoelastic contact problem. The process is quasistatic and the constitutive relation is modeled with the fractional Kelvin-Voigt law. The friction and contact conditions are described by the Clarke generalized gradient of nonconvex and nonsmooth functionals. The variational formulation of this problem leads to a fractional hemivariational inequality.

Exploitation and disadvantage

NARCIS (Netherlands)

Ferguson, B.

2016-01-01

According to some accounts of exploitation, most notably Ruth Sample's (2003) degradation-based account and Robert Goodin's (1987) vulnerability-based account, exploitation occurs when an advantaged party fails to constrain their advantage in light of another's disadvantage, regardless of the cause

Spatial and temporal accuracy of asynchrony-tolerant finite difference schemes for partial differential equations at extreme scales

Science.gov (United States)

Kumari, Komal; Donzis, Diego

2017-11-01

Highly resolved computational simulations on massively parallel machines are critical in understanding the physics of a vast number of complex phenomena in nature governed by partial differential equations. Simulations at extreme levels of parallelism present many challenges with communication between processing elements (PEs) being a major bottleneck. In order to fully exploit the computational power of exascale machines one needs to devise numerical schemes that relax global synchronizations across PEs. This asynchronous computations, however, have a degrading effect on the accuracy of standard numerical schemes.We have developed asynchrony-tolerant (AT) schemes that maintain order of accuracy despite relaxed communications. We show, analytically and numerically, that these schemes retain their numerical properties with multi-step higher order temporal Runge-Kutta schemes. We also show that for a range of optimized parameters,the computation time and error for AT schemes is less than their synchronous counterpart. Stability of the AT schemes which depends upon history and random nature of delays, are also discussed. Support from NSF is gratefully acknowledged.

An analytical model to calculate absorbed fractions for internal dosimetry with alpha, beta and gamma emitters

OpenAIRE

Amato, Ernesto; Italiano, Antonio; Baldari, Sergio

2014-01-01

We developed a general model for the calculation of absorbed fractions in ellipsoidal volumes of soft tissue uniformly filled with alpha, beta and gamma emitting radionuclides. The approach exploited Monte Carlo simulations with the Geant4 code to determine absorbed fractions in ellipsoids characterized by a wide range of dimensions and ellipticities, for monoenergetic emissions of each radiation type. The so-obtained absorbed fractions were put in an analytical relationship with the 'general...

Exploiting GPUs in Virtual Machine for BioCloud

Science.gov (United States)

Jo, Heeseung; Jeong, Jinkyu; Lee, Myoungho; Choi, Dong Hoon

2013-01-01

Recently, biological applications start to be reimplemented into the applications which exploit many cores of GPUs for better computation performance. Therefore, by providing virtualized GPUs to VMs in cloud computing environment, many biological applications will willingly move into cloud environment to enhance their computation performance and utilize infinite cloud computing resource while reducing expenses for computations. In this paper, we propose a BioCloud system architecture that enables VMs to use GPUs in cloud environment. Because much of the previous research has focused on the sharing mechanism of GPUs among VMs, they cannot achieve enough performance for biological applications of which computation throughput is more crucial rather than sharing. The proposed system exploits the pass-through mode of PCI express (PCI-E) channel. By making each VM be able to access underlying GPUs directly, applications can show almost the same performance as when those are in native environment. In addition, our scheme multiplexes GPUs by using hot plug-in/out device features of PCI-E channel. By adding or removing GPUs in each VM in on-demand manner, VMs in the same physical host can time-share their GPUs. We implemented the proposed system using the Xen VMM and NVIDIA GPUs and showed that our prototype is highly effective for biological GPU applications in cloud environment. PMID:23710465

Exploiting GPUs in Virtual Machine for BioCloud

Directory of Open Access Journals (Sweden)

Heeseung Jo

2013-01-01

Full Text Available Recently, biological applications start to be reimplemented into the applications which exploit many cores of GPUs for better computation performance. Therefore, by providing virtualized GPUs to VMs in cloud computing environment, many biological applications will willingly move into cloud environment to enhance their computation performance and utilize infinite cloud computing resource while reducing expenses for computations. In this paper, we propose a BioCloud system architecture that enables VMs to use GPUs in cloud environment. Because much of the previous research has focused on the sharing mechanism of GPUs among VMs, they cannot achieve enough performance for biological applications of which computation throughput is more crucial rather than sharing. The proposed system exploits the pass-through mode of PCI express (PCI-E channel. By making each VM be able to access underlying GPUs directly, applications can show almost the same performance as when those are in native environment. In addition, our scheme multiplexes GPUs by using hot plug-in/out device features of PCI-E channel. By adding or removing GPUs in each VM in on-demand manner, VMs in the same physical host can time-share their GPUs. We implemented the proposed system using the Xen VMM and NVIDIA GPUs and showed that our prototype is highly effective for biological GPU applications in cloud environment.

Exploiting GPUs in virtual machine for BioCloud.

Science.gov (United States)

Jo, Heeseung; Jeong, Jinkyu; Lee, Myoungho; Choi, Dong Hoon

2013-01-01

Recently, biological applications start to be reimplemented into the applications which exploit many cores of GPUs for better computation performance. Therefore, by providing virtualized GPUs to VMs in cloud computing environment, many biological applications will willingly move into cloud environment to enhance their computation performance and utilize infinite cloud computing resource while reducing expenses for computations. In this paper, we propose a BioCloud system architecture that enables VMs to use GPUs in cloud environment. Because much of the previous research has focused on the sharing mechanism of GPUs among VMs, they cannot achieve enough performance for biological applications of which computation throughput is more crucial rather than sharing. The proposed system exploits the pass-through mode of PCI express (PCI-E) channel. By making each VM be able to access underlying GPUs directly, applications can show almost the same performance as when those are in native environment. In addition, our scheme multiplexes GPUs by using hot plug-in/out device features of PCI-E channel. By adding or removing GPUs in each VM in on-demand manner, VMs in the same physical host can time-share their GPUs. We implemented the proposed system using the Xen VMM and NVIDIA GPUs and showed that our prototype is highly effective for biological GPU applications in cloud environment.

Learning Metasploit exploitation and development

CERN Document Server

Balapure, Aditya

2013-01-01

A practical, hands-on tutorial with step-by-step instructions. The book will follow a smooth and easy-to-follow tutorial approach, covering the essentials and then showing the readers how to write more sophisticated exploits.This book targets exploit developers, vulnerability analysts and researchers, network administrators, and ethical hackers looking to gain advanced knowledge in exploitation development and identifying vulnerabilities. The primary goal is to take readers wishing to get into more advanced exploitation discovery and reaching the next level.Prior experience exploiting basic st

Programming scheme based optimization of hybrid 4T-2R OxRAM NVSRAM

Science.gov (United States)

Majumdar, Swatilekha; Kingra, Sandeep Kaur; Suri, Manan

2017-09-01

In this paper, we present a novel single-cycle programming scheme for 4T-2R NVSRAM, exploiting pulse engineered input signals. OxRAM devices based on 3 nm thick bi-layer active switching oxide and 90 nm CMOS technology node were used for all simulations. The cell design is implemented for real-time non-volatility rather than last-bit, or power-down non-volatility. Detailed analysis of the proposed single-cycle, parallel RRAM device programming scheme is presented in comparison to the two-cycle sequential RRAM programming used for similar 4T-2R NVSRAM bit-cells. The proposed single-cycle programming scheme coupled with the 4T-2R architecture leads to several benefits such as- possibility of unconventional transistor sizing, 50% lower latency, 20% improvement in SNM and ∼20× reduced energy requirements, when compared against two-cycle programming approach.

Dose Evaluation of Fractionated Schema and Distance From Tumor to Spinal Cord for Spinal SBRT with Simultaneous Integrated Boost: A Preliminary Study.

Science.gov (United States)

Yang, Hao; Cai, Bo-ning; Wang, Xiao-shen; Cong, Xiao-hu; Xu, Wei; Wang, Jin-yuan; Yang, Jun; Xu, Shou-ping; Ju, Zhong-jian; Ma, Lin

2016-02-23

BACKGROUND This study investigated and quantified the dosimetric impact of the distance from the tumor to the spinal cord and fractionation schemes for patients who received stereotactic body radiation therapy (SBRT) and hypofractionated simultaneous integrated boost (HF-SIB). MATERIAL AND METHODS Six modified planning target volumes (PTVs) for 5 patients with spinal metastases were created by artificial uniform extension in the region of PTV adjacent spinal cord with a specified minimum tumor to cord distance (0-5 mm). The prescription dose (biologic equivalent dose, BED) was 70 Gy in different fractionation schemes (1, 3, 5, and 10 fractions). For PTV V100, Dmin, D98, D95, and D1, spinal cord dose, conformity index (CI), V30 were measured and compared. RESULTS PTV-to-cord distance influenced PTV V100, Dmin, D98, and D95, and fractionation schemes influenced Dmin and D98, with a significant difference. Distances of ≥2 mm, ≥1 mm, ≥1 mm, and ≥0 mm from PTV to spinal cord meet dose requirements in 1, 3, 5, and 10 fractionations, respectively. Spinal cord dose, CI, and V30 were not impacted by PTV-to-cord distance and fractionation schemes. CONCLUSIONS Target volume coverage, Dmin, D98, and D95 were directly correlated with distance from the spinal cord for spine SBRT and HF-SIB. Based on our study, ≥2 mm, ≥1 mm, ≥1 mm, and ≥0 mm distance from PTV to spinal cord meets dose requirements in 1, 3, 5 and 10 fractionations, respectively.

Physics-preserving averaging scheme based on Grunwald-Letnikov formula for gas flow in fractured media

KAUST Repository

Amir, Sahar Z.

2018-01-02

The heterogeneous natures of rock fabrics, due to the existence of multi-scale fractures and geological formations, led to the deviations from unity in the flux-equations fractional-exponent magnitudes. In this paper, the resulting non-Newtonian non-Darcy fractional-derivatives flux equations are solved using physics-preserving averaging schemes that incorporates both, original and shifted, Grunwald-Letnikov (GL) approximation formulas preserving the physics, by reducing the shifting effects, while maintaining the stability of the system, by keeping one shifted expansion. The proposed way of using the GL expansions also generate symmetrical coefficient matrices that significantly reduces the discretization complexities appearing with all shifted cases from literature, and help considerably in 2D and 3D systems. Systems equations derivations and discretization details are discussed. Then, the physics-preserving averaging scheme is explained and illustrated. Finally, results are presented and reviewed. Edge-based original GL expansions are unstable as also illustrated in literatures. Shifted GL expansions are stable but add a lot of additional weights to both discretization sides affecting the physical accuracy. In comparison, the physics-preserving averaging scheme balances the physical accuracy and stability requirements leading to a more physically conservative scheme that is more stable than the original GL approximation but might be slightly less stable than the shifted GL approximations. It is a locally conservative Single-Continuum averaging scheme that applies a finite-volume viewpoint.

Physics-preserving averaging scheme based on Grunwald-Letnikov formula for gas flow in fractured media

KAUST Repository

Amir, Sahar Z.; Sun, Shuyu

2018-01-01

The heterogeneous natures of rock fabrics, due to the existence of multi-scale fractures and geological formations, led to the deviations from unity in the flux-equations fractional-exponent magnitudes. In this paper, the resulting non-Newtonian non-Darcy fractional-derivatives flux equations are solved using physics-preserving averaging schemes that incorporates both, original and shifted, Grunwald-Letnikov (GL) approximation formulas preserving the physics, by reducing the shifting effects, while maintaining the stability of the system, by keeping one shifted expansion. The proposed way of using the GL expansions also generate symmetrical coefficient matrices that significantly reduces the discretization complexities appearing with all shifted cases from literature, and help considerably in 2D and 3D systems. Systems equations derivations and discretization details are discussed. Then, the physics-preserving averaging scheme is explained and illustrated. Finally, results are presented and reviewed. Edge-based original GL expansions are unstable as also illustrated in literatures. Shifted GL expansions are stable but add a lot of additional weights to both discretization sides affecting the physical accuracy. In comparison, the physics-preserving averaging scheme balances the physical accuracy and stability requirements leading to a more physically conservative scheme that is more stable than the original GL approximation but might be slightly less stable than the shifted GL approximations. It is a locally conservative Single-Continuum averaging scheme that applies a finite-volume viewpoint.

Anthropology of sexual exploitation

Directory of Open Access Journals (Sweden)

Lalić Velibor

2009-01-01

Full Text Available In this paper, the authors observe sexual exploitation from an anthropological perspective. They analyze the rational, ethical, emotional and mythological dimensions of human sexuality. Consequently, after setting the phenomenon in a social and historical context, sexual exploitation is closely observed in the contemporary age. Based on thoughts of relevant thinkers, they make the conclusion that the elimination of sexual exploitation is not an utterly legal issue, but political and economical issues as well. Namely, legal norms are not sufficient to overcome sexual exploitation, but, political and economical relationships in contemporary societies, which will be based on sincere equal opportunities must be established.

Numerical Solution of Fractional Neutron Point Kinetics Model in Nuclear Reactor

Directory of Open Access Journals (Sweden)

Nowak Tomasz Karol

2014-06-01

Full Text Available This paper presents results concerning solutions of the fractional neutron point kinetics model for a nuclear reactor. Proposed model consists of a bilinear system of fractional and ordinary differential equations. Three methods to solve the model are presented and compared. The first one entails application of discrete Grünwald-Letnikov definition of the fractional derivative in the model. Second involves building an analog scheme in the FOMCON Toolbox in MATLAB environment. Third is the method proposed by Edwards. The impact of selected parameters on the model’s response was examined. The results for typical input were discussed and compared.

Projective synchronization of a complex network with different fractional order chaos nodes

International Nuclear Information System (INIS)

Wang Ming-Jun; Wang Xing-Yuan; Niu Yu-Jun

2011-01-01

Based on the stability theory of the linear fractional order system, projective synchronization of a complex network is studied in the paper, and the coupling functions of the connected nodes are identified. With this method, the projective synchronization of the network with different fractional order chaos nodes can be achieved, besides, the number of the nodes does not affect the stability of the whole network. In the numerical simulations, the chaotic fractional order Lü system, Liu system and Coullet system are chosen as examples to show the effectiveness of the scheme. (general)

Hypo-fractionated whole breast irradiation: Pro and cons; Irradiation hypofractionnee dans le cancer du sein: pour ou contre?

Energy Technology Data Exchange (ETDEWEB)

Cutuli, B. [Institut du cancer Courlancy, 38, rue de Courlancy, 51100 Reims (France); Fourquet, A. [Institut Curie, 26, rue d' Ulm, 75005 Paris (France)

2011-10-15

The continuous increase of breast cancer (BC) incidence, the logistic constraints of the protracted standard 5-week radiations regimen have led to test short hypo-fractionated whole breast radiation therapy schemes. Three prospective randomized trials and a pilot trial have been published. Large numbers of patients were included, with follow-up duration ranging from 5 to 12 years. The conclusions of these trials were similar, showing local control and toxicity equivalent to those of the standard regimen, and supporting the use of three schemes: 42.5 Gy/16 fractions/3 weeks, 40 Gy/15 fractions/3 weeks or 41.6 Gy/13 fractions/5 weeks. However, the patients in these trials had favourable prognostic factors, were treated to the breast only and the boost dose, when indicated, was delivered with a standard fractionation. Hypo-fractionated treatment can only be recommended in patients treated to the breast only, without nodal involvement, with grade < 3 tumours and who are not candidate to chemotherapy. If a boost is to be given, a standard fractionation should be used. Particular care should be taken to avoid heterogeneities leading to high fractional doses to organs at risk (lung and heart). (authors)

Fourier spectral methods for fractional-in-space reaction-diffusion equations

KAUST Repository

Bueno-Orovio, Alfonso

2014-04-01

© 2014, Springer Science+Business Media Dordrecht. Fractional differential equations are becoming increasingly used as a powerful modelling approach for understanding the many aspects of nonlocality and spatial heterogeneity. However, the numerical approximation of these models is demanding and imposes a number of computational constraints. In this paper, we introduce Fourier spectral methods as an attractive and easy-to-code alternative for the integration of fractional-in-space reaction-diffusion equations described by the fractional Laplacian in bounded rectangular domains of ℝ. The main advantages of the proposed schemes is that they yield a fully diagonal representation of the fractional operator, with increased accuracy and efficiency when compared to low-order counterparts, and a completely straightforward extension to two and three spatial dimensions. Our approach is illustrated by solving several problems of practical interest, including the fractional Allen–Cahn, FitzHugh–Nagumo and Gray–Scott models, together with an analysis of the properties of these systems in terms of the fractional power of the underlying Laplacian operator.

‘Tied Visas’ and Inadequate Labour Protections: A formula for abuse and exploitation of migrant domestic workers in the United Kingdom

Directory of Open Access Journals (Sweden)

Daphne Demetriou

2015-09-01

Full Text Available This article examines the link between restrictive immigration schemes, specifically ‘tied visas’ and the selective application of labour laws, with exploitation of workers. It focuses on the situation of migrant domestic workers, who accompany their employers to the United Kingdom (UK and are exposed to both an excessively restrictive visa regime, introduced in April 2012, and limited labour protections. The immigration status of these workers is currently tied to a named employer, a restriction that traps workers into exploitative conditions, often amounting to forced labour, servitude or slavery. Additionally, current UK labour laws are either not enforced or not applicable to domestic workers. The article concludes that unless the current immigration regime is abolished and comprehensive labour law protections are extended to migrant domestic workers, exploitation will continue.

The exploitation argument against commercial surrogacy.

Science.gov (United States)

Wilkinson, Stephen

2003-04-01

This paper discusses the exploitation argument against commercial surrogacy: the claim that commercial surrogacy is morally objectionable because it is exploitative. The following questions are addressed. First, what exactly does the exploitation argument amount to? Second, is commercial surrogacy in fact exploitative? Third, if it were exploitative, would this provide a sufficient reason to prohibit (or otherwise legislatively discourage) it? The focus throughout is on the exploitation of paid surrogates, although it is noted that other parties (e.g. 'commissioning parents') may also be the victims of exploitation. It is argued that there are good reasons for believing that commercial surrogacy is often exploitative. However, even if we accept this, the exploitation argument for prohibiting (or otherwise legislatively discouraging) commercial surrogacy remains quite weak. One reason for this is that prohibition may well 'backfire' and lead to potential surrogates having to do other things that are more exploitative and/or more harmful than paid surrogacy. It is concluded therefore that those who oppose exploitation should (rather than attempting to stop particular practices like commercial surrogacy) concentrate on: (a) improving the conditions under which paid surrogates 'work'; and (b) changing the background conditions (in particular, the unequal distribution of power and wealth) which generate exploitative relationships.

Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

Energy Technology Data Exchange (ETDEWEB)

Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M. [Radiotherapy Centre West, The Hague (Netherlands); Molenaar, R. [Diaconessenhuis, Leiden (Netherlands). Dept. of Neurology; Lycklama a Nijeholt, G. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Radiology; Vecht, C. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Neurology; Struikmans, H. [Radiotherapy Centre West, The Hague (Netherlands); Leiden Univ. Medical Centre (Netherlands). Dept. of Radiotherapy; Kal, H.B.

2012-08-15

Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm{sup 3} or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

International Nuclear Information System (INIS)

Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M.; Molenaar, R.; Lycklama a Nijeholt, G.; Vecht, C.; Struikmans, H.; Leiden Univ. Medical Centre; Kal, H.B.

2012-01-01

Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm 3 or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

Three-batch reloading scheme for IRIS reactor extended cycles

International Nuclear Information System (INIS)

Jecmenica, R.; Pevec, D.; Grgic, D.

2004-01-01

To fully exploit the IRIS reactor optimized maintenance, and at the same time improve fuel utilization, a core design enabling a 4-year operating cycle together with a three-batch reloading scheme is desirable. However, this requires not only the increased allowed burnup but also use of fuel with uranium oxide enriched beyond 5%. This paper considers three-batch reloading scheme for a 4-year operating cycle with the assumptions of increased discharge burnup and fuel enrichment beyond 5%. Calculational model of IRIS reactor core has been developed based on FER FA2D code for group constants generation and NRC's PARCS nodal code for global core analysis. Studies have been performed resulting in a preliminary design of a three-batch core configuration for the first cycle. It must be emphasized that this study is outside the current IRIS licensing efforts, which rely on the present fuel technology (enrichment below 5%), but it is of long-term interest for potential future IRIS design upgrades. (author)

Exploitability Assessment with TEASER

Science.gov (United States)

2017-05-01

for architectural neutral taint analysis on top of LLVM and QEMU. POC Proof of Concept : Demonstration of an exploit on a program . vii RCE Remote Code...bug with a Proof of Concept (POC), or input to a program demonstrating the ability to use a bug to exploit the application, to demonstrate the...often leads to either computationally difficult constraint solving problems or taint explosion. Given the computational difficulty of exploit

Anonymous authentication and location privacy preserving schemes for LTE-A networks

Directory of Open Access Journals (Sweden)

Zaher Jabr Haddad

2017-11-01

Full Text Available Long Term Evaluation Advanced (LTE-A is the third generation partnership project for cellular network that allows subscribers to roam into networks (i.e., the Internet and wireless connections using spacial purpose base-stations, such as wireless access points and home node B. In such LTE-A based networks, neither base-stations, nor the Internet and wireless connections are trusted because base-stations are operated by un-trusted subscribers. Attackers may exploit these vulnerabilities to violate the privacy of the LTE-A subscribers. On the other hand, the tradeoff between privacy and authentication is another challenge in such networks. Therefore, in this paper, we propose two anonymous authentication schemes based on one-time pseudonymes and Schnorr Zero Knowledge Protocols. Instead of the international mobile subscriber identity, these schemes enable the user equipment, base-stations and mobility management entity to mutually authenticate each others and update the location of the user equipment without evolving the home subscriber server. The security analysis demonstrate that the proposed schemes thwart security and privacy attacks, such as malicious, international mobile subscriber identity catching, and tracking attacks. Additionally, our proposed schemes preserve the location privacy of user equipment since no entity except the mobility management entity and Gate-Way Mobile Location Center can link between the pseudonymes and the international mobile subscriber identity. Also attackers have no knowledge about international mobile subscriber identity. Hence, the proposed schemes achieve backward/forward secrecy. Furthermore, the performance evaluation shows that the proposed handover schemes impose a small overhead on the mobile nodes and it has smaller computation and communication overheads than those in other schemes.

Fractional neutron point kinetics equations for nuclear reactor dynamics

International Nuclear Information System (INIS)

Espinosa-Paredes, Gilberto; Polo-Labarrios, Marco-A.; Espinosa-Martinez, Erick-G.; Valle-Gallegos, Edmundo del

2011-01-01

The fractional point-neutron kinetics model for the dynamic behavior in a nuclear reactor is derived and analyzed in this paper. The fractional model retains the main dynamic characteristics of the neutron motion in which the relaxation time associated with a rapid variation in the neutron flux contains a fractional order, acting as exponent of the relaxation time, to obtain the best representation of a nuclear reactor dynamics. The physical interpretation of the fractional order is related with non-Fickian effects from the neutron diffusion equation point of view. The numerical approximation to the solution of the fractional neutron point kinetics model, which can be represented as a multi-term high-order linear fractional differential equation, is calculated by reducing the problem to a system of ordinary and fractional differential equations. The numerical stability of the fractional scheme is investigated in this work. Results for neutron dynamic behavior for both positive and negative reactivity and for different values of fractional order are shown and compared with the classic neutron point kinetic equations. Additionally, a related review with the neutron point kinetics equations is presented, which encompasses papers written in English about this research topic (as well as some books and technical reports) published since 1940 up to 2010.

Two questions about surrogacy and exploitation.

Science.gov (United States)

Wertheimer, Alan

1992-01-01

In this article I will consider two related questions about surrogacy and exploitation: (1) Is surrogacy exploitative? (2) If surrogacy is exploitative, what is the moral force of this exploitation? Briefly stated, I shall argue that whether surrogacy is exploitative depends on whether exploitation must be harmful to the exploited party or whether (as I think) there can be mutually advantageous exploitation. It also depends on some facts about surrogacy about which we have little reliable evidence and on our philosophical view on what counts as a harm to the surrogate. Our answer to the second question will turn in part on the account of exploitation we invoke in answering the first question and in part on the way in which we resolve some other questions about the justification of state interference. I shall suggest, however, that if surrogacy is a form of voluntary and mutually advantageous exploitation, then there is a strong presumption that surrogacy contracts should be permitted and even enforceable, although that presumption may be overridden on other grounds.

CAC DPLB MCN: A Distributed Load Balancing Scheme in Multimedia Mobile Cellular Networks

Directory of Open Access Journals (Sweden)

Sharma Abhijit

2016-11-01

Full Text Available The problem of non-uniform traffic demand in different cells of a cellular network may lead to a gross imbalance in the system performance. Thus, the users in hot cells may suffer from low throughput. In this paper, an effective and simple load balancing scheme CAC_DPLB_MCN is proposed that can effectively reduce the overall call blocking. This model considers dealing with multi-media traffic as well as time-varying geographical traffic distribution. The proposed scheme uses the concept of cell-tiering thereby creating fractional frequency reuse environment. A message exchange based distributed scheme instead of centralized one is used which help the proposed scheme be implemented in a multiple hot cell environment also. Furthermore, concept of dynamic pricing is used to serve the best interest of the users as well as for the service providers. The performance of the proposed scheme is compared with two other existing schemes in terms of call blocking probability and bandwidth utilization. Simulation results show that the proposed scheme can reduce the call blocking significantly in highly congested cell with highest bandwidth utilization. Use of dynamic pricing also makes the scheme useful to increase revenue of the service providers in contrast with compared schemes.

Exploit Kit traffic analysis

OpenAIRE

Καπίρης, Σταμάτης; Kapiris, Stamatis

2017-01-01

Exploit kits have become one of the most widespread and destructive threat that Internet users face on a daily basis. Since the first actor, which has been categorized as exploit kit, namely MPack, appeared in 2006, we have seen a new era on exploit kit variants compromising popular websites, infecting hosts and delivering destructive malware, following an exponentially evolvement to date. With the growing threat landscape, large enterprises to domestic networks, have starte...

A factorial assessment of the sensitivity of the BATS land-surface parameterization scheme. [BATS (Biosphere-Atmosphere Transfer Scheme)

Energy Technology Data Exchange (ETDEWEB)

Henderson-Sellers, A. (Macquarie Univ., North Ryde, New South Wales (Australia))

1993-02-01

Land-surface schemes developed for incorporation into global climate models include parameterizations that are not yet fully validated and depend upon the specification of a large (20-50) number of ecological and soil parameters, the values of which are not yet well known. There are two methods of investigating the sensitivity of a land-surface scheme to prescribed values: simple one-at-a-time changes or factorial experiments. Factorial experiments offer information about interactions between parameters and are thus a more powerful tool. Here the results of a suite of factorial experiments are reported. These are designed (i) to illustrate the usefulness of this methodology and (ii) to identify factors important to the performance of complex land-surface schemes. The Biosphere-Atmosphere Transfer Scheme (BATS) is used and its sensitivity is considered (a) to prescribed ecological and soil parameters and (b) to atmospheric forcing used in the off-line tests undertaken. Results indicate that the most important atmospheric forcings are mean monthly temperature and the interaction between mean monthly temperature and total monthly precipitation, although fractional cloudiness and other parameters are also important. The most important ecological parameters are vegetation roughness length, soil porosity, and a factor describing the sensitivity of the stomatal resistance of vegetation to the amount of photosynthetically active solar radiation and, to a lesser extent, soil and vegetation albedos. Two-factor interactions including vegetation roughness length are more important than many of the 23 specified single factors. The results of factorial sensitivity experiments such as these could form the basis for intercomparison of land-surface parameterization schemes and for field experiments and satellite-based observation programs aimed at improving evaluation of important parameters.

Pressure correction schemes for compressible flows

International Nuclear Information System (INIS)

Kheriji, W.

2011-01-01

This thesis is concerned with the development of semi-implicit fractional step schemes, for the compressible Navier-Stokes equations; these schemes are part of the class of the pressure correction methods. The chosen spatial discretization is staggered: non conforming mixed finite elements (Crouzeix-Raviart or Rannacher-Turek) or the classic MA C scheme. An upwind finite volume discretization of the mass balance guarantees the positivity of the density. The positivity of the internal energy is obtained by discretizing the internal energy balance by an upwind finite volume scheme and b y coupling the discrete internal energy balance with the pressure correction step. A special finite volume discretization on dual cells is performed for the convection term in the momentum balance equation, and a renormalisation step for the pressure is added to the algorithm; this ensures the control in time of the integral of the total energy over the domain. All these a priori estimates imply the existence of a discrete solution by a topological degree argument. The application of this scheme to Euler equations raises an additional difficulty. Indeed, obtaining correct shocks requires the scheme to be consistent with the total energy balance, property which we obtain as follows. First of all, a local discrete kinetic energy balance is established; it contains source terms winch we somehow compensate in the internal energy balance. The kinetic and internal energy equations are associated with the dual and primal meshes respectively, and thus cannot be added to obtain a total energy balance; its continuous counterpart is however recovered at the limit: if we suppose that a sequence of discrete solutions converges when the space and time steps tend to 0, we indeed show, in 1D at least, that the limit satisfies a weak form of the equation. These theoretical results are comforted by numerical tests. Similar results are obtained for the baro-tropic Navier-Stokes equations. (author)

Simulating transient dynamics of the time-dependent time fractional Fokker–Planck systems

Energy Technology Data Exchange (ETDEWEB)

Kang, Yan-Mei, E-mail: ymkang@mail.xjtu.edu.cn

2016-09-16

For a physically realistic type of time-dependent time fractional Fokker–Planck (FP) equation, derived as the continuous limit of the continuous time random walk with time-modulated Boltzmann jumping weight, a semi-analytic iteration scheme based on the truncated (generalized) Fourier series is presented to simulate the resultant transient dynamics when the external time modulation is a piece-wise constant signal. At first, the iteration scheme is demonstrated with a simple time-dependent time fractional FP equation on finite interval with two absorbing boundaries, and then it is generalized to the more general time-dependent Smoluchowski-type time fractional Fokker–Planck equation. The numerical examples verify the efficiency and accuracy of the iteration method, and some novel dynamical phenomena including polarized motion orientations and periodic response death are discussed. - Highlights: • An iteration method is proposed for the transient dynamics of time-dependent time fractional Fokker–Planck equations. • The method is based on Fourier Series solution and the multi-step transition probability formula. • With the time-modulated subdiffusion on finite interval as example, the polarized motion orientation is disclosed. • With the time-modulated subdiffusion within a confined potential as example, the death of dynamic response is observed.

Simulating transient dynamics of the time-dependent time fractional Fokker–Planck systems

International Nuclear Information System (INIS)

Kang, Yan-Mei

2016-01-01

For a physically realistic type of time-dependent time fractional Fokker–Planck (FP) equation, derived as the continuous limit of the continuous time random walk with time-modulated Boltzmann jumping weight, a semi-analytic iteration scheme based on the truncated (generalized) Fourier series is presented to simulate the resultant transient dynamics when the external time modulation is a piece-wise constant signal. At first, the iteration scheme is demonstrated with a simple time-dependent time fractional FP equation on finite interval with two absorbing boundaries, and then it is generalized to the more general time-dependent Smoluchowski-type time fractional Fokker–Planck equation. The numerical examples verify the efficiency and accuracy of the iteration method, and some novel dynamical phenomena including polarized motion orientations and periodic response death are discussed. - Highlights: • An iteration method is proposed for the transient dynamics of time-dependent time fractional Fokker–Planck equations. • The method is based on Fourier Series solution and the multi-step transition probability formula. • With the time-modulated subdiffusion on finite interval as example, the polarized motion orientation is disclosed. • With the time-modulated subdiffusion within a confined potential as example, the death of dynamic response is observed.

Exploiting the bead-injection approach in the integrated sequential injection Lab-on-Valve format using hydrophobic packing materials for on-line matrix removal and preconcentration of trace levels of cadmium in environmental and biological samples via formation of non-charged chelates prior

DEFF Research Database (Denmark)

Miró, Manuel; Jonczyk, Sylwia; Wang, Jianhua

2003-01-01

The concept of renewable microcolumns within the conduits of an automated single injection lab-on-valve system was exploited in a sorption/elution fashion using sorbents of hydrophobic nature. The scheme's practical applicability was demonstrated for the electrothermal atomic absorption spectrome......The concept of renewable microcolumns within the conduits of an automated single injection lab-on-valve system was exploited in a sorption/elution fashion using sorbents of hydrophobic nature. The scheme's practical applicability was demonstrated for the electrothermal atomic absorption...

An entropy-variables-based formulation of residual distribution schemes for non-equilibrium flows

Science.gov (United States)

Garicano-Mena, Jesús; Lani, Andrea; Degrez, Gérard

2018-06-01

In this paper we present an extension of Residual Distribution techniques for the simulation of compressible flows in non-equilibrium conditions. The latter are modeled by means of a state-of-the-art multi-species and two-temperature model. An entropy-based variable transformation that symmetrizes the projected advective Jacobian for such a thermophysical model is introduced. Moreover, the transformed advection Jacobian matrix presents a block diagonal structure, with mass-species and electronic-vibrational energy being completely decoupled from the momentum and total energy sub-system. The advantageous structure of the transformed advective Jacobian can be exploited by contour-integration-based Residual Distribution techniques: established schemes that operate on dense matrices can be substituted by the same scheme operating on the momentum-energy subsystem matrix and repeated application of scalar scheme to the mass-species and electronic-vibrational energy terms. Finally, the performance gain of the symmetrizing-variables formulation is quantified on a selection of representative testcases, ranging from subsonic to hypersonic, in inviscid or viscous conditions.

An adaptive scaling and biasing scheme for OFDM-based visible light communication systems.

Science.gov (United States)

Wang, Zhaocheng; Wang, Qi; Chen, Sheng; Hanzo, Lajos

2014-05-19

Orthogonal frequency-division multiplexing (OFDM) has been widely used in visible light communication systems to achieve high-rate data transmission. Due to the nonlinear transfer characteristics of light emitting diodes (LEDs) and owing the high peak-to-average-power ratio of OFDM signals, the transmitted signal has to be scaled and biased before modulating the LEDs. In this contribution, an adaptive scaling and biasing scheme is proposed for OFDM-based visible light communication systems, which fully exploits the dynamic range of the LEDs and improves the achievable system performance. Specifically, the proposed scheme calculates near-optimal scaling and biasing factors for each specific OFDM symbol according to the distribution of the signals, which strikes an attractive trade-off between the effective signal power and the clipping-distortion power. Our simulation results demonstrate that the proposed scheme significantly improves the performance without changing the LED's emitted power, while maintaining the same receiver structure.

Outer synchronization between two different fractional-order general complex dynamical networks

International Nuclear Information System (INIS)

Xiang-Jun, Wu; Hong-Tao, Lu

2010-01-01

Outer synchronization between two different fractional-order general complex dynamical networks is investigated in this paper. Based on the stability theory of the fractional-order system, the sufficient criteria for outer synchronization are derived analytically by applying the nonlinear control and the bidirectional coupling methods. The proposed synchronization method is applicable to almost all kinds of coupled fractional-order general complex dynamical networks. Neither a symmetric nor irreducible coupling configuration matrix is required. In addition, no constraint is imposed on the inner-coupling matrix. Numerical examples are also provided to demonstrate the validity of the presented synchronization scheme. Numeric evidence shows that both the feedback strength k and the fractional order α can be chosen appropriately to adjust the synchronization effect effectively. (general)

Special Semaphore Scheme for UHF Spacecraft Communications

Science.gov (United States)

Butman, Stanley; Satorius, Edgar; Ilott, Peter

2006-01-01

A semaphore scheme has been devised to satisfy a requirement to enable ultrahigh- frequency (UHF) radio communication between a spacecraft descending from orbit to a landing on Mars and a spacecraft, in orbit about Mars, that relays communications between Earth and the lander spacecraft. There are also two subsidiary requirements: (1) to use UHF transceivers, built and qualified for operation aboard the spacecraft that operate with residual-carrier binary phase-shift-keying (BPSK) modulation at a selectable data rate of 8, 32, 128, or 256 kb/s; and (2) to enable low-rate signaling even when received signals become so weak as to prevent communication at the minimum BPSK rate of 8 kHz. The scheme involves exploitation of Manchester encoding, which is used in conjunction with residual-carrier modulation to aid the carrier-tracking loop. By choosing various sequences of 1s, 0s, or 1s alternating with 0s to be fed to the residual-carrier modulator, one would cause the modulator to generate sidebands at a fundamental frequency of 4 or 8 kHz and harmonics thereof. These sidebands would constitute the desired semaphores. In reception, the semaphores would be detected by a software demodulator.

