WorldWideScience

Sample records for dwell time distribution

  1. Modelling of Attentional Dwell Time

    DEFF Research Database (Denmark)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus

    2009-01-01

    . This confinement of attentional resources leads to the impairment in identifying the second target. With the model, we are able to produce close fits to data from the traditional two target dwell time paradigm. A dwell-time experiment with three targets has also been carried out for individual subjects...... and the model has been extended to fit these data....

  2. Dwell-Time Distribution, Long Pausing and Arrest of Single-Ribosome Translation through the mRNA Duplex.

    Science.gov (United States)

    Xie, Ping

    2015-10-09

    Proteins in the cell are synthesized by a ribosome translating the genetic information encoded on the single-stranded messenger RNA (mRNA). It has been shown that the ribosome can also translate through the duplex region of the mRNA by unwinding the duplex. Here, based on our proposed model of the ribosome translation through the mRNA duplex we study theoretically the distribution of dwell times of the ribosome translation through the mRNA duplex under the effect of a pulling force externally applied to the ends of the mRNA to unzip the duplex. We provide quantitative explanations of the available single molecule experimental data on the distribution of dwell times with both short and long durations, on rescuing of the long paused ribosomes by raising the pulling force to unzip the duplex, on translational arrests induced by the mRNA duplex and Shine-Dalgarno(SD)-like sequence in the mRNA. The functional consequences of the pauses or arrests caused by the mRNA duplex and the SD sequence are discussed and compared with those obtained from other types of pausing, such as those induced by "hungry" codons or interactions of specific sequences in the nascent chain with the ribosomal exit tunnel.

  3. Hold it! memory affects attentional dwell time

    OpenAIRE

    Parks, Emily L.; Hopfinger, Joseph B.

    2008-01-01

    The allocation of attention, including the initial orienting and the subsequent dwell time, is affected by several bottom-up and top-down factors. How item memory affects these processes, however, remains unclear. Here, we investigated whether item memory affects attentional dwell time by using a modified version of the attentional blink (AB) paradigm. Across four experiments, our results revealed that the AB was significantly affected by memory status (novel vs. old), but critically, this ef...

  4. 24 CFR 9.153 - Distribution of accessible dwelling units.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Distribution of accessible dwelling units. 9.153 Section 9.153 Housing and Urban Development Office of the Secretary, Department of Housing... dwelling units. Accessible dwelling units required by § 9.152 shall, to the maximum extent feasible, be...

  5. 24 CFR 8.26 - Distribution of accessible dwelling units.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Distribution of accessible dwelling units. 8.26 Section 8.26 Housing and Urban Development Office of the Secretary, Department of Housing... accessible dwelling units. Accessible dwelling units required by § 8.22, 8.23, 8.24 or 8.25 shall, to the...

  6. Yet one more dwell time algorithm

    Science.gov (United States)

    Haberl, Alexander; Rascher, Rolf

    2017-06-01

    The current demand of even more powerful and efficient microprocessors, for e.g. deep learning, has led to an ongoing trend of reducing the feature size of the integrated circuits. These processors are patterned with EUV-lithography which enables 7 nm chips [1]. To produce mirrors which satisfy the needed requirements is a challenging task. Not only increasing requirements on the imaging properties, but also new lens shapes, such as aspheres or lenses with free-form surfaces, require innovative production processes. However, these lenses need new deterministic sub-aperture polishing methods that have been established in the past few years. These polishing methods are characterized, by an empirically determined TIF and local stock removal. Such a deterministic polishing method is ion-beam-figuring (IBF). The beam profile of an ion beam is adjusted to a nearly ideal Gaussian shape by various parameters. With the known removal function, a dwell time profile can be generated for each measured error profile. Such a profile is always generated pixel-accurately to the predetermined error profile, with the aim always of minimizing the existing surface structures up to the cut-off frequency of the tool used [2]. The processing success of a correction-polishing run depends decisively on the accuracy of the previously computed dwell-time profile. So the used algorithm to calculate the dwell time has to accurately reflect the reality. But furthermore the machine operator should have no influence on the dwell-time calculation. Conclusively there mustn't be any parameters which have an influence on the calculation result. And lastly it should take a minimum of machining time to get a minimum of remaining error structures. Unfortunately current dwell time algorithm calculations are divergent, user-dependent, tending to create high processing times and need several parameters to bet set. This paper describes an, realistic, convergent and user independent dwell time algorithm. The

  7. Train Dwell Time Models for Rail Passenger Service

    Directory of Open Access Journals (Sweden)

    San Hor Peay

    2016-01-01

    Full Text Available In recent years, more studies had been conducted about train dwell time as it is a key parameter of rail system performance and reliability. This paper draws an overview of train dwell time models for rail passenger service from various continents, namely Asia, North America, Europe and Australia. The factors affecting train dwell time are identified and analysed across some rail network operators. The dwell time models developed by various researches are also discussed and reviewed. Finally, the contributions from the outcomes of these models are briefly addressed. In conclusion, this paper suggests that there is a need to further study the factors with strong influence upon dwell time to improve the quality of the train services.

  8. Distribution and status of the desert-dwelling giraffe ( Giraffa ...

    African Journals Online (AJOL)

    The population density and distribution of desert dwelling giraffes was estimated in three study areas in the Hoanib River catchment, northwestern Namibia. Giraffe population densities (0.01 giraffe/km2) were equal to the lowest recorded in Africa with population numbers fluctuating over past decades. Sex ratios, herd sizes ...

  9. The effect of masking in the attentional dwell time paradigm

    DEFF Research Database (Denmark)

    Petersen, Anders

    2009-01-01

    , 1994). In most studies of attentional dwell time, two masked targets have been used. Moore et al. (1996) have criticised the masking of the first target when measuring the attentional dwell time, finding a shorter attentional dwell time when the first mask was omitted. In the presented work, the effect...... of the first mask is further investigated by including a condition where the first mask is presented without a target. The results from individual subjects show that the findings of Moore et al. can be replicated. The results also suggest that presenting the first mask without a target is enough to produce...... an impairment of the second target. Hence, the attentional dwell time may be a combined effect arising from attending to both the first target and its mask....

  10. Spin-dependent dwell time through ferromagnetic graphene barrier

    International Nuclear Information System (INIS)

    Sattari, F.

    2014-01-01

    We investigated the dwell time of electrons tunneling through a ferromagnetic (FM) graphene barrier. The results show that the spin polarization can be efficiently controlled by the barrier width, barrier height, and the incident electron energy. Furthermore, it is found that electrons with different spin orientations will spend different times through the barrier. The difference of the dwell time between spin-up and spin-down electrons arises from the exchange splitting, which is induced by the FM strip. Study results indicate that a ferromagnetic graphene barrier can cause a nature spin filter mechanism in the time domain

  11. Dwell time adjustment for focused ion beam machining

    International Nuclear Information System (INIS)

    Taniguchi, Jun; Satake, Shin-ichi; Oosumi, Takaki; Fukushige, Akihisa; Kogo, Yasuo

    2013-01-01

    Focused ion beam (FIB) machining is potentially useful for micro/nano fabrication of hard brittle materials, because the removal method involves physical sputtering. Usually, micro/nano scale patterning of hard brittle materials is very difficult to achieve by mechanical polishing or dry etching. Furthermore, in most reported examples, FIB machining has been applied to silicon substrates in a limited range of shapes. Therefore, a versatile method for FIB machining is required. We previously established the dwell time adjustment for mechanical polishing. The dwell time adjustment is calculated by using a convolution model derived from Preston’s hypothesis. More specifically, the target removal shape is a convolution of the unit removal shape, and the dwell time is calculated by means of one of four algorithms. We investigate these algorithms for dwell time adjustment in FIB machining, and we found that a combination a fast Fourier transform calculation technique and a constraint-type calculation is suitable. By applying this algorithm, we succeeded in machining a spherical lens shape with a diameter of 2.93 μm and a depth of 203 nm in a glassy carbon substrate by means of FIB with dwell time adjustment

  12. Dwell time considerations for large area cold plasma decontamination

    Science.gov (United States)

    Konesky, Gregory

    2009-05-01

    Atmospheric discharge cold plasmas have been shown to be effective in the reduction of pathogenic bacteria and spores and in the decontamination of simulated chemical warfare agents, without the generation of toxic or harmful by-products. Cold plasmas may also be useful in assisting cleanup of radiological "dirty bombs." For practical applications in realistic scenarios, the plasma applicator must have both a large area of coverage, and a reasonably short dwell time. However, the literature contains a wide range of reported dwell times, from a few seconds to several minutes, needed to achieve a given level of reduction. This is largely due to different experimental conditions, and especially, different methods of generating the decontaminating plasma. We consider these different approaches and attempt to draw equivalencies among them, and use this to develop requirements for a practical, field-deployable plasma decontamination system. A plasma applicator with 12 square inches area and integral high voltage, high frequency generator is described.

  13. The effect of tubing dwell time on insulin adsorption during intravenous insulin infusions.

    Science.gov (United States)

    Thompson, Cecilia D; Vital-Carona, Jessica; Faustino, E Vincent S

    2012-10-01

    Insulin adsorbs to plastic tubing, which decreases the concentration of an insulin solution delivered from an intravenous infusion set. Dwelling insulin within tubing before starting the infusion decreases adsorption but delays treatment initiation and wastes time in infusion preparation. The lack of data on dwell time effects results in wide variability in practice. We aim to determine the effect of dwell time on insulin concentration from intravenous infusion tubing. In this in vitro study, we used insulin solutions with concentrations of 0.1 unit/mL, 1 unit/mL, and 10 units/mL. Each solution dwelled in intravenous infusion sets for 0, 15, 30, or 60 min. After the dwell, we measured insulin concentrations from the solution bags and tubing. We repeated each insulin concentration-dwell time combination five times. Comparisons were performed using analyses of variance. For each of the three insulin concentrations, the mean insulin concentrations from the tubing were not significantly different between dwell times. Duration of dwell time did not affect insulin adsorption in polypropylene intravenous infusion sets. We recommend that following a 20-mL flush, insulin infusions can be started without any dwell time. Removal of dwell times may improve clinical practice by minimizing preparation time and will allow faster initiation of insulin infusion therapy.

  14. A phantom for verification of dwell position and time of a high dose rate brachytherapy source

    International Nuclear Information System (INIS)

    Madebo, M.; Kron, T.; Pillainayagam, J.; Franich, R.

    2012-01-01

    Accuracy of dwell position and reproducibility of dwell time are critical in high dose rate (HDR) brachytherapy. A phantom was designed to verify dwell position and dwell time reproducibility for an Ir-192 HDR stepping source using Computed Radiography (CR). The central part of the phantom, incorporating thin alternating strips of lead and acrylic, was used to measure dwell positions. The outer part of the phantom features recesses containing different absorber materials (lead, aluminium, acrylic and polystyrene foam), and was used for determining reproducibility of dwell times. Dwell position errors of <1 mm were easily detectable using the phantom. The effect of bending a transfer tube was studied with this phantom and no change of clinical significance was observed when varying the curvature of the transfer tube in typical clinical scenarios. Changes of dwell time as low as 0.1 s, the minimum dwell time of the treatment unit, could be detected by choosing dwell times over the four materials that produce identical exposure at the CR detector.

  15. Contamination of dwellings by particulate matter: ingress and distribution within the dwelling

    International Nuclear Information System (INIS)

    Cannell, R.J.; Goddard, A.J.H.; ApSimon, H.M.

    1987-01-01

    A newly developed system for rapid, non-invasive measurements of deposited fluorescent tracer materials over extended surface areas has been used to gather information on the rate at which these materials would be introduced into a dwelling from the exterior by the occupants' footwear. Some additional information on the rate at which redistribution would occur and the potential for decontamination by normal household equipment has also been obtained. The limitations of using tracers to acquire such data are recognised but few experimental alternatives exist. Further work is planned to extend the range of particle sizes used in the continuing laboratory studies before a more realistic simulation is undertaken in test houses. (author)

  16. Estimation of train dwell time at short stops based on track occupation event data

    NARCIS (Netherlands)

    Li, D.; Daamen, W.; Goverde, R.M.P.

    2015-01-01

    Train dwell time is one of the most unpredictable components of railway operations mainly due to the varying volumes of alighting and boarding passengers. For reliable estimations of train running times and route conflicts on main lines it is however necessary to obtain accurate estimations of dwell

  17. Dwell time-based stabilisation of switched delay systems using free-weighting matrices

    Science.gov (United States)

    Koru, Ahmet Taha; Delibaşı, Akın; Özbay, Hitay

    2018-01-01

    In this paper, we present a quasi-convex optimisation method to minimise an upper bound of the dwell time for stability of switched delay systems. Piecewise Lyapunov-Krasovskii functionals are introduced and the upper bound for the derivative of Lyapunov functionals is estimated by free-weighting matrices method to investigate non-switching stability of each candidate subsystems. Then, a sufficient condition for the dwell time is derived to guarantee the asymptotic stability of the switched delay system. Once these conditions are represented by a set of linear matrix inequalities , dwell time optimisation problem can be formulated as a standard quasi-convex optimisation problem. Numerical examples are given to illustrate the improvements over previously obtained dwell time bounds. Using the results obtained in the stability case, we present a nonlinear minimisation algorithm to synthesise the dwell time minimiser controllers. The algorithm solves the problem with successive linearisation of nonlinear conditions.

  18. Using Variable Dwell Time to Accelerate Gaze-based Web Browsing with Two-step Selection

    OpenAIRE

    Chen, Zhaokang; Shi, Bertram E.

    2017-01-01

    In order to avoid the "Midas Touch" problem, gaze-based interfaces for selection often introduce a dwell time: a fixed amount of time the user must fixate upon an object before it is selected. Past interfaces have used a uniform dwell time across all objects. Here, we propose an algorithm for adjusting the dwell times of different objects based on the inferred probability that the user intends to select them. In particular, we introduce a probabilistic model of natural gaze behavior while sur...

  19. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    International Nuclear Information System (INIS)

    Balvert, Marleen; Gorissen, Bram L; Den Hertog, Dick; Hoffmann, Aswin L

    2015-01-01

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell time modulation restriction (DTMR) that limits dwell time differences between neighboring dwell positions has been suggested to eliminate this problem. DTMRs may additionally reduce the sensitivity for uncertainties in dwell positions that inevitably result from catheter reconstruction errors and afterloader source positioning inaccuracies. This study quantifies the reduction of high-dose subvolumes and the robustness against these uncertainties by applying a DTMR to template-based prostate HDR brachytherapy implants. Three different DTMRs were consecutively applied to a linear dose-based penalty model (LD) and a dose-volume based model (LDV), both obtained from literature. The models were solved with DTMR levels ranging from no restriction to uniform dwell times within catheters in discrete steps. Uncertainties were simulated on clinical cases using in-house developed software, and dose-volume metrics were calculated in each simulation. For the assessment of high-dose subvolumes, the dose homogeneity index (DHI) and the contiguous dose volume histogram were analysed. Robustness was measured by the improvement of the lowest D 90% of the planning target volume (PTV) observed in the simulations. For (LD), a DTMR yields an increase in DHI of approximately 30% and reduces the size of the largest high-dose volume by 2–5 cc. However, this comes at a cost of a reduction in D 90% of the PTV of 10%, which often implies that it drops below the desired minimum of 100%. For (LDV), none of the DTMRs were able to improve high-dose volume measures. DTMRs were not capable of improving robustness of PTV D 90% against uncertainty in dwell positions for both models. (paper)

  20. Evaluating Distributed Timing Constraints

    DEFF Research Database (Denmark)

    Kristensen, C.H.; Drejer, N.

    1994-01-01

    In this paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems.......In this paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems....

  1. A Fuzzy Logic-Based Approach for Estimation of Dwelling Times of Panama Metro Stations

    Directory of Open Access Journals (Sweden)

    Aranzazu Berbey Alvarez

    2015-04-01

    Full Text Available Passenger flow modeling and station dwelling time estimation are significant elements for railway mass transit planning, but system operators usually have limited information to model the passenger flow. In this paper, an artificial-intelligence technique known as fuzzy logic is applied for the estimation of the elements of the origin-destination matrix and the dwelling time of stations in a railway transport system. The fuzzy inference engine used in the algorithm is based in the principle of maximum entropy. The approach considers passengers’ preferences to assign a level of congestion in each car of the train in function of the properties of the station platforms. This approach is implemented to estimate the passenger flow and dwelling times of the recently opened Line 1 of the Panama Metro. The dwelling times obtained from the simulation are compared to real measurements to validate the approach.

  2. Dwell time dependent morphological transition and sputtering yield of ion sputtered Sn

    International Nuclear Information System (INIS)

    Qian, H X; Zeng, X R; Zhou, W

    2010-01-01

    Self-organized nano-scale patterns may appear on a wide variety of materials irradiated with an ion beam. Good manipulation of these structures is important for application in nanostructure fabrication. In this paper, dwell time has been demonstrated to be able to control the ripple formation and sputtering yield on Sn surface. Ripples with a wavelength of 1.7 μm were observed for a dwell time in the range 3-20 μs, whereas much finer ripples with a wavelength of 540 nm and a different orientation were observed for a shorter dwell time in the range 0.1-2 μs. The sputtering yield increases with dwell time significantly. The results provide a new basis for further steps in the theoretical description of morphology evolution during ion beam sputtering.

  3. Influences of dwell time and cursor control on the performance in gaze driven typing

    OpenAIRE

    Helmert, Jens R.; Pannasch, Sebastian; Velichkovsky, Boris M.

    2008-01-01

    In gaze controlled computer interfaces the dwell time is often used as selection criterion. But this solution comes along with several problems, especially in the temporal domain: Eye movement studies on scene perception could demonstrate that fixations of different durations serve different purposes and should therefore be differentiated. The use of dwell time for selection implies the need to distinguish intentional selections from merely per-ceptual processes, described as the Midas touch ...

  4. Impact of Interlayer Dwell Time on Microstructure and Mechanical Properties of Nickel and Titanium Alloys

    Science.gov (United States)

    Foster, B. K.; Beese, A. M.; Keist, J. S.; McHale, E. T.; Palmer, T. A.

    2017-09-01

    Path planning in additive manufacturing (AM) processes has an impact on the thermal histories experienced at discrete locations in simple and complex AM structures. One component of path planning in directed energy deposition is the time required for the laser or heat source to return to a given location to add another layer of material. As structures become larger and more complex, the length of this interlayer dwell time can significantly impact the resulting thermal histories. The impact of varying dwell times between 0 and 40 seconds on the microstructural and mechanical properties of Inconel® 625 and Ti-6Al-4V builds has been characterized. Even though these materials display different microstructures and solid-state phase transformations, the addition of an interlayer dwell generally led to a finer microstructure in both materials that impacted the resulting mechanical properties. With the addition of interlayer dwell times up to 40 seconds in the Inconel® 625 builds, finer secondary dendrite arm spacing values, produced by changes in the thermal history, correspond to increased yield and tensile strengths. These mechanical properties did not appear to change significantly, however, for dwell times greater than 20 seconds in the Inconel® 625 builds, indicating that longer dwell times have a minimal impact. The addition of interlayer dwell times in Ti-6Al-4V builds resulted in a slight decrease in the measured alpha lath widths and a much more noticeable decrease in the width of prior beta grains. In addition, the yield and tensile values continued to increase, nearly reaching the values observed in the rolled plate substrate material with dwell times up to 40 seconds.

  5. Association of unipedal standing time and bone mineral density in community-dwelling Japanese women.

    Science.gov (United States)

    Sakai, A; Toba, N; Takeda, M; Suzuki, M; Abe, Y; Aoyagi, K; Nakamura, T

    2009-05-01

    Bone mineral density (BMD) and physical performance of the lower extremities decrease with age. In community-dwelling Japanese women, unipedal standing time, timed up and go test, and age are associated with BMD while in women aged 70 years and over, unipedal standing time is associated with BMD. The aim of this study was to clarify whether unipedal standing time is significantly associated with BMD in community-dwelling women. The subjects were 90 community-dwelling Japanese women aged 54.7 years. BMD of the second metacarpal bone was measured by computed X-ray densitometry. We measured unipedal standing time as well as timed up and go test to assess physical performance of the lower extremities. Unipedal standing time decreased with increased age. Timed up and go test significantly correlated with age. Low BMD was significantly associated with old age, short unipedal standing time, and long timed up and go test. Stepwise regression analysis revealed that age, unipedal standing time, and timed up and go test were significant factors associated with BMD. In 21 participants aged 70 years and over, body weight and unipedal standing time, but not age, were significantly associated with BMD. BMD and physical performance of the lower extremities decrease with older age. Unipedal standing time, timed up and go test, and age are associated with BMD in community-dwelling Japanese women. In women aged 70 years and over, unipedal standing time is significantly associated with BMD.

  6. Larmor precession and dwell time of a relativistic particle scattered by a rectangular quantum well

    CERN Document Server

    Li, Z J; Liang, J J; Liang, J Q

    2003-01-01

    The Larmor precession of a relativistic neutral spin particle in a uniform constant magnetic field confined to the region of a one-dimensional rectangular potential well is investigated. The spin precession serves as a clock to measure the time spent by a quantum particle dwelling at a potential well. With the help of a general spin coherent state it is explicitly shown that the spin precession time is equal to the dwell time in the first-order approximation of the infinitesimal field limit. The comparison of the time in a potential well with that in free space shows apparent superluminality.

  7. Radon levels in dwellings in chalk terrain. Development and analysis of distributional and causal models

    International Nuclear Information System (INIS)

    Killip, Ian Richmond

    2002-01-01

    This thesis investigates the range, distribution and causes of high radon levels in dwellings in the Brighton area of Southeast England. Indoor radon levels were measured in more than 1000 homes. The results show that high radon levels can arise in an area previously considered to offer low radon potential from local geological sources. Climate and building-related factors were found to affect significantly the radon levels in dwellings. Multiple regression was used to determine the influence of the various factors on indoor radon levels and an empirical model develop to predict indoor radon levels. The radon hazard, independent of building-related effects, was determined for each surveyed location by adjusting the radon measurement to that expected on the ground floor of a 'model' dwelling. This standardised set of radon levels was entered into a geographical information system (GIS) and related to surface geology. The geometric mean radon level for each lithological unit was plotted to produce a radon hazard map for the area. The highest radon levels were found to be associated with the youngest Chalk Formations, particularly where they meet overlying Tertiary deposits, and with Clay-with-Flints Quaternary deposits in the area. The results were also converted to the radon activity equivalent to that expected from the NRPB's standard dual-detector dwelling survey method and analysed by lognormal modelling to estimate the proportion of dwellings likely to exceed the UK Action Level of 200 Bq/m 3 for each lithological unit. The likely percentages of dwellings affected by radon thus obtained were mapped to lithological boundaries to produce a radon potential map. The radon hazard map and the empirical radon model facilitate the prediction of radon levels in dwellings of comparable construction and above similar geology and should further the understanding of the behaviour of radon gas in buildings to allow indoor radon concentrations to be controlled. The radon

  8. General relation between the group delay and dwell time in multicomponent electron systems

    Science.gov (United States)

    Zhai, Feng; Lu, Junqiang

    2016-10-01

    For multicomponent electron scattering states, we derive a general relation between the Wigner group delay and the Bohmian dwell time. It is found that the definition of group delay should account for the phase of the spinor wave functions of propagating modes. The difference between the group delay and dwell time comes from both the interference delay and the decaying modes. For barrier tunneling of helical electrons on a surface of topological insulators, our calculations including the trigonal-warping term show that the decaying modes can contribute greatly to the group delay. The derived relation between the group delay and the dwell time is helpful to unify the two definitions of tunneling time in a quite general situation.

  9. An ELM-Based Approach for Estimating Train Dwell Time in Urban Rail Traffic

    Directory of Open Access Journals (Sweden)

    Wen-jun Chu

    2015-01-01

    Full Text Available Dwell time estimation plays an important role in the operation of urban rail system. On this specific problem, a range of models based on either polynomial regression or microsimulation have been proposed. However, the generalization performance of polynomial regression models is limited and the accuracy of existing microsimulation models is unstable. In this paper, a new dwell time estimation model based on extreme learning machine (ELM is proposed. The underlying factors that may affect urban rail dwell time are analyzed first. Then, the relationships among different factors are extracted and modeled by ELM neural networks, on basis of which an overall estimation model is proposed. At last, a set of observed data from Beijing subway is used to illustrate the proposed method and verify its overall performance.

  10. Explaining Student Behavior at Scale : The Influence of Video Complexity on Student Dwelling Time

    NARCIS (Netherlands)

    Sluis, van der F.; Ginn, J.H.; Zee, van der T.; Haywood, J.; Aleven, V.; Kay, J.; Roll, I.

    2016-01-01

    Understanding why and how students interact with educational videos is essential to further improve the quality of MOOCs. In this paper, we look at the complexity of videos to explain two related aspects of student behavior: the dwelling time (how much time students spend watching a video) and the

  11. Use of dwell time concept in fission product inventory assessment for CANDU reactors

    International Nuclear Information System (INIS)

    Bae, C.J.; Choi, J.H.; Hwang, H.R.; Seo, J.T.

    2003-01-01

    A realistic approach in calculating the initial fission product inventory within the CANFLEX-NU fuel has been assessed for its applicability to the single channel event safety analysis for CANDU reactors. This approach is based on the dwell time concept in which the accident is assumed to occur at the dwell time when the summation of fission product inventory for all isotopes becomes largest. However, in the current conservative analysis, the maximum total inventory and the corresponding gap inventory for each isotope are used as the initial fission product inventories regardless of the accident initiation time. The fission product inventory analysis has been performed using ELESTRES code considering power histories and burnup of the fuel bundles in the limiting channel. The analysis results showed that the total fission product inventory is found to be largest at 20% dwell time. Therefore, the fission product inventory at 20% dwell time can be used as the initial condition for the single channel event for the CANDU 6 reactors. (author)

  12. Non-uniform dwell times in line source high dose rate brachytherapy: physical and radiobiological considerations

    International Nuclear Information System (INIS)

    Jones, B.; Tan, L.T.; Freestone, G.; Bleasdale, C.; Myint, S.; Littler, J.

    1994-01-01

    The ability to vary source dwell times in high dose rate (HDR) brachytherapy allows for the use of non-uniform dwell times along a line source. This may have advantages in the radical treatment of tumours depending on individual tumour geometry. This study investigates the potential improvements in local tumour control relative to adjacent normal tissue isoeffects when intratumour source dwell times are increased along the central portion of a line source (technique A) in radiotherapy schedules which include a relatively small component of HDR brachytherapy. Such a technique is predicted to increase the local control for tumours of diameters ranging between 2 cm and 4 cm by up to 11% compared with a technique in which there are uniform dwell times along the line source (technique B). There is no difference in the local control rates for the two techniques when used to treat smaller tumours. Normal tissue doses are also modified by the technique used. Technique A produces higher normal tissue doses at points perpendicular to the centre of the line source and lower dose at points nearer the ends of the line source if the prescription point is not in the central plane of the line source. Alternatively, if the dose is prescribed at a point in the central plane of the line source, the dose at all the normal tissue points are lower when technique A is used. (author)

  13. Influence of overloads on dwell time fatigue crack growth in Inconel 718

    Energy Technology Data Exchange (ETDEWEB)

    Saarimäki, Jonas, E-mail: jonas.saarimaki@liu.se [Division of Engineering Materials, Department of Management and Engineering, Linköping University, SE-58183 Linköping (Sweden); Moverare, Johan [Division of Engineering Materials, Department of Management and Engineering, Linköping University, SE-58183 Linköping (Sweden); Siemens Industrial Turbomachinery AB, Materials Technology, SE-61283 Finspång (Sweden); Eriksson, Robert; Johansson, Sten [Division of Engineering Materials, Department of Management and Engineering, Linköping University, SE-58183 Linköping (Sweden)

    2014-08-26

    Inconel 718 is one of the most commonly used superalloys for high temperature applications in gasturbines and aeroengines and is for example used for components such as turbine discs. Turbine discs can be subjected to temperatures up to ∼700 °C towards the outer radius of the disc. During service, the discs might start to develop cracks due to fatigue and long dwell times. Additionally, temperature variations during use can lead to large thermal transients during start-up and shutdown which can lead to overload peaks in the normal dwell time cycle. In this study, tests at 550 °C with an overload prior to the start of each dwell time, have been performed. The aim of the investigation was to get a better understanding of the effects of overloads on the microstructure and crack mechanisms. The microstructure was studied using electron channelling contrast imaging (ECCI). The image analysis toolbox in Matlab was used on cross sections of the cracks to quantify: crack length, branch length, and the number of branches in each crack. It was found that the amount of crack branching increases with an increasing overload and that the branch length decreases with an increasing overload. When the higher overloads were applied, the dwell time effect was almost cancelled out. There is a strong tendency for an increased roughness of the crack path with an increasing crack growth rate.

  14. Influence of overloads on dwell time fatigue crack growth in Inconel 718

    International Nuclear Information System (INIS)

    Saarimäki, Jonas; Moverare, Johan; Eriksson, Robert; Johansson, Sten

    2014-01-01

    Inconel 718 is one of the most commonly used superalloys for high temperature applications in gasturbines and aeroengines and is for example used for components such as turbine discs. Turbine discs can be subjected to temperatures up to ∼700 °C towards the outer radius of the disc. During service, the discs might start to develop cracks due to fatigue and long dwell times. Additionally, temperature variations during use can lead to large thermal transients during start-up and shutdown which can lead to overload peaks in the normal dwell time cycle. In this study, tests at 550 °C with an overload prior to the start of each dwell time, have been performed. The aim of the investigation was to get a better understanding of the effects of overloads on the microstructure and crack mechanisms. The microstructure was studied using electron channelling contrast imaging (ECCI). The image analysis toolbox in Matlab was used on cross sections of the cracks to quantify: crack length, branch length, and the number of branches in each crack. It was found that the amount of crack branching increases with an increasing overload and that the branch length decreases with an increasing overload. When the higher overloads were applied, the dwell time effect was almost cancelled out. There is a strong tendency for an increased roughness of the crack path with an increasing crack growth rate

  15. Radon studies in Indian dwellings

    International Nuclear Information System (INIS)

    Khan, A.J.

    2000-01-01

    The indoor radon ( 222 Rn) concentration has been measured by Solid State Nuclear Track Detectors (SSNTDs) in large number of Indian dwellings. Radon concentrations were measured in different parts of the country. In the first study, radon concentrations were measured in 143 dwellings of Udaipur, Bikaner and Banswara towns of Rajasthan province. The distributions of the time-averaged indoor radon concentration in these three towns of the Rajasthan fit an approximately log normal distribution. The geometric mean (GM) values of radon concentrations in these three places were found to be 74 Bq m -3 , 46 Bq m -3 and 66 Bq m -3 with a geometric standard deviation (GSD) of 2.2, 2.2 and 2.5 respectively. In another study, radon concentrations were measured in about 150 dwellings of hilly regions of the country. The measurements were carried out in Kohima (Nagaland), Baijnath and Palampur (Himachal Pradesh). The distribution of radon concentration in Kohima dwellings was found to be approximately log normal, however, the radon distribution in Baijnath and Palampur dwellings seems to be bimodal. The GM values of the radon concentrations for 65 dwellings in Kohima and 43 dwellings in Baijnath and Palampur were 88 Bq m -3 and 134 Bq m -3 with GSD of 1.7 and 2.5 respectively. The results are discussed in detail. (author)

  16. The Simultaneous Vehicle Scheduling and Passenger Service Problem with Flexible Dwell Times

    DEFF Research Database (Denmark)

    Fonseca, Joao Filipe Paiva; Larsen, Allan; van der Hurk, Evelien

    In this talk, we deal with a generalization of the well-known Vehicle Scheduling Problem(VSP) that we call Simultaneous Vehicle Scheduling and Passenger Service Problem with Flexible Dwell Times (SVSPSP-FDT). The SVSPSP-FDT generalizes the VSP because the original timetables of the trips can...... be changed (i.e., shifted and stretched) in order to minimize a new objective function that aims at minimizing the operational costs plus the waiting times of the passengers at transfer points. Contrary to most generalizations of the VSP, the SVSPSP-FDT establishes the possibility of changing trips' dwell...... times at important transfer points based on expected passenger ows. We introduce a compact mixed integer linear formulation of the SVSPSP-FDT able to address small instances. We also present a meta-heuristic approach to solve medium/large instances of the problem. The e ectiveness of the proposed...

  17. Central line-associated bloodstream infections and catheter dwell-time: A theoretical foundation for a rule of thumb.

    Science.gov (United States)

    Voets, Philip J G M

    2018-05-14

    Many clinicians know from experience and medical epidemiological literature that the risk of central line-associated bloodstream infections (CLABSI) increases rapidly with a prolonged catheter dwell-time, but how this infection risk increases over time remains obscure. In this manuscript, a clinically useful rule of thumb is derived, stating that the risk of CLABSI increases in a quadratic fashion with the increase in catheter dwell-time. The proposed rule of thumb could be considered a quick and effortless clinical tool to rationally predict the pattern of CLABSI risk with an increasing catheter dwell-time. Copyright © 2018. Published by Elsevier Ltd.

  18. Social anxiety is related to increased dwell time on socially threatening faces.

    Science.gov (United States)

    Lazarov, Amit; Abend, Rany; Bar-Haim, Yair

    2016-03-15

    Identification of reliable targets for therapeutic interventions is essential for developing evidence-based therapies. Threat-related attention bias has been implicated in the etiology and maintenance of social anxiety disorder. Extant response-time-based threat bias measures have demonstrated limited reliability and internal consistency. Here, we examined gaze patterns of socially anxious and nonanxious participants in relation to social threatening and neutral stimuli using an eye-tracking task, comprised of multiple threat and neutral stimuli, presented for an extended time-period. We tested the psychometric properties of this task with the hope to provide a solid stepping-stone for future treatment development. Eye gaze was tracked while participants freely viewed 60 different matrices comprised of eight disgusted and eight neutral facial expressions, presented for 6000ms each. Gaze patterns on threat and neutral areas of interest (AOIs) of participants with SAD, high socially anxious students and nonanxious students were compared. Internal consistency and test-retest reliability were evaluated. Participants did not differ on first-fixation variables. However, overall, socially anxious students and participants with SAD dwelled significantly longer on threat faces compared with nonanxious participants, with no difference between the anxious groups. Groups did not differ in overall dwell time on neutral faces. Internal consistency of total dwell time on threat and neutral AOIs was high and one-week test-retest reliability was acceptable. Only disgusted facial expressions were used. Relative small sample size. Social anxiety is associated with increased dwell time on socially threatening stimuli, presenting a potential target for therapeutic intervention. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. [Assertiveness and peripheral intravenous catheters dwell time with ultrasonography-guided insertion in children and adolescents].

    Science.gov (United States)

    Avelar, Ariane Ferreira Machado; Peterlini, Maria Angélica Sorgini; da Pedreira, Mavilde Luz Gonçalves

    2013-06-01

    Randomized controlled trial which aimed to verify whether the use of vascular ultrasound (VUS) increases assertiveness in the use of peripheral venous catheter in children, and the catheter dwell time, when compared to traditional puncture. Data were collected after approval of theethical merit. Children and adolescents undergoing VUS-guided peripheral intravenous (GVUS) or puncture guided by clinical assessment of the venous conditions(CG) were included in the study. Significance level was set at pAssertiveness was found in 73 (71.6%) GVUS catheters and in 84(71.8%) of the CG (p=0.970), and catheter dwell time presented a median of less than one day in both groups (p=0.121), showing nostatistically significant difference. VUS did not significantly influence the results of the dependent variables investigated. ClinicalTrials.govNCT00930254.

  20. Ureteric stent dwelling time: a risk factor for post-ureteroscopy sepsis.

    Science.gov (United States)

    Nevo, Amihay; Mano, Roy; Baniel, Jack; Lifshitz, David A

    2017-07-01

    To evaluate the association between stent dwelling time and sepsis after ureteroscopy, and identify risk factors for sepsis in this setting. The prospectively collected database of a single institution was queried for all patients who underwent ureteroscopy for stone extraction between 2010 and 2016. Demographic, clinical, preoperative and operative data were collected. The primary study endpoint was sepsis within 48 h of ureteroscopy. Logistic regressions were performed to identify predictors of post-ureteroscopy sepsis in the ureteroscopy cohort and specifically in patients with prior stent insertion. Between October 2010 and April 2016, 1 256 patients underwent ureteroscopy for stone extraction. Risk factors for sepsis included prior stent placement, female gender and Charlson comorbidity index. A total of 601 patients had a ureteric stent inserted before the operation and were included in the study cohort, in which the median age was 56 years, 90 patients were women (30%), and 97 patients were treated for positive preoperative urine cultures (16.1%). Postoperative sepsis, Sepsis rates after stent dwelling times of 1, 2, 3 and >3 months were 1, 4.9, 5.5 and 9.2%, respectively. On multivariate analysis, stent dwelling time, stent insertion because of sepsis, and female gender were significantly associated with post-ureteroscopy sepsis in patients with prior stent placement. Patients who undergo ureteroscopy after ureteric stent insertion have a higher risk of postoperative sepsis. Prolonged stent dwelling time, sepsis as an indication for stent insertion, and female gender are independent risk factors. Stent placement should be considered cautiously, and if inserted, ureteroscopy should be performed within 1 month. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

  1. Infinite dwell time and group delay in resonant electron tunneling through double complex potential barrier

    Science.gov (United States)

    Opacak, Nikola; Milanović, Vitomir; Radovanović, Jelena

    2017-12-01

    Tunneling times in complex potentials are investigated. Analytical expressions for dwell time, self-interference time and group delay are obtained for the case of complex double delta potentials. It is shown that we can always find a set of parameters of the potential so that the tunneling times achieve very large values and even approach infinity for the case of resonance. The phenomenon of infinite tunneling times occurs for only one particular positive value of the imaginary part of the potential, if all other parameters are given.

  2. Spatial and vertical distribution of radon and thoron in a typical Indian dwelling

    International Nuclear Information System (INIS)

    Vinay Kumar Reddy, K.; Gopal Reddy, Ch.; Yadagiri Reddy, P.; Rama Reddy, K.

    2012-01-01

    Radon and thoron have been identified as potential radiological health hazard and the dose estimation due to their exposure is an important task. Understanding their behavior in indoor environment helps in calculating the inhalation doses due to them. Present study aims at the distribution of radon and thoron concentrations in a typical Indian dwelling. Solid state nuclear track detectors are employed in the study. The concentration of radon is found to be invariant in indoor environment. The thoron concentration is found to decrease exponentially as a function of distance from the source (wall/floor). Solution of one dimensional diffusion equation is used for regression fittings for thoron variation, from which the diffusion constants and the exhalation rates were calculated. The diffusion constants varied from 0.00195 to 0.00540 m 2 s -1 . (author)

  3. PERCEPATAN DWELLING TIME : STRATEGI PENINGKATAN KINERJA PERDAGANGAN INTERNASIONAL PELABUHAN TANJUNG PRIOK

    Directory of Open Access Journals (Sweden)

    Wahyu Septi Utami

    2017-06-01

    Full Text Available Penelitian ini memiliki bertujuan untuk menganalisis strategi kebijakan yang dapat diimplementasikan untuk mempercepat waktu tinggal di pelabuhan Tanjung Priok, dalam rangka meningkatkan kinerja dalam perdagangan internasional. Penelitian ini menunjukkan hasil analisis dari wadah perhitungan impor tinggal waktu di Pelabuhan Tanjung Priok yang saat tinggal di pelabuhan Tanjung Priok pada 2013 adalah 8,59 hari, menunjukkan tinggal waktu masih di bawah standar kelayakan berdasarkan Peraturan Pemerintah Nomor 26 Tahun 2012 tentang Cetak    Biru Sistem Logistik Pembangunan Nasional adalah 3 hari. Berdasarkan hasil analisis SWOT disimpulkan bahwa kinerja Pelabuhan Tanjung Priok berada di quadran saya posisi (1,24; 1,25 Strategi yang digunakan untuk meningkatkan Pelabuhan Tanjung Priok SO tinggal waktu, yaitu meningkatkan jumlah jalur importir MITA, memperbanyak sejajar dengan bea cukai, insentif untuk awal PIB, mengoptimalkan INSW dan adat istiadat, meningkatkan kerjasama para pemangku kepentingan, membangun Cikarang Dry Port (CDP sebagai perluasan dari Komisi Pemilihan Umum Bea Pelabuhan Tanjung Priok.  This research had an aims to to analyze the policy strategies that can be implemented to accelerate the dwelling time at Tanjung Priok port, in order to improve performance in international trade. This research showed results of analysis of container import calculation dwelling time at Tanjung Priok Port that the dwelling time  at Tanjung Priok port in 2013 was 8,59 days, indicating dwelling time is still below standard eligibility is based on Government Regulation No. 26 Year 2012 on the Blueprint of the National Logistics System Development is 3 days. Based on the results of the SWOT analysis concluded that the performance of the Tanjung Priok Port was in quadran I the position (1,24; 1,25 Strategies used to improve the Port of Tanjung Priok is SO dwelling time, ie increasing the number of lanes importers MITA, multiply the parallel to the

  4. Increasing dwell time of mitomycin C in the upper tract with a reverse thermosensitive polymer.

    Science.gov (United States)

    Wang, Agnes J; Goldsmith, Zachariah G; Neisius, Andreas; Astroza, Gaston M; Oredein-McCoy, Olugbemisola; Iqbal, Muhammad W; Simmons, W Neal; Madden, John F; Preminger, Glenn M; Inman, Brant A; Lipkin, Michael E; Ferrandino, Michael N

    2013-03-01

    Abstract Background and Purpose: Topical chemotherapy for urothelial cancer is dependent on adequate contact time of the chemotherapeutic agent with the urothelium. To date, there has not been a reliable method of maintaining this contact for renal or ureteral urothelial carcinoma. We evaluated the safety and feasibility of using a reverse thermosensitive polymer to improve dwell times of mitomycin C (MMC) in the upper tract. Using a porcine model, four animals were treated ureteroscopically with both upper urinary tracts receiving MMC mixed with iodinated contrast. One additional animal received MMC percutaneously. The treatment side had ureteral outflow blocked with a reverse thermosensitive polymer plug. MMC dwell time was monitored fluoroscopically and intrarenal pressures measured. Two animals were euthanized immediately, and three animals were euthanized 5 days afterward. In control kidneys, drainage occurred at a mean of 5.3±0.58 minutes. Intrarenal pressures stayed fairly stable: 9.7±14.0 cm H20. In treatment kidneys, dwell time was extended to 60 minutes, when the polymer was washed out. Intrarenal pressures in the treatment kidneys peaked at 75.0±14.7 cm H20 and reached steady state at 60 cm H20. Pressures normalized after washout of the polymer with cool saline. Average washout time was 11.8±9.6 minutes. No histopathologic differences were seen between the control and treatment kidneys, or with immediate compared with delayed euthanasia. A reverse thermosensitive polymer can retain MMC in the upper urinary tract and appears to be safe from our examination of intrarenal pressures and histopathology. This technique may improve the efficacy of topical chemotherapy in the management of upper tract urothelial carcinoma.