A new modification in the exponential rational function method for nonlinear fractional differential equations

Science.gov (United States)

Ahmed, Naveed; Bibi, Sadaf; Khan, Umar; Mohyud-Din, Syed Tauseef

2018-02-01

We have modified the traditional exponential rational function method (ERFM) and have used it to find the exact solutions of two different fractional partial differential equations, one is the time fractional Boussinesq equation and the other is the (2+1)-dimensional time fractional Zoomeron equation. In both the cases it is observed that the modified scheme provides more types of solutions than the traditional one. Moreover, a comparison of the recent solutions is made with some already existing solutions. We can confidently conclude that the modified scheme works better and provides more types of solutions with almost similar computational cost. Our generalized solutions include periodic, soliton-like, singular soliton and kink solutions. A graphical simulation of all types of solutions is provided and the correctness of the solution is verified by direct substitution. The extended version of the solutions is expected to provide more flexibility to scientists working in the relevant field to test their simulation data.

A positive and entropy-satisfying finite volume scheme for the Baer-Nunziato model

Science.gov (United States)

Coquel, Frédéric; Hérard, Jean-Marc; Saleh, Khaled

2017-02-01

We present a relaxation scheme for approximating the entropy dissipating weak solutions of the Baer-Nunziato two-phase flow model. This relaxation scheme is straightforwardly obtained as an extension of the relaxation scheme designed in [16] for the isentropic Baer-Nunziato model and consequently inherits its main properties. To our knowledge, this is the only existing scheme for which the approximated phase fractions, phase densities and phase internal energies are proven to remain positive without any restrictive condition other than a classical fully computable CFL condition. For ideal gas and stiffened gas equations of state, real values of the phasic speeds of sound are also proven to be maintained by the numerical scheme. It is also the only scheme for which a discrete entropy inequality is proven, under a CFL condition derived from the natural sub-characteristic condition associated with the relaxation approximation. This last property, which ensures the non-linear stability of the numerical method, is satisfied for any admissible equation of state. We provide a numerical study for the convergence of the approximate solutions towards some exact Riemann solutions. The numerical simulations show that the relaxation scheme compares well with two of the most popular existing schemes available for the Baer-Nunziato model, namely Schwendeman-Wahle-Kapila's Godunov-type scheme [39] and Tokareva-Toro's HLLC scheme [44]. The relaxation scheme also shows a higher precision and a lower computational cost (for comparable accuracy) than a standard numerical scheme used in the nuclear industry, namely Rusanov's scheme. Finally, we assess the good behavior of the scheme when approximating vanishing phase solutions.

Topological Fractional Pumping with Alkaline-Earth-Like Atoms in Synthetic Lattices

Science.gov (United States)

Taddia, Luca; Cornfeld, Eyal; Rossini, Davide; Mazza, Leonardo; Sela, Eran; Fazio, Rosario

2017-06-01

Alkaline-earth(-like) atoms, trapped in optical lattices and in the presence of an external gauge field, can form insulating states at given fractional fillings. We will show that, by exploiting these properties, it is possible to realize a topological fractional pump. Our analysis is based on a many-body adiabatic expansion, on simulations with time-dependent matrix product states, and, for a specific form of atom-atom interaction, on an exactly solvable model of fractional pump. The numerical simulations allow us to consider a realistic setup amenable of an experimental realization. As a further consequence, the measure of the center-of-mass shift of the atomic cloud would constitute the first measurement of a many-body Chern number in a cold-atom experiment.

Analytical and Numerical solutions of a nonlinear alcoholism model via variable-order fractional differential equations

Science.gov (United States)

Gómez-Aguilar, J. F.

2018-03-01

In this paper, we analyze an alcoholism model which involves the impact of Twitter via Liouville-Caputo and Atangana-Baleanu-Caputo fractional derivatives with constant- and variable-order. Two fractional mathematical models are considered, with and without delay. Special solutions using an iterative scheme via Laplace and Sumudu transform were obtained. We studied the uniqueness and existence of the solutions employing the fixed point postulate. The generalized model with variable-order was solved numerically via the Adams method and the Adams-Bashforth-Moulton scheme. Stability and convergence of the numerical solutions were presented in details. Numerical examples of the approximate solutions are provided to show that the numerical methods are computationally efficient. Therefore, by including both the fractional derivatives and finite time delays in the alcoholism model studied, we believe that we have established a more complete and more realistic indicator of alcoholism model and affect the spread of the drinking.

A New Grünwald-Letnikov Derivative Derived from a Second-Order Scheme

Directory of Open Access Journals (Sweden)

B. A. Jacobs

2015-01-01

Full Text Available A novel derivation of a second-order accurate Grünwald-Letnikov-type approximation to the fractional derivative of a function is presented. This scheme is shown to be second-order accurate under certain modifications to account for poor accuracy in approximating the asymptotic behavior near the lower limit of differentiation. Some example functions are chosen and numerical results are presented to illustrate the efficacy of this new method over some other popular choices for discretizing fractional derivatives.

Synchronization and an application of a novel fractional order King Cobra chaotic system

Energy Technology Data Exchange (ETDEWEB)

Muthukumar, P., E-mail: muthukumardgl@gmail.com; Balasubramaniam, P., E-mail: balugru@gmail.com [Department of Mathematics, Gandhigram Rural Institute‐Deemed University, Gandhigram 624 302, Tamilnadu (India); Ratnavelu, K., E-mail: kuru052001@gmail.com [Faculty of Science, Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2014-09-01

In this paper, we design a new three dimensional King Cobra face shaped fractional order chaotic system. The multi-scale synchronization scheme of two fractional order chaotic systems is described. The necessary conditions for the multi-scale synchronization of two identical fractional order King Cobra chaotic systems are derived through feedback control. A new cryptosystem is proposed for an image encryption and decryption by using synchronized fractional order King Cobra chaotic systems with the supports of multiple cryptographic assumptions. The security of the proposed cryptosystem is analyzed by the well known algebraic attacks. Numerical simulations are given to show the effectiveness of the proposed theoretical results.

Nuclear Reactor Component Code CUPID-I: Numerical Scheme and Preliminary Assessment Results

International Nuclear Information System (INIS)

Cho, Hyoung Kyu; Jeong, Jae Jun; Park, Ik Kyu; Kim, Jong Tae; Yoon, Han Young

2007-12-01

A component scale thermal hydraulic analysis code, CUPID (Component Unstructured Program for Interfacial Dynamics), is being developed for the analysis of components of a nuclear reactor, such as reactor vessel, steam generator, containment, etc. It adopted three-dimensional, transient, two phase and three-field model. In order to develop the numerical schemes for the three-field model, various numerical schemes have been examined including the SMAC, semi-implicit ICE, SIMPLE, Row Scheme and so on. Among them, the ICE scheme for the three-field model was presented in the present report. The CUPID code is utilizing unstructured mesh for the simulation of complicated geometries of the nuclear reactor components. The conventional ICE scheme that was applied to RELAP5 and COBRA-TF, therefore, were modified for the application to the unstructured mesh. Preliminary calculations for the unstructured semi-implicit ICE scheme have been conducted for a verification of the numerical method from a qualitative point of view. The preliminary calculation results showed that the present numerical scheme is robust and efficient for the prediction of phase changes and flow transitions due to a boiling and a flashing. These calculation results also showed the strong coupling between the pressure and void fraction changes. Thus, it is believed that the semi-implicit ICE scheme can be utilized for transient two-phase flows in a component of a nuclear reactor

Nuclear Reactor Component Code CUPID-I: Numerical Scheme and Preliminary Assessment Results

Energy Technology Data Exchange (ETDEWEB)

Cho, Hyoung Kyu; Jeong, Jae Jun; Park, Ik Kyu; Kim, Jong Tae; Yoon, Han Young

2007-12-15

A component scale thermal hydraulic analysis code, CUPID (Component Unstructured Program for Interfacial Dynamics), is being developed for the analysis of components of a nuclear reactor, such as reactor vessel, steam generator, containment, etc. It adopted three-dimensional, transient, two phase and three-field model. In order to develop the numerical schemes for the three-field model, various numerical schemes have been examined including the SMAC, semi-implicit ICE, SIMPLE, Row Scheme and so on. Among them, the ICE scheme for the three-field model was presented in the present report. The CUPID code is utilizing unstructured mesh for the simulation of complicated geometries of the nuclear reactor components. The conventional ICE scheme that was applied to RELAP5 and COBRA-TF, therefore, were modified for the application to the unstructured mesh. Preliminary calculations for the unstructured semi-implicit ICE scheme have been conducted for a verification of the numerical method from a qualitative point of view. The preliminary calculation results showed that the present numerical scheme is robust and efficient for the prediction of phase changes and flow transitions due to a boiling and a flashing. These calculation results also showed the strong coupling between the pressure and void fraction changes. Thus, it is believed that the semi-implicit ICE scheme can be utilized for transient two-phase flows in a component of a nuclear reactor.

The Galerkin Finite Element Method for A Multi-term Time-Fractional Diffusion equation

OpenAIRE

Jin, Bangti; Lazarov, Raytcho; Liu, Yikan; Zhou, Zhi

2014-01-01

We consider the initial/boundary value problem for a diffusion equation involving multiple time-fractional derivatives on a bounded convex polyhedral domain. We analyze a space semidiscrete scheme based on the standard Galerkin finite element method using continuous piecewise linear functions. Nearly optimal error estimates for both cases of initial data and inhomogeneous term are derived, which cover both smooth and nonsmooth data. Further we develop a fully discrete scheme based on a finite...

A study on the potential of cell kinetically directed fractionation schemes in radiotherapy

International Nuclear Information System (INIS)

Oostrum, I.E.A. van.

1990-01-01

In this thesis, the phenomenon of radiation-induced synchronization of cells into the radiosensitive G 2 phase of the cell cycle and the exploitation of this phenomenon to enhance the efficacy of frationated radiotherapy was investigated. A nude mouse model was used to investigate the cell kinetics of 6 human xenotransplanted tumours before and after irradiation. In the second part of the investigation it was tested whether split dose irradiation intervals, based on cell kinetic data of the tumours (i.e. timing of maximal accumulation of cells in G 2 ) would result in an enhanced response compared with those at non optimal intervals (author), 297 refs.; 35 figs.; 25 tabs

Numerical Schemes for Rough Parabolic Equations

Energy Technology Data Exchange (ETDEWEB)

Deya, Aurelien, E-mail: deya@iecn.u-nancy.fr [Universite de Nancy 1, Institut Elie Cartan Nancy (France)

2012-04-15

This paper is devoted to the study of numerical approximation schemes for a class of parabolic equations on (0,1) perturbed by a non-linear rough signal. It is the continuation of Deya (Electron. J. Probab. 16:1489-1518, 2011) and Deya et al. (Probab. Theory Relat. Fields, to appear), where the existence and uniqueness of a solution has been established. The approach combines rough paths methods with standard considerations on discretizing stochastic PDEs. The results apply to a geometric 2-rough path, which covers the case of the multidimensional fractional Brownian motion with Hurst index H>1/3.

A new measure of interpersonal exploitativeness

Directory of Open Access Journals (Sweden)

Amy B. Brunell

2013-05-01

Full Text Available Measures of exploitativeness evidence problems with validity and reliability. The present set of studies assessed a new measure (the Interpersonal Exploitativeness Scale that defines exploitativeness in terms of reciprocity. In Studies 1 and 2, 33 items were administered to participants. Exploratory and Confirmatory Factor Analysis demonstrated that a single factor consisting of six items adequately assess interpersonal exploitativeness. Study 3 results revealed that the Interpersonal Exploitativeness Scale was positively associated with normal narcissism, pathological narcissism, psychological entitlement, and negative reciprocity and negatively correlated with positive reciprocity. In Study 4, participants competed in a commons dilemma. Those who scored higher on the Interpersonal Exploitativeness Scale were more likely to harvest a greater share of resources over time, even while controlling for other relevant variables, such as entitlement. Together, these studies show the Interpersonal Exploitativeness Scale to be a valid and reliable measure of interpersonal exploitativeness. The authors discuss the implications of these studies.

Maximum-principle-satisfying space-time conservation element and solution element scheme applied to compressible multifluids

KAUST Repository

Shen, Hua; Wen, Chih-Yung; Parsani, Matteo; Shu, Chi-Wang

2016-01-01

A maximum-principle-satisfying space-time conservation element and solution element (CE/SE) scheme is constructed to solve a reduced five-equation model coupled with the stiffened equation of state for compressible multifluids. We first derive a sufficient condition for CE/SE schemes to satisfy maximum-principle when solving a general conservation law. And then we introduce a slope limiter to ensure the sufficient condition which is applicative for both central and upwind CE/SE schemes. Finally, we implement the upwind maximum-principle-satisfying CE/SE scheme to solve the volume-fraction-based five-equation model for compressible multifluids. Several numerical examples are carried out to carefully examine the accuracy, efficiency, conservativeness and maximum-principle-satisfying property of the proposed approach.

Maximum-principle-satisfying space-time conservation element and solution element scheme applied to compressible multifluids

KAUST Repository

Shen, Hua

2016-10-19

A maximum-principle-satisfying space-time conservation element and solution element (CE/SE) scheme is constructed to solve a reduced five-equation model coupled with the stiffened equation of state for compressible multifluids. We first derive a sufficient condition for CE/SE schemes to satisfy maximum-principle when solving a general conservation law. And then we introduce a slope limiter to ensure the sufficient condition which is applicative for both central and upwind CE/SE schemes. Finally, we implement the upwind maximum-principle-satisfying CE/SE scheme to solve the volume-fraction-based five-equation model for compressible multifluids. Several numerical examples are carried out to carefully examine the accuracy, efficiency, conservativeness and maximum-principle-satisfying property of the proposed approach.

Gait-Cycle-Driven Transmission Power Control Scheme for a Wireless Body Area Network.

Science.gov (United States)

Zang, Weilin; Li, Ye

2018-05-01

In a wireless body area network (WBAN), walking movements can result in rapid channel fluctuations, which severely degrade the performance of transmission power control (TPC) schemes. On the other hand, these channel fluctuations are often periodic and are time-synchronized with the user's gait cycle, since they are all driven from the walking movements. In this paper, we propose a novel gait-cycle-driven transmission power control (G-TPC) for a WBAN. The proposed G-TPC scheme reinforces the existing TPC scheme by exploiting the periodic channel fluctuation in the walking scenario. In the proposed scheme, the user's gait cycle information acquired by an accelerometer is used as beacons for arranging the transmissions at the time points with the ideal channel state. The specific transmission power is then determined by using received signal strength indication (RSSI). An experiment was conducted to evaluate the energy efficiency and reliability of the proposed G-TPC based on a CC2420 platform. The results reveal that compared to the original RSSI/link-quality-indication-based TPC, G-TPC reduces energy consumption by 25% on the sensor node and reduce the packet loss rate by 65%.

A Novel Secure Transmission Scheme in MIMO Two-Way Relay Channels with Physical Layer Approach

Directory of Open Access Journals (Sweden)

Qiao Liu

2017-01-01

Full Text Available Security issue has been considered as one of the most pivotal aspects for the fifth-generation mobile network (5G due to the increasing demands of security service as well as the growing occurrence of security threat. In this paper, instead of focusing on the security architecture in the upper layer, we investigate the secure transmission for a basic channel model in a heterogeneous network, that is, two-way relay channels. By exploiting the properties of the transmission medium in the physical layer, we propose a novel secure scheme for the aforementioned channel mode. With precoding design, the proposed scheme is able to achieve a high transmission efficiency as well as security. Two different approaches have been introduced: information theoretical approach and physical layer encryption approach. We show that our scheme is secure under three different adversarial models: (1 untrusted relay attack model, (2 trusted relay with eavesdropper attack model, and (3 untrusted relay with eavesdroppers attack model. We also derive the secrecy capacity of the two different approaches under the three attacks. Finally, we conduct three simulations of our proposed scheme. The simulation results agree with the theoretical analysis illustrating that our proposed scheme could achieve a better performance than the existing schemes.

Exploiting flow Injection and sequential injection schemes for trace metal determinations by electrothermal atomic absorption spectrometry

DEFF Research Database (Denmark)

Hansen, Elo Harald

Determination of low or trace-level amounts of metals by electrothermal atomic absorption spectrometry (ETAAS) often requires the use of suitable preconcentration and/or separation procedures in order to attain the necessary sensitivity and selectivity. Such schemes are advantageously executed...... by superior performance and versatility. In fact, two approaches are conceivable: The analyte-loaded ion-exchange beads might either be transported directly into the graphite tube where they are pyrolized and the measurand is atomized and quantified; or the loaded beads can be eluted and the eluate forwarded...

Why and how to compensate living organ donors: ethical implications of the new Australian scheme.

Science.gov (United States)

Giubilini, Alberto

2015-05-01

The Australian Federal Government has announced a two-year trial scheme to compensate living organ donors. The compensation will be the equivalent of six weeks paid leave at the rate of the national minimum wage. In this article I analyse the ethics of compensating living organ donors taking the Australian scheme as a reference point. Considering the long waiting lists for organ transplantations and the related costs on the healthcare system of treating patients waiting for an organ, the 1.3 million AUD the Australian Government has committed might represent a very worthwhile investment. I argue that a scheme like the Australian one is sufficiently well designed to avoid all the ethical problems traditionally associated with attaching a monetary value to the human body or to parts of it, namely commodification, inducement, exploitation, and equality issues. Therefore, I suggest that the Australian scheme, if cost-effective, should represent a model for other countries to follow. Nonetheless, although I endorse this scheme, I will also argue that this kind of scheme raises issues of justice in regard to the distribution of organs. Thus, I propose that other policies would be needed to supplement the scheme in order to guarantee not only a higher number of organs available, but also a fair distribution. © 2014 John Wiley & Sons Ltd.

Exploiting PV technology for basic need provision in Nigeria

International Nuclear Information System (INIS)

Gyoh, L.; Gyoh, S.

2004-01-01

Transitional economies are confronted with ever declining standard of living and low per capita income. Development institutions around the world have come to realize the strategic importance of Sustainable Energy as a Basic Need in the development process. Despite the efforts made by emerging democracies to eradicate poverty, there are still millions of people without access to electricity. Unreliable energy supply currently presents a constant obstacle to many poverty alleviation programmes. Against this background, some states government in Nigeria are exploiting the unique advantage offered by PV technology in the provision of Basic Needs. This study appraises some of the scheme in which the authors have been heavily involved with. This paper identifies some of the strategic policies that might accelerate the successful implementation of PV technology as a poverty alleviation tool in terms of electricity provision in transitional economies. (authors)

EXPLOITATION OF GRANITE BOULDER

Directory of Open Access Journals (Sweden)

Ivan Cotman

1994-12-01

Full Text Available The processes of forming, petrography, features, properties and exploitation of granite boulders are described. The directional drilling and black powder blasting is the succesful method in exploitation of granite boulders (boulder technology (the paper is published in Croatian.

Parareal algorithms with local time-integrators for time fractional differential equations

Science.gov (United States)

Wu, Shu-Lin; Zhou, Tao

2018-04-01

It is challenge work to design parareal algorithms for time-fractional differential equations due to the historical effect of the fractional operator. A direct extension of the classical parareal method to such equations will lead to unbalance computational time in each process. In this work, we present an efficient parareal iteration scheme to overcome this issue, by adopting two recently developed local time-integrators for time fractional operators. In both approaches, one introduces auxiliary variables to localized the fractional operator. To this end, we propose a new strategy to perform the coarse grid correction so that the auxiliary variables and the solution variable are corrected separately in a mixed pattern. It is shown that the proposed parareal algorithm admits robust rate of convergence. Numerical examples are presented to support our conclusions.

Fractional diffusion models of nonlocal transport

International Nuclear Information System (INIS)

Castillo-Negrete, D. del

2006-01-01

A class of nonlocal models based on the use of fractional derivatives (FDs) is proposed to describe nondiffusive transport in magnetically confined plasmas. FDs are integro-differential operators that incorporate in a unified framework asymmetric non-Fickian transport, non-Markovian ('memory') effects, and nondiffusive scaling. To overcome the limitations of fractional models in unbounded domains, we use regularized FDs that allow the incorporation of finite-size domain effects, boundary conditions, and variable diffusivities. We present an α-weighted explicit/implicit numerical integration scheme based on the Grunwald-Letnikov representation of the regularized fractional diffusion operator in flux conserving form. In sharp contrast with the standard diffusive model, the strong nonlocality of fractional diffusion leads to a linear in time response for a decaying pulse at short times. In addition, an anomalous fractional pinch is observed, accompanied by the development of an uphill transport region where the 'effective' diffusivity becomes negative. The fractional flux is in general asymmetric and, for steady states, it has a negative (toward the core) component that enhances confinement and a positive component that increases toward the edge and leads to poor confinement. The model exhibits the characteristic anomalous scaling of the confinement time, τ, with the system's size, L, τ∼L α , of low-confinement mode plasma where 1<α<2 is the order of the FD operator. Numerical solutions of the model with an off-axis source show that the fractional inward transport gives rise to profile peaking reminiscent of what is observed in tokamak discharges with auxiliary off-axis heating. Also, cold-pulse perturbations to steady sates in the model exhibit fast, nondiffusive propagation phenomena that resemble perturbative experiments

Generalized Second-Order Parametric Optimality Conditions in Semiinfinite Discrete Minmax Fractional Programming and Second-Order Univexity

Directory of Open Access Journals (Sweden)

Ram Verma

2016-02-01

Full Text Available This paper deals with mainly establishing numerous sets of generalized second order paramertic sufficient optimality conditions for a semiinfinite discrete minmax fractional programming problem, while the results on semiinfinite discrete minmax fractional programming problem achieved based on some partitioning schemes under various types of generalized second order univexity assumptions. 

A 2D multi-term time and space fractional Bloch-Torrey model based on bilinear rectangular finite elements

Science.gov (United States)

Qin, Shanlin; Liu, Fawang; Turner, Ian W.

2018-03-01

The consideration of diffusion processes in magnetic resonance imaging (MRI) signal attenuation is classically described by the Bloch-Torrey equation. However, many recent works highlight the distinct deviation in MRI signal decay due to anomalous diffusion, which motivates the fractional order generalization of the Bloch-Torrey equation. In this work, we study the two-dimensional multi-term time and space fractional diffusion equation generalized from the time and space fractional Bloch-Torrey equation. By using the Galerkin finite element method with a structured mesh consisting of rectangular elements to discretize in space and the L1 approximation of the Caputo fractional derivative in time, a fully discrete numerical scheme is derived. A rigorous analysis of stability and error estimation is provided. Numerical experiments in the square and L-shaped domains are performed to give an insight into the efficiency and reliability of our method. Then the scheme is applied to solve the multi-term time and space fractional Bloch-Torrey equation, which shows that the extra time derivative terms impact the relaxation process.

A numerical solution for a class of time fractional diffusion equations with delay

Directory of Open Access Journals (Sweden)

Pimenov Vladimir G.

2017-09-01

Full Text Available This paper describes a numerical scheme for a class of fractional diffusion equations with fixed time delay. The study focuses on the uniqueness, convergence and stability of the resulting numerical solution by means of the discrete energy method. The derivation of a linearized difference scheme with convergence order O(τ2−α+ h4 in L∞-norm is the main purpose of this study. Numerical experiments are carried out to support the obtained theoretical results.

A positive and entropy-satisfying finite volume scheme for the Baer–Nunziato model

Energy Technology Data Exchange (ETDEWEB)

Coquel, Frédéric, E-mail: frederic.coquel@cmap.polytechnique.fr [CMAP, École Polytechnique CNRS, UMR 7641, Route de Saclay, F-91128 Palaiseau cedex (France); Hérard, Jean-Marc, E-mail: jean-marc.herard@edf.fr [EDF-R& D, Département MFEE, 6 Quai Watier, F-78401 Chatou Cedex (France); Saleh, Khaled, E-mail: saleh@math.univ-lyon1.fr [Université de Lyon, CNRS UMR 5208, Université Lyon 1, Institut Camille Jordan, 43 bd 11 novembre 1918, F-69622 Villeurbanne cedex (France)

2017-02-01

We present a relaxation scheme for approximating the entropy dissipating weak solutions of the Baer–Nunziato two-phase flow model. This relaxation scheme is straightforwardly obtained as an extension of the relaxation scheme designed in for the isentropic Baer–Nunziato model and consequently inherits its main properties. To our knowledge, this is the only existing scheme for which the approximated phase fractions, phase densities and phase internal energies are proven to remain positive without any restrictive condition other than a classical fully computable CFL condition. For ideal gas and stiffened gas equations of state, real values of the phasic speeds of sound are also proven to be maintained by the numerical scheme. It is also the only scheme for which a discrete entropy inequality is proven, under a CFL condition derived from the natural sub-characteristic condition associated with the relaxation approximation. This last property, which ensures the non-linear stability of the numerical method, is satisfied for any admissible equation of state. We provide a numerical study for the convergence of the approximate solutions towards some exact Riemann solutions. The numerical simulations show that the relaxation scheme compares well with two of the most popular existing schemes available for the Baer–Nunziato model, namely Schwendeman–Wahle–Kapila's Godunov-type scheme and Tokareva–Toro's HLLC scheme . The relaxation scheme also shows a higher precision and a lower computational cost (for comparable accuracy) than a standard numerical scheme used in the nuclear industry, namely Rusanov's scheme. Finally, we assess the good behavior of the scheme when approximating vanishing phase solutions.

Efficient Scheme for Chemical Flooding Simulation

Directory of Open Access Journals (Sweden)

Braconnier Benjamin

2014-07-01

Full Text Available In this paper, we investigate an efficient implicit scheme for the numerical simulation of chemical enhanced oil recovery technique for oil fields. For the sake of brevity, we only focus on flows with polymer to describe the physical and numerical models. In this framework, we consider a black oil model upgraded with the polymer modeling. We assume the polymer only transported in the water phase or adsorbed on the rock following a Langmuir isotherm. The polymer reduces the water phase mobility which can change drastically the behavior of water oil interfaces. Then, we propose a fractional step technique to resolve implicitly the system. The first step is devoted to the resolution of the black oil subsystem and the second to the polymer mass conservation. In such a way, jacobian matrices coming from the implicit formulation have a moderate size and preserve solvers efficiency. Nevertheless, the coupling between the black-oil subsystem and the polymer is not fully resolved. For efficiency and accuracy comparison, we propose an explicit scheme for the polymer for which large time step is prohibited due to its CFL (Courant-Friedrichs-Levy criterion and consequently approximates accurately the coupling. Numerical experiments with polymer are simulated : a core flood, a 5-spot reservoir with surfactant and ions and a 3D real case. Comparisons are performed between the polymer explicit and implicit scheme. They prove that our polymer implicit scheme is efficient, robust and resolves accurately the coupling physics. The development and the simulations have been performed with the software PumaFlow [PumaFlow (2013 Reference manual, release V600, Beicip Franlab].

Influence of Fractionation Scheme and Tumor Location on Toxicities After Stereotactic Body Radiation Therapy for Large (≥5 cm) Non-Small Cell Lung Cancer: A Multi-institutional Analysis

Energy Technology Data Exchange (ETDEWEB)

Verma, Vivek [Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska (United States); Shostrom, Valerie K. [Department of Biostatistics, College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska (United States); Zhen, Weining; Zhang, Mutian [Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska (United States); Braunstein, Steve E. [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Holland, John [Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon (United States); Hallemeier, Christopher L. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Harkenrider, Matthew M. [Department of Radiation Oncology, Loyola University Stritch School of Medicine, Maywood, Illinois (United States); Iskhanian, Adrian [Department of Radiation Oncology, University of Miami Sylvester Comprehensive Cancer Center, Miami, Florida (United States); Jabbour, Salma K. [Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey (United States); Attia, Albert [Department of Radiation Oncology, Vanderbilt University School of Medicine, Nashville, Tennessee (United States); Lee, Percy [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California (United States); Wang, Kyle [Department of Radiation Oncology, University of North Carolina School of Medicine, Chapel Hill, North Carolina (United States); Decker, Roy H. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); McGarry, Ronald C. [Department of Radiation Oncology, University of Kentucky, Lexington, Kentucky (United States); Simone, Charles B., E-mail: charlessimone@umm.edu [Department of Radiation Oncology, University of Maryland Medical Center, Baltimore, Maryland (United States)

2017-03-15

Purpose: To describe the impact of fractionation scheme and tumor location on toxicities in stereotactic body radiation therapy (SBRT) for ≥5-cm non-small cell lung cancer (NSCLC), as part of a multi-institutional analysis. Methods: Patients with primary ≥5-cm N0 M0 NSCLC who underwent ≤5-fraction SBRT were examined across multiple high-volume SBRT centers. Collected data included clinical/treatment parameters; toxicities were prospectively assessed at each institution according to the Common Terminology Criteria for Adverse Events. Patients treated daily were compared with those treated every other day (QOD)/other nondaily regimens. Stratification between central and peripheral tumors was also performed. Results: Ninety-two patients from 12 institutions were evaluated (2004-2016), with median follow-up of 12 months. In total there were 23 (25%) and 6 (7%) grade ≥2 and grade ≥3 toxicities, respectively. Grades 2 and 3 pulmonary toxicities occurred in 9% and 4%, respectively; 1 patient treated daily experienced grade 5 radiation pneumonitis. Of the entire cohort, 46 patients underwent daily SBRT, and 46 received QOD (n=40)/other nondaily (n=6) regimens. Clinical/treatment parameters were similar between groups; the QOD/other group was more likely to receive 3-/4-fraction schemas. Patients treated QOD/other experienced significantly fewer grade ≥2 toxicities as compared with daily treatment (7% vs 43%, P<.001). Patients treated daily also had higher rates of grade ≥2 pulmonary toxicities (P=.014). Patients with peripheral tumors (n=66) were more likely to receive 3-/4-fraction regimens than those with central tumors (n=26). No significant differences in grade ≥2 toxicities were identified according to tumor location (P>.05). Conclusions: From this multi-institutional study, toxicity of SBRT for ≥5-cm lesions is acceptable, and daily treatment was associated with a higher rate of toxicities.

LDPC product coding scheme with extrinsic information for bit patterned media recoding

Science.gov (United States)

Jeong, Seongkwon; Lee, Jaejin

2017-05-01

Since the density limit of the current perpendicular magnetic storage system will soon be reached, bit patterned media recording (BPMR) is a promising candidate for the next generation storage system to achieve an areal density beyond 1 Tb/in2. Each recording bit is stored in a fabricated magnetic island and the space between the magnetic islands is nonmagnetic in BPMR. To approach recording densities of 1 Tb/in2, the spacing of the magnetic islands must be less than 25 nm. Consequently, severe inter-symbol interference (ISI) and inter-track interference (ITI) occur. ITI and ISI degrade the performance of BPMR. In this paper, we propose a low-density parity check (LDPC) product coding scheme that exploits extrinsic information for BPMR. This scheme shows an improved bit error rate performance compared to that in which one LDPC code is used.

An integration scheme for stiff solid-gas reactor models

Directory of Open Access Journals (Sweden)

Bjarne A. Foss

2001-04-01

Full Text Available Many dynamic models encounter numerical integration problems because of a large span in the dynamic modes. In this paper we develop a numerical integration scheme for systems that include a gas phase, and solid and liquid phases, such as a gas-solid reactor. The method is based on neglecting fast dynamic modes and exploiting the structure of the algebraic equations. The integration method is suitable for a large class of industrially relevant systems. The methodology has proven remarkably efficient. It has in practice performed excellent and been a key factor for the success of the industrial simulator for electrochemical furnaces for ferro-alloy production.

A matrix-free, implicit, incompressible fractional-step algorithm for fluid–structure interaction applications

CSIR Research Space (South Africa)

Oxtoby, Oliver F

2012-05-01

Full Text Available In this paper we detail a fast, fully-coupled, partitioned fluid–structure interaction (FSI) scheme. For the incompressible fluid, new fractional-step algorithms are proposed which make possible the fully implicit, but matrixfree, parallel solution...

A Diagnostic PDF Cloud Scheme to Improve Subtropical Low Clouds in NCAR Community Atmosphere Model (CAM5)

Science.gov (United States)

Qin, Yi; Lin, Yanluan; Xu, Shiming; Ma, Hsi-Yen; Xie, Shaocheng

2018-02-01

Low clouds strongly impact the radiation budget of the climate system, but their simulation in most GCMs has remained a challenge, especially over the subtropical stratocumulus region. Assuming a Gaussian distribution for the subgrid-scale total water and liquid water potential temperature, a new statistical cloud scheme is proposed and tested in NCAR Community Atmospheric Model version 5 (CAM5). The subgrid-scale variance is diagnosed from the turbulent and shallow convective processes in CAM5. The approach is able to maintain the consistency between cloud fraction and cloud condensate and thus alleviates the adjustment needed in the default relative humidity-based cloud fraction scheme. Short-term forecast simulations indicate that low cloud fraction and liquid water content, including their diurnal cycle, are improved due to a proper consideration of subgrid-scale variance over the southeastern Pacific Ocean region. Compared with the default cloud scheme, the new approach produced the mean climate reasonably well with improved shortwave cloud forcing (SWCF) due to more reasonable low cloud fraction and liquid water path over regions with predominant low clouds. Meanwhile, the SWCF bias over the tropical land regions is also alleviated. Furthermore, the simulated marine boundary layer clouds with the new approach extend further offshore and agree better with observations. The new approach is able to obtain the top of atmosphere (TOA) radiation balance with a slightly alleviated double ITCZ problem in preliminary coupled simulations. This study implies that a close coupling of cloud processes with other subgrid-scale physical processes is a promising approach to improve cloud simulations.

Electricity storage using a thermal storage scheme

Energy Technology Data Exchange (ETDEWEB)

White, Alexander, E-mail: ajw36@cam.ac.uk [Hopkinson Laboratory, Cambridge University Engineering Department, Trumpington Street, Cambridge. CB2 1PZ (United Kingdom)

2015-01-22

The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on “sensible heat” storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

Numerical simulation of fractional Cable equation of spiny neuronal dendrites

Directory of Open Access Journals (Sweden)

N.H. Sweilam

2014-03-01

Full Text Available In this article, numerical study for the fractional Cable equation which is fundamental equations for modeling neuronal dynamics is introduced by using weighted average of finite difference methods. The stability analysis of the proposed methods is given by a recently proposed procedure similar to the standard John von Neumann stability analysis. A simple and an accurate stability criterion valid for different discretization schemes of the fractional derivative and arbitrary weight factor is introduced and checked numerically. Numerical results, figures, and comparisons have been presented to confirm the theoretical results and efficiency of the proposed method.

Exploiting VM/XA

International Nuclear Information System (INIS)

Boeheim, C.

1990-03-01

The Stanford Linear Accelerator Center has recently completed a conversion to IBM's VM/XA SP Release 2 operating system. The primary physics application had been constrained by the previous 16 megabyte memory limit. Work is underway to enable this application to exploit the new features of VM/XA. This paper presents a brief tutorial on how to convert an application to exploit VM/XA and discusses some of the SLAC experiences in doing so. 13 figs

Price Sensitivity of Demand for Prescription Drugs: Exploiting a Regression Kink Design

DEFF Research Database (Denmark)

Simonsen, Marianne; Skipper, Lars; Skipper, Niels

This paper investigates price sensitivity of demand for prescription drugs using drug purchase records for at 20% random sample of the Danish population. We identify price responsiveness by exploiting exogenous variation in prices caused by kinked reimbursement schemes and implement a regression ...... education and income are, however, more responsive to the price. Also, essential drugs that prevent deterioration in health and prolong life have lower associated average price sensitivity....... kink design. Thus, within a unifying framework we uncover price sensitivity for different subpopulations and types of drugs. The results suggest low average price responsiveness with corresponding price elasticities ranging from -0.08 to -0.25, implying that demand is inelastic. Individuals with lower...

Robust fast controller design via nonlinear fractional differential equations.

Science.gov (United States)

Zhou, Xi; Wei, Yiheng; Liang, Shu; Wang, Yong

2017-07-01

A new method for linear system controller design is proposed whereby the closed-loop system achieves both robustness and fast response. The robustness performance considered here means the damping ratio of closed-loop system can keep its desired value under system parameter perturbation, while the fast response, represented by rise time of system output, can be improved by tuning the controller parameter. We exploit techniques from both the nonlinear systems control and the fractional order systems control to derive a novel nonlinear fractional order controller. For theoretical analysis of the closed-loop system performance, two comparison theorems are developed for a class of fractional differential equations. Moreover, the rise time of the closed-loop system can be estimated, which facilitates our controller design to satisfy the fast response performance and maintain the robustness. Finally, numerical examples are given to illustrate the effectiveness of our methods. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme

Directory of Open Access Journals (Sweden)

Wang Daoshun

2010-01-01

Full Text Available Abstract Traditional Secret Sharing (SS schemes reconstruct secret exactly the same as the original one but involve complex computation. Visual Secret Sharing (VSS schemes decode the secret without computation, but each share is m times as big as the original and the quality of the reconstructed secret image is reduced. Probabilistic visual secret sharing (Prob.VSS schemes for a binary image use only one subpixel to share the secret image; however the probability of white pixels in a white area is higher than that in a black area in the reconstructed secret image. SS schemes, VSS schemes, and Prob. VSS schemes have various construction methods and advantages. This paper first presents an approach to convert (transform a -SS scheme to a -VSS scheme for greyscale images. The generation of the shadow images (shares is based on Boolean XOR operation. The secret image can be reconstructed directly by performing Boolean OR operation, as in most conventional VSS schemes. Its pixel expansion is significantly smaller than that of VSS schemes. The quality of the reconstructed images, measured by average contrast, is the same as VSS schemes. Then a novel matrix-concatenation approach is used to extend the greyscale -SS scheme to a more general case of greyscale -VSS scheme.

Building fast well-balanced two-stage numerical schemes for a model of two-phase flows

Science.gov (United States)

Thanh, Mai Duc

2014-06-01

We present a set of well-balanced two-stage schemes for an isentropic model of two-phase flows arisen from the modeling of deflagration-to-detonation transition in granular materials. The first stage is to absorb the source term in nonconservative form into equilibria. Then in the second stage, these equilibria will be composed into a numerical flux formed by using a convex combination of the numerical flux of a stable Lax-Friedrichs-type scheme and the one of a higher-order Richtmyer-type scheme. Numerical schemes constructed in such a way are expected to get the interesting property: they are fast and stable. Tests show that the method works out until the parameter takes on the value CFL, and so any value of the parameter between zero and this value is expected to work as well. All the schemes in this family are shown to capture stationary waves and preserves the positivity of the volume fractions. The special values of the parameter 0,1/2,1/(1+CFL), and CFL in this family define the Lax-Friedrichs-type, FAST1, FAST2, and FAST3 schemes, respectively. These schemes are shown to give a desirable accuracy. The errors and the CPU time of these schemes and the Roe-type scheme are calculated and compared. The constructed schemes are shown to be well-balanced and faster than the Roe-type scheme.

Exclusive radiotherapy and concurrent endocrine therapy for the management of elderly breast cancer patients: Case study and review of hypo-fractionated schemes; Hormonoradiotherapie exclusive dans la prise en charge du cancer du sein de la personne agee: cas clinique et revue de la litterature des schemas hypofractionnes

Energy Technology Data Exchange (ETDEWEB)

Auberdiac, P.; Cartier, L.; Malkoun, N.; Chauleur, C.; De Laroche, G.; Magne, N. [Departement de radiotherapie, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France); Chargari, C. [Service d' oncologie radiotherapie, hopital d' instruction des armees du Val-de-Grace, 74, boulevard de Port-Royal, 75230 Paris cedex 5 (France); Melis, A.; Jacquin, J.P. [Departement d' oncologie medicale, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France)

2011-12-15

Normo-fractionated radiotherapy is standard for adjuvant management of patients treated with breast conservative surgery for breast cancer. However, many elderly patients are not eligible to such strategy, either because of concurrent diseases, or because the tumor is inoperable. Several protocols of exclusive radiotherapy have been reported in the literature, frequently using hypo-fractionated radiotherapy and endocrine therapy. We report a case of a patient treated with exclusive endocrine and radiotherapy and address the state of the art on hypo-fractionated schemes for the management of elderly breast cancer patients. While hypo-fractionated radiotherapy does not compromise the oncologic or cosmetic outcome, there is no prospective data that assesses the place of radiotherapy for the exclusive treatment of elderly patients. This strategy should be further assessed in clinical randomized trial. (authors)

The economics of exploiting gas hydrates

International Nuclear Information System (INIS)

Döpke, Lena-Katharina; Requate, Till

2014-01-01

We investigate the optimal exploitation of methane hydrates, a recent discovery of methane resources under the sea floor, mainly located along the continental margins. Combustion of methane (releasing CO2) and leakage through blow-outs (releasing CH4) contribute to the accumulation of greenhouse gases. A second externality arises since removing solid gas hydrates from the sea bottom destabilizes continental margins and thus increases the risk of marine earthquakes. We show that in such a model three regimes can occur: i) resource exploitation will be stopped in finite time, and some of the resource will stay in situ, ii) the resource will be used up completely in finite time, and iii) the resource will be exhausted in infinite time. We also show how to internalize the externalities by policy instruments. - Highlights: • We set up a model of optimal has hydrate exploitation • We incorporate to types of damages: contribution to global warming and geo-hazards • We characterize optimal exploitation paths and study decentralization with an exploitation tax. • Three regimes can occur: • i) exploitation in finite time and some of the stock remaining in situ, • ii) exploitation in finite time and the resource will be exhausted, • iii) exploitation and exhaustion in infinite time

Analysis of the Properties of Current Penalty Schemes for Violations of Antitrust Law

NARCIS (Netherlands)

Motchenkova, E.; Kort, P.M.

2004-01-01

The main feature of the penalty schemes described in current sentencing guidelines is that the fine is based on the accumulated gains from cartel or price-fixing activities for the firm.These gains are usually difficult to estimate, but they can be approximated by a fraction of the turnover.The

Influence of Fractionation Scheme and Tumor Location on Toxicities After Stereotactic Body Radiation Therapy for Large (≥5 cm) Non-Small Cell Lung Cancer: A Multi-institutional Analysis.

Science.gov (United States)

Verma, Vivek; Shostrom, Valerie K; Zhen, Weining; Zhang, Mutian; Braunstein, Steve E; Holland, John; Hallemeier, Christopher L; Harkenrider, Matthew M; Iskhanian, Adrian; Jabbour, Salma K; Attia, Albert; Lee, Percy; Wang, Kyle; Decker, Roy H; McGarry, Ronald C; Simone, Charles B

2017-03-15

To describe the impact of fractionation scheme and tumor location on toxicities in stereotactic body radiation therapy (SBRT) for ≥5-cm non-small cell lung cancer (NSCLC), as part of a multi-institutional analysis. Patients with primary ≥5-cm N0 M0 NSCLC who underwent ≤5-fraction SBRT were examined across multiple high-volume SBRT centers. Collected data included clinical/treatment parameters; toxicities were prospectively assessed at each institution according to the Common Terminology Criteria for Adverse Events. Patients treated daily were compared with those treated every other day (QOD)/other nondaily regimens. Stratification between central and peripheral tumors was also performed. Ninety-two patients from 12 institutions were evaluated (2004-2016), with median follow-up of 12 months. In total there were 23 (25%) and 6 (7%) grade ≥2 and grade ≥3 toxicities, respectively. Grades 2 and 3 pulmonary toxicities occurred in 9% and 4%, respectively; 1 patient treated daily experienced grade 5 radiation pneumonitis. Of the entire cohort, 46 patients underwent daily SBRT, and 46 received QOD (n=40)/other nondaily (n=6) regimens. Clinical/treatment parameters were similar between groups; the QOD/other group was more likely to receive 3-/4-fraction schemas. Patients treated QOD/other experienced significantly fewer grade ≥2 toxicities as compared with daily treatment (7% vs 43%, Plocation (P>.05). From this multi-institutional study, toxicity of SBRT for ≥5-cm lesions is acceptable, and daily treatment was associated with a higher rate of toxicities. Copyright © 2016 Elsevier Inc. All rights reserved.

Low-Feedback Opportunistic Scheduling Schemes for Wireless Networks with Heterogenous Users

KAUST Repository

Rashid, Faraan

2012-07-01

Efficient implementation of resource sharing strategies in a multi-user wireless environment can improve the performance of a network significantly. In this thesis we study various scheduling strategies for wireless networks and handle the problem of opportunistically scheduling transmissions using channel aware schemes. First we propose a scheme that can handle users with asymmetric channel conditions and is opportunistic in the sense that it exploits the multi-user diversity of the network. The scheme requires the users to have a priori knowledge of their channel distributions. The associated overhead is limited meaning it offers reduced feedback load, that does not scale with the increasing number of users. The main technique used to shrink the feedback load is the contention based distributed implementation of a splitting algorithm that does not require explicit feedback to the scheduler from every user. The users find the best among themselves, in a distributed manner, while requiring just a ternary broadcast feedback from the scheduler at the end of each mini-slot. In addition, it can also handle fairness constraints in time and throughput to various degrees. Next we propose another opportunistic scheduler that offers most of the benefits of the previously proposed scheme but is more practical because it can also handle heterogenous users whose channel distributions are unknown. This new scheme actually reduces the complexity and is also more robust for changing traffic patterns. Finally we extend both these schemes to the scenario where there are fixed thresholds, this enables us to handle opportunistic scheduling in practical systems that can only transmit over finite number of discrete rates with the additional benefit that full feedback session, even from the selected user, is never required.

Wilson expansion in the minimal subtraction scheme

International Nuclear Information System (INIS)

Smirnov, V.A.

1989-01-01

The small distance expansion of the product of composite fields is constructed for an arbitrary renormalization procedure of the type of minimal subtraction scheme. Coefficient functions of the expansion are expressed explicitly through the Green functions of composite fields. The expansion has the explicity finite form: the ultraviolet (UV) divergences of the coefficient functions and composite fields are removed by the initial renormalization procedure while the infrared (IR) divergences in massless diagrams with nonvanishing contribution into the coefficient functions are removed by the R-operation which is the IR part of the R-operation. The latter is the generalization of the dimensional renormalization in the case when both UV and IR divergences are present. To derive the expansion, a ''pre-subtracting operator'' is introduced and formulas of the counter-term technique are exploited

Assessment of heavy metal removal technologies for biowaste by physico-chemical fractionation

NARCIS (Netherlands)

Veeken, A.H.M.; Hamelers, H.V.M.

2003-01-01

In the Netherlands, the heavy metal content of biowaste-compost frequently exceeds the legal standards for heavy metals. In order to assess heavy metal removal technologies, a physico-chemical fractionation scheme was developed to gain insight into the distribution of heavy metals (Cd, Cu, Pb and

Exploiting geo-distributed clouds for a e-health monitoring system with minimum service delay and privacy preservation.

Science.gov (United States)

Shen, Qinghua; Liang, Xiaohui; Shen, Xuemin; Lin, Xiaodong; Luo, Henry Y

2014-03-01

In this paper, we propose an e-health monitoring system with minimum service delay and privacy preservation by exploiting geo-distributed clouds. In the system, the resource allocation scheme enables the distributed cloud servers to cooperatively assign the servers to the requested users under the load balance condition. Thus, the service delay for users is minimized. In addition, a traffic-shaping algorithm is proposed. The traffic-shaping algorithm converts the user health data traffic to the nonhealth data traffic such that the capability of traffic analysis attacks is largely reduced. Through the numerical analysis, we show the efficiency of the proposed traffic-shaping algorithm in terms of service delay and privacy preservation. Furthermore, through the simulations, we demonstrate that the proposed resource allocation scheme significantly reduces the service delay compared to two other alternatives using jointly the short queue and distributed control law.

Exploitation in International Paid Surrogacy Arrangements

OpenAIRE

Wilkinson, Stephen

2015-01-01

Abstract Many critics have suggested that international paid surrogacy is exploitative. Taking such concerns as its starting point, this article asks: (1) how defensible is the claim that international paid surrogacy is exploitative and what could be done to make it less exploitative? (2) In the light of the answer to (1), how strong is the case for prohibiting it? Exploitation could in principle be dealt with by improving surrogates' pay and conditions. However, doing so may exacerbate probl...

Hypo fractionated conformal irradiation of patients with malignant glioma

International Nuclear Information System (INIS)

Aboziada, M.A.; Abo-Kresha, A.E.

2012-01-01

Purpose: The aim of the study is to evaluate the effect of a conformal irradiation in short fractionation scheme of 49.5 Gy in 15 fractions in an overall time of 3 weeks, in terms of overall survival (OAS) and progression free survival (PFS) rates in brain glioma patients. Patients and methods: A prospective study was conducted on 54 brain glioma patients and was carried out in the Radiation Oncology Department, South Egypt Cancer Institute, Assiut University during the period from April 2006 till June 2009. Patients were treated by hypo fractionated conformal irradiation (49.5 Gy/15 fractions/3 weeks). Results: The median follow up was 23 months (range: 9-39 months). Two-year OAS and PFS rates were 68% and 60%, respectively. In univariate analysis, age > 50 years, poor performance status [Karnofasky score of >40- 50 years and glioblastoma pathology were the only independent prognostic factors that were associated with poor OAS (p = 0.003 and p = 0.004, respectively), and PFS (p = 0.027 and p = 0.011, respectively). Conclusion: Hypo fractionated conformal radiotherapy was as effective as the conventional radiotherapy, with time sparing for patients, and for radiation oncology centers. Hypo fractionated radiotherapy may be considered the radiotherapy regimen of choice in clinical practice for patients with gliomas

Towards Efficient Energy Management of Smart Buildings Exploiting Heuristic Optimization with Real Time and Critical Peak Pricing Schemes

Directory of Open Access Journals (Sweden)

Sheraz Aslam

2017-12-01

Full Text Available The smart grid plays a vital role in decreasing electricity cost through Demand Side Management (DSM. Smart homes, a part of the smart grid, contribute greatly to minimizing electricity consumption cost via scheduling home appliances. However, user waiting time increases due to the scheduling of home appliances. This scheduling problem is the motivation to find an optimal solution that could minimize the electricity cost and Peak to Average Ratio (PAR with minimum user waiting time. There are many studies on Home Energy Management (HEM for cost minimization and peak load reduction. However, none of the systems gave sufficient attention to tackle multiple parameters (i.e., electricity cost and peak load reduction at the same time as user waiting time was minimum for residential consumers with multiple homes. Hence, in this work, we propose an efficient HEM scheme using the well-known meta-heuristic Genetic Algorithm (GA, the recently developed Cuckoo Search Optimization Algorithm (CSOA and the Crow Search Algorithm (CSA, which can be used for electricity cost and peak load alleviation with minimum user waiting time. The integration of a smart Electricity Storage System (ESS is also taken into account for more efficient operation of the Home Energy Management System (HEMS. Furthermore, we took the real-time electricity consumption pattern for every residence, i.e., every home has its own living pattern. The proposed scheme is implemented in a smart building; comprised of thirty smart homes (apartments, Real-Time Pricing (RTP and Critical Peak Pricing (CPP signals are examined in terms of electricity cost estimation for both a single smart home and a smart building. In addition, feasible regions are presented for single and multiple smart homes, which show the relationship among the electricity cost, electricity consumption and user waiting time. Experimental results demonstrate the effectiveness of our proposed scheme for single and multiple smart

Discrete random walk models for space-time fractional diffusion

International Nuclear Information System (INIS)

Gorenflo, Rudolf; Mainardi, Francesco; Moretti, Daniele; Pagnini, Gianni; Paradisi, Paolo

2002-01-01

A physical-mathematical approach to anomalous diffusion may be based on generalized diffusion equations (containing derivatives of fractional order in space or/and time) and related random walk models. By space-time fractional diffusion equation we mean an evolution equation obtained from the standard linear diffusion equation by replacing the second-order space derivative with a Riesz-Feller derivative of order α is part of (0,2] and skewness θ (moduleθ≤{α,2-α}), and the first-order time derivative with a Caputo derivative of order β is part of (0,1]. Such evolution equation implies for the flux a fractional Fick's law which accounts for spatial and temporal non-locality. The fundamental solution (for the Cauchy problem) of the fractional diffusion equation can be interpreted as a probability density evolving in time of a peculiar self-similar stochastic process that we view as a generalized diffusion process. By adopting appropriate finite-difference schemes of solution, we generate models of random walk discrete in space and time suitable for simulating random variables whose spatial probability density evolves in time according to this fractional diffusion equation

Bit-level quantum color image encryption scheme with quantum cross-exchange operation and hyper-chaotic system

Science.gov (United States)

Zhou, Nanrun; Chen, Weiwei; Yan, Xinyu; Wang, Yunqian

2018-06-01

In order to obtain higher encryption efficiency, a bit-level quantum color image encryption scheme by exploiting quantum cross-exchange operation and a 5D hyper-chaotic system is designed. Additionally, to enhance the scrambling effect, the quantum channel swapping operation is employed to swap the gray values of corresponding pixels. The proposed color image encryption algorithm has larger key space and higher security since the 5D hyper-chaotic system has more complex dynamic behavior, better randomness and unpredictability than those based on low-dimensional hyper-chaotic systems. Simulations and theoretical analyses demonstrate that the presented bit-level quantum color image encryption scheme outperforms its classical counterparts in efficiency and security.

Functional fractional calculus for system identification and controls

CERN Document Server

Das, Shantanu

2008-01-01

This work is inspired by thought to have an overall fuel-ef?cient nuclear plant control system. I picked up the topic in 2002 while deriving the reactor control laws, which aimed at fuel ef?ciency. Controlling the nuclear reactor close to its natural behavior by concept of exponent shape governor, ratio control and use of logarithmic logic, aims at the fuel ef?ciency. The power-maneuvering trajectory is obtained by shaped-normalized-period function, and this de?nes the road map on which the reactor should be governed. The experience of this concept governing the Atomic Power Plant of Tarapur Atomic Power Station gives lesser overall gains compared to the older plants, where conventional proportional integral and deri- tive type (PID) scheme is employed. Therefore, this motivation led to design the scheme for control system than the conventional schemes to aim at overall plant ef?ciency. Thus, I felt the need to look beyondPID and obtained the answer in fr- tional order control system, requiring fractional cal...

Profits and Exploitation: A Reappraisal

OpenAIRE

Yoshihara, Naoki; Veneziani, Roberto

2011-01-01

This paper provides a mathematical analysis of the Marxian theory of the exploitation of labour in general equilibrium models. The two main definitions of Marxian exploitation in the literature, proposed by Morishima (1974) and Roemer (1982), respectively, are analysed in the context of general convex economies. It is shown that, contrary to the received view, in general these definitions do not preserve the so-called Fundamental Marxian Theorem (FMT), which states that the exploitation of la...

A unitary ESPRIT scheme of joint angle estimation for MOTS MIMO radar.

Science.gov (United States)

Wen, Chao; Shi, Guangming

2014-08-07

The transmit array of multi-overlapped-transmit-subarray configured bistatic multiple-input multiple-output (MOTS MIMO) radar is partitioned into a number of overlapped subarrays, which is different from the traditional bistatic MIMO radar. In this paper, a new unitary ESPRIT scheme for joint estimation of the direction of departure (DOD) and the direction of arrival (DOA) for MOTS MIMO radar is proposed. In our method, each overlapped-transmit-subarray (OTS) with the identical effective aperture is regarded as a transmit element and the characteristics that the phase delays between the two OTSs is utilized. First, the measurements corresponding to all the OTSs are partitioned into two groups which have a rotational invariance relationship with each other. Then, the properties of centro-Hermitian matrices and real-valued rotational invariance factors are exploited to double the measurement samples and reduce computational complexity. Finally, the close-formed solution of automatically paired DOAs and DODs of targets is derived in a new manner. The proposed scheme provides increased estimation accuracy with the combination of inherent advantages of MOTS MIMO radar with unitary ESPRIT. Simulation results are presented to demonstrate the effectiveness and advantage of the proposed scheme.

Absorbed fractions for alpha particles in ellipsoidal volumes

International Nuclear Information System (INIS)

Amato, Ernesto; Baldari, Sergio; Italiano, Antonio

2013-01-01

Internal dosimetry of alpha particles is gaining attention due to the increasing applications in cancer treatment and also for the assessment of environmental contamination from radionuclides. We developed a Monte Carlo simulation in GEANT4 in order to calculate the absorbed fractions for monoenergetic alpha particles in the energy interval between 0.1 and 10 MeV, uniformly distributed in ellipsoids made of soft tissue. For each volume, we simulated a spherical shape, three oblate and three prolate ellipsoids, and one scalene shape. For each energy and for every geometrical configuration, an analytical relationship between the absorbed fraction and a ‘generalized radius’ was found; and the dependence of the fit parameters on the alpha energy is discussed and fitted by parametric functions. With the proposed formulation, the absorbed fraction for alpha particles in the energy range explored can be calculated for volumes and for ellipsoidal shapes of practical interest. This method can be applied to the evaluation of absorbed fraction from alpha-emitting radionuclides. The contribution to the deposited energy coming from electron and photon emissions can be accounted for exploiting the specific formulations previously introduced. As an example of application, the dosimetry of 213 Bi and its decay chain in ellipsoids is reported. (paper)

LDPC product coding scheme with extrinsic information for bit patterned media recoding

Directory of Open Access Journals (Sweden)

Seongkwon Jeong

2017-05-01

Full Text Available Since the density limit of the current perpendicular magnetic storage system will soon be reached, bit patterned media recording (BPMR is a promising candidate for the next generation storage system to achieve an areal density beyond 1 Tb/in2. Each recording bit is stored in a fabricated magnetic island and the space between the magnetic islands is nonmagnetic in BPMR. To approach recording densities of 1 Tb/in2, the spacing of the magnetic islands must be less than 25 nm. Consequently, severe inter-symbol interference (ISI and inter-track interference (ITI occur. ITI and ISI degrade the performance of BPMR. In this paper, we propose a low-density parity check (LDPC product coding scheme that exploits extrinsic information for BPMR. This scheme shows an improved bit error rate performance compared to that in which one LDPC code is used.

Image communication scheme based on dynamic visual cryptography and computer generated holography

Science.gov (United States)

Palevicius, Paulius; Ragulskis, Minvydas

2015-01-01

Computer generated holograms are often exploited to implement optical encryption schemes. This paper proposes the integration of dynamic visual cryptography (an optical technique based on the interplay of visual cryptography and time-averaging geometric moiré) with Gerchberg-Saxton algorithm. A stochastic moiré grating is used to embed the secret into a single cover image. The secret can be visually decoded by a naked eye if only the amplitude of harmonic oscillations corresponds to an accurately preselected value. The proposed visual image encryption scheme is based on computer generated holography, optical time-averaging moiré and principles of dynamic visual cryptography. Dynamic visual cryptography is used both for the initial encryption of the secret image and for the final decryption. Phase data of the encrypted image are computed by using Gerchberg-Saxton algorithm. The optical image is decrypted using the computationally reconstructed field of amplitudes.

Fractional-calculus-based FDTD algorithm for ultrawideband electromagnetic characterization of arbitrary dispersive dielectric materials

NARCIS (Netherlands)

Caratelli, Diego; Mescia, Luciano; Bia, Pietro; Stukach, Oleg V.

2016-01-01

A novel finite-difference time-domain algorithm for modeling ultrawideband electromagnetic pulse propagation in arbitrary multirelaxed dispersive media is presented. The proposed scheme is based on a general, yet computationally efficient, series representation of the fractional derivative operators

Optical movie encryption based on a discrete multiple-parameter fractional Fourier transform

International Nuclear Information System (INIS)

Zhong, Zhi; Zhang, Yujie; Shan, Mingguang; Wang, Ying; Zhang, Yabin; Xie, Hong

2014-01-01

A movie encryption scheme is proposed using a discrete multiple-parameter fractional Fourier transform and theta modulation. After being modulated by sinusoidal amplitude grating, each frame of the movie is transformed by a filtering procedure and then multiplexed into a complex signal. The complex signal is multiplied by a pixel scrambling operation and random phase mask, and then encrypted by a discrete multiple-parameter fractional Fourier transform. The movie can be retrieved by using the correct keys, such as a random phase mask, a pixel scrambling operation, the parameters in a discrete multiple-parameter fractional Fourier transform and a time sequence. Numerical simulations have been performed to demonstrate the validity and the security of the proposed method. (paper)

Chaos in the fractional order logistic delay system: Circuit realization and synchronization

International Nuclear Information System (INIS)

Baskonus, Haci Mehmet; Hammouch, Zakia; Mekkaoui, Toufik; Bulut, Hasan

2016-01-01

In this paper, we present a numerical study and a circuit design to prove existence of chaos in the fractional order Logistic delay system. In addition, we investigate an active control synchronization scheme in this system. Numerical and cicruit simulations show the effectiveness and feasibility of this method.

Continuous fractional-order Zero Phase Error Tracking Control.

Science.gov (United States)

Liu, Lu; Tian, Siyuan; Xue, Dingyu; Zhang, Tao; Chen, YangQuan

2018-04-01

A continuous time fractional-order feedforward control algorithm for tracking desired time varying input signals is proposed in this paper. The presented controller cancels the phase shift caused by the zeros and poles of controlled closed-loop fractional-order system, so it is called Fractional-Order Zero Phase Tracking Controller (FZPETC). The controlled systems are divided into two categories i.e. with and without non-cancellable (non-minimum-phase) zeros which stand in unstable region or on stability boundary. Each kinds of systems has a targeted FZPETC design control strategy. The improved tracking performance has been evaluated successfully by applying the proposed controller to three different kinds of fractional-order controlled systems. Besides, a modified quasi-perfect tracking scheme is presented for those systems which may not have available future tracking trajectory information or have problem in high frequency disturbance rejection if the perfect tracking algorithm is applied. A simulation comparison and a hardware-in-the-loop thermal peltier platform are shown to validate the practicality of the proposed quasi-perfect control algorithm. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Redefining Exploitation

DEFF Research Database (Denmark)

Agarwala, Rina

2016-01-01

This article examines how self-employed workers are organizing in the garments and waste collection industries in India. Although the question of who is profiting from self-employed workers’ labor is complex, the cases outlined in this paper highlight telling instances of how some self......-employed workers are organizing as workers. They are fighting labor exploitation by redefining the concept to include additional exploitation axes (from the state and middle class) and forms (including sexual). In doing so, they are redefining potential solutions, including identities and material benefits, to fit...... their unique needs. By expanding the category of “workers” beyond those defined by a narrow focus on a standard employer-employee relationship, these movements are also fighting exclusion from earlier labor protections by increasing the number of entitled beneficiaries. These struggles provide an important...

Numerical Solution of Time-Dependent Problems with a Fractional-Power Elliptic Operator

Science.gov (United States)

Vabishchevich, P. N.

2018-03-01

A time-dependent problem in a bounded domain for a fractional diffusion equation is considered. The first-order evolution equation involves a fractional-power second-order elliptic operator with Robin boundary conditions. A finite-element spatial approximation with an additive approximation of the operator of the problem is used. The time approximation is based on a vector scheme. The transition to a new time level is ensured by solving a sequence of standard elliptic boundary value problems. Numerical results obtained for a two-dimensional model problem are presented.

Performance evaluation of modulation and multiple access schemes in ultraviolet optical wireless connections for two atmosphere thickness cases.

Science.gov (United States)

Raptis, Nikos; Pikasis, Evangelos; Syvridis, Dimitris

2016-08-01

The exploitation of optical wireless communication channels in a non-line-of-sight regime is studied for point-to-point and networking configurations considering the use of light-emitting diodes. Two environments with different scattering center densities are considered, assuming operation at 265 nm. The bit error rate performance of both pulsed and multicarrier modulation schemes is examined, using numerical approaches. In the networking scenario, a central node only receives data, one node transmits useful data, and the rest of them act as interferers. The performance of the desirable node's transmissions is evaluated. The access to the medium is controlled by a code division multiple access scheme.

Boundedness of the solutions for certain classes of fractional differential equations with application to adaptive systems.

Science.gov (United States)

Aguila-Camacho, Norelys; Duarte-Mermoud, Manuel A

2016-01-01

This paper presents the analysis of three classes of fractional differential equations appearing in the field of fractional adaptive systems, for the case when the fractional order is in the interval α ∈(0,1] and the Caputo definition for fractional derivatives is used. The boundedness of the solutions is proved for all three cases, and the convergence to zero of the mean value of one of the variables is also proved. Applications of the obtained results to fractional adaptive schemes in the context of identification and control problems are presented at the end of the paper, including numerical simulations which support the analytical results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Computational Challenge of Fractional Differential Equations and the Potential Solutions: A Survey

Directory of Open Access Journals (Sweden)

Chunye Gong

2015-01-01

Full Text Available We present a survey of fractional differential equations and in particular of the computational cost for their numerical solutions from the view of computer science. The computational complexities of time fractional, space fractional, and space-time fractional equations are O(N2M, O(NM2, and O(NM(M + N compared with O(MN for the classical partial differential equations with finite difference methods, where M, N are the number of space grid points and time steps. The potential solutions for this challenge include, but are not limited to, parallel computing, memory access optimization (fractional precomputing operator, short memory principle, fast Fourier transform (FFT based solutions, alternating direction implicit method, multigrid method, and preconditioner technology. The relationships of these solutions for both space fractional derivative and time fractional derivative are discussed. The authors pointed out that the technologies of parallel computing should be regarded as a basic method to overcome this challenge, and some attention should be paid to the fractional killer applications, high performance iteration methods, high order schemes, and Monte Carlo methods. Since the computation of fractional equations with high dimension and variable order is even heavier, the researchers from the area of mathematics and computer science have opportunity to invent cornerstones in the area of fractional calculus.

Schemes of radioactive decay, its interpretations in the scope of the radiological protection

International Nuclear Information System (INIS)

Mohamad, N.; Caro, R.A.; Bergoc, R.M.

1998-01-01

Full text: In our teaching experience we have verified that the interpretation of the symbols of radioactive decay schemes is one of the most difficult subject in the study of radioisotope methodologies for almost all professionals, and specially for those who have no solid background in mathematics or physics. The correct interpretation of decay schemes has fundamental importance for the proper election of measurement conditions and for performing the dosimetric and shielding calculations. Nuclides employed in Nuclear Medicine and Biomedicine are beta, gamma or beta/gamma emitters. Interpretation of decay schemes of beta emitters, by β + , β - or electronic capture are not difficult. In gamma emitting nuclides it is frequent that a particular level of energy is de-excited through more than one gamma transition of a given percentage and energy. On the other hand, it is also frequent that conversion electrons are emitted together with gamma photons, the proportion of which is usually given as the conversion factor, e/γ. The fraction of emitted photons is calculated as: 1 / [1+ (e/γ)], whereas the fraction of emitted conversion electrons is equal to: (e/γ) / [1+ (e/γ)]. Special attention should be given to the post-accommodation mechanism after disintegration in which orbital vacancies are produced: electron conversion or electron capture, in which the emission of X-rays and Auger electrons occur. All this information should be taken into account for the correct choice of measurement conditions, as well as internal and external dose calculations. In the present work we describe the analysis and interpretation of disintegration schemes in general and that of the most employed nuclides in Nuclear Medicine and Biomedicine. (author) [es

Predicting the benefit of binaural cue preservation in bilateral directional processing schemes for listeners with impaired hearing

DEFF Research Database (Denmark)

Brand, Thomas; Hauth, Christopher; Wagener, Kirsten C.

2018-01-01

Linked pairs of hearing aids offer various possibilities for directional processing providing adjustable trade-off between improving signal-to-noise ratio and preserving binaural listening. The benefit depends on the processing scheme, the acoustic scenario, and the listener’s ability to exploit...... fine structure. BSIM revealed a benefit due to binaural processing in well-performing listeners when processing provided low-frequency interaural timing cues....

Hypofractionation results in reduced tumor cell kill compared to conventional fractionation for tumors with regions of hypoxia.

Science.gov (United States)

Carlson, David J; Keall, Paul J; Loo, Billy W; Chen, Zhe J; Brown, J Martin

2011-03-15

Tumor hypoxia has been observed in many human cancers and is associated with treatment failure in radiation therapy. The purpose of this study is to quantify the effect of different radiation fractionation schemes on tumor cell killing, assuming a realistic distribution of tumor oxygenation. A probability density function for the partial pressure of oxygen in a tumor cell population is quantified as a function of radial distance from the capillary wall. Corresponding hypoxia reduction factors for cell killing are determined. The surviving fraction of a tumor consisting of maximally resistant cells, cells at intermediate levels of hypoxia, and normoxic cells is calculated as a function of dose per fraction for an equivalent tumor biological effective dose under normoxic conditions. Increasing hypoxia as a function of distance from blood vessels results in a decrease in tumor cell killing for a typical radiotherapy fractionation scheme by a factor of 10(5) over a distance of 130 μm. For head-and-neck cancer and prostate cancer, the fraction of tumor clonogens killed over a full treatment course decreases by up to a factor of ∼10(3) as the dose per fraction is increased from 2 to 24 Gy and from 2 to 18 Gy, respectively. Hypofractionation of a radiotherapy regimen can result in a significant decrease in tumor cell killing compared to standard fractionation as a result of tumor hypoxia. There is a potential for large errors when calculating alternate fractionations using formalisms that do not account for tumor hypoxia. Copyright © 2011 Elsevier Inc. All rights reserved.

On the welfare properties of fractional reserve banking

OpenAIRE

Sanches, Daniel R.

2015-01-01

Supersedes Working Paper 13-32/R. Monetary economists have long recognized a tension between the benefits of fractional reserve banking, such as the ability to undertake more profitable (long-term) investment opportunities, and the difficulties associated with it, such as the risk of in-solvency for each bank and the associated losses to bank liability holders. I show that a specific banking arrangement (a joint-liability scheme) provides an effective mechanism for ensuring the ex-post transf...

Distributed Sleep Scheduling in Wireless Sensor Networks via Fractional Domatic Partitioning

Science.gov (United States)

Schumacher, André; Haanpää, Harri

We consider setting up sleep scheduling in sensor networks. We formulate the problem as an instance of the fractional domatic partition problem and obtain a distributed approximation algorithm by applying linear programming approximation techniques. Our algorithm is an application of the Garg-Könemann (GK) scheme that requires solving an instance of the minimum weight dominating set (MWDS) problem as a subroutine. Our two main contributions are a distributed implementation of the GK scheme for the sleep-scheduling problem and a novel asynchronous distributed algorithm for approximating MWDS based on a primal-dual analysis of Chvátal's set-cover algorithm. We evaluate our algorithm with ns2 simulations.

DNA evidence of bowhead whale exploitation by Greenlandic Paleo-Inuit 4,000 years ago

Science.gov (United States)

Seersholm, Frederik Valeur; Pedersen, Mikkel Winther; Søe, Martin Jensen; Shokry, Hussein; Mak, Sarah Siu Tze; Ruter, Anthony; Raghavan, Maanasa; Fitzhugh, William; Kjær, Kurt H.; Willerslev, Eske; Meldgaard, Morten; Kapel, Christian M. O.; Hansen, Anders Johannes

2016-11-01

The demographic history of Greenland is characterized by recurrent migrations and extinctions since the first humans arrived 4,500 years ago. Our current understanding of these extinct cultures relies primarily on preserved fossils found in their archaeological deposits, which hold valuable information on past subsistence practices. However, some exploited taxa, though economically important, comprise only a small fraction of these sub-fossil assemblages. Here we reconstruct a comprehensive record of past subsistence economies in Greenland by sequencing ancient DNA from four well-described midden deposits. Our results confirm that the species found in the fossil record, like harp seal and ringed seal, were a vital part of Inuit subsistence, but also add a new dimension with evidence that caribou, walrus and whale species played a more prominent role for the survival of Paleo-Inuit cultures than previously reported. Most notably, we report evidence of bowhead whale exploitation by the Saqqaq culture 4,000 years ago.

Hypericin photocytotoxicyty followed after fractionated light irradiation

International Nuclear Information System (INIS)

Sackova, V.; Kulikova, L.; Mikes, J.; Kleban, J.; Fedorocko, P.

2006-01-01

The present study demonstrates the in vitro effect of hypericin-mediated photodynamic therapy with fractionated light delivery. Cells were photosensitized with unequal light fractions separated by dark intervals (1 h, 6 h). The changes in survival, apoptosis and cell cycle were compared on HT-29 cells irradiated with a single light dose (12 J/cm 2 ) to the fractionated light delivery (1+11 J/cm 2 ) 24 h and 48 h after photodynamic treatment. It was found that a fractionated light regime with a longer dark period resulted in a decrease of hypericin photo-cytotoxicity. Cell survival was higher after light sensitization with a 6 h dark interval. DNA fragmentation occurred after a single light dose application, but in contrast no apoptotic DNA formation was detected with a 6 h dark pause. After fractionation the percentage of cells in G 1 phase of the cell cycle was increased, while the proportion of cells in the G 2 phase decreased as compared to a single light dose application i. e. both percentage of cells in G 1 and G 2 phase of cell cycle were near control levels. We presume that the longer dark interval after the irradiation of cells by first light dose makes them to resistant to the effect of the second illumination. These findings confirm that the light application scheme together with other photodynamic protocol components is crucial for the photo-cytotoxicity of hypericin. (authors)

Exploiting the Error-Correcting Capabilities of Low Density Parity Check Codes in Distributed Video Coding using Optical Flow

DEFF Research Database (Denmark)

Rakêt, Lars Lau; Søgaard, Jacob; Salmistraro, Matteo

2012-01-01

We consider Distributed Video Coding (DVC) in presence of communication errors. First, we present DVC side information generation based on a new method of optical flow driven frame interpolation, where a highly optimized TV-L1 algorithm is used for the flow calculations and combine three flows....... Thereafter methods for exploiting the error-correcting capabilities of the LDPCA code in DVC are investigated. The proposed frame interpolation includes a symmetric flow constraint to the standard forward-backward frame interpolation scheme, which improves quality and handling of large motion. The three...... flows are combined in one solution. The proposed frame interpolation method consistently outperforms an overlapped block motion compensation scheme and a previous TV-L1 optical flow frame interpolation method with an average PSNR improvement of 1.3 dB and 2.3 dB respectively. For a GOP size of 2...