  5. Dwell time, Hartman effect and transport properties in a ferromagnetic phosphorene monolayer.

    Science.gov (United States)

    Hedayati Kh, Hamed; Faizabadi, Edris

    2018-02-28

    In this paper, spin-dependent dwell time, spin Hartman effect and spin-dependent conductance were theoretically investigated through a rectangular barrier in the presence of an exchange field by depositing a ferromagnetic insulator on the phosphorene layer in the barrier region. The existence of the spin Hartman effect was shown for all energies (energies lower than barrier height) and all incident angles in phosphorene. We also compared our results of the dwell time in the phosphorene structure with similar research performed on graphene. We reported a significant difference between the tunneling time values of incident quasiparticles with spin-up and spin-down. We found that the barrier was almost transparent for incident quasiparticles with a wide range of incident angles and energies higher than the barrier height in phosphorene. We also found that the maximum spin-dependent transmission probability for energies higher than barrier height does not necessarily occur in the zero incident angle. In addition, we showed that the spin conductance for energies higher (lower) than barrier height fluctuates (decays) in terms of barrier thickness. We discovered that, in contrast to graphene, the Klein paradox does not occur in the normal incident in the phosphorene structure. Furthermore, the results demonstrated the achievement of good total conductance at certain thicknesses of the barrier for energies higher than the barrier height. This study could serve as a basis for investigations of the basic physics of tunneling mechanisms and also for using phosphorene as a spin polarizer in designing nanoelectronic devices.

  6. Dwell time, Hartman effect and transport properties in a ferromagnetic phosphorene monolayer

    Science.gov (United States)

    Hedayati Kh, Hamed; Faizabadi, Edris

    2018-02-01

    In this paper, spin-dependent dwell time, spin Hartman effect and spin-dependent conductance were theoretically investigated through a rectangular barrier in the presence of an exchange field by depositing a ferromagnetic insulator on the phosphorene layer in the barrier region. The existence of the spin Hartman effect was shown for all energies (energies lower than barrier height) and all incident angles in phosphorene. We also compared our results of the dwell time in the phosphorene structure with similar research performed on graphene. We reported a significant difference between the tunneling time values of incident quasiparticles with spin-up and spin-down. We found that the barrier was almost transparent for incident quasiparticles with a wide range of incident angles and energies higher than the barrier height in phosphorene. We also found that the maximum spin-dependent transmission probability for energies higher than barrier height does not necessarily occur in the zero incident angle. In addition, we showed that the spin conductance for energies higher (lower) than barrier height fluctuates (decays) in terms of barrier thickness. We discovered that, in contrast to graphene, the Klein paradox does not occur in the normal incident in the phosphorene structure. Furthermore, the results demonstrated the achievement of good total conductance at certain thicknesses of the barrier for energies higher than the barrier height. This study could serve as a basis for investigations of the basic physics of tunneling mechanisms and also for using phosphorene as a spin polarizer in designing nanoelectronic devices.

  7. The influence of the dwell time deviation constraint (DTDC) parameter on dosimetry with IPSA optimisation for HDR prostate brachytherapy

    International Nuclear Information System (INIS)

    Smith, Ryan L.; Millar, Jeremy L.; Panettieri, Vanessa; Mason, Natasha; Lancaster, Craig; Francih, Rick D.

    2015-01-01

    To investigate how the dwell time deviation constraint (DTDC) parameter, applied to inverse planning by simulated annealing (IPSA) optimisation limits large dwell times from occurring in each catheter and to characterise the effect on the resulting dosimetry for prostate high dose rate (HDR) brachytherapy treatment plans. An unconstrained IPSA optimised treatment plan, using the Oncentra Brachytherapy treatment planning system (version 4.3, Nucletron an Elekta company, Elekta AB, Stockholm, Sweden), was generated for 20 consecutive HDR prostate brachytherapy patients, with the DTDC set to zero. Successive constrained optimisation plans were also created for each patient by increasing the DTDC parameter by 0.2, up to a maximum value of 1.0. We defined a “plan modulation index”, to characterise the change of dwell time modulation as the DTDC parameter was increased. We calculated the dose volume histogram indices for the PTV (D90, V100, V150, V200%) and urethra (D10%) to characterise the effect on the resulting dosimetry. The average PTV D90% decreases as the DTDC is applied, on average by only 1.5 %, for a DTDC = 0.4. The measures of high dose regions in the PTV, V150 and V200%, increase on average by less than 5 and 2 % respectively. The net effect of DTDC on the modulation of dwell times has been characterised by the introduction of the plan modulation index. DTDC applied during IPSA optimisation of HDR prostate brachytherapy plans reduce the occurrence of large isolated dwell times within individual catheters. The mechanism by which DTDC works has been described and its effect on the modulation of dwell times has been characterised. The authors recommend using a DTDC parameter no greater than 0.4 to obtain a plan with dwell time modulation comparable to a geometric optimised plan. This yielded on average a 1.5 % decrease in PTV coverage and an acceptable increase in V150%, without compromising the urethral dose.

  8. Investigation of force, contact area, and dwell time in finger-tapping tasks on membrane touch interface.

    Science.gov (United States)

    Liu, Na; Yu, Ruifeng

    2018-06-01

    This study aimed to determine the touch characteristics during tapping tasks on membrane touch interface and investigate the effects of posture and gender on touch characteristics variables. One hundred participants tapped digits displayed on a membrane touch interface on sitting and standing positions using all fingers of the dominant hand. Touch characteristics measures included average force, contact area, and dwell time. Across fingers and postures, males exerted larger force and contact area than females, but similar dwell time. Across genders and postures, thumb exerted the largest force and the force of the other four fingers showed no significant difference. The contact area of the thumb was the largest, whereas that of the little finger was the smallest; the dwell time of the thumb was the longest, whereas that of the middle finger was the shortest. Relationships among finger sizes, gender, posture and touch characteristics were proposed. The findings helped direct membrane touch interface design for digital and numerical control products from hardware and software perspectives. Practitioner Summary: This study measured force, contact area, and dwell time in tapping tasks on membrane touch interface and examined effects of gender and posture on force, contact area, and dwell time. The findings will direct membrane touch interface design for digital and numerical control products from hardware and software perspectives.

  9. Radon in Norwegian dwellings

    International Nuclear Information System (INIS)

    Strand, T.; Green, B.M.R; Lomas, P.R.; Mangnus, K.; Stranden, E.

    1991-01-01

    Measurements of radon in indoor air have been made in a total of about 7500 randomly selected dwellings in Norway from all parts of the country. The number of selected dwellings in each municipality is about proportional to its population, except for the two largest municipalities, Oslo and Bergen, where somewhat smaller samples were taken due to the higher population density. The measurements were performed by nuclear track detectors from the National Radiological Protection Boards in United Kingdom, and the integration time for the measurements was 6 months. The detectors were spread evenly over all seasons of the year to eliminate influence from seasonal variation in the radon level. One single measurement was performed in each dwelling: in the main bedroom. The results shows that the distribution of radon concentrations in Norwegian bedrooms is log-normal. The aritmetic mean of the measurements, including all categories of dwellings, is calculated to be 51 Bq/m 3 and the corresponding geometric mean to be 26 Bq/m 3 . In a large proportion of single-family houses the living room and the kitchen are located on the ground floor while the bedrooms are located one floor higher. The results of the study shows that the radon level is somewhat higher at the ground floor than on the first floor, and higher in the basement than on the first floor. Taking this into account, and assuming that measurements in bedrooms on the first floor is a representative average for living room and kitchen, the average radon concentration for Norwegian dwellings is estimated to be between 55-65 Bq/m 3 . In this estimate, possible influences of the fact that the winters 87/88 and 88/89 were much warmer than normal and may therefor have lowered the results, has been taken into account. 15 refs., 9 figs., 15 tabs

  10. Stair negotiation time in community-dwelling older adults: normative values and association with functional decline.

    Science.gov (United States)

    Oh-Park, Mooyeon; Wang, Cuiling; Verghese, Joe

    2011-12-01

    To establish reference values for stair ascent and descent times in community-dwelling, ambulatory older adults, and to examine their predictive validity for functional decline. Longitudinal cohort study. Mean follow-up time was 1.8 years (maximum, 3.2y; total, 857.9 person-years). Community sample. Adults 70 years and older (N=513; mean age, 80.8 ± 5.1y) without disability or dementia. Not applicable. Time to ascend and descend 3 steps measured at baseline. A 14-point disability scale assessed functional status at baseline and at follow-up interviews every 2 to 3 months. Functional decline was defined as an increase in the disability score by 1 point during the follow-up period. The mean±SD stair ascent and descent times for 3 steps were 2.78 ± 1.49 and 2.83 ± 1.61 seconds, respectively. The proportion of self-reported and objective difficulty was higher with longer stair ascent and descent times (PRehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  11. Optimization of Solar Water Heating System under Time and Spatial Partition Heating in Rural Dwellings

    Directory of Open Access Journals (Sweden)

    Yanfeng Liu

    2017-10-01

    Full Text Available This paper proposes the application of time and spatial partition heating to a solar water heating system. The heating effect and system performance were analyzed under the continuous and whole space heating and time and spatial partition heating using TRNSYS. The results were validated by comparing with the test results of the demonstration building. Compared to continuous and whole space heating, the use of time and spatial partition heating increases the solar fraction by 16.5%, reduces the auxiliary heating by 7390 MJ, and reduces the annual operation cost by 2010 RMB. Under time and spatial partition heating, optimization analyses were conducted for the two system capacity parameters of the solar collector area and tank volume and the one operation parameter of auxiliary heater setting outlet temperature. The results showed that a reasonable choice of the solar collector area can reduce the dynamic annual cost, the increased tank volume is advantageous to heat storage, and the auxiliary heater setting outlet temperature have greater influence on the indoor heating effect. The advanced opening of solar water heating system and the normal opening of passive air vents are recommended. Based on the comparison of the two modes, the time and spatial partition heating technology is a better choice for rural dwellings.

  12. In-situ real time measurements of thermal comfort and comparison with the adaptive comfort theory in Dutch residential dwellings

    NARCIS (Netherlands)

    Ioannou, A.; Itard, L.C.M.; Agarwal, Tushar

    2018-01-01

    Indoor thermal comfort is generally assessed using the PMV or the adaptive model. This research presents the results obtained by in-situ real time measurements of thermal comfort and thermal comfort perception in 17 residential dwellings in the Netherlands. The study demonstrates the new

  13. Influence of dwell times on the thermomechanical fatigue behavior of a directionally solidified Ni-base superalloy

    Czech Academy of Sciences Publication Activity Database

    Guth, S.; Petráš, Roman; Škorík, Viktor; Kruml, Tomáš; Man, Jiří; Lang, K. H.; Polák, Jaroslav

    2015-01-01

    Roč. 80, NOV (2015), s. 426-433 ISSN 0142-1123 R&D Projects: GA MŠk(CZ) EE2.3.30.0063 Institutional support: RVO:68081723 Keywords : Nickel base superalloy * Thermomechanical fatigue * Dwell time * Lifetime behavior * Damage mechanisms Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.162, year: 2015

  14. Asynchronous L1-gain control of uncertain switched positive linear systems with dwell time.

    Science.gov (United States)

    Li, Yang; Zhang, Hongbin

    2018-04-01

    In this paper, dwell time (DT) stability, L 1 -gain performance analysis and asynchronous L 1 -gain controller design problems of uncertain switched positive linear systems (SPLSs) are investigated. Via a time-scheduled multiple linear co-positive Lyapunov function (TSMLCLF) approach, convex sufficient conditions of DT stability and L 1 -gain performance of SPLSs with interval and polytopic uncertainties are presented. Furthermore, by utilizing the feature that the TSMLCLF keeps decreasing even if the controller is running asynchronously with the system, the asynchronous L 1 -gain controller design problem of SPLSs with interval and polytopic uncertainties is investigated. Convex sufficient conditions of the existence of time-varying asynchronous state-feedback controller which can ensure the closed-loop system's positivity, stability and L 1 -gain performance are established, and the controller gain matrices can be calculated instantaneously online. The obtained L 1 -gain in the paper is standard. All the results are presented in terms of linear programming. A practical example is provided to show the effectiveness of the results. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  15. Distribution of 222Rn in dwellings around proposed uranium mining site at Rohil, Rajasthan

    International Nuclear Information System (INIS)

    Jha, V.N.; Kumar, Rajesh; Singh, M.K.; Patnaik, R.L.; Sahoo, S.K.; Jha, S.K.; Tripathi, R.M.

    2018-01-01

    Prior to commissioning of uranium ore mining and processing facility baseline radiological monitoring vis-a-vis public exposure assessment is required. Such information are utilized for developing control measures during operational phases to ascertain the minimal impact on the surrounding areas. Among the various pathways the inhalation component far exceeds the other component in the natural background of a region. Further, in inhalation component also the contribution of 222 Rn is almost 50%. The main sources of indoor radon are geological features, soil characteristics, construction materials of the dwellings, water utilization pattern, use of natural cooking gas, climatological/weather variables. As part of preliminary radiological assessment exercise twenty three dwellings were selected in this region comprising of different types of construction design/materials and passive radon dosimeters were provided of evaluation of radon level and inhalation exposure. The results presented in the text are part of the said radiological assessment exercise

  16. Life time fatality risk assessment due to variation of indoor radon concentration in dwellings in western Haryana, India

    International Nuclear Information System (INIS)

    Kansal, Sandeep; Mehra, Rohit; Singh, N.P.

    2012-01-01

    Indoor radon measurements in 60 dwellings belonging to 12 villages of Sirsa, Fatehbad and Hisar districts of western Haryana, India, have been carried out, using LR-115 type II cellulose nitrate films in the bare mode. The annual average indoor radon value in the studied area varies from 76.00 to 115.46 Bq m −3 , which is well within the recommended action level 200–300 Bq m −3 (). The winter/summer ratio of indoor radon ranges from 0.78 to 2.99 with an average of 1.52. The values of annual average dose received by the residents and Life time fatality risk assessment due to variation of indoor radon concentration in dwellings of studied area suggests that there is no significance threat to the human beings due to the presence of natural radon in the dwellings. - Highlights: ► The radon concentration values in the dwellings are 2–3 times more than the world average of 40 Bq m −3 . ► These values are lower than the recommended action level of 200–300 Bq m −3 (). ► The annual effective dose is less than the recommended action level of 3–10 mSv per year (). ► The values of life time fatality risk determined for the studied area are within safe standards. ► There is no significant threat to the human beings due to the presence of natural radon in the dwellings.

  17. Radon-thoron levels and inhalation dose distribution patterns in India dwellings

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Eappen, K.P.; Nair, R.N.; Mayya, Y.S.; Sadasivan, S.

    2003-09-01

    A countrywide survey on radon and thoron levels has been carried out in Indian dwellings under a Coordinated Research Project sponsored by the Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy (DAE). Eight universities and a few research institutions from different parts of the country participated in this project. Under this project, radon and thoron levels were measured using Solid State Nuclear Track Detector (SSNTD) -spark counter based passive technique. A plastic twin chamber radon -thoron dosimeter was developed and standardized for the survey. This radon-thoron discriminating dosimeter uses three SSNTDs; two of which are exposed in cup modes and the third one is exposed in bare mode. Calibration factors (CF) are obtained for cup and bare mode SSNTDs through controlled experiments in a calibration facility. Calibration factors obtained from experiments showed very good agreement with the calibration factors derived from theoretical models. Four nodal centres were set up each at Kalpakkam, Jodhpur, Jaduguda and Mumbai for calibration and standardization of the dosimeter system. Inter calibration of the dosimeters were also carried out for comparison purpose. Nearly 4500 measurements in about 1400 dwellings were made during the survey period. An analysis of the data shows that the indoor radon gas concentrations at different locations vary between 4.6 and 147.0 Bq.m -3 with a geometric mean of 23.0 Bq.m -3 (GSD 2.61). Indoor thoron gas concentrations, in general, are found to be less than the radon concentrations and vary from 3.6 to 42.8 Bq.m -3 with a geometric mean of 12.2 Bq.m -3 (GSD 3.22). The mean annual inhalation dose rate due to radon, thoron and their progeny in the dwellings is estimated to be 0.97 mSv.y -1 (GSD 2.49). It is observed that the major contribution to the indoor inhalation dose is due to radon and its progeny. However, the contribution due to thoron and its progeny is not trivial as it is about 20 % of the total

  18. Distributed space-time coding

    CERN Document Server

    Jing, Yindi

    2014-01-01

    Distributed Space-Time Coding (DSTC) is a cooperative relaying scheme that enables high reliability in wireless networks. This brief presents the basic concept of DSTC, its achievable performance, generalizations, code design, and differential use. Recent results on training design and channel estimation for DSTC and the performance of training-based DSTC are also discussed.

  19. Dwell Time and Surface Parameter Effects on Removal of Silicone Oil From D6ac Steel Using TCA

    Science.gov (United States)

    Boothe, R. E.

    2003-01-01

    This study was conducted to evaluate the impact of dwell time, surface roughness, and the surface activation state on 1,1,1-trichloroethane's (TCA's) effectiveness for removing silicone oil from D6ac steel. Silicone-contaminated test articles were washed with TCA solvent, and then the surfaces were analyzed for residue, using Fourier transform infrared spectroscopy. The predominant factor affecting the ability to remove the silicone oil was surface roughness.

  20. An impaired attentional dwell time after parietal and frontal lesions related to impaired selective attention not unilateral neglect.

    Science.gov (United States)

    Correani, Alessia; Humphreys, Glyn W

    2011-07-01

    The attentional blink, a measure of the temporal dynamics of visual processing, has been documented to be more pronounced following brain lesions that are associated with visual neglect. This suggests that, in addition to their spatial bias in attention, neglect patients may have a prolonged dwell time for attention. Here the attentional dwell time was examined in patients with damage focused on either posterior parietal or frontal cortices. In three experiments, we show that there is an abnormally pronounced attentional dwell time, which does not differ in patients with posterior parietal and with frontal lobe lesions, and this is associated with a measure of selective attention but not with measures of spatial bias in selection. These data occurred both when we attempted to match patients and controls for overall differences in performance and when a single set stimulus exposure was used across participants. In Experiments 1 and 2, requiring report of colour-form conjunctions, there was evidence that the patients were also impaired at temporal binding, showing errors in feature combination across stimuli and in reporting in the correct temporal order. In Experiment 3, requiring only the report of features but introducing task switching led to similar results. The data suggest that damage to a frontoparietal network can compromise temporal selection of visual stimuli; however, this is not necessarily related to a deficit in hemispatial visual attention but it is to impaired target selection. We discuss the implications for understanding visual selection.

  1. Distributed synthesis in continuous time

    DEFF Research Database (Denmark)

    Hermanns, Holger; Krčál, Jan; Vester, Steen

    2016-01-01

    We introduce a formalism modelling communication of distributed agents strictly in continuous-time. Within this framework, we study the problem of synthesising local strategies for individual agents such that a specified set of goal states is reached, or reached with at least a given probability....... The flow of time is modelled explicitly based on continuous-time randomness, with two natural implications: First, the non-determinism stemming from interleaving disappears. Second, when we restrict to a subclass of non-urgent models, the quantitative value problem for two players can be solved in EXPTIME....... Indeed, the explicit continuous time enables players to communicate their states by delaying synchronisation (which is unrestricted for non-urgent models). In general, the problems are undecidable already for two players in the quantitative case and three players in the qualitative case. The qualitative...

  2. Experimental investigation on low cycle fatigue and creep-fatigue interaction of DZ125 in different dwell time at elevated temperatures

    International Nuclear Information System (INIS)

    Shi Duoqi; Liu Jinlong; Yang Xiaoguang; Qi Hongyu; Wang Jingke

    2010-01-01

    Research highlights: → This paper has researched creep-fatigue interaction of directionally solidified superalloy DZ125 with different dwell time at high temperature combined with micro-mechanism by experiment. → The results indicated that the life of creep-fatigue decreases as dwell time increases, but the life of this alloy was almost unchanged when dwell time exceeds a critical value at 850 deg. C. - Abstract: The low cycle fatigue (LCF) and creep-fatigue tests have been conducted with directionally solidified nickel-based superalloy DZ125 at 850 and 980 deg. C to study the creep-fatigue interaction behavior of alloy with different dwell time. On the average, the life of creep-fatigue tests are about 70% less than the life of LCF tests under the same strain range at 850 deg. C. The life of creep-fatigue decreases as dwell time increases, but the life of this alloy was almost unchanged when dwell time exceeds a critical value at 850 deg. C. Scanning electron microscope (SEM) analyses of the fracture revealed that the fracture modes were influenced by different way of loading. In case of LCF, the primary fracture mode was transgranular, while in case of creep-fatigue, the primary fracture mode was mixed with transgranular and intergranular. There were also obvious different morphologies of surface crack between LCF and creep-fatigue.

  3. Effects of dwell time of excitation waveform on meniscus movements for a tubular piezoelectric print-head: experiments and model

    Science.gov (United States)

    Chang, Jiaqing; Liu, Yaxin; Huang, Bo

    2017-07-01

    In inkjet applications, it is normal to search for an optimal drive waveform when dispensing a fresh fluid or adjusting a newly fabricated print-head. To test trial waveforms with different dwell times, a camera and a strobe light were used to image the protruding or retracting liquid tongues without ejecting any droplets. An edge detection method was used to calculate the lengths of the liquid tongues to draw the meniscus movement curves. The meniscus movement is determined by the time-domain response of the acoustic pressure at the nozzle of the print-head. Starting at the inverse piezoelectric effect, a mathematical model which considers the liquid viscosity in acoustic propagation is constructed to study the acoustic pressure response at the nozzle of the print-head. The liquid viscosity retards the propagation speed and dampens the harmonic amplitude. The pressure response, which is the combined effect of the acoustic pressures generated during the rising time and the falling time and after their propagations and reflections, explains the meniscus movements well. Finally, the optimal dwell time for droplet ejections is discussed.

  4. Effects of dwell time of excitation waveform on meniscus movements for a tubular piezoelectric print-head: experiments and model

    International Nuclear Information System (INIS)

    Chang, Jiaqing; Liu, Yaxin; Huang, Bo

    2017-01-01

    In inkjet applications, it is normal to search for an optimal drive waveform when dispensing a fresh fluid or adjusting a newly fabricated print-head. To test trial waveforms with different dwell times, a camera and a strobe light were used to image the protruding or retracting liquid tongues without ejecting any droplets. An edge detection method was used to calculate the lengths of the liquid tongues to draw the meniscus movement curves. The meniscus movement is determined by the time-domain response of the acoustic pressure at the nozzle of the print-head. Starting at the inverse piezoelectric effect, a mathematical model which considers the liquid viscosity in acoustic propagation is constructed to study the acoustic pressure response at the nozzle of the print-head. The liquid viscosity retards the propagation speed and dampens the harmonic amplitude. The pressure response, which is the combined effect of the acoustic pressures generated during the rising time and the falling time and after their propagations and reflections, explains the meniscus movements well. Finally, the optimal dwell time for droplet ejections is discussed. (paper)

  5. Dutch Dwellings

    NARCIS (Netherlands)

    Vries, de B.; Zee, van der A.; Carp, J.C.; Soddu, C.

    2004-01-01

    Applying Generative Design (GD) for dwelling is not very common but it opens up the possibility to study whether GD systems can reproduce existing design typologies. Dutch dwellings as an exemplification of a design typology are analysed using the SAR methodology. Building regulations are used as

  6. The physical capabilities underlying timed "Up and Go" test are time-dependent in community-dwelling older women.

    Science.gov (United States)

    Coelho-Junior, Hélio José; Rodrigues, Bruno; Gonçalves, Ivan de Oliveira; Asano, Ricardo Yukio; Uchida, Marco Carlos; Marzetti, Emanuele

    2018-04-01

    Timed 'Up and Go' (TUG) has been widely used in research and clinical practice to evaluate physical function and mobility in older adults. However, the physical capabilities underlying TUG performance are not well elucidated. Therefore, the present study aimed at investigating a selection of physical capacities underlying TUG performance in community-dwelling older women. Four hundred and sixty-eight apparently healthy older women independent to perform the activities of daily living (mean age: 65.8 ± 6.0 years) were recruited from two specialized healthcare centers for older adults to participate in the study. Volunteers had their medical books reviewed and underwent evaluations of anthropometric data as well as physical and functional capacities. Pearson's correlation results indicate that TUG performance was significantly associated with upper (i.e., handgrip strength) and lower (i.e., sit-to-stand) limb muscle strength, balance (i.e., one-leg stand), lower limb muscle power (i.e., countermovement jump), aerobic capacity (i.e., 6-minute walk test), and mobility (i.e., usual and maximal walking speeds). When the analyses were performed based on TUG quartiles, a larger number of physical capabilities were associated with TUG >75% in comparison with TUG <25%. Multiple linear regression results indicate that the variability in TUG (~20%) was explained by lower limb muscle strength (13%) and power (1%), balance (4%), mobility (2%), and aerobic capacity (<1%), even after adjusted by age and age plus body mass index (BMI). However, when TUG results were added as quartiles, a decrease in the impact of physical capacities on TUG performance was determined. As a whole, our findings indicate that the contribution of physical capabilities to TUG performance is altered according to the time taken to perform the test, so that older women in the lower quartiles - indicating a higher performance - have an important contribution of lower limb muscle strength, while

  7. Balancing out dwelling and moving: optimal sensorimotor synchronization

    Science.gov (United States)

    Girard, Benoît; Guigon, Emmanuel

    2015-01-01

    Sensorimotor synchronization is a fundamental skill involved in the performance of many artistic activities (e.g., music, dance). After a century of research, the manner in which the nervous system produces synchronized movements remains poorly understood. Typical rhythmic movements involve a motion and a motionless phase (dwell). The dwell phase represents a sizable fraction of the rhythm period, and scales with it. The rationale for this organization remains unexplained and is the object of this study. Twelve participants, four drummers (D) and eight nondrummers (ND), performed tapping movements paced at 0.5–2.5 Hz by a metronome. The participants organized their tapping behavior into dwell and movement phases according to two strategies: 1) Eight participants (1 D, 7 ND) maintained an almost constant ratio of movement time (MT) and dwell time (DT) irrespective of the metronome period. 2) Four participants increased the proportion of DT as the period increased. The temporal variabilities of both the dwell and movement phases were consistent with Weber's law, i.e., their variability increased with their durations, and the longest phase always exhibited the smallest variability. We developed an optimal statistical model that formalized the distribution of time into dwell and movement intervals as a function of their temporal variability. The model accurately predicted the participants' dwell and movement durations irrespective of their strategy and musical skill, strongly suggesting that the distribution of DT and MT results from an optimization process, dependent on each participant's skill to predict time during rest and movement. PMID:25878154

  8. Physical activity and not sedentary time per se influences on clustered metabolic risk in elderly community-dwelling women.

    Directory of Open Access Journals (Sweden)

    Andreas Nilsson

    Full Text Available Whether amount of time spent in sedentary activities influences on clustered metabolic risk in elderly, and to what extent such an influence is independent of physical activity behavior, remain unclear. Therefore, the aim of the study was to examine cross-sectional associations of objectively assessed physical activity and sedentary behavior on metabolic risk outcomes in a sample of elderly community-dwelling women.Metabolic risk outcomes including waist circumference, systolic and diastolic blood pressures, fasting levels of plasma glucose, HDL-cholesterol and triglycerides were assessed in 120 community-dwelling older women (65-70 yrs. Accelerometers were used to retrieve daily sedentary time, breaks in sedentary time, daily time in light (LPA and moderate-to-vigorous physical activity (MVPA, and total amount of accelerometer counts. Multivariate regression models were used to examine influence of physical activity and sedentary behavior on metabolic risk outcomes including a clustered metabolic risk score.When based on isotemporal substitution modeling, replacement of a 10-min time block of MVPA with a corresponding time block of either LPA or sedentary activities was associated with an increase in clustered metabolic risk score (β = 0.06 to 0.08, p < 0.05, and an increase in waist circumference (β = 1.78 to 2.19 p < 0.01. All associations indicated between sedentary time and metabolic risk outcomes were lost once variation in total accelerometer counts was adjusted for.Detrimental influence of a sedentary lifestyle on metabolic health is likely explained by variations in amounts of physical activity rather than amount of sedentary time per se. Given our findings, increased amounts of physical activity with an emphasis on increased time in MVPA should be recommended in order to promote a favorable metabolic health profile in older women.

  9. Shorter daily dwelling time in peritoneal dialysis attenuates the epithelial-to-mesenchymal transition of mesothelial cells

    Science.gov (United States)

    2014-01-01

    Background Peritoneal dialysis (PD) therapy is known to induce morphological and functional changes in the peritoneal membrane. Long-term exposure to conventional bio-incompatible dialysate and peritonitis is the main etiology of inflammation. Consequently, the peritoneal membrane undergoes structural changes, including angiogenesis, fibrosis, and hyalinizing vasculopathy, which ultimately results in technique failure. The epithelial-to-mesenchymal transition (EMT) of mesothelial cells (MCs) plays an important role during the above process; however, the clinical parameters associated with the EMT process of MCs remain to be explored. Methods To investigate the parameters impacting EMT during PD therapy, 53 clinical stable PD patients were enrolled. EMT assessments were conducted through human peritoneal MCs cultured from dialysate effluent with one consistent standard criterion (MC morphology and the expression of an epithelial marker, cytokeratin 18). The factors potentially associated with EMT were analyzed using logistic regression analysis. Primary MCs derived from the omentum were isolated for the in vitro study. Results Forty-seven percent of the patients presented with EMT, 28% with non-EMT, and 15% with a mixed presentation. Logistic regression analysis showed that patients who received persistent PD therapy (dwelling time of 24 h/day) had significantly higher EMT tendency. These results were consistent in vitro. Conclusions Dwelling time had a significant effect on the occurrence of EMT on MCs. PMID:24555732

  10. Response of different injector typologies to dwell time variations and a hydraulic analysis of closely-coupled and continuous rate shaping injection schedules

    International Nuclear Information System (INIS)

    Ferrari, A.; Mittica, A.

    2016-01-01

    Highlights: • Direct and indirect acting injectors are tested considering multiple injections. • The injection fusion threshold is higher for ballistic injectors than for stroke-end limited injectors. • The internal dynamics of the injector is analyzed for closely-coupled double injections. • Different regimes are identified and classified in the short dwell time range. • Innovative rate shaping injection schedules are defined for solenoid injectors. - Abstract: The multiple injection performance of Common Rail injectors has been analyzed at a hydraulic test rig as the dwell time was varied. The dependence of the injected volume on the dwell time has been investigated for direct acting piezoelectric and hydraulically-controlled (or indirect-acting) servo injectors. The injected fuel volumes in the long dwell-time range have been shown to be affected by the pressure waves that travel along the high pressure circuit for hydraulically-controlled servo injectors. On the other hand, the influence of pressure-wave-induced disturbances on multiple injection performance has been shown to be negligible for direct acting piezoelectric injectors. An analysis of closely-coupled injections has been conducted on a solenoid injector. When the dwell time is progressively reduced below a critical value, an increase in the fuel quantity that is injected in the second shot is observed. Injection fusion phenomena occur as the dwell time is diminished below a certain threshold and a maximum in the fuel volume, which is injected during the joint injections, is eventually detected for a very short electric dwell time value close to 100 μs. The cycle-to-cycle dispersion around this dwell time value results to be reduced significantly. A previously developed 1D model of the fuel injection system has been applied to analyze the injector transients. Detailed knowledge of the injection dynamics in the short dwell time region is of fundamental importance to optimize the

  11. Multi-Train Energy Saving for Maximum Usage of Regenerative Energy by Dwell Time Optimization in Urban Rail Transit Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Fei Lin

    2016-03-01

    Full Text Available With its large capacity, the total urban rail transit energy consumption is very high; thus, energy saving operations are quite meaningful. The effective use of regenerative braking energy is the mainstream method for improving the efficiency of energy saving. This paper examines the optimization of train dwell time and builds a multiple train operation model for energy conservation of a power supply system. By changing the dwell time, the braking energy can be absorbed and utilized by other traction trains as efficiently as possible. The application of genetic algorithms is proposed for the optimization, based on the current schedule. Next, to validate the correctness and effectiveness of the optimization, a real case is studied. Actual data from the Beijing subway Yizhuang Line are employed to perform the simulation, and the results indicate that the optimization method of the dwell time is effective.

  12. Repeated and time-correlated morphological convergence in cave-dwelling harvestmen (Opiliones, Laniatores from Montane Western North America.

    Directory of Open Access Journals (Sweden)

    Shahan Derkarabetian

    Full Text Available BACKGROUND: Many cave-dwelling animal species display similar morphologies (troglomorphism that have evolved convergent within and among lineages under the similar selective pressures imposed by cave habitats. Here we study such ecomorphological evolution in cave-dwelling Sclerobuninae harvestmen (Opiliones from the western United States, providing general insights into morphological homoplasy, rates of morphological change, and the temporal context of cave evolution. METHODOLOGY/PRINCIPAL FINDINGS: We gathered DNA sequence data from three independent gene regions, and combined these data with Bayesian hypothesis testing, morphometrics analysis, study of penis morphology, and relaxed molecular clock analyses. Using multivariate morphometric analysis, we find that phylogenetically unrelated taxa have convergently evolved troglomorphism; alternative phylogenetic hypotheses involving less morphological convergence are not supported by Bayesian hypothesis testing. In one instance, this morphology is found in specimens from a high-elevation stony debris habitat, suggesting that troglomorphism can evolve in non-cave habitats. We discovered a strong positive relationship between troglomorphy index and relative divergence time, making it possible to predict taxon age from morphology. Most of our time estimates for the origin of highly-troglomorphic cave forms predate the Pleistocene. CONCLUSIONS/SIGNIFICANCE: While several regions in the eastern and central United States are well-known hotspots for cave evolution, few modern phylogenetic studies have addressed the evolution of cave-obligate species in the western United States. Our integrative studies reveal the recurrent evolution of troglomorphism in a perhaps unexpected geographic region, at surprisingly deep time depths, and in sometimes surprising habitats. Because some newly discovered troglomorphic populations represent undescribed species, our findings stress the need for further biological

  13. Fine tuning of dwelling time in friction stir welding for preventing material overheating, weld tensile strength increase and weld nugget size decrease

    Directory of Open Access Journals (Sweden)

    Mijajlović Miroslav M.

    2016-01-01

    Full Text Available After successful welding, destructive testing into test samples from Al 2024-T351 friction stir butt welds showed that tensile strength of the weld improve along the joint line, while dimensions of the weld nugget decrease. For those welds, both the base material and the welding tool constantly cool down during the welding phase. Obviously, the base material became overheated during the long dwelling phase what made conditions for creation of joints with the reduced mechanical properties. Preserving all process parameters but varying the dwelling time from 5-27 seconds a new set of welding is done to reach maximal achievable tensile strength. An analytical-numerical-experimental model is used for optimising the duration of the dwelling time while searching for the maximal tensile strength of the welds

  14. Dwell-time effect on the synthesis of a nano-structured material in water by using Ni wire explosion

    International Nuclear Information System (INIS)

    Eom, Gyu Sub; Kwon, Hyeok Jung; Cho, Yong Sub; Paek, Kwang Hyun; Joo, Won Tae

    2014-01-01

    Nickel nano-structured materials are synthesized by using a wire explosion in water. Based on an analysis of each step of the wire explosion, we propose insufficient energy deposition before a plasma restrike as the cause for the inclusion of coarse particles in the wire-explosion product. We confirmed that more energy, in excess of 30%, could be deposited by increasing the dwell time, which resulted from a compression of vapor by the surrounding water and from suppression of plasma restrikes. Because of an increased energy loss into the surrounding water, the specific energy increased by two-fold compared to a gas atmosphere. The synthesized nano-structured nickel showed a uniform particle size of 20 nm with a few coarse particles that were mainly metallic nickel with a little oxide and hydroxide phases. The possibility for large-volume production through a continuous explosion of 300 shots was confirmed.

  15. Introducing a Third Timed Up & Go Test Trial Improves Performances of Hospitalized and Community-Dwelling Older Individuals

    DEFF Research Database (Denmark)

    Bloch, Mette Linding; R. Jønsson, Line R. Jønsson; T. Kristensen, Morten

    2017-01-01

    in hospitalized and community-dwelling older individuals. Methods: Eighty-two participants (50 from a geriatric hospital unit and 32 from an outpatient geriatric center; 52 women, 30 men) with a mean (SD) age of 83.6 (7.9) years were included in this cross-sectional study. All participants (except one from...... the hospital unit) performed 3 TUG trials, as fast as safely possible on the same day, and separated by up to 1-minute pauses. A rollator (4-wheeled rolling walker) was used as a standardized walking aid in the geriatric hospital unit, whereas participants used their normal walking aid (if any......) in the outpatient geriatric center. Results and Discussion: The fastest trial was trial 3 for 47 (57%), trial 2 for 25 (31%), and trial 1 for 10 (12%). Repeated-measures analyses of variance with Bonferroni corrections showed that TUG times improved from trial 1 to trial 3 (P

  16. On positivity of time-frequency distributions.

    NARCIS (Netherlands)

    Janssen, A.J.E.M.; Claasen, T.A.C.M.

    1985-01-01

    Consideration is given to the problem of how to regard the fundamental impossibility with time-frequency energy distributions of Cohen's class always to be nonnegative and, at the same time, to have correct marginal distributions. It is shown that the Wigner distribution is the only member of a

  17. Real-time modeling of heat distributions

    Science.gov (United States)

    Hamann, Hendrik F.; Li, Hongfei; Yarlanki, Srinivas

    2018-01-02

    Techniques for real-time modeling temperature distributions based on streaming sensor data are provided. In one aspect, a method for creating a three-dimensional temperature distribution model for a room having a floor and a ceiling is provided. The method includes the following steps. A ceiling temperature distribution in the room is determined. A floor temperature distribution in the room is determined. An interpolation between the ceiling temperature distribution and the floor temperature distribution is used to obtain the three-dimensional temperature distribution model for the room.

  18. Radon in Norwegian dwellings

    International Nuclear Information System (INIS)

    Strand, T.; Green, B.M.R.; Lomas, P.R.

    1992-01-01

    The results of a large-scale survey of radon concentrations in Norwegian dwellings are reported. Measurements of radon have been made in a total of 7500 dwellings. The dwellings were randomly selected and the number in each municipality is proportional to its population. The measurements were performed using etched track detectors from the National Radiological Protection Board in the UK. One detector was placed in the main bedroom in each dwelling for 6 months. The annual average of radon concentration in Norwegian bedrooms is calculated to be 51 Bq.m -3 . The frequency distribution is approximately log-normal with a geometric mean of 26 Bq.m -3 and about 4% of the bedrooms have concentrations above 200 Bq.m -3 . The radon concentrations are found to be about 40% higher for bedrooms in single-family houses than in blocks of flats and other multifamily houses. In a large proportion of single-family houses the living room and the kitchen are located on the ground floor and the bedrooms on the first floor. An additional factor is that the winters of 1987-1988 and 1988-1989 were much warmer than normal. Taking these factors into account, the average radon concentration in Norwegian dwellings is estimated to be between 55 and 65 Bq.m -3 . (author)

  19. Research in Distributed Real-Time Systems

    Science.gov (United States)

    Mukkamala, R.

    1997-01-01

    This document summarizes the progress we have made on our study of issues concerning the schedulability of real-time systems. Our study has produced several results in the scalability issues of distributed real-time systems. In particular, we have used our techniques to resolve schedulability issues in distributed systems with end-to-end requirements. During the next year (1997-98), we propose to extend the current work to address the modeling and workload characterization issues in distributed real-time systems. In particular, we propose to investigate the effect of different workload models and component models on the design and the subsequent performance of distributed real-time systems.

  20. Dwelling Designers

    Science.gov (United States)

    Szekely, George

    2012-01-01

    Children's inventions go far beyond track housing or Ethan Allen furniture; they foreshadow the most innovative ideas in building forms and interior designs. Children improvise with containers and find places in a home that suggest enticing dwellings. A drawer left open becomes a balcony, soap trays become cots, and the space between twin beds…

  1. Distributed time management in transputer networks

    NARCIS (Netherlands)

    Vervoort, Wiek; te West, R.; Schoute, Albert L.; Hofstede, J.

    1991-01-01

    For real-time applications in a distributed system a common notion of time is indispensable. Clocks are used for time measurement, determination of causality, process synchronization and generating unique identifications. All this is only possible if there is a time reference of specified accuracy.

  2. Archtecture of distributed real-time systems

    OpenAIRE

    Wing Leung, Cheuk

    2013-01-01

    CRAFTERS (Constraint and Application Driven Framework for Tailoring Embedded Real-time System) project aims to address the problem of uncertainty and heterogeneity in a distributed system by providing seamless, portable connectivity and middleware. This thesis contributes to the project by investigating the techniques that can be used in a distributed real-time embedded system. The conclusion is that, there is a list of specifications to be meet in order to provide a transparent and real-time...

  3. Raising the energy performance of historical dwellings

    NARCIS (Netherlands)

    van Krugten, L.T.F.; Hermans, L.M.C.; Havinga, L.C.; Pereira Roders, A.R.; Schellen, H.L.

    2016-01-01

    Purpose: Earlier studies assume that historical dwellings and post-war dwellings in particular, are less sustainable than modern dwellings, justifying its demolition. Over time, historical buildings have been transformed and their energy performance improved. However, there is little known on the

  4. Evolution of Self-Assembled Au NPs by Controlling Annealing Temperature and Dwelling Time on Sapphire (0001).

    Science.gov (United States)

    Lee, Jihoon; Pandey, Puran; Sui, Mao; Li, Ming-Yu; Zhang, Quanzhen; Kunwar, Sundar

    2015-12-01

    Au nanoparticles (NPs) have been utilized in a wide range of device applications as well as catalysts for the fabrication of nanopores and nanowires, in which the performance of the associated devices and morphology of nanopores and nanowires are strongly dependent on the size, density, and configuration of the Au NPs. In this paper, the evolution of the self-assembled Au nanostructures and NPs on sapphire (0001) is systematically investigated with the variation of annealing temperature (AT) and dwelling time (DT). At the low-temperature range between 300 and 600 °C, three distinct regimes of the Au nanostructure configuration are observed, i.e., the vermiform-like Au piles, irregular Au nano-mounds, and Au islands. Subsequently, being provided with relatively high thermal energy between 700 and 900 °C, the round dome-shaped Au NPs are fabricated based on the Volmer-Weber growth model. With the increased AT, the size of the Au NPs is gradually increased due to a more favorable surface diffusion while the density is gradually decreased as a compensation. On the other hand, with the increased DT, the size and density of Au NPs decrease due to the evaporation of Au at relatively high annealing temperature at 950 °C.

  5. Relative and Absolute Reliability of Timed Up and Go Test in Community Dwelling Older Adult and Healthy Young People

    Directory of Open Access Journals (Sweden)

    Farhad Azadi

    2014-01-01

    Full Text Available Objectives: Relative and absolute reliability are psychometric properties of the test that many clinical decisions are based on them. In many cases, only relative reliability takes into consideration while the absolute reliability is also very important. Methods & Materials: Eleven community-dwelling older adults aged 65 years and older (69.64±3.58 and 20 healthy young in the age range 20 to 35 years (28.80±4.15 using three versions of Timed Up and Go test were evaluated twice with an interval of 2 to 5 days. Results: Generally, the non-homogeneity of the study population was stratified to increase the Intra-class Correlation Coefficient (ICC this coefficient in elderly people is greater than young people and with a secondary task is reduced. In This study, absolute reliability indices using different data sources and equations lead to in more or less similar results. At general, in test–retest situations, the elderly more than the young people must be changed to be interpreted as a real change, not random. The random error contribution is slightly greater in elderly than young and with a secondary task is increased.It seems, heterogeneity leads to moderation in absolute reliability indices. Conclusion: In relative reliability studies, researchers and clinicians should pay attention to factors such as homogeneity of population and etc. As well as, absolute reliability beside relative reliability is needed and necessary in clinical decision making.

  6. Positivity of time-frequency distribution functions

    NARCIS (Netherlands)

    Janssen, A.J.E.M.

    1988-01-01

    This paper deals with the question how various 'natural' conditions posed on time-frequency distribution functions prevent them to be nonnegative everywhere for all signals. The attention is restricted mainly to distribution functions that involve the signal bilinearly. This paper summarizes and

  7. Distributed Algorithms for Time Optimal Reachability Analysis

    DEFF Research Database (Denmark)

    Zhang, Zhengkui; Nielsen, Brian; Larsen, Kim Guldstrand

    2016-01-01

    . We propose distributed computing to accelerate time optimal reachability analysis. We develop five distributed state exploration algorithms, implement them in \\uppaal enabling it to exploit the compute resources of a dedicated model-checking cluster. We experimentally evaluate the implemented...... algorithms with four models in terms of their ability to compute near- or proven-optimal solutions, their scalability, time and memory consumption and communication overhead. Our results show that distributed algorithms work much faster than sequential algorithms and have good speedup in general.......Time optimal reachability analysis is a novel model based technique for solving scheduling and planning problems. After modeling them as reachability problems using timed automata, a real-time model checker can compute the fastest trace to the goal states which constitutes a time optimal schedule...

  8. Borges in my office: the analysis of a man dwelling outside of time.

    Science.gov (United States)

    Shoshani, Michael; Shoshani, Batya

    2013-07-01

    This article weaves together two threads: the intricacies of the analysis of a difficult-to-reach yet extraordinary patient and the literary works of Jorge Luis Borges, which played a significant role in the analysis as a source of inspiration, enriching the analyst's reverie and opening up new psychic spaces. The authors demonstrate the analyst's recourse to several of Borges's stories in order to enrich his own inner world and to better understand the analysand. Some of these stories are briefly presented through the analyst's dialogue with them, and there is a discussion of their function in facilitating the process of working through issues of time, memory, mortality, and identity, contributing to the enhancement of the patient's ability to come face to face with the unwanted, split-off parts of his self and of reality. © 2013 The Psychoanalytic Quarterly, Inc.

  9. Using mid infrared technology as new method for the determination of the dwell time of salivary substitutes on three dimensional gingiva models

    Directory of Open Access Journals (Sweden)

    Karin Engelhart

    2016-03-01

    Full Text Available Abstract Background Many people suffer from dry mouth (xerostomia due to radiotherapy treatment of head and neck cancer, diseases like Sjogren’s syndrome or as adverse effects to prescribed medications. Salivary substitute products like gels or sprays are often used for treatment. Efficacy of those oral care products are regularly assessed by validated or even not validated questionnaires. To determine the adhesion effect over time more objectively a new and sensitive method was established. The following study was designed to assess the dwell time of different oral care products in vitro. Method Two different types of surfaces were covered with oral care products and washed using a definite protocol with artificial saliva salt solution. First, oral care gels or oral care sprays were spread to a polystyrene surface of 2.25 cm2, then onto cell based three-dimensional gingiva models. The surfaces were washed ten times with artificial saliva salt solution. The resulting washing solutions were examined using mid infrared spectroscopy in order to detect ingredients of the oral care products. Results All assessed oral care gels or oral care sprays and their components were detected very sensitive. Even traces of the products were detected in the eluent and thus enabled to differentiate the dwell times of the different products. In general, the dwell time of oral care gels on polystyrene or gingiva models was longer than that of oral care sprays. The use of gingiva models improved the differentiation between different products. Conclusions MIR spectroscopy turned out to be a sensitive method to detect salivary substitutes. Differences between single components and different products can be detected. The described method is a simple, reliable and easy process to evaluate the dwell time of oral care products in vitro and thus a useful tool to design optimised salivary substitute products. Ethics This is an in vitro study. No ethics or consent was

  10. Virtual Realities: How Remote Dwelling Populations Become More Remote Over Time despite Technological Improvements

    Directory of Open Access Journals (Sweden)

    Dean Carson

    2010-05-01

    Full Text Available For those who have access to them, technologies of various sorts play a key role in maintaining connections between small and geographically dispersed settlements and to the wider World. For technologies to work in remote areas, there must be a framework of adaptability which ensures that users can adapt their practices to suit the new technology, technologies can be customised for local conditions, and an institutional infrastructure (including a regulatory environment allows these adaptations to occur. In recent times, remote Australia’s “power to persuade” government to consider its needs when designing regulatory environments has diminished as a result of the changing nature of remote economies. This paper uses two case examples—that of air transport technology and that of communications technology—to demonstrate how a poor regulatory environment in effect increases the isolation of remote settlements. In the case of air transport, over regulation has made the cost of adoption and access too high for many remote dwellers. In the case of communications technology, de-regulation has made it difficult for remote dwellers to demand equity of access to infrastructure. We conclude by suggesting that regulatory systems need to be more aware of the unique conditions facing remote populations. Research into the persistently low rates of technology adoption in remote areas needs to be more cognizant of the regulatory adaptability aspect.

  11. Dealing with radon in dwellings

    International Nuclear Information System (INIS)

    Castren, O.

    1987-01-01

    A review is made of the measurements, regulatory initiatives and remedial action taken in Finland since the discovery in 1981 of the first indoor radon concentrations higher than 10,000 Bq/m 3 . The emphasis is on the results of measurements, explanations of them and their use for the rational solution of the radon problems. Localizing the high-concentration areas and dwellings has been one of the main objectives. The latest radon map is based on measurements in 8,150 dwellings in 235 localities. The geographical distribution cannot be explained only by the uranium concentration of the bedrock. The main reason for deviations is the ground permeability. The local fine structure is most notably influenced by the glacifluvial sand and grvel formations (eskers and ice-marginal formations). The highest concentrations are often caused by synergism between an elevated uranium concentration, situation on an esker and a great temperature difference between indoor and outdoor air. They are usually connected with a large seasonal variation, the concentration being at maximum during the coldest time in winter. Indoor radon distribution is compared with newly published maps on the incidence of lung cancer in Finland

  12. Practicing the Attentional Dwell Away?

    DEFF Research Database (Denmark)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus

    2007-01-01

    Studies of the time course of visual attention have identified a temporary functional blindness to the second of two spatially separated targets: attending to one visual stimulus may lead to impairments in identifying a second stimulus presented about 200-500 ms later than the first. The phenomenon...... is known as the attentional dwell time (e.g. Duncan, Ward, Shapiro, 1994). Previous studies of attentional dwell time have all used naive subjects running few (.... The results suggest that the majority of subjects may learn to optimize their performance reducing the attentional dwell time effect substantially. Further, the reduction in the attentional dwell time effect seems to be closely linked to the ability of the subject to inhibit eye movements while performing...

  13. Focused ion beam scan routine, dwell time and dose optimizations for submicrometre period planar photonic crystal components and stamps in silicon

    International Nuclear Information System (INIS)

    Hopman, Wico C L; Ay, Feridun; Hu, Wenbin; Gadgil, Vishwas J; Kuipers, Laurens; Pollnau, Markus; Ridder, Rene M de

    2007-01-01

    Focused ion beam (FIB) milling is receiving increasing attention for nanostructuring in silicon (Si). These structures can for example be used for photonic crystal structures in a silicon-on-insulator (SOI) configuration or for moulds which can have various applications in combination with imprint technologies. However, FIB fabrication of submicrometre holes having perfectly vertical sidewalls is still challenging due to the redeposition effect in Si. In this study we show how the scan routine of the ion beam can be used as a sidewall optimization parameter. The experiments have been performed in Si and SOI. Furthermore, we show that sidewall angles as small as 1.5 0 are possible in Si membranes using a spiral scan method. We investigate the effect of the dose, loop number and dwell time on the sidewall angle, interhole milling and total milling depth by studying the milling of single and multiple holes into a crystal. We show that the sidewall angles can be as small as 5 0 in (bulk) Si and SOI when applying a larger dose. Finally, we found that a relatively large dwell time of 1 ms and a small loop number is favourable for obtaining vertical sidewalls. By comparing the results with those obtained by others, we conclude that the number of loops at a fixed dose per hole is the parameter that determines the sidewall angle and not the dwell time by itself

  14. Distributed Time Synchronization Algorithms and Opinion Dynamics

    Science.gov (United States)

    Manita, Anatoly; Manita, Larisa

    2018-01-01

    We propose new deterministic and stochastic models for synchronization of clocks in nodes of distributed networks. An external accurate time server is used to ensure convergence of the node clocks to the exact time. These systems have much in common with mathematical models of opinion formation in multiagent systems. There is a direct analogy between the time server/node clocks pair in asynchronous networks and the leader/follower pair in the context of social network models.

  15. 'Universal' Distribution of Interearthquake Times Explained

    International Nuclear Information System (INIS)

    Saichev, A.; Sornette, D.

    2006-01-01

    We propose a simple theory for the 'universal' scaling law previously reported for the distributions of waiting times between earthquakes. It is based on a largely used benchmark model of seismicity, which just assumes no difference in the physics of foreshocks, mainshocks, and aftershocks. Our theoretical calculations provide good fits to the data and show that universality is only approximate. We conclude that the distributions of interevent times do not reveal more information than what is already known from the Gutenberg-Richter and the Omori power laws. Our results reinforce the view that triggering earthquakes by other earthquakes is a key physical mechanism to understand seismicity

  16. Linking age, survival, and transit time distributions

    Science.gov (United States)

    Calabrese, Salvatore; Porporato, Amilcare

    2015-10-01

    Although the concepts of age, survival, and transit time have been widely used in many fields, including population dynamics, chemical engineering, and hydrology, a comprehensive mathematical framework is still missing. Here we discuss several relationships among these quantities by starting from the evolution equation for the joint distribution of age and survival, from which the equations for age and survival time readily follow. It also becomes apparent how the statistical dependence between age and survival is directly related to either the age dependence of the loss function or the survival-time dependence of the input function. The solution of the joint distribution equation also allows us to obtain the relationships between the age at exit (or death) and the survival time at input (or birth), as well as to stress the symmetries of the various distributions under time reversal. The transit time is then obtained as a sum of the age and survival time, and its properties are discussed along with the general relationships between their mean values. The special case of steady state case is analyzed in detail. Some examples, inspired by hydrologic applications, are presented to illustrate the theory with the specific results. This article was corrected on 11 Nov 2015. See the end of the full text for details.

  17. Profiling Occupant Behaviour in Danish Dwellings using Time Use Survey Data - Part II: Time-related Factors and Occupancy

    DEFF Research Database (Denmark)

    Barthelmes, V.M.; Li, R.; Andersen, R.K.

    2018-01-01

    Occupant behaviour has been shown to be one of the key driving factors of uncertainty in prediction of energy consumption in buildings. Building occupants affect building energy use directly and indirectly by interacting with building energy systems such as adjusting temperature set...... occupant profiles for prediction of energy use to reduce the gap between predicted and real building energy consumptions. In this study, we exploit diary-based Danish Time Use Surveys for understanding and modelling occupant behaviour in the residential sector in Denmark. This paper is a continuation......-points, switching lights on/off, using electrical devices and opening/closing windows. Furthermore, building inhabitants’ daily activity profiles clearly shape the timing of energy demand in households. Modelling energy-related human activities throughout the day, therefore, is crucial to defining more realistic...

  18. Timed Up and Go test, atrophy of medial temporal areas and cognitive functions in community-dwelling older adults with normal cognition and mild cognitive impairment.

    Science.gov (United States)

    Kose, Yujiro; Ikenaga, Masahiro; Yamada, Yosuke; Morimura, Kazuhiro; Takeda, Noriko; Ouma, Shinji; Tsuboi, Yoshio; Yamada, Tatsuo; Kimura, Misaka; Kiyonaga, Akira; Higaki, Yasuki; Tanaka, Hiroaki

    2016-12-01

    This study aimed to ascertain if performance on the Timed Up and Go (TUG) test is associated with indicators of brain volume and cognitive functions among community-dwelling older adults with normal cognition or mild cognitive impairment. Participants were 80 community-dwelling older adults aged 65-89years (44 men, 36 women), including 20 with mild cognitive impairment. Participants completed the TUG and a battery of cognitive assessments, including the Mini-Mental State Examination (MMSE), the Logical Memory I and II (LM-I, LM-II) subtests of the Wechsler Memory Scale-Revised; and the Trail Making Test A and B (TMT-A, TMT-B). Bilateral, right- and left-side medial temporal area atrophy as well as whole gray and white matter indices were determined with the Voxel-based Specific Regional Analysis System for Alzheimer's Disease. We divided participants into three groups based on TUG performance: "better" (≤6.9s); "normal" (7-10s); and "poor" (≥10.1s). Worse TMT-A and TMT-B performance showed significant independent associations with worse TUG performance (Pareas were significantly independently associated with worse TUG performance (Parea atrophy in community-dwelling older adults. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Implementing Run-Time Evaluation of Distributed Timing Constraints in a Real-Time Environment

    DEFF Research Database (Denmark)

    Kristensen, C. H.; Drejer, N.

    1994-01-01

    In this paper we describe a solution to the problem of implementing run-time evaluation of timing constraints in distributed real-time environments......In this paper we describe a solution to the problem of implementing run-time evaluation of timing constraints in distributed real-time environments...

  20. Time coded distribution via broadcasting stations

    Science.gov (United States)

    Leschiutta, S.; Pettiti, V.; Detoma, E.

    1979-01-01

    The distribution of standard time signals via AM and FM broadcasting stations presents the distinct advantages to offer a wide area coverage and to allow the use of inexpensive receivers, but the signals are radiated a limited number of times per day, are not usually available during the night, and no full and automatic synchronization of a remote clock is possible. As an attempt to overcome some of these problems, a time coded signal with a complete date information is diffused by the IEN via the national broadcasting networks in Italy. These signals are radiated by some 120 AM and about 3000 FM and TV transmitters around the country. In such a way, a time ordered system with an accuracy of a couple of milliseconds is easily achieved.

  1. Asymptotic Time Averages and Frequency Distributions

    Directory of Open Access Journals (Sweden)

    Muhammad El-Taha

    2016-01-01

    Full Text Available Consider an arbitrary nonnegative deterministic process (in a stochastic setting {X(t,  t≥0} is a fixed realization, i.e., sample-path of the underlying stochastic process with state space S=(-∞,∞. Using a sample-path approach, we give necessary and sufficient conditions for the long-run time average of a measurable function of process to be equal to the expectation taken with respect to the same measurable function of its long-run frequency distribution. The results are further extended to allow unrestricted parameter (time space. Examples are provided to show that our condition is not superfluous and that it is weaker than uniform integrability. The case of discrete-time processes is also considered. The relationship to previously known sufficient conditions, usually given in stochastic settings, will also be discussed. Our approach is applied to regenerative processes and an extension of a well-known result is given. For researchers interested in sample-path analysis, our results will give them the choice to work with the time average of a process or its frequency distribution function and go back and forth between the two under a mild condition.

  2. SU-E-T-16: A Comparison of Expected Dwell Times and Dose Variations for NAMD Patients Treated with An Episcleral Brachytherapy Device

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, R [Univ Arizona, Tucson, AZ (United States); Patel, P; Balaggan, K; Restori, M; Ilginis, T [Moorfields Eye Hospital, London (United Kingdom); Drew, M; McGovern, M; Vitali, J; Marsteller, L [Salutaris Medical Devices, Inc., Tucson, AZ (United States)

    2015-06-15

    Purpose: To evaluate the variations in dwell times and doses expected when using an episcleral brachytherapy device for treatment of neovascular agerelated macular degeneration (n-AMD) based on accurate imaging modalities Methods: Data from 40 eyes from 40 subjects with known n- AMD acquired through the Distance of Choroid Study (DOCS) conducted at Moorfields Eye Hospital was used to determine the target depth; the distance from the outer scleral surface of the eye, through the choroid, to the apex of the choroidal neovascularization (CNV). Each subject underwent, in triplicate, enhanced-depth Spectral Domain Optical Coherence Tomography (SD-OCT), Swept Source Optical Coherence Tomography, (SS-OCT) and Ocular Ultrasound (O-US). These data are the most comprehensive and accurate measurements of the dimensions of the CNV and adjacent layers of the eye for this cohort of patients. During treatment of n-AMD, patients receive a dose of 24Gy to the apex at the target depth. Using the percentage depth dose for a Sr-90 episcleral brachytherapy device, dwell times and doses to the apex were computed to determine the expected variations. Results: The mean target depth and the 95% confidence interval (CI) determined by combining O-US with SD-OCT were 1326 (956,1696)µm and with SS-OCT were 1332 (970,1693)µm. The calculated corresponding mean dwell times and 95% (CI) were 334 (223,445)s and 335 (226,445)s for SD-OCT and SS-OCT determined depths, respectively. The corresponding mean apex dose and 95% (CI) were 24 (35.9,18.0)Gy (SD-OCT) and 24 (35.6,18.1)Gy (SS-OCT). Conclusion: For episcleral brachytherapy treatment of n-AMD, using a patient population average target depth for treatment planning is inadequate, resulting in dose variations of a factor of approximately two over the 95% CI and larger variations for a nontrivial segment of the population. Each patient should have individualized imaging studies to determine the target depth for use in the dwell time calculation

  3. An Abnormal Increase of Fatigue Life with Dwell Time during Creep-Fatigue Deformation for Directionally Solidified Ni-Based Superalloy DZ445

    Science.gov (United States)

    Ding, Biao; Ren, Weili; Deng, Kang; Li, Haitao; Liang, Yongchun

    2018-03-01

    The paper investigated the creep-fatigue behavior for directionally solidified nickel-based superalloy DZ445 at 900 °C. It is found that the fatigue life shows an abnormal increase when the dwell time exceeds a critical value during creep-fatigue deformation. The area of hysteresis loop and fractograph explain the phenomenon quite well. The shortest life corresponds to the maximal area of hysteresis loop, i. e. the maximum energy to be consumed during the creep-fatigue cycle. The fractographic observation of failed samples further supports the abnormal behavior of fatigue life.

  4. SU-E-T-16: A Comparison of Expected Dwell Times and Dose Variations for NAMD Patients Treated with An Episcleral Brachytherapy Device

    International Nuclear Information System (INIS)

    Hamilton, R; Patel, P; Balaggan, K; Restori, M; Ilginis, T; Drew, M; McGovern, M; Vitali, J; Marsteller, L

    2015-01-01

    Purpose: To evaluate the variations in dwell times and doses expected when using an episcleral brachytherapy device for treatment of neovascular agerelated macular degeneration (n-AMD) based on accurate imaging modalities Methods: Data from 40 eyes from 40 subjects with known n- AMD acquired through the Distance of Choroid Study (DOCS) conducted at Moorfields Eye Hospital was used to determine the target depth; the distance from the outer scleral surface of the eye, through the choroid, to the apex of the choroidal neovascularization (CNV). Each subject underwent, in triplicate, enhanced-depth Spectral Domain Optical Coherence Tomography (SD-OCT), Swept Source Optical Coherence Tomography, (SS-OCT) and Ocular Ultrasound (O-US). These data are the most comprehensive and accurate measurements of the dimensions of the CNV and adjacent layers of the eye for this cohort of patients. During treatment of n-AMD, patients receive a dose of 24Gy to the apex at the target depth. Using the percentage depth dose for a Sr-90 episcleral brachytherapy device, dwell times and doses to the apex were computed to determine the expected variations. Results: The mean target depth and the 95% confidence interval (CI) determined by combining O-US with SD-OCT were 1326 (956,1696)µm and with SS-OCT were 1332 (970,1693)µm. The calculated corresponding mean dwell times and 95% (CI) were 334 (223,445)s and 335 (226,445)s for SD-OCT and SS-OCT determined depths, respectively. The corresponding mean apex dose and 95% (CI) were 24 (35.9,18.0)Gy (SD-OCT) and 24 (35.6,18.1)Gy (SS-OCT). Conclusion: For episcleral brachytherapy treatment of n-AMD, using a patient population average target depth for treatment planning is inadequate, resulting in dose variations of a factor of approximately two over the 95% CI and larger variations for a nontrivial segment of the population. Each patient should have individualized imaging studies to determine the target depth for use in the dwell time calculation

  5. Low frequency sounds in dwellings : A case control study

    NARCIS (Netherlands)

    van den Berg, Frits (G P)

    2000-01-01

    The purpose of this study is to systematically assess the level and spectral distribution of low frequency (LF) sounds in dwellings. Measurements of broad and narrow hand sound levels have been made in 36 Dutch dwellings in 1998. In 19 dwellings there were complaints about LF noise, in 17 others no

  6. Time Optimal Run-time Evaluation of Distributed Timing Constraints in Process Control Software

    DEFF Research Database (Denmark)

    Drejer, N.; Kristensen, C.H.

    1993-01-01

    This paper considers run-time evaluation of an important class of constraints; Timing constraints. These appear extensively in process control systems. Timing constraints are considered in distributed systems, i.e. systems consisting of multiple autonomous nodes......

  7. A distributed real-time operating system

    International Nuclear Information System (INIS)

    Tuynman, F.; Hertzberger, L.O.

    1984-07-01

    A distributed real-time operating system, Fados, has been developed for an embedded multi-processor system. The operating system is based on a host target approach and provides for communication between arbitrary processes on host and target machine. The facilities offered are, apart from process communication, access to the file system on the host by programs on the target machine and monitoring and debugging of programs on the target machine from the host. The process communication has been designed in such a way that the possibilities are the same as those offered by the Ada programming language. The operating system is implemented on a MC 68000 based multiprocessor system in combination with a Unix host. (orig.)

  8. Protein Intake and Distribution in Relation to Physical Functioning and Quality of Life in Community-Dwelling Elderly People: Acknowledging the Role of Physical Activity

    Directory of Open Access Journals (Sweden)

    Dominique S. M. ten Haaf

    2018-04-01

    Full Text Available Increasing total protein intake and a spread protein intake distribution are potential strategies to attenuate sarcopenia related loss of physical function and quality of life. The aim of this cross-sectional study was to investigate whether protein intake and protein intake distribution are associated with muscle strength, physical function and quality of life in community-dwelling elderly people with a wide range of physical activity. Dietary and physical activity data were obtained from two studies (N = 140, age 81 ± 6, 64% male, with the following outcome measures: physical functioning (Short Physical Performance Battery (SPPB, comprising balance, gait speed and chair rise tests, handgrip strength and quality of life (EQ-5D-5L. Protein intake distribution was calculated for each participant as a coefficient of variance (CV = SD of grams of protein intake per main meal divided by the average total amount of proteins (grams of the main meals. Based on the CV, participants were divided into tertiles and classified as spread, intermediate or pulse. The average total protein intake was 1.08 ± 0.29 g/kg/day. Total protein intake was not associated with outcome measures using multivariate regression analyses. Individuals with a spread protein diet during the main meals (CV < 0.43 had higher gait speed compared to those with an intermediate diet (CV 0.43–0.62 (β = −0.42, p = 0.035, whereas a spread and pulse protein diet were not associated with SPPB total score, chair rise, grip strength and Quality-Adjusted Life Year (QALY. The interaction of higher physical activity and higher total protein intake was significantly associated with higher quality of life (β = 0.71, p = 0.049. While this interaction was not associated with SPPB or grip strength, the association with quality of life emphasizes the need for a higher total protein intake together with an active lifestyle in the elderly.

  9. Effect of a dual task on quantitative Timed Up and Go performance in community-dwelling older adults: A preliminary study.

    Science.gov (United States)

    Smith, Erin; Walsh, Lorcan; Doyle, Julie; Greene, Barry; Blake, Catherine

    2017-08-01

    The Timed Up and Go test (TUG) is used as a measure of functional ability in older adults; however, the method of measurement does not allow us to determine which aspects of the test deficits occur in. The aim of the present study was to examine the ability of the quantitative TUG (QTUG) to measure performance during the TUG test under three different conditions - single task, motor task and cognitive dual task - and to compare performance between fallers and non-fallers in high-functioning community-dwelling older adults. A total of 37 community-dwelling older adults, 16 with a self-reported falls history in the previous year, were recruited. Participants underwent a falls risk assessment with a physiotherapist including the QTUG under three conditions (single task, motor task, cognitive dual-task). A total of 10 clinical parameters were chosen for analysis using mancova and a series of ancova, with age, sex and body mass index included as covariates. The mancova analysis showed a significant difference across the three task conditions (Wilk's Lambda F 20,186  = 3.37, P task and faller status (Wilk's Lambda F 20,192  = 1.131, P = 0.321) was found. ancova results for each of the parameters showed overall differences between single, motor and cognitive tasks for all of the variables, except time in double support. When faller and non-faller differences were explored, cadence and stride velocity was greater, and stride time longer in those with a prior history of falls. In community-dwelling older adults, these preliminary results show that a cognitive dual-task significantly (P performance in almost all parameters, with a significant (P task. Although no statistical difference was found between fallers and non-fallers for many of the parameters, cadence, stride time and stride velocity were statistically different (P performance under dual-task conditions between fallers and non-fallers in this population, and to look at the ability of dual

  10. Late endovascular removal of Günther-Tulip inferior vena cava filter and stent reconstruction of chronic post-thrombotic iliocaval obstruction after 4753 days of filter dwell time: a case report with review of literature.

    Science.gov (United States)

    Doshi, Mehul Harshad; Narayanan, Govindarajan

    2016-12-01

    Chronic post-thrombotic obstruction of the inferior vena cava (IVC) or iliocaval junction is an uncommon complication of long indwelling IVC filter. When such an obstruction is symptomatic, endovascular treatment options include stent placement with or without filter retrieval. Filter retrieval becomes increasingly difficult with longer dwell times. We present a case of symptomatic post-thrombotic obstruction of the iliocaval junction related to Günther-Tulip IVC filter (Cook Medical Inc, Bloomington, IN) with dwell time of 4753 days, treated successfully with endovascular filter removal and stent reconstruction. Filter retrieval and stent reconstruction may be a treatment option in symptomatic patients with filter-related chronic IVC or iliocaval junction obstruction, even after prolonged dwell time.

  11. Association of sitting time and breaks in sitting with muscle mass, strength, function, and inflammation in community-dwelling older adults.

    Science.gov (United States)

    Reid, N; Healy, G N; Gianoudis, J; Formica, M; Gardiner, P A; Eakin, E E; Nowson, C A; Daly, R M

    2018-02-26

    The mechanisms through which excessive sitting time impacts health are important to understand. This study found that each hour of sitting per day was not associated with physical function, although associations with poor body composition were observed. Reducing sitting time for improved weight management in older adults needs further exploration. To examine the association of sitting time and breaks in sitting time with muscle mass, strength, function, and inflammation in older Australians. Data from the thigh-worn activPAL3™ monitor (7-day continuous wear) was used to derive time spent sitting (hours) and total number of sit-stand transitions per day. Body composition (dual energy X-ray absorptiometry), lower-body muscle strength, function (timed up-and-go [TUG], 4-m gait speed, four square step test, 30-second sit-to-stand), and serum inflammatory markers (interleukin-[IL-6], IL-8, IL-10, tumor necrosis factor-alpha [TNF-α], and adiponectin) were measured. Multiple regression analyses, adjusted for age, sex, ethnicity, education, employment status, marital status, number of prescription medications, smoking status, vitamin D, and stepping time, were used to assess the associations. Data from 123 community-dwelling older adults (aged 65-84 years, 63% female) were used. Total daily sitting time was associated with lower percentage lean mass (β [95%CI], - 1.70% [- 2.30, - 1.10]) and higher total body fat mass (2.92 kg [1.94, 3.30]). More frequent breaks in sitting time were associated with a 45% reduced risk of having pre-sarcopenia (OR = 0.55; 95% CI 0.34, 0.91; model 1), defined as appendicular lean mass divided by BMI. No significant associations were observed for sitting time or breaks in sitting with measures of muscle strength, function, or inflammation. In older community-dwelling adults, greater sitting time was associated with a lower percentage lean mass, while more frequent breaks in sitting time were associated with lower odds of having

  12. Time-dependent radioactivity distribution in MAFF

    International Nuclear Information System (INIS)

    Nebel, F.; Zech, E.; Faestermann, T.; Kruecken, R.; Maier-Komor, P.; Assmann, W.; Szerypo, J.; Gross, M.; Kester, O.; Thirolf, P.G.; Groetzschel, R.

    2006-01-01

    The Munich Accelerator for Fission Fragments is planned to be installed at the FRM II in Garching. It will operate a uranium-carbide-loaded graphite matrix as a target for neutron-induced fission. The radioactive reaction fragments leave the ion source as both, atoms and ions. For radiation safety it is imperative to have a basic understanding of the fragment distribution within the beam line. Atoms leaving the graphite matrix will spread like a gas and stick to surfaces depending on their species. A probabilistic Monte-Carlo approach is used to predict the surface coating of internal surfaces of the beam line for all fission nuclides. To decrease calculation time, the problem is reduced to two dimensions with the surface areas being a measure for the probability, that they are hit by a particle. The program is completely time dependent to implement radioactive decay. Ions leaving the fission ion source are transported by electrostatic means towards the mass pre-separator, a low-resolution dipole magnet with a complex slit system in the focal plane. All unwanted ions are stopped at the slits, resulting in a high level of radioactive contamination. While it is advantageous for shielding purposes to have the majority of the contamination in one point, precautions must be taken to ensure that it stays that way. Material corrosion caused by sputtering will release previously implanted radionuclides. To reduce this effect, different methods are under investigation, one of which is changing the slit geometry. The considered designs will be described and experimental results will be shown

  13. 24 CFR 203.38 - Location of dwelling.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Location of dwelling. 203.38... § 203.38 Location of dwelling. At the time a mortgage is insured there must be located on the mortgaged property one or more dwellings designed principally for residential use for not more than four families...

  14. Time evolution of distribution functions in dissipative environments

    International Nuclear Information System (INIS)

    Hu Li-Yun; Chen Fei; Wang Zi-Sheng; Fan Hong-Yi

    2011-01-01

    By introducing the thermal entangled state representation, we investigate the time evolution of distribution functions in the dissipative channels by bridging the relation between the initial distribution function and the any time distribution function. We find that most of them are expressed as such integrations over the Laguerre—Gaussian function. Furthermore, as applications, we derive the time evolution of photon-counting distribution by bridging the relation between the initial distribution function and the any time photon-counting distribution, and the time evolution of R-function characteristic of nonclassicality depth. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  15. Solar low energy dwellings

    International Nuclear Information System (INIS)

    Hestnes, Anne Grete

    2000-01-01

    By now, a lot has been learnt about how to reduce energy use in dwellings using solar and low energy technologies, and many good examples can be found throughout Europe. Still, they are not quite the common feature we would expect them to be, i.e. they have not really penetrated the market. The reason for this is in part a result of the fact that the designers and developers of these buildings have not looked at what the market wants and needs, but rather at how to use a set of given technologies. The buildings are the result of a technology push rather than a market pull and have therefore, often, been detached or semidetached dwellings with different solar technologies added on in less than optimal ways. In order to increase market penetration, it is time to look at the market trends and relate to these. Fortunately, quite a few European architects have realized this and have started designing somewhat different residential buildings. The paper focuses on examples of the new trends in solar residential architecture and by that, hopefully, it shows that we are on the right track. (au)

  16. Distributed Real-Time Embedded Video Processing

    National Research Council Canada - National Science Library

    Lv, Tiehan

    2004-01-01

    .... A deployable multi-camera video system must perform distributed computation, including computation near the camera as well as remote computations, in order to meet performance and power requirements...

  17. Migrating to a real-time distributed parallel simulator architecture

    CSIR Research Space (South Africa)

    Duvenhage, B

    2007-07-01

    Full Text Available A legacy non-distributed logical time simulator is migrated to a distributed architecture to parallelise execution. The existing Discrete Time System Specification (DTSS) modelling formalism is retained to simplify the reuse of existing models...

  18. Time Distribution Capabilities of the Wide Area Augmentation System (WAAS)

    National Research Council Canada - National Science Library

    Klepczynski, William J; Fenton, Pat; Powers, Ed

    2001-01-01

    ...), the FAA has been interested in developing the use of the WAAS for time distribution. An economical, evolutionary approach to the development of the WAAS for time distribution has been pursued...

  19. Associations between Perceived Neighborhood Walkability and Walking Time, Wellbeing, and Loneliness in Community-Dwelling Older Chinese People in Hong Kong.

    Science.gov (United States)

    Yu, Ruby; Cheung, Osbert; Lau, Kevin; Woo, Jean

    2017-10-09

    This study examined the cross-sectional associations between perceived neighborhood walkability and walking time, physical activity, wellbeing, and loneliness, and examined which components of walkability were most strongly associated with better wellbeing and less loneliness in older adults. Participants were community-dwelling Chinese adults aged 60+ ( n = 181). Walkability was measured using nine items selected from the Chinese version of the abbreviated Neighborhood Environment Walkability Scales (NEWS) and NEWS for Chinese Seniors. Outcomes were walking time, physical activity, wellbeing (life satisfaction, happiness, sense of purpose and meaning in life), and loneliness. The mean age of the participants was 71.7 ± 7.8 years. Walkability was positively associated with walking time ( p = 0.001, p for trend walkable had higher scores for life satisfaction ( p = 0.002) and happiness ( p = 0.002), and lower scores for loneliness ( p = 0.019), compared with those who perceived their neighborhoods as less walkable. However, perceived neighborhood walkability was not associated with sense of purpose and meaning in life. Among components of walkability, land use mix-access, infrastructure and safety for walking, and traffic safety showed the strongest associations with the measures of wellbeing. The results of this study support the importance of neighborhood walkability for health behavior and wellbeing of older adults. The wellbeing of older adults may be enhanced through the improvement of land use mix-access, infrastructure for walking, and traffic safety.

  20. Same Hours, Different Time Distribution: Any Difference in EFL?

    Science.gov (United States)

    Serrano, Raquel; Munoz, Carmen

    2007-01-01

    The effects of the distribution of instructional time on the acquisition of a second or foreign language are still not well known. This paper will analyze the performance of adult students enrolled in three different types of EFL programs in which the distribution of time varies. The first one, called "extensive", distributes a total of 110 h in 7…

  1. Situations of dwelling

    DEFF Research Database (Denmark)

    Welling, Helen; Duelund Mortensen, Peder; Wiell Nordberg, Lene

    2006-01-01

    This article explores changeable dwellings that offer the possibility of satisfying spontaneous activities and needs arising from today's changing family patterns. It deals with dwellings that provide people with room for development and flexibility - an open framework, which can be adapted to new...

  2. A Distributed Representation of Remembered Time

    Science.gov (United States)

    2015-11-19

    As illustrated in Fig. 3a, during intact neurotransmission , plateau potentials that sustained stable firing could either be induced by transiently...time they are experienced. Suppose we want to predict what stimulus will occur 10 s into the future. If we had access to the future state of the...timeline, we could determine what will happen at that future time using simple association. The method for estimating the future proceeds by translating the

  3. Design a Fault Tolerance for Real Time Distributed System

    OpenAIRE

    Ban M. Khammas

    2012-01-01

    This paper designed a fault tolerance for soft real time distributed system (FTRTDS). This system is designed to be independently on specific mechanisms and facilities of the underlying real time distributed system. It is designed to be distributed on all the computers in the distributed system and controlled by a central unit.Besides gathering information about a target program spontaneously, it provides information about the target operating system and the target hardware in order to diagno...

  4. Calculation of the ortho–para conversion of hydrogen in a p–type silicon lattice using a dwell time approach

    International Nuclear Information System (INIS)

    Herman, R M; Suarez, A; Sofo, J; Lewis, J C

    2012-01-01

    Quantitative spectroscopic studies of hydrogen in a p–type silicon lattice at room temperature and at reduced temperature have led to rates for the ortho-para conversion process. The characteristic relaxation time at room temperature is about 8 hours. Explanations of this rate on the basis of the interaction between the interstitial H 2 and naturally occurring 29 Si using the Wigner rate expression encounter several difficulties, the principal being that the decay would involve multiexponential decay, in contradiction to observation. In an earlier work we calculated the rate assuming that the ortho–para conversion was effected during scattering of holes from the hydrogen molecules. The result was smaller than observed by several orders of magnitude. In the present work it is assumed that sp z holes diffuse randomly throughout the Si lattice, dwelling on effective areas associated with sp z sites. The transition matrix elements are the same as for the scattering mechanism. The resultant characteristic time at room temperature we find to be 1000 hr. Considering the uncertainties in the calculation the discrepancy between our result and observation is not sufficient as to negate our physical picture.

  5. Robust iterative learning control for multi-phase batch processes: an average dwell-time method with 2D convergence indexes

    Science.gov (United States)

    Wang, Limin; Shen, Yiteng; Yu, Jingxian; Li, Ping; Zhang, Ridong; Gao, Furong

    2018-01-01

    In order to cope with system disturbances in multi-phase batch processes with different dimensions, a hybrid robust control scheme of iterative learning control combined with feedback control is proposed in this paper. First, with a hybrid iterative learning control law designed by introducing the state error, the tracking error and the extended information, the multi-phase batch process is converted into a two-dimensional Fornasini-Marchesini (2D-FM) switched system with different dimensions. Second, a switching signal is designed using the average dwell-time method integrated with the related switching conditions to give sufficient conditions ensuring stable running for the system. Finally, the minimum running time of the subsystems and the control law gains are calculated by solving the linear matrix inequalities. Meanwhile, a compound 2D controller with robust performance is obtained, which includes a robust extended feedback control for ensuring the steady-state tracking error to converge rapidly. The application on an injection molding process displays the effectiveness and superiority of the proposed strategy.

  6. Real time computer system with distributed microprocessors

    International Nuclear Information System (INIS)

    Heger, D.; Steusloff, H.; Syrbe, M.

    1979-01-01

    The usual centralized structure of computer systems, especially of process computer systems, cannot sufficiently use the progress of very large-scale integrated semiconductor technology with respect to increasing the reliability and performance and to decreasing the expenses especially of the external periphery. This and the increasing demands on process control systems has led the authors to generally examine the structure of such systems and to adapt it to the new surroundings. Computer systems with distributed, optical fibre-coupled microprocessors allow a very favourable problem-solving with decentralized controlled buslines and functional redundancy with automatic fault diagnosis and reconfiguration. A fit programming system supports these hardware properties: PEARL for multicomputer systems, dynamic loader, processor and network operating system. The necessary design principles for this are proved mainly theoretically and by value analysis. An optimal overall system of this new generation of process control systems was established, supported by results of 2 PDV projects (modular operating systems, input/output colour screen system as control panel), for the purpose of testing by apllying the system for the control of 28 pit furnaces of a steel work. (orig.) [de

  7. Predictive Cutoff Values of the Five-Times Sit-to-Stand Test and the Timed "Up & Go" Test for Disability Incidence in Older People Dwelling in the Community.

    Science.gov (United States)

    Makizako, Hyuma; Shimada, Hiroyuki; Doi, Takehiko; Tsutsumimoto, Kota; Nakakubo, Sho; Hotta, Ryo; Suzuki, Takao

    2017-04-01

    Lower extremity functioning is important for maintaining activity in elderly people. Optimal cutoff points for standard measurements of lower extremity functioning would help identify elderly people who are not disabled but have a high risk of developing disability. The purposes of this study were: (1) to determine the optimal cutoff points of the Five-Times Sit-to-Stand Test and the Timed "Up & Go" Test for predicting the development of disability and (2) to examine the impact of poor performance on both tests on the prediction of the risk of disability in elderly people dwelling in the community. This was a prospective cohort study. A population of 4,335 elderly people dwelling in the community (mean age = 71.7 years; 51.6% women) participated in baseline assessments. Participants were monitored for 2 years for the development of disability. During the 2-year follow-up period, 161 participants (3.7%) developed disability. The optimal cutoff points of the Five-Times Sit-to-Stand Test and the Timed "Up & Go" Test for predicting the development of disability were greater than or equal to 10 seconds and greater than or equal to 9 seconds, respectively. Participants with poor performance on the Five-Times Sit-to-Stand Test (hazard ratio = 1.88; 95% CI = 1.11-3.20), the Timed "Up & Go" Test (hazard ratio = 2.24; 95% CI = 1.42-3.53), or both tests (hazard ratio = 2.78; 95% CI = 1.78-4.33) at the baseline assessment had a significantly higher risk of developing disability than participants who had better lower extremity functioning. All participants had good initial functioning and participated in assessments on their own. Causes of disability were not assessed. Assessments of lower extremity functioning with the Five-Times Sit-to-Stand Test and the Timed "Up & Go" Test, especially poor performance on both tests, were good predictors of future disability in elderly people dwelling in the community. © 2017 American Physical Therapy Association

  8. Profiling Occupant Behaviour in Danish Dwellings using Time Use Survey Data - Part I: Data Description and Activity Profiling

    DEFF Research Database (Denmark)

    Barthelmes, V.M.; Li, R.; Andersen, R.K.