Genetic progress in multistage dairy cattle breeding schemes using genetic markers.

Science.gov (United States)

Schrooten, C; Bovenhuis, H; van Arendonk, J A M; Bijma, P

2005-04-01

The aim of this paper was to explore general characteristics of multistage breeding schemes and to evaluate multistage dairy cattle breeding schemes that use information on quantitative trait loci (QTL). Evaluation was either for additional genetic response or for reduction in number of progeny-tested bulls while maintaining the same response. The reduction in response in multistage breeding schemes relative to comparable single-stage breeding schemes (i.e., with the same overall selection intensity and the same amount of information in the final stage of selection) depended on the overall selection intensity, the selection intensity in the various stages of the breeding scheme, and the ratio of the accuracies of selection in the various stages of the breeding scheme. When overall selection intensity was constant, reduction in response increased with increasing selection intensity in the first stage. The decrease in response was highest in schemes with lower overall selection intensity. Reduction in response was limited in schemes with low to average emphasis on first-stage selection, especially if the accuracy of selection in the first stage was relatively high compared with the accuracy in the final stage. Closed nucleus breeding schemes in dairy cattle that use information on QTL were evaluated by deterministic simulation. In the base scheme, the selection index consisted of pedigree information and own performance (dams), or pedigree information and performance of 100 daughters (sires). In alternative breeding schemes, information on a QTL was accounted for by simulating an additional index trait. The fraction of the variance explained by the QTL determined the correlation between the additional index trait and the breeding goal trait. Response in progeny test schemes relative to a base breeding scheme without QTL information ranged from +4.5% (QTL explaining 5% of the additive genetic variance) to +21.2% (QTL explaining 50% of the additive genetic variance). A

Exploration, Exploitation, and Organizational Coordination Mechanisms

Directory of Open Access Journals (Sweden)

Silvio Popadiuk

2016-03-01

Full Text Available This paper presents an empirical relationship among exploration, exploitation, and organizational coordination mechanisms, classified as the centralization of decision-making, formalization, and connectedness. In order to analyze the findings of this survey, we used two techniques: Principal Component Analysis (PCA and Partial Least Squares Path Modeling (PLS-PM. Our analysis was supported by 249 answers from managers of companies located in Brazil (convenience sampling. Contrary to expectations, centralization and exploitation were negatively associated. Our data supports the research hypothesis that formalization is positively associated with exploitation. Although the relationship between formalization and exploration were significant, the result is contrary to the research hypothesis that we made. The relationships among connectedness and exploitation, and connectedness and exploration were both positive and significant. This relationship means that the more connectedness increases, the higher the likelihood of exploitation and exploration.

Progress Toward Steady State Tokamak Operation Exploiting the high bootstrap current fraction regime

Science.gov (United States)

Ren, Q.

2015-11-01

Recent DIII-D experiments have advanced the normalized fusion performance of the high bootstrap current fraction tokamak regime toward reactor-relevant steady state operation. The experiments, conducted by a joint team of researchers from the DIII-D and EAST tokamaks, developed a fully noninductive scenario that could be extended on EAST to a demonstration of long pulse steady-state tokamak operation. Fully noninductive plasmas with extremely high values of the poloidal beta, βp >= 4 , have been sustained at βT >= 2 % for long durations with excellent energy confinement quality (H98y,2 >= 1 . 5) and internal transport barriers (ITBs) generated at large minor radius (>= 0 . 6) in all channels (Te, Ti, ne, VTf). Large bootstrap fraction (fBS ~ 80 %) has been obtained with high βp. ITBs have been shown to be compatible with steady state operation. Because of the unusually large ITB radius, normalized pressure is not limited to low βN values by internal ITB-driven modes. βN up to ~4.3 has been obtained by optimizing the plasma-wall distance. The scenario is robust against several variations, including replacing some on-axis with off-axis neutral beam injection (NBI), adding electron cyclotron (EC) heating, and reducing the NBI torque by a factor of 2. This latter observation is particularly promising for extension of the scenario to EAST, where maximum power is obtained with balanced NBI injection, and to a reactor, expected to have low rotation. However, modeling of this regime has provided new challenges to state-of-the-art modeling capabilities: quasilinear models can dramatically underpredict the electron transport, and the Sauter bootstrap current can be insufficient. The analysis shows first-principle NEO is in good agreement with experiments for the bootstrap current calculation and ETG modes with a larger saturated amplitude or EM modes may provide the missing electron transport. Work supported in part by the US DOE under DE-FC02-04ER54698, DE-AC52-07NA

Efficient Resource Allocation and Sectorization for Fractional Frequency Reuse (FFR in LTE Femtocell Systems

Directory of Open Access Journals (Sweden)

M. T. Kawser

2015-12-01

Full Text Available The Fractional Frequency Reuse (FFR is a resource allocation technique that can effectively mitigate inter-cell interference (ICI in LTE based HetNets and it is a promising solution. Various FFR schemes have been suggested to address the challenge of interference in femtocell systems. In this paper, we study the scopes of interference mitigation and capacity improvement. We propose a resource allocation scheme that gradually varies frequency resource share with distance from the eNodeB for both macrocells and femtocells in order to attain better utilization of the resources. This is performed effectively using three layers in the cell. The proposal also employs high number sectors in a cell, low interference and good frequency reuse. Monte-Carlo simulations are performed, which show that the proposed scheme achieves significantly better throughput compared to the existing FFR schemes.

An automated multi-scale network-based scheme for detection and location of seismic sources

Science.gov (United States)

Poiata, N.; Aden-Antoniow, F.; Satriano, C.; Bernard, P.; Vilotte, J. P.; Obara, K.

2017-12-01

We present a recently developed method - BackTrackBB (Poiata et al. 2016) - allowing to image energy radiation from different seismic sources (e.g., earthquakes, LFEs, tremors) in different tectonic environments using continuous seismic records. The method exploits multi-scale frequency-selective coherence in the wave field, recorded by regional seismic networks or local arrays. The detection and location scheme is based on space-time reconstruction of the seismic sources through an imaging function built from the sum of station-pair time-delay likelihood functions, projected onto theoretical 3D time-delay grids. This imaging function is interpreted as the location likelihood of the seismic source. A signal pre-processing step constructs a multi-band statistical representation of the non stationary signal, i.e. time series, by means of higher-order statistics or energy envelope characteristic functions. Such signal-processing is designed to detect in time signal transients - of different scales and a priori unknown predominant frequency - potentially associated with a variety of sources (e.g., earthquakes, LFE, tremors), and to improve the performance and the robustness of the detection-and-location location step. The initial detection-location, based on a single phase analysis with the P- or S-phase only, can then be improved recursively in a station selection scheme. This scheme - exploiting the 3-component records - makes use of P- and S-phase characteristic functions, extracted after a polarization analysis of the event waveforms, and combines the single phase imaging functions with the S-P differential imaging functions. The performance of the method is demonstrated here in different tectonic environments: (1) analysis of the one year long precursory phase of 2014 Iquique earthquake in Chile; (2) detection and location of tectonic tremor sources and low-frequency earthquakes during the multiple episodes of tectonic tremor activity in southwestern Japan.

SU-F-T-497: Spatiotemporally Optimal, Personalized Prescription Scheme for Glioblastoma Patients Using the Proliferation and Invasion Glioma Model

Energy Technology Data Exchange (ETDEWEB)

Kim, M; Rockhill, J; Phillips, M [University Washington, Seattle, WA (United States)

2016-06-15

Purpose: To investigate a spatiotemporally optimal radiotherapy prescription scheme and its potential benefit for glioblastoma (GBM) patients using the proliferation and invasion (PI) glioma model. Methods: Standard prescription for GBM was assumed to deliver 46Gy in 23 fractions to GTV1+2cm margin and additional 14Gy in 7 fractions to GTV2+2cm margin. We simulated the tumor proliferation and invasion in 2D according to the PI glioma model with a moving velocity of 0.029(slow-move), 0.079(average-move), and 0.13(fast-move) mm/day for GTV2 with a radius of 1 and 2cm. For each tumor, the margin around GTV1 and GTV2 was varied to 0–6 cm and 1–3 cm respectively. Total dose to GTV1 was constrained such that the equivalent uniform dose (EUD) to normal brain equals EUD with the standard prescription. A non-stationary dose policy, where the fractional dose varies, was investigated to estimate the temporal effect of the radiation dose. The efficacy of an optimal prescription scheme was evaluated by tumor cell-surviving fraction (SF), EUD, and the expected survival time. Results: Optimal prescription for the slow-move tumors was to use 3.0(small)-3.5(large) cm margins to GTV1, and 1.5cm margin to GTV2. For the average- and fast-move tumors, it was optimal to use 6.0cm margin for GTV1 suggesting that whole brain therapy is optimal, and then 1.5cm (average-move) and 1.5–3.0cm (fast-move, small-large) margins for GTV2. It was optimal to deliver the boost sequentially using a linearly decreasing fractional dose for all tumors. Optimal prescription led to 0.001–0.465% of the tumor SF resulted from using the standard prescription, and increased tumor EUD by 25.3–49.3% and the estimated survival time by 7.6–22.2 months. Conclusion: It is feasible to optimize a prescription scheme depending on the individual tumor characteristics. A personalized prescription scheme could potentially increase tumor EUD and the expected survival time significantly without increasing EUD to

Process of 3D wireless decentralized sensor deployment using parsing crossover scheme

Directory of Open Access Journals (Sweden)

Albert H.R. Ko

2015-07-01

Full Text Available A Wireless Sensor Networks (WSN usually consists of numerous wireless devices deployed in a region of interest, each able to collect and process environmental information and communicate with neighboring devices. It can thus be regarded as a Multi-Agent System for territorial security, where individual agents cooperate with each other to avoid duplication of effort and to exploit other agent’s capacities. The problem of sensor deployment becomes non-trivial when we consider environmental factors, such as terrain elevations. Due to the fact that all sensors are homogeneous, the chromosomes that encode sensor positions are actually interchangeable, and conventional crossover schemes such as uniform crossover would cause some redundancy as well as over-concentration in certain specific geographical area. We propose a Parsing Crossover Scheme that intends to reduce redundancy and ease geographical concentration pattern in an effort to facilitate the search. The proposed parsing crossover method demonstrates better performances than those of uniform crossover under different terrain irregularities.

Auction dynamics: A volume constrained MBO scheme

Science.gov (United States)

Jacobs, Matt; Merkurjev, Ekaterina; Esedoǧlu, Selim

2018-02-01

We show how auction algorithms, originally developed for the assignment problem, can be utilized in Merriman, Bence, and Osher's threshold dynamics scheme to simulate multi-phase motion by mean curvature in the presence of equality and inequality volume constraints on the individual phases. The resulting algorithms are highly efficient and robust, and can be used in simulations ranging from minimal partition problems in Euclidean space to semi-supervised machine learning via clustering on graphs. In the case of the latter application, numerous experimental results on benchmark machine learning datasets show that our approach exceeds the performance of current state-of-the-art methods, while requiring a fraction of the computation time.

Beam dynamics analysis of dielectric laser acceleration using a fast 6D tracking scheme

Directory of Open Access Journals (Sweden)

Uwe Niedermayer

2017-11-01

Full Text Available A six-dimensional symplectic tracking approach exploiting the periodicity properties of dielectric laser acceleration (DLA gratings is presented. The longitudinal kick is obtained from the spatial Fourier harmonics of the laser field within the structure, and the transverse kicks are obtained using the Panofsky-Wenzel theorem. Additionally to the usual, strictly longitudinally periodic gratings, our approach is also applicable to periodicity chirped (subrelativistic and tilted (deflection gratings. In the limit of small kicks and short periods we obtain the 6D Hamiltonian, which allows, for example, to obtain matched beam distributions in DLAs. The scheme is applied to beam and grating parameters similar to recently performed experiments. The paper concludes with an outlook to laser based focusing schemes, which are promising to overcome fundamental interaction length limitations, in order to build an entire microchip-sized laser driven accelerator.

Strong Maximum Principle for Multi-Term Time-Fractional Diffusion Equations and its Application to an Inverse Source Problem

OpenAIRE

Liu, Yikan

2015-01-01

In this paper, we establish a strong maximum principle for fractional diffusion equations with multiple Caputo derivatives in time, and investigate a related inverse problem of practical importance. Exploiting the solution properties and the involved multinomial Mittag-Leffler functions, we improve the weak maximum principle for the multi-term time-fractional diffusion equation to a stronger one, which is parallel to that for its single-term counterpart as expected. As a direct application, w...

A QR code based zero-watermarking scheme for authentication of medical images in teleradiology cloud.

Science.gov (United States)

Seenivasagam, V; Velumani, R

2013-01-01

Healthcare institutions adapt cloud based archiving of medical images and patient records to share them efficiently. Controlled access to these records and authentication of images must be enforced to mitigate fraudulent activities and medical errors. This paper presents a zero-watermarking scheme implemented in the composite Contourlet Transform (CT)-Singular Value Decomposition (SVD) domain for unambiguous authentication of medical images. Further, a framework is proposed for accessing patient records based on the watermarking scheme. The patient identification details and a link to patient data encoded into a Quick Response (QR) code serves as the watermark. In the proposed scheme, the medical image is not subjected to degradations due to watermarking. Patient authentication and authorized access to patient data are realized on combining a Secret Share with the Master Share constructed from invariant features of the medical image. The Hu's invariant image moments are exploited in creating the Master Share. The proposed system is evaluated with Checkmark software and is found to be robust to both geometric and non geometric attacks.

A QR Code Based Zero-Watermarking Scheme for Authentication of Medical Images in Teleradiology Cloud

Directory of Open Access Journals (Sweden)

V. Seenivasagam

2013-01-01

Full Text Available Healthcare institutions adapt cloud based archiving of medical images and patient records to share them efficiently. Controlled access to these records and authentication of images must be enforced to mitigate fraudulent activities and medical errors. This paper presents a zero-watermarking scheme implemented in the composite Contourlet Transform (CT—Singular Value Decomposition (SVD domain for unambiguous authentication of medical images. Further, a framework is proposed for accessing patient records based on the watermarking scheme. The patient identification details and a link to patient data encoded into a Quick Response (QR code serves as the watermark. In the proposed scheme, the medical image is not subjected to degradations due to watermarking. Patient authentication and authorized access to patient data are realized on combining a Secret Share with the Master Share constructed from invariant features of the medical image. The Hu’s invariant image moments are exploited in creating the Master Share. The proposed system is evaluated with Checkmark software and is found to be robust to both geometric and non geometric attacks.

Technical Note: Adjoint formulation of the TOMCAT atmospheric transport scheme in the Eulerian backtracking framework (RETRO-TOM)

Science.gov (United States)

Haines, P. E.; Esler, J. G.; Carver, G. D.

2014-06-01

A new methodology for the formulation of an adjoint to the transport component of the chemistry transport model TOMCAT is described and implemented in a new model, RETRO-TOM. The Eulerian backtracking method is used, allowing the forward advection scheme (Prather's second-order moments) to be efficiently exploited in the backward adjoint calculations. Prather's scheme is shown to be time symmetric, suggesting the possibility of high accuracy. To attain this accuracy, however, it is necessary to make a careful treatment of the "density inconsistency" problem inherent to offline transport models. The results are verified using a series of test experiments. These demonstrate the high accuracy of RETRO-TOM when compared with direct forward sensitivity calculations, at least for problems in which flux limiters in the advection scheme are not required. RETRO-TOM therefore combines the flexibility and stability of a "finite difference of adjoint" formulation with the accuracy of an "adjoint of finite difference" formulation.

Characteristics of organic phosphorus fractions in different trophic sediments of lakes from the middle and lower reaches of Yangtze River region and Southwestern Plateau, China

International Nuclear Information System (INIS)

Zhang Runyu; Wu Fengchang; Liu Congqiang; Fu Pingqing; Li Wen; Wang Liying; Liao Haiqing; Guo Jianyang

2008-01-01

In this study, the characteristics of organic phosphorus (P o ) fractions in sediments of six lakes from the middle and lower reaches of Yangtze River region and Southwestern China Plateau, China were investigated using a soil P o fractionation scheme, and the relationships between P o , inorganic phosphorus (P i ) and pollution status were also discussed. The results show that the rank order of P o fractions was: residual P o > HCl-P o > fulvic acid-P > humic acid-P > NaHCO 3 -P o , with their average relative proportion 8.7:4.6:3.2:2.1:1.0. P o fractions, especially nonlabile P o , were significantly correlated with organic matter, P o and NaOH-P i . Different distribution patterns of P fractions were observed in those two different regions. P o fractions in the heavily polluted sediments were higher than those in moderately and no polluted sediments, it is suggested that P o should be paid more attention in the lake eutrophication investigation. - Organic phosphorus fractions in sediments from 6 different trophic Chinese lakes were characterized using an improved fractionation scheme

On the optimum joint decoding capacity of wyner circular GCMAC by exploiting hadamard inequality

KAUST Repository

Shakir, Muhammad

2010-09-01

This paper presents an original expression of the theoretical upper bound for the optimum joint decoding capacity of Wyner Circular Gaussian Cellular Multiple Access Channel (C-GCMAC). This upper bound is a novel application of the Hadamard inequality established by exploiting the Hadamard operation between the channel fading (G) and channel slow gain (Ω) matrices. This paper demonstrates that the theoretical upper bound converges to the actual capacity for negligible channel slow gain among the mobile terminals and the base stations for the entire range of Signal to Noise Ratios (SNRs). The behaviour of the theoretical bound is critically observed when the intercell and the intra-cell time sharing schemes are employed. © 2010 IEEE.

Exploiting the Capture Effect to Enhance RACH Performance in Cellular-Based M2M Communications

Directory of Open Access Journals (Sweden)

Jonghun Kim

2017-09-01

Full Text Available Cellular-based machine-to-machine (M2M communication is expected to facilitate services for the Internet of Things (IoT. However, because cellular networks are designed for human users, they have some limitations. Random access channel (RACH congestion caused by massive access from M2M devices is one of the biggest factors hindering cellular-based M2M services because the RACH congestion causes random access (RA throughput degradation and connection failures to the devices. In this paper, we show the possibility exploiting the capture effects, which have been known to have a positive impact on the wireless network system, on RA procedure for improving the RA performance of M2M devices. For this purpose, we analyze an RA procedure using a capture model. Through this analysis, we examine the effects of capture on RA performance and propose an Msg3 power-ramping (Msg3 PR scheme to increase the capture probability (thereby increasing the RA success probability even when severe RACH congestion problem occurs. The proposed analysis models are validated using simulations. The results show that the proposed scheme, with proper parameters, further improves the RA throughput and reduces the connection failure probability, by slightly increasing the energy consumption. Finally, we demonstrate the effects of coexistence with other RA-related schemes through simulation results.

Norm- and hypo-fractionated radiotherapy is capable of activating human dendritic cells.

Science.gov (United States)

Kulzer, Lorenz; Rubner, Yvonne; Deloch, Lisa; Allgäuer, Andrea; Frey, Benjamin; Fietkau, Rainer; Dörrie, Jan; Schaft, Niels; Gaipl, Udo S

2014-10-01

Despite the transient immunosuppressive properties of local radiotherapy (RT), this classical treatment modality of solid tumors is capable of inducing immunostimulatory forms of tumor-cell death. The resulting 'immunotoxicity' in the tumor, but not in healthy tissues, may finally lead to immune-mediated destruction of the tumor. However, little is known about the best irradiation scheme in this setting. This study examines the immunological effects of differently irradiated human colorectal tumor cells on human monocyte-derived dendritic cells (DC). Human SW480 tumor cells were irradiated with a norm-fractionation scheme (5 × 2 Gy), a hypo-fractionated protocol (3 × 5 Gy), and with a high single irradiation dose (radiosurgery; 1 × 15 Gy). Subsequently, human immature DC (iDC) were co-incubated with supernatants (SN) of these differently treated tumor cells. Afterwards, DC were analyzed regarding the expression of maturation markers, the release of cytokines, and the potential to stimulate CD4(+) T-cells. The co-incubation of iDC with SN of tumor cells exposed to norm- or hypo-fractionated RT resulted in a significantly increased secretion of the immune activating cytokines IL-12p70, IL-8, IL-6, and TNFα, compared to iDC co-incubated with SN of tumor cells that received a high single irradiation dose or were not irradiated. In addition, DC-maturation markers CD80, CD83, and CD25 were also exclusively elevated after co-incubation with the SN of fractionated irradiated tumor cells. Furthermore, the SN of tumor cells that were irradiated with norm- or hypo-fractionated RT triggered iDC to stimulate CD4(+) T-cells not only in an allogenic, but also in an antigen-specific manner like mature DC. Collectively, these results demonstrate that norm- and hypo-fractionated RT induces a fast human colorectal tumor-cell death with immunogenic potential that can trigger DC maturation and activation in vitro. Such findings may contribute to the improvement of

A MEPS is a MEPS is a MEPS. Comparing Ecodesign and Top Runner schemes for setting product efficiency standards

Energy Technology Data Exchange (ETDEWEB)

Siderius, P.J.S. [NL Agency, Croeselaan 15, P.O. Box 8242, 3503 RE Utrecht (Netherlands); Nakagami, H. [Jyukankyo Research Institute, 3-29, Kioi-cho, Chiyoda-ku Tokyo, 102-0094 (Japan)

2013-02-15

Both Top Runner in Japan and Ecodesign in the European Union are schemes to set requirements on the energy efficiency (minimum efficiency performance standards, MEPS) of a variety of products. This article provides an overview of the main characteristics and results of both schemes and gives recommendations for improving them. Both schemes contribute significantly to the energy efficiency targets set by the European Commission and the Japanese government. Although it is difficult to compare the absolute levels of the requirements, comparison of the relative improvements and of the savings on household electricity consumption (11 % in Japan, 16 % in the EU) suggest they are in the same range. Furthermore, the time needed to set or review requirements is in both schemes considerable (between 5 and 6 years on average) and the manageability increasingly will become a challenge. The appeal of the Top Runner approach is that the most efficient product (Top Runner) sets the standard for all products at the next target year. Although the Ecodesign scheme includes the elements for a Top Runner approach, it could exploit this principle more explicitly. On the other hand, the Top Runner scheme could benefit by using a real minimum efficiency performance standard instead of a fleet average. This would make the monitoring and enforcement more simple and transparent, and would open the scheme for products where the market situation is less clear.

Fused man-machine classification schemes to enhance diagnosis of breast microcalcifications

International Nuclear Information System (INIS)

Andreadis, Ioannis; Sevastianos, Chatzistergos; Konstantina, Nikita; George, Spyrou

2017-01-01

Computer aided diagnosis (CAD x ) approaches are developed towards the effective discrimination between benign and malignant clusters of microcalcifications. Different sources of information are exploited, such as features extracted from the image analysis of the region of interest, features related to the location of the cluster inside the breast, age of the patient and descriptors provided by the radiologists while performing their diagnostic task. A series of different CAD x schemes are implemented, each of which uses a different category of features and adopts a variety of machine learning algorithms and alternative image processing techniques. A novel framework is introduced where these independent diagnostic components are properly combined according to features critical to a radiologist in an attempt to identify the most appropriate CAD x schemes for the case under consideration. An open access database (Digital Database of Screening Mammography (DDSM)) has been elaborated to construct a large dataset with cases of varying subtlety, in order to ensure the development of schemes with high generalization ability, as well as extensive evaluation of their performance. The obtained results indicate that the proposed framework succeeds in improving the diagnostic procedure, as the achieved overall classification performance outperforms all the independent single diagnostic components, as well as the radiologists that assessed the same cases, in terms of accuracy, sensitivity, specificity and area under the curve following receiver operating characteristic analysis. (paper)

Fused man-machine classification schemes to enhance diagnosis of breast microcalcifications

Science.gov (United States)

Andreadis, Ioannis; Sevastianos, Chatzistergos; George, Spyrou; Konstantina, Nikita

2017-11-01

Computer aided diagnosis (CAD x ) approaches are developed towards the effective discrimination between benign and malignant clusters of microcalcifications. Different sources of information are exploited, such as features extracted from the image analysis of the region of interest, features related to the location of the cluster inside the breast, age of the patient and descriptors provided by the radiologists while performing their diagnostic task. A series of different CAD x schemes are implemented, each of which uses a different category of features and adopts a variety of machine learning algorithms and alternative image processing techniques. A novel framework is introduced where these independent diagnostic components are properly combined according to features critical to a radiologist in an attempt to identify the most appropriate CAD x schemes for the case under consideration. An open access database (Digital Database of Screening Mammography (DDSM)) has been elaborated to construct a large dataset with cases of varying subtlety, in order to ensure the development of schemes with high generalization ability, as well as extensive evaluation of their performance. The obtained results indicate that the proposed framework succeeds in improving the diagnostic procedure, as the achieved overall classification performance outperforms all the independent single diagnostic components, as well as the radiologists that assessed the same cases, in terms of accuracy, sensitivity, specificity and area under the curve following receiver operating characteristic analysis.

Organ sales: exploitative at any price?

Science.gov (United States)

Lawlor, Rob

2014-05-01

In many cases, claims that a transaction is exploitative will focus on the details of the transaction, such as the price paid or conditions. For example, in a claim that a worker is exploited, the grounds for the claim are usually that the pay is not sufficient or the working conditions too dangerous. In some cases, however, the claim that a transaction is exploitative is not seen to rely on these finer details. Many, for example, claim that organ sales would be exploitative, in a way that doesn't seem to depend on the details. This article considers, but ultimately rejects, a number of arguments which could be used to defend this sort of claim. © 2012 John Wiley & Sons Ltd.

Simultaneous quantification of dissolved organic carbon fractions and copper complexation using solid-phase extraction

International Nuclear Information System (INIS)

McElmurry, Shawn P.; Long, David T.; Voice, Thomas C.

2010-01-01

Trace metal cycling in natural waters is highly influenced by the amount and type of dissolved organic C (DOC). Although determining individual species of DOC is unrealistic, there has been success in classifying DOC by determining operationally defined fractions. However, current fractionation schemes do not allow for the simultaneous quantification of associated trace metals. Using operational classifications, a scheme was developed to fractionate DOC based on a set of seven solid-phase extraction (SPE) cartridges. The cartridges isolated fractions based on a range of specific mechanisms thought to be responsible for DOC aggregation in solution, as well as molecular weight. The method was evaluated to determine if it can identify differences in DOC characteristics, including differences in Cu-DOC complexation. Results are that: (1) cartridge blanks were low for both DOC and Cu, (2) differences are observed in the distribution of DOC amongst the fractions from various sources that are consistent with what is known about the DOC materials and the mechanisms operative for each cartridge, (3) when present as a free cation, Cu was not retained by non-cationic cartridges allowing the method to be used to assess Cu binding, (4) the capability of the method to provide quantitative assessment of Cu-DOC complexation was demonstrated for a variety of DOC standards, (5) Cu was found to preferentially bind with high molecular weight fractions of DOC, and (6) estimated partitioning coefficients and conditional binding constants for Cu were similar to those reported elsewhere. The method developed describes DOC characteristics based on specific bonding mechanisms (hydrogen, donor-acceptor, London dispersion, and ionic bonding) while simultaneously quantifying Cu-DOC complexation. The method provides researchers a means of describing not only the extent of DOC complexation but also how that complex will be behave in natural waters.

A Safe Supervisory Flight Control Scheme in the Presence of Constraints and Anomalies

Directory of Open Access Journals (Sweden)

Franzè Giuseppe

2015-03-01

Full Text Available In this paper the hybrid supervisory control architecture developed by Famularo et al. (2011 for constrained control systems is adopted with the aim to improve safety in aircraft operations when critical events like command saturations or unpredicted anomalies occur. The capabilities of a low-computational demanding predictive scheme for the supervision of non-linear dynamical systems subject to sudden switchings amongst operating conditions and time-varying constraints are exploited in the flight control systems framework. The strategy is based on command governor ideas and is tailored to jointly take into account time-varying set-points/constraints. Unpredictable anomalies in the nominal plant behaviour, whose models fall in the category of time-varying constraints, can also be tolerated by the control scheme. In order to show the effectiveness of the proposed approach, simulations both on a high altitude performance demonstrator unmanned aircraft with redundant control surfaces and the P92 general aviation aircraft are discussed.

Finite element formulation of viscoelastic sandwich beams using fractional derivative operators

Science.gov (United States)

Galucio, A. C.; Deü, J.-F.; Ohayon, R.

This paper presents a finite element formulation for transient dynamic analysis of sandwich beams with embedded viscoelastic material using fractional derivative constitutive equations. The sandwich configuration is composed of a viscoelastic core (based on Timoshenko theory) sandwiched between elastic faces (based on Euler-Bernoulli assumptions). The viscoelastic model used to describe the behavior of the core is a four-parameter fractional derivative model. Concerning the parameter identification, a strategy to estimate the fractional order of the time derivative and the relaxation time is outlined. Curve-fitting aspects are focused, showing a good agreement with experimental data. In order to implement the viscoelastic model into the finite element formulation, the Grünwald definition of the fractional operator is employed. To solve the equation of motion, a direct time integration method based on the implicit Newmark scheme is used. One of the particularities of the proposed algorithm lies in the storage of displacement history only, reducing considerably the numerical efforts related to the non-locality of fractional operators. After validations, numerical applications are presented in order to analyze truncation effects (fading memory phenomena) and solution convergence aspects.

Acoustic programming in step-split-flow lateral-transport thin fractionation.

Science.gov (United States)

Ratier, Claire; Hoyos, Mauricio

2010-02-15

We propose a new separation scheme for micrometer-sized particles combining acoustic forces and gravitational field in split-flow lateral-transport thin (SPLITT)-like fractionation channels. Acoustic forces are generated by ultrasonic standing waves set up in the channel thickness. We report on the separation of latex particles of two different sizes in a preliminary experiment using this proposed hydrodynamic acoustic sorter, HAS. Total binary separation of 5 and 10 microm diameter particles has been achieved. Numerical simulations of trajectories of particles flowing through a step-SPLITT under the conditions which combine acoustic standing waves and gravity show a very good agreement with the experiment. Calculations in order to compare separations obtained by the acoustic programming s-SPLITT fractionation and the conventional SPLITT fractionation show that the improvement in separation time is around 1 order of magnitude and could still be improved; this is the major finding of this work. This separation technique can be extended to biomimetic particles and blood cells.

A joint multi-view plus depth image coding scheme based on 3D-warping

DEFF Research Database (Denmark)

Zamarin, Marco; Zanuttigh, Pietro; Milani, Simone

2011-01-01

on the scene structure that can be effectively exploited to improve the performance of multi-view coding schemes. In this paper we introduce a novel coding architecture that replaces the inter-view motion prediction operation with a 3D warping approach based on depth information to improve the coding......Free viewpoint video applications and autostereoscopic displays require the transmission of multiple views of a scene together with depth maps. Current compression and transmission solutions just handle these two data streams as separate entities. However, depth maps contain key information...

Performance of the Goddard multiscale modeling framework with Goddard ice microphysical schemes

Science.gov (United States)

Chern, Jiun-Dar; Tao, Wei-Kuo; Lang, Stephen E.; Matsui, Toshihisa; Li, J.-L. F.; Mohr, Karen I.; Skofronick-Jackson, Gail M.; Peters-Lidard, Christa D.

2016-03-01

The multiscale modeling framework (MMF), which replaces traditional cloud parameterizations with cloud-resolving models (CRMs) within a host atmospheric general circulation model (GCM), has become a new approach for climate modeling. The embedded CRMs make it possible to apply CRM-based cloud microphysics directly within a GCM. However, most such schemes have never been tested in a global environment for long-term climate simulation. The benefits of using an MMF to evaluate rigorously and improve microphysics schemes are here demonstrated. Four one-moment microphysical schemes are implemented into the Goddard MMF and their results validated against three CloudSat/CALIPSO cloud ice products and other satellite data. The new four-class (cloud ice, snow, graupel, and frozen drops/hail) ice scheme produces a better overall spatial distribution of cloud ice amount, total cloud fractions, net radiation, and total cloud radiative forcing than earlier three-class ice schemes, with biases within the observational uncertainties. Sensitivity experiments are conducted to examine the impact of recently upgraded microphysical processes on global hydrometeor distributions. Five processes dominate the global distributions of cloud ice and snow amount in long-term simulations: (1) allowing for ice supersaturation in the saturation adjustment, (2) three additional correction terms in the depositional growth of cloud ice to snow, (3) accounting for cloud ice fall speeds, (4) limiting cloud ice particle size, and (5) new size-mapping schemes for snow and graupel. Despite the cloud microphysics improvements, systematic errors associated with subgrid processes, cyclic lateral boundaries in the embedded CRMs, and momentum transport remain and will require future improvement.

Herbivory eliminates fitness costs of mutualism exploiters.

Science.gov (United States)

Simonsen, Anna K; Stinchcombe, John R

2014-04-01

A common empirical observation in mutualistic interactions is the persistence of variation in partner quality and, in particular, the persistence of exploitative phenotypes. For mutualisms between hosts and symbionts, most mutualism theory assumes that exploiters always impose fitness costs on their host. We exposed legume hosts to mutualistic (nitrogen-fixing) and exploitative (non-nitrogen-fixing) symbiotic rhizobia in field conditions, and manipulated the presence or absence of insect herbivory to determine if the costly fitness effects of exploitative rhizobia are context-dependent. Exploitative rhizobia predictably reduced host fitness when herbivores were excluded. However, insects caused greater damage on hosts associating with mutualistic rhizobia, as a consequence of feeding preferences related to leaf nitrogen content, resulting in the elimination of fitness costs imposed on hosts by exploitative rhizobia. Our experiment shows that herbivory is potentially an important factor in influencing the evolutionary dynamic between legumes and rhizobia. Partner choice and host sanctioning are theoretically predicted to stabilize mutualisms by reducing the frequency of exploitative symbionts. We argue that herbivore pressure may actually weaken selection on choice and sanction mechanisms, thus providing one explanation of why host-based discrimination mechanisms may not be completely effective in eliminating nonbeneficial partners. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

A Practical Scheme for Frequency Offset Estimation in MIMO-OFDM Systems

Directory of Open Access Journals (Sweden)

Morelli Michele

2009-01-01

Full Text Available This paper deals with training-assisted carrier frequency offset (CFO estimation in multiple-input multiple-output (MIMO orthogonal frequency-division multiplexing (OFDM systems. The exact maximum likelihood (ML solution to this problem is computationally demanding as it involves a line search over the CFO uncertainty range. To reduce the system complexity, we divide the CFO into an integer part plus a fractional part and select the pilot subcarriers such that the training sequences have a repetitive structure in the time domain. In this way, the fractional CFO is efficiently computed through a correlation-based approach, while ML methods are employed to estimate the integer CFO. Simulations indicate that the proposed scheme is superior to the existing alternatives in terms of both estimation accuracy and processing load.

A Practical Scheme for Frequency Offset Estimation in MIMO-OFDM Systems

Directory of Open Access Journals (Sweden)

2009-03-01

Full Text Available This paper deals with training-assisted carrier frequency offset (CFO estimation in multiple-input multiple-output (MIMO orthogonal frequency-division multiplexing (OFDM systems. The exact maximum likelihood (ML solution to this problem is computationally demanding as it involves a line search over the CFO uncertainty range. To reduce the system complexity, we divide the CFO into an integer part plus a fractional part and select the pilot subcarriers such that the training sequences have a repetitive structure in the time domain. In this way, the fractional CFO is efficiently computed through a correlation-based approach, while ML methods are employed to estimate the integer CFO. Simulations indicate that the proposed scheme is superior to the existing alternatives in terms of both estimation accuracy and processing load.

Devil’s Vortex Phase Structure as Frequency Plane Mask for Image Encryption Using the Fractional Mellin Transform

Directory of Open Access Journals (Sweden)

Sunanda Vashisth

2014-01-01

Full Text Available A frequency plane phase mask based on Devil’s vortex structure has been used for image encryption using the fractional Mellin transform. The phase key for decryption is obtained by an iterative phase retrieval algorithm. The proposed scheme has been validated for grayscale secret target images, by numerical simulation. The efficacy of the scheme has been evaluated by computing mean-squared-error between the secret target image and the decrypted image. Sensitivity analysis of the decryption process to variations in various encryption parameters has been carried out. The proposed encryption scheme has been seen to exhibit reasonable robustness against occlusion attack.