    2018-01-01

    Occupant behaviour has been shown to be one of the key driving factors of uncertainty in prediction of energy consumption in buildings. Building occupants affect building energy use directly and indirectly by interacting with building energy systems such as adjusting temperature set...... occupant profiles for prediction of energy use to reduce the gap between predicted and real building energy consumptions. To generate accurate occupant profiles for the residential sector in Denmark, the Danish time use surveys are considered an essential data source. The latest Danish diarybased time use......-points, switching lights on/off, using electrical devices and opening/closing windows. Furthermore, building inhabitants’ daily activity profiles clearly shape the timing of energy demand in households. Modelling energy-related human activities throughout the day, therefore, is crucial to defining more realistic...

  9. The reliability of the quantitative timed up and go test (QTUG) measured over five consecutive days under single and dual-task conditions in community dwelling older adults.

    Science.gov (United States)

    Smith, Erin; Walsh, Lorcan; Doyle, Julie; Greene, Barry; Blake, Catherine

    2016-01-01

    The timed up and go (TUG) test is a commonly used assessment in older people with variations including the addition of a motor or cognitive dual-task, however in high functioning older adults it is more difficult to assess change. The quantified TUG (QTUG) uses inertial sensors to detect test and gait parameters during the test. If it is to be used in the longitudinal assessment of older adults, it is important that we know which parameters are reliable and under which conditions. This study aims to examine the relative reliability of the QTUG over five consecutive days under single, motor and cognitive dual-task conditions. Twelve community dwelling older adults (10 females, mean age 74.17 (3.88)) performed the QTUG under three conditions for five consecutive days. The relative reliability of each of the gait parameters was assessed using intra-class correlation coefficient (ICC 3,1) and standard error of measurement (SEM). Five of the measures demonstrated excellent reliability (ICC>0.70) under all three conditions (time to complete test, walk time, number of gait cycles, number of steps and return from turn time). Measures of variability and turn derived parameters demonstrated weak reliability under all three conditions (ICC=0.05-0.49). For the most reliable parameters under single-task conditions, the addition of a cognitive task resulted in a reduction in reliability suggesting caution when interpreting results under these conditions. Certain sensor derived parameters during the QTUG test may provide an additional resource in the longitudinal assessment of older people and earlier identification of falls risk. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Acoustic classification of dwellings

    DEFF Research Database (Denmark)

    Berardi, Umberto; Rasmussen, Birgit

    2014-01-01

    insulation performance, national schemes for sound classification of dwellings have been developed in several European countries. These schemes define acoustic classes according to different levels of sound insulation. Due to the lack of coordination among countries, a significant diversity in terms...... exchanging experiences about constructions fulfilling different classes, reducing trade barriers, and finally increasing the sound insulation of dwellings.......Schemes for the classification of dwellings according to different building performances have been proposed in the last years worldwide. The general idea behind these schemes relates to the positive impact a higher label, and thus a better performance, should have. In particular, focusing on sound...

  11. On the applicability of short time measurements to the determination of annual average of radon concentration in dwelling

    International Nuclear Information System (INIS)

    Loskiewicz, J.; Olko, P.; Swakon, J.; Bogacz, J.; Janik, M.; Mazur, D.; Mazur, J.

    1998-01-01

    The variation of radon concentration in some houses in the Krakow region was investigated in order to compare results obtained using various measuring techniques. It is concluded that short-term measurements should last at least 4 days to avoid errors exceeding 30%; that weather parameters and human activity during the measurement should be recorded; that measurements should be repeated several times under various weather conditions; that seasonal variation in the region should be taken into account. (A.K.)

  12. Implementering Run-time Evaluation of Distributed Timing Constraints in a Micro Kernel

    DEFF Research Database (Denmark)

    Kristensen, C.H.; Drejer, N.; Nielsen, Jens Frederik Dalsgaard

    In the present paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems......In the present paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems...

  13. The arrival time distribution of muons in extensive air showers

    International Nuclear Information System (INIS)

    Van der Walt, D.J.

    1984-01-01

    An experiment was done to investigate the lateral dependence of the muon arrival time distribution in extensive air showers at small core distances. In the present experiment the muon arrival time distribution was investigated by measuring the relative arrival times between single muons in five fast Cerenkov detectors beneath 500g/cm 2 of concrete and at an atmospheric depth of 880g/cm 2 . It is shown that, although it is not possible to determine the arrival time distribution as such, it is possible to interpret the relative arrival times between muons in terms of the differences between the order statistics of a sample drawn from the arrival time distribution. The relationship between the arrival time distribution of muons relative to the first detected muon and the muon arrival time distribution is also derived. It was found that the dispersion of the muon arrival time distribution does not increase significantly with increasing core distance between 10m and 60m from the core. A comparison with theoretical distributions obtained from model calculations for proton initiated showers indicate that 1. the mean delay of muons with respect to the first detected muon is significantly larger than that expected from the model and 2. the observed dispersion is also significantly larger than the predicted dispersion for core distances between 10m and 60m

  14. Associations between Perceived Neighborhood Walkability and Walking Time, Wellbeing, and Loneliness in Community-Dwelling Older Chinese People in Hong Kong

    Directory of Open Access Journals (Sweden)

    Ruby Yu

    2017-10-01

    Full Text Available This study examined the cross-sectional associations between perceived neighborhood walkability and walking time, physical activity, wellbeing, and loneliness, and examined which components of walkability were most strongly associated with better wellbeing and less loneliness in older adults. Participants were community-dwelling Chinese adults aged 60+ (n = 181. Walkability was measured using nine items selected from the Chinese version of the abbreviated Neighborhood Environment Walkability Scales (NEWS and NEWS for Chinese Seniors. Outcomes were walking time, physical activity, wellbeing (life satisfaction, happiness, sense of purpose and meaning in life, and loneliness. The mean age of the participants was 71.7 ± 7.8 years. Walkability was positively associated with walking time (p = 0.001, p for trend <0.001 but not with physical activity. After adjusting for socio-demographic characteristics, health conditions, lifestyle, and negative life events, those who perceived their neighborhoods as walkable had higher scores for life satisfaction (p = 0.002 and happiness (p = 0.002, and lower scores for loneliness (p = 0.019, compared with those who perceived their neighborhoods as less walkable. However, perceived neighborhood walkability was not associated with sense of purpose and meaning in life. Among components of walkability, land use mix-access, infrastructure and safety for walking, and traffic safety showed the strongest associations with the measures of wellbeing. The results of this study support the importance of neighborhood walkability for health behavior and wellbeing of older adults. The wellbeing of older adults may be enhanced through the improvement of land use mix-access, infrastructure for walking, and traffic safety.

  15. Charged fluid distribution in higher dimensional spheroidal space-time

    Indian Academy of Sciences (India)

    A general solution of Einstein field equations corresponding to a charged fluid distribution on the background of higher dimensional spheroidal space-time is obtained. The solution generates several known solutions for superdense star having spheroidal space-time geometry.

  16. Distributed energy resources scheduling considering real-time resources forecast

    DEFF Research Database (Denmark)

    Silva, M.; Sousa, T.; Ramos, S.

    2014-01-01

    grids and considering day-ahead, hour-ahead and realtime time horizons. This method considers that energy resources are managed by a VPP which establishes contracts with their owners. The full AC power flow calculation included in the model takes into account network constraints. In this paper......, distribution function errors are used to simulate variations between time horizons, and to measure the performance of the proposed methodology. A 33-bus distribution network with large number of distributed resources is used....

  17. Positions of human dwellings affect few tropical diseases near ...

    African Journals Online (AJOL)

    user

    Some factors that possibly affect tropical disease distribution was investigated in about 500 randomize human dwellings. The studied factors include wild animals, domestic animals, wild plants, cultivated plants, nature of soil, nature of water, positions of human dwellings, nature of building material and position of animal ...

  18. Response Time Analysis of Distributed Web Systems Using QPNs

    Directory of Open Access Journals (Sweden)

    Tomasz Rak

    2015-01-01

    Full Text Available A performance model is used for studying distributed Web systems. Performance evaluation is done by obtaining load test measurements. Queueing Petri Nets formalism supports modeling and performance analysis of distributed World Wide Web environments. The proposed distributed Web systems modeling and design methodology have been applied in the evaluation of several system architectures under different external loads. Furthermore, performance analysis is done to determine the system response time.

  19. Bayesian Nonparametric Model for Estimating Multistate Travel Time Distribution

    Directory of Open Access Journals (Sweden)

    Emmanuel Kidando

    2017-01-01

    Full Text Available Multistate models, that is, models with more than two distributions, are preferred over single-state probability models in modeling the distribution of travel time. Literature review indicated that the finite multistate modeling of travel time using lognormal distribution is superior to other probability functions. In this study, we extend the finite multistate lognormal model of estimating the travel time distribution to unbounded lognormal distribution. In particular, a nonparametric Dirichlet Process Mixture Model (DPMM with stick-breaking process representation was used. The strength of the DPMM is that it can choose the number of components dynamically as part of the algorithm during parameter estimation. To reduce computational complexity, the modeling process was limited to a maximum of six components. Then, the Markov Chain Monte Carlo (MCMC sampling technique was employed to estimate the parameters’ posterior distribution. Speed data from nine links of a freeway corridor, aggregated on a 5-minute basis, were used to calculate the corridor travel time. The results demonstrated that this model offers significant flexibility in modeling to account for complex mixture distributions of the travel time without specifying the number of components. The DPMM modeling further revealed that freeway travel time is characterized by multistate or single-state models depending on the inclusion of onset and offset of congestion periods.

  20. Determining prescription durations based on the parametric waiting time distribution

    DEFF Research Database (Denmark)

    Støvring, Henrik; Pottegård, Anton; Hallas, Jesper

    2016-01-01

    two-component mixture model for the waiting time distribution (WTD). The distribution component for prevalent users estimates the forward recurrence density (FRD), which is related to the distribution of time between subsequent prescription redemptions, the inter-arrival density (IAD), for users...... in continued treatment. We exploited this to estimate percentiles of the IAD by inversion of the estimated FRD and defined the duration of a prescription as the time within which 80% of current users will have presented themselves again. Statistical properties were examined in simulation studies......-Normal). When the IAD consisted of a mixture of two Log-Normal distributions, but was analyzed with a single Log-Normal distribution, relative bias did not exceed 9%. Using a Log-Normal FRD, we estimated prescription durations of 117, 91, 137, and 118 days for NSAIDs, warfarin, bendroflumethiazide...

  1. Investigating the distribution of the value of travel time savings

    DEFF Research Database (Denmark)

    Fosgerau, Mogens

    2006-01-01

    The distribution of the value of travel time savings (VTTS) is investigated employing various nonparametric techniques to a large dataset originating from a stated choice experiment. The data contain choices between a fast and more expensive alternative and a slow and less expensive alternative....... Increasing the implicit price of time leads to an increased share of respondents who decline to pay to save time. But a significant proportion of respondents, 13%, remain willing to pay to save time at the highest price of time in the design. This means that the right tail of the VTTS distribution...

  2. Gamma radiation in dwellings

    International Nuclear Information System (INIS)

    Mjoenes, L.

    1981-08-01

    A nationwide investigation has been made into the gamma radiation in Swedish dwellings. The measurements were made with small detectors containing thermoluminescent dosimeters. The detectors were sent to the selected participants by mail. 1300 dwellings were included in the investigation. In each dwelling three measurements were made: one detector was placed in the kitchen, one in the living-room and one in the bedroom. The mean annual absorbed tissue dose in dwellings in Sweden was found to be 0.65 mGy (corresponding to an exposition rate of 12 μR/h) when the contribution from cosmic radiation had been subtracted. That represents an annual collective dose of about 4000 mansieverts to the population of Sweden. From a previous investigation we have calculate the mean value for the gamma radiation in Swedish dwellings for 1950 to be 0.4 mGy/a (8μR/h). The reason for the relatively large increase in the mean value is an increased use of building materials on stone, particularly of lightweight concrete based on alum shale, from 1940 to middle 1960s. The production of this type of lightweight concrete was discontinued in 1975 and the use of other stone-based building materials has decreased. The mean value of gamma radiation in Swedish dwellings is therefore expected to decrease slowly in the future if this tendency holds. Sweden has some 3.5 million dwellings. About 10 % of them have mean values of 1 mGy/a (19 μR/h) or more, 0.2 % have 3 mGy/a (57 μR/h) or more and a couple of hundred 5 mGy/a (95 μR/h or more. The mean value for detached houses was found to be 0.43 mGy/a (8 μR/h) and for dwellings in multi-family houses 0.80 mGy/a (15 μR/h). The investigation dwellings have also been classified according to the building materials, the year of construction and the degree of urbanization of the area. (author)

  3. Waiting time distribution in M/D/1 queueing systems

    DEFF Research Database (Denmark)

    Iversen, Villy Bæk; Staalhagen, Lars

    1999-01-01

    The well-known formula for the waiting time distribution of M/D/1 queueing systems is numerically unsuitable when the load is close to 1.0 and/or the results for a large waiting time are required. An algorithm for any load and waiting time is presented, based on the state probabilities of M/D/1...

  4. Valuing travel time variability: Characteristics of the travel time distribution on an urban road

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Fukuda, Daisuke

    2012-01-01

    This paper provides a detailed empirical investigation of the distribution of travel times on an urban road for valuation of travel time variability. Our investigation is premised on the use of a theoretical model with a number of desirable properties. The definition of the value of travel time...... variability depends on certain properties of the distribution of random travel times that require empirical verification. Applying a range of nonparametric statistical techniques to data giving minute-by-minute travel times for a congested urban road over a period of five months, we show that the standardized...... travel time is roughly independent of the time of day as required by the theory. Except for the extreme right tail, a stable distribution seems to fit the data well. The travel time distributions on consecutive links seem to share a common stability parameter such that the travel time distribution...

  5. Prediction of residence time distributions in food processing machinery

    DEFF Research Database (Denmark)

    Karlson, Torben; Friis, Alan; Szabo, Peter

    1996-01-01

    The velocity field in a co-rotating disc scraped surface heat exchanger (CDHE) is calculated using a finite element method. The residence time distribution for the CDHE is then obtained by tracing particles introduced in the inlet.......The velocity field in a co-rotating disc scraped surface heat exchanger (CDHE) is calculated using a finite element method. The residence time distribution for the CDHE is then obtained by tracing particles introduced in the inlet....

  6. Timed up and go test combined with self-rated multifactorial questionnaire on falls risk and sociodemographic factors predicts falls among community-dwelling older adults better than the timed up and go test on its own.

    Science.gov (United States)

    Ibrahim, Azianah; Singh, Devinder Kaur Ajit; Shahar, Suzana; Omar, Mohd Azahadi

    2017-01-01

    Early detection of falls risk among older adults using simple tools may assist in fall prevention strategies. The aim of this study was to identify the best parameters associated with previous falls, either the timed up and go (TUG) test combined with sociodemographic factors and a self-rated multifactorial questionnaire (SRMQ) on falls risk or the TUG on its own. Falls risk was determined based on parameters associated with previous falls. This was a retrospective cohort study. The study was conducted in a community setting. The participants were 1,086 community-dwelling older adults, with mean age of 69.6±5.6 years. Participants were categorized into fallers and nonfallers based on their history of falls in the past 12 months. Participants' sociodemographic data was taken, and SRMQ consisting of five falls-related questions was administered. Participants performed the TUG test twice, and the mean was taken as the result. A total of 161 participants were categorized as fallers (14.8%). Multivariate logistic regression analysis showed that the model ( χ 2 (6)=61.0, p factors (gender, cataract/glaucoma and joint pain), as well as the SRMQ items "previous falls history" (Q1) and "worried of falls" (Q5), was more robust in terms of falls risk association compared to that with TUG on its own ( χ 2 (1)=10.3, p factors and SRMQ with TUG is more favorable as an initial falls risk screening tool among community-dwelling older adults. Subsequently, further comprehensive falls risk assessment may be performed in clinical settings to identify the specific impairments for effective management.

  7. Estimation of modal parameters using bilinear joint time frequency distributions

    Science.gov (United States)

    Roshan-Ghias, A.; Shamsollahi, M. B.; Mobed, M.; Behzad, M.

    2007-07-01

    In this paper, a new method is proposed for modal parameter estimation using time-frequency representations. Smoothed Pseudo Wigner-Ville distribution which is a member of the Cohen's class distributions is used to decouple vibration modes completely in order to study each mode separately. This distribution reduces cross-terms which are troublesome in Wigner-Ville distribution and retains the resolution as well. The method was applied to highly damped systems, and results were superior to those obtained via other conventional methods.

  8. Distributed Issues for Ada Real-Time Systems

    Science.gov (United States)

    1990-07-23

    NUMBERS Distributed Issues for Ada Real - Time Systems MDA 903-87- C- 0056 S. AUTHOR(S) Thomas E. Griest 7. PERFORMING ORGANiZATION NAME(S) AND ADORESS(ES) 8...considerations. I Adding to the problem of distributed real - time systems is the issue of maintaining a common sense of time among all of the processors...because -omeone is waiting for the final output of a very large set of computations. However in real - time systems , consistent meeting of short-term

  9. Software reliability growth models with normal failure time distributions

    International Nuclear Information System (INIS)

    Okamura, Hiroyuki; Dohi, Tadashi; Osaki, Shunji

    2013-01-01

    This paper proposes software reliability growth models (SRGM) where the software failure time follows a normal distribution. The proposed model is mathematically tractable and has sufficient ability of fitting to the software failure data. In particular, we consider the parameter estimation algorithm for the SRGM with normal distribution. The developed algorithm is based on an EM (expectation-maximization) algorithm and is quite simple for implementation as software application. Numerical experiment is devoted to investigating the fitting ability of the SRGMs with normal distribution through 16 types of failure time data collected in real software projects

  10. Sound Insulation between Dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2011-01-01

    Regulatory sound insulation requirements for dwellings exist in more than 30 countries in Europe. In some countries, requirements have existed since the 1950s. Findings from comparative studies show that sound insulation descriptors and requirements represent a high degree of diversity...... and initiate – where needed – improvement of sound insulation of new and existing dwellings in Europe to the benefit of the inhabitants and the society. A European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs...... 2009-2013. The main objectives of TU0901 are to prepare proposals for harmonized sound insulation descriptors and for a European sound classification scheme with a number of quality classes for dwellings. Findings from the studies provide input for the discussions in COST TU0901. Data collected from 24...

  11. Factors Contributing to Single- and Dual-Task Timed "Up & Go" Test Performance in Middle-Aged and Older Adults Who Are Active and Dwell in the Community.

    Science.gov (United States)

    Chen, Hui-Ya; Tang, Pei-Fang

    2016-03-01

    Dual-task Timed "Up & Go" (TUG) tests are likely to have applications different from those of a single-task TUG test and may have different contributing factors. The purpose of this study was to compare factors contributing to performance on single- and dual-task TUG tests. This investigation was a cross-sectional study. Sixty-four adults who were more than 50 years of age and dwelled in the community were recruited. Interviews and physical examinations were performed to identify potential contributors to TUG test performance. The time to complete the single-task TUG test (TUGsingle) or the dual-task TUG test, which consisted of completing the TUG test while performing a serial subtraction task (TUGcognitive) or while carrying water (TUGmanual), was measured. Age, hip extensor strength, walking speed, general mental function, and Stroop scores for word and color were significantly associated with performance on all TUG tests. Hierarchical multiple regression models, without the input of walking speed, revealed different independent factors contributing to TUGsingle performance (Mini-Mental Status Examination score, β=-0.32), TUGmanual performance (age, β=0.35), and TUGcognitive performance (Stroop word score, β=-0.40; Mini-Mental Status Examination score, β=-0.31). At least 40% of the variance in the performance on the 3 TUG tests was not explained by common clinical measures, even when the factor of walking speed was considered. However, this study successfully identified some important factors contributing to performance on different TUG tests, and other studies have reported similar findings for single-task TUG test and dual-task gait performance. Although the TUGsingle and the TUGcognitive shared general mental function as a common factor, the TUGmanual was uniquely influenced by age and the TUGcognitive was uniquely influenced by focused attention. These results suggest that both common and unique factors contribute to performance on single- and dual

  12. Real-time Trading Strategies for Proactive Distribution Company with Distributed Generation and Demand Response

    DEFF Research Database (Denmark)

    Wang, Qi

    Distributed energy resources (DERs), such as distributed generation (DG) and demand response (DR), have been recognized worldwide as valuable resources. High integration of DG and DR in the distribution network inspires a potential deregulated environment for the distribution company (DISCO...... in the presented DL market and transact with TL real-time market. A one-leader multi-follower-type bi-level model is proposed to indicate the PDISCO's trading strategies. To participate in the TL real-time market, a methodology is presented to derive continuous bidding/offering strategies for a PDISCO. A bi...

  13. The design of a real-time distributed system

    International Nuclear Information System (INIS)

    Hertzberger, L.O.; Tuynman, F.; Mullender, S.J.; Poletiek, G.; Vermeulen, J.C.; Renesse, R. van; Tanenbaum, A.S.

    1986-01-01

    In modern physics experiments an increasing number and variety of programmable processors is used. As a consequence, a software environment is needed that provides an integrated approach to development, testing and use of real-time distributed software. This contribution is based on work being done in the AMOEBA Distributed Operating System Project and the FADOS Real-Time Distributed Operating System Project. A short description of both systems is presented as an example of how basic real-time operating system services can be organized. AMOEBA is the result of fundamental research in the field of distributed operating systems, while FADOS has been designed for applications as encountered in experimental high-energy physics. (Auth.)

  14. Master Clock and Time-Signal-Distribution System

    Science.gov (United States)

    Tjoelker, Robert; Calhoun, Malcolm; Kuhnle, Paul; Sydnor, Richard; Lauf, John

    2007-01-01

    A timing system comprising an electronic master clock and a subsystem for distributing time signals from the master clock to end users is undergoing development to satisfy anticipated timing requirements of NASA s Deep Space Network (DSN) for the next 20 to 30 years. This system has a modular, flexible, expandable architecture that is easier to operate and maintain than the present frequency and timing subsystem (FTS).

  15. Radon in dwellings in Northern Ireland. 1993 review

    International Nuclear Information System (INIS)

    Green, B.; Lomas, P.; O'Riordan, M.

    1993-01-01

    Measurements of radon made in some 1500 dwellings throughout Northern Ireland by the autumn of 1993 show that the average concentration is 19 Bq m -3 with some values up to fifty times higher. Around 30 of these dwellings are above the Action Level of 200 Bq m -3 adopted by the Government. Data are presented in considerable detail and various forms. Several hundred dwellings in Northern Ireland are estimated to exceed the Action Level, most of which are in a separately designated Affected Area in the southeast. Recommendations are made to promote the discovery and remedy of dwellings above the Action Level throughout Northern Ireland. (author)

  16. Real Time Synchronization for Creativity in Distributed Innovation Teams

    DEFF Research Database (Denmark)

    Peitersen, Dennis Kjaersgaard; Dolog, Peter; Pedersen, Esben Staunsbjerg

    2009-01-01

    In this paper we introduce a synchronization approach for real time collaborative sketching for creativity in distributed innovation teams. We base our approach on reverse AJAX. This way we ensure scalable solution for real time drawing and sketching important in creativity settings....

  17. A distributed timing system for synchronizing control and data correlation

    International Nuclear Information System (INIS)

    Stettler, M.; Thuot, M.; Dalesio, L.R.; Cole, R.; Fite, C.; Slentz, G.; Warren, D.

    1992-01-01

    Synchronization is necessary in experimental physics machines to provide positive control over related events. The Ground Test Accelerator (GTA) timing system provides this function through a distributed control system, known as the Experimental Physics and Industrial Control System (EPICS). The EPICS timing system was designed to take advantage of a distributed architecture, and provides time stamping for synchronous data correlation as well as event control. The system has been successfully demonstrated on over a dozen controller nodes for operation and data analysis. The design of the hardware, software, and operational results are discussed. (author). 2 refs., 4 figs

  18. A Distributed Computing Network for Real-Time Systems.

    Science.gov (United States)

    1980-11-03

    7 ) AU2 o NAVA TUNDEWATER SY$TEMS CENTER NEWPORT RI F/G 9/2 UIS RIBUT E 0 COMPUTIN G N LTWORK FOR REAL - TIME SYSTEMS .(U) UASSIFIED NOV Al 6 1...MORAIS - UT 92 dLEVEL c A Distributed Computing Network for Real - Time Systems . 11 𔃺-1 Gordon E/Morson I7 y tm- ,r - t "en t As J 2 -p .. - 7 I’ cNaval...NUMBER TD 5932 / N 4. TITLE mand SubotI. S. TYPE OF REPORT & PERIOD COVERED A DISTRIBUTED COMPUTING NETWORK FOR REAL - TIME SYSTEMS 6. PERFORMING ORG

  19. A distributed timing system for sychronizing control and data correlation

    International Nuclear Information System (INIS)

    Stettler, M.; Thout, M.; Dalesio, L.R.; Cole, R.; Fite, C.; Slentz, G.; Warren, D.

    1992-01-01

    Synchronization is necessary in experimental physics machines to provide positive control over related events. The Ground Test Accelerator (GTA) timing system provides this function through a distributed control system, known as the Experimental Physics and Industrial Control System (EPICS). The EPICS timing system was designed to take advantage of a distributed architecture, and provides time stamping for synchronous data correlation as well as event control. The system has been successfully demonstrated on over a dozen controller nodes for operation and data analysis. The design of the hardware, software, and operational results are discussed

  20. Distribution of tunnelling times for quantum electron transport

    International Nuclear Information System (INIS)

    Rudge, Samuel L.; Kosov, Daniel S.

    2016-01-01

    In electron transport, the tunnelling time is the time taken for an electron to tunnel out of a system after it has tunnelled in. We define the tunnelling time distribution for quantum processes in a dissipative environment and develop a practical approach for calculating it, where the environment is described by the general Markovian master equation. We illustrate the theory by using the rate equation to compute the tunnelling time distribution for electron transport through a molecular junction. The tunnelling time distribution is exponential, which indicates that Markovian quantum tunnelling is a Poissonian statistical process. The tunnelling time distribution is used not only to study the quantum statistics of tunnelling along the average electric current but also to analyse extreme quantum events where an electron jumps against the applied voltage bias. The average tunnelling time shows distinctly different temperature dependence for p- and n-type molecular junctions and therefore provides a sensitive tool to probe the alignment of molecular orbitals relative to the electrode Fermi energy.

  1. Tube-dwelling invertebrates

    NARCIS (Netherlands)

    Hölker, Franz; Vanni, Michael J.; Kuiper, Jan J.; Meile, Christof; Grossart, Hans Peter; Stief, Peter; Adrian, Rita; Lorke, Andreas; Dellwig, Olaf; Brand, Andreas; Hupfer, Michael; Mooij, Wolf M.; Nützmann, Gunnar; Lewandowski, Jörg

    2015-01-01

    There is ample evidence that tube-dwelling invertebrates such as chironomids significantly alter multiple important ecosystem functions, particularly in shallow lakes. Chironomids pump large water volumes, and associated suspended and dissolved substances, through the sediment and thereby compete

  2. Radon in dwellings

    International Nuclear Information System (INIS)

    1987-01-01

    This report gives a review of the present situation in Sweden concerning the knowledge and research on radon in dwellings.The responsibilities and need for actions in this field are examined. Costs and possibilities for financial help to install radonreducing equipment are also treated. (L.E.)

  3. ISSUES IN MOBILE DISTRIBUTED REAL TIME DATABASES: PERFORMANCE AND REVIEW

    OpenAIRE

    VISHNU SWAROOP,; Gyanendra Kumar Gupta,; UDAI SHANKER

    2011-01-01

    Increase in handy and small electronic devices in computing fields; it makes the computing more popularand useful in business. Tremendous advances in wireless networks and portable computing devices have led to development of mobile computing. Support of real time database system depending upon thetiming constraints, due to availability of data distributed database, and ubiquitous computing pull the mobile database concept, which emerges them in a new form of technology as mobile distributed ...

  4. Time dependent temperature distribution in pulsed Ti:sapphire lasers

    Science.gov (United States)

    Buoncristiani, A. Martin; Byvik, Charles E.; Farrukh, Usamah O.

    1988-01-01

    An expression is derived for the time dependent temperature distribution in a finite solid state laser rod for an end-pumped beam of arbitrary shape. The specific case of end pumping by circular (constant) or Gaussian beam is described. The temperature profile for a single pump pulse and for repetitive pulse operation is discussed. The particular case of the temperature distribution in a pulsed titanium:sapphire rod is considered.

  5. Reservoir theory, groundwater transit time distributions, and lumped parameter models

    International Nuclear Information System (INIS)

    Etcheverry, D.; Perrochet, P.

    1999-01-01

    The relation between groundwater residence times and transit times is given by the reservoir theory. It allows to calculate theoretical transit time distributions in a deterministic way, analytically, or on numerical models. Two analytical solutions validates the piston flow and the exponential model for simple conceptual flow systems. A numerical solution of a hypothetical regional groundwater flow shows that lumped parameter models could be applied in some cases to large-scale, heterogeneous aquifers. (author)

  6. Processor tradeoffs in distributed real-time systems

    Science.gov (United States)

    Krishna, C. M.; Shin, Kang G.; Bhandari, Inderpal S.

    1987-01-01

    The problem of the optimization of the design of real-time distributed systems is examined with reference to a class of computer architectures similar to the continuously reconfigurable multiprocessor flight control system structure, CM2FCS. Particular attention is given to the impact of processor replacement and the burn-in time on the probability of dynamic failure and mean cost. The solution is obtained numerically and interpreted in the context of real-time applications.

  7. Properties of Distributed Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    Nielsen, M.; Sassone, V.; Srba, J.

    2001-01-01

    In [12] we started a research on a distributed-timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. This formalism enables to model e.g. hardware architectures like GALS. We give a formal...... definition of process semantics for our model and investigate several properties of local versus global timing: expressiveness, reachability and coverability....

  8. Modeling highway travel time distribution with conditional probability models

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Neto, Francisco Moraes [ORNL; Chin, Shih-Miao [ORNL; Hwang, Ho-Ling [ORNL; Han, Lee [University of Tennessee, Knoxville (UTK)

    2014-01-01

    ABSTRACT Under the sponsorship of the Federal Highway Administration's Office of Freight Management and Operations, the American Transportation Research Institute (ATRI) has developed performance measures through the Freight Performance Measures (FPM) initiative. Under this program, travel speed information is derived from data collected using wireless based global positioning systems. These telemetric data systems are subscribed and used by trucking industry as an operations management tool. More than one telemetric operator submits their data dumps to ATRI on a regular basis. Each data transmission contains truck location, its travel time, and a clock time/date stamp. Data from the FPM program provides a unique opportunity for studying the upstream-downstream speed distributions at different locations, as well as different time of the day and day of the week. This research is focused on the stochastic nature of successive link travel speed data on the continental United States Interstates network. Specifically, a method to estimate route probability distributions of travel time is proposed. This method uses the concepts of convolution of probability distributions and bivariate, link-to-link, conditional probability to estimate the expected distributions for the route travel time. Major contribution of this study is the consideration of speed correlation between upstream and downstream contiguous Interstate segments through conditional probability. The established conditional probability distributions, between successive segments, can be used to provide travel time reliability measures. This study also suggests an adaptive method for calculating and updating route travel time distribution as new data or information is added. This methodology can be useful to estimate performance measures as required by the recent Moving Ahead for Progress in the 21st Century Act (MAP 21).

  9. Sample path analysis and distributions of boundary crossing times

    CERN Document Server

    Zacks, Shelemyahu

    2017-01-01

    This monograph is focused on the derivations of exact distributions of first boundary crossing times of Poisson processes, compound Poisson processes, and more general renewal processes.  The content is limited to the distributions of first boundary crossing times and their applications to various stochastic models. This book provides the theory and techniques for exact computations of distributions and moments of level crossing times. In addition, these techniques could replace simulations in many cases, thus providing more insight about the phenomenona studied. This book takes a general approach for studying telegraph processes and is based on nearly thirty published papers by the author and collaborators over the past twenty five years.  No prior knowledge of advanced probability is required, making the book widely available to students and researchers in applied probability, operations research, applied physics, and applied mathematics. .

  10. Time Stamp Synchronization of PEFP Distributed Control Systems

    International Nuclear Information System (INIS)

    Song, Young Gi; An, Eun Mi; Kwon, Hyeok Jung; Cho, Yong Sub

    2010-01-01

    Proton Engineering Frontier Project (PEFP) proton linac consists of several types of control systems, such as soft Input Output Controllers (IOC) and embedded IOC based on Experimental Physics Industrial Control System (EPICS) for each subsection of PEFP facility. One of the important factors is that IOC's time clock is synchronized. The synchronized time and time stamp can be achieved with Network Time Protocol (NTP) and EPICS time stamp record without timing hardware. The requirement of the time accuracy of IOCs is less than 1 second. The main objective of this study is to configure a master clock and produce Process Variable (PV) time stamps using local CPU time synchronized from the master clock. The distributed control systems are attached on PEFP control network

  11. Real-time communication for distributed plasma control systems

    Energy Technology Data Exchange (ETDEWEB)

    Luchetta, A. [Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Corso Stati Uniti 4, Padova 35127 (Italy)], E-mail: adriano.luchetta@igi.cnr.it; Barbalace, A.; Manduchi, G.; Soppelsa, A.; Taliercio, C. [Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Corso Stati Uniti 4, Padova 35127 (Italy)

    2008-04-15

    Real-time control applications will benefit in the near future from the enhanced performance provided by multi-core processor architectures. Nevertheless real-time communication will continue to be critical in distributed plasma control systems where the plant under control typically is distributed over a wide area. At RFX-mod real-time communication is crucial for hard real-time plasma control, due to the distributed architecture of the system, which consists of several VMEbus stations. The system runs under VxWorks and uses Gigabit Ethernet for sub-millisecond real-time communication. To optimize communication in the system, a set of detailed measurements has been carried out on the target platforms (Motorola MVME5100 and MVME5500) using either the VxWorks User Datagram Protocol (UDP) stack or raw communication based on the data link layer. Measurements have been carried out also under Linux, using its UDP stack or, in alternative, RTnet, an open source hard real-time network protocol stack. RTnet runs under Xenomai or RTAI, two popular real-time extensions based on the Linux kernel. The paper reports on the measurements carried out and compares the results, showing that the performance obtained by using open source code is suitable for sub-millisecond real-time communication in plasma control.

  12. Time Synchronization and Distribution Mechanisms for Space Networks

    Science.gov (United States)

    Woo, Simon S.; Gao, Jay L.; Clare, Loren P.; Mills, David L.

    2011-01-01

    This work discusses research on the problems of synchronizing and distributing time information between spacecraft based on the Network Time Protocol (NTP), where NTP is a standard time synchronization protocol widely used in the terrestrial network. The Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol was designed and developed for synchronizing spacecraft that are in proximity where proximity is less than 100,000 km distant. A particular application is synchronization between a Mars orbiter and rover. Lunar scenarios as well as outer-planet deep space mother-ship-probe missions may also apply. Spacecraft with more accurate time information functions as a time-server, and the other spacecraft functions as a time-client. PITS can be easily integrated and adaptable to the CCSDS Proximity-1 Space Link Protocol with minor modifications. In particular, PITS can take advantage of the timestamping strategy that underlying link layer functionality provides for accurate time offset calculation. The PITS algorithm achieves time synchronization with eight consecutive space network time packet exchanges between two spacecraft. PITS can detect and avoid possible errors from receiving duplicate and out-of-order packets by comparing with the current state variables and timestamps. Further, PITS is able to detect error events and autonomously recover from unexpected events that can possibly occur during the time synchronization and distribution process. This capability achieves an additional level of protocol protection on top of CRC or Error Correction Codes. PITS is a lightweight and efficient protocol, eliminating the needs for explicit frame sequence number and long buffer storage. The PITS protocol is capable of providing time synchronization and distribution services for a more general domain where multiple entities need to achieve time synchronization using a single point-to-point link.

  13. First-Passage-Time Distribution for Variable-Diffusion Processes

    Science.gov (United States)

    Barney, Liberty; Gunaratne, Gemunu H.

    2017-05-01

    First-passage-time distribution, which presents the likelihood of a stock reaching a pre-specified price at a given time, is useful in establishing the value of financial instruments and in designing trading strategies. First-passage-time distribution for Wiener processes has a single peak, while that for stocks exhibits a notable second peak within a trading day. This feature has only been discussed sporadically—often dismissed as due to insufficient/incorrect data or circumvented by conversion to tick time—and to the best of our knowledge has not been explained in terms of the underlying stochastic process. It was shown previously that intra-day variations in the market can be modeled by a stochastic process containing two variable-diffusion processes (Hua et al. in, Physica A 419:221-233, 2015). We show here that the first-passage-time distribution of this two-stage variable-diffusion model does exhibit a behavior similar to the empirical observation. In addition, we find that an extended model incorporating overnight price fluctuations exhibits intra- and inter-day behavior similar to those of empirical first-passage-time distributions.

  14. MicROS-drt: supporting real-time and scalable data distribution in distributed robotic systems.

    Science.gov (United States)

    Ding, Bo; Wang, Huaimin; Fan, Zedong; Zhang, Pengfei; Liu, Hui

    A primary requirement in distributed robotic software systems is the dissemination of data to all interested collaborative entities in a timely and scalable manner. However, providing such a service in a highly dynamic and resource-limited robotic environment is a challenging task, and existing robot software infrastructure has limitations in this aspect. This paper presents a novel robot software infrastructure, micROS-drt, which supports real-time and scalable data distribution. The solution is based on a loosely coupled data publish-subscribe model with the ability to support various time-related constraints. And to realize this model, a mature data distribution standard, the data distribution service for real-time systems (DDS), is adopted as the foundation of the transport layer of this software infrastructure. By elaborately adapting and encapsulating the capability of the underlying DDS middleware, micROS-drt can meet the requirement of real-time and scalable data distribution in distributed robotic systems. Evaluation results in terms of scalability, latency jitter and transport priority as well as the experiment on real robots validate the effectiveness of this work.

  15. Traversal-time distribution for a classical time-modulated barrier

    International Nuclear Information System (INIS)

    Mateos, J.L.

    1999-01-01

    The classical problem of a time-modulated barrier, inspired by the Buettiker and Landauer model to study the tunneling times, is analyzed. We show that the traversal-time distribution of an ensemble of non-interacting particles that arrives at the oscillating barrier, obeys a distribution with a power-law tail. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Global time-size distribution of volcanic eruptions on Earth.

    Science.gov (United States)

    Papale, Paolo

    2018-05-01

    Volcanic eruptions differ enormously in their size and impacts, ranging from quiet lava flow effusions along the volcano flanks to colossal events with the potential to affect our entire civilization. Knowledge of the time and size distribution of volcanic eruptions is of obvious relevance for understanding the dynamics and behavior of the Earth system, as well as for defining global volcanic risk. From the analysis of recent global databases of volcanic eruptions extending back to more than 2 million years, I show here that the return times of eruptions with similar magnitude follow an exponential distribution. The associated relative frequency of eruptions with different magnitude displays a power law, scale-invariant distribution over at least six orders of magnitude. These results suggest that similar mechanisms subtend to explosive eruptions from small to colossal, raising concerns on the theoretical possibility to predict the magnitude and impact of impending volcanic eruptions.

  17. Distributed Scheduling in Time Dependent Environments: Algorithms and Analysis

    OpenAIRE

    Shmuel, Ori; Cohen, Asaf; Gurewitz, Omer

    2017-01-01

    Consider the problem of a multiple access channel in a time dependent environment with a large number of users. In such a system, mostly due to practical constraints (e.g., decoding complexity), not all users can be scheduled together, and usually only one user may transmit at any given time. Assuming a distributed, opportunistic scheduling algorithm, we analyse the system's properties, such as delay, QoS and capacity scaling laws. Specifically, we start with analyzing the performance while \\...

  18. Development of optical fiber frequency and time distribution systems

    Science.gov (United States)

    Lutes, G.

    1982-01-01

    The development of ultra stable optical fiber distribution systems for the dissemination of frequency and timing references is reported. The ultimate design goals for these systems are a frequency stability of 10 to the -17 power for tau or = 100 sec and time stability of + or - 0.1 ns for 1 year and operation over distances or = 30 km. A prototype system is reviewed and progress is discussed.

  19. The Design of a Real-Time Distributed System

    NARCIS (Netherlands)

    Hertzberger, L.O.; Mullender, S.J.; Poletiek, G.; van Renesse, R.; Tanenbaum, A.S.; Tuynman, F.; Vermeulen, J.C.

    1986-01-01

    In modern physics experiments an increasing number and variety of programmable processors is used. As a consequence, a software environment is needed that provides an integrated approach to development, testing and use of real-time distributed software. This contribution is based on work being done

  20. Resource Optimization in Distributed Real-Time Multimedia Applications

    NARCIS (Netherlands)

    Yang, R.; van der Mei, R.D.; Roubos, D.; Seinstra, F.J.; Bal, H.E.

    2012-01-01

    The research area of multimedia content analysis (MMCA) considers all aspects of the automated extraction of knowledge from multimedia archives and data streams. To adhere to strict time constraints, large-scalemultimedia applications typically are being executed on distributed systems consisting of

  1. Fourier transform distribution function of relaxation times; application and limitations

    NARCIS (Netherlands)

    Boukamp, Bernard A.

    2015-01-01

    A simple Fourier transform (FT) method is presented for obtaining a Distribution Function of Relaxation Times (DFRT) for electrochemical impedance spectroscopy (EIS) data. By using a special data extension procedure the FT is performed over the range from -∞ ≤ lnω ≤ + ∞. The integration procedure is

  2. Occupation times distribution for Brownian motion on graphs

    CERN Document Server

    Desbois, J

    2002-01-01

    Considering a Brownian motion on a general graph, we study the joint law for the occupation times on all the bonds. In particular, we show that the Laplace transform of this distribution can be expressed as the ratio of two determinants. We give two formulations, with arc or vertex matrices, for this result and discuss a simple example. (letter to the editor)

  3. Distribution of diffusion times determined by fluorescence (lifetime) correlation spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Pánek, Jiří; Loukotová, Lenka; Hrubý, Martin; Štěpánek, Petr

    2018-01-01

    Roč. 51, č. 8 (2018), s. 2796-2804 ISSN 0024-9297 R&D Projects: GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : polymer solution * fluorescence correlation spectroscopy * diffusion time distribution Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 5.835, year: 2016

  4. Distributional curvature of time-dependent cosmic strings

    OpenAIRE

    Wilson, J P

    1997-01-01

    Colombeau's theory of generalised functions is used to calculate the contributions, at the rotation axis, to the distributional curvature for a time-dependent radiating cosmic string, and hence the mass per unit length of the string source. This mass per unit length is compared with the mass at null infinity, giving evidence for a global energy conservation law.

  5. Residence Time Distributions in a Cold, Confined Swirl Flow

    DEFF Research Database (Denmark)

    Lans, Robert Pieter Van Der; Glarborg, Peter; Dam-Johansen, Kim

    1997-01-01

    Residence time distributions (RTD) in a confined, cold swirling flow have been measured with a fast-response probe and helium as a tracer. The test-rig represented a scaled down version of a burner. The effect of variation of flow velocities and swirl angle on the flow pattern in the near...

  6. Towards a Notion of Distributed Time for Petri Nets

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Sassone, Vladimiro; Srba, Jiří

    2001-01-01

    We set the ground for research on a timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. The novelty is that, rather than a single global clock, we use a set of unrelated clocks — possibly o...... per place — allowing a local timing as well as distributed time synchronisation. We give a formal definition of the model and investigate properties of local versus global timing, including decidability issues and notions of processes of the respective models.......We set the ground for research on a timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. The novelty is that, rather than a single global clock, we use a set of unrelated clocks — possibly one...

  7. Sound classification of dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2012-01-01

    National schemes for sound classification of dwellings exist in more than ten countries in Europe, typically published as national standards. The schemes define quality classes reflecting different levels of acoustical comfort. Main criteria concern airborne and impact sound insulation between...... dwellings, facade sound insulation and installation noise. The schemes have been developed, implemented and revised gradually since the early 1990s. However, due to lack of coordination between countries, there are significant discrepancies, and new standards and revisions continue to increase the diversity...... is needed, and a European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs 2009-2013, one of the main objectives being to prepare a proposal for a European sound classification scheme with a number of quality...

  8. Real-time modeling and simulation of distribution feeder and distributed resources

    Science.gov (United States)

    Singh, Pawan

    The analysis of the electrical system dates back to the days when analog network analyzers were used. With the advent of digital computers, many programs were written for power-flow and short circuit analysis for the improvement of the electrical system. Real-time computer simulations can answer many what-if scenarios in the existing or the proposed power system. In this thesis, the standard IEEE 13-Node distribution feeder is developed and validated on a real-time platform OPAL-RT. The concept and the challenges of the real-time simulation are studied and addressed. Distributed energy resources include some of the commonly used distributed generation and storage devices like diesel engine, solar photovoltaic array, and battery storage system are modeled and simulated on a real-time platform. A microgrid encompasses a portion of an electric power distribution which is located downstream of the distribution substation. Normally, the microgrid operates in paralleled mode with the grid; however, scheduled or forced isolation can take place. In such conditions, the microgrid must have the ability to operate stably and autonomously. The microgrid can operate in grid connected and islanded mode, both the operating modes are studied in the last chapter. Towards the end, a simple microgrid controller modeled and simulated on the real-time platform is developed for energy management and protection for the microgrid.

  9. Dwelling with design

    OpenAIRE

    Paavilainen, Heidi

    2013-01-01

    Dwelling with Design offers a throughout look at the domestic meanings of design. The research is based on studying households in and around Helsinki, in order to find out what role, if any, design plays in the domestication of a product. The picture emerging from the research is quite different from design’s public and professional image represented for example in the interior decoration magazines, where designed qualities such as usability, reliability, interesting branding and aesthetic co...

  10. Distributed, Embedded and Real-time Java Systems

    CERN Document Server

    Wellings, Andy

    2012-01-01

    Research on real-time Java technology has been prolific over the past decade, leading to a large number of corresponding hardware and software solutions, and frameworks for distributed and embedded real-time Java systems.  This book is aimed primarily at researchers in real-time embedded systems, particularly those who wish to understand the current state of the art in using Java in this domain.  Much of the work in real-time distributed, embedded and real-time Java has focused on the Real-time Specification for Java (RTSJ) as the underlying base technology, and consequently many of the Chapters in this book address issues with, or solve problems using, this framework. Describes innovative techniques in: scheduling, memory management, quality of service and communication systems supporting real-time Java applications; Includes coverage of multiprocessor embedded systems and parallel programming; Discusses state-of-the-art resource management for embedded systems, including Java’s real-time garbage collect...

  11. Real-time Control Mediation in Agile Distributed Software Development

    DEFF Research Database (Denmark)

    Persson, John Stouby; Aaen, Ivan; Mathiassen, Lars

    2008-01-01

    Agile distributed environments pose particular challenges related to control of quality and collaboration in software development. Moreover, while face-to-face interaction is fundamental in agile development, distributed environments must rely extensively on mediated interactions. On this backdrop...... control was mediated over distance by technology through real-time exchanges. Contrary to previous research, the analysis suggests that both formal and informal elements of real-time mediated control were used; that evolving goals and adjustment of expectations were two of the main issues in real......-time mediated control exchanges; and, that the actors, despite distances in space and culture, developed a clan-like pattern mediated by technology to help control quality and collaboration in software development....

  12. Interevent time distribution in seismicity: A theoretical approach

    International Nuclear Information System (INIS)

    Molchan, G.

    2004-09-01

    This paper presents an analysis of the distribution of the time τ between two consecutive events in a stationary point process. The study is motivated by the discovery of unified scaling laws for τ for the case of seismic events. We demonstrate that these laws cannot exist simultaneously in a seismogenic area. Under very natural assumptions we show that if, after resealing to ensure Eτ = 1, the interevent time has a universal distribution F, then F must be exponential. In other words, Corral's unified scaling law cannot exist in the whole range of time. In the framework of a general cluster model we discuss the parameterization of an empirical unified law and the physical meaning of the parameters involved

  13. Precision time distribution within a deep space communications complex

    Science.gov (United States)

    Curtright, J. B.

    1972-01-01

    The Precision Time Distribution System (PTDS) at the Golstone Deep Space Communications Complex is a practical application of existing technology to the solution of a local problem. The problem was to synchronize four station timing systems to a master source with a relative accuracy consistently and significantly better than 10 microseconds. The solution involved combining a precision timing source, an automatic error detection assembly and a microwave distribution network into an operational system. Upon activation of the completed PTDS two years ago, synchronization accuracy at Goldstone (two station relative) was improved by an order of magnitude. It is felt that the validation of the PTDS mechanization is now completed. Other facilities which have site dispersion and synchronization accuracy requirements similar to Goldstone may find the PTDS mechanization useful in solving their problem. At present, the two station relative synchronization accuracy at Goldstone is better than one microsecond.

  14. Reflexive reasoning for distributed real-time systems

    Science.gov (United States)

    Goldstein, David

    1994-01-01

    This paper discusses the implementation and use of reflexive reasoning in real-time, distributed knowledge-based applications. Recently there has been a great deal of interest in agent-oriented systems. Implementing such systems implies a mechanism for sharing knowledge, goals and other state information among the agents. Our techniques facilitate an agent examining both state information about other agents and the parameters of the knowledge-based system shell implementing its reasoning algorithms. The shell implementing the reasoning is the Distributed Artificial Intelligence Toolkit, which is a derivative of CLIPS.

  15. A distributed scheduling algorithm for heterogeneous real-time systems

    Science.gov (United States)

    Zeineldine, Osman; El-Toweissy, Mohamed; Mukkamala, Ravi

    1991-01-01

    Much of the previous work on load balancing and scheduling in distributed environments was concerned with homogeneous systems and homogeneous loads. Several of the results indicated that random policies are as effective as other more complex load allocation policies. The effects of heterogeneity on scheduling algorithms for hard real time systems is examined. A distributed scheduler specifically to handle heterogeneities in both nodes and node traffic is proposed. The performance of the algorithm is measured in terms of the percentage of jobs discarded. While a random task allocation is very sensitive to heterogeneities, the algorithm is shown to be robust to such non-uniformities in system components and load.

  16. Radon measurements in mines and dwellings

    International Nuclear Information System (INIS)

    Urban, M.

    1985-01-01

    Radon measurements using a time integrating passive radon dosemeter (MAKROFOL track etch detector) have been performed in Brazilian and German mines and dwellings. The present state of the measurement technique is summarized. The results are presented together with exposure calculations and dose estimations for occupational exposure in open pit and underground mines and for the general public in houses. (orig./HP) [de

  17. An approach to a real-time distribution system

    Science.gov (United States)

    Kittle, Frank P., Jr.; Paddock, Eddie J.; Pocklington, Tony; Wang, Lui

    1990-01-01

    The requirements of a real-time data distribution system are to provide fast, reliable delivery of data from source to destination with little or no impact to the data source. In this particular case, the data sources are inside an operational environment, the Mission Control Center (MCC), and any workstation receiving data directly from the operational computer must conform to the software standards of the MCC. In order to supply data to development workstations outside of the MCC, it is necessary to use gateway computers that prevent unauthorized data transfer back to the operational computers. Many software programs produced on the development workstations are targeted for real-time operation. Therefore, these programs must migrate from the development workstation to the operational workstation. It is yet another requirement for the Data Distribution System to ensure smooth transition of the data interfaces for the application developers. A standard data interface model has already been set up for the operational environment, so the interface between the distribution system and the application software was developed to match that model as closely as possible. The system as a whole therefore allows the rapid development of real-time applications without impacting the data sources. In summary, this approach to a real-time data distribution system provides development users outside of the MCC with an interface to MCC real-time data sources. In addition, the data interface was developed with a flexible and portable software design. This design allows for the smooth transition of new real-time applications to the MCC operational environment.

  18. Failure modes and natural control time for distributed vibrating systems

    International Nuclear Information System (INIS)

    Reid, R.M.

    1994-01-01

    The eigenstructure of the Gram matrix of frequency exponentials is used to study linear vibrating systems of hyperbolic type with distributed control. Using control norm as a practical measure of controllability and the vibrating string as a prototype, it is demonstrated that hyperbolic systems have a natural control time, even when only finitely many modes are excited. For shorter control times there are identifiable control failure modes which can be steered to zero only with very high cost in control norm. Both natural control time and the associated failure modes are constructed for linear fluids, strings, and beams, making note of the essential algorithms and Mathematica code, and displaying results graphically

  19. On response time and cycle time distributions in a two-stage cyclic queue

    NARCIS (Netherlands)

    Boxma, O.J.; Donk, P.

    1982-01-01

    We consider a two-stage closed cyclic queueing model. For the case of an exponential server at each queue we derive the joint distribution of the successive response times of a custumer at both queues, using a reversibility argument. This joint distribution turns out to have a product form. The

  20. Optimization of Time-Partitions for Mixed-Criticality Real-Time Distributed Embedded Systems

    DEFF Research Database (Denmark)

    Tamas-Selicean, Domitian; Pop, Paul

    2011-01-01

    In this paper we are interested in mixed-criticality embedded real-time applications mapped on distributed heterogeneous architectures. The architecture provides both spatial and temporal partitioning, thus enforcing enough separation for the critical applications. With temporal partitioning, each...

  1. Real-time dynamic imaging of virus distribution in vivo.

    Directory of Open Access Journals (Sweden)

    Sean E Hofherr

    2011-02-01

    Full Text Available The distribution of viruses and gene therapy vectors is difficult to assess in a living organism. For instance, trafficking in murine models can usually only be assessed after sacrificing the animal for tissue sectioning or extraction. These assays are laborious requiring whole animal sectioning to ascertain tissue localization. They also obviate the ability to perform longitudinal or kinetic studies in one animal. To track viruses after systemic infection, we have labeled adenoviruses with a near-infrared (NIR fluorophore and imaged these after intravenous injection in mice. Imaging was able to track and quantitate virus particles entering the jugular vein simultaneous with injection, appearing in the heart within 500 milliseconds, distributing in the bloodstream and throughout the animal within 7 seconds, and that the bulk of virus distribution was essentially complete within 3 minutes. These data provide the first in vivo real-time tracking of the rapid initial events of systemic virus infection.

  2. Implementation of a Wireless Time Distribution Testbed Protected with Quantum Key Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Bonior, Jason D [ORNL; Evans, Philip G [ORNL; Sheets, Gregory S [ORNL; Jones, John P [ORNL; Flynn, Toby H [ORNL; O' Neil, Lori Ross [Pacific Northwest National Laboratory (PNNL); Hutton, William [Pacific Northwest National Laboratory (PNNL); Pratt, Richard [Pacific Northwest National Laboratory (PNNL); Carroll, Thomas E. [Pacific Northwest National Laboratory (PNNL)

    2017-01-01

    Secure time transfer is critical for many timesensitive applications. the Global Positioning System (GPS) which is often used for this purpose has been shown to be susceptible to spoofing attacks. Quantum Key Distribution offers a way to securely generate encryption keys at two locations. Through careful use of this information it is possible to create a system that is more resistant to spoofing attacks. In this paper we describe our work to create a testbed which utilizes QKD and traditional RF links. This testbed will be used for the development of more secure and spoofing resistant time distribution protocols.

  3. Protein Intake and Distribution in Relation to Physical Functioning and Quality of Life in Community-Dwelling Elderly People: Acknowledging the Role of Physical Activity

    NARCIS (Netherlands)

    Haaf, ten Dominique; Dongen, van E.J.I.; Nuijten, M.; Eijsvogels, Thijs; Groot, de C.P.G.M.; Hopman, Maria

    2018-01-01

    Increasing total protein intake and a spread protein intake distribution are potential strategies to attenuate sarcopenia related loss of physical function and quality of life. The aim of this cross-sectional study was to investigate whether protein intake and protein intake distribution are

  4. Sound classification of dwellings in the Nordic countries

    DEFF Research Database (Denmark)

    Rindel, Jens Holger; Turunen-Rise, Iiris

    1997-01-01

    be met. The classification system is based on limit values for airborne sound insulation, impact sound pressure level, reverberation time and indoor and outdoor noise levels. The purpose of the standard is to offer a tool for specification of a standardised acoustic climate and to promote constructors......A draft standard INSTA 122:1997 on sound classification of dwellings is for voting as a common national standard in the Nordic countries (Denmark, Norway, Sweden, Finland, Iceland) and in Estonia. The draft standard specifies a sound classification system with four classes A, B, C and D, where...... class C is proposed as the future minimum requirements for new dwellings. The classes B and A define criteria for dwellings with improved or very good acoustic conditions, whereas class D may be used for older, renovated dwellings in which the acoustic quality level of a new dwelling cannot reasonably...

  5. Areal and time distributions of volcanic formations on Mars

    International Nuclear Information System (INIS)

    Katterfeld, G.N.; Vityaz, V.I.

    1987-01-01

    The analysis of igneous rock distribution has been fulfilled on the basis of the geomorphological map of Mars at scale 1:5,000,000, according to data obtained from interpretation of 1:2,000,000 scale pictures of Mariner 9, Mars 4, Mars 5, Viking 1 and 2. Areological areas are listed as having been distinguished as the stratigraphic basis for a martian time scale. The area of volcanic eruptions and the number of eruptive centers are calculated on 10 x 10 deg cells and for each areological eras. The largest area of eruptive happening at different times is related with Tharsis tectonic uplift. The study of distribution of igneous rock area and volcanic centers number on 10 deg sectors and zones revealed the concentration belts of volcanic formations

  6. Areal and time distributions of volcanic formations on Mars

    Science.gov (United States)

    Katterfeld, G. N.; Vityaz, V. I.

    1987-01-01

    The analysis of igneous rock distribution has been fulfilled on the basis of the geomorphological map of Mars at scale 1:5,000,000, according to data obtained from interpretation of 1:2,000,000 scale pictures of Mariner 9, Mars 4, Mars 5, Viking 1 and 2. Areological areas are listed as having been distinguished as the stratigraphic basis for a martian time scale. The area of volcanic eruptions and the number of eruptive centers are calculated on 10 x 10 deg cells and for each areological eras. The largest area of eruptive happening at different times is related with Tharsis tectonic uplift. The study of distribution of igneous rock area and volcanic centers number on 10 deg sectors and zones revealed the concentration belts of volcanic formations.

  7. An Optimization Framework for Dynamic, Distributed Real-Time Systems

    Science.gov (United States)

    Eckert, Klaus; Juedes, David; Welch, Lonnie; Chelberg, David; Bruggerman, Carl; Drews, Frank; Fleeman, David; Parrott, David; Pfarr, Barbara

    2003-01-01

    Abstract. This paper presents a model that is useful for developing resource allocation algorithms for distributed real-time systems .that operate in dynamic environments. Interesting aspects of the model include dynamic environments, utility and service levels, which provide a means for graceful degradation in resource-constrained situations and support optimization of the allocation of resources. The paper also provides an allocation algorithm that illustrates how to use the model for producing feasible, optimal resource allocations.

  8. A time reference distribution concept for a time division communication network

    Science.gov (United States)

    Stover, H. A.

    1973-01-01

    Starting with an assumed ideal network having perfect clocks at every node and known fixed transmission delays between nodes, the effects of adding tolerances to both transmission delays and nodal clocks is described. The advantages of controlling tolerances on time rather than frequency are discussed. Then a concept is presented for maintaining these tolerances on time throughout the network. This concept, called time reference distribution, is a systematic technique for distributing time reference to all nodes of the network. It is reliable, survivable and possesses many other desirable characteristics. Some of its features such as an excellent self monitoring capability will be pointed out. Some preliminary estimates of the accuracy that might be expected are developed and there is a brief discussion of the impact upon communication system costs. Time reference distribution is a concept that appears very attractive. It has not had experimental evaluation and has not yet been endorsed for use in any communication network.

  9. 25 CFR 700.53 - Dwelling, replacement.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Dwelling, replacement. 700.53 Section 700.53 Indians THE... Policies and Instructions Definitions § 700.53 Dwelling, replacement. The term replacement dwelling means a dwelling selected by the head of a household as a replacement dwelling that meets the criteria of this...

  10. A Distributed Synchronization and Timing System on the EAST Tokamak

    Science.gov (United States)

    Luo, Jiarong; Wu, Yichun; Shu, Yantai

    2008-08-01

    A key requirement for the EAST distributed control system (EASTDCS) is time synchronization to an accuracy of RTOS). The DSTS provides the control and the data acquisition systems with reference clocks (0.01 Hz 10 MHz) and delayed trigger times ( 1 mus 4294 s). These are produced by a Core Module Unit (CMU) connected by optical fibres to many Local Synchronized Node Units (LSNU). The fibres provide immunity from electrical noise and are of equal length to match clock and trigger delays between systems. This paper describes the architecture of the DSTS on the EAST tokamak and provides an overview of the characteristics of the main and local units.

  11. Time and temporality: linguistic distribution in human life-games

    DEFF Research Database (Denmark)

    Cowley, Stephen

    2014-01-01

    culture, individuals developed a knack of using linguistic distribution to link metabolism with collective ways of assessing and managing experience. Of human temporal management, the best known case is the mental time travel enabled by, among other functions, autobiographical memory. One contribution......While clock-time can be used to clarify facts, all living systems construct their own temporalities. Having illustrated the claim for foxtail grasses, it is argued that, with motility and brains, organisms came to use temporalities that build flexibility into behavior. With the rise of human...

  12. Time-optimal control of infinite order distributed parabolic systems involving time lags

    Directory of Open Access Journals (Sweden)

    G.M. Bahaa

    2014-06-01

    Full Text Available A time-optimal control problem for linear infinite order distributed parabolic systems involving constant time lags appear both in the state equation and in the boundary condition is presented. Some particular properties of the optimal control are discussed.

  13. The response time distribution in a real-time database with optimistic concurrency control

    NARCIS (Netherlands)

    Sassen, S.A.E.; Wal, van der J.

    1996-01-01

    For a real-time shared-memory database with optimistic concurrency control, an approximation for the transaction response time distribution is obtained. The model assumes that transactions arrive at the database according to a Poisson process, that every transaction uses an equal number of

  14. Accuracy of Timed Up and Go Test for screening risk of falls among community-dwelling elderly Acurácia do Timed Up and Go Test para rastrear risco de quedas em idosos da comunidade

    Directory of Open Access Journals (Sweden)

    Tiago S. Alexandre

    2012-10-01

    Full Text Available OBJECTIVE: To determine the accuracy of the Timed Up and Go Test (TUGT for screening the risk of falls among community-dwelling elderly individuals. METHOD: This is a prospective cohort study with a randomly by lots without reposition sample stratified by proportional partition in relation to gender involving 63 community-dwelling elderly individuals. Elderly individuals who reported having Parkinson's disease, a history of transitory ischemic attack, stroke and with a Mini Mental State Exam lower than the expected for the education level, were on a wheelchair and that reported a single fall in the previous six months were excluded. The TUGT, a mobility test, was the measure of interested and the occurrence of falls was the outcome. The performance of basic activities of daily living (ADL and instrumental activities of daily living (IADL was determined through the Older American Resources and Services, and the socio-demographic and clinical data were determined through the use of additional questionnaires. Receiver Operating Characteristic Curves were used to analyze the sensitivity and specificity of the TUGT. RESULTS: Elderly individuals who fell had greater difficulties in ADL and IADL (pOBJETIVO: Determinar a acurácia do Timed Up and Go Test (TUGT para rastrear risco de quedas em idosos da comunidade. MÉTODO: Trata-se de um estudo de coorte prospectivo com amostra sorteada aleatoriamente, sem reposição e estratificada por partilha proporcional em relação ao sexo de 63 idosos da comunidade. Excluíram-se idosos com doença de Parkinson, ataque isquêmico transitório, acidente vascular encefálico, Miniexame do Estado Mental inferior ao considerado normal de acordo com a escolaridade, movimentação exclusiva por cadeira de rodas e relato de uma queda nos seis meses anteriores à primeira entrevista. O TUGT, um teste de mobilidade, foi a medida testada, e o desfecho, a ocorrência de queda. Mensuraram-se atividades básicas (ABVD e

  15. Distributed computing for real-time petroleum reservoir monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Ayodele, O. R. [University of Alberta, Edmonton, AB (Canada)

    2004-05-01

    Computer software architecture is presented to illustrate how the concept of distributed computing can be applied to real-time reservoir monitoring processes, permitting the continuous monitoring of the dynamic behaviour of petroleum reservoirs at much shorter intervals. The paper describes the fundamental technologies driving distributed computing, namely Java 2 Platform Enterprise edition (J2EE) by Sun Microsystems, and the Microsoft Dot-Net (Microsoft.Net) initiative, and explains the challenges involved in distributed computing. These are: (1) availability of permanently placed downhole equipment to acquire and transmit seismic data; (2) availability of high bandwidth to transmit the data; (3) security considerations; (4) adaptation of existing legacy codes to run on networks as downloads on demand; and (5) credibility issues concerning data security over the Internet. Other applications of distributed computing in the petroleum industry are also considered, specifically MWD, LWD and SWD (measurement-while-drilling, logging-while-drilling, and simulation-while-drilling), and drill-string vibration monitoring. 23 refs., 1 fig.

  16. Data distribution architecture based on standard real time protocol

    International Nuclear Information System (INIS)

    Castro, R.; Vega, J.; Pereira, A.; Portas, A.

    2009-01-01

    Data distribution architecture (DDAR) has been designed conforming to new requirements, taking into account the type of data that is going to be generated from experiments in International Thermonuclear Experimental Reactor (ITER). The main goal of this architecture is to implement a system that is able to manage on line all data that is being generated by an experiment, supporting its distribution for: processing, storing, analysing or visualizing. The first objective is to have a distribution architecture that supports long pulse experiments (even hours). The described system is able to distribute, using real time protocol (RTP), stored data or live data generated while the experiment is running. It enables researchers to access data on line instead of waiting for the end of the experiment. Other important objective is scalability, so the presented architecture can easily grow based on actual necessities, simplifying estimation and design tasks. A third important objective is security. In this sense, the architecture is based on standards, so complete security mechanisms can be applied, from secure transmission solutions until elaborated access control policies, and it is full compatible with multi-organization federation systems as PAPI or Shibboleth.

  17. Data distribution architecture based on standard real time protocol

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R. [Asociacion EURATOM/CIEMAT para Fusion, Avda. Complutense No. 22, 28040 Madrid (Spain)], E-mail: rodrigo.castro@ciemat.es; Vega, J.; Pereira, A.; Portas, A. [Asociacion EURATOM/CIEMAT para Fusion, Avda. Complutense No. 22, 28040 Madrid (Spain)

    2009-06-15

    Data distribution architecture (DDAR) has been designed conforming to new requirements, taking into account the type of data that is going to be generated from experiments in International Thermonuclear Experimental Reactor (ITER). The main goal of this architecture is to implement a system that is able to manage on line all data that is being generated by an experiment, supporting its distribution for: processing, storing, analysing or visualizing. The first objective is to have a distribution architecture that supports long pulse experiments (even hours). The described system is able to distribute, using real time protocol (RTP), stored data or live data generated while the experiment is running. It enables researchers to access data on line instead of waiting for the end of the experiment. Other important objective is scalability, so the presented architecture can easily grow based on actual necessities, simplifying estimation and design tasks. A third important objective is security. In this sense, the architecture is based on standards, so complete security mechanisms can be applied, from secure transmission solutions until elaborated access control policies, and it is full compatible with multi-organization federation systems as PAPI or Shibboleth.

  18. Waiting Time Distributions for Pattern Occurrence in a Constrained Sequence

    Directory of Open Access Journals (Sweden)

    Valeri Stefanov

    2007-01-01

    Full Text Available A binary sequence of zeros and ones is called a (d,k-sequence if it does not contain runs of zeros of length either less than d or greater than k, where d and k are arbitrary, but fixed, non-negative integers and d < k. Such sequences find an abundance of applications in communications, in particular for magnetic and optical recording. Occasionally, one requires that (d,k-sequences do not contain a specific pattern w. Therefore, distribution results concerning pattern occurrence in (d,k-sequences are of interest. In this paper we study the distribution of the waiting time until the r th occurrence of a pattern w in a random (d,k-sequence generated by a Markov source. Numerical examples are also provided.

  19. Residual distribution for general time-dependent conservation laws

    International Nuclear Information System (INIS)

    Ricchiuto, Mario; Csik, Arpad; Deconinck, Herman

    2005-01-01

    We consider the second-order accurate numerical solution of general time-dependent hyperbolic conservation laws over unstructured grids in the framework of the Residual Distribution method. In order to achieve full conservation of the linear, monotone and first-order space-time schemes of (Csik et al., 2003) and (Abgrall et al., 2000), we extend the conservative residual distribution (CRD) formulation of (Csik et al., 2002) to prismatic space-time elements. We then study the design of second-order accurate and monotone schemes via the nonlinear mapping of the local residuals of linear monotone schemes. We derive sufficient and necessary conditions for the well-posedness of the mapping. We prove that the schemes obtained with the CRD formulation satisfy these conditions by construction. Thus the nonlinear schemes proposed in this paper are always well defined. The performance of the linear and nonlinear schemes are evaluated on a series of test problems involving the solution of the Euler equations and of a two-phase flow model. We consider the resolution of strong shocks and complex interacting flow structures. The results demonstrate the robustness, accuracy and non-oscillatory character of the proposed schemes. d schemes

  20. Blocking Optimality in Distributed Real-Time Locking Protocols

    Directory of Open Access Journals (Sweden)

    Björn Bernhard Brandenburg

    2014-09-01

    Full Text Available Lower and upper bounds on the maximum priority inversion blocking (pi-blocking that is generally unavoidable in distributed multiprocessor real-time locking protocols (where resources may be accessed only from specific synchronization processors are established. Prior work on suspension-based shared-memory multiprocessor locking protocols (which require resources to be accessible from all processors has established asymptotically tight bounds of Ω(m and Ω(n maximum pi-blocking under suspension-oblivious and suspension-aware analysis, respectively, where m denotes the total number of processors and n denotes the number of tasks. In this paper, it is shown that, in the case of distributed semaphore protocols, there exist two different task allocation scenarios that give rise to distinct lower bounds. In the case of co-hosted task allocation, where application tasks may also be assigned to synchronization processors (i.e., processors hosting critical sections, Ω(Φ · n maximum pi-blocking is unavoidable for some tasks under any locking protocol under both suspension-aware and suspension-oblivious schedulability analysis, where Φ denotes the ratio of the maximum response time to the shortest period. In contrast, in the case of disjoint task allocation (i.e., if application tasks may not be assigned to synchronization processors, only Ω(m and Ω(n maximum pi-blocking is fundamentally unavoidable under suspension-oblivious and suspension-aware analysis, respectively, as in the shared-memory case. These bounds are shown to be asymptotically tight with the construction of two new distributed real-time locking protocols that ensure O(m and O(n maximum pi-blocking under suspension-oblivious and suspension-aware analysis, respectively.

  1. Topology Identification of General Dynamical Network with Distributed Time Delays

    International Nuclear Information System (INIS)

    Zhao-Yan, Wu; Xin-Chu, Fu

    2009-01-01

    General dynamical networks with distributed time delays are studied. The topology of the networks are viewed as unknown parameters, which need to be identified. Some auxiliary systems (also called the network estimators) are designed to achieve this goal. Both linear feedback control and adaptive strategy are applied in designing these network estimators. Based on linear matrix inequalities and the Lyapunov function method, the sufficient condition for the achievement of topology identification is obtained. This method can also better monitor the switching topology of dynamical networks. Illustrative examples are provided to show the effectiveness of this method. (general)

  2. Electrochemical Impedance Imaging via the Distribution of Diffusion Times

    Science.gov (United States)

    Song, Juhyun; Bazant, Martin Z.

    2018-03-01

    We develop a mathematical framework to analyze electrochemical impedance spectra in terms of a distribution of diffusion times (DDT) for a parallel array of random finite-length Warburg (diffusion) or Gerischer (reaction-diffusion) circuit elements. A robust DDT inversion method is presented based on complex nonlinear least squares regression with Tikhonov regularization and illustrated for three cases of nanostructured electrodes for energy conversion: (i) a carbon nanotube supercapacitor, (ii) a silicon nanowire Li-ion battery, and (iii) a porous-carbon vanadium flow battery. The results demonstrate the feasibility of nondestructive "impedance imaging" to infer microstructural statistics of random, heterogeneous materials.

  3. SCI-Clone/32 - a distributed real time simulation system

    International Nuclear Information System (INIS)

    Wilks, C.F.

    1986-01-01

    Advances in engineering and in particular digital computers has enabled the simulation manufacturers to deliver a realism of a kind undreamt of a decade ago. 32-bit computers ranging in processor power from several hundred thousand instructions per second to many millions are at the heart of each simulator. Gould has pioneered digital computers in simulation with real time systems using shared memory, parallel processors, 64KByte cache, and shadow memory. The market is planning for higher iteration rates, lower life cycle costs, and the development of part task products. These can be met by distributing the tasks amongst nodal computers having a unique architecture for sharing data variables with minimal contention. (Auth.)

  4. Directional short-time Fourier transform of distributions

    Directory of Open Access Journals (Sweden)

    Katerina Hadzi-Velkova Saneva

    2016-04-01

    Full Text Available Abstract In this paper we consider the directional short-time Fourier transform (DSTFT that was introduced and investigated in (Giv in J. Math. Anal. Appl. 399:100-107, 2013. We analyze the DSTFT and its transpose on test function spaces S ( R n $\\mathcal {S}(\\mathbb {R}^{n}$ and S ( Y 2 n $\\mathcal {S}(\\mathbb {Y}^{2n}$ , respectively, and prove the continuity theorems on these spaces. Then the obtained results are used to extend the DSTFT to spaces of distributions.

  5. Time gated phase-correlation distributed Brillouin fibre sensor

    Science.gov (United States)

    Denisov, Andrey; Soto, Marcelo A.; Thévenaz, Luc

    2013-05-01

    A random access distributed Brillouin fibre sensor is presented, based on phase modulation using a pseudo-random bit sequence (PRBS) together with time gating. The standard phase-correlation technique is known to show a noise level increasing linearly with the number of measured points due to weak gratings generated randomly along the whole sensing fibre. Here we show how intensity modulated pump and time gated detection significantly improve the signal-tonoise ratio (SNR) of the system with no impact on the spatial resolution. A measurement with 1.1 cm spatial resolution over 3.3 km is demonstrated, representing 300'000 equivalent points. The limitations of the proposed technique are discussed through the paper.

  6. The response-time distribution in a real-time database with optimistic concurrency control and constant execution times

    NARCIS (Netherlands)

    Sassen, S.A.E.; Wal, van der J.

    1997-01-01

    For a real-time shared-memory database with optimistic concurrency control, an approximation for the transaction response-time distribution is obtained. The model assumes that transactions arrive at the database according to a Poisson process, that every transaction uses an equal number of

  7. The response-time distribution in a real-time database with optimistic concurrency control and exponential execution times

    NARCIS (Netherlands)

    Sassen, S.A.E.; Wal, van der J.

    1997-01-01

    For a real-time shared-memory database with optimistic concurrency control, an approximation for the transaction response-time distribution is obtained. The model assumes that transactions arrive at the database according to a Poisson process, that every transaction takes an exponential execution

  8. Continuous time modelling of dynamical spatial lattice data observed at sparsely distributed times

    DEFF Research Database (Denmark)

    Rasmussen, Jakob Gulddahl; Møller, Jesper

    2007-01-01

    Summary. We consider statistical and computational aspects of simulation-based Bayesian inference for a spatial-temporal model based on a multivariate point process which is only observed at sparsely distributed times. The point processes are indexed by the sites of a spatial lattice......, and they exhibit spatial interaction. For specificity we consider a particular dynamical spatial lattice data set which has previously been analysed by a discrete time model involving unknown normalizing constants. We discuss the advantages and disadvantages of using continuous time processes compared...... with discrete time processes in the setting of the present paper as well as other spatial-temporal situations....

  9. Effects of snowmelt on watershed transit time distributions

    Science.gov (United States)

    Fang, Z.; Carroll, R. W. H.; Harman, C. J.; Wilusz, D. C.; Schumer, R.

    2017-12-01

    Snowmelt is the principal control of the timing and magnitude of water flow through alpine watersheds, but the streamflow generated may be displaced groundwater. To quantify this effect, we use a rank StorAge Selection (rSAS) model to estimate time-dependent travel time distributions (TTDs) for the East River Catchment (ERC, 84 km2) - a headwater basin of the Colorado River, and newly designated as the Lawrence Berkeley National Laboratory's Watershed Function Science Focus Area (SFA). Through the SFA, observational networks related to precipitation and stream fluxes have been established with a focus on environmental tracers and stable isotopes. The United Stated Geological Survey Precipitation Runoff Modeling System (PRMS) was used to estimate spatially- and temporally-variable boundary fluxes of effective precipitation (snowmelt & rain), evapotranspiration, and subsurface storage. The DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm was used to calibrate the rSAS model to observed stream isotopic concentration data and quantify uncertainty. The sensitivity of the simulated TTDs to systematic changes in the boundary fluxes was explored. Different PRMS and rSAS model parameters setup were tested to explore how they affect the relationship between input precipitation, especially snowmelt, and the estimated TTDs. Wavelet Coherence Analysis (WCA) was applied to investigate the seasonality of TTD simulations. Our ultimate goal is insight into how the Colorado River headwater catchments store and route water, and how sensitive flow paths and transit times are to climatic changes.

  10. Measurement of the residence time distribution in industrial flotation equipment

    International Nuclear Information System (INIS)

    Yianatos, Juan; Diaz, F; Rodriguez, Jorge

    2003-01-01

    This work presents a determination of the effective liquid and solid residence time in mechanical cell banks of primary and sweep flotation, and in cleaning flotation columns, at Codelco-Chile's Salvador Division. The determination was carried out using the residence time distribution (RTD) measurement with radioactive tracers. Br-82 was used as the trace element for the liquid. Different kinds of minerals were used to trace the solid: a) activated global tailing (non floatable), b) tailing activated by size classifications (non floatable) and c) activated floatable mineral. The residence time measurement defined effective volumes of 50-80% of the total volume in flotation cell banks, and effective volumes of 77% of the total volume of large-size flotation solids. The effective residence time of the solid (23%+212 microns) in industrial flotation cell banks was 5% below that for the liquid. The residence time of the mineral decreased with increased particle size. Thick mineral (>150 microns) showed a residence time 8% below that for thin mineral (<45 microns). The RTD of industrial mechanical cell banks is adequately represented with a number of perfect mixers in series equivalent to the number of real bank cells. The RTD of the industrial columns equals less than two perfect mixers in series and adjusts better when considering a perfect mixers in series model, but in a different size. Common operating problems could also be observed and analyzed through the RTD measurement, such as embankment of the equipment and the deficient regulation of the outflow, used to control the pulp level (Cw)

  11. Tool set for distributed real-time machine control

    Science.gov (United States)

    Carrott, Andrew J.; Wright, Christopher D.; West, Andrew A.; Harrison, Robert; Weston, Richard H.

    1997-01-01

    Demands for increased control capabilities require next generation manufacturing machines to comprise intelligent building elements, physically located at the point where the control functionality is required. Networks of modular intelligent controllers are increasingly designed into manufacturing machines and usable standards are slowly emerging. To implement a control system using off-the-shelf intelligent devices from multi-vendor sources requires a number of well defined activities, including (a) the specification and selection of interoperable control system components, (b) device independent application programming and (c) device configuration, management, monitoring and control. This paper briefly discusses the support for the above machine lifecycle activities through the development of an integrated computing environment populated with an extendable software toolset. The toolset supports machine builder activities such as initial control logic specification, logic analysis, machine modeling, mechanical verification, application programming, automatic code generation, simulation/test, version control, distributed run-time support and documentation. The environment itself consists of system management tools and a distributed object-oriented database which provides storage for the outputs from machine lifecycle activities and specific target control solutions.

  12. Indoor radon measurements in dwellings of Mizoram

    International Nuclear Information System (INIS)

    Lalramengzami, R.; Laldawngliana, C.; Sinha, D.; Ghosh, S.; Dwivedi, K.K.

    1995-01-01

    The concentration of indoor radon has been measured in some dwellings of Mizoram state by employing time integrated method using solid state nuclear track detector. This state is located in the north eastern region of India which has been identified as a high background area. The indoor radon levels determined in this work are compared with data obtained from other regions of India and the Environmental Protection Agency (EPA) prescribed safe limit. (author). 7 refs., 2 figs

  13. Distributed digital real-time control system for TCV tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Le, H.B. [École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Association EURATOM-Confédération Suisse, CH-1015 Lausanne (Switzerland); Felici, F. [Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Paley, J.I.; Duval, B.P.; Moret, J.-M.; Coda, S.; Sauter, O.; Fasel, D.; Marmillod, P. [École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Association EURATOM-Confédération Suisse, CH-1015 Lausanne (Switzerland)

    2014-03-15

    Highlights: • A new distributed digital control system for the TCV tokamak has been commissioned. • Data is shared in real-time between all nodes using the reflective memory. • The customised Linux OS allows achieving deterministic and low latency behaviour. • The control algorithm design in Simulink together with the automatic code generation using Embedded Coder allow rapid algorithm development. • Controllers designed outside the TCV environment can be ported easily. • The previous control system functions have been emulated and improved. • New capabilities include MHD control, profile control, equilibrium reconstruction. - Abstract: A new digital feedback control system (named the SCD “Système de Contrôle Distribué”) has been developed, integrated and used successfully to control TCV (Tokamak à Configuration Variable) plasmas. The system is designed to be modular, distributed, and scalable, accommodating hundreds of diagnostic inputs and actuator outputs. With many more inputs and outputs available than previously possible, it offers the possibility to design advanced control algorithms with better knowledge of the plasma state and to coherently control all TCV actuators, including poloidal field (PF) coils, gas valves, the gyrotron powers and launcher angles of the electron cyclotron heating and current drive system (ECRH/ECCD) together with diagnostic triggering signals. The system consists of multiple nodes; each is a customised Linux desktop or embedded PC which may have local ADC and DAC cards. Each node is also connected to a memory network (reflective memory) providing a reliable, deterministic method of sharing memory between all nodes. Control algorithms are programmed as block diagrams in Matlab-Simulink providing a powerful environment for modelling and control design. The C code is generated automatically from the Simulink block diagram and compiled, with the Simulink Embedded Coder (SEC, formerly Real-Time Workshop Embedded

  14. UK standards for exposure to radon daughters in dwellings

    International Nuclear Information System (INIS)

    Webb, G.A.M.; O'Riordan, M.C.

    1988-01-01

    The National Radiological Protection Board has issued formal advice on the standards to be adopted in the UK for control of exposures to radon daughters in existing dwellings and for changes in building procedures for future dwellings. The standards are based on those recommended by the International Commission on Radiological Protection but adapted to circumstances in the United Kingdom. The matters taken into account by the Board when formulating its advice include the conversion from measured concentrations of radon to effective dose equivalent and the implied levels of risk, the comparison of these levels with risks from other causes, the numbers of dwellings in which various annual doses are likely to be exceeded, the geographical distribution of these dwellings, the likely costs and effectiveness of various remedial measures and the degree of domestic disruption. The action level for existing dwellings selected by the Board was the same, 20 mSv per annum, as that recommended by the ICRP, but the upper bound for new dwellings of 5 mSv per annum was lower than that suggested by the ICRP

  15. UK standards for exposure to radon daughters in dwellings

    International Nuclear Information System (INIS)

    Webb, G.A.M.; O'Riordan, M.C.

    1988-01-01

    The National Radiological Protection Board has issued formal advice on the standards to be adopted in the UK for control of exposures to radon daughters in existing dwellings and for changes in building procedures for future dwellings. The standards are based on those recommended by the international commission on radiological protection but adapted to circumstances in the United Kingdom. The matters taken into account by the Board when formulating its advice, and which are discussed in the paper, include the conversion from measured concentrations of radon to effective dose equivalent and the implied levels of risk, the comparison of these levels with risks from other causes, the numbers of dwellings in which various annual doses are likely to be exceeded, the geographical distribution of these dwellings, the likely costs and effectiveness of various remedial measures and the degree of domestic disruption. The action level for existing dwellings selected by the Board was the same, 20 mSv per annum, as that recommended by the ICRP, but the upper bound for new dwellings of 5 mSv per annum was lower than that suggested by the ICRP [fr

  16. Cost effectiveness of reducing radon exposure in Spanish dwellings

    International Nuclear Information System (INIS)

    Colgan, P.A.; Gutierrez, J.

    1996-01-01

    Published information on the distribution of radon levels in Spanish single family dwellings is used to evaluate the cost-effectiveness of three different intervention scenarios: remediation of existing dwellings, radon proofing of all future dwellings and the targetting of areas with higher than average indoor radon concentrations. Analysis is carried out on the basis of a Reference Level of 400 Bq m -3 for the existing housing stock and 200 Bq m -3 for new dwellings. Certain assumptions are made about the effectiveness and durability of the measures applied and annualised costs are used to calculate the costs per lung cancer death averted. The results reveal that targetting future housing is a more cost-effective option than remediation of existing dwellings with radon concentrations above the Reference Level -the costs per lung cancer death averted are typically $145000. In high-risk areas, these costs can be considerably less, depending on the percentage of dwellings expected to exceed the Reference Level and the average savings in exposure as a result of the intervention. The costs of intervention to reduce lung cancer deaths following exposure to radon compare favourably with those of other health programmes in other countries. (Author)

  17. 12 CFR 541.10 - Dwelling unit.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Dwelling unit. 541.10 Section 541.10 Banks and... FEDERAL SAVINGS ASSOCIATIONS § 541.10 Dwelling unit. The term dwelling unit means the unified combination of rooms designed for residential use by one family, other than a single-family dwelling. ...