Exact analysis of Packet Reversed Packet Combining Scheme and Modified Packet Combining Scheme; and a combined scheme

International Nuclear Information System (INIS)

Bhunia, C.T.

2007-07-01

Packet combining scheme is a well defined simple error correction scheme for the detection and correction of errors at the receiver. Although it permits a higher throughput when compared to other basic ARQ protocols, packet combining (PC) scheme fails to correct errors when errors occur in the same bit locations of copies. In a previous work, a scheme known as Packet Reversed Packet Combining (PRPC) Scheme that will correct errors which occur at the same bit location of erroneous copies, was studied however PRPC does not handle a situation where a packet has more than 1 error bit. The Modified Packet Combining (MPC) Scheme that can correct double or higher bit errors was studied elsewhere. Both PRPC and MPC schemes are believed to offer higher throughput in previous studies, however neither adequate investigation nor exact analysis was done to substantiate this claim of higher throughput. In this work, an exact analysis of both PRPC and MPC is carried out and the results reported. A combined protocol (PRPC and MPC) is proposed and the analysis shows that it is capable of offering even higher throughput and better error correction capability at high bit error rate (BER) and larger packet size. (author)

Dissemination and Exploitation Strategy

DEFF Research Database (Denmark)

Badger, Merete; Monaco, Lucio; Fransson, Torsten

of Technology in Sweden, Politecnico di Torino in Italy, and Eindhoven University of Technology in the Netherlands. The project is partially funded by the European Commission under the 7th Framework Programme (project no. RI-283746). This report describes the final dissemination and exploitation strategy...... for project Virtual Campus Hub. A preliminary dissemination and exploitation plan was setup early in the project as described in the deliverable D6.1 Dissemination strategy paper - preliminary version. The plan has been revised on a monthly basis during the project’s lifecycle in connection with the virtual...

Quasi-projective synchronization of fractional-order complex-valued recurrent neural networks.

Science.gov (United States)

Yang, Shuai; Yu, Juan; Hu, Cheng; Jiang, Haijun

2018-08-01

In this paper, without separating the complex-valued neural networks into two real-valued systems, the quasi-projective synchronization of fractional-order complex-valued neural networks is investigated. First, two new fractional-order inequalities are established by using the theory of complex functions, Laplace transform and Mittag-Leffler functions, which generalize traditional inequalities with the first-order derivative in the real domain. Additionally, different from hybrid control schemes given in the previous work concerning the projective synchronization, a simple and linear control strategy is designed in this paper and several criteria are derived to ensure quasi-projective synchronization of the complex-valued neural networks with fractional-order based on the established fractional-order inequalities and the theory of complex functions. Moreover, the error bounds of quasi-projective synchronization are estimated. Especially, some conditions are also presented for the Mittag-Leffler synchronization of the addressed neural networks. Finally, some numerical examples with simulations are provided to show the effectiveness of the derived theoretical results. Copyright © 2018 Elsevier Ltd. All rights reserved.

A novel algorithm for fractional resizing of digital image in DCT domain

Institute of Scientific and Technical Information of China (English)

Wang Ci; Zhang Wenjun; Zheng Meng

2005-01-01

Fractional resizing of digital images is needed in various applications, such as displaying at different resolution depending on that of display device, building image index for an image database, and changing resolution according to the transmission channel bandwidth. With the wide use of JPEG and MPEG, almost all digital images are stored and transferred in DCT compressed format. Inorder to save the computation and memory cost, it is desirable to do resizing in DCT domain directly. This paper presents a fast and efficient method, which possesses the capability of fractional resizing in DCT domain. Experimental results confirm that this scheme can achieve significant computation cost reduction while maintain better quality.

Formalization of hydrocarbon conversion scheme of catalytic cracking for mathematical model development

Science.gov (United States)

Nazarova, G.; Ivashkina, E.; Ivanchina, E.; Kiseleva, S.; Stebeneva, V.

2015-11-01

The issue of improving the energy and resource efficiency of advanced petroleum processing can be solved by the development of adequate mathematical model based on physical and chemical regularities of process reactions with a high predictive potential in the advanced petroleum refining. In this work, the development of formalized hydrocarbon conversion scheme of catalytic cracking was performed using thermodynamic parameters of reaction defined by the Density Functional Theory. The list of reaction was compiled according to the results of feedstock structural-group composition definition, which was done by the n-d-m-method, the Hazelvuda method, qualitative composition of feedstock defined by gas chromatography-mass spectrometry and individual composition of catalytic cracking gasoline fraction. Formalized hydrocarbon conversion scheme of catalytic cracking will become the basis for the development of the catalytic cracking kinetic model.

Exploitative and Deceptive Resource Acquisition Strategies

Directory of Open Access Journals (Sweden)

Joshua J. Reynolds

2015-07-01

Full Text Available Life history strategy (LHS and life history contingencies (LHCs should theoretically influence the use of exploitative and deceptive resource acquisition strategies. However, little research has been done in this area. The purpose of the present work was to create measures of exploitative strategies and test the predictions of life history theory. Pilot studies developed and validated a behavioral measure of cheating called the Dot Game. The role of individual LHS and LHCs (manipulated via validated story primes on cheating was investigated in Study 1. Studies 2a through 2c were conducted to develop and validate a self-report measure called the Exploitative and Deceptive Resource Acquisition Strategy Scale (EDRASS. Finally, Study 3 investigated life history and EDRASS. Results indicated that while LHS influences exploitative strategies, life history contingences had little effect. Implications of these findings are discussed.

Delayed feedback control of fractional-order chaotic systems

International Nuclear Information System (INIS)

Gjurchinovski, A; Urumov, V; Sandev, T

2010-01-01

We study the possibility to stabilize unstable steady states and unstable periodic orbits in chaotic fractional-order dynamical systems by the time-delayed feedback method. By performing a linear stability analysis, we establish the parameter ranges for successful stabilization of unstable equilibria in the plane parameterized by the feedback gain and the time delay. An insight into the control mechanism is gained by analyzing the characteristic equation of the controlled system, showing that the control scheme fails to control unstable equilibria having an odd number of positive real eigenvalues. We demonstrate that the method can also stabilize unstable periodic orbits for a suitable choice of the feedback gain, providing that the time delay is chosen to coincide with the period of the target orbit. In addition, it is shown numerically that delayed feedback control with a sinusoidally modulated time delay significantly enlarges the stability region of steady states in comparison to the classical time-delayed feedback scheme with a constant delay.

Trajectories and cycles of sexual exploitation and trafficking for sexual exploitation of women in the Peruvian Amazon

OpenAIRE

Mujica, Jaris

2015-01-01

The commercial sexual exploitation is a constant activity in the Peruvian Amazon. Around the river port of Pucallpa in ucayali region, the practice appears systematically: teenage attend taverns around the port, and those dedicated to the work of cooking camps logging, are victims of constant exploitation and many also of trafficking. this article aims to reconstruct the path of life and reproductive cycle of the forms of exploitation in a sample of 20 women, and focuses on: (i) evidence of s...

The decay scheme of 229Ra

International Nuclear Information System (INIS)

Yang, W.F.; Yuan, S.G.; Fang, K.M.; Shen, S.F.; Mou, W.T.; Zhang, X.Q.; Li, Z.Q.

1997-01-01

By bombarding the natural thorium targets with 14 MeV neutrons, 229 Ra was produced through the reaction 232 Th(n,α) 229 Ra. The radium activities were separated from the irradiated targets by coprecipitation with the BaCl 2 . A total of 18 new weak γ rays with energies of 14.5, 15.6, 18.8, 21.8, 22.5, 44.0, 47.5, 55.0, 63.0, 69.6, 93.6, 94.1, 98.5, 102.2, 104.5, 106.1, 161.1, and 171.5 keV which could be assigned to the decay of 229 Ra were observed in the isolated radium fractions employing high resolution HPGe detectors and γ(X)-γ coincidence methods. A decay scheme of 229 Ra based on these observations is proposed. (orig.). With 2 figs

Disturbance observer-based adaptive sliding mode hybrid projective synchronisation of identical fractional-order financial systems

Science.gov (United States)

Khan, Ayub; Tyagi, Arti

2018-05-01

In this paper, we have studied the hybrid projective synchronisation for incommensurate, integer and commensurate fractional-order financial systems with unknown disturbance. To tackle the problem of unknown bounded disturbance, fractional-order disturbance observer is designed to approximate the unknown disturbance. Further, we have introduced simple sliding mode surface and designed adaptive sliding mode controllers incorporating with the designed fractional-order disturbance observer to achieve a bounded hybrid projective synchronisation between two identical fractional-order financial model with different initial conditions. It is shown that the slave system with disturbance can be synchronised with the projection of the master system generated through state transformation. Simulation results are presented to ensure the validity and effectiveness of the proposed sliding mode control scheme in the presence of external bounded unknown disturbance. Also, synchronisation error for commensurate, integer and incommensurate fractional-order financial systems is studied in numerical simulation.

The optimal fraction size in high-dose-rate brachytherapy: dependency on tissue repair kinetics and low-dose rate

International Nuclear Information System (INIS)

Sminia, Peter; Schneider, Christoph J.; Fowler, Jack F.

2002-01-01

Background and Purpose: Indications of the existence of long repair half-times on the order of 2-4 h for late-responding human normal tissues have been obtained from continuous hyperfractionated accelerated radiotherapy (CHART). Recently, these data were used to explain, on the basis of the biologically effective dose (BED), the potential superiority of fractionated high-dose rate (HDR) with large fraction sizes of 5-7 Gy over continuous low-dose rate (LDR) irradiation at 0.5 Gy/h in cervical carcinoma. We investigated the optimal fraction size in HDR brachytherapy and its dependency on treatment choices (overall treatment time, number of HDR fractions, and time interval between fractions) and treatment conditions (reference low-dose rate, tissue repair characteristics). Methods and Materials: Radiobiologic model calculations were performed using the linear-quadratic model for incomplete mono-exponential repair. An irradiation dose of 20 Gy was assumed to be applied either with HDR in 2-12 fractions or continuously with LDR for a range of dose rates. HDR and LDR treatment regimens were compared on the basis of the BED and BED ratio of normal tissue and tumor, assuming repair half-times between 1 h and 4 h. Results: With the assumption that the repair half-time of normal tissue was three times longer than that of the tumor, hypofractionation in HDR relative to LDR could result in relative normal tissue sparing if the optimum fraction size is selected. By dose reduction while keeping the tumor BED constant, absolute normal tissue sparing might therefore be achieved. This optimum HDR fraction size was found to be largely dependent on the LDR dose rate. On the basis of the BED NT/TUM ratio of HDR over LDR, 3 x 6.7 Gy would be the optimal HDR fractionation scheme for replacement of an LDR scheme of 20 Gy in 10-30 h (dose rate 2-0.67 Gy/h), while at a lower dose rate of 0.5 Gy/h, four fractions of 5 Gy would be preferential, still assuming large differences between tumor

Study of Cu and Pb partitioning in mine tailings using the Tessier sequential extraction scheme

Energy Technology Data Exchange (ETDEWEB)

Andrei, Mariana Lucia, E-mail: marianaluciaandrei@yahoo.com [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Babes-Bolyai University, Environmental Science and Engineering Faculty, 30 Fantanele, 400294, Cluj-Napoca (Romania); Senila, Marin; Hoaghia, Maria Alexandra; Levei, Erika-Andrea [INCDO-INOE 2000, Research Institute for Analytical Instrumentation, 67 Donath, 400293, Cluj-Napoca (Romania); Borodi, Gheorghe [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

2015-12-23

The Cu and Pb partitioning in nonferrous mine tailings was investigated using the Tessier sequential extraction scheme. The contents of Cu and Pb found in the five operationally defined fractions were determined by inductively coupled plasma optical emission spectrometry. The results showed different partitioning patterns for Cu and Pb in the studied tailings. The total Cu and Pb contents were higher in tailings from Brazesti than in those from Saliste, while the Cu contents in the first two fractions considered as mobile were comparable and the content of mobile Pb was the highest in Brazesti tailings. In the tailings from Saliste about 30% of Cu and 3% of Pb were found in exchangeable fraction, while in those from Brazesti no metals were found in the exchangeable fraction, but the percent of Cu and Pb found in the bound to carbonate fraction were high (20% and 26%, respectively). The highest Pb content was found in the residual fraction in Saliste tailings and in bound to Fe and Mn oxides fraction in Brazesti tailings, while the highest Cu content was found in the fraction bound to organic matter in Saliste tailings and in the residual fraction in Brazesti tailings. In case of tailings of Brazesti medium environmental risk was found both for Pb and Cu, while in case of Saliste tailings low risk for Pb and high risk for Cu were found.

Study of Cu and Pb partitioning in mine tailings using the Tessier sequential extraction scheme

International Nuclear Information System (INIS)

Andrei, Mariana Lucia; Senila, Marin; Hoaghia, Maria Alexandra; Levei, Erika-Andrea; Borodi, Gheorghe

2015-01-01

The Cu and Pb partitioning in nonferrous mine tailings was investigated using the Tessier sequential extraction scheme. The contents of Cu and Pb found in the five operationally defined fractions were determined by inductively coupled plasma optical emission spectrometry. The results showed different partitioning patterns for Cu and Pb in the studied tailings. The total Cu and Pb contents were higher in tailings from Brazesti than in those from Saliste, while the Cu contents in the first two fractions considered as mobile were comparable and the content of mobile Pb was the highest in Brazesti tailings. In the tailings from Saliste about 30% of Cu and 3% of Pb were found in exchangeable fraction, while in those from Brazesti no metals were found in the exchangeable fraction, but the percent of Cu and Pb found in the bound to carbonate fraction were high (20% and 26%, respectively). The highest Pb content was found in the residual fraction in Saliste tailings and in bound to Fe and Mn oxides fraction in Brazesti tailings, while the highest Cu content was found in the fraction bound to organic matter in Saliste tailings and in the residual fraction in Brazesti tailings. In case of tailings of Brazesti medium environmental risk was found both for Pb and Cu, while in case of Saliste tailings low risk for Pb and high risk for Cu were found

Further test of new pairing scheme used in overhaul of BCS theory

International Nuclear Information System (INIS)

Zheng, X.H.; Walmsley, D.G.

2014-01-01

Highlights: • Explanation of a new pairing scheme to overhaul BCS theory. • Prediction of superconductor properties from normal state resistivity. • Applications to Nb, Pb, Al, Ta, Mo, Ir and W, T c between 9.5 and 0.012 K. • High accuracy compared with measured energy gap of Nb, Pb, Al and Ta. • Prediction of energy gap for Mo, Ir and W (so far not measured). - Abstract: A new electron pairing scheme, rectifying a fundamental flaw of the BCS theory, is tested extensively. It postulates that superconductivity arises solely from residual umklapp scattering when it is not in competition for the same destination electron states with normal scattering. It reconciles a long standing theoretical discrepancy in the strength of the electron–phonon interaction between the normal and superconductive states. The new scheme is exploited to calculate the superconductive electron–phonon spectral density, α 2 F(ν), entirely on the basis of normal state electrical resistivity. This leads to first principles superconductive properties (zero temperature energy gap and tunnelling conductance) in seven metals which turn out to be highly accurate when compared with known data; in other cases experimental verification is invited. The transition temperatures involved vary over almost three orders of magnitude: from 9.5 K for niobium to 0.012 K for tungsten

Finite Boltzmann schemes

NARCIS (Netherlands)

Sman, van der R.G.M.

2006-01-01

In the special case of relaxation parameter = 1 lattice Boltzmann schemes for (convection) diffusion and fluid flow are equivalent to finite difference/volume (FD) schemes, and are thus coined finite Boltzmann (FB) schemes. We show that the equivalence is inherent to the homology of the

A meshless method for solving two-dimensional variable-order time fractional advection-diffusion equation

Science.gov (United States)

Tayebi, A.; Shekari, Y.; Heydari, M. H.

2017-07-01

Several physical phenomena such as transformation of pollutants, energy, particles and many others can be described by the well-known convection-diffusion equation which is a combination of the diffusion and advection equations. In this paper, this equation is generalized with the concept of variable-order fractional derivatives. The generalized equation is called variable-order time fractional advection-diffusion equation (V-OTFA-DE). An accurate and robust meshless method based on the moving least squares (MLS) approximation and the finite difference scheme is proposed for its numerical solution on two-dimensional (2-D) arbitrary domains. In the time domain, the finite difference technique with a θ-weighted scheme and in the space domain, the MLS approximation are employed to obtain appropriate semi-discrete solutions. Since the newly developed method is a meshless approach, it does not require any background mesh structure to obtain semi-discrete solutions of the problem under consideration, and the numerical solutions are constructed entirely based on a set of scattered nodes. The proposed method is validated in solving three different examples including two benchmark problems and an applied problem of pollutant distribution in the atmosphere. In all such cases, the obtained results show that the proposed method is very accurate and robust. Moreover, a remarkable property so-called positive scheme for the proposed method is observed in solving concentration transport phenomena.

On the conductance sum rule for the hierarchical edge states of the fractional quantum hall effect

International Nuclear Information System (INIS)

Ma Zhongshui; Chen Yixin; Su Zhaobin.

1993-09-01

The conductance sum rule for the hierarchical edge channel currents of a Fractional Quantum Hall Effect state is derived analytically within the Haldane-Halperin hierarchy scheme. We provide also an intuitive interpretation for the hierarchical drift velocities of the edge excitations. (author). 12 refs

Adaptative synchronization in multi-output fractional-order complex dynamical networks and secure communications

Science.gov (United States)

Mata-Machuca, Juan L.; Aguilar-López, Ricardo

2018-01-01

This work deals with the adaptative synchronization of complex dynamical networks with fractional-order nodes and its application in secure communications employing chaotic parameter modulation. The complex network is composed of multiple fractional-order systems with mismatch parameters and the coupling functions are given to realize the network synchronization. We introduce a fractional algebraic synchronizability condition (FASC) and a fractional algebraic identifiability condition (FAIC) which are used to know if the synchronization and parameters estimation problems can be solved. To overcome these problems, an adaptative synchronization methodology is designed; the strategy consists in proposing multiple receiver systems which tend to follow asymptotically the uncertain transmitters systems. The coupling functions and parameters of the receiver systems are adjusted continually according to a convenient sigmoid-like adaptative controller (SLAC), until the measurable output errors converge to zero, hence, synchronization between transmitter and receivers is achieved and message signals are recovered. Indeed, the stability analysis of the synchronization error is based on the fractional Lyapunov direct method. Finally, numerical results corroborate the satisfactory performance of the proposed scheme by means of the synchronization of a complex network consisting of several fractional-order unified chaotic systems.

A Reconfiguration Scheme for Accommodating Actuator Failures in Multi-Input, Multi-Output Flight Control Systems

Science.gov (United States)

Siwakosit, W.; Hess, R. A.; Bacon, Bart (Technical Monitor); Burken, John (Technical Monitor)

2000-01-01

A multi-input, multi-output reconfigurable flight control system design utilizing a robust controller and an adaptive filter is presented. The robust control design consists of a reduced-order, linear dynamic inversion controller with an outer-loop compensation matrix derived from Quantitative Feedback Theory (QFT). A principle feature of the scheme is placement of the adaptive filter in series with the QFT compensator thus exploiting the inherent robustness of the nominal flight control system in the presence of plant uncertainties. An example of the scheme is presented in a pilot-in-the-loop computer simulation using a simplified model of the lateral-directional dynamics of the NASA F18 High Angle of Attack Research Vehicle (HARV) that included nonlinear anti-wind up logic and actuator limitations. Prediction of handling qualities and pilot-induced oscillation tendencies in the presence of these nonlinearities is included in the example.

Exploitation in International Paid Surrogacy Arrangements.

Science.gov (United States)

Wilkinson, Stephen

2016-05-01

Many critics have suggested that international paid surrogacy is exploitative. Taking such concerns as its starting point, this article asks: (1) how defensible is the claim that international paid surrogacy is exploitative and what could be done to make it less exploitative? (2) In the light of the answer to (1), how strong is the case for prohibiting it? Exploitation could in principle be dealt with by improving surrogates' pay and conditions. However, doing so may exacerbate problems with consent. Foremost amongst these is the argument that surrogates from economically disadvantaged countries cannot validly consent because their background circumstances are coercive. Several versions of this argument are examined and I conclude that at least one has some merit. The article's overall conclusion is that while ethically there is something to be concerned about, paid surrogacy is in no worse a position than many other exploitative commercial transactions which take place against a backdrop of global inequality and constrained options, such as poorly-paid and dangerous construction work. Hence, there is little reason to single surrogacy out for special condemnation. On a policy level, the case for prohibiting international commercial surrogacy is weak, despite legitimate concerns about consent and background poverty.

Exploitation in International Paid Surrogacy Arrangements

Science.gov (United States)

Wilkinson, Stephen

2015-01-01

Abstract Many critics have suggested that international paid surrogacy is exploitative. Taking such concerns as its starting point, this article asks: (1) how defensible is the claim that international paid surrogacy is exploitative and what could be done to make it less exploitative? (2) In the light of the answer to (1), how strong is the case for prohibiting it? Exploitation could in principle be dealt with by improving surrogates' pay and conditions. However, doing so may exacerbate problems with consent. Foremost amongst these is the argument that surrogates from economically disadvantaged countries cannot validly consent because their background circumstances are coercive. Several versions of this argument are examined and I conclude that at least one has some merit. The article's overall conclusion is that while ethically there is something to be concerned about, paid surrogacy is in no worse a position than many other exploitative commercial transactions which take place against a backdrop of global inequality and constrained options, such as poorly‐paid and dangerous construction work. Hence, there is little reason to single surrogacy out for special condemnation. On a policy level, the case for prohibiting international commercial surrogacy is weak, despite legitimate concerns about consent and background poverty. PMID:27471338

A Variable Order Fractional Differential-Based Texture Enhancement Algorithm with Application in Medical Imaging.

Directory of Open Access Journals (Sweden)

Qiang Yu

Full Text Available Texture enhancement is one of the most important techniques in digital image processing and plays an essential role in medical imaging since textures discriminate information. Most image texture enhancement techniques use classical integral order differential mask operators or fractional differential mask operators using fixed fractional order. These masks can produce excessive enhancement of low spatial frequency content, insufficient enhancement of large spatial frequency content, and retention of high spatial frequency noise. To improve upon existing approaches of texture enhancement, we derive an improved Variable Order Fractional Centered Difference (VOFCD scheme which dynamically adjusts the fractional differential order instead of fixing it. The new VOFCD technique is based on the second order Riesz fractional differential operator using a Lagrange 3-point interpolation formula, for both grey scale and colour image enhancement. We then use this method to enhance photographs and a set of medical images related to patients with stroke and Parkinson's disease. The experiments show that our improved fractional differential mask has a higher signal to noise ratio value than the other fractional differential mask operators. Based on the corresponding quantitative analysis we conclude that the new method offers a superior texture enhancement over existing methods.

Drinking Water Quality Criterion - Based site Selection of Aquifer Storage and Recovery Scheme in Chou-Shui River Alluvial Fan

Science.gov (United States)

Huang, H. E.; Liang, C. P.; Jang, C. S.; Chen, J. S.

2015-12-01

Land subsidence due to groundwater exploitation is an urgent environmental problem in Choushui river alluvial fan in Taiwan. Aquifer storage and recovery (ASR), where excess surface water is injected into subsurface aquifers for later recovery, is one promising strategy for managing surplus water and may overcome water shortages. The performance of an ASR scheme is generally evaluated in terms of recovery efficiency, which is defined as percentage of water injected in to a system in an ASR site that fulfills the targeted water quality criterion. Site selection of an ASR scheme typically faces great challenges, due to the spatial variability of groundwater quality and hydrogeological condition. This study proposes a novel method for the ASR site selection based on drinking quality criterion. Simplified groundwater flow and contaminant transport model spatial distributions of the recovery efficiency with the help of the groundwater quality, hydrological condition, ASR operation. The results of this study may provide government administrator for establishing reliable ASR scheme.

Fractionation characterization and speciation of heavy metals in composts and compost and compost-amended soils

International Nuclear Information System (INIS)

Lwegbue, C. M.A.; Emuh, F.N.; Isirimah, N.O.; Egun, A.C.

2007-01-01

Speciation of heavy metals in soils determines the availability for metals for plant uptake and potential for contamination of groundwater following application of composts to agricultural lands. Methods used to characterize heavy metals in solid phase of composts and compost amended soils include physical fractionation and chemical extraction. Chemical extraction schemes are most frequently used approach to fractionate trace metals in soils, sewage sludge and composts. Several variations exist in the sequential extraction procedures. These variations include reagent types, strength, volume and extraction time. A main drawback shared by all sequential extraction schemes is that the procedures themselves are complex and time consuming. This setback has been overcome by the use of ultrasound accelerated extraction which reduce the extraction time for the entire extraction steps to about 90 minutes allowing composting process to be monitored more frequently which help to provide detailed understanding of the partitioning behaviour of heavy metals. Inspite of the variability the sequential extraction schemes, they all aimed at correlating each fraction with the mobility and plant availability of each metal. Several studies have shown that phase association of heavy metal in composts include water-soluble, exchangeable, precipitated as discrete phases, co-precipitate in metal oxides and adsorbed or complexed by organic ligands and residual forms. The phase association and solubility of metals changes over composting time thereby altering metal availability. It is apparent that the positive effects of resulting from compost application far outweigh the negative effect, but more research is needed on a wide range of municipal solid waste compost with more precise determination of the fate of municipal solid waste compost applied trace metals in the environment. (author)

Exploitation and exploration dynamics in recessionary times

OpenAIRE

Walrave, B.

2012-01-01

Firm performance largely depends on the ability to adapt to, and exploit, changes in the business environment. That is, firms should maintain ecological fitness by reconfiguring their resource base to cope with emerging threats and explore new opportunities, while at the same time exploiting existing resources. As such, firms possessing the ability to simultaneously perform exploitative and explorative initiatives are more resilient. In this respect, the performance implications of balancing ...

Fractionation and Mobility of Thallium in Volcanic Ashes after Eruption of Eyjafjallajökull (2010) in Iceland.

Science.gov (United States)

Karbowska, Bozena; Zembrzuski, Wlodzimierz

2016-07-01

Volcanic ash contains thallium (Tl), which is highly toxic to the biosphere. The aim of this study was to determine the Tl concentration in fractions of volcanic ash samples originating from the Eyjafjallajökull volcano. A sequential extraction scheme allowed for a study of element migration in the environment. Differential pulse anodic stripping voltammetry using a flow measuring system was selected as the analytical method to determine Tl content. The highest average content of Tl in volcanic ash was determined in the fraction entrapped in the aluminosilicate matrix (0.329 µg g(-1)), followed by the oxidizable fraction (0.173 µg g(-1)). The lowest content of Tl was found in the water soluble fraction (0.001 µg g(-1)); however, this fraction is important due to the fact that Tl redistribution among all the fractions occurs through the aqueous phase.

Prostate IMRT fractionation strategies. Two-phase treatment versus simultaneous integrated boost

International Nuclear Information System (INIS)

Stavrev, P.; Hristov, D.

2003-01-01

Background. The purpose of the study was to investigate the radiobiological effect of the number of fractions, position uncertainties and clonogen spread (microscopic disease) on two different inverse treatment planning alternatives: (a) 2-phase strategy; (b) simultaneous integrated boost (SIB). Material and methods. The tumour control probability (TCP) and normal tissue complication probability (NTCP) were calculated for the 2-phase strategy, which has well defined fractionation scheme and compared to the TCP and NTCP for the SIB strategy calculated as a function of the number of fractions. For a 7-beam IMRT prostate treatment, we have performed inverse treatment planning for the two different strategies following the above method. Results. When the position uncertainties and clonogen spread were accounted for in the TCP calculation a drop as large as 10% was found. A drop of 5-7% in the TCP was obtained for the SIB strategy, if delivered in the same number of fractions as the 2-phased one. Conclusions. The potential of inverse planning to design tight conformal dose distributions is fully revealed in the SIB optimization process. The optimized SIB superior dose distributions require modification of the delivered dose per fraction and therefore careful selection of the fractionation regime. Hence physically optimized SIB treatments may not always lead to better tumour control and tissue sparing. (author)

Poverty-Exploitation-Alienation.

Science.gov (United States)

Bronfenbrenner, Martin

1980-01-01

Illustrates how knowledge derived from the discipline of economics can be used to help shed light on social problems such as poverty, exploitation, and alienation, and can help decision makers form policy to minimize these and similar problems. (DB)

Microwave Determination of Water Mole Fraction in Humid Gas Mixtures

Science.gov (United States)

Cuccaro, R.; Gavioso, R. M.; Benedetto, G.; Madonna Ripa, D.; Fernicola, V.; Guianvarc'h, C.

2012-09-01

A small volume (65 cm3) gold-plated quasi-spherical microwave resonator has been used to measure the water vapor mole fraction x w of H2O/N2 and H2O/air mixtures. This experimental technique exploits the high precision achievable in the determination of the cavity microwave resonance frequencies and is particularly sensitive to the presence of small concentrations of water vapor as a result of the high polarizability of this substance. The mixtures were prepared using the INRIM standard humidity generator for frost-point temperatures T fp in the range between 241 K and 270 K and a commercial two-pressure humidity generator operated at a dew-point temperature between 272 K and 291 K. The experimental measurements compare favorably with the calculated molar fractions of the mixture supplied by the humidity generators, showing a normalized error lower than 0.8.

An Adaptive Data Gathering Scheme for Multi-Hop Wireless Sensor Networks Based on Compressed Sensing and Network Coding.

Science.gov (United States)

Yin, Jun; Yang, Yuwang; Wang, Lei

2016-04-01

Joint design of compressed sensing (CS) and network coding (NC) has been demonstrated to provide a new data gathering paradigm for multi-hop wireless sensor networks (WSNs). By exploiting the correlation of the network sensed data, a variety of data gathering schemes based on NC and CS (Compressed Data Gathering--CDG) have been proposed. However, these schemes assume that the sparsity of the network sensed data is constant and the value of the sparsity is known before starting each data gathering epoch, thus they ignore the variation of the data observed by the WSNs which are deployed in practical circumstances. In this paper, we present a complete design of the feedback CDG scheme where the sink node adaptively queries those interested nodes to acquire an appropriate number of measurements. The adaptive measurement-formation procedure and its termination rules are proposed and analyzed in detail. Moreover, in order to minimize the number of overall transmissions in the formation procedure of each measurement, we have developed a NP-complete model (Maximum Leaf Nodes Minimum Steiner Nodes--MLMS) and realized a scalable greedy algorithm to solve the problem. Experimental results show that the proposed measurement-formation method outperforms previous schemes, and experiments on both datasets from ocean temperature and practical network deployment also prove the effectiveness of our proposed feedback CDG scheme.

Error analysis of semidiscrete finite element methods for inhomogeneous time-fractional diffusion

KAUST Repository

Jin, B.; Lazarov, R.; Pasciak, J.; Zhou, Z.

2014-01-01

© 2014 Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved. We consider the initial-boundary value problem for an inhomogeneous time-fractional diffusion equation with a homogeneous Dirichlet boundary condition, a vanishing initial data and a nonsmooth right-hand side in a bounded convex polyhedral domain. We analyse two semidiscrete schemes based on the standard Galerkin and lumped mass finite element methods. Almost optimal error estimates are obtained for right-hand side data f (x, t) ε L∞ (0, T; Hq(ω)), ≤1≥ 1, for both semidiscrete schemes. For the lumped mass method, the optimal L2(ω)-norm error estimate requires symmetric meshes. Finally, twodimensional numerical experiments are presented to verify our theoretical results.

Error analysis of semidiscrete finite element methods for inhomogeneous time-fractional diffusion

KAUST Repository

Jin, B.

2014-05-30

© 2014 Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved. We consider the initial-boundary value problem for an inhomogeneous time-fractional diffusion equation with a homogeneous Dirichlet boundary condition, a vanishing initial data and a nonsmooth right-hand side in a bounded convex polyhedral domain. We analyse two semidiscrete schemes based on the standard Galerkin and lumped mass finite element methods. Almost optimal error estimates are obtained for right-hand side data f (x, t) ε L∞ (0, T; Hq(ω)), ≤1≥ 1, for both semidiscrete schemes. For the lumped mass method, the optimal L2(ω)-norm error estimate requires symmetric meshes. Finally, twodimensional numerical experiments are presented to verify our theoretical results.

Total variation regularization for a backward time-fractional diffusion problem

International Nuclear Information System (INIS)

Wang, Liyan; Liu, Jijun

2013-01-01

Consider a two-dimensional backward problem for a time-fractional diffusion process, which can be considered as image de-blurring where the blurring process is assumed to be slow diffusion. In order to avoid the over-smoothing effect for object image with edges and to construct a fast reconstruction scheme, the total variation regularizing term and the data residual error in the frequency domain are coupled to construct the cost functional. The well posedness of this optimization problem is studied. The minimizer is sought approximately using the iteration process for a series of optimization problems with Bregman distance as a penalty term. This iteration reconstruction scheme is essentially a new regularizing scheme with coupling parameter in the cost functional and the iteration stopping times as two regularizing parameters. We give the choice strategy for the regularizing parameters in terms of the noise level of measurement data, which yields the optimal error estimate on the iterative solution. The series optimization problems are solved by alternative iteration with explicit exact solution and therefore the amount of computation is much weakened. Numerical implementations are given to support our theoretical analysis on the convergence rate and to show the significant reconstruction improvements. (paper)

Dose fractionated gamma knife radiosurgery for large arteriovenous malformations on daily or alternate day schedule outside the linear quadratic model: Proof of concept and early results. A substitute to volume fractionation.

Science.gov (United States)

Mukherjee, Kanchan Kumar; Kumar, Narendra; Tripathi, Manjul; Oinam, Arun S; Ahuja, Chirag K; Dhandapani, Sivashanmugam; Kapoor, Rakesh; Ghoshal, Sushmita; Kaur, Rupinder; Bhatt, Sandeep

2017-01-01

To evaluate the feasibility, safety and efficacy of dose fractionated gamma knife radiosurgery (DFGKRS) on a daily schedule beyond the linear quadratic (LQ) model, for large volume arteriovenous malformations (AVMs). Between 2012-16, 14 patients of large AVMs (median volume 26.5 cc) unsuitable for surgery or embolization were treated in 2-3 of DFGKRS sessions. The Leksell G frame was kept in situ during the whole procedure. 86% (n = 12) patients had radiologic evidence of bleed, and 43% (n = 6) had presented with a history of seizures. 57% (n = 8) patients received a daily treatment for 3 days and 43% (n = 6) were on an alternate day (2 fractions) regimen. The marginal dose was split into 2 or 3 fractions of the ideal prescription dose of a single fraction of 23-25 Gy. The median follow up period was 35.6 months (8-57 months). In the three-fraction scheme, the marginal dose ranged from 8.9-11.5 Gy, while in the two-fraction scheme, the marginal dose ranged from 11.3-15 Gy at 50% per fraction. Headache (43%, n = 6) was the most common early postoperative complication, which was controlled with short course steroids. Follow up evaluation of at least three years was achieved in seven patients, who have shown complete nidus obliteration in 43% patients while the obliteration has been in the range of 50-99% in rest of the patients. Overall, there was a 67.8% reduction in the AVM volume at 3 years. Nidus obliteration at 3 years showed a significant rank order correlation with the cumulative prescription dose (p 0.95, P value 0.01), with attainment of near-total (more than 95%) obliteration rates beyond 29 Gy of the cumulative prescription dose. No patient receiving a cumulative prescription dose of less than 31 Gy had any severe adverse reaction. In co-variate adjusted ordinal regression, only the cumulative prescription dose had a significant correlation with common terminology criteria for adverse events (CTCAE) severity (P value 0.04), independent of age, AVM volume

A novel scheme for making cheap electricity with nuclear energy

International Nuclear Information System (INIS)

Pettibone, J.S.

1991-04-01

Nuclear fuels should produce cheaper electricity than coal, considering their high specific energy and low cost. To exploit these properties, the scheme proposed here replaces the expensive reactor/steam-turbine system with an engine in which the expansion of a gas heated by a nuclear explosion raises a mass of liquid, thereby producing stored hydraulic energy. This energy could be converted to electricity by hydroelectric generation with water as the working fluid or by magnetohydrodynamic (MHD) generation with molten metal. A rough cost analysis suggests the hydroelectric system could reduce the present cost of electricity by two-thirds, and the MHD system by even more. Such cheap power would make feasible large-scale electrolysis to produce hydrogen and other fuels and chemical raw materials. 2 refs., 1 fig

An efficient communication scheme for solving Sn equations on message-passing multiprocessors

International Nuclear Information System (INIS)

Azmy, Y.Y.