  18. 7 CFR 3550.106 - Dwelling requirements.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Dwelling requirements. 3550.106 Section 3550.106... Waste Disposal Grants § 3550.106 Dwelling requirements. (a) Modest dwelling. The property must be one... § 3550.63. (b) Post-repair condition. Dwellings repaired with section 504 funds need not be brought to...

  19. Association of fall history with the Timed Up and Go test score and the dual task cost: A cross-sectional study among independent community-dwelling older adults.

    Science.gov (United States)

    Asai, Tsuyoshi; Oshima, Kensuke; Fukumoto, Yoshihiro; Yonezawa, Yuri; Matsuo, Asuka; Misu, Shogo

    2018-05-21

    To investigate the associations between fall history and the Timed Up and Go (TUG) test (single-TUG test), TUG test while counting aloud backwards from 100 (dual-TUG test) and the dual-task cost (DTC) among independent community-dwelling older adults. This cross-sectional study included 537 older adults who lived independently in the community. Data on fall history in the previous year were obtained by self-administrated questionnaire. The single- and dual-TUG tests were carried out, and the DTC value was computed from these results. Associations between fall history and these TUG-related values were analyzed using multivariate logistic regression models. The participants were divided into fall risk groups using the cut-off values of those significantly associated with falling, and the odds ratios (OR) were computed. Slower single-TUG test scores and lower DTC values were significantly associated with fall history after adjusting for potential confounders (single-TUG test score: OR 1.133, 95% CI 1.029-1.249; DTC value: OR 0.984, 95% CI 0.968-0.998). Older adults with slower single-TUG test scores and lower DTC values reported a fall history more often than those in other categories (OR compared with the lower-risk single-TUG and lower-risk DTC groups: 3.474, 95% CI 1.881-6.570). Slower single-TUG test scores and lower DTC values are associated with fall history among independent community-dwelling older adults. To some extent, dual task performance might provide added value for fall assessment, compared with administering the TUG test alone. Geriatr Gerontol Int 2018; ••: ••-••. © 2018 Japan Geriatrics Society.

  20. Factors Influencing Dwell Fatigue Cracking in Notches of Powder Metallurgy Superalloys

    Science.gov (United States)

    Gabb, T. P.; Telesman, J.; Ghosn, L.; Garg, A.; Gayda, J.

    2011-01-01

    The influences of heat treatment and cyclic dwells on the notch fatigue resistance of powder metallurgy disk superalloys were investigated for low solvus high refractory (LSHR) and ME3 disk alloys. Disks were processed to produce material conditions with varied microstructures and associated mechanical properties. Notched specimens were first subjected to baseline dwell fatigue cycles having a dwell at maximum load, as well as tensile, stress relaxation, creep rupture, and dwell fatigue crack growth tests at 704 C. Several material heat treatments displayed a bimodal distribution of fatigue life with the lives varying by two orders-of-magnitude, while others had more consistent fatigue lives. This response was compared to other mechanical properties, in search of correlations. The wide scatter in baseline dwell fatigue life was observed only for material conditions resistant to stress relaxation. For selected materials and conditions, additional tests were then performed with the dwells shifted in part or in total to minimum tensile load. The tests performed with dwells at minimum load exhibited lower fatigue lives than max dwell tests, and also exhibited early crack initiation and a substantial increase in the number of initiation sites. These results could be explained in part by modeling evolution of peak stresses in the notch with continued dwell fatigue cycling. Fatigue-environment interactions were determined to limit life for the fatigue cycles with dwells.

  1. Software Architecture for Distributed Real-Time Embedded Systems

    National Research Council Canada - National Science Library

    Almeida, Jose

    1998-01-01

    .... This thesis focuses on the distributed scheduling problem. It proposes a distributed scheduling algorithm to allocate and schedule a set of tasks onto a collection of processors linked by a network...

  2. Radon in dwellings in Sweden

    International Nuclear Information System (INIS)

    Swedjemark, G.A.

    1980-01-01

    Studies on specific activities in building materials, gamma-radiation levels in dwellings, the concentrations of radon and daughters in the air indoors and the concentration of radon in tap water are in progress in Sweden. On the basis of these investigations and of the investigation of Hultqvist from the beginning of the 1950's, an attempt has been made to show how the radiation doses in dwellings have changed or may be changed by human activities and what these changes imply in terms of collective dose. The annual collective absorbed dose in the basal cells of the critical bronchial region have increased from 11 x 10 3 man-Gy for the occupants of dwellings existing in 1950 to 25 x 10 3 man-Gy for dwellings existing in 1975

  3. 25 CFR 256.15 - How long will I have to wait for repair, renovation, or replacement of my dwelling?

    Science.gov (United States)

    2010-04-01

    ... replacement of my dwelling? 256.15 Section 256.15 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR... replacement of my dwelling? The length of time that it takes to accomplish the work to be done on your dwelling is dependent on: (a) Whether funds are available; (b) The type of work to be done; (c) The climate...

  4. Temporal Architecture: Poetic Dwelling in Japanese buildings

    Directory of Open Access Journals (Sweden)

    Michael Lazarin

    2014-07-01

    Full Text Available Heidegger’s thinking about poetic dwelling and Derrida’s impressions of Freudian estrangement are employed to provide a constitutional analysis of the experience of Japanese architecture, in particular, the Japanese vestibule (genkan. This analysis is supplemented by writings by Japanese architects and poets. The principal elements of Japanese architecture are: (1 ma, and (2 en. Ma is usually translated as ‘interval’ because, like the English word, it applies to both space and time.  However, in Japanese thinking, it is not so much an either/or, but rather a both/and. In other words, Japanese architecture emphasises the temporal aspect of dwelling in a way that Western architectural thinking usually does not. En means ‘joint, edge, the in-between’ as an ambiguous, often asymmetrical spanning of interior and exterior, rather than a demarcation of these regions. Both elements are aimed at producing an experience of temporality and transiency.

  5. Timing Analysis of Mixed-Criticality Hard Real-Time Applications Implemented on Distributed Partitioned Architectures

    DEFF Research Database (Denmark)

    Marinescu, Sorin Ovidiu; Tamas-Selicean, Domitian; Acretoaie, Vlad

    In this paper we are interested in the timing analysis of mixed-criticality embedded real-time applications mapped on distributed heterogeneous architectures. Mixedcriticality tasks can be integrated onto the same architecture only if there is enough spatial and temporal separation among them. We...... in partitions using fixedpriority preemptive scheduling. We have extended the stateof- the-art algorithms for schedulability analysis to take into account the partitions. The proposed algorithm has been evaluated using several synthetic and real-life benchmarks....... consider that the separation is provided by partitioning, such that applications run in separate partitions, and each partition is allocated several time slots on a processor. Each partition can have its own scheduling policy. We are interested to determine the worst-case response times of tasks scheduled...

  6. LPI Radar Waveform Recognition Based on Time-Frequency Distribution

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2016-10-01

    Full Text Available In this paper, an automatic radar waveform recognition system in a high noise environment is proposed. Signal waveform recognition techniques are widely applied in the field of cognitive radio, spectrum management and radar applications, etc. We devise a system to classify the modulating signals widely used in low probability of intercept (LPI radar detection systems. The radar signals are divided into eight types of classifications, including linear frequency modulation (LFM, BPSK (Barker code modulation, Costas codes and polyphase codes (comprising Frank, P1, P2, P3 and P4. The classifier is Elman neural network (ENN, and it is a supervised classification based on features extracted from the system. Through the techniques of image filtering, image opening operation, skeleton extraction, principal component analysis (PCA, image binarization algorithm and Pseudo–Zernike moments, etc., the features are extracted from the Choi–Williams time-frequency distribution (CWD image of the received data. In order to reduce the redundant features and simplify calculation, the features selection algorithm based on mutual information between classes and features vectors are applied. The superiority of the proposed classification system is demonstrated by the simulations and analysis. Simulation results show that the overall ratio of successful recognition (RSR is 94.7% at signal-to-noise ratio (SNR of −2 dB.

  7. Cybersecurity through Real-Time Distributed Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kisner, Roger A [ORNL; Manges, Wayne W [ORNL; MacIntyre, Lawrence Paul [ORNL; Nutaro, James J [ORNL; Munro Jr, John K [ORNL; Ewing, Paul D [ORNL; Howlader, Mostofa [ORNL; Kuruganti, Phani Teja [ORNL; Wallace, Richard M [ORNL; Olama, Mohammed M [ORNL

    2010-04-01

    Critical infrastructure sites and facilities are becoming increasingly dependent on interconnected physical and cyber-based real-time distributed control systems (RTDCSs). A mounting cybersecurity threat results from the nature of these ubiquitous and sometimes unrestrained communications interconnections. Much work is under way in numerous organizations to characterize the cyber threat, determine means to minimize risk, and develop mitigation strategies to address potential consequences. While it seems natural that a simple application of cyber-protection methods derived from corporate business information technology (IT) domain would lead to an acceptable solution, the reality is that the characteristics of RTDCSs make many of those methods inadequate and unsatisfactory or even harmful. A solution lies in developing a defense-in-depth approach that ranges from protection at communications interconnect levels ultimately to the control system s functional characteristics that are designed to maintain control in the face of malicious intrusion. This paper summarizes the nature of RTDCSs from a cybersecurity perspec tive and discusses issues, vulnerabilities, candidate mitigation approaches, and metrics.

  8. Estimation Accuracy on Execution Time of Run-Time Tasks in a Heterogeneous Distributed Environment

    Directory of Open Access Journals (Sweden)

    Qi Liu

    2016-08-01

    Full Text Available Distributed Computing has achieved tremendous development since cloud computing was proposed in 2006, and played a vital role promoting rapid growth of data collecting and analysis models, e.g., Internet of things, Cyber-Physical Systems, Big Data Analytics, etc. Hadoop has become a data convergence platform for sensor networks. As one of the core components, MapReduce facilitates allocating, processing and mining of collected large-scale data, where speculative execution strategies help solve straggler problems. However, there is still no efficient solution for accurate estimation on execution time of run-time tasks, which can affect task allocation and distribution in MapReduce. In this paper, task execution data have been collected and employed for the estimation. A two-phase regression (TPR method is proposed to predict the finishing time of each task accurately. Detailed data of each task have drawn interests with detailed analysis report being made. According to the results, the prediction accuracy of concurrent tasks’ execution time can be improved, in particular for some regular jobs.

  9. The Marginal Distributions of a Crossing Time and Renewal Numbers Related with Two Poisson Processes are as Ph-Distributions

    Directory of Open Access Journals (Sweden)

    Mir G. H. Talpur

    2006-01-01

    Full Text Available In this paper we consider, how to find the marginal distributions of crossing time and renewal numbers related with two poisson processes by using probability arguments. The obtained results show that the one-dimension marginal distributions are N+1 order PH-distributions.

  10. Time synchronization algorithm of distributed system based on server time-revise and workstation self-adjust

    International Nuclear Information System (INIS)

    Zhou Shumin; Sun Yamin; Tang Bin

    2007-01-01

    In order to enhance the time synchronization quality of the distributed system, a time synchronization algorithm of distributed system based on server time-revise and workstation self-adjust is proposed. The time-revise cycle and self-adjust process is introduced in the paper. The algorithm reduces network flow effectively and enhances the quality of clock-synchronization. (authors)

  11. Unidata Internet Data Distribution (IDD) and THematic Real-time Environmental Distributed Data Services (THREDDS)

    Science.gov (United States)

    Domenico, B.

    2001-12-01

    Universities across the nation are transforming their teaching and research efforts through increased use of a rapidly expanding menu of environmental data. With funding from the Division of Atmospheric Sciences (ATM ) of the National Science Foundation (NSF), the Unidata Program is playing a central role in this transformation by enabling universities to employ innovative computing and networking technologies to acquire such data sets in real-time and use them routinely in their classrooms and research labs. Working with the Unidata Program Center (UPC), the Unidata community, comprising over 140 departments, has built a national Internet Data Distribution (IDD ) system. The IDD allows users to "subscribe" to certain sets of data products; IDD servers then deliver the requested data to their local servers as soon as they are available from the source. With the initial national implementation in 1994, the IDD may have been the original example of Internet "push" technology. It now provides the reliability, flexibility, and efficiency required by participating institutions. As the underlying Internet technology evolves, we anticipate dramatic increases in the volume of data delivered. We plan to augment the system to better serve disciplines outside the atmospheric sciences and to incorporate anticipated new networking technologies to minimize the impact of the IDD on the underlying network. Unidata has recently undertaken a new initiative called THREDDS (THematic Real-time Environmental Distributed Data Services) under a grant from the NSF Division of Undergraduate Education NSDL (National Science, Math, Engineering, Technology Education Digital Library). The goal of THREDDs is to make it possible for students, educators and researchers to publish, contribute, find, and interact with data relating to the Earth system in a convenient, effective, and integrated fashion. Just as the World Wide Web and digital-library technologies have simplified the process of

  12. NCU-SWIP Space Weather Instrumentation Payload - Intelligent Sensors On Efficient Real-Time Distributed LUTOS

    Science.gov (United States)

    Yeh, Tse-Liang; Dmitriev, Alexei; Chu, Yen-Hsyang; Jiang, Shyh-Biau; Chen, Li-Wu

    The NCU-SWIP - Space Weather Instrumentation Payload is developed for simultaneous in-situ and remote measurement of space weather parameters for cross verifications. The measurements include in-situ electron density, electron temperature, magnetic field, the deceleration of satellite due to neutral wind, and remotely the linear cumulative intensities of oxygen ion air-glows at 135.6nm and 630.0nm along the flight path in forward, nader, and backward directions for tomographic reconstruction of the electron density distribution underneath. This instrument package is suitable for micro satellite constellation to establish nominal space weather profiles and, thus, to detect abnormal variations as the signs of ionospheric disturbances induced by severe atmospheric weather, or earth quake - mantle movement through their Lithosphere-Atmosphere-Ionosphere Coupling Mechanism. NCU-SWIP is constructed with intelligent sensor modules connected by common bus with their functionalities managed by an efficient distributed real-time system LUTOS. The same hierarchy can be applied to the level of satellite constellation. For example SWIP's in a constellation in coordination with the GNSS Occultation Experiment TriG planned for the Formosa-7 constellation, data can be cross correlated for verification and refinement for real-time, stable and reliable measurements. A SWIP will be contributed to the construction of a MAI Micro Satellite for verification. The SWIP consists of two separate modules: the SWIP main control module and the SWIP-PMTomo sensor module. They are respectively a 1.5kg W120xL120xH100 (in mm) box with forward facing 120mmPhi circular disk probe on a boom top edged at 470mm height and a 7.2kg W126xL590x372H (in mm) slab containing 3 legs looking downwards along the flight path, while consuming the maximum electricity of 10W and 12W. The sensors are 1) ETPEDP measuring 16bits floating potentials for electron temperature range of 1000K to 3000K and 24bits electron

  13. An affordable proxy of representative national survey on radon concentration in dwellings: Design, organisation and preliminary evaluation of representativeness

    International Nuclear Information System (INIS)

    Antignani, Sara; Carelli, Vinicio; Cordedda, Carlo; Zonno, Fedele; Ampollini, Marco; Carpentieri, Carmela; Venoso, Gennaro; Bochicchio, Francesco

    2013-01-01

    Representative national surveys in dwellings are important to unbiasedly evaluate the exposure of the general population to radon. In Italy, a representative national survey was conducted from 1989 to 1996, which involved about 5600 dwellings in 232 towns. Later on, some Regions carried out more detailed surveys, but a new national survey in dwellings is necessary in order to obtain a more thorough estimate of radon concentration distribution over the Italian territory. The need to make this survey in an affordable way led to implement a new approach based on the collaboration between the Istituto Superiore di Sanità and a national company with workplaces and employees' homes throughout the country. The intent is to carry out a proxy of a population representative survey by measuring radon concentration in the homes of a random sample of the company employees. The realisation of this survey was affordable, thanks to the availability of corporate e-mail for each employee, intranet service, and company internal mail service. A dedicated web procedure and e-questionnaires allowed to automatically manage the contact with employees and to collect their data, which were both cost- and time-saving. Using this e-mail contact approach, 53% of contacted employees consented to participate in the survey. Radon concentration passive measuring devices were distributed to about 7000 dwellings, using about 14000 CR-39 detectors (two measured rooms per dwelling). In order to reduce costs, the devices were exposed for 12 months instead of two consecutive 6-month periods (as with the former national survey). A first checking of the actual representativeness of the sample was done by comparing characteristics of dwellings and occupants in the sample with corresponding data from the latest National Census. This was accomplished thanks to the fact that the questions in the survey questionnaire were tailored to the categories adopted for the Census questionnaire. A preliminary

  14. Associations of sedentary time and moderate-vigorous physical activity with sleep-disordered breathing and polysomnographic sleep in community-dwelling adults.

    Science.gov (United States)

    Kline, Christopher E; Krafty, Robert T; Mulukutla, Suresh; Hall, Martica H

    2017-05-01

    The purpose of this study was to evaluate the relationship between daytime activity (sedentary time, moderate- to vigorous-intensity physical activity [MVPA]) and indices of polysomnographically (PSG) assessed sleep, including sleep-disordered breathing (SDB). One hundred and thirty-six adults (65% female, 59.8 ± 9.1 years, body mass index [BMI] 30.3 ± 6.9 kg m -2 ) provided daily estimates of time spent in light-, moderate-, and vigorous-intensity activity for 6-14 days (mean 9.9 ± 1.8 days) prior to laboratory PSG. Daily sedentary time was calculated as the amount of time spent awake and not in light-, moderate-, or vigorous-intensity activity; time spent in moderate- and vigorous-intensity activity were combined for MVPA. Indices of PSG sleep included timing (sleep midpoint), duration (total sleep time), continuity (sleep efficiency), depth (% slow-wave sleep), and SDB (apnea-hypopnea index [AHI]). Using median splits of sedentary time and MVPA, analyses of covariance examined their relationship with sleep following adjustment for age, sex, race, employment, education, BMI, existing cardiovascular disease, depression history, and mean daily wake time. Binary logistic regression examined the odds of having at least mild-severity SDB (AHI ≥ 5) according to sedentary time, MVPA, and their combination. Adults with above-median sedentary time (i.e., >841.9 min/day) had significantly greater AHI (P = .04) and lower odds of mild SDB (P = .03) compared to adults with low sedentary time; adults with high MVPA (>30.5 min/day) had significantly lower AHI compared to adults with low MVPA (P = .04). When examined in the same model, adults with high sedentary time and low MVPA had significantly higher AHI (P < .01) and higher odds of having mild SDB (P = .03) than all the other groups. No other sleep measures were related to sedentary time, MVPA, or their combination. Sedentary time and MVPA were associated with SDB. Whether reducing sedentary

  15. Radon in dwellings in Sweden

    International Nuclear Information System (INIS)

    Swedjemark, G.A.

    1978-04-01

    Studies on the specific activities in building materials, the γ-radiation levels in dwellings, the concentrations of radon and daughters in the air indoors and the concentration of radon in tap water are in progress in Sweden. On basis of these investigations and of the investigation of Hultqvist from the beginning of the 1950s, an attempt has been made to show how the radiation doses in dwellings have changed or may be changed by human activities and what these changes imply in terms of collective dose. The annual collective absorbed dose in the basal cells of the critical bronchial region have increased from 11 . 10 3 manGy for the occupants of dwellings existing in 1950 to 25 . 10 3 manGy for dwellings existing in 1975. If the building of houses continues as at present it can be estimated that the annual collective dose will be between 25 and 31 . 10 3 manGy for the dwellings of 1985. (author)

  16. Time-frequency distributions for propulsion-system diagnostics

    Science.gov (United States)

    Griffin, Michael E.; Tulpule, Sharayu

    1991-12-01

    The Wigner distribution and its smoothed versions, i.e., Choi-Williams and Gaussian kernels, are evaluated for propulsion system diagnostics. The approach is intended for off-line kernel design by using the ambiguity domain to select the appropriate Gaussian kernel. The features produced by the Wigner distribution and its smoothed versions correlate remarkably well with documented failure indications. The selection of the kernel on the other hand is very subjective for our unstructured data.

  17. Migrating to a real-time distributed parallel simulator architecture- An update

    CSIR Research Space (South Africa)

    Duvenhage, B

    2007-09-01

    Full Text Available A legacy non-distributed logical time simulator was previously migrated to a distributed architecture to parallelise execution. The existing Discrete Time System Specification (DTSS) modelling formalism was retained to simplify the reuse of existing...

  18. The spectrum of worry in the community-dwelling elderly.

    LENUS (Irish Health Repository)

    Golden, Jeannette

    2011-11-01

    In this study, we examine the prevalence and distribution of worry, its content, and its associations with quality of life and depression, based on a large sample of community-dwelling elderly. We will attempt to distinguish between pathological and non-pathological worry based on these associations.

  19. A Metrics-Based Approach to Intrusion Detection System Evaluation for Distributed Real-Time Systems

    Science.gov (United States)

    2002-04-01

    Based Approach to Intrusion Detection System Evaluation for Distributed Real - Time Systems Authors: G. A. Fink, B. L. Chappell, T. G. Turner, and...Distributed, Security. 1 Introduction Processing and cost requirements are driving future naval combat platforms to use distributed, real - time systems of...distributed, real - time systems . As these systems grow more complex, the timing requirements do not diminish; indeed, they may become more constrained

  20. A Formal Approach to Run-Time Evaluation of Real-Time Behaviour in Distributed Process Control Systems

    DEFF Research Database (Denmark)

    Kristensen, C.H.

    This thesis advocates a formal approach to run-time evaluation of real-time behaviour in distributed process sontrol systems, motivated by a growing interest in applying the increasingly popular formal methods in the application area of distributed process control systems. We propose to evaluate...... because the real-time aspects of distributed process control systems are considered to be among the hardest and most interesting to handle....

  1. Deepwater Horizon - Estimating surface oil volume distribution in real time

    Science.gov (United States)

    Lehr, B.; Simecek-Beatty, D.; Leifer, I.

    2011-12-01

    Spill responders to the Deepwater Horizon (DWH) oil spill required both the relative spatial distribution and total oil volume of the surface oil. The former was needed on a daily basis to plan and direct local surface recovery and treatment operations. The latter was needed less frequently to provide information for strategic response planning. Unfortunately, the standard spill observation methods were inadequate for an oil spill this size, and new, experimental, methods, were not ready to meet the operational demands of near real-time results. Traditional surface oil estimation tools for large spills include satellite-based sensors to define the spatial extent (but not thickness) of the oil, complemented with trained observers in small aircraft, sometimes supplemented by active or passive remote sensing equipment, to determine surface percent coverage of the 'thick' part of the slick, where the vast majority of the surface oil exists. These tools were also applied to DWH in the early days of the spill but the shear size of the spill prevented synoptic information of the surface slick through the use small aircraft. Also, satellite images of the spill, while large in number, varied considerably in image quality, requiring skilled interpretation of them to identify oil and eliminate false positives. Qualified staff to perform this task were soon in short supply. However, large spills are often events that overcome organizational inertia to the use of new technology. Two prime examples in DWH were the application of hyper-spectral scans from a high-altitude aircraft and more traditional fixed-wing aircraft using multi-spectral scans processed by use of a neural network to determine, respectively, absolute or relative oil thickness. But, with new technology, come new challenges. The hyper-spectral instrument required special viewing conditions that were not present on a daily basis and analysis infrastructure to process the data that was not available at the command

  2. Simplified hourly method to calculate summer temperatures in dwellings

    DEFF Research Database (Denmark)

    Mortensen, Lone Hedegaard; Aggerholm, Søren

    2012-01-01

    with an ordinary distribution of windows and a “worst” case where the window area facing south and west was increased by more than 60%. The simplified method used Danish weather data and only needs information on transmission losses, thermal mass, surface contact, internal load, ventilation scheme and solar load...... program for thermal simulations of buildings. The results are based on one year simulations of two cases. The cases were based on a low energy dwelling of 196 m². The transmission loss for the building envelope was 3.3 W/m², not including windows and doors. The dwelling was tested in two cases, a case...

  3. Real-Time Optimization and Control of Next-Generation Distribution

    Science.gov (United States)

    -Generation Distribution Infrastructure Real-Time Optimization and Control of Next-Generation Distribution developing a system-theoretic distribution network management framework that unifies real-time voltage and Infrastructure | Grid Modernization | NREL Real-Time Optimization and Control of Next

  4. Ioffe-time distributions instead of parton momentum distributions in description of deep inelastic scattering

    International Nuclear Information System (INIS)

    Braun, V.; Gornicki, P.; Mankiewicz, L.

    1994-10-01

    We argue that parton distributions in coordinate space provide a more natural object for nonperturbative methods compared to the usual momentum distributions in which the physics of different longitudinal distances is being mixed. To illustrate the advantages of the coordinate space formulation, we calculate the coordinate space distributions for valence quarks in the proton using the QCD sum rule approach. A remarkable agreement is found between the calcuulated and the experimentally measured u-quark distribution up to distances of order ∝2 fm in the proton rest frame. The standard calculation completely fails, however, for valence d quarks; the reasons for this discrepancy are discussed. (orig.)

  5. Just-in-time Data Distribution for Analytical Query Processing

    NARCIS (Netherlands)

    M.G. Ivanova (Milena); M.L. Kersten (Martin); F.E. Groffen (Fabian)

    2012-01-01

    textabstract Distributed processing commonly requires data spread across machines using a priori static or hash-based data allocation. In this paper, we explore an alternative approach that starts from a master node in control of the complete database, and a variable number of worker nodes

  6. Sharing Real-Time Objects in Distributed Embedded Systems

    DEFF Research Database (Denmark)

    Larsen, Erland Ketil; Havn, Ib

    2015-01-01

    microcontrollers connected by a RS-485 bus. The demo system shows that it is relatively simple to implement a distributed embedded system with the provided API, and the latency of the communication service is predictable. A low coupling to hardware makes it easy to port to another platform and/or another network...

  7. Liver allocation and distribution: time for a change.

    Science.gov (United States)

    Deshpande, Ranjit; Hirose, Ryutaro; Mulligan, David

    2017-04-01

    Liver allograft allocation has been a topic of hot debate for over a decade. New redistricting changes have been proposed by the Liver and Intestinal Transplant Committee to the existing United Network for Organ Sharing (UNOS) liver allocation policy. The basis of this new proposal is similar to the old one with an aim to distribute organs in a fair, efficient and equitable fashion. In this review, we plan to look in depth at the redistribution proposals thus far, their merits and how they may help patients who do not have adequate access to livers. Many authors have criticized the proposed changes to organ distribution to reduce geographic disparity in access to liver transplantation. Our focus in this article is to bring forth the most recent literature and proposed changes in the current distribution system. We will also mention two other possible methods that have been proposed to redesign distribution using concentric circles and neighborhoods. In this article, we also look at the economics of the redistricting proposal and its effects on transplant centers. The UNOS Liver and Intestinal Transplant Committee has recommended a proposal using the eight-district model with proximity circles and three additional Model for End-Stage Liver Disease (MELD) points with initial sharing MELD threshold of 25 as a starting point to reduce disparity in patient access to deceased donor livers for transplantation. This proposal has met with significant resistance because of concerns of cost, logistics and impact on existing transplant centers. Other methodologies have also been proposed that have the potential to significantly improve our current disparity of access to life-saving organs. Variation in the supply of donor organs vs. the demand or need for liver transplant by geography and the current defined areas of distribution drive this disparity. Cost benefits to the healthcare system in caring for patients with advanced stages of liver disease may outweigh increased

  8. Bimodal Formation Time Distribution for Infall Dark Matter Halos

    Science.gov (United States)

    Shi, Jingjing; Wang, Huiyuan; Mo, H. J.; Xie, Lizhi; Wang, Xiaoyu; Lapi, Andrea; Sheth, Ravi K.

    2018-04-01

    We use a 200 {h}-1 {Mpc} a-side N-body simulation to study the mass accretion history (MAH) of dark matter halos to be accreted by larger halos, which we call infall halos. We define a quantity {a}nf}\\equiv (1+{z}{{f}})/(1+{z}peak}) to characterize the MAH of infall halos, where {z}peak} and {z}{{f}} are the accretion and formation redshifts, respectively. We find that, at given {z}peak}, their MAH is bimodal. Infall halos are dominated by a young population at high redshift and by an old population at low redshift. For the young population, the {a}nf} distribution is narrow and peaks at about 1.2, independent of {z}peak}, while for the old population, the peak position and width of the {a}nf} distribution both increase with decreasing {z}peak} and are both larger than those of the young population. This bimodal distribution is found to be closely connected to the two phases in the MAHs of halos. While members of the young population are still in the fast accretion phase at z peak, those of the old population have already entered the slow accretion phase at {z}peak}. This bimodal distribution is not found for the whole halo population, nor is it seen in halo merger trees generated with the extended Press–Schechter formalism. The infall halo population at {z}peak} are, on average, younger than the whole halo population of similar masses identified at the same redshift. We discuss the implications of our findings in connection to the bimodal color distribution of observed galaxies and to the link between central and satellite galaxies.

  9. Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks

    OpenAIRE

    Chaoyang Shi; Bi Yu Chen; William H. K. Lam; Qingquan Li

    2017-01-01

    Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are f...

  10. Observation of lateral substructures in EAS by measurement of the time distribution of atmospheric Cerenkov light

    International Nuclear Information System (INIS)

    Bosia, G.; Navarra, G.; Saavedra, O.

    1975-01-01

    The lateral structure of EAS is derived from the arrival time distribution of atmospheric Cerenkov light assuming a strict correlation between time structure and lateral particle distribution. Results of the Pic du Midi experiment are presented. Substructures in the time distribution of the Cerenkov light can be related to structures in the lateral density distribution of electrons. The frequency (a few %) of substructures can be explained within conventional models of high energy interactions. (orig.) [de

  11. Interdependence of environmental parameters and sand dwelling benthic species abundance: a multivariate approach

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Parulekar, A.H.

    Multivariate analysis showed dependence of distribution and abundance of sand dwelling fauna on more than one ecologically significant environmental parameters rather than one ecological master factor. Salinity, grain size, beach gradient, dissolved...

  12. Resolving runaway electron distributions in space, time, and energy

    Science.gov (United States)

    Paz-Soldan, C.; Cooper, C. M.; Aleynikov, P.; Eidietis, N. W.; Lvovskiy, A.; Pace, D. C.; Brennan, D. P.; Hollmann, E. M.; Liu, C.; Moyer, R. A.; Shiraki, D.

    2018-05-01

    Areas of agreement and disagreement with present-day models of runaway electron (RE) evolution are revealed by measuring MeV-level bremsstrahlung radiation from runaway electrons (REs) with a pinhole camera. Spatially resolved measurements localize the RE beam, reveal energy-dependent RE transport, and can be used to perform full two-dimensional (energy and pitch-angle) inversions of the RE phase-space distribution. Energy-resolved measurements find qualitative agreement with modeling on the role of collisional and synchrotron damping in modifying the RE distribution shape. Measurements are consistent with predictions of phase-space attractors that accumulate REs, with non-monotonic features observed in the distribution. Temporally resolved measurements find qualitative agreement with modeling on the impact of collisional and synchrotron damping in varying the RE growth and decay rate. Anomalous RE loss is observed and found to be largest at low energy. Possible roles for kinetic instability or spatial transport to resolve these anomalies are discussed.

  13. 7 CFR 3550.57 - Dwelling requirements.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Dwelling requirements. 3550.57 Section 3550.57... AGRICULTURE DIRECT SINGLE FAMILY HOUSING LOANS AND GRANTS Section 502 Origination § 3550.57 Dwelling requirements. (a) Modest dwelling. The property must be one that is considered modest for the area, must not be...

  14. Real-time Distributed Economic Dispatch forDistributed Generation Based on Multi-Agent System

    DEFF Research Database (Denmark)

    Luo, Kui; Wu, Qiuwei; Nielsen, Arne Hejde

    2015-01-01

    The distributed economic dispatch for distributed generation is formulated as a optimization problem with equality and inequality constraints. An effective distributed approach based on multi-agent system is proposed for solving the economic dispatch problem in this paper. The proposed approach...... consists of two stages. In the first stage, an adjacency average allocation algorithm is proposed to ensure the generation-demand equality. In the second stage, a local replicator dynamics algorithm is applied to achieve nash equilibrium for the power dispatch game. The approach is implemented in a fully...

  15. Indoor environmental quality in French dwellings and building characteristics

    Science.gov (United States)

    Langer, Sarka; Ramalho, Olivier; Derbez, Mickaël; Ribéron, Jacques; Kirchner, Severine; Mandin, Corinne

    2016-03-01

    A national survey on indoor environmental quality covering 567 residences in mainland France was performed during 2003-2005. The measured parameters were temperature, relative humidity, CO2, and the indoor air pollutants: fourteen individual volatile organic compounds (VOC), four aldehydes and particulate matter PM10 and PM2.5. The measured indoor concentrations were analyzed for correlations with the building characteristics: type of dwelling, period of construction, dwelling location, type of ventilation system, building material, attached garage and retrofitting. The median night time air exchange rate (AER) for all dwellings was 0.44 h-1. The night time AER was higher in apartments (median = 0.49 h-1) than in single-family houses (median = 0.41 h-1). Concentration of formaldehyde was approximately 30% higher in dwellings built after 1990 compared with older ones; it was higher in dwellings with mechanical ventilation and in concrete buildings. The VOC concentrations depended on the building characteristics to various extents. The sampling season influenced the majority of the indoor climate parameters and the concentrations of the air pollutants to a higher degree than the building characteristics. Multivariate linear regression models revealed that the indoor-outdoor difference in specific humidity, a proxy for number of occupants and their indoor activities, remained a significant predictor for most gaseous and particulate air pollutants. The other strong predictors were outdoor concentration, smoking, attached garage and AER (in descending order).

  16. Dwelling towers of Czech castles

    Czech Academy of Sciences Publication Activity Database

    Durdík, Tomáš

    2009-01-01

    Roč. 63, - (2009), s. 139-150 ISSN 1875-2896. [Meeting of Europa Nostra Scientific Council /44./. Kilkenny, 27.09.2008-02.10.2008] Institutional research plan: CEZ:AV0Z80020508 Keywords : castle * castellology * dwelling tower * donjon * keep * medieval archaeology * architecture * Bohemia * Middle Ages Subject RIV: AC - Archeology, Anthropology, Ethnology

  17. Particle transport in urban dwellings

    International Nuclear Information System (INIS)

    Cannell, R.J.; Goddard, A.J.H.; ApSimon, H.M.

    1988-01-01

    A quantitative investigation of the potential for contamination of a dwelling by material carried in on the occupants' footwear has been completed. Data are now available on the transport capacity of different footwear for a small range of particle sizes and contamination source strengths. Additional information is also given on the rate of redistribution

  18. Executive functioning independently predicts self-rated health and improvement in self-rated health over time among community-dwelling older adults.

    Science.gov (United States)

    McHugh, Joanna Edel; Lawlor, Brian A

    2016-01-01

    Self-rated health, as distinct from objective measures of health, is a clinically informative metric among older adults. The purpose of our study was to examine the cognitive and psychosocial factors associated with self-rated health. 624 participants over the age of 60 were assessed at baseline, and of these, 510 were contacted for a follow-up two years later. Measures of executive function and self-rated health were assessed at baseline, and self-rated health was assessed at follow-up. We employed multiple linear regression analyses to investigate the relationship between executive functioning and self-rated health, while controlling for demographic, psychosocial and biological variables. Controlling for other relevant variables, executive functioning independently and solely predicted self-rated health, both at a cross-sectional level, and also over time. Loneliness was also found to cross-sectionally predict self-rated health, although this relationship was not present at a longitudinal level. Older adults' self-rated health may be related to their executive functioning and to their loneliness. Self-rated health appeared to improve over time, and the extent of this improvement was also related to executive functioning at baseline. Self-rated health may be a judgement made of one's functioning, especially executive functioning, which changes with age and therefore may be particularly salient in the reflections of older adults.

  19. Quantum arrival-time distributions from intensity functions

    DEFF Research Database (Denmark)

    Wlodarz, Joachim

    2002-01-01

    is similar in nature to other time-dependent arrival-type processes occurring, e.g., in population biology or queue theory. A simple but illustrative example related to the well-known Wigner discussion of the time-energy uncertainty relation is given and the numerical results obtained are compared...

  20. Utilizing Response Time Distributions for Item Selection in CAT

    Science.gov (United States)

    Fan, Zhewen; Wang, Chun; Chang, Hua-Hua; Douglas, Jeffrey

    2012-01-01

    Traditional methods for item selection in computerized adaptive testing only focus on item information without taking into consideration the time required to answer an item. As a result, some examinees may receive a set of items that take a very long time to finish, and information is not accrued as efficiently as possible. The authors propose two…

  1. 7 CFR 1435.504 - Timing of distribution of CCC-owned sugar.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Timing of distribution of CCC-owned sugar. 1435.504... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS SUGAR PROGRAM Processor Sugar Payment-In-Kind (PIK) Program § 1435.504 Timing of distribution of CCC-owned sugar. Distribution of sugar...

  2. Real Time Emulation of Dynamic Tariff for Congestion Management in Distribution Networks

    DEFF Research Database (Denmark)

    Rasmussen, Theis Bo; Wu, Qiuwei; Huang, Shaojun

    2016-01-01

    This paper presents the real time evaluation of the dynamic tariff (DT) method for alleviating congestion in a distribution networks with high penetration of distributed energy resources (DERs). The DT method is implemented in a real time digital testing platform that emulates a real distribution...

  3. The FERMI-Elettra distributed real-time framework

    International Nuclear Information System (INIS)

    Pivetta, L.; Gaio, G.; Passuello, R.; Scalamera, G.

    2012-01-01

    FERMI-Elettra is a Free Electron Laser (FEL) based on a 1.5 GeV linac. The pulsed operation of the accelerator and the necessity to characterize and control each electron bunch requires synchronous acquisition of the beam diagnostics together with the ability to drive actuators in real-time at the linac repetition rate. The Adeos/Xenomai real-time extensions have been adopted in order to add real-time capabilities to the Linux based control system computers running the Tango software. A software communication protocol based on Gigabit Ethernet and known as Network Reflective Memory (NRM) has been developed to implement a shared memory across the whole control system, allowing computers to communicate in real-time. The NRM architecture, the real-time performance and the integration in the control system are described. (authors)

  4. Storm blueprints patterns for distributed real-time computation

    CERN Document Server

    Goetz, P Taylor

    2014-01-01

    A blueprints book with 10 different projects built in 10 different chapters which demonstrate the various use cases of storm for both beginner and intermediate users, grounded in real-world example applications.Although the book focuses primarily on Java development with Storm, the patterns are more broadly applicable and the tips, techniques, and approaches described in the book apply to architects, developers, and operations.Additionally, the book should provoke and inspire applications of distributed computing to other industries and domains. Hadoop enthusiasts will also find this book a go

  5. Comprehensive Cost Minimization in Distribution Networks Using Segmented-time Feeder Reconfiguration and Reactive Power Control of Distributed Generators

    DEFF Research Database (Denmark)

    Chen, Shuheng; Hu, Weihao; Chen, Zhe

    2016-01-01

    In this paper, an efficient methodology is proposed to deal with segmented-time reconfiguration problem of distribution networks coupled with segmented-time reactive power control of distributed generators. The target is to find the optimal dispatching schedule of all controllable switches...... and distributed generators’ reactive powers in order to minimize comprehensive cost. Corresponding constraints, including voltage profile, maximum allowable daily switching operation numbers (MADSON), reactive power limits, and so on, are considered. The strategy of grouping branches is used to simplify...... (FAHPSO) is implemented in VC++ 6.0 program language. A modified version of the typical 70-node distribution network and several real distribution networks are used to test the performance of the proposed method. Numerical results show that the proposed methodology is an efficient method for comprehensive...

  6. Analysis and Synthesis of Distributed Real-Time Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    like automotive electronics, real-time multimedia, avionics, medical equipment, and factory systems. The proposed analysis and synthesis techniques derive optimized implementations that fulfill the imposed design constraints. An important part of the implementation process is the synthesis...

  7. Real-time flight test data distribution and display

    Science.gov (United States)

    Nesel, Michael C.; Hammons, Kevin R.

    1988-01-01

    Enhancements to the real-time processing and display systems of the NASA Western Aeronautical Test Range are described. Display processing has been moved out of the telemetry and radar acquisition processing systems super-minicomputers into user/client interactive graphic workstations. Real-time data is provided to the workstations by way of Ethernet. Future enhancement plans include use of fiber optic cable to replace the Ethernet.

  8. Design and simulation for real-time distributed processing systems

    International Nuclear Information System (INIS)

    Legrand, I.C.; Gellrich, A.; Gensah, U.; Leich, H.; Wegner, P.

    1996-01-01

    The aim of this work is to provide a proper framework for the simulation and the optimization of the event building, the on-line third level trigger, and complete event reconstruction processor farm for the future HERA-B experiment. A discrete event, process oriented, simulation developed in concurrent μC++ is used for modelling the farm nodes running with multi-tasking constraints and different types of switching elements and digital signal processors interconnected for distributing the data through the system. An adequate graphic interface to the simulation part which allows to monitor features on-line and to analyze trace files, provides a powerful development tool for evaluating and designing parallel processing architectures. Control software and data flow protocols for event building and dynamic processor allocation are presented for two architectural models. (author)

  9. Timing and Spatial Distribution of Loess in Xinjiang, NW China.

    Directory of Open Access Journals (Sweden)

    Yun Li

    Full Text Available Central Asia is one of the most significant loess regions on Earth, with an important role in understanding Quaternary climate and environmental change. However, in contrast to the widely investigated loess deposits in the Chinese Loess Plateau, the Central Asian loess-paleosol sequences are still insufficiently known and poorly understood. Through field investigation and review of the previous literature, the authors have investigated the distribution, thickness and age of the Xinjiang loess, and analyzed factors that control these parameters in the Xinjiang in northwest China, Central Asia. The loess sediments cover river terraces, low uplands, the margins of deserts and the slopes of the Tianshan Mountains and Kunlun Mountains and are also present in the Ili Basin. The thickness of the Xinjiang loess deposits varies from several meters to 670 m. The variation trend of the sand fraction (>63 μm grain-size contour can indicate the local major wind directions, so we conclude that the NW and NE winds are the main wind directions in the North and South Xinjiang, and the westerly wind mainly transport dust into the Ili basin. We consider persistent drying, adequate regional wind energy and well-developed river terraces to be the main factors controlling the distribution, thickness and formation age of the Xinjiang loess. The well-outcropped loess sections have mainly developed since the middle Pleistocene in Xinjiang, reflecting the appearance of the persistent drying and the present air circulation system. However, the oldest loess deposits are as old as the beginning of the Pliocene in the Tarim Basin, which suggests that earlier aridification occurred in the Tarim Basin rather than in the Ili Basin and the Junggar Basin.

  10. Survey of off-grid dwellings : January and February 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This report presents statistics from the results of a survey on off-grid dwellings in the Yukon. Two hundred and fifty-eight surveys were completed, and all questions asked in the survey were represented in this document. Dwellings were defined as any buildings in which people slept or ate, including cabins, cottages, lodges and camps, year-round or otherwise. Information was provided on whether or not the dwellings were main residences or recreational properties and the lengths of time in which the dwellings were used. Comments were presented on the difficulties of getting mortgages or other financing for off-grid dwellings. Detailed and specific questions were asked, requiring information about distances from electric poles and intentions to connect to the grid; whether or not the property was a subsistence and/or commercial residence; energy sources currently used; heating systems; light sources; water pumping; power generators; telephones; wind and solar power generators; and, costs involved in purchase and maintenance of energy systems. A series of questions revolved around the use, cost and maintenance of generators. Maintenance and installation costs of photovoltaic systems and wind power generators were presented. Micro-hydro system generators were discussed. Future involvement in energy programs was suggested with specific reference to off-grid energy programs. The survey concluded with comments and questions about off-grid energy in general. tabs.

  11. New distributions of the statistical time delay of electrical breakdown in nitrogen

    International Nuclear Information System (INIS)

    Markovic, V Lj; Gocic, S R; Stamenkovic, S N

    2006-01-01

    Two new distributions of the statistical time delay of electrical breakdown in nitrogen are reported in this paper. The Gaussian and Gauss-exponential distributions of statistical time delay have been obtained on the basis of thousands of time delay measurements on a gas tube with a plane-parallel electrode system. Distributions of the statistical time delay are theoretically founded on binomial distribution for the occurrence of initiating electrons and described by using simple analytical and numerical models. The shapes of distributions depend on the electron yields in the interelectrode space originating from residual states. It is shown that a distribution of the statistical time delay changes from exponential and Gauss-exponential to Gaussian distribution due to the influence of residual ionization

  12. Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks

    Directory of Open Access Journals (Sweden)

    Chaoyang Shi

    2017-12-01

    Full Text Available Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are first estimated from point detector observations. The travel time distributions of links without point detectors are imputed based on their spatial correlations with links that have point detectors. The estimated link travel time distributions are then fused with path travel time distributions obtained from the interval detectors using Dempster-Shafer evidence theory. Based on fused path travel time distribution, an optimization technique is further introduced to update link travel time distributions and their spatial correlations. A case study was performed using real-world data from Hong Kong and showed that the proposed method obtained accurate and robust estimations of link and path travel time distributions in congested road networks.

  13. Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks.

    Science.gov (United States)

    Shi, Chaoyang; Chen, Bi Yu; Lam, William H K; Li, Qingquan

    2017-12-06

    Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are first estimated from point detector observations. The travel time distributions of links without point detectors are imputed based on their spatial correlations with links that have point detectors. The estimated link travel time distributions are then fused with path travel time distributions obtained from the interval detectors using Dempster-Shafer evidence theory. Based on fused path travel time distribution, an optimization technique is further introduced to update link travel time distributions and their spatial correlations. A case study was performed using real-world data from Hong Kong and showed that the proposed method obtained accurate and robust estimations of link and path travel time distributions in congested road networks.

  14. Residence time distribution in twin-screw extruders

    NARCIS (Netherlands)

    Jager, T.

    1992-01-01

    For the twin-screw extruders used in the food industry at short time high temperature processes the knowledge of their reactor properties is incomplete for mass- and heat flow. Therefore each process change such as: scale-up or product development requires a great number of measurements

  15. Poverty index with time-varying consumption and income distributions

    Science.gov (United States)

    Chattopadhyay, Amit K.; Kumar, T. Krishna; Mallick, Sushanta K.

    2017-03-01

    Starting from a stochastic agent-based model to represent market exchange in a developing economy, we study time variations of the probability density function of income with simultaneous variation of the consumption deprivation (CD), where CD represents the shortfall in consumption from the saturation level of an essential commodity, cereal. Together, these two models combine income-expenditure-based market dynamics with time variations in consumption due to income. In this new unified theoretical structure, exchange of trade in assets is only allowed when the income exceeds consumption-deprivation while CD itself is endogenously obtained from a separate kinetic model. Our results reveal that the nature of time variation of the CD function leads to a downward trend in the threshold level of consumption of basic necessities, suggesting a possible dietary transition in terms of lower saturation level of food-grain consumption, possibly through an improvement in the level of living. The new poverty index, defined as CD, is amenable to approximate probabilistic prediction within a short time horizon. A major achievement of this work is the intrinsic independence of the poverty index from an exogenous poverty line, making it more objective for policy formulation as opposed to existing poverty indices in the literature.

  16. A distributed real-time Java system based on CSP

    NARCIS (Netherlands)

    Bakkers, André; Hilderink, G.H.; Broenink, Johannes F.

    1999-01-01

    Real-time embedded systems in general require a reliability that is orders of magnitude higher than what is presently obtainable with state of the art C programs. The reason for the poor reliability of present day software is the unavailability of a formalism to design sequential C programs. The use

  17. Scheduling and Communication Synthesis for Distributed Real-Time Systems

    DEFF Research Database (Denmark)

    Pop, Paul

    2000-01-01

    on aspects of scheduling and communication for embedded real-time systems. Special emphasis has been placed on the impact of the communication infrastructure and protocol on the overall system performance. The scheduling and communication strategies proposed are based on an abstract graph representation...

  18. Distinct Response Time Distributions in Attention Deficit Hyperactivity Disorder Subtypes

    Science.gov (United States)

    Querne, Laurent; Berquin, Patrick

    2009-01-01

    Objective: To address the issue of response time (RT) profiles in hyperactive-impulsive (ADHD-HI), inattentive (ADHD-IA), and combined (ADHD-C) subtypes of ADHD. We hypothesized that children with ADHD-HI should respond more rapidly than children without ADHD and children with ADHD-IA and ADHD-C should respond more slowly than children without…

  19. Representing real time semantics for distributed application integration

    NARCIS (Netherlands)

    Poon, P.M.S.; Dillon, T.S.; Chang, E.; Feng, L.

    Traditional real time system design and development are driven by technological requirements. With the ever growing complexity of requirements and the advances in software design, the alignment of focus has gradually been shifted to the perspective of business and industrial needs. This paper

  20. Critical capacity, travel time delays and travel time distribution of rapid mass transit systems

    Science.gov (United States)

    Legara, Erika Fille; Monterola, Christopher; Lee, Kee Khoon; Hung, Gih Guang

    2014-07-01

    We set up a mechanistic agent-based model of a rapid mass transit system. Using empirical data from Singapore's unidentifiable smart fare card, we validate our model by reconstructing actual travel demand and duration of travel statistics. We subsequently use this model to investigate two phenomena that are known to significantly affect the dynamics within the RTS: (1) overloading in trains and (2) overcrowding in the RTS platform. We demonstrate that by varying the loading capacity of trains, a tipping point emerges at which an exponential increase in the duration of travel time delays is observed. We also probe the impact on the rail system dynamics of three types of passenger growth distribution across stations: (i) Dirac delta, (ii) uniform and (iii) geometric, which is reminiscent of the effect of land use on transport. Under the assumption of a fixed loading capacity, we demonstrate the dependence of a given origin-destination (OD) pair on the flow volume of commuters in station platforms.

  1. The M/G/1 queue with heavy-tailed service time distribution

    NARCIS (Netherlands)

    Boxma, O.J.; Cohen, J.W.

    1998-01-01

    In modern teletraffic applications of queueing theory, service time distributions B(t) with a heavy tail occur, i.e., 1-B(t)~Ct-v for t¿8 with v>1. For such service time distributions, not much explicit information is available concerning the tail probabilities of the corresponding waiting time

  2. Time-dependent polar distribution of outgassing from a spacecraft

    Science.gov (United States)

    Scialdone, J. J.

    1974-01-01

    A technique has been developed to obtain a characterization of the self-generated environment of a spacecraft and its variation with time, angular position, and distance. The density, pressure, outgassing flux, total weight loss, and other important parameters were obtained from data provided by two mass measuring crystal microbalances, mounted back to back, at distance of 1 m from the spacecraft equivalent surface. A major outgassing source existed at an angular position of 300 deg to 340 deg, near the rocket motor, while the weakest source was at the antennas. The strongest source appeared to be caused by a material diffusion process which produced a directional density at 1 m distance of about 1.6 x 10 to the 11th power molecules/cu cm after 1 hr in vacuum and decayed to 1.6 x 10 to the 9th power molecules/cu cm after 200 hr. The total average outgassing flux at the same distance and during the same time span changed from 1.2 x 10 to the minus 7th power to 1.4 x to the minus 10th power g/sq cm/s. These values are three times as large at the spacecraft surface. Total weight loss was 537 g after 10 hr and about 833 g after 200 hr. Self-contamination of the spacecraft was equivalent to that in orbit at about 300-km altitude.

  3. Real Time Updating in Distributed Urban Rainfall Runoff Modelling

    DEFF Research Database (Denmark)

    Borup, Morten; Madsen, Henrik

    that are being updated from system measurements was studied. The results showed that the fact alone that it takes time for rainfall data to travel the distance between gauges and catchments has such a big negative effect on the forecast skill of updated models, that it can justify the choice of even very...... as in a real data case study. The results confirmed that the method is indeed suitable for DUDMs and that it can be used to utilise upstream as well as downstream water level and flow observations to improve model estimates and forecasts. Due to upper and lower sensor limits many sensors in urban drainage...

  4. Radon measurements in hispaniola dwellings

    International Nuclear Information System (INIS)

    Gutierrez, J.; Colgan, P.A.; Cancio, D.

    1996-01-01

    The results of a national radon survey and a number of regional surveys of radon in spanish dwelling are reviewed. The best estimate of the geometric mean of indoor radon concentrations is 41.1. Bq/m -3 and single-family dwellings have been shown to be more at risk than apartments. Results need to be interpreted with some caution due to differences in survey methodologies and measurement procedures. The risks from radon exposure are put in perspective by comparison with other voluntary risks. Finally, although a number of 'high risk' areas have already been identified, it is concluded that implementation of a national programme to reduce radon exposure may await a better definition of the problem extent. (authors). 20 refs., 1 tab

  5. Radiotracer investigation to study residence time distribution in an evaporator system

    Energy Technology Data Exchange (ETDEWEB)

    Pant, H J; Yelgaonkar, V N; Navada, S V [Isotope Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Determination of mean residence time, residence time distribution and evaluation of flow behavior in industrial process systems is of prime importance in order to control the process and to evaluate the performance of the process systems. This paper describes a case study carried out in an evaporator system in a sugar factory near Pune for determination of the mean residence time and residence time distribution using radiotracer technique. The mean residence time (MRT) was determined to be 4 seconds. The mathematical modelling of residence time distribution (RTD) data indicated the flow behaviour of the system to be a well mixed type. (author). 5 refs., 2 figs., 1 tab.

  6. Uncertainties of the 50-year wind from short time series using generalized extreme value distribution and generalized Pareto distribution

    DEFF Research Database (Denmark)

    Larsén, Xiaoli Guo; Mann, Jakob; Rathmann, Ole

    2015-01-01

    This study examines the various sources to the uncertainties in the application of two widely used extreme value distribution functions, the generalized extreme value distribution (GEVD) and the generalized Pareto distribution (GPD). The study is done through the analysis of measurements from...... as a guideline for applying GEVD and GPD to wind time series of limited length. The data analysis shows that, with reasonable choice of relevant parameters, GEVD and GPD give consistent estimates of the return winds. For GEVD, the base period should be chosen in accordance with the occurrence of the extreme wind...

  7. Meaningful spatial and temporal sequences of activities in dwelling

    NARCIS (Netherlands)

    Hematalikeikha, M.A.; Coolen, H.C.C.H.; Pourdeihimi, S.

    2014-01-01

    Human activities based on human needs are affected by affordances and meanings that occur in the dwelling. Activities over time and space have meaningful sequences. The meaningfulness of activities in the cultural framework is conditioned by its special temporality and spatiality. Also, temporal or

  8. An Analysis of Variance Approach for the Estimation of Response Time Distributions in Tests

    Science.gov (United States)

    Attali, Yigal

    2010-01-01

    Generalizability theory and analysis of variance methods are employed, together with the concept of objective time pressure, to estimate response time distributions and the degree of time pressure in timed tests. By estimating response time variance components due to person, item, and their interaction, and fixed effects due to item types and…

  9. Ship-Track Models Based on Poisson-Distributed Port-Departure Times

    National Research Council Canada - National Science Library

    Heitmeyer, Richard

    2006-01-01

    ... of those ships, and their nominal speeds. The probability law assumes that the ship departure times are Poisson-distributed with a time-varying departure rate and that the ship speeds and ship routes are statistically independent...

  10. On Modelling Real-time and Security properties of Distributed Systems

    NARCIS (Netherlands)

    Corin, Ricardo; Etalle, Sandro; Hartel, Pieter H.; Mader, Angelika H.

    2003-01-01

    We discuss a simplified version of the timing attack to illustrate a connection between security and real-time properties of distributed systems. We suggest several avenues for further research on this and similar connections.

  11. Tunneling time distribution by means of Nelson's quantum mechanics and wave-particle duality

    International Nuclear Information System (INIS)

    Hara, Koh'ichiro; Ohba, Ichiro

    2003-01-01

    We calculate a tunneling time distribution by means of Nelson's quantum mechanics and investigate its statistical properties. The relationship between the average and deviation of tunneling time suggests the existence of 'wave-particle duality' in the tunneling phenomena

  12. Estimation of Bimodal Urban Link Travel Time Distribution and Its Applications in Traffic Analysis

    Directory of Open Access Journals (Sweden)

    Yuxiong Ji

    2015-01-01

    Full Text Available Vehicles travelling on urban streets are heavily influenced by traffic signal controls, pedestrian crossings, and conflicting traffic from cross streets, which would result in bimodal travel time distributions, with one mode corresponding to travels without delays and the other travels with delays. A hierarchical Bayesian bimodal travel time model is proposed to capture the interrupted nature of urban traffic flows. The travel time distributions obtained from the proposed model are then considered to analyze traffic operations and estimate travel time distribution in real time. The advantage of the proposed bimodal model is demonstrated using empirical data, and the results are encouraging.

  13. Time-Frequency Distribution of Music based on Sparse Wavelet Packet Representations

    DEFF Research Database (Denmark)

    Endelt, Line Ørtoft

    We introduce a new method for generating time-frequency distributions, which is particularly useful for the analysis of music signals. The method presented here is based on $\\ell1$ sparse representations of music signals in a redundant wavelet packet dictionary. The representations are found using...... the minimization methods basis pursuit and best orthogonal basis. Visualizations of the time-frequency distribution are constructed based on a simplified energy distribution in the wavelet packet decomposition. The time-frequency distributions emphasizes structured musical content, including non-stationary content...

  14. fixedTimeEvents: An R package for the distribution of distances between discrete events in fixed time

    Directory of Open Access Journals (Sweden)

    Kristian Hovde Liland

    2016-01-01

    Full Text Available When a series of Bernoulli trials occur within a fixed time frame or limited space, it is often interesting to assess if the successful outcomes have occurred completely at random, or if they tend to group together. One example, in genetics, is detecting grouping of genes within a genome. Approximations of the distribution of successes are possible, but they become inaccurate for small sample sizes. In this article, we describe the exact distribution of time between random, non-overlapping successes in discrete time of fixed length. A complete description of the probability mass function, the cumulative distribution function, mean, variance and recurrence relation is included. We propose an associated test for the over-representation of short distances and illustrate the methodology through relevant examples. The theory is implemented in an R package including probability mass, cumulative distribution, quantile function, random number generator, simulation functions, and functions for testing.

  15. Just-in-Time Retail Distribution : A Systems Perspective on Cross-Docking

    NARCIS (Netherlands)

    Buijs, Paul; Danhof, Hans W.; Wortmann, J.(Hans) C.

    2016-01-01

    Cross-docking is a just-in-time strategy for distribution logistics. It is aimed at reducing inventory levels and distribution lead times by creating a seamless flow of products from suppliers to customers. Prior supply chain literature has argued that creating such a seamless product flows requires

  16. Individual Differences in Components of Reaction Time Distributions and Their Relations to Working Memory and Intelligence

    Science.gov (United States)

    Schmiedek, Florian; Oberauer, Klaus; Wilhelm, Oliver; Suss, Heinz-Martin; Wittmann, Werner W.

    2007-01-01

    The authors bring together approaches from cognitive and individual differences psychology to model characteristics of reaction time distributions beyond measures of central tendency. Ex-Gaussian distributions and a diffusion model approach are used to describe individuals' reaction time data. The authors identified common latent factors for each…

  17. A search profile for dwellings with elevated radon levels

    DEFF Research Database (Denmark)

    Damkjær, A.; Andersen, C.E.; Majborn, B.

    1996-01-01

    A search profile for dwellings with elevated radon levels has been employed to investigate possibly radon-prone areas in Denmark and to find houses suitable for radon mitigation studies. The profile is defined as dwellings which are single-family houses with slab-on-grade foundation or partly...... basement/slab-on-grade foundation built on either fractured granitic basement rocks, or fractured limestone. Clayey till areas were also included in the profile in order to confirm earlier findings. Three areas representing these surface geologies were selected for indoor radon measurements with CR-39...... track detectors, and a total of 200 houses matching the profile underwent radon measurements during the winter 1994-95. The distribution of the measured radon concentrations were found in most cases to comply with log-normal distributions. Measurements in the living rooms of houses in each of the three...

  18. The distribution of first-passage times and durations in FOREX and future markets

    Science.gov (United States)

    Sazuka, Naoya; Inoue, Jun-ichi; Scalas, Enrico

    2009-07-01

    Possible distributions are discussed for intertrade durations and first-passage processes in financial markets. The view-point of renewal theory is assumed. In order to represent market data with relatively long durations, two types of distributions are used, namely a distribution derived from the Mittag-Leffler survival function and the Weibull distribution. For the Mittag-Leffler type distribution, the average waiting time (residual life time) is strongly dependent on the choice of a cut-off parameter tmax, whereas the results based on the Weibull distribution do not depend on such a cut-off. Therefore, a Weibull distribution is more convenient than a Mittag-Leffler type if one wishes to evaluate relevant statistics such as average waiting time in financial markets with long durations. On the other hand, we find that the Gini index is rather independent of the cut-off parameter. Based on the above considerations, we propose a good candidate for describing the distribution of first-passage time in a market: The Weibull distribution with a power-law tail. This distribution compensates the gap between theoretical and empirical results more efficiently than a simple Weibull distribution. It should be stressed that a Weibull distribution with a power-law tail is more flexible than the Mittag-Leffler distribution, which itself can be approximated by a Weibull distribution and a power-law. Indeed, the key point is that in the former case there is freedom of choice for the exponent of the power-law attached to the Weibull distribution, which can exceed 1 in order to reproduce decays faster than possible with a Mittag-Leffler distribution. We also give a useful formula to determine an optimal crossover point minimizing the difference between the empirical average waiting time and the one predicted from renewal theory. Moreover, we discuss the limitation of our distributions by applying our distribution to the analysis of the BTP future and calculating the average waiting

  19. Channel-Island Connectivity Affects Water Exposure Time Distributions in a Coastal River Delta

    Science.gov (United States)

    Hiatt, Matthew; Castañeda-Moya, Edward; Twilley, Robert; Hodges, Ben R.; Passalacqua, Paola

    2018-03-01

    The exposure time is a water transport time scale defined as the cumulative amount of time a water parcel spends in the domain of interest regardless of the number of excursions from the domain. Transport time scales are often used to characterize the nutrient removal potential of aquatic systems, but exposure time distribution estimates are scarce for deltaic systems. Here we analyze the controls on exposure time distributions using a hydrodynamic model in two domains: the Wax Lake delta in Louisiana, USA, and an idealized channel-island complex. In particular, we study the effects of river discharge, vegetation, network geometry, and tides and use a simple model for the fractional removal of nitrate. In both domains, we find that channel-island hydrological connectivity significantly affects exposure time distributions and nitrate removal. The relative contributions of the island and channel portions of the delta to the overall exposure time distribution are controlled by island vegetation roughness and network geometry. Tides have a limited effect on the system's exposure time distribution but can introduce significant spatial variability in local exposure times. The median exposure time for the WLD model is 10 h under the conditions tested and water transport within the islands contributes to 37-50% of the network-scale exposure time distribution and 52-73% of the modeled nitrate removal, indicating that islands may account for the majority of nitrate removal in river deltas.

  20. Optimal methods for fitting probability distributions to propagule retention time in studies of zoochorous dispersal.

    Science.gov (United States)

    Viana, Duarte S; Santamaría, Luis; Figuerola, Jordi

    2016-02-01

    Propagule retention time is a key factor in determining propagule dispersal distance and the shape of "seed shadows". Propagules dispersed by animal vectors are either ingested and retained in the gut until defecation or attached externally to the body until detachment. Retention time is a continuous variable, but it is commonly measured at discrete time points, according to pre-established sampling time-intervals. Although parametric continuous distributions have been widely fitted to these interval-censored data, the performance of different fitting methods has not been evaluated. To investigate the performance of five different fitting methods, we fitted parametric probability distributions to typical discretized retention-time data with known distribution using as data-points either the lower, mid or upper bounds of sampling intervals, as well as the cumulative distribution of observed values (using either maximum likelihood or non-linear least squares for parameter estimation); then compared the estimated and original distributions to assess the accuracy of each method. We also assessed the robustness of these methods to variations in the sampling procedure (sample size and length of sampling time-intervals). Fittings to the cumulative distribution performed better for all types of parametric distributions (lognormal, gamma and Weibull distributions) and were more robust to variations in sample size and sampling time-intervals. These estimated distributions had negligible deviations of up to 0.045 in cumulative probability of retention times (according to the Kolmogorov-Smirnov statistic) in relation to original distributions from which propagule retention time was simulated, supporting the overall accuracy of this fitting method. In contrast, fitting the sampling-interval bounds resulted in greater deviations that ranged from 0.058 to 0.273 in cumulative probability of retention times, which may introduce considerable biases in parameter estimates. We

  1. Delay-time distribution in the scattering of time-narrow wave packets (II)—quantum graphs

    Science.gov (United States)

    Smilansky, Uzy; Schanz, Holger

    2018-02-01

    We apply the framework developed in the preceding paper in this series (Smilansky 2017 J. Phys. A: Math. Theor. 50 215301) to compute the time-delay distribution in the scattering of ultra short radio frequency pulses on complex networks of transmission lines which are modeled by metric (quantum) graphs. We consider wave packets which are centered at high wave number and comprise many energy levels. In the limit of pulses of very short duration we compute upper and lower bounds to the actual time-delay distribution of the radiation emerging from the network using a simplified problem where time is replaced by the discrete count of vertex-scattering events. The classical limit of the time-delay distribution is also discussed and we show that for finite networks it decays exponentially, with a decay constant which depends on the graph connectivity and the distribution of its edge lengths. We illustrate and apply our theory to a simple model graph where an algebraic decay of the quantum time-delay distribution is established.

  2. Time-dependent angular distribution of sputtered particles from amorphous targets

    International Nuclear Information System (INIS)

    Yamamura, Yasunori

    1990-01-01

    Using the time-evolution computer simulation code DYACAT, the time-dependent behavior of sputtering phenomena has been investigated. The DYACAT program is based on the binary collision approximation, and the cascade development in solids is followed time-evolutionally. The total sputtering yield, the angular distribution and the energy distribution of sputtered atoms are calculated as a function of time for 1 keV Ar→Cu, where the angle of incidence is the inverse surface normal. It is found that the angular distribution of the prompt collisional phase of the sputtering process shows an under-cosine and that the corresponding energy spectrum has a peak near 10 eV. The slow collisional phase of 1 keV Ar→Cu will start after 3x10 -14 s, and its angular distribution shows an over-cosine distribution. (orig.)

  3. Lorentz covariant tempered distributions in two-dimensional space-time

    International Nuclear Information System (INIS)

    Zinov'ev, Yu.M.

    1989-01-01

    The problem of describing Lorentz covariant distributions without any spectral condition has hitherto remained unsolved even for two-dimensional space-time. Attempts to solve this problem have already been made. Zharinov obtained an integral representation for the Laplace transform of Lorentz invariant distributions with support in the product of two-dimensional future light cones. However, this integral representation does not make it possible to obtain a complete description of the corresponding Lorentz invariant distributions. In this paper the author gives a complete description of Lorentz covariant distributions for two-dimensional space-time. No spectral conditions is assumed

  4. Damage Detection Based on Cross-Term Extraction from Bilinear Time-Frequency Distributions

    Directory of Open Access Journals (Sweden)

    Ma Yuchao

    2014-01-01

    Full Text Available Abundant damage information is implicated in the bilinear time-frequency distribution of structural dynamic signals, which could provide effective support for structural damage identification. Signal time-frequency analysis methods are reviewed, and the characters of linear time-frequency distribution and bilinear time-frequency distribution typically represented by the Wigner-Ville distribution are compared. The existence of the cross-term and its application in structural damage detection are demonstrated. A method of extracting the dominant term is proposed, which combines the short-time Fourier spectrum and Wigner-Ville distribution; then two-dimensional time-frequency transformation matrix is constructed and the complete cross-term is extracted finally. The distribution character of which could be applied to the structural damage identification. Through theoretical analysis, model experiment and numerical simulation of the girder structure, the change rate of cross-term amplitude is validated to identify the damage location and degree. The effectiveness of the cross-term of bilinear time-frequency distribution for damage detection is confirmed and the analytical method of damage identification used in structural engineering is available.

  5. Timing System Solution for MedAustron; Real-time Event and Data Distribution Network

    CERN Document Server

    Štefanič, R; Dedič, J; Gutleber, J; Moser, R

    2011-01-01

    MedAustron is an ion beam research and therapy centre under construction in Wiener Neustadt, Austria. The facility features a synchrotron particle accelerator for light ions. The timing system for this class of accelerators has been developed in close collaboration between MedAustron and Cosylab. Mitigating economical and technological risks, we have chosen a proven, widely used Micro Research Finland (MRF) timing equipment and redesigned its FPGA firmware, extending its high-logic services above transport layer, as required by machine specifics. We obtained a generic real-time broadcast network for coordinating actions of a compact, pulse-to-pulse modulation based particle accelerator. High-level services include support for virtual accelerators and a rich selection of event response mechanisms. The system uses a combination of a real-time link for downstream events and a non-real-time link for upstream messaging and non time-critical communication. It comes with National Instruments LabVI...

  6. The waiting time distribution as a graphical approach to epidemiologic measures of drug utilization

    DEFF Research Database (Denmark)

    Hallas, J; Gaist, D; Bjerrum, L

    1997-01-01

    that effectively conveys some essential utilization parameters for a drug. The waiting time distribution for a group of drug users is a charting of their first prescription presentations within a specified time window. For a drug used for chronic treatment, most current users will be captured at the beginning...... of the window. After a few months, the graph will be dominated by new, incident users. As examples, we present waiting time distributions for insulin, ulcer drugs, systemic corticosteroids, antidepressants, and disulfiram. Appropriately analyzed and interpreted, the waiting time distributions can provide...... information about the period prevalence, point prevalence, incidence, duration of use, seasonality, and rate of prescription renewal or relapse for specific drugs. Each of these parameters has a visual correlate. The waiting time distributions may be an informative supplement to conventional drug utilization...

  7. Steady And Unsteady Lumped-Parameter Models For Determination of Groundwater Residence Time Distribution

    International Nuclear Information System (INIS)

    Oezyurt, N.N.

    2002-01-01

    Groundwater's residence time distribution is an important information to identify the transport mechanism in aquifer systems. In the absence or scarcity of geometric, hydraulic and geohydrologic data needed to describe a flow system, lumped parameter models, that handle the flow system as a whole, exist as an alternative to determine the residence time distribution. Lumped parametre models comprise of idealized models of piston and well-mixed flow and their combinations. Aquifer properties such as, dead volume and by-pass flow can also be included in these models. With the aid of these models, conceptual aquifer models can be tested and residence time distribution of groundwater can be determined

  8. Timing system solution for MedAustron; Real-time event and data distribution network

    International Nuclear Information System (INIS)

    Stefanic, R.; Tavcar, R.; Dedic, J.; Gutleber, J.; Moser, R.

    2012-01-01

    MedAustron is an ion beam research and therapy centre under construction in Wiener Neustadt, Austria. The facility features a synchrotron particle accelerator for light ions. The timing system for this class of accelerators has been developed in close collaboration between MedAustron and Cosylab. Mitigating economical and technological risks, we have chosen a proven, widely used Micro Research Finland (MRF) timing equipment and redesigned its FPGA firmware, extending its high-logic services above transport layer, as required by machine specifics. We obtained a generic real-time broadcast network for coordinating actions of a compact, pulse-to-pulse modulation based particle accelerator. High-level services include support for virtual accelerators and a rich selection of event response mechanisms. The system uses a combination of a real-time link for downstream events and a non-real-time link for upstream messaging and non time-critical communication. It comes with National Instruments LabVIEW-based software support, ready to be integrated into PXIe based front-end controllers. This article explains the high level logic services provided by the real-time link, describes the non-real-time interfaces and presents the software configuration mechanisms. (authors)

  9. Lung doses from radon in dwellings and influencing factors

    International Nuclear Information System (INIS)

    Stranden, E.

    1980-01-01

    The radon concentration in Norwegian dwellings and the lung doses received by the Norwegian population are reported. The biological effects of these doses are discussed. The mean value of radon-daughters in Norwegian dwellings was found to be about 7x10 -3 WL (working levels). This corresponds to an annual exposure of about 0.3 WLM (working level months). From studies of the lung cancer statistics of Norway, this exposure may account for about 10% of the annual lung cancer cases in Norway. The variations in the radon concentration inside dwellings are discussed, and the influence of exhalation, ventilation and meteorological parameters upon the respiratory dosage is studied. From the risk estimates performed, the consequences of an increased indoor radon concentration due to reduced ventilation or introduction of building materials with high radium concentrations are discussed. From comparison of the population doses from different sources of radiation, it is evident that a possible future increase in the radon concentration in dwellings is one of the most serious radiation protection problems of our time. (author)

  10. Environmental radon dosimetry in Indian dwellings and workplaces

    Energy Technology Data Exchange (ETDEWEB)

    Kant, K. [K.L.Mehta Dayanand College for Women, Dept. of Physics, Haryana (India); Upadhyay, S.B. [B.S.A. College, Dept. of Physics, Mathura, (India)

    2006-07-01

    Measurements of radon and its progeny in the dwellings and environment of workplaces are important because the radiation dose to human population due to inhalation of radon and its progeny contribute more than 50% of the total dose from natural sources and is the second leading cause of lung cancer after smoking. Recent experimental and epidemiological studies suggest that inhalation of radon progeny, which are the most important source of irradiation of the human respiratory track in workplace and domestic environment could be a cause of lung cancer. The quantification of iidual radon exposure over a long time period is one of the main issues. In the present study, we will report the results of radon monitoring carried out in the environment of workplaces of an oil refinery, LPG bottling plant, thermal power plant and gas power plant, besides the typical and modern Indian dwellings using alpha sensitive L.R.-115 type II solid-state nuclear track detectors in order to quantify the dose to the workers and the inhabitants. For comparison, the radon and its progeny levels were also measured in dwellings far away from the plants. Radon and its progeny levels were found higher in the environment of workplaces and dwellings in the vicinity of the plants. The details of the results obtained will be reported in the full paper. (authors)

  11. Environmental radon dosimetry in Indian dwellings and workplaces

    International Nuclear Information System (INIS)

    Kant, K.; Upadhyay, S.B.

    2006-01-01

    Measurements of radon and its progeny in the dwellings and environment of workplaces are important because the radiation dose to human population due to inhalation of radon and its progeny contribute more than 50% of the total dose from natural sources and is the second leading cause of lung cancer after smoking. Recent experimental and epidemiological studies suggest that inhalation of radon progeny, which are the most important source of irradiation of the human respiratory track in workplace and domestic environment could be a cause of lung cancer. The quantification of individual radon exposure over a long time period is one of the main issues. In the present study, we will report the results of radon monitoring carried out in the environment of workplaces of an oil refinery, LPG bottling plant, thermal power plant and gas power plant, besides the typical and modern Indian dwellings using alpha sensitive L.R.-115 type II solid-state nuclear track detectors in order to quantify the dose to the workers and the inhabitants. For comparison, the radon and its progeny levels were also measured in dwellings far away from the plants. Radon and its progeny levels were found higher in the environment of workplaces and dwellings in the vicinity of the plants. The details of the results obtained will be reported in the full paper. (authors)

  12. 517 DWELLING DENSITY VARIABILITY ACROSS GOVERNMENT ...

    African Journals Online (AJOL)

    Osondu

    confidence level, apartment type had no significant effect on dwelling density in ... words: dwelling density, home spaces, housing units, multifamily apartments ... spaces for work, Obateru (2005) defined .... of Statistics Year Book, 2008; Seeling et al., ... stress. The bedroom and habitable room indicators show similar trend.

  13. Cooking exhaust systems for low energy dwellings

    NARCIS (Netherlands)

    Jacobs, P.; Borsboom, W.A.

    2017-01-01

    Especially in airtight low energy dwellings exhaust systems are of utmost importance as cooking can be a major source of PM2.5 exposure. Dwellings should be designed including facilities enabling extraction of at least 83 dm3/s (300 m3/h) directly to outside. Residents should be able to select an

  14. [Effects of cutting and reseeding on the ground-dwelling arthropod community in Caragana intermedia forest in desert steppe].

    Science.gov (United States)

    Liu, Ren-Tao; Chai, Yong-Qing; Yang, Xin-Guo; Song, Nai-Ping; Wang, Xin-Yun; Wang, Lei

    2013-01-01

    Taking a 25-year-old Caragana intermedia forest in desert steppe as test object, an investigation was conducted on the ground-dwelling arthropod community in cutting and no-cutting stands with and without reseeding, aimed to understand the effects of cutting, reseeding and their interaction on the individual number and group richness of ground-dwelling arthropod in C. intermedia forest. There were significantly lower number and richness of ground-dwelling arthropod in the open spaces than under the shrubs in the no-cutting and no-reseeding stands. Cutting, reseeding and both of them could significantly increase the number and richness of ground-dwelling arthropod in the open spaces, but not under the shrubs, compared with no cutting or reseeding. Consequently, there were no significant differences in the distribution of ground-dwelling arthropod in the open spaces and under the shrubs in the cutting, reseeding, or cutting and reseeding stands. Further, there was a similar buffer effect between cutting and reseeding on the ground-dwelling arthropod. No significant differences were observed in the ground-dwelling arthropod distribution, between cutting stand and reseeding stand, between cutting stand and cutting and reseeding stand, and between reseeding stand and cutting and reseeding stand. It was suggested that cutting, reseeding, or both of them could significantly improve the ground-dwelling arthropod diversity especially in the open spaces, being beneficial for the restoration of degraded grassland ecosystem and the rational management on artificial C. intermedia forest in desert steppe.

  15. On the non-optimality of the FB discipline within the service time distribution class IMRL

    NARCIS (Netherlands)

    S. Aalto; U. Ayesta (Urtzi)

    2005-01-01

    textabstractIt is known that, within the service time distribution class DHR, the FB discipline minimizes the mean delay in the M/G/1 queue among all work-conserving and non-anticipating service disciplines. It is also believed that a similar result is valid within a more general distribution class

  16. Attention, spatial integration, and the tail of response time distributions in Stroop task performance

    NARCIS (Netherlands)

    Roelofs, A.P.A.

    2012-01-01

    A few studies have examined selective attention in Stroop task performance through ex-Gaussian analyses of response time (RT) distributions. It has remained unclear whether the tail of the RT distribution in vocal responding reflects spatial integration of relevant and irrelevant attributes, as

  17. DEALed : A tool suite for distributed real-time systems development

    NARCIS (Netherlands)

    Bolshakov, K.; Karpov, Y.; Sintotski, A.; Malyshkin, V.

    1999-01-01

    DEALed is a tool suite for development of distributed systems using DEAL language. DEAL is being developed at Eindhoven University of Technology as a part of DEDOS project. Area of application of the DEALed is the development of the distributed real- time safety-critical control systems.

  18. Passive Optical Networks for the Distribution of Timed Signals in Particle Physics Experiments

    CERN Document Server

    Papakonstantinou, I; Papadopoulos,S; Troska, J; Vasey, F; Baron, S; Santos, L; Silva, S; Stejskal, P; Sigaud, C; Detraz, S; Moreira, P; Darwazeh, I

    2009-01-01

    A passive optical network for timing distribution applications based on FPGAs has been successfully demonstrated. Deterministic latency was achieved in the critical downstream direction where triggers are distributed while a burst mode receiver was successfully implemented in the upstream direction. Finally, a simple and efficient protocol was introduced for the communication between the OLT and the ONUs in the network that maximizes bandwidth utilization.

  19. On the Linear Relation between the Mean and the Standard Deviation of a Response Time Distribution

    Science.gov (United States)

    Wagenmakers, Eric-Jan; Brown, Scott

    2007-01-01

    Although it is generally accepted that the spread of a response time (RT) distribution increases with the mean, the precise nature of this relation remains relatively unexplored. The authors show that in several descriptive RT distributions, the standard deviation increases linearly with the mean. Results from a wide range of tasks from different…

  20. Additive and Interactive Effects on Response Time Distributions in Visual Word Recognition

    Science.gov (United States)

    Yap, Melvin J.; Balota, David A.

    2007-01-01

    Across 3 different word recognition tasks, distributional analyses were used to examine the joint effects of stimulus quality and word frequency on underlying response time distributions. Consistent with the extant literature, stimulus quality and word frequency produced additive effects in lexical decision, not only in the means but also in the…

  1. Validation Support for Distributed Real-Time Embedded Systems in VDM++

    DEFF Research Database (Denmark)

    S. Fitzgerald, John; Gorm Larsen, Peter; Tjell, Simon

    2007-01-01

    We present a tool-supported approach to the validation of system-level timing properties in formal models of distributed real-time embedded systems. Our aim is to provide system architects with rapid feedback on the timing characteristics of alternative designs in the often volatile early stages ...

  2. Modeling Soak-Time Distribution of Trips for Mobile Source Emissions Forecasting: Techniques and Applications

    Science.gov (United States)

    2000-08-01

    The soak-time of vehicle trip starts is defined as the duration of time in which the vehicle's engine is not operating and that precedes a successful vehicle start. The temporal distribution of the soak-time in an area is an important determinant of ...

  3. Integrated response and transit time distributions of watersheds by combining hydrograph separation and long-term transit time modeling

    Directory of Open Access Journals (Sweden)

    M. C. Roa-García

    2010-08-01

    Full Text Available We present a new modeling approach analyzing and predicting the Transit Time Distribution (TTD and the Response Time Distribution (RTD from hourly to annual time scales as two distinct hydrological processes. The model integrates Isotope Hydrograph Separation (IHS and the Instantaneous Unit Hydrograph (IUH approach as a tool to provide a more realistic description of transit and response time of water in catchments. Individual event simulations and parameterizations were combined with long-term baseflow simulation and parameterizations; this provides a comprehensive picture of the catchment response for a long time span for the hydraulic and isotopic processes. The proposed method was tested in three Andean headwater catchments to compare the effects of land use on hydrological response and solute transport. Results show that the characteristics of events and antecedent conditions have a significant influence on TTD and RTD, but in general the RTD of the grassland dominated catchment is concentrated in the shorter time spans and has a higher cumulative TTD, while the forest dominated catchment has a relatively higher response distribution and lower cumulative TTD. The catchment where wetlands concentrate shows a flashier response, but wetlands also appear to prolong transit time.

  4. Asymptotic distributions of coalescence times and ancestral lineage numbers for populations with temporally varying size.

    Science.gov (United States)

    Chen, Hua; Chen, Kun

    2013-07-01

    The distributions of coalescence times and ancestral lineage numbers play an essential role in coalescent modeling and ancestral inference. Both exact distributions of coalescence times and ancestral lineage numbers are expressed as the sum of alternating series, and the terms in the series become numerically intractable for large samples. More computationally attractive are their asymptotic distributions, which were derived in Griffiths (1984) for populations with constant size. In this article, we derive the asymptotic distributions of coalescence times and ancestral lineage numbers for populations with temporally varying size. For a sample of size n, denote by Tm the mth coalescent time, when m + 1 lineages coalesce into m lineages, and An(t) the number of ancestral lineages at time t back from the current generation. Similar to the results in Griffiths (1984), the number of ancestral lineages, An(t), and the coalescence times, Tm, are asymptotically normal, with the mean and variance of these distributions depending on the population size function, N(t). At the very early stage of the coalescent, when t → 0, the number of coalesced lineages n - An(t) follows a Poisson distribution, and as m → n, $$n\\left(n-1\\right){T}_{m}/2N\\left(0\\right)$$ follows a gamma distribution. We demonstrate the accuracy of the asymptotic approximations by comparing to both exact distributions and coalescent simulations. Several applications of the theoretical results are also shown: deriving statistics related to the properties of gene genealogies, such as the time to the most recent common ancestor (TMRCA) and the total branch length (TBL) of the genealogy, and deriving the allele frequency spectrum for large genealogies. With the advent of genomic-level sequencing data for large samples, the asymptotic distributions are expected to have wide applications in theoretical and methodological development for population genetic inference.

  5. A Real-Time Fault Management Software System for Distributed Environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — DyMA-FM (Dynamic Multivariate Assessment for Fault Management) is a software architecture for real-time fault management. Designed to run in a distributed...

  6. Providing Survivable Real-Time Communication Service for Distributed Mission Critical Systems

    National Research Council Canada - National Science Library

    Zhao, Wei; Bettati, Riccardo; Vaidya, Nitin

    2005-01-01

    This document is the final report for Providing Survivable Real-Time Communication Service for Distributed Mission Critical Systems, a Texas A AND M project funded through the DARPA Fault Tolerant Networks Program...