1993-01-01

Early models of Intel's hypercube multiprocessors, e.g., the iPSC/1 and iPSC/2, were characterized by the high latency of message passing. This relatively weak dependence of the communication penalty on the size of messages, in contrast to its strong dependence on the number of messages, justified using the Fan-in Fan-out algorithm (which implements a minimum spanning tree path) to perform global operations, such as global sums, etc. Recent models of message-passing computers, such as the iPSC/860 and the Paragon, have been found to possess much smaller latency, thus forcing a reexamination of the issue of performance optimization with respect to communication schemes. Essentially, the Fan-in Fan-out scheme minimizes the number of nonsimultaneous messages sent but not the volume of data traffic across the network. Furthermore, if a global operation is performed in conjunction with the message passing, a large fraction of the attached nodes remains idle as the number of utilized processors is halved in each step of the process. On the other hand, the Recursive Halving scheme offers the smallest communication cost for global operations but has some drawbacks

Accurate B-spline-based 3-D interpolation scheme for digital volume correlation

Science.gov (United States)

Ren, Maodong; Liang, Jin; Wei, Bin

2016-12-01

An accurate and efficient 3-D interpolation scheme, based on sampling theorem and Fourier transform technique, is proposed to reduce the sub-voxel matching error caused by intensity interpolation bias in digital volume correlation. First, the influence factors of the interpolation bias are investigated theoretically using the transfer function of an interpolation filter (henceforth filter) in the Fourier domain. A law that the positional error of a filter can be expressed as a function of fractional position and wave number is found. Then, considering the above factors, an optimized B-spline-based recursive filter, combining B-spline transforms and least squares optimization method, is designed to virtually eliminate the interpolation bias in the process of sub-voxel matching. Besides, given each volumetric image containing different wave number ranges, a Gaussian weighting function is constructed to emphasize or suppress certain of wave number ranges based on the Fourier spectrum analysis. Finally, a novel software is developed and series of validation experiments were carried out to verify the proposed scheme. Experimental results show that the proposed scheme can reduce the interpolation bias to an acceptable level.

Radiation environmental impact assessment of copper exploitation

International Nuclear Information System (INIS)

Fan Guang; Wen Zhijian

2010-01-01

The radiation environmental impact of mineral exploitation on the surrounding environment has become a public concern. This paper presents the radiation environmental impact assessment of copper exploitation. Based on the project description and detailed investigations of surrounding environment, systematic radiation environmental impacts have been identified. The environmental impacts are assessed during both construction and operation phase. The environmental protection measures have also been proposed. The related conclusion and measures can play an active role in copper exploitation and environmental protection. (authors)

LPTA: location predictive and time adaptive data gathering scheme with mobile sink for wireless sensor networks.

Science.gov (United States)

Zhu, Chuan; Wang, Yao; Han, Guangjie; Rodrigues, Joel J P C; Lloret, Jaime

2014-01-01

This paper exploits sink mobility to prolong the lifetime of sensor networks while maintaining the data transmission delay relatively low. A location predictive and time adaptive data gathering scheme is proposed. In this paper, we introduce a sink location prediction principle based on loose time synchronization and deduce the time-location formulas of the mobile sink. According to local clocks and the time-location formulas of the mobile sink, nodes in the network are able to calculate the current location of the mobile sink accurately and route data packets timely toward the mobile sink by multihop relay. Considering that data packets generating from different areas may be different greatly, an adaptive dwelling time adjustment method is also proposed to balance energy consumption among nodes in the network. Simulation results show that our data gathering scheme enables data routing with less data transmission time delay and balance energy consumption among nodes.

Lifting scheme-based method for joint coding 3D stereo digital cinema with luminace correction and optimized prediction

Science.gov (United States)

Darazi, R.; Gouze, A.; Macq, B.

2009-01-01

Reproducing a natural and real scene as we see in the real world everyday is becoming more and more popular. Stereoscopic and multi-view techniques are used for this end. However due to the fact that more information are displayed requires supporting technologies such as digital compression to ensure the storage and transmission of the sequences. In this paper, a new scheme for stereo image coding is proposed. The original left and right images are jointly coded. The main idea is to optimally exploit the existing correlation between the two images. This is done by the design of an efficient transform that reduces the existing redundancy in the stereo image pair. This approach was inspired by Lifting Scheme (LS). The novelty in our work is that the prediction step is been replaced by an hybrid step that consists in disparity compensation followed by luminance correction and an optimized prediction step. The proposed scheme can be used for lossless and for lossy coding. Experimental results show improvement in terms of performance and complexity compared to recently proposed methods.

Adaptive protection scheme

Directory of Open Access Journals (Sweden)

R. Sitharthan

2016-09-01

Full Text Available This paper aims at modelling an electronically coupled distributed energy resource with an adaptive protection scheme. The electronically coupled distributed energy resource is a microgrid framework formed by coupling the renewable energy source electronically. Further, the proposed adaptive protection scheme provides a suitable protection to the microgrid for various fault conditions irrespective of the operating mode of the microgrid: namely, grid connected mode and islanded mode. The outstanding aspect of the developed adaptive protection scheme is that it monitors the microgrid and instantly updates relay fault current according to the variations that occur in the system. The proposed adaptive protection scheme also employs auto reclosures, through which the proposed adaptive protection scheme recovers faster from the fault and thereby increases the consistency of the microgrid. The effectiveness of the proposed adaptive protection is studied through the time domain simulations carried out in the PSCAD⧹EMTDC software environment.

Fractional dynamics of charged particles in magnetic fields

Science.gov (United States)

Coronel-Escamilla, A.; Gómez-Aguilar, J. F.; Alvarado-Méndez, E.; Guerrero-Ramírez, G. V.; Escobar-Jiménez, R. F.

2016-02-01

In many physical applications the electrons play a relevant role. For example, when a beam of electrons accelerated to relativistic velocities is used as an active medium to generate Free Electron Lasers (FEL), the electrons are bound to atoms, but move freely in a magnetic field. The relaxation time, longitudinal effects and transverse variations of the optical field are parameters that play an important role in the efficiency of this laser. The electron dynamics in a magnetic field is a means of radiation source for coupling to the electric field. The transverse motion of the electrons leads to either gain or loss energy from or to the field, depending on the position of the particle regarding the phase of the external radiation field. Due to the importance to know with great certainty the displacement of charged particles in a magnetic field, in this work we study the fractional dynamics of charged particles in magnetic fields. Newton’s second law is considered and the order of the fractional differential equation is (0;1]. Based on the Grünwald-Letnikov (GL) definition, the discretization of fractional differential equations is reported to get numerical simulations. Comparison between the numerical solutions obtained on Euler’s numerical method for the classical case and the GL definition in the fractional approach proves the good performance of the numerical scheme applied. Three application examples are shown: constant magnetic field, ramp magnetic field and harmonic magnetic field. In the first example the results obtained show bistability. Dissipative effects are observed in the system and the standard dynamic is recovered when the order of the fractional derivative is 1.

Comparative study of numerical schemes of TVD3, UNO3-ACM and optimized compact scheme

Science.gov (United States)

Lee, Duck-Joo; Hwang, Chang-Jeon; Ko, Duck-Kon; Kim, Jae-Wook

1995-01-01

Three different schemes are employed to solve the benchmark problem. The first one is a conventional TVD-MUSCL (Monotone Upwind Schemes for Conservation Laws) scheme. The second scheme is a UNO3-ACM (Uniformly Non-Oscillatory Artificial Compression Method) scheme. The third scheme is an optimized compact finite difference scheme modified by us: the 4th order Runge Kutta time stepping, the 4th order pentadiagonal compact spatial discretization with the maximum resolution characteristics. The problems of category 1 are solved by using the second (UNO3-ACM) and third (Optimized Compact) schemes. The problems of category 2 are solved by using the first (TVD3) and second (UNO3-ACM) schemes. The problem of category 5 is solved by using the first (TVD3) scheme. It can be concluded from the present calculations that the Optimized Compact scheme and the UN03-ACM show good resolutions for category 1 and category 2 respectively.

GC-MS profile of antimicrobial and antioxidant fractions from Cordia rothii roots.

Science.gov (United States)

Khan, Kehkashan; Firdous, Sadiqa; Ahmad, Aqeel; Fayyaz, Nida; Nadir, Muhammad; Rasheed, Munawwer; Faizi, Shaheen

2016-11-01

An ethnobotanical survey of Cordia rothii Roem. & Schult. (Boraginaceae) reveals it as a medicinal plant. Antimicrobial and antioxidant potential evaluation and identification of chemical constituents via GC-MS of C. rothii roots fractions. To the best of our knowledge, this is the first systematic investigation of the roots exploiting GC-MS. Extraction and fractionation of C. rothii roots furnished various fractions using solvents of varying polarity, i.e., n-hexane, chloroform, ethyl acetate, acetone and methanol. In vitro antimicrobial and antioxidant screening was performed using disk diffusion and DPPH methods, respectively. MIC of active fractions was also determined using disk diffusion method. GC-MS was used to identify constituents which may be responsible for these activities. Among various fractions from C. rothii roots, fraction KA-C showed strong antibacterial activity against 17 microorganisms tested, with MIC ranging from 250-31.25 μg/mL. Fractions KA-A, KM and KM-A exhibited significant antioxidant potential with EC 50 46.875 μg/mL, while fractions KEA-PE, KM-PE and KM-M were good with EC 50 93.750 μg/mL. Forty-five phytochemicals were identified in GC-MS studies including eight hydrocarbons, six free fatty acids, 11 fatty acids esters, two phenylpropanoids, four aromatics, four terpenoid quinones/hydroquinones, three triterpenes, four phytosterols, two hexose metabolites and a DNA base. Of these, 32 constituents have been reported for the first time from C. rothii, 24 from genus Cordia and 15 from Boraginaceae. Strong antibacterial and antioxidant potential of C. rothii roots may be due to the contribution of phytoconstituents identified through GC-MS studies.

A combination anaerobic digestion scheme for biogas production from dairy effluent-CSTR and ABR, and biogas upgrading

DEFF Research Database (Denmark)

Jürgensen, Lars; Ehimen, Ehiaze Augustine; Born, Jens

2018-01-01

Anaerobic digestion of low-strength dairy waste water was used for the production of biogas which is aimed at serving as a concentrated carbon dioxide (CO2) source for further methanation. Using hydrogen (which can be produced via electrolysis using renewably sourced electricity), the CO2 fraction...... of the produced biogas can be used as a mechanism to store surplus electricity by the Sabatier process, which converts the CO2 fractions to methane (CH4), i. e. synthetic natural gas. This study investigates the use a combined reactor scheme for the anaerobic digestion of dairy waste water, and the further...

Cosimulation of electromagnetics-circuit systems exploiting DGTD and MNA

KAUST Repository

Li, Ping

2014-06-01

A hybrid electromagnetics (EM)-circuit simulator exploiting the discontinuous Galerkin time domain (DGTD) method and the modified nodal analysis (MNA) algorithm is developed for analyzing hybrid distributive and nonlinear multiport lumped circuit systems. The computational domain is split into two subsystems. One is the EM subsystem that is analyzed by DGTD, while the other is the circuit subsystem that is solved by the MNA method. The coupling between the EM and circuit subsystems is enforced at the lumped port where related field and circuit unknowns are coupled via the use of numerical flux, port voltages, and current sources. Since the spatial operations of DGTD are localized, thanks to the use of numerical flux, coupling matrices between EM and circuit subsystems are small and are directly inverted. To handle nonlinear devices within the circuit subsystem, the standard Newton-Raphson method is applied to the nonlinear coupling matrix system. In addition, a local time-stepping scheme is applied to improve the efficiency of the hybrid solver. Numerical examples including single and multiport linear/nonlinear circuit networks are presented to validate the proposed solver. © 2014 IEEE.

Competing Discourses about Youth Sexual Exploitation in Canadian News Media.

Science.gov (United States)

Saewyc, Elizabeth M; Miller, Bonnie B; Rivers, Robert; Matthews, Jennifer; Hilario, Carla; Hirakata, Pam

2013-10-01

Media holds the power to create, maintain, or break down stigmatizing attitudes, which affect policies, funding, and services. To understand how Canadian news media depicts the commercial sexual exploitation of children and youth, we examined 835 Canadian newspaper articles from 1989-2008 using a mixed methods critical discourse analysis approach, comparing representations to existing research about sexually exploited youth. Despite research evidence that equal rates of boys and girls experience exploitation, Canadian news media depicted exploited youth predominantly as heterosexual girls, and described them alternately as victims or workers in a trade, often both in the same story. News media mentioned exploiters far less often than victims, and portrayed them almost exclusively as male, most often called 'customers' or 'consumers,' and occasionally 'predators'; in contrast, research has documented the majority of sexually exploited boys report female exploiters. Few news stories over the past two decades portrayed the diversity of victims, perpetrators, and venues of exploitation reported in research. The focus on victims but not exploiters helps perpetuate stereotypes of sexual exploitation as business or a 'victimless crime,' maintains the status quo, and blurs responsibility for protecting youth under the UN Convention on the Rights of the Child. Health care providers and researchers can be advocates for accuracy in media coverage about sexual exploitation; news reporters and editors should focus on exploiters more than victims, draw on existing research evidence to avoid perpetuating stereotypes, and use accurate terms, such as commercial sexual exploitation, rather than terms related to business or trade.

Exploring the applications of fractional calculus: Hierarchically built semiflexible polymers

International Nuclear Information System (INIS)

Fürstenberg, Florian; Dolgushev, Maxim; Blumen, Alexander

2015-01-01

In this article we study, through extensions of the generalized Gaussian scheme, the dynamics of semiflexible treelike polymers under the influence of external forces acting on particular (say, charged) monomers. Semiflexibility is introduced following our previous work (Dolgushev and Blumen, 2009 [15]), a procedure which allows one to study treelike structures with arbitrary stiffness and branching. Exemplarily, we illustrate the procedure using linear chains and hyperbranched polymers modeled through Vicsek fractals, and obtain in every case the monomer displacement averaged over the structure. Anomalous behavior manifests itself in the intermediate time region, where the different fractal architectures show distinct scaling behaviors. These behaviors are due to the power law behavior of the spectral density and lead, for arbitrary pulling forces, based on causality and the linear superposition principle, to fractional calculus expressions, in accordance to former phenomenological fractional laws in polymer physics.

Simulated population responses of common carp to commercial exploitation

Energy Technology Data Exchange (ETDEWEB)

Weber, Michael J.; Hennen, Matthew J.; Brown, Michael L.

2011-12-01

Common carp Cyprinus carpio is a widespread invasive species that can become highly abundant and impose deleterious ecosystem effects. Thus, aquatic resource managers are interested in controlling common carp populations. Control of invasive common carp populations is difficult, due in part to the inherent uncertainty of how populations respond to exploitation. To understand how common carp populations respond to exploitation, we evaluated common carp population dynamics (recruitment, growth, and mortality) in three natural lakes in eastern South Dakota. Common carp exhibited similar population dynamics across these three systems that were characterized by consistent recruitment (ages 3 to 15 years present), fast growth (K = 0.37 to 0.59), and low mortality (A = 1 to 7%). We then modeled the effects of commercial exploitation on size structure, abundance, and egg production to determine its utility as a management tool to control populations. All three populations responded similarly to exploitation simulations with a 575-mm length restriction, representing commercial gear selectivity. Simulated common carp size structure modestly declined (9 to 37%) in all simulations. Abundance of common carp declined dramatically (28 to 56%) at low levels of exploitation (0 to 20%) but exploitation >40% had little additive effect and populations were only reduced by 49 to 79% despite high exploitation (>90%). Maximum lifetime egg production was reduced from 77 to 89% at a moderate level of exploitation (40%), indicating the potential for recruitment overfishing. Exploitation further reduced common carp size structure, abundance, and egg production when simulations were not size selective. Our results provide insights to how common carp populations may respond to exploitation. Although commercial exploitation may be able to partially control populations, an integrated removal approach that removes all sizes of common carp has a greater chance of controlling population abundance

Managing the Innovators for Exploration and Exploitation

Directory of Open Access Journals (Sweden)

C. Annique UN

2007-09-01

Full Text Available I analyze how to manage employees to achieve a balance between exploration and exploitation in large established firms. Previous studies suggest that, although firms need to undertake both exploration and exploitation simultaneously, this is difficult either because of the scarcity of resources or because of the incompatibility of these two processes. Proposed solutions have been ambidexterity, punctuated equilibrium or specialization. I suggest another method: managing employees. Specifically, I argue that using the so-called “innovative” system of human resource management practices, consisting of team-based incentive system, team-based job design, and job rotation, enables the firm to undertake exploration and exploitation simultaneously because it provides the psychological safety for people to explore new knowledge to make novel products and develops employees to have the perspective-taking capability that enables the integration of knowledge cross-functionally for efficiency. Using the so-called “traditional” system of human resource management practices, consisting of individual-based incentive system, individual-based job design, and no job rotation, has limited impact on either exploration or exploitation because it does not create the psychological safety for people to explore new knowledge and does not develop the perspective-taking capability needed for exploitation. Moreover, mixing practices from both systems is better than only using the traditional system in achieving exploration or exploitation, but less effective than only using the innovative system as the mix of practices can create inconsistent expectations on employees.

Fractional Step Like Schemes for Free Surface Problems with Thermal Coupling Using the Lagrangian PFEM

Science.gov (United States)

Aubry, R.; Oñate, E.; Idelsohn, S. R.

2006-09-01

The method presented in Aubry et al. (Comput Struc 83:1459-1475, 2005) for the solution of an incompressible viscous fluid flow with heat transfer using a fully Lagrangian description of motion is extended to three dimensions (3D) with particular emphasis on mass conservation. A modified fractional step (FS) based on the pressure Schur complement (Turek 1999), and related to the class of algebraic splittings Quarteroni et al. (Comput Methods Appl Mech Eng 188:505-526, 2000), is used and a new advantage of the splittings of the equations compared with the classical FS is highlighted for free surface problems. The temperature is semi-coupled with the displacement, which is the main variable in a Lagrangian description. Comparisons for various mesh Reynolds numbers are performed with the classical FS, an algebraic splitting and a monolithic solution, in order to illustrate the behaviour of the Uzawa operator and the mass conservation. As the classical fractional step is equivalent to one iteration of the Uzawa algorithm performed with a standard Laplacian as a preconditioner, it will behave well only in a Reynold mesh number domain where the preconditioner is efficient. Numerical results are provided to assess the superiority of the modified algebraic splitting to the classical FS.

Adaptive Decision-Making Scheme for Cognitive Radio Networks

KAUST Repository

Alqerm, Ismail

2014-05-01

Radio resource management becomes an important aspect of the current wireless networks because of spectrum scarcity and applications heterogeneity. Cognitive radio is a potential candidate for resource management because of its capability to satisfy the growing wireless demand and improve network efficiency. Decision-making is the main function of the radio resources management process as it determines the radio parameters that control the use of these resources. In this paper, we propose an adaptive decision-making scheme (ADMS) for radio resources management of different types of network applications including: power consuming, emergency, multimedia, and spectrum sharing. ADMS exploits genetic algorithm (GA) as an optimization tool for decision-making. It consists of the several objective functions for the decision-making process such as minimizing power consumption, packet error rate (PER), delay, and interference. On the other hand, maximizing throughput and spectral efficiency. Simulation results and test bed evaluation demonstrate ADMS functionality and efficiency.

Transnational gestational surrogacy: does it have to be exploitative?

Science.gov (United States)

Kirby, Jeffrey

2014-01-01

This article explores the controversial practice of transnational gestational surrogacy and poses a provocative question: Does it have to be exploitative? Various existing models of exploitation are considered and a novel exploitation-evaluation heuristic is introduced to assist in the analysis of the potentially exploitative dimensions/elements of complex health-related practices. On the basis of application of the heuristic, I conclude that transnational gestational surrogacy, as currently practiced in low-income country settings (such as rural, western India), is exploitative of surrogate women. Arising out of consideration of the heuristic's exploitation conditions, a set of public education and enabled choice, enhanced protections, and empowerment reforms to transnational gestational surrogacy practice is proposed that, if incorporated into a national regulatory framework and actualized within a low income country, could possibly render such practice nonexploitative.

Exploitation as the Unequal Exchange of Labour : An Axiomatic Approach

OpenAIRE

Yoshihara, Naoki; Veneziani, Roberto

2009-01-01

In subsistence economies with general convex technology and rational optimising agents, a new, axiomatic approach is developed, which allows an explicit analysis of the core positive and normative intuitions behind the concept of exploitation. Three main new axioms, called Labour Exploitation in Subsistence Economies , Relational Exploitation , and Feasibility of Non-Exploitation , are presented and it is proved that they uniquely characterise a definition of exploitation conceptually related...

Finite Time Control for Fractional Order Nonlinear Hydroturbine Governing System via Frequency Distributed Model

Directory of Open Access Journals (Sweden)

Bin Wang

2016-01-01

Full Text Available This paper studies the application of frequency distributed model for finite time control of a fractional order nonlinear hydroturbine governing system (HGS. Firstly, the mathematical model of HGS with external random disturbances is introduced. Secondly, a novel terminal sliding surface is proposed and its stability to origin is proved based on the frequency distributed model and Lyapunov stability theory. Furthermore, based on finite time stability and sliding mode control theory, a robust control law to ensure the occurrence of the sliding motion in a finite time is designed for stabilization of the fractional order HGS. Finally, simulation results show the effectiveness and robustness of the proposed scheme.

Search for fractional charge

International Nuclear Information System (INIS)

Turner, R.E.

1984-01-01

A search was made for fractional charges of the form Z plus two-thirds e, where Z is an integer. It was assumed that the charges exist in natural form bound with other fractional charges in neutral molecules. It was further assumed that these neutral molecules are present in air. Two concentration schemes were employed. One sample was derived from the waste gases from a xenon distillation plant. This assumes that high mass, low vapor pressure components of air are concentrated along with the xenon. The second sample involved ionizing air, allowing a brief recombination period, and then collecting residual ions on the surface of titanium discs. Both samples were analyzed at the University of Rochester in a system using a tandem Van de Graff to accelerate particles through an essentially electrostatic beam handling system. The detector system employed both a Time of Flight and an energy-sensitive gas ionization detector. In the most sensitive mode of analysis, a gas absorber was inserted in the beam path to block the intense background. The presence of an absorber limited the search to highly penetrating particles. Effectively, this limited the search to particles with low Z and masses greater than roughly fifty GeV. The final sensitivities attained were on the order of 1 x 10 -20 for the ionized air sample and 1 x 10 -21 for the gas sample. A discussion of the caveats that could reduce the actual level of sensitivity is included

Analytical modeling for fractional multi-dimensional diffusion equations by using Laplace transform

Directory of Open Access Journals (Sweden)

Devendra Kumar

2015-01-01

Full Text Available In this paper, we propose a simple numerical algorithm for solving multi-dimensional diffusion equations of fractional order which describes density dynamics in a material undergoing diffusion by using homotopy analysis transform method. The fractional derivative is described in the Caputo sense. This homotopy analysis transform method is an innovative adjustment in Laplace transform method and makes the calculation much simpler. The technique is not limited to the small parameter, such as in the classical perturbation method. The scheme gives an analytical solution in the form of a convergent series with easily computable components, requiring no linearization or small perturbation. The numerical solutions obtained by the proposed method indicate that the approach is easy to implement and computationally very attractive.

A Mixed Monotone Operator Method for the Existence and Uniqueness of Positive Solutions to Impulsive Caputo Fractional Differential Equations

Directory of Open Access Journals (Sweden)

Jieming Zhang

2013-01-01

Full Text Available We establish some sufficient conditions for the existence and uniqueness of positive solutions to a class of initial value problem for impulsive fractional differential equations involving the Caputo fractional derivative. Our analysis relies on a fixed point theorem for mixed monotone operators. Our result can not only guarantee the existence of a unique positive solution but also be applied to construct an iterative scheme for approximating it. An example is given to illustrate our main result.

Bounded fractional diffusion in geological media: Definition and Lagrangian approximation

Science.gov (United States)

Zhang, Yong; Green, Christopher T.; LaBolle, Eric M.; Neupauer, Roseanna M.; Sun, HongGuang

2016-01-01

Spatiotemporal Fractional-Derivative Models (FDMs) have been increasingly used to simulate non-Fickian diffusion, but methods have not been available to define boundary conditions for FDMs in bounded domains. This study defines boundary conditions and then develops a Lagrangian solver to approximate bounded, one-dimensional fractional diffusion. Both the zero-value and non-zero-value Dirichlet, Neumann, and mixed Robin boundary conditions are defined, where the sign of Riemann-Liouville fractional derivative (capturing non-zero-value spatial-nonlocal boundary conditions with directional super-diffusion) remains consistent with the sign of the fractional-diffusive flux term in the FDMs. New Lagrangian schemes are then proposed to track solute particles moving in bounded domains, where the solutions are checked against analytical or Eularian solutions available for simplified FDMs. Numerical experiments show that the particle-tracking algorithm for non-Fickian diffusion differs from Fickian diffusion in relocating the particle position around the reflective boundary, likely due to the non-local and non-symmetric fractional diffusion. For a non-zero-value Neumann or Robin boundary, a source cell with a reflective face can be applied to define the release rate of random-walking particles at the specified flux boundary. Mathematical definitions of physically meaningful nonlocal boundaries combined with bounded Lagrangian solvers in this study may provide the only viable techniques at present to quantify the impact of boundaries on anomalous diffusion, expanding the applicability of FDMs from infinite do mains to those with any size and boundary conditions.

SEXUAL EXPLOITATION AND ABUSE BY UN PEACEKEEPERS ...

African Journals Online (AJOL)

Allaiac

sexual exploitation of children by peacekeepers is particularly insidious. ... sexual exploitation and abuse should involve an understanding of the social .... The charges of sexual misconduct, and the consequent media exposure, have ..... awareness programmes such as video tapes, lectures and training manuals, designed.

Sparse Parallel MRI Based on Accelerated Operator Splitting Schemes.

Science.gov (United States)

Cai, Nian; Xie, Weisi; Su, Zhenghang; Wang, Shanshan; Liang, Dong

2016-01-01

Recently, the sparsity which is implicit in MR images has been successfully exploited for fast MR imaging with incomplete acquisitions. In this paper, two novel algorithms are proposed to solve the sparse parallel MR imaging problem, which consists of l 1 regularization and fidelity terms. The two algorithms combine forward-backward operator splitting and Barzilai-Borwein schemes. Theoretically, the presented algorithms overcome the nondifferentiable property in l 1 regularization term. Meanwhile, they are able to treat a general matrix operator that may not be diagonalized by fast Fourier transform and to ensure that a well-conditioned optimization system of equations is simply solved. In addition, we build connections between the proposed algorithms and the state-of-the-art existing methods and prove their convergence with a constant stepsize in Appendix. Numerical results and comparisons with the advanced methods demonstrate the efficiency of proposed algorithms.

High pH reversed-phase chromatography as a superior fractionation scheme compared to off-gel isoelectric focusing for complex proteome analysis.

Science.gov (United States)

Stein, Derek R; Hu, Xiaojie; McCorrister, Stuart J; Westmacott, Garrett R; Plummer, Francis A; Ball, Terry B; Carpenter, Michael S

2013-10-01

MS/MS is the technology of choice for analyzing complex protein mixtures. However, due to the intrinsic complexity and dynamic range present in higher eukaryotic proteomes, prefractionation is an important step to maximize the number of proteins identified. Off-gel IEF (OG-IEF) and high pH RP (Hp-RP) column chromatography have both been successfully utilized as a first-dimension peptide separation technique in shotgun proteomic experiments. Here, a direct comparison of the two methodologies was performed on ex vivo peripheral blood mononuclear cell lysate. In 12-fraction replicate analysis, Hp-RP resulted in more peptides and proteins identified than OG-IEF fractionation. Distributions of peptide pIs and hydropathy did not reveal any appreciable bias in either technique. Resolution, defined here as the ability to limit a specific peptide to one particular fraction, was significantly better for Hp-RP. This leads to a more uniform distribution of total and unique peptides for Hp-RP across all fractions collected. These results suggest that fractionation by Hp-RP over OG-IEF is the better choice for typical complex proteome analysis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exploitation and exploration dynamics in recessionary times

NARCIS (Netherlands)

Walrave, B.

2012-01-01

Firm performance largely depends on the ability to adapt to, and exploit, changes in the business environment. That is, firms should maintain ecological fitness by reconfiguring their resource base to cope with emerging threats and explore new opportunities, while at the same time exploiting

Main principles of developing exploitation models of semiconductor devices

Science.gov (United States)

Gradoboev, A. V.; Simonova, A. V.

2018-05-01

The paper represents primary tasks, solutions of which allow to develop the exploitation modes of semiconductor devices taking into account complex and combined influence of ionizing irradiation and operation factors. The structure of the exploitation model of the semiconductor device is presented, which is based on radiation and reliability models. Furthermore, it was shown that the exploitation model should take into account complex and combine influence of various ionizing irradiation types and operation factors. The algorithm of developing the exploitation model of the semiconductor devices is proposed. The possibility of creating the radiation model of Schottky barrier diode, Schottky field-effect transistor and Gunn diode is shown based on the available experimental data. The basic exploitation model of IR-LEDs based upon double AlGaAs heterostructures is represented. The practical application of the exploitation models will allow to output the electronic products with guaranteed operational properties.

LPTA: Location Predictive and Time Adaptive Data Gathering Scheme with Mobile Sink for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Chuan Zhu

2014-01-01

Full Text Available This paper exploits sink mobility to prolong the lifetime of sensor networks while maintaining the data transmission delay relatively low. A location predictive and time adaptive data gathering scheme is proposed. In this paper, we introduce a sink location prediction principle based on loose time synchronization and deduce the time-location formulas of the mobile sink. According to local clocks and the time-location formulas of the mobile sink, nodes in the network are able to calculate the current location of the mobile sink accurately and route data packets timely toward the mobile sink by multihop relay. Considering that data packets generating from different areas may be different greatly, an adaptive dwelling time adjustment method is also proposed to balance energy consumption among nodes in the network. Simulation results show that our data gathering scheme enables data routing with less data transmission time delay and balance energy consumption among nodes.

New approach to multishell calculations in multiple angular momentum coupling schemes

International Nuclear Information System (INIS)

Chen, J.; Novoselsky, A.; Vallieres, M.; Gilmore, R.

1989-01-01

The procedure developed recently to calculate single-shell wave functions and matrix elements for multiple angular momentum shell-model calculations is extended to the multishell case. This was based on a factorization procedure introduced by Jahn. As a consequence of the factorization, coefficients of fractional parentage between states of arbitrary symmetry must be constructed to build up single-shell N-particle states from single-shell N-1-particle states. Multishell N-particle states are built up recursively from multishell N-1-particle states by using outer-product isoscalar factors. Symmetrized multishell states in one angular momentum subspace are combined with states of conjugate symmetry in a second angular momentum subspace to construct fermion wave functions. This is done using inner-product isoscalar factors. The coefficients of fractional parentage, outer-product isoscalar factors, and inner-product isoscalar factors are computed recursively using a matrix diagonalization algorithm. Shell-model matrix elements are constructed from these factors by using a new sum over path overlaps method. This computational procedure involving factorization is substantially more efficient than computational procedures which do not exploit factorization

Application of Radiotracer Methodology for Understanding the Influence of Geochemical Fractionation on Metal Bioavailability in Estuarine Sediments

Energy Technology Data Exchange (ETDEWEB)

Fisher, N. S.; Baumann, Z. [School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY (United States)

2013-07-15

To evaluate the extent to which contaminated sediments could introduce metals into marine food chains, gamma emitting radioisotopes of arsenic, cadmium and chromium were used to study their geochemical fractionation in estuarine sediments and bioavailability to deposit feeding polychaetes. Radioisotopes were added to sediments directly or via planktonic debris and were then fractionated with a sequential extraction scheme after aging for up to 90 days. The assimilation of ingested metals was positively related to their partitioning in the two most readily extractable (labile) sediment fractions and negatively related to refractory organic fractions, oxides, and pyrite. In comparison to uptake from ingested sediment, metal uptake from pore water was negligible. A metal bioaccumulation model, modified to consider their geochemical fractionation, was found to quantitatively predict metal concentrations in benthic polychaetes better than total metal concentrations in sediment. Metals need to desorb from ingested particles into gut fluid within the polychaete gut before they can be assimilated. (author)

Study of volume fractions for stratified and annular regime in multiphase flows using gamma-rays and artificial neural network

International Nuclear Information System (INIS)

Salgado, Cesar M.; Brandao, Luis Eduardo; Pereira, Claudio M.N.A.; Ramos, Robson; Schirru, Roberto; Silva, Ademir X.

2007-01-01

This work presents methodology based on the use of nuclear technique and artificial intelligence for attainment of volume fractions in stratified and annular multiphase flow regime, oil-water-gas, very frequent in the offshore industry petroliferous. Using the principles of absorption and scattering of gamma-rays and an adequate geometry scheme of detection with two detectors and two energies measurement are gotten and they vary as changes in the volume fractions of flow regime occur. The MCNP-X code was used in order to provide the data training for artificial neural network that matched such information with the respective actual volume fractions of each material. (author)

Study of volume fractions for stratified and annular regime in multiphase flows using gamma-rays and artificial neural network

Energy Technology Data Exchange (ETDEWEB)

Salgado, Cesar M.; Brandao, Luis Eduardo; Pereira, Claudio M.N.A.; Ramos, Robson [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mail: otero@ien.gov.br; brandao@ien.gov.br; cmnap@ien.gov.br; robson@ien.gov.br; Schirru, Roberto; Silva, Ademir X. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE). Programa de Energia Nuclear (PEN)]. E-mails: ademir@con.ufrj.br; schirru@lmp.ufrj.br

2007-07-01

This work presents methodology based on the use of nuclear technique and artificial intelligence for attainment of volume fractions in stratified and annular multiphase flow regime, oil-water-gas, very frequent in the offshore industry petroliferous. Using the principles of absorption and scattering of gamma-rays and an adequate geometry scheme of detection with two detectors and two energies measurement are gotten and they vary as changes in the volume fractions of flow regime occur. The MCNP-X code was used in order to provide the data training for artificial neural network that matched such information with the respective actual volume fractions of each material. (author)

Numerical Analysis of an H1-Galerkin Mixed Finite Element Method for Time Fractional Telegraph Equation

Directory of Open Access Journals (Sweden)

Jinfeng Wang

2014-01-01

Full Text Available We discuss and analyze an H1-Galerkin mixed finite element (H1-GMFE method to look for the numerical solution of time fractional telegraph equation. We introduce an auxiliary variable to reduce the original equation into lower-order coupled equations and then formulate an H1-GMFE scheme with two important variables. We discretize the Caputo time fractional derivatives using the finite difference methods and approximate the spatial direction by applying the H1-GMFE method. Based on the discussion on the theoretical error analysis in L2-norm for the scalar unknown and its gradient in one dimensional case, we obtain the optimal order of convergence in space-time direction. Further, we also derive the optimal error results for the scalar unknown in H1-norm. Moreover, we derive and analyze the stability of H1-GMFE scheme and give the results of a priori error estimates in two- or three-dimensional cases. In order to verify our theoretical analysis, we give some results of numerical calculation by using the Matlab procedure.

Fractional vector calculus for fractional advection dispersion

Science.gov (United States)

Meerschaert, Mark M.; Mortensen, Jeff; Wheatcraft, Stephen W.

2006-07-01

We develop the basic tools of fractional vector calculus including a fractional derivative version of the gradient, divergence, and curl, and a fractional divergence theorem and Stokes theorem. These basic tools are then applied to provide a physical explanation for the fractional advection-dispersion equation for flow in heterogeneous porous media.

Quantifying the morphodynamics of river restoration schemes using Unmanned Aerial Vehicles (UAVs)

Science.gov (United States)

Williams, Richard; Byrne, Patrick; Gilles, Eric; Hart, John; Hoey, Trevor; Maniatis, George; Moir, Hamish; Reid, Helen; Ves, Nikolas

2017-04-01

River restoration schemes are particularly sensitive to morphological adjustment during the first set of high-flow events that they are subjected to. Quantifying elevation change associated with morphological adjustment can contribute to improved adaptive decision making to ensure river restoration scheme objectives are achieved. To date the relatively high cost, technical demands and challenging logistics associated with acquiring repeat, high-resolution topographic surveys has resulted in a significant barrier to monitoring the three-dimensional morphodynamics of river restoration schemes. The availability of low-cost, consumer grade Unmanned Aerial Vehicles that are capable of acquiring imagery for processing using Structure-from-Motion Multi-View Stereo (SfM MVS) photogrammetry has the potential to transform the survey the morphodynamics of river restoration schemes. Application guidance does, however, need to be developed to fully exploit the advances of UAV technology and SfM MVS processing techniques. In particular, there is a need to quantify the effect of the number and spatial distribution of ground targets on vertical error. This is particularly significant because vertical errors propagate when mapping morphological change, and thus determine the evidence that is available for decision making. This presentation presents results from a study that investigated how the number and spatial distribution of targets influenced vertical error, and then used the findings to determine survey protocols for a monitoring campaign that has quantified morphological change across a number of restoration schemes. At the Swindale river restoration scheme, Cumbria, England, 31 targets were distributed across a 700 m long reach and the centre of each target was surveyed using RTK-GPS. Using the targets as General Control Points (GCPs) or checkpoints, they were divided into three different spatial patterns (centre, edge and random) and used for processing images acquired

Colour schemes

DEFF Research Database (Denmark)

van Leeuwen, Theo

2013-01-01

This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation.......This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation....

Some Exploitation Properties of Wood Plastic Hybrid Composites Based on Polypropylene and Plywood Production Waste

Science.gov (United States)

Kajaks, Janis; Kalnins, Karlis; Uzulis, Sandris; Matvejs, Juris

2015-12-01

During the last 20-30 years many researchers have paid attention to the studies of properties of thewood polymer composites (WPC). A lot of works are closely related to investigations of exploitation properties of wood fibres or wood flour containing polyolefine composites [1, 2]. The most useful from wide selection of polyolefines are polypropylenes, but timber industry waste materials comprising lignocellulose fibres are often used as reinforcement of WPC [3-12]. Plywood industry is not an exception - part of waste materials (by-products) are used for heat energy, i.e. burned. In this work we have approbated reinforcing of polypropylene (PP) with one of the plywood industry by-products, such as birch plywood sawdust (PSWD),which containswood fibre fractions with different length [13]. The main fraction (50%) includes fibres with length l = 0.5 - 1 mm. Our previous study [13] has confirmed that PSWD is a promising filler for PP reinforcing. Addition of PSWD up to 40-50 wt.% has increased WPC tensile and flexural modulus, but decreased deformation ability of PP matrix, impact strength, water resistance and fluidity of composite melts. It was shown [13] that modification of the composites with interfacial modifier - coupling agent maleated polypropylene (MAPP content up to 5-7 wt.%) considerably improved all the abovementioned properties. SEM investigations also confirmed positive action of coupling agent on strengthening of adhesion interaction between components wood and PP matrix. Another way how to make better properties of the WPC is to form hybridcomposites [1, 14-24]. Very popular WPC modifiers are nanoparticle additions like organonanoclays, which increase WPC physical-mechanical properties - microhardness, water resistance and diminish barrier properties and combustibility [1, 2, 14-17, 19, 20]. The goal of this study was to investigate organonanoclays influence on plywood production industry by-product birch plywood sawdust (PSWD) containing

Scheme of energy collective services; Schema de services collectifs de l'energie

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The scheme of collective energy services aims at facilitating and valorizing the contribution of the national organizations to the national energy plan and to the durable development of the country. The scheme comprises three main goals: defining the exploitation goals of local renewable energy resources and the goals of rational energy uses which can contribute to the national energy independence, to the security of supplies and to the abatement of the greenhouse effect; evaluating the foreseeable energy needs of regions and their energy production potentiality, their energy saving possibilities and their energy transportation needs; and finally, determining the conditions in which the government and the national organizations will be able to favor the energy saving actions and the production and use of renewable energies taking into account their impact on employment and their long-term financial consequences. This document is organized in five parts: 1 - status, stakes and perspectives: energy demand perspectives at the 2010-2020 vista, potentialities of energy saving and renewable energy sources development, implication of the international commitment of France in the fight against greenhouse effect; 2 - action means for new measures: buildings and accommodations, transportation sector, industry sector, mastery of electricity demand, development of renewable energy sources, decentralized energy production, energy storage, transport and distribution, economic tools and public means of sustain; 3 - follow up of the scheme of energy collective services; 4 - analysis of regional contributions; 5 - appendixes and maps. (J.S.)

Chapter 2. Peculiarities of radioactive particle formation and isotope fractionation resulted from underground nuclear explosions

International Nuclear Information System (INIS)

1996-01-01

Radioactive particles, forming terrain fallouts from underground nuclear explosion differ sufficiently from radioactive particles, produced by atmospheric nuclear explosions. Patterns of underground nuclear explosion development, release of radioactivity to the atmosphere, formation of a cloud and base surge, peculiarities of formed radioactive particles, data on isotope fractionation in radioactive particles are presented. Scheme of particle activation, resulted from underground explosions is given

Packaging of Sin Goods - Commitment or Exploitation?

DEFF Research Database (Denmark)

Nafziger, Julia

to such self-control problems, and possibly exploit them, by offering different package sizes. In a competitive market, either one or three (small, medium and large) packages are offered. In contrast to common intuition, the large, and not the small package is a commitment device. The latter serves to exploit...

Measurement of wetted area fraction in subcooled pool boiling of water using infrared thermography

International Nuclear Information System (INIS)

Kim, Hyungdae; Park, Youngjae; Buongiorno, Jacopo

2013-01-01

The wetted area fraction in subcooled pool boiling of water at atmospheric pressure is measured using the DEPIcT (DEtection of Phase by Infrared Thermography) technique. DEPIcT exploits the contrast in infrared (IR) light emissions between wet and dry areas on the surface of an IR-transparent heater to visualize the instantaneous distribution of the liquid and gas phases in contact with the heater surface. In this paper time-averaged wetted area fraction data in nucleate boiling are reported as functions of heat flux (from 30% up to 100% of the Critical Heat Flux) and subcooling (ΔT sub = 0, 5, 10, 30 and 50 °C). The results show that the wetted area fraction monotonically decreases with increasing heat flux and increases with increasing subcooling: both trends are expected. The range of time-averaged wetted area fractions is from 90%, at low heat flux and high subcooling, to 50% at high heat flux (right before CHF) and low subcooling. It is also shown that the dry areas are periodically rewetted by liquid sloshing on the surface at any subcooling and heat flux; however, the dry areas expand irreversibly at CHF

Particle-hole symmetry and composite fermions in fractional quantum Hall states

Science.gov (United States)

Nguyen, Dung Xuan; Golkar, Siavash; Roberts, Matthew M.; Son, Dam Thanh

2018-05-01

We study fractional quantum Hall states at filling fractions in the Jain sequences using the framework of composite Dirac fermions. Synthesizing previous work, we write an effective field theory consistent with all symmetry requirements, including Galilean invariance and particle-hole symmetry. Employing a Fermi-liquid description, we demonstrate the appearance of the Girvin-Macdonald-Platzman algebra and compute the dispersion relation of neutral excitations and various response functions. Our results satisfy requirements of particle-hole symmetry. We show that while the dispersion relation obtained from the modified random-phase approximation (MRPA) of the Halperin-Lee-Read (HLR) theory is particle-hole symmetric, correlation functions obtained from this scheme are not. The results of the Dirac theory are shown to be consistent with the Haldane bound on the projected structure factor, while those of the MPRA of the HLR theory violate it.

Numerical Identification of Multiparameters in the Space Fractional Advection Dispersion Equation by Final Observations

Directory of Open Access Journals (Sweden)

Dali Zhang

2012-01-01

Full Text Available This paper deals with an inverse problem for identifying multiparameters in 1D space fractional advection dispersion equation (FADE on a finite domain with final observations. The parameters to be identified are the fractional order, the diffusion coefficient, and the average velocity in the FADE. The forward problem is solved by a finite difference scheme, and then an optimal perturbation regularization algorithm is introduced to determine the three parameters simultaneously. Numerical inversions are performed both with the accurate data and noisy data, and several factors having influences on realization of the algorithm are discussed. The inversion solutions are in good approximations to the exact solutions demonstrating the efficiency of the proposed algorithm.

Mental Task Classification Scheme Utilizing Correlation Coefficient Extracted from Interchannel Intrinsic Mode Function.

Science.gov (United States)

Rahman, Md Mostafizur; Fattah, Shaikh Anowarul

2017-01-01

In view of recent increase of brain computer interface (BCI) based applications, the importance of efficient classification of various mental tasks has increased prodigiously nowadays. In order to obtain effective classification, efficient feature extraction scheme is necessary, for which, in the proposed method, the interchannel relationship among electroencephalogram (EEG) data is utilized. It is expected that the correlation obtained from different combination of channels will be different for different mental tasks, which can be exploited to extract distinctive feature. The empirical mode decomposition (EMD) technique is employed on a test EEG signal obtained from a channel, which provides a number of intrinsic mode functions (IMFs), and correlation coefficient is extracted from interchannel IMF data. Simultaneously, different statistical features are also obtained from each IMF. Finally, the feature matrix is formed utilizing interchannel correlation features and intrachannel statistical features of the selected IMFs of EEG signal. Different kernels of the support vector machine (SVM) classifier are used to carry out the classification task. An EEG dataset containing ten different combinations of five different mental tasks is utilized to demonstrate the classification performance and a very high level of accuracy is achieved by the proposed scheme compared to existing methods.

Modelling and simulation of a dynamical system with the Atangana-Baleanu fractional derivative

Science.gov (United States)

Owolabi, Kolade M.

2018-01-01

In this paper, we model an ecological system consisting of a predator and two preys with the newly derived two-step fractional Adams-Bashforth method via the Atangana-Baleanu derivative in the Caputo sense. We analyze the dynamical system for correct choice of parameter values that are biologically meaningful. The local analysis of the main model is based on the application of qualitative theory for ordinary differential equations. By using the fixed point theorem idea, we establish the existence and uniqueness of the solutions. Convergence results of the new scheme are verified in both space and time. Dynamical wave phenomena of solutions are verified via some numerical results obtained for different values of the fractional index, which have some interesting ecological implications.

A Theory of Exploitative Child Labor

OpenAIRE

Carol Ann Rogers; Kenneth A. Swinnerton

2003-01-01

Child labor laws should aim to protect children who work, instead of trying to remove children from work. In this paper, we identify an instance when the risk of exploitation lowers the expected bene…t of child labor to the child,and therefore suppresses child labor force participation. Targeted legal intervention that lowers or removes the risk of exploitation raises child participation in the labor market, child welfare, and overall societal welfare. Targeting on child labor more broadly ma...

Dynamic leaching and fractionation of trace elements from environmental solids exploiting a novel circulating-flow platform.

Science.gov (United States)

Mori, Masanobu; Nakano, Koji; Sasaki, Masaya; Shinozaki, Haruka; Suzuki, Shiho; Okawara, Chitose; Miró, Manuel; Itabashi, Hideyuki

2016-02-01

A dynamic flow-through microcolumn extraction system based on extractant re-circulation is herein proposed as a novel analytical approach for simplification of bioaccessibility tests of trace elements in sediments. On-line metal leaching is undertaken in the format of all injection (AI) analysis, which is a sequel of flow injection analysis, but involving extraction under steady-state conditions. The minimum circulation times and flow rates required to determine the maximum bioaccessible pools of target metals (viz., Cu, Zn, Cd, and Pb) from lake and river sediment samples were estimated using Tessier's sequential extraction scheme and an acid single extraction test. The on-line AIA method was successfully validated by mass balance studies of CRM and real sediment samples. Tessier's test in on-line AI format demonstrated to be carried out by one third of extraction time (6h against more than 17 h by the conventional method), with better analytical precision (15% by the conventional method) and significant decrease in blank readouts as compared with the manual batch counterpart. Copyright © 2015 Elsevier B.V. All rights reserved.

Rationalising predictors of child sexual exploitation and sex-trading.

Science.gov (United States)

Klatt, Thimna; Cavner, Della; Egan, Vincent

2014-02-01

Although there is evidence for specific risk factors leading to child sexual exploitation and prostitution, these influences overlap and have rarely been examined concurrently. The present study examined case files for 175 young persons who attended a voluntary organization in Leicester, United Kingdom, which supports people who are sexually exploited or at risk of sexual exploitation. Based on the case files, the presence or absence of known risk factors for becoming a sex worker was coded. Data were analyzed using t-test, logistic regression, and smallest space analysis. Users of the voluntary organization's services who had been sexually exploited exhibited a significantly greater number of risk factors than service users who had not been victims of sexual exploitation. The logistic regression produced a significant model fit. However, of the 14 potential predictors--many of which were associated with each other--only four variables significantly predicted actual sexual exploitation: running away, poverty, drug and/or alcohol use, and having friends or family members in prostitution. Surprisingly, running away was found to significantly decrease the odds of becoming involved in sexual exploitation. Smallest space analysis of the data revealed 5 clusters of risk factors. Two of the clusters, which reflected a desperation and need construct and immature or out-of-control lifestyles, were significantly associated with sexual exploitation. Our research suggests that some risk factors (e.g. physical and emotional abuse, early delinquency, and homelessness) for becoming involved in sexual exploitation are common but are part of the problematic milieu of the individuals affected and not directly associated with sex trading itself. Our results also indicate that it is important to engage with the families and associates of young persons at risk of becoming (or remaining) a sex worker if one wants to reduce the numbers of persons who engage in this activity. Copyright �

Fractional vector calculus and fractional Maxwell's equations

International Nuclear Information System (INIS)

Tarasov, Vasily E.

2008-01-01

The theory of derivatives and integrals of non-integer order goes back to Leibniz, Liouville, Grunwald, Letnikov and Riemann. The history of fractional vector calculus (FVC) has only 10 years. The main approaches to formulate a FVC, which are used in the physics during the past few years, will be briefly described in this paper. We solve some problems of consistent formulations of FVC by using a fractional generalization of the Fundamental Theorem of Calculus. We define the differential and integral vector operations. The fractional Green's, Stokes' and Gauss's theorems are formulated. The proofs of these theorems are realized for simplest regions. A fractional generalization of exterior differential calculus of differential forms is discussed. Fractional nonlocal Maxwell's equations and the corresponding fractional wave equations are considered

Modified Projective Synchronization between Different Fractional-Order Systems Based on Open-Plus-Closed-Loop Control and Its Application in Image Encryption

Directory of Open Access Journals (Sweden)

Hongjuan Liu

2014-01-01

Full Text Available A new general and systematic coupling scheme is developed to achieve the modified projective synchronization (MPS of different fractional-order systems under parameter mismatch via the Open-Plus-Closed-Loop (OPCL control. Based on the stability theorem of linear fractional-order systems, some sufficient conditions for MPS are proposed. Two groups of numerical simulations on the incommensurate fraction-order system and commensurate fraction-order system are presented to justify the theoretical analysis. Due to the unpredictability of the scale factors and the use of fractional-order systems, the chaotic data from the MPS is selected to encrypt a plain image to obtain higher security. Simulation results show that our method is efficient with a large key space, high sensitivity to encryption keys, resistance to attack of differential attacks, and statistical analysis.

Shale gas exploitation: Status, problems and prospect

Directory of Open Access Journals (Sweden)

Shiqian Wang

2018-02-01

Full Text Available Over the past five years, great progress has been made in shale gas exploitation, which has become the most driving force for global gas output growth. Hydrocarbon extraction from shale helps drive the USA on the road to energy independence. Besides, shale oil & gas production has been kept in a sustained growth by continuous improvement in drilling efficiency and well productivity in the case of tumbling oil prices and rig counts. Shale gas reserves and production have been in a rapid growth in China owing to the Lower Paleozoic Wufeng and Longmaxi shale gas exploitation in the Sichuan Basin, which has become an important sector for the future increment of gas reserves and output in China. However, substantial progress has been made neither in non-marine shale gas exploitation as previously expected nor in the broad complicated tectonic areas in South China for which a considerable investment was made. Analysis of the basic situation and issues in domestic shale gas development shows that shale gas exploitation prospects are constrained by many problems in terms of resources endowment, horizontal well fracturing technology, etc. especially in non-marine shale deposits and complicated tectonic areas in South China where hot shales are widely distributed but geological structures are found severely deformed and over matured. Discussion on the prospects shows that the sustained and steady growth in shale gas reserves and production capacity in the coming years lies in the discovery and supersession of new shale plays in addition to Wufeng and Longmaxi shale plays, and that a technological breakthrough in ultra-high-pressure and ultra-deep (over 3500 m buried in the Sichuan Basin marine shale gas exploitation is the key and hope. Keywords: Shale gas, Exploitation, Marine facies, Hot shale, Resource endowment, Sichuan Basin, South China, Complicated tectonic area, Gas play

A delay fractioning approach to global synchronization of delayed complex networks with stochastic disturbances

International Nuclear Information System (INIS)

Wang Yao; Wang Zidong; Liang Jinling

2008-01-01

In this Letter, the synchronization problem is investigated for a class of stochastic complex networks with time delays. By utilizing a new Lyapunov functional form based on the idea of 'delay fractioning', we employ the stochastic analysis techniques and the properties of Kronecker product to establish delay-dependent synchronization criteria that guarantee the globally asymptotically mean-square synchronization of the addressed delayed networks with stochastic disturbances. These sufficient conditions, which are formulated in terms of linear matrix inequalities (LMIs), can be solved efficiently by the LMI toolbox in Matlab. The main results are proved to be much less conservative and the conservatism could be reduced further as the number of delay fractioning gets bigger. A simulation example is exploited to demonstrate the advantage and applicability of the proposed result

Fractional Number Operator and Associated Fractional Diffusion Equations

Science.gov (United States)

Rguigui, Hafedh

2018-03-01

In this paper, we study the fractional number operator as an analog of the finite-dimensional fractional Laplacian. An important relation with the Ornstein-Uhlenbeck process is given. Using a semigroup approach, the solution of the Cauchy problem associated to the fractional number operator is presented. By means of the Mittag-Leffler function and the Laplace transform, we give the solution of the Caputo time fractional diffusion equation and Riemann-Liouville time fractional diffusion equation in infinite dimensions associated to the fractional number operator.

SU-E-J-105: Stromal-Epithelial Responses to Fractionated Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Qayyum, M [Little Company of Mary Hospital, Ever Green Park, IL (United States)

2014-06-01

Purpose: The stromal-epithelial-cell interactions that are responsible for directing normal breast-tissue development and maintenance play a central role in the progression of breast cancer. In the present study, we developed three-dimensional (3-D) cell co-cultures used to study cancerous mammary cell responses to fractionated radiotherapy. In particular, we focused on the role of the reactive stroma in determining the therapeutic ratio for postsurgical treatment. Methods: Cancerous human mammary epithelial cells were cultured in a 3-D collagen matrix with human fibroblasts stimulated by various concentrations of transforming growth factor beta 1 (TGF-β1). These culture samples were designed to model the post-lumpectomy mammary stroma in the presence of residual cancer cells. We tracked over time the changes in medium stiffness, fibroblast-cell activation (conversion to cancer activated fibroblasts (CAF)), and proliferation of both cell types under a variety of fractionated radiotherapy protocols. Samples were exposed to 6 MV X-rays from a linear accelerator in daily fraction sizes of 90, 180 and 360 cGy over five days in a manner consistent with irradiation exposure during radiotherapy. Results: We found in fractionation studies with fibroblasts and CAF that higher doses per fraction may be more effective early on in deactivating cancer-harboring cellular environments. Higher-dose fraction schemes inhibit contractility in CAF and prevent differentiation of fibroblasts, thereby metabolically uncoupling tumor cells from their surrounding stroma. Yet, over a longer time period, the higher dose fractions may slow wound healing and increase ECM stiffening that could stimulate proliferation of surviving cancer cells. Conclusion: The findings suggest that dose escalation to the region with residual disease can deactivate the reactive stroma, thus minimizing the cancer promoting features of the cellular environment. Large-fraction irradiation may be used to sterilize

SU-E-J-105: Stromal-Epithelial Responses to Fractionated Radiotherapy

International Nuclear Information System (INIS)

Qayyum, M

2014-01-01

Purpose: The stromal-epithelial-cell interactions that are responsible for directing normal breast-tissue development and maintenance play a central role in the progression of breast cancer. In the present study, we developed three-dimensional (3-D) cell co-cultures used to study cancerous mammary cell responses to fractionated radiotherapy. In particular, we focused on the role of the reactive stroma in determining the therapeutic ratio for postsurgical treatment. Methods: Cancerous human mammary epithelial cells were cultured in a 3-D collagen matrix with human fibroblasts stimulated by various concentrations of transforming growth factor beta 1 (TGF-β1). These culture samples were designed to model the post-lumpectomy mammary stroma in the presence of residual cancer cells. We tracked over time the changes in medium stiffness, fibroblast-cell activation (conversion to cancer activated fibroblasts (CAF)), and proliferation of both cell types under a variety of fractionated radiotherapy protocols. Samples were exposed to 6 MV X-rays from a linear accelerator in daily fraction sizes of 90, 180 and 360 cGy over five days in a manner consistent with irradiation exposure during radiotherapy. Results: We found in fractionation studies with fibroblasts and CAF that higher doses per fraction may be more effective early on in deactivating cancer-harboring cellular environments. Higher-dose fraction schemes inhibit contractility in CAF and prevent differentiation of fibroblasts, thereby metabolically uncoupling tumor cells from their surrounding stroma. Yet, over a longer time period, the higher dose fractions may slow wound healing and increase ECM stiffening that could stimulate proliferation of surviving cancer cells. Conclusion: The findings suggest that dose escalation to the region with residual disease can deactivate the reactive stroma, thus minimizing the cancer promoting features of the cellular environment. Large-fraction irradiation may be used to sterilize

LevelScheme: A level scheme drawing and scientific figure preparation system for Mathematica

Science.gov (United States)

Caprio, M. A.

2005-09-01

LevelScheme is a scientific figure preparation system for Mathematica. The main emphasis is upon the construction of level schemes, or level energy diagrams, as used in nuclear, atomic, molecular, and hadronic physics. LevelScheme also provides a general infrastructure for the preparation of publication-quality figures, including support for multipanel and inset plotting, customizable tick mark generation, and various drawing and labeling tasks. Coupled with Mathematica's plotting functions and powerful programming language, LevelScheme provides a flexible system for the creation of figures combining diagrams, mathematical plots, and data plots. Program summaryTitle of program:LevelScheme Catalogue identifier:ADVZ Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVZ Operating systems:Any which supports Mathematica; tested under Microsoft Windows XP, Macintosh OS X, and Linux Programming language used:Mathematica 4 Number of bytes in distributed program, including test and documentation:3 051 807 Distribution format:tar.gz Nature of problem:Creation of level scheme diagrams. Creation of publication-quality multipart figures incorporating diagrams and plots. Method of solution:A set of Mathematica packages has been developed, providing a library of level scheme drawing objects, tools for figure construction and labeling, and control code for producing the graphics.

Exploiting nonlinear dynamics in a coupled-core fluxgate magnetometer

International Nuclear Information System (INIS)

Bulsara, Adi R; In, Visarath; Kho, Andy; Longhini, Patrick; Neff, Joe; Anderson, Gregory; Obra, Christopher; Palacios, Antonio; Baglio, Salvatore; Ando, Bruno

2008-01-01

Unforced bistable dynamical systems having dynamics of the general form τ F x-dot (t)=-∇ x U(x) cannot oscillate (i.e. switch between their stable attractors). However, a number of such systems subject to carefully crafted coupling schemes have been shown to exhibit oscillatory behavior under carefully chosen operating conditions. This behavior, in turn, affords a new mechanism for the detection and quantification of target signals having magnitude far smaller than the energy barrier height in the potential energy function U(x) for a single (uncoupled) element. The coupling-induced oscillations are a feature that appears to be universal in systems described by bi- or multi-stable potential energy functions U(x), and are being exploited in a new class of dynamical sensors being developed by us. In this work we describe one of these devices, a coupled-core fluxgate magnetometer (CCFM), whose operation is underpinned by this dynamic behavior. We provide an overview of the underlying dynamics and, also, quantify the performance of our test device; in particular, we provide a quantitative performance comparison to a conventional (single-core) fluxgate magnetometer via a 'resolution' parameter that embodies the device sensitivity (the slope of its input–output transfer characteristic) as well as the noise floor

TU-H-CAMPUS-TeP1-01: Variable-Beam Fractionation for SAbR

Energy Technology Data Exchange (ETDEWEB)

Modiri, A; Sawant, A [University of Maryland School of Medicine, Baltimore, MD (United States)

2016-06-15

Purpose: In current conventionally-fractionated as well as hypofractionated 3D conformal radiotherapy (CRT), the same beam arrangement is employed from fraction to fraction. We challenge this notion and postulate that by varying the beam arrangement between fractions we can achieve greater sparing of organs at risk (OARs) while maintaining PTV coverage. We use an inverse planning strategy using a swarm intelligence-based global optimization algorithm to exploit the additional degree of freedom represented by inter-fractional variation in beam angles. Methods: To evaluate our variable-beam fractionation (VBF) method, a 10-beam ITV-based conformal stereotactic ablative radiotherapy (CRT-SAbR) plan was optimized. In the clinical plan, 54 Gy was delivered to a 41cc lung tumor over 3 fractions. In VBF, each original clinically-assigned beam was multiplied to a bundle of n α-degree-spaced beams, n being number of fractions. Selection of α was a compromise between retaining similar tumor irradiation and separating inline OAR sub-regions. We optimized the beam fluence weights setting an upper limit for beam delivery duration (and implicitly, monitor units) along with clinical organ-based dose-volume constraints. Zero weights were allowed so that the optimization algorithm could remove unnecessary beams. All fractions in final plan had to deliver identical monitor units (MU) while satisfying a soft constraint on having no more than one beam from every n-beam bundle in each fraction. α was 10 degrees and the dose rate was 600 MU/min. Results: The VBF plan achieved significantly superior OAR sparing compared to the clinical internal target volume (ITV)-based plan. Setting maximum beam delivery duration to 13 seconds (well within breath-hold range), Esophagus Dmax, Heart Dmax, Spinal cord Dmax and Lung V13 were improved by 25%, 81%, 0% and 27%, respectively. Conclusion: We investigated a simple approach to inter-fractional VBF planning and demonstrated its potential in

Fractional Processes and Fractional-Order Signal Processing Techniques and Applications

CERN Document Server

Sheng, Hu; Qiu, TianShuang

2012-01-01

Fractional processes are widely found in science, technology and engineering systems. In Fractional Processes and Fractional-order Signal Processing, some complex random signals, characterized by the presence of a heavy-tailed distribution or non-negligible dependence between distant observations (local and long memory), are introduced and examined from the ‘fractional’ perspective using simulation, fractional-order modeling and filtering and realization of fractional-order systems. These fractional-order signal processing (FOSP) techniques are based on fractional calculus, the fractional Fourier transform and fractional lower-order moments. Fractional Processes and Fractional-order Signal Processing: • presents fractional processes of fixed, variable and distributed order studied as the output of fractional-order differential systems; • introduces FOSP techniques and the fractional signals and fractional systems point of view; • details real-world-application examples of FOSP techniques to demonstr...

The possibilities of exploitation of Serbian thermomineral waters

International Nuclear Information System (INIS)

Jovanovic, L.

2002-01-01

Global ecological problem of petrol resources deficit caused an intensive search of alternative energy sources. Deficit of conventional energy fluids in Yugoslavia requires serious efforts to create a program of alternative energy sources exploitation. Geothermal energy represents an important energetic source for the countries with poor energy resources. Geothermal energy can become the basis for economic development. At present these geothermal resources are not being exploited in Yugoslavia. The possibilities of effective exploitation of thermal and thermomineral water resources in Yugoslavia are presented in this paper

Reconstructive schemes for variational iteration method within Yang-Laplace transform with application to fractal heat conduction problem

Directory of Open Access Journals (Sweden)

Liu Chun-Feng

2013-01-01

Full Text Available A reconstructive scheme for variational iteration method using the Yang-Laplace transform is proposed and developed with the Yang-Laplace transform. The identification of fractal Lagrange multiplier is investigated by the Yang-Laplace transform. The method is exemplified by a fractal heat conduction equation with local fractional derivative. The results developed are valid for a compact solution domain with high accuracy.

Development of a simple unified volatility-based scheme (SUVS for secondary organic aerosol formation using genetic algorithms

Directory of Open Access Journals (Sweden)

A. G. Xia

2011-07-01

Full Text Available A new method is proposed to simplify complex atmospheric chemistry reaction schemes, while preserving SOA formation properties, using genetic algorithms. The method is first applied in this study to the gas-phase α-pinene oxidation scheme. The simple unified volatility-based scheme (SUVS reflects the multi-generation evolution of chemical species from a near-explicit master chemical mechanism (MCM and, at the same time, uses the volatility-basis set speciation for condensable products. The SUVS also unifies reactions between SOA precursors with different oxidants under different atmospheric conditions. A total of 412 unknown parameters (product yields of parameterized products, reaction rates, etc. from the SUVS are estimated by using genetic algorithms operating on the detailed mechanism. The number of organic species was reduced from 310 in the detailed mechanism to 31 in the SUVS. Output species profiles, obtained from the original subset of the MCM reaction scheme for α-pinene oxidation, are reproduced with maximum fractional error at 0.10 for scenarios under a wide range of ambient HC/NO_x conditions. Ultimately, the same SUVS with updated parameters could be used to describe the SOA formation from different precursors.

Packet reversed packet combining scheme

International Nuclear Information System (INIS)

Bhunia, C.T.

2006-07-01

The packet combining scheme is a well defined simple error correction scheme with erroneous copies at the receiver. It offers higher throughput combined with ARQ protocols in networks than that of basic ARQ protocols. But packet combining scheme fails to correct errors when the errors occur in the same bit locations of two erroneous copies. In the present work, we propose a scheme that will correct error if the errors occur at the same bit location of the erroneous copies. The proposed scheme when combined with ARQ protocol will offer higher throughput. (author)

Thermal Property Engineering: Exploiting the Properties of Ceramic Nanocomposites

Science.gov (United States)

2018-03-01

ARL-TR-8308 ● MAR 2018 US Army Research Laboratory Thermal Property Engineering : Exploiting the Properties of Ceramic...return it to the originator. ARL-TR-8308 ● MAR 2018 US Army Research Laboratory Thermal Property Engineering : Exploiting the...2015 – Dec 31 2017 4. TITLE AND SUBTITLE Thermal Property Engineering : Exploiting the Properties of Ceramic Nanocomposites 5a. CONTRACT NUMBER 5b

Rethinking exploitation: a process-centered account.

Science.gov (United States)

Jansen, Lynn A; Wall, Steven

2013-12-01

Exploitation has become an important topic in recent discussions of biomedical and research ethics. This is due in no small measure to the influence of Alan Wertheimer's path-breaking work on the subject. This paper presents some objections to Wertheimer's account of the concept. The objections attempt to show that his account places too much emphasis on outcome-based considerations and too little on process-based considerations. Building on these objections, the paper develops an alternative process-centered account of the concept. This alternative account of exploitation takes as its point of departure the broadly Kantian notion that it is wrong to use another as an instrument for the advancement of one's own ends. It sharpens this slippery notion and adds a number of refinements to it. The paper concludes by arguing that process-centered accounts of exploitation better illuminate the ethical challenges posed by research on human subjects than outcome-centered accounts.

Revisiting of Channel Access Mechanisms in Mobile Wireless Networks through Exploiting Physical Layer Technologies

Directory of Open Access Journals (Sweden)

Junmei Yao

2018-01-01

Full Text Available The wireless local area networks (WLANs have been widely deployed with the rapid development of mobile devices and have further been brought into new applications with infrastructure mobility due to the growth of unmanned aerial vehicles (UAVs. However, the WLANs still face persistent challenge on increasing the network throughput to meet the customer’s requirement and fight against the node mobility. Interference is a well-known issue that would degrade the network performance due to the broadcast characteristics of the wireless signals. Moreover, with infrastructure mobility, the interference becomes the key obstacle in pursuing the channel capacity. Legacy interference management mechanism through the channel access control in the MAC layer design of the 802.11 standard has some well-known drawbacks, such as exposed and hidden terminal problems, inefficient rate adaptation, and retransmission schemes, making the efficient interference management an everlasting research topic over the years. Recently, interference management through exploiting physical layer mechanisms has attracted much research interest and has been proven to be a promising way to improve the network throughput, especially under the infrastructure mobility scenarios which provides more indicators for node dynamics. In this paper, we introduce a series of representative physical layer techniques and analyze how they are exploited for interference management to improve the network performance. We also provide some discussions about the research challenges and give potential future research topics in this area.

TU-AB-303-12: Towards Inter and Intra Fraction Plan Adaptation for the MR-Linac

International Nuclear Information System (INIS)

Kontaxis, C; Bol, G; Lagendijk, J; Raaymakers, B

2015-01-01

Purpose: To develop a new sequencer for IMRT that during treatment can account for anatomy changes provided by online and real-time MRI. This sequencer employs a novel inter and intra fraction scheme that converges to the prescribed dose without a final segment weight optimization (SWO) and enables immediate optimization and delivery of radiation adapted to the deformed anatomy. Methods: The sequencer is initially supplied with a voxel-based dose prescription and during the optimization iteratively generates segments that provide this prescribed dose. Every iteration selects the best segment for the current anatomy state, calculates the dose it will deliver, warps it back to the reference prescription grid and subtracts it from the remaining prescribed dose. This process continues until a certain percentage of dose or a number of segments has been delivered. The anatomy changes that occur during treatment require that convergence is achieved without a final SWO. This is resolved by adding the difference between the prescribed and delivered dose up to this fraction to the prescription of the subsequent fraction. This process is repeated for all fractions of the treatment. Results: Two breast cases were selected to stress test the pipeline by producing artificial inter and intra fraction anatomy deformations using a combination of incrementally applied rigid transformations. The dose convergence of the adaptive scheme over the entire treatment, relative to the prescribed dose, was on average 8.6% higher than the static plans delivered to the respective deformed anatomies and only 1.6% less than the static segment weighted plans on the static anatomy. Conclusion: This new adaptive sequencing strategy enables dose convergence without the need of SWO while adapting the plan to intermediate anatomies, which is a prerequisite for online plan adaptation. We are now testing our pipeline on prostate cases using clinical anatomy deformation data from our department. This work

A full quantum network scheme

International Nuclear Information System (INIS)

Ma Hai-Qiang; Wei Ke-Jin; Yang Jian-Hui; Li Rui-Xue; Zhu Wu

2014-01-01

We present a full quantum network scheme using a modified BB84 protocol. Unlike other quantum network schemes, it allows quantum keys to be distributed between two arbitrary users with the help of an intermediary detecting user. Moreover, it has good expansibility and prevents all potential attacks using loopholes in a detector, so it is more practical to apply. Because the fiber birefringence effects are automatically compensated, the scheme is distinctly stable in principle and in experiment. The simple components for every user make our scheme easier for many applications. The experimental results demonstrate the stability and feasibility of this scheme. (general)

SLFP: a stochastic linear fractional programming approach for sustainable waste management.

Science.gov (United States)

Zhu, H; Huang, G H

2011-12-01

A stochastic linear fractional programming (SLFP) approach is developed for supporting sustainable municipal solid waste management under uncertainty. The SLFP method can solve ratio optimization problems associated with random information, where chance-constrained programming is integrated into a linear fractional programming framework. It has advantages in: (1) comparing objectives of two aspects, (2) reflecting system efficiency, (3) dealing with uncertainty expressed as probability distributions, and (4) providing optimal-ratio solutions under different system-reliability conditions. The method is applied to a case study of waste flow allocation within a municipal solid waste (MSW) management system. The obtained solutions are useful for identifying sustainable MSW management schemes with maximized system efficiency under various constraint-violation risks. The results indicate that SLFP can support in-depth analysis of the interrelationships among system efficiency, system cost and system-failure risk. Copyright © 2011 Elsevier Ltd. All rights reserved.

Transmission usage cost allocation schemes

International Nuclear Information System (INIS)

Abou El Ela, A.A.; El-Sehiemy, R.A.

2009-01-01

This paper presents different suggested transmission usage cost allocation (TCA) schemes to the system individuals. Different independent system operator (ISO) visions are presented using the proportional rata and flow-based TCA methods. There are two proposed flow-based TCA schemes (FTCA). The first FTCA scheme generalizes the equivalent bilateral exchanges (EBE) concepts for lossy networks through two-stage procedure. The second FTCA scheme is based on the modified sensitivity factors (MSF). These factors are developed from the actual measurements of power flows in transmission lines and the power injections at different buses. The proposed schemes exhibit desirable apportioning properties and are easy to implement and understand. Case studies for different loading conditions are carried out to show the capability of the proposed schemes for solving the TCA problem. (author)

Radial distribution of power starting from the reactivity using nodal schemes of second and third order

International Nuclear Information System (INIS)

Delfin L, A.; Alonso V, G.; Valle G, E. del

2003-01-01

In this work two nodal schemes of finite element are presented, one of second and the other of third order of accurate that allow to determine the radial distribution of power starting from the corresponding reactivities.The schemes here developed were obtained taking as starting point the equation developed by Driscoll et al, the one which is based on the diffusion approach of 1-1/2 energy groups. This equation relates the power fraction of an assemble with their reactivity and with the power fractions and reactivities of the assemblies that its surround it. Driscoll and collaborators they solve in form approximate such equation supposing that the reactivity of each assemble it is but a lineal function of the burnt one of the fuel. The spatial approach carries out it with the classic technique of finite differences centered in mesh. Nevertheless that the algebraic system to which its arrive it can be solved without more considerations introduce some additional suppositions and adjustment parameters that it allows them to predict results comparable to those contributed by three dimensions analysis and this way to reduce the one obtained error when its compare their results with those of a production code like CASMO. Also in the two schemes that here are presented the same approaches of Driscoll were used being obtained errors of the one 10% and of 5% for the second schemes and third order respectively for a test case that it was built starting from data of the Cycle 1 of the Unit 1 of the Laguna Verde Nucleo electric plant. These errors its were obtained when comparing with a computer program based on the matrix response method. It is sought to have this way a quick and efficient tool for the multicycle analysis in the fuel management. However, this model presents problems in the appropriate prediction of the average burnt of the nucleus and of the burnt one by lot. (Author)

Skin reactions of rat feet exposed to multiple fractions of X rays per day

International Nuclear Information System (INIS)

Rongen, E. van

1983-01-01

The right hind feet of female WAG/Rij rats were irradiated with multiple fractions per day (4 x 2 Gy daily), with daily fractions of 3 Gy and with single doses of 300 kV X-rays. Acute reactions were scored 5 times per week until the reactions disappeared. Mean scores were derived from the 7-day period encompassing the peak reaction. The mean scores for the acute reactions are presented. Tolerance doses, defined as the total doses resulting in one small area of moist desquamation in 50% of the animals, as calculated by probit analysis are 55.7 +- 0.7 Gy for the 4 x 2 Gy per day scheme and 67.3 +- 2.9 Gy for the 3 Gy per day scheme. It can be seen that, when increasing the total dose above the tolerance dose, the mean reaction to the 3 Gy per day regimen reaches a plateau (corresponding to 10 to 40% moist desquamation of the sole of the foot), while the reaction to the 4 x 2 Gy per day regimen increases to the maximum, i.e., moist desquamation of the entire foot. These differences can be attributed to differences in repair of sublethal damage and repopulation. (Auth.)

Stable radio frequency dissemination by simple hybrid frequency modulation scheme.

Science.gov (United States)

Yu, Longqiang; Wang, Rong; Lu, Lin; Zhu, Yong; Wu, Chuanxin; Zhang, Baofu; Wang, Peizhang

2014-09-15

In this Letter, we propose a fiber-based stable radio frequency transfer system by a hybrid frequency modulation scheme. Creatively, two radio frequency signals are combined and simultaneously transferred by only one laser diode. One frequency component is used to detect the phase fluctuation, and the other one is the derivative compensated signal providing a stable frequency for the remote end. A proper ratio of the frequencies of the components is well maintained by parameter m to avoid interference between them. Experimentally, a stable 200 MHz signal is transferred over 100 km optical fiber with the help of a 1 GHz detecting signal, and fractional instability of 2×10(-17) at 10(5) s is achieved.

The Theory of Exploitation as the Unequal Exchange of Labour

OpenAIRE

Veneziani, Roberto; Yoshihara, Naoki

2016-01-01

This paper analyses the normative and positive foundations of the theory of exploitation as the unequal exchange of labour (UEL). The key intuitions behind all of the main approaches to UEL exploitation are explicitly analysed as a series of formal claims in a general economic environment. It is then argued that these intuitions can be captured by one fundamental axiom - called Labour Exploitation - which defines the basic domain of all UEL exploitation forms and identifies the formal and the...

The theory of exploitation as the unequal exchange of labour

OpenAIRE

Veneziani, Roberto; Yoshihara, Naoki

2017-01-01

This paper analyses the normative and positive foundations of the theory of exploitation as the unequal exchange of labour (UEL). The key intuitions behind all of the main approaches to UEL exploitation are explicitly analysed as a series of formal claims in a general economic environment. It is then argued that these intuitions can be captured by one fundamental axiom - called Labour Exploitation - which defines the basic domain of all UEL exploitation forms and identifies the formal and the...

Fishery Development and Exploitation in South East Australia

Directory of Open Access Journals (Sweden)

Camilla Novaglio

2018-04-01

Full Text Available Understanding the full extent of past ecological changes in human-influenced marine systems is needed to inform present management policies, but is often hampered by the scarcity of information about exploitation practices and population status over the entire history of fishing. The history of commercial fishing in South East Australia is relatively recent and thus easier to document. Our aim is to reconstruct such history and to use this information to understand general patterns and consequences of fishing exploitation. Intense exploitation of marine resources arrived in South East Australia with European colonization in the early 1800s, and unregulated sealing, whaling and oyster dredging resulted in the first documented significant impact on local marine populations. Exploitation extended to demersal resources in 1915 when the trawl fishery developed. Between the early 1800s and the 1980s, some of the exploited stocks collapsed, but fishing moved further offshore and in deeper waters as technology improved and new resources became available or were discovered. This phase of fisheries expansion masked the unsustainable nature of some fishing industries, such as trawling and whaling, and postponed the need for management regulations. From the 1990s onward, an increasing awareness of the depleted nature of some fisheries led to the establishment of management strategies aiming at a more sustainable exploitation of target stocks and, from the mid-2000s onwards, management strategies were revised and improved to better address the effect of fishing on multiple components of marine ecosystems. This led to the recovery of some depleted populations and to increased habitat protection. The relatively short history of fishing exploitation and the small scale of the fishing industry in South East Australia played a significant role in limiting the magnitude of fishing impacts on local populations and helped to achieve recoveries when fisheries

Series expansion in fractional calculus and fractional differential equations

OpenAIRE

Li, Ming-Fan; Ren, Ji-Rong; Zhu, Tao

2009-01-01

Fractional calculus is the calculus of differentiation and integration of non-integer orders. In a recently paper (Annals of Physics 323 (2008) 2756-2778), the Fundamental Theorem of Fractional Calculus is highlighted. Based on this theorem, in this paper we introduce fractional series expansion method to fractional calculus. We define a kind of fractional Taylor series of an infinitely fractionally-differentiable function. Further, based on our definition we generalize hypergeometric functio...

Matroids and quantum-secret-sharing schemes

International Nuclear Information System (INIS)

Sarvepalli, Pradeep; Raussendorf, Robert

2010-01-01

A secret-sharing scheme is a cryptographic protocol to distribute a secret state in an encoded form among a group of players such that only authorized subsets of the players can reconstruct the secret. Classically, efficient secret-sharing schemes have been shown to be induced by matroids. Furthermore, access structures of such schemes can be characterized by an excluded minor relation. No such relations are known for quantum secret-sharing schemes. In this paper we take the first steps toward a matroidal characterization of quantum-secret-sharing schemes. In addition to providing a new perspective on quantum-secret-sharing schemes, this characterization has important benefits. While previous work has shown how to construct quantum-secret-sharing schemes for general access structures, these schemes are not claimed to be efficient. In this context the present results prove to be useful; they enable us to construct efficient quantum-secret-sharing schemes for many general access structures. More precisely, we show that an identically self-dual matroid that is representable over a finite field induces a pure-state quantum-secret-sharing scheme with information rate 1.

Numerical approximations of nonlinear fractional differential difference equations by using modified He-Laplace method

Directory of Open Access Journals (Sweden)

J. Prakash

2016-03-01

Full Text Available In this paper, a numerical algorithm based on a modified He-Laplace method (MHLM is proposed to solve space and time nonlinear fractional differential-difference equations (NFDDEs arising in physical phenomena such as wave phenomena in fluids, coupled nonlinear optical waveguides and nanotechnology fields. The modified He-Laplace method is a combined form of the fractional homotopy perturbation method and Laplace transforms method. The nonlinear terms can be easily decomposed by the use of He’s polynomials. This algorithm has been tested against time-fractional differential-difference equations such as the modified Lotka Volterra and discrete (modified KdV equations. The proposed scheme grants the solution in the form of a rapidly convergent series. Three examples have been employed to illustrate the preciseness and effectiveness of the proposed method. The achieved results expose that the MHLM is very accurate, efficient, simple and can be applied to other nonlinear FDDEs.

From Exploitation to Industry: Definitions, Risks, and Consequences of Domestic Sexual Exploitation and Sex Work Among Women and Girls.

Science.gov (United States)

Gerassi, Lara

In the last 15 years, terms such as prostitution, sex trafficking, sexual exploitation, modern-day slavery, and sex work have elicited much confusion and debate as to their definitions. Consequently several challenges have emerged for both law enforcement in the prosecution of criminals and practitioners in service provision. This article reviews the state of the literature with regard to domestic, sexual exploitation among women and girls in the United States and seeks to (1) provide definitions and describe the complexity of all terms relating to domestic sexual exploitation of women and girls in the United States, (2) explore available national prevalence data according to the definitions provided, and (3) review the evidence of mental health, social, and structural risk factors at the micro-, mezzo-, and macrolevels.

Fractional order nonlinear variable speed and current regulation of a permanent magnet synchronous generator wind turbine system

Directory of Open Access Journals (Sweden)

Anitha Karthikeyan

2018-03-01

Full Text Available In this paper we derived the fractional order model of the Permanent Magnet Synchronous Generator (PMSG from its integer model. The PMSG was employing a shaft sensor for the speed sensing and control. But this sensor would increase the hardware complexity as well as the cost of the system. Hence we have developed a Fractional order Nonlinear adaptive control method for speed and current tracking of the PMSG. The objective of an adaptive controller is to first define a virtual control state and force it to become a stabilizing function in accordance with a corresponding error dynamics. In order to study the Lyapunov exponents of the fractional order controller, we proposed a new method which would remove the complexity of finding the sign of the Lyapunov first derivative. The Fractional order control scheme is implemented in LabVIEW for simulation results. The simulation results indicated that the estimated rotor position and speed correspond to their actual values well. Keywords: Chaos suppression, Fractional order systems, Permanent magnet synchronous generator, Speed and current control, Lyapunov stability

Antioxidant and Antihypertensive Effects of a Chemically Defined Fraction of Syrah Red Wine on Spontaneously Hypertensive Rats.

Science.gov (United States)

Figueiredo, Eugênia Abrantes de; Alves, Naiane Ferraz Bandeira; Monteiro, Matheus Morais de Oliveira; Cavalcanti, Clenia de Oliveira; Silva, Tania Maria Sarmento da; Silva, Telma Maria Guedes da; Braga, Valdir de Andrade; Oliveira, Eduardo de Jesus

2017-06-03

A particularly phenolic-rich fraction extracted from red wine from the São Francisco valley (Northeastern Brazil) was chemically characterized and its hypotensive and antioxidant effects on spontaneously hypertensive rats were studied both in vitro and in vivo. The liquid-liquid pH dependent fractionation scheme afforded a fraction with high content of bioactive phenolics such as flavonols, flavonol glycosides, phenolic acids and anthocyanins, whose identities were confirmed by liquid chromatography coupled to mass spectrometry analysis. Pretreatment of spontaneously hypertensive rats with this wine fraction at doses of 50 and 100 mg/kg by gavage. for 15 days was able to decrease mean arterial pressure and heart rate as well as decrease serum lipid peroxidation. The fraction at concentrations of 0.01-1000 µg/mL induced concentration-dependent relaxation of isolated rat superior mesenteric artery rings pre-contracted with phenylephrine and this effect was not attenuated by endothelium removal. Our results demonstrate it is possible for phenolic constituents of red wine that are orally bioavailable to exert in vivo hypotensive and antioxidant effects on intact endothelial function.

Antioxidant and Antihypertensive Effects of a Chemically Defined Fraction of Syrah Red Wine on Spontaneously Hypertensive Rats

Directory of Open Access Journals (Sweden)

Eugênia Abrantes de Figueiredo

2017-06-01

Full Text Available A particularly phenolic-rich fraction extracted from red wine from the São Francisco valley (Northeastern Brazil was chemically characterized and its hypotensive and antioxidant effects on spontaneously hypertensive rats were studied both in vitro and in vivo. The liquid-liquid pH dependent fractionation scheme afforded a fraction with high content of bioactive phenolics such as flavonols, flavonol glycosides, phenolic acids and anthocyanins, whose identities were confirmed by liquid chromatography coupled to mass spectrometry analysis. Pretreatment of spontaneously hypertensive rats with this wine fraction at doses of 50 and 100 mg/kg by gavage. for 15 days was able to decrease mean arterial pressure and heart rate as well as decrease serum lipid peroxidation. The fraction at concentrations of 0.01–1000 µg/mL induced concentration-dependent relaxation of isolated rat superior mesenteric artery rings pre-contracted with phenylephrine and this effect was not attenuated by endothelium removal. Our results demonstrate it is possible for phenolic constituents of red wine that are orally bioavailable to exert in vivo hypotensive and antioxidant effects on intact endothelial function.

The ESA Geohazard Exploitation Platform

Science.gov (United States)

Bally, Philippe; Laur, Henri; Mathieu, Pierre-Philippe; Pinto, Salvatore

2015-04-01

Earthquakes represent one of the world's most significant hazards in terms both of loss of life and damages. In the first decade of the 21st century, earthquakes accounted for 60 percent of fatalities from natural disasters, according to the United Nations International Strategy for Disaster Reduction (UNISDR). To support mitigation activities designed to assess and reduce risks and improve response in emergency situations, satellite EO can be used to provide a broad range of geo-information services. This includes for instance crustal block boundary mapping to better characterize active faults, strain rate mapping to assess how rapidly faults are deforming, soil vulnerability mapping to help estimate how the soil is behaving in reaction to seismic phenomena, geo-information to assess the extent and intensity of the earthquake impact on man-made structures and formulate assumptions on the evolution of the seismic sequence, i.e. where local aftershocks or future main shocks (on nearby faults) are most likely to occur. In May 2012, the European Space Agency and the GEO Secretariat convened the International Forum on Satellite EO for Geohazards now known as the Santorini Conference. The event was the continuation of a series of international workshops such as those organized by the Geohazards Theme of the Integrated Global Observing Strategy Partnership. In Santorini the seismic community has set out a vision of the EO contribution to an operational global seismic risk program, which lead to the Geohazard Supersites and Natural Laboratories (GSNL) initiative. The initial contribution of ESA to suuport the GSNL was the first Supersites Exploitation Platform (SSEP) system in the framework of Grid Processing On Demand (GPOD), now followed by the Geohazard Exploitation Platform (GEP). In this presentation, we will describe the contribution of the GEP for exploiting satellite EO for geohazard risk assessment. It is supporting the GEO Supersites and has been further

Oil exploitation and the environmental Kuznets curve

International Nuclear Information System (INIS)

Esmaeili, Abdoulkarim; Abdollahzadeh, Negar

2009-01-01

This study refers to a panel estimation of an environmental Kuznets curve (EKC) for oil to determine the factors most affecting oil exploitation in 38 oil-producing countries during 1990-2000. Control variables such as oil reserves, oil price, population, political rights, and the Gini index were used to determine its contribution to the main EKC model. The empirical results fully support the existence of an EKC for oil exploitation. Furthermore, the result indicates that the proved oil reserves has a significant and positive role in oil production, but oil price and population do not significantly affect crude oil production. Also, increased freedoms and a better income distribution will reduce the rate of oil exploitation. Thus, policies aiming at enhancing democratic society and better income distribution would be more compatible with sustainability. (author)

Oil exploitation and the environmental Kuznets curve

Energy Technology Data Exchange (ETDEWEB)

Esmaeili, Abdoulkarim; Abdollahzadeh, Negar [Department of Agricultural Economics, College of Agriculture, Shiraz University, Shiraz, Fars (Iran)

2009-01-15

This study refers to a panel estimation of an environmental Kuznets curve (EKC) for oil to determine the factors most affecting oil exploitation in 38 oil-producing countries during 1990-2000. Control variables such as oil reserves, oil price, population, political rights, and the Gini index were used to determine its contribution to the main EKC model. The empirical results fully support the existence of an EKC for oil exploitation. Furthermore, the result indicates that the proved oil reserves has a significant and positive role in oil production, but oil price and population do not significantly affect crude oil production. Also, increased freedoms and a better income distribution will reduce the rate of oil exploitation. Thus, policies aiming at enhancing democratic society and better income distribution would be more compatible with sustainability. (author)

Fast and high-order numerical algorithms for the solution of multidimensional nonlinear fractional Ginzburg-Landau equation

Science.gov (United States)

Mohebbi, Akbar

2018-02-01

In this paper we propose two fast and accurate numerical methods for the solution of multidimensional space fractional Ginzburg-Landau equation (FGLE). In the presented methods, to avoid solving a nonlinear system of algebraic equations and to increase the accuracy and efficiency of method, we split the complex problem into simpler sub-problems using the split-step idea. For a homogeneous FGLE, we propose a method which has fourth-order of accuracy in time component and spectral accuracy in space variable and for nonhomogeneous one, we introduce another scheme based on the Crank-Nicolson approach which has second-order of accuracy in time variable. Due to using the Fourier spectral method for fractional Laplacian operator, the resulting schemes are fully diagonal and easy to code. Numerical results are reported in terms of accuracy, computational order and CPU time to demonstrate the accuracy and efficiency of the proposed methods and to compare the results with the analytical solutions. The results show that the present methods are accurate and require low CPU time. It is illustrated that the numerical results are in good agreement with the theoretical ones.

Scheme Program Documentation Tools

DEFF Research Database (Denmark)

Nørmark, Kurt

2004-01-01

are separate and intended for different documentation purposes they are related to each other in several ways. Both tools are based on XML languages for tool setup and for documentation authoring. In addition, both tools rely on the LAML framework which---in a systematic way---makes an XML language available...... as named functions in Scheme. Finally, the Scheme Elucidator is able to integrate SchemeDoc resources as part of an internal documentation resource....

Fractional governing equations of transient groundwater flow in confined aquifers with multi-fractional dimensions in fractional time

Directory of Open Access Journals (Sweden)

M. L. Kavvas

2017-10-01

Full Text Available Using fractional calculus, a dimensionally consistent governing equation of transient, saturated groundwater flow in fractional time in a multi-fractional confined aquifer is developed. First, a dimensionally consistent continuity equation for transient saturated groundwater flow in fractional time and in a multi-fractional, multidimensional confined aquifer is developed. For the equation of water flux within a multi-fractional multidimensional confined aquifer, a dimensionally consistent equation is also developed. The governing equation of transient saturated groundwater flow in a multi-fractional, multidimensional confined aquifer in fractional time is then obtained by combining the fractional continuity and water flux equations. To illustrate the capability of the proposed governing equation of groundwater flow in a confined aquifer, a numerical application of the fractional governing equation to a confined aquifer groundwater flow problem was also performed.

Fractional order sliding-mode control based on parameters auto-tuning for velocity control of permanent magnet synchronous motor.

Science.gov (United States)

Zhang, BiTao; Pi, YouGuo; Luo, Ying

2012-09-01

A fractional order sliding mode control (FROSMC) scheme based on parameters auto-tuning for the velocity control of permanent magnet synchronous motor (PMSM) is proposed in this paper. The control law of the proposed F(R)OSMC scheme is designed according to Lyapunov stability theorem. Based on the property of transferring energy with adjustable type in F(R)OSMC, this paper analyzes the chattering phenomenon in classic sliding mode control (SMC) is attenuated with F(R)OSMC system. A fuzzy logic inference scheme (FLIS) is utilized to obtain the gain of switching control. Simulations and experiments demonstrate that the proposed FROSMC not only achieve better control performance with smaller chatting than that with integer order sliding mode control, but also is robust to external load disturbance and parameter variations. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

A new time-space accounting scheme to predict stream water residence time and hydrograph source components at the watershed scale

Science.gov (United States)

Takahiro Sayama; Jeffrey J. McDonnell

2009-01-01

Hydrograph source components and stream water residence time are fundamental behavioral descriptors of watersheds but, as yet, are poorly represented in most rainfall-runoff models. We present a new time-space accounting scheme (T-SAS) to simulate the pre-event and event water fractions, mean residence time, and spatial source of streamflow at the watershed scale. We...

A Memory Efficient Network Encryption Scheme

Science.gov (United States)

El-Fotouh, Mohamed Abo; Diepold, Klaus

In this paper, we studied the two widely used encryption schemes in network applications. Shortcomings have been found in both schemes, as these schemes consume either more memory to gain high throughput or low memory with low throughput. The need has aroused for a scheme that has low memory requirements and in the same time possesses high speed, as the number of the internet users increases each day. We used the SSM model [1], to construct an encryption scheme based on the AES. The proposed scheme possesses high throughput together with low memory requirements.

Security option file - Exploitation (DOS-Expl)

International Nuclear Information System (INIS)

2016-01-01

This document aims at presenting functions performed by Cigeo during its exploitation phase, its main technical and security options which are envisaged with respect to different types of internal or external risks, and a first assessment of its impact on mankind and on the environment during its exploitation in normal operation as well as in incidental or accidental situations. A first volume addresses security principles, approach and management in relationship with the legal and regulatory framework. The second volume presents input data related to waste parcels and used for the installation sizing and operation, the main site characteristics, the main technical options regarding structures and equipment, and the main options regarding exploitation (parcel management, organisational and human aspects, and effluent management). The third volume describes how parcel are processed from their arrival to their setting in storage compartment, an inventory of internal and external risks, and a first assessment of consequences of scenarios on mankind and on the environment. The fourth volume presents options and operations which are envisaged regarding Cigeo closure, and inventory of associated risks

Modified Aggressive Packet Combining Scheme

International Nuclear Information System (INIS)

Bhunia, C.T.

2010-06-01

In this letter, a few schemes are presented to improve the performance of aggressive packet combining scheme (APC). To combat error in computer/data communication networks, ARQ (Automatic Repeat Request) techniques are used. Several modifications to improve the performance of ARQ are suggested by recent research and are found in literature. The important modifications are majority packet combining scheme (MjPC proposed by Wicker), packet combining scheme (PC proposed by Chakraborty), modified packet combining scheme (MPC proposed by Bhunia), and packet reversed packet combining (PRPC proposed by Bhunia) scheme. These modifications are appropriate for improving throughput of conventional ARQ protocols. Leung proposed an idea of APC for error control in wireless networks with the basic objective of error control in uplink wireless data network. We suggest a few modifications of APC to improve its performance in terms of higher throughput, lower delay and higher error correction capability. (author)

From Exploitation to Industry: Definitions, Risks, and Consequences of Domestic Sexual Exploitation and Sex Work Among Women and Girls

Science.gov (United States)

Gerassi, Lara

2015-01-01

In the last 15 years, terms such as prostitution, sex trafficking, sexual exploitation, modern-day slavery, and sex work have elicited much confusion and debate as to their definitions. Consequently several challenges have emerged for both law enforcement in the prosecution of criminals and practitioners in service provision. This article reviews the state of the literature with regard to domestic, sexual exploitation among women and girls in the United States and seeks to (1) provide definitions and describe the complexity of all terms relating to domestic sexual exploitation of women and girls in the United States, (2) explore available national prevalence data according to the definitions provided, and (3) review the evidence of mental health, social, and structural risk factors at the micro-, mezzo-, and macrolevels. PMID:26726289

A joint recovery scheme for carrier frequency offset and carrier phase noise using extended Kalman filter

Science.gov (United States)

Li, Linqian; Feng, Yiqiao; Zhang, Wenbo; Cui, Nan; Xu, Hengying; Tang, Xianfeng; Xi, Lixia; Zhang, Xiaoguang

2017-07-01

A joint carrier recovery scheme for polarization division multiplexing (PDM) coherent optical transmission system is proposed and demonstrated, in which the extended Kalman filter (EKF) is exploited to estimate and equalize the carrier frequency offset (CFO) and carrier phase noise (CPN) simultaneously. The proposed method is implemented and verified in the PDM-QPSK system and the PDM-16QAM system with the comparisons to conventional improved Mth-power (IMP) algorithm for CFO estimation, blind phase search (BPS) algorithm or Viterbi-Viterbi (V-V) algorithm for CPN recovery. It is demonstrated that the proposed scheme shows high CFO estimation accuracy, with absolute mean estimation error below 1.5 MHz. Meanwhile, the proposed method has the CFO tolerance of [±3 GHz] for PDM-QPSK system and [±0.9 GHz] for PDM-16QAM system. Compare with IMP/BPS and IMP/V-V, the proposed scheme can enhance the linewidth symbol duration product from 3 × 10-4 (IMP/BPS) and 2 × 10-4 (IMP/V-V) to 1 × 10-3 for PDM-QPSK, and from 1 × 10-4 (IMP/BPS) to 3 × 10-4 for PDM-16QAM, respectively, at the 1 dB optical signal-to-noise ratio (OSNR) penalty. The proposed Kalman filter also shows a fast convergence with only 100 symbols and much lower computational complexity.

Early Sexual Exploitation as an Influence in Prostitution.

Science.gov (United States)

Silbert, Mimi H.; Pines, Ayala M.

1983-01-01

Surveyed 200 female street prostitutes to determine whether they were sexually exploited during childhood. Results showed 60 percent of the subjects were sexually exploited. The few girls who discussed their abuse with others were met with shame and most often inaction. Only 10 percent were abused by strangers. (JAC)

Fractional governing equations of transient groundwater flow in confined aquifers with multi-fractional dimensions in fractional time

OpenAIRE

M. L. Kavvas; T. Tu; A. Ercan; J. Polsinelli

2017-01-01

Using fractional calculus, a dimensionally consistent governing equation of transient, saturated groundwater flow in fractional time in a multi-fractional confined aquifer is developed. First, a dimensionally consistent continuity equation for transient saturated groundwater flow in fractional time and in a multi-fractional, multidimensional confined aquifer is developed. For the equation of water flux within a multi-fractional multidimensional confined aquifer, a dimensionally...

The influence of fractionation on cell survival and premature differentiation after carbon ion irradiation

International Nuclear Information System (INIS)

Wang Jufang; Li Renming; Guo Chuanling; Fournier, C.; K-Weyrather, W.

2008-01-01

To investigate the influence of fractionation on cell survival and radiation induced premature differentiation as markers for early and late effects after X-rays and carbon irradiation. Normal human fibroblasts NHDF, AG1522B and WI-38 were irradiated with 250 kV X-rays, or 266 MeV/u, 195 MeV/u and 11 MeV/u carbon ions. Cytotoxicity was measured by a clonogenic survival assay or by determination of the differentiation pattern. Experiments with high-energy carbon ions show that fractionation induced repair effects are similar to photon irradiation. The relative biological effective (RBE) 10 values for clonogenic survival are 1.3 and 1.6 for irradiation in one or two fractions for NHDF cells and around 1.2 for AG1522B cells regardless of the fractionation scheme. The RBE for a doubling of post mitotic fibroblasts (PMF) in the population is 1 for both single and two fractionated irradiation of NHDF cells. Using 11 MeV/u carbon ions, no repair effect can be seen in WI-38 cells. The RBE 10 for clonogenic survival is 3.2 for single irradiation and 4.9 for two fractionated irradiations. The RBE for a doubling of PMF is 3.1 and 5.0 for single and two fractionated irradiations, respectively. For both cell lines the effects of high-energy carbon ions representing the irradiation of the skin and the normal tissue in the entrance channel are similar to the effects of X-rays. The fractionation effects are maintained. For the lower energy, which is representative for the irradiation of the tumor region, RBE is enhanced for clonogenic survival as well as for premature terminal differentiation. Fractionation effects are not detectable. Consequently, the therapeutic ratio is significantly enhanced by fractionated irradiation with carbon ions. (author)

Dissemination and Exploitation: Project Goals beyond Science

Science.gov (United States)

Hamann, Kristin; Reitz, Anja

2017-04-01

Dissemination and Exploitation are essential parts of public funded projects. In Horizon 2020 a plan for the exploitation and dissemination of results (PEDR) is a requirement. The plan should contain a clear vision on the objectives of the project in relation to actions for dissemination and potential exploitation of the project results. The actions follow the basic idea to spread the knowledge and results gathered within the project and face the challenge of how to bring the results into potentially relevant policy circle and how they impact the market. The plan follows the purpose to assess the impact of the project and to address various target groups who are interested in the project results. Simply put, dissemination concentrates on the transfer of knowledge and exploitation on the commercialization of the project. Beyond the question of the measurability of project`s impact, strategies within science marketing can serve purposes beyond internal and external communication. Accordingly, project managers are facing the challenge to implement a dissemination and exploitation strategy that ideally supports the identification of all partners with the project and matches the current discourse of the project`s content within the society, politics and economy. A consolidated plan might unite all projects partners under a central idea and supports the identification with the project beyond the individual research questions. Which applications, strategies and methods can be used to bring forward a PEDR that accompanies a project successfully and allows a comprehensive assessment of the project afterwards? Which hurdles might project managers experience in the dissemination process and which tasks should be fulfilled by the project manager?

Significance of fractionation regimens in radiation and combined hyperthermia using a murine fibrosarcoma

International Nuclear Information System (INIS)

Hahn, E.W.; Alfieri, A.A.; Kim, J.H.

1978-01-01

The significance of time--dose ralationships in the use of local tumor hyperthermia (LTH) when combined with radiation (RAD) was studied in a murine fibrosarcoma. RAD, either alone or combined with LTH, was delivered in four equal fractions (total doses, 1.8 to 4.2 krad) separated by 1 to 4 days. LTH (43.1 C +- .05 C for 15 minutes, water bath) was applied immediately after RAD. In this tumor system, RAD was most effective when delivered every 2nd or 3rd day, by a factor of 1.25 over the response achieved when the four fractions were delivered every 1 or 4 days. At all levels studied, RAD + LTH produced a superior tumor response compared to RAD alone. The ratio of the RAD + LTH/RAD doses to achieve an isobiological response ranged from 1.7 to 2.5. Most significant was the finding that the RAD + LTH treatment response was independent of the fractionation scheme used and more dependent on the total RAD dose delivered

Solution of Fractional Order System of Bagley-Torvik Equation Using Evolutionary Computational Intelligence

Directory of Open Access Journals (Sweden)

Muhammad Asif Zahoor Raja

2011-01-01

Full Text Available A stochastic technique has been developed for the solution of fractional order system represented by Bagley-Torvik equation. The mathematical model of the equation was developed with the help of feed-forward artificial neural networks. The training of the networks was made with evolutionary computational intelligence based on genetic algorithm hybrid with pattern search technique. Designed scheme was successfully applied to different forms of the equation. Results are compared with standard approximate analytic, stochastic numerical solvers and exact solutions.

Bonus schemes and trading activity

NARCIS (Netherlands)

Pikulina, E.S.; Renneboog, L.D.R.; ter Horst, J.R.; Tobler, P.N.

2014-01-01

Little is known about how different bonus schemes affect traders' propensity to trade and which bonus schemes improve traders' performance. We study the effects of linear versus threshold bonus schemes on traders' behavior. Traders buy and sell shares in an experimental stock market on the basis of

[Ecotourism exploitation model in Bita Lake Natural Reserve of Yunnan].

Science.gov (United States)

Yang, G; Wang, Y; Zhong, L

2000-12-01

Bita lake provincial natural reserve is located in Shangri-La region of North-western Yunnan, and was set as a demonstrating area for ecotourism exploitation in 1998. After a year's exploitation construction and half a year's operation as a branch of the 99' Kunming International Horticulture Exposition to accept tourists, it was proved that the ecotourism demonstrating area attained four integrated functions of ecotourism, i.e., tourism, protection, poverty clearing and environment education. Five exploitation and management models including function zoned exploitation model, featured tourism communication model signs system designing model, local Tibetan family reception model and environmental monitoring model, were also successful, which were demonstrated and spreaded to the whole province. Bita lake provincial natural reserve could be a good sample for the ecotourism exploitation natural reserves of the whole country.

Catalog of gamma-rays unplaced in radioactive decay schemes

International Nuclear Information System (INIS)

Narita, Tsutomu; Kitao, Kensuke.

1991-03-01

A catalog is made for gamma-rays emitted in decay of radioactive nuclides but not placed in their decay schemes. It consists of two tables. In Table 1, the number of these unplaced gamma-ray components by a nuclide is given together with the fraction of total intensity of these gamma-rays to that of all observed gamma-rays. In Table 2, the unplaced gamma-rays are arranged in order of increasing energy. Each line of this table contains the gamma-ray energy, intensity, nuclide identification, and energies and intensities of the most prominent gamma-rays from the decay of the radionuclides. This catalog is a compilation from Evaluated Nuclear Structure Data File (ENSDF) maintained by National Nuclear Data Center at Brookhaven National Laboratory, of at February 1990. (author)

EVALUATION OF THERMAL EFFICIENCY OF THE TECHNOLOGICAL SCHEME OF APPLE CHIPS AND DRIED FRUITS PRODUCTION

Directory of Open Access Journals (Sweden)

G. V. Kalashnikov

2014-01-01

Full Text Available The estimation of thermodynamic perfection of separate technological processes is executed at heat-moisture of handling of fruit and a line of manufacture of fruit apple chips and dried fruits. The technological scheme of a line of processing of fruits and manufactures of fruit chips on the basis of convection and the microwave-dryings suggested resource-saving. The technique is made and results of calculation of thermal expenses for various schemes of manufacture of apple chips are resulted. For the offered scheme material, thermal and power streams on the basis of balance parities of technological processes are certain. The comparative thermal production efficiency of apple chips for a base foreign variant and the offered technological scheme with the closed cycle of use of the heat-carrier and the combined convection-microwave-drying is shown. In this paper we define the thermal and energy flows for the processes of convective drying, pre-microwave drying, hydrothermal treatment and final microwave drying plant material, which are one of the main stages of the production of all kinds of fruit and vegetable concentrates, including fruit apple chips. Resource-saving ways moisture-heat of handling (hydration, blanching, drying, etc. produce raw materials in the production of food concentrates suggested a reduced water flow with a high degree of use of its potential power and microwave sources. To assess the thermal efficiency of the various processes and production schemes used as indicators of thermal efficiency and proposed value of specific heat (kJ / kg given mass productivity per unit of feedstock and translational moisture. The values of the mass fraction of the heat of material flows for the base and the proposed resource-saving production scheme fruit chips, for example, apple, based on a combination of convection-microwave drying each control surface.

Self-seeding scheme for the soft X-ray line at the European XFEL

International Nuclear Information System (INIS)

Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

2012-02-01

This paper discusses the potential for enhancing the capabilities of the European FEL in the soft X-ray regime. A high longitudinal coherence will be the key to such performance upgrade. In order to reach this goal we study a very compact soft X-ray self-seeding scheme originally designed at SLAC. The scheme is based on a grating monochromator, and can be straightforwardly installed in the SASE3 undulator beamline at the European XFEL. For the European XFEL fully-coherent soft X-ray pulses are particularly valuable since they naturally support the extraction of more FEL power than at saturation by exploiting tapering in the tunable-gap SASE3 undulator. Tapering consists of a stepwise change of the undulator gap from segment to segment. Based on start-to-end simulations we show that soft X-ray FEL power reaches about 800 GW, that is about an order of magnitude higher than the SASE level at saturation (100 GW). The self-seeding setup studied in this work is extremely compact (about 5 m long), and cost-effective. This last characteristic may justify to consider it as a possible addition to the European XFEL capabilities from the very beginning of the operation phase. (orig.)

Self-seeding scheme for the soft X-ray line at the European XFEL

Energy Technology Data Exchange (ETDEWEB)

Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2012-02-15

This paper discusses the potential for enhancing the capabilities of the European FEL in the soft X-ray regime. A high longitudinal coherence will be the key to such performance upgrade. In order to reach this goal we study a very compact soft X-ray self-seeding scheme originally designed at SLAC. The scheme is based on a grating monochromator, and can be straightforwardly installed in the SASE3 undulator beamline at the European XFEL. For the European XFEL fully-coherent soft X-ray pulses are particularly valuable since they naturally support the extraction of more FEL power than at saturation by exploiting tapering in the tunable-gap SASE3 undulator. Tapering consists of a stepwise change of the undulator gap from segment to segment. Based on start-to-end simulations we show that soft X-ray FEL power reaches about 800 GW, that is about an order of magnitude higher than the SASE level at saturation (100 GW). The self-seeding setup studied in this work is extremely compact (about 5 m long), and cost-effective. This last characteristic may justify to consider it as a possible addition to the European XFEL capabilities from the very beginning of the operation phase. (orig.)

Innovative ICF scheme-impact fast ignition

International Nuclear Information System (INIS)