  7. Distributed finite-time containment control for double-integrator multiagent systems.

    Science.gov (United States)

    Wang, Xiangyu; Li, Shihua; Shi, Peng

    2014-09-01

    In this paper, the distributed finite-time containment control problem for double-integrator multiagent systems with multiple leaders and external disturbances is discussed. In the presence of multiple dynamic leaders, by utilizing the homogeneous control technique, a distributed finite-time observer is developed for the followers to estimate the weighted average of the leaders' velocities at first. Then, based on the estimates and the generalized adding a power integrator approach, distributed finite-time containment control algorithms are designed to guarantee that the states of the followers converge to the dynamic convex hull spanned by those of the leaders in finite time. Moreover, as a special case of multiple dynamic leaders with zero velocities, the proposed containment control algorithms also work for the case of multiple stationary leaders without using the distributed observer. Simulations demonstrate the effectiveness of the proposed control algorithms.

  8. An Environment for Incremental Development of Distributed Extensible Asynchronous Real-time Systems

    Science.gov (United States)

    Ames, Charles K.; Burleigh, Scott; Briggs, Hugh C.; Auernheimer, Brent

    1996-01-01

    Incremental parallel development of distributed real-time systems is difficult. Architectural techniques and software tools developed at the Jet Propulsion Laboratory's (JPL's) Flight System Testbed make feasible the integration of complex systems in various stages of development.

  9. Towards Real-Time Distributed Planning in Multi-Robot Systems

    KAUST Repository

    Abdelkader, Mohamed

    2018-01-01

    of extensive information exchange (communication). The extensive communication between robots can result in decision delays because of which distributed architecture is often impractical for systems with strict real-time constraints, e.g. when decisions have

  10. Integration of real-time mapping technology in disaster relief distribution.

    Science.gov (United States)

    2013-02-01

    Vehicle routing for disaster relief distribution involves many challenges that distinguish this problem from those in commercial settings, given the time sensitive and resource constrained nature of relief activities. While operations research approa...

  11. A Distributed Framework for Real Time Path Planning in Practical Multi-agent Systems

    KAUST Repository

    Abdelkader, Mohamed; Jaleel, Hassan; Shamma, Jeff S.

    2017-01-01

    We present a framework for distributed, energy efficient, and real time implementable algorithms for path planning in multi-agent systems. The proposed framework is presented in the context of a motivating example of capture the flag which

  12. When the mean is not enough: Calculating fixation time distributions in birth-death processes.

    Science.gov (United States)

    Ashcroft, Peter; Traulsen, Arne; Galla, Tobias

    2015-10-01

    Studies of fixation dynamics in Markov processes predominantly focus on the mean time to absorption. This may be inadequate if the distribution is broad and skewed. We compute the distribution of fixation times in one-step birth-death processes with two absorbing states. These are expressed in terms of the spectrum of the process, and we provide different representations as forward-only processes in eigenspace. These allow efficient sampling of fixation time distributions. As an application we study evolutionary game dynamics, where invading mutants can reach fixation or go extinct. We also highlight the median fixation time as a possible analog of mixing times in systems with small mutation rates and no absorbing states, whereas the mean fixation time has no such interpretation.

  13. Relaxation of the vibrational distribution function in N2 time varying discharges

    International Nuclear Information System (INIS)

    Capitelli, M.; Gorse, C.; Ricard, A.

    1981-01-01

    Relaxation of the electron and vibrational distribution functions have been calculated in function of residence time in nitrogen electrical discharges and post-discharges. In the discharge the vibrational temperature get bigger with the residence time for t -2 s. In the post-discharge the vibrational distribution is evolving in such a manner that the high levels are overpopulated as the low vibrational level population is dropping

  14. Space Network Time Distribution and Synchronization Protocol Development for Mars Proximity Link

    Science.gov (United States)

    Woo, Simon S.; Gao, Jay L.; Mills, David

    2010-01-01

    Time distribution and synchronization in deep space network are challenging due to long propagation delays, spacecraft movements, and relativistic effects. Further, the Network Time Protocol (NTP) designed for terrestrial networks may not work properly in space. In this work, we consider the time distribution protocol based on time message exchanges similar to Network Time Protocol (NTP). We present the Proximity-1 Space Link Interleaved Time Synchronization (PITS) algorithm that can work with the CCSDS Proximity-1 Space Data Link Protocol. The PITS algorithm provides faster time synchronization via two-way time transfer over proximity links, improves scalability as the number of spacecraft increase, lowers storage space requirement for collecting time samples, and is robust against packet loss and duplication which underlying protocol mechanisms provide.

  15. Time Evolving Fission Chain Theory and Fast Neutron and Gamma-Ray Counting Distributions

    International Nuclear Information System (INIS)

    Kim, K. S.; Nakae, L. F.; Prasad, M. K.; Snyderman, N. J.; Verbeke, J. M.

    2015-01-01

    Here, we solve a simple theoretical model of time evolving fission chains due to Feynman that generalizes and asymptotically approaches the point model theory. The point model theory has been used to analyze thermal neutron counting data. This extension of the theory underlies fast counting data for both neutrons and gamma rays from metal systems. Fast neutron and gamma-ray counting is now possible using liquid scintillator arrays with nanosecond time resolution. For individual fission chains, the differential equations describing three correlated probability distributions are solved: the time-dependent internal neutron population, accumulation of fissions in time, and accumulation of leaked neutrons in time. Explicit analytic formulas are given for correlated moments of the time evolving chain populations. The equations for random time gate fast neutron and gamma-ray counting distributions, due to randomly initiated chains, are presented. Correlated moment equations are given for both random time gate and triggered time gate counting. There are explicit formulas for all correlated moments are given up to triple order, for all combinations of correlated fast neutrons and gamma rays. The nonlinear differential equations for probabilities for time dependent fission chain populations have a remarkably simple Monte Carlo realization. A Monte Carlo code was developed for this theory and is shown to statistically realize the solutions to the fission chain theory probability distributions. Combined with random initiation of chains and detection of external quanta, the Monte Carlo code generates time tagged data for neutron and gamma-ray counting and from these data the counting distributions.

  16. Distribution of arrival times of muons with energy greater than 10 GeV

    International Nuclear Information System (INIS)

    Badino, G.; Bianco, P.; Dardo, M.; Fulgione, W.; Galeotti, P.; Periale, L.; Saavedra, O.

    1982-01-01

    Recent data on the arrival time distribution of EAS of primary energy >=10 14 eV, and of high energy muons detected at great depth (5000 mwe), seem to indicate an excess of short time intervals. We are using an apparatus, installed at 40 mwe underground, and a surface shower array to investigate the distributions of a) the time intervals between muon groups and b) the arrival times of muons with respect to the front of air showers. Preliminary results of this search are presented

  17. Effect of a data buffer on the recorded distribution of time intervals for random events

    Energy Technology Data Exchange (ETDEWEB)

    Barton, J C [Polytechnic of North London (UK)

    1976-03-15

    The use of a data buffer enables the distribution of the time intervals between events to be studied for times less than the recording system dead-time but the usual negative exponential distribution for random events has to be modified. The theory for this effect is developed for an n-stage buffer followed by an asynchronous recorder. Results are evaluated for the values of n from 1 to 5. In the language of queueing theory the system studied is of type M/D/1/n+1, i.e. with constant service time and a finite number of places.

  18. Part-time wage-gap in Germany: Evidence across the wage distribution

    OpenAIRE

    Tõnurist, Piret; Pavlopoulos, D.

    2013-01-01

    This paper uses insights from labour-market segmentation theory to investigate the wage differences between part-time and full-time workers in Germany at different parts of the wage distribution. This is accomplished with the use of a quintile regression and panel data from the SOEP (1991-2008). To get more insight on the part-time wage-gap, we apply a counterfactual wage decomposition analysis. The results show that, in the lower end of the wage distribution, part-time workers receive lower ...

  19. Angular distribution of scission neutrons studied with time-dependent Schrödinger equation

    Science.gov (United States)

    Wada, Takahiro; Asano, Tomomasa; Carjan, Nicolae

    2018-03-01

    We investigate the angular distribution of scission neutrons taking account of the effects of fission fragments. The time evolution of the wave function of the scission neutron is obtained by integrating the time-dependent Schrodinger equation numerically. The effects of the fission fragments are taken into account by means of the optical potentials. The angular distribution is strongly modified by the presence of the fragments. In the case of asymmetric fission, it is found that the heavy fragment has stronger effects. Dependence on the initial distribution and on the properties of fission fragments is discussed. We also discuss on the treatment of the boundary to avoid artificial reflections

  20. Robust distributed model predictive control of linear systems with structured time-varying uncertainties

    Science.gov (United States)

    Zhang, Langwen; Xie, Wei; Wang, Jingcheng

    2017-11-01

    In this work, synthesis of robust distributed model predictive control (MPC) is presented for a class of linear systems subject to structured time-varying uncertainties. By decomposing a global system into smaller dimensional subsystems, a set of distributed MPC controllers, instead of a centralised controller, are designed. To ensure the robust stability of the closed-loop system with respect to model uncertainties, distributed state feedback laws are obtained by solving a min-max optimisation problem. The design of robust distributed MPC is then transformed into solving a minimisation optimisation problem with linear matrix inequality constraints. An iterative online algorithm with adjustable maximum iteration is proposed to coordinate the distributed controllers to achieve a global performance. The simulation results show the effectiveness of the proposed robust distributed MPC algorithm.

  1. Dwelling on Everyday Car Journeys

    DEFF Research Database (Denmark)

    Tølbøll, Lene; Jensen, Hanne Louise

    different traffic conditions as well as the emotional states related to the drivers’ thoughts about work and family issues, the materiality of the car and the recreational activities inside the car. Analyses are based on a web-based questionnaire, sent to 373 participating drivers in the Big Data research...... project Intelligent Transportation System Platform North Denmark (Lahrmann 2012). In that project data on e.g. position and speed was collected via an On Board Unit from more than 400 cars in 2012-2014 (Tøfting et. al. 2014). The full dataset includes a driven distance of approximately 14 million km...... experiences related to commuting. The findings will be discussed using theoretical inspiration from Sheller (2004), Bull (2003) and Thrift (2004) and we will suggest that the various emotional experiences of the commuters are of great importance for their ability to use of the car as a dwelling place....

  2. A double hit model for the distribution of time to AIDS onset

    Science.gov (United States)

    Chillale, Nagaraja Rao

    2013-09-01

    Incubation time is a key epidemiologic descriptor of an infectious disease. In the case of HIV infection this is a random variable and is probably the longest one. The probability distribution of incubation time is the major determinant of the relation between the incidences of HIV infection and its manifestation to Aids. This is also one of the key factors used for accurate estimation of AIDS incidence in a region. The present article i) briefly reviews the work done, points out uncertainties in estimation of AIDS onset time and stresses the need for its precise estimation, ii) highlights some of the modelling features of onset distribution including immune failure mechanism, and iii) proposes a 'Double Hit' model for the distribution of time to AIDS onset in the cases of (a) independent and (b) dependent time variables of the two markers and examined the applicability of a few standard probability models.

  3. The first-passage time distribution for the diffusion model with variable drift

    DEFF Research Database (Denmark)

    Blurton, Steven Paul; Kesselmeier, Miriam; Gondan, Matthias

    2017-01-01

    across trials. This extra flexibility allows accounting for slow errors that often occur in response time experiments. So far, the predicted response time distributions were obtained by numerical evaluation as analytical solutions were not available. Here, we present an analytical expression...... for the cumulative first-passage time distribution in the diffusion model with normally distributed trial-to-trial variability in the drift. The solution is obtained with predefined precision, and its evaluation turns out to be extremely fast.......The Ratcliff diffusion model is now arguably the most widely applied model for response time data. Its major advantage is its description of both response times and the probabilities for correct as well as incorrect responses. The model assumes a Wiener process with drift between two constant...

  4. Lower bounds on the run time of the univariate marginal distribution algorithm on OneMax

    DEFF Research Database (Denmark)

    Krejca, Martin S.; Witt, Carsten

    2017-01-01

    The Univariate Marginal Distribution Algorithm (UMDA), a popular estimation of distribution algorithm, is studied from a run time perspective. On the classical OneMax benchmark function, a lower bound of Ω(μ√n + n log n), where μ is the population size, on its expected run time is proved...... values maintained by the algorithm, including carefully designed potential functions. These techniques may prove useful in advancing the field of run time analysis for estimation of distribution algorithms in general........ This is the first direct lower bound on the run time of the UMDA. It is stronger than the bounds that follow from general black-box complexity theory and is matched by the run time of many evolutionary algorithms. The results are obtained through advanced analyses of the stochastic change of the frequencies of bit...

  5. Challenges in reducing the computational time of QSTS simulations for distribution system analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Deboever, Jeremiah [Georgia Inst. of Technology, Atlanta, GA (United States); Zhang, Xiaochen [Georgia Inst. of Technology, Atlanta, GA (United States); Reno, Matthew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grijalva, Santiago [Georgia Inst. of Technology, Atlanta, GA (United States); Therrien, Francis [CME International T& D, St. Bruno, QC (Canada)

    2017-06-01

    The rapid increase in penetration of distributed energy resources on the electric power distribution system has created a need for more comprehensive interconnection modelling and impact analysis. Unlike conventional scenario - based studies , quasi - static time - series (QSTS) simulation s can realistically model time - dependent voltage controllers and the diversity of potential impacts that can occur at different times of year . However, to accurately model a distribution system with all its controllable devices, a yearlong simulation at 1 - second resolution is often required , which could take conventional computers a computational time of 10 to 120 hours when an actual unbalanced distribution feeder is modeled . This computational burden is a clear l imitation to the adoption of QSTS simulation s in interconnection studies and for determining optimal control solutions for utility operations . Our ongoing research to improve the speed of QSTS simulation has revealed many unique aspects of distribution system modelling and sequential power flow analysis that make fast QSTS a very difficult problem to solve. In this report , the most relevant challenges in reducing the computational time of QSTS simulations are presented: number of power flows to solve, circuit complexity, time dependence between time steps, multiple valid power flow solutions, controllable element interactions, and extensive accurate simulation analysis.

  6. Prescription duration and treatment episodes in oral glucocorticoid users: application of the parametric waiting time distribution

    DEFF Research Database (Denmark)

    Laugesen, Kristina; Støvring, Henrik; Hallas, Jesper

    2017-01-01

    for oral glucocorticoids and to describe continuous treatment episodes using the parametric waiting time distribution. Methods: We used Danish nationwide registries to identify all prescriptions for oral glucocorticoids during 1996-2014. We applied the parametric waiting time distribution to estimate...... duration of individual prescriptions each year by estimating the 80th, 90th, 95th and 99th percentiles for the interarrival distribution. These corresponded to the time since last prescription during which 80%, 90%, 95% and 99% of users presented a new prescription for redemption. We used the Kaplan...... of the interarrival distribution to apply as prescription duration has an impact on the level of misclassification. Use of the 80th percentile provides a measure of drug exposure that is specific, while the 99th percentile provides a sensitive measure....

  7. Numerical and machine learning simulation of parametric distributions of groundwater residence time in streams and wells

    Science.gov (United States)

    Starn, J. J.; Belitz, K.; Carlson, C.

    2017-12-01

    Groundwater residence-time distributions (RTDs) are critical for assessing susceptibility of water resources to contamination. This novel approach for estimating regional RTDs was to first simulate groundwater flow using existing regional digital data sets in 13 intermediate size watersheds (each an average of 7,000 square kilometers) that are representative of a wide range of glacial systems. RTDs were simulated with particle tracking. We refer to these models as "general models" because they are based on regional, as opposed to site-specific, digital data. Parametric RTDs were created from particle RTDs by fitting 1- and 2-component Weibull, gamma, and inverse Gaussian distributions, thus reducing a large number of particle travel times to 3 to 7 parameters (shape, location, and scale for each component plus a mixing fraction) for each modeled area. The scale parameter of these distributions is related to the mean exponential age; the shape parameter controls departure from the ideal exponential distribution and is partly a function of interaction with bedrock and with drainage density. Given the flexible shape and mathematical similarity of these distributions, any of them are potentially a good fit to particle RTDs. The 1-component gamma distribution provided a good fit to basin-wide particle RTDs. RTDs at monitoring wells and streams often have more complicated shapes than basin-wide RTDs, caused in part by heterogeneity in the model, and generally require 2-component distributions. A machine learning model was trained on the RTD parameters using features derived from regionally available watershed characteristics such as recharge rate, material thickness, and stream density. RTDs appeared to vary systematically across the landscape in relation to watershed features. This relation was used to produce maps of useful metrics with respect to risk-based thresholds, such as the time to first exceedance, time to maximum concentration, time above the threshold

  8. Synchronization of Markovian jumping stochastic complex networks with distributed time delays and probabilistic interval discrete time-varying delays

    International Nuclear Information System (INIS)

    Li Hongjie; Yue Dong

    2010-01-01

    The paper investigates the synchronization stability problem for a class of complex dynamical networks with Markovian jumping parameters and mixed time delays. The complex networks consist of m modes and the networks switch from one mode to another according to a Markovian chain with known transition probability. The mixed time delays are composed of discrete and distributed delays, the discrete time delay is assumed to be random and its probability distribution is known a priori. In terms of the probability distribution of the delays, the new type of system model with probability-distribution-dependent parameter matrices is proposed. Based on the stochastic analysis techniques and the properties of the Kronecker product, delay-dependent synchronization stability criteria in the mean square are derived in the form of linear matrix inequalities which can be readily solved by using the LMI toolbox in MATLAB, the solvability of derived conditions depends on not only the size of the delay, but also the probability of the delay-taking values in some intervals. Finally, a numerical example is given to illustrate the feasibility and effectiveness of the proposed method.

  9. Real time testing of intelligent relays for synchronous distributed generation islanding detection

    Science.gov (United States)

    Zhuang, Davy

    As electric power systems continue to grow to meet ever-increasing energy demand, their security, reliability, and sustainability requirements also become more stringent. The deployment of distributed energy resources (DER), including generation and storage, in conventional passive distribution feeders, gives rise to integration problems involving protection and unintentional islanding. Distributed generators need to be islanded for safety reasons when disconnected or isolated from the main feeder as distributed generator islanding may create hazards to utility and third-party personnel, and possibly damage the distribution system infrastructure, including the distributed generators. This thesis compares several key performance indicators of a newly developed intelligent islanding detection relay, against islanding detection devices currently used by the industry. The intelligent relay employs multivariable analysis and data mining methods to arrive at decision trees that contain both the protection handles and the settings. A test methodology is developed to assess the performance of these intelligent relays on a real time simulation environment using a generic model based on a real-life distribution feeder. The methodology demonstrates the applicability and potential advantages of the intelligent relay, by running a large number of tests, reflecting a multitude of system operating conditions. The testing indicates that the intelligent relay often outperforms frequency, voltage and rate of change of frequency relays currently used for islanding detection, while respecting the islanding detection time constraints imposed by standing distributed generator interconnection guidelines.

  10. Simple Kinematic Pathway Approach (KPA) to Catchment-scale Travel Time and Water Age Distributions

    Science.gov (United States)

    Soltani, S. S.; Cvetkovic, V.; Destouni, G.

    2017-12-01

    The distribution of catchment-scale water travel times is strongly influenced by morphological dispersion and is partitioned between hillslope and larger, regional scales. We explore whether hillslope travel times are predictable using a simple semi-analytical "kinematic pathway approach" (KPA) that accounts for dispersion on two levels of morphological and macro-dispersion. The study gives new insights to shallow (hillslope) and deep (regional) groundwater travel times by comparing numerical simulations of travel time distributions, referred to as "dynamic model", with corresponding KPA computations for three different real catchment case studies in Sweden. KPA uses basic structural and hydrological data to compute transient water travel time (forward mode) and age (backward mode) distributions at the catchment outlet. Longitudinal and morphological dispersion components are reflected in KPA computations by assuming an effective Peclet number and topographically driven pathway length distributions, respectively. Numerical simulations of advective travel times are obtained by means of particle tracking using the fully-integrated flow model MIKE SHE. The comparison of computed cumulative distribution functions of travel times shows significant influence of morphological dispersion and groundwater recharge rate on the compatibility of the "kinematic pathway" and "dynamic" models. Zones of high recharge rate in "dynamic" models are associated with topographically driven groundwater flow paths to adjacent discharge zones, e.g. rivers and lakes, through relatively shallow pathway compartments. These zones exhibit more compatible behavior between "dynamic" and "kinematic pathway" models than the zones of low recharge rate. Interestingly, the travel time distributions of hillslope compartments remain almost unchanged with increasing recharge rates in the "dynamic" models. This robust "dynamic" model behavior suggests that flow path lengths and travel times in shallow

  11. Waiting time distribution revealing the internal spin dynamics in a double quantum dot

    Science.gov (United States)

    Ptaszyński, Krzysztof

    2017-07-01

    Waiting time distribution and the zero-frequency full counting statistics of unidirectional electron transport through a double quantum dot molecule attached to spin-polarized leads are analyzed using the quantum master equation. The waiting time distribution exhibits a nontrivial dependence on the value of the exchange coupling between the dots and the gradient of the applied magnetic field, which reveals the oscillations between the spin states of the molecule. The zero-frequency full counting statistics, on the other hand, is independent of the aforementioned quantities, thus giving no insight into the internal dynamics. The fact that the waiting time distribution and the zero-frequency full counting statistics give a nonequivalent information is associated with two factors. Firstly, it can be explained by the sensitivity to different timescales of the dynamics of the system. Secondly, it is associated with the presence of the correlation between subsequent waiting times, which makes the renewal theory, relating the full counting statistics and the waiting time distribution, no longer applicable. The study highlights the particular usefulness of the waiting time distribution for the analysis of the internal dynamics of mesoscopic systems.

  12. Increased gait unsteadiness in community-dwelling elderly fallers

    Science.gov (United States)

    Hausdorff, J. M.; Edelberg, H. K.; Mitchell, S. L.; Goldberger, A. L.; Wei, J. Y.

    1997-01-01

    OBJECTIVE: To test the hypothesis that quantitative measures of gait unsteadiness are increased in community-dwelling elderly fallers. STUDY DESIGN: Retrospective, case-control study. SETTING: General community. PARTICIPANTS: Thirty-five community-dwelling elderly subjects older than 70 years of age who were capable of ambulating independently for 6 minutes were categorized as fallers (age, 82.2 +/- 4.9 yrs [mean +/- SD]; n = 18) and nonfallers (age, 76.5 +/- 4.0 yrs; n = 17) based on history; 22 young (age, 24.6 +/- 1.9 yrs), healthy subjects also participated as a second reference group. MAIN OUTCOME MEASURES: Stride-to-stride variability (standard deviation and coefficient of variation) of stride time, stance time, swing time, and percent stance time measured during a 6-minute walk. RESULTS: All measures of gait variability were significantly greater in the elderly fallers compared with both the elderly nonfallers and the young subjects (p elderly fallers was similar to that of the nonfallers. There were little or no differences in the variability measures of the elderly nonfallers compared with the young subjects. CONCLUSIONS: Stride-to-stride temporal variations of gait are relatively unchanged in community-dwelling elderly nonfallers, but are significantly increased in elderly fallers. Quantitative measurement of gait unsteadiness may be useful in assessing fall risk in the elderly.

  13. Predictive analytics for truck arrival time estimation : a field study at a European distribution center

    NARCIS (Netherlands)

    van der Spoel, Sjoerd; Amrit, Chintan Amrit; van Hillegersberg, Jos

    2017-01-01

    Distribution centres (DCs) are the hubs connecting transport streams in the supply chain. The synchronisation of coming and going cargo at a DC requires reliable arrival times. To achieve this, a reliable method to predict arrival times is needed. A literature review was performed to find the

  14. Polling Systems with Two-Phase Gated Service: Heavy Traffic Results for the Waiting Time Distribution

    NARCIS (Netherlands)

    R.D. van der Mei (Rob); J.A.C. Resing

    2008-01-01

    htmlabstractWe study an asymmetric cyclic polling system with Poisson arrivals, general service-time and switch-over time distributions, and with so-called two-phase gated service at each queue, an interleaving scheme that aims to enforce some level of "fairness" among the different customer

  15. Part-time wage-gap in Germany: Evidence across the wage distribution

    NARCIS (Netherlands)

    Tõnurist, Piret; Pavlopoulos, D.

    2013-01-01

    This paper uses insights from labour-market segmentation theory to investigate the wage differences between part-time and full-time workers in Germany at different parts of the wage distribution. This is accomplished with the use of a quintile regression and panel data from the SOEP (1991-2008). To

  16. 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.

  17. Wigner time-delay distribution in chaotic cavities and freezing transition.

    Science.gov (United States)

    Texier, Christophe; Majumdar, Satya N

    2013-06-21

    Using the joint distribution for proper time delays of a chaotic cavity derived by Brouwer, Frahm, and Beenakker [Phys. Rev. Lett. 78, 4737 (1997)], we obtain, in the limit of the large number of channels N, the large deviation function for the distribution of the Wigner time delay (the sum of proper times) by a Coulomb gas method. We show that the existence of a power law tail originates from narrow resonance contributions, related to a (second order) freezing transition in the Coulomb gas.

  18. Time series behaviour of the number of Air Asia passengers: A distributional approach

    Science.gov (United States)

    Asrah, Norhaidah Mohd; Djauhari, Maman Abdurachman

    2013-09-01

    The common practice to time series analysis is by fitting a model and then further analysis is conducted on the residuals. However, if we know the distributional behavior of time series, the analyses in model identification, parameter estimation, and model checking are more straightforward. In this paper, we show that the number of Air Asia passengers can be represented as a geometric Brownian motion process. Therefore, instead of using the standard approach in model fitting, we use an appropriate transformation to come up with a stationary, normally distributed and even independent time series. An example in forecasting the number of Air Asia passengers will be given to illustrate the advantages of the method.

  19. Effect of agitation time on nutrient distribution in full-scale CSTR biogas digesters.

    Science.gov (United States)

    Kress, Philipp; Nägele, Hans-Joachim; Oechsner, Hans; Ruile, Stephan

    2018-01-01

    The aim of this work was to study the impact of reduced mixing time in a full-scale CSTR biogas reactor from 10 to 5 and to 2min in half an hour on the distribution of DM, acetic acid and FOS/TAC as a measure to cut electricity consumption. The parameters in the digestate were unevenly distributed with the highest concentration measured at the point of feeding. By reducing mixing time, the FOS/TAC value increases by 16.6%. A reduced mixing time of 2min lead to an accumulation of 15% biogas in the digestate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. LHCb : Clock and timing distribution in the LHCb upgraded detector and readout system

    CERN Multimedia

    Alessio, Federico; Barros Marin, M; Cachemiche, JP; Hachon, F; Jacobsson, Richard; Wyllie, Ken

    2014-01-01

    The LHCb experiment is upgrading part of its detector and the entire readout system towards a full 40 MHz readout system in order to run between five and ten times its initial design luminosity and increase its trigger efficiency. In this paper, the new timing, trigger and control distribution system for such an upgrade is reviewed with particular attention given to the distribution of the clock and timing information across the entire readout system, up to the FE and the on-detector electronics. Current ideas are here presented in terms of reliability, jitter, complexity and implementation.

  1. Clock and timing distribution in the LHCb upgraded detector and readout system

    CERN Document Server

    Alessio, F; Barros Marin, M; Cachemiche, JP; Hachon, F; Jacobsson, R; Wyllie, K

    2015-01-01

    The LHCb experiment is upgrading part of its detector and the entire readout system towards a full 40 MHz readout system in order to run between five and ten times its initial design luminosity and increase its trigger efficiency. In this paper, the new timing, trigger and control distribution system for such an upgrade is reviewed with particular attention given to the distribution of the clock and timing information across the entire readout system, up to the FE and the on-detector electronics. Current ideas are here presented in terms of reliability, jitter, complexity and implementation.

  2. Optimal distribution of integration time for intensity measurements in degree of linear polarization polarimetry.

    Science.gov (United States)

    Li, Xiaobo; Hu, Haofeng; Liu, Tiegen; Huang, Bingjing; Song, Zhanjie

    2016-04-04

    We consider the degree of linear polarization (DOLP) polarimetry system, which performs two intensity measurements at orthogonal polarization states to estimate DOLP. We show that if the total integration time of intensity measurements is fixed, the variance of the DOLP estimator depends on the distribution of integration time for two intensity measurements. Therefore, by optimizing the distribution of integration time, the variance of the DOLP estimator can be decreased. In this paper, we obtain the closed-form solution of the optimal distribution of integration time in an approximate way by employing Delta method and Lagrange multiplier method. According to the theoretical analyses and real-world experiments, it is shown that the variance of the DOLP estimator can be decreased for any value of DOLP. The method proposed in this paper can effectively decrease the measurement variance and thus statistically improve the measurement accuracy of the polarimetry system.

  3. Optimal distribution of integration time for intensity measurements in Stokes polarimetry.

    Science.gov (United States)

    Li, Xiaobo; Liu, Tiegen; Huang, Bingjing; Song, Zhanjie; Hu, Haofeng

    2015-10-19

    We consider the typical Stokes polarimetry system, which performs four intensity measurements to estimate a Stokes vector. We show that if the total integration time of intensity measurements is fixed, the variance of the Stokes vector estimator depends on the distribution of the integration time at four intensity measurements. Therefore, by optimizing the distribution of integration time, the variance of the Stokes vector estimator can be decreased. In this paper, we obtain the closed-form solution of the optimal distribution of integration time by employing Lagrange multiplier method. According to the theoretical analysis and real-world experiment, it is shown that the total variance of the Stokes vector estimator can be significantly decreased about 40% in the case discussed in this paper. The method proposed in this paper can effectively decrease the measurement variance and thus statistically improves the measurement accuracy of the polarimetric system.

  4. The time-energy distribution of atoms in a radiation damage cascade

    International Nuclear Information System (INIS)

    Williams, M.M.R.

    1976-01-01

    The time-energy distribution of atoms in a cascade induced by a primary knock-on is obtained by solving the Boltzmann equation. A more general scattering law is used than has hitherto been possible which is based upon a rational approximation to the Thomas-Fermi model of atomic scattering. The virtue of this scheme is that it remains possible to obtain an exact, closed form solution but allows a more realistic description of the scattering process. Time moments of the distribution are obtained from which the slowing down time and associated variance can be calculated. It is shown that the complete time-energy distribution may be reconstructed from the moments. (author)

  5. Solar-assisted low energy dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Esbensen, T V

    1980-02-01

    The Zero Energy House Group was formed as a subproject of the CCMS Solar Energy Pilot Study in 1974 by seven participating countries experimenting with solar-assisted low-energy dwellings for temperate and northern European climatic conditions. A Zero Energy House is one in which solar energy is used to meet the reduced energy needs of buildings incorporating various thermal energy conservation features. This final report of the Zero Energy House Group includes brief descriptions of 13 major low-energy dwellings in the participating CCMS countries. An overall assessment of the state-of-the-art in solar-assisted low-energy dwellings is also included.

  6. Measurement Techniques for Radon in Mines, Dwellings and the Environment

    International Nuclear Information System (INIS)

    Snihs, J.O.

    1983-06-01

    Definitions and units appropriate for radon and radon daughters are given. The principle methods of detection are ionization chamber, scintillation technique, nuclear track detector, thermoluminescent discs and alpha spectrometry. The activity concentration is determined by grab sampling and subsequent measurement, frequent or continuous grab sampling and measurement and continuous sampling and long time integrated measurement. Sampling and measurement strategies for mines, dwellings and the environment are discussed. (author)

  7. Exact and Heuristic Solutions to Minimize Total Waiting Time in the Blood Products Distribution Problem

    Directory of Open Access Journals (Sweden)

    Amir Salehipour

    2012-01-01

    Full Text Available This paper presents a novel application of operations research to support decision making in blood distribution management. The rapid and dynamic increasing demand, criticality of the product, storage, handling, and distribution requirements, and the different geographical locations of hospitals and medical centers have made blood distribution a complex and important problem. In this study, a real blood distribution problem containing 24 hospitals was tackled by the authors, and an exact approach was presented. The objective of the problem is to distribute blood and its products among hospitals and medical centers such that the total waiting time of those requiring the product is minimized. Following the exact solution, a hybrid heuristic algorithm is proposed. Computational experiments showed the optimal solutions could be obtained for medium size instances, while for larger instances the proposed hybrid heuristic is very competitive.

  8. Measurement of radon concentration in Taiz city dwellings-yemen

    International Nuclear Information System (INIS)

    Ali, Taher M.; Ahmed, Hayel A.; Ismail, Rokhsana M.

    2001-01-01

    Radon gas considered being a high part of natural radiation background. Emitting alpha particles; radon daughters may be deposited into the lungs and cause health hazards. For this reason, estimation of radon levels in dwellings was done in many countries. In our country, Radon group in the Department of physics, University of Aden has been studied radon level in Aden dwelling. The present study is about the radon level in Taiz City - Yemen. Passive diffusion dosimeters containing (SSNTD s ) Cr - 39 detectors were used in the present work. 125 dosimeters were distributed into dwellings of ten regions in Taiz City. Results obtained show that Rn 222 levels vary between 4 Bq/m 3 and 99 Bq/m 3 . The average concentration in Al-Hasseb district is 23 Bq/m 3 and in Algumhuri hospital district is 53 Bq/m 3 . In other regions it varies between the two values. Whereas the general average in the Taiz City is 34 Bq/m 3 . (author)

  9. Real-time measurements and their effects on state estimation of distribution power system

    DEFF Research Database (Denmark)

    Han, Xue; You, Shi; Thordarson, Fannar

    2013-01-01

    between the estimated values (voltage and injected power) and the measurements are applied to evaluate the accuracy of the estimated grid states. Eventually, some suggestions are provided for the distribution grid operators on placing the real-time meters in the distribution grid.......This paper aims at analyzing the potential value of using different real-time metering and measuring instruments applied in the low voltage distribution networks for state-estimation. An algorithm is presented to evaluate different combinations of metering data using a tailored state estimator....... It is followed by a case study based on the proposed algorithm. A real distribution grid feeder with different types of meters installed either in the cabinets or at the customer side is selected for simulation and analysis. Standard load templates are used to initiate the state estimation. The deviations...

  10. Acclimation responses to temperature vary with vertical stratification: implications for vulnerability of soil-dwelling species to extreme temperature events.

    Science.gov (United States)

    van Dooremalen, Coby; Berg, Matty P; Ellers, Jacintha

    2013-03-01

    The occurrence of summer heat waves is predicted to increase in amplitude and frequency in the near future, but the consequences of such extreme events are largely unknown, especially for belowground organisms. Soil organisms usually exhibit strong vertical stratification, resulting in more frequent exposure to extreme temperatures for surface-dwelling species than for soil-dwelling species. Therefore soil-dwelling species are expected to have poor acclimation responses to cope with temperature changes. We used five species of surface-dwelling and four species of soil-dwelling Collembola that habituate different depths in the soil. We tested for differences in tolerance to extreme temperatures after acclimation to warm and cold conditions. We also tested for differences in acclimation of the underlying physiology by looking at changes in membrane lipid composition. Chill coma recovery time, heat knockdown time and fatty acid profiles were determined after 1 week of acclimation to either 5 or 20 °C. Our results showed that surface-dwelling Collembola better maintained increased heat tolerance across acclimation temperatures, but no such response was found for cold tolerance. Concordantly, four of the five surface-dwelling Collembola showed up to fourfold changes in relative abundance of fatty acids after 1 week of acclimation, whereas none of the soil-dwelling species showed a significant adjustment in fatty acid composition. Strong physiological responses to temperature fluctuations may have become redundant in soil-dwelling species due to the relative thermal stability of their subterranean habitat. Based on the results of the four species studied, we expect that unless soil-dwelling species can temporarily retreat to avoid extreme temperatures, the predicted increase in heat waves under climatic change renders these soil-dwelling species more vulnerable to extinction than species with better physiological capabilities. Being able to act under a larger thermal

  11. Real-Time Analysis and Forecasting of Multisite River Flow Using a Distributed Hydrological Model

    Directory of Open Access Journals (Sweden)

    Mingdong Sun

    2014-01-01

    Full Text Available A spatial distributed hydrological forecasting system was developed to promote the analysis of river flow dynamic state in a large basin. The research presented the real-time analysis and forecasting of multisite river flow in the Nakdong River Basin using a distributed hydrological model with radar rainfall forecast data. A real-time calibration algorithm of hydrological distributed model was proposed to investigate the particular relationship between the water storage and basin discharge. Demonstrate the approach of simulating multisite river flow using a distributed hydrological model couple with real-time calibration and forecasting of multisite river flow with radar rainfall forecasts data. The hydrographs and results exhibit that calibrated flow simulations are very approximate to the flow observation at all sites and the accuracy of forecasting flow is gradually decreased with lead times extending from 1 hr to 3 hrs. The flow forecasts are lower than the flow observation which is likely caused by the low estimation of radar rainfall forecasts. The research has well demonstrated that the distributed hydrological model is readily applicable for multisite real-time river flow analysis and forecasting in a large basin.

  12. On the Distribution of Earthquake Interevent Times and the Impact of Spatial Scale

    Science.gov (United States)

    Hristopulos, Dionissios

    2013-04-01

    The distribution of earthquake interevent times is a subject that has attracted much attention in the statistical physics literature [1-3]. A recent paper proposes that the distribution of earthquake interevent times follows from the the interplay of the crustal strength distribution and the loading function (stress versus time) of the Earth's crust locally [4]. It was also shown that the Weibull distribution describes earthquake interevent times provided that the crustal strength also follows the Weibull distribution and that the loading function follows a power-law during the loading cycle. I will discuss the implications of this work and will present supporting evidence based on the analysis of data from seismic catalogs. I will also discuss the theoretical evidence in support of the Weibull distribution based on models of statistical physics [5]. Since other-than-Weibull interevent times distributions are not excluded in [4], I will illustrate the use of the Kolmogorov-Smirnov test in order to determine which probability distributions are not rejected by the data. Finally, we propose a modification of the Weibull distribution if the size of the system under investigation (i.e., the area over which the earthquake activity occurs) is finite with respect to a critical link size. keywords: hypothesis testing, modified Weibull, hazard rate, finite size References [1] Corral, A., 2004. Long-term clustering, scaling, and universality in the temporal occurrence of earthquakes, Phys. Rev. Lett., 9210) art. no. 108501. [2] Saichev, A., Sornette, D. 2007. Theory of earthquake recurrence times, J. Geophys. Res., Ser. B 112, B04313/1-26. [3] Touati, S., Naylor, M., Main, I.G., 2009. Origin and nonuniversality of the earthquake interevent time distribution Phys. Rev. Lett., 102 (16), art. no. 168501. [4] Hristopulos, D.T., 2003. Spartan Gibbs random field models for geostatistical applications, SIAM Jour. Sci. Comput., 24, 2125-2162. [5] I. Eliazar and J. Klafter, 2006

  13. 25 CFR 700.55 - Decent, safe, and sanitary dwelling.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Decent, safe, and sanitary dwelling. 700.55 Section 700... PROCEDURES General Policies and Instructions Definitions § 700.55 Decent, safe, and sanitary dwelling. (a) General. The term decent, safe, and sanitary dwelling means a dwelling which— (1) Meets applicable federal...

  14. Modelling the joint distribution of competing risks survival times using copula functions

    OpenAIRE

    Kaishev, V. K.; Haberman, S.; Dimitrova, D. S.

    2005-01-01

    The problem of modelling the joint distribution of survival times in a competing risks model, using copula functions is considered. In order to evaluate this joint distribution and the related overall survival function, a system of non-linear differential equations is solved, which relates the crude and net survival functions of the modelled competing risks, through the copula. A similar approach to modelling dependent multiple decrements was applied by Carriere (1994) who used a Gaussian cop...

  15. Waiting-time distributions of magnetic discontinuities: Clustering or Poisson process?

    International Nuclear Information System (INIS)

    Greco, A.; Matthaeus, W. H.; Servidio, S.; Dmitruk, P.

    2009-01-01

    Using solar wind data from the Advanced Composition Explorer spacecraft, with the support of Hall magnetohydrodynamic simulations, the waiting-time distributions of magnetic discontinuities have been analyzed. A possible phenomenon of clusterization of these discontinuities is studied in detail. We perform a local Poisson's analysis in order to establish if these intermittent events are randomly distributed or not. Possible implications about the nature of solar wind discontinuities are discussed.

  16. Distributed Optimization Design of Continuous-Time Multiagent Systems With Unknown-Frequency Disturbances.

    Science.gov (United States)

    Wang, Xinghu; Hong, Yiguang; Yi, Peng; Ji, Haibo; Kang, Yu

    2017-05-24

    In this paper, a distributed optimization problem is studied for continuous-time multiagent systems with unknown-frequency disturbances. A distributed gradient-based control is proposed for the agents to achieve the optimal consensus with estimating unknown frequencies and rejecting the bounded disturbance in the semi-global sense. Based on convex optimization analysis and adaptive internal model approach, the exact optimization solution can be obtained for the multiagent system disturbed by exogenous disturbances with uncertain parameters.

  17. Multiagent System-Based Distributed Coordinated Control for Radial DC Microgrid Considering Transmission Time Delays

    DEFF Research Database (Denmark)

    Dou, Chun-Xia; Yue, Dong; Guerrero, Josep M.

    2017-01-01

    This paper focuses on a multi-agent based distributed coordinated control for radial DC microgrid considering trans-mission time delays. Firstly, a two-level multi-agent system is constructed, where local control is formulated based on local states and executed by means of the first-level agent......, and dis-tributed coordinated control law is formulated based on wide-area information and executed by means of the secondary- level agent in order to improve the voltage control performances. Afterwards, the research mainly focuses on designing the local controller and the distributed coordinated...

  18. Application of Choi—Williams Reduced Interference Time Frequency Distribution to Machinery Diagnostics

    Directory of Open Access Journals (Sweden)

    Howard A. Gaberson

    1995-01-01

    Full Text Available This article discusses time frequency analysis of machinery diagnostic vibration signals. The short time Fourier transform, the Wigner, and the Choi–Williams distributions are explained and illustrated with test cases. Examples of Choi—Williams analyses of machinery vibration signals are presented. The analyses detect discontinuities in the signals and their timing, amplitude and frequency modulation, and the presence of different components in a vibration signal.

  19. Statistical distribution of time to crack initiation and initial crack size using service data

    Science.gov (United States)

    Heller, R. A.; Yang, J. N.

    1977-01-01

    Crack growth inspection data gathered during the service life of the C-130 Hercules airplane were used in conjunction with a crack propagation rule to estimate the distribution of crack initiation times and of initial crack sizes. A Bayesian statistical approach was used to calculate the fraction of undetected initiation times as a function of the inspection time and the reliability of the inspection procedure used.

  20. The rates and time-delay distribution of multiply imaged supernovae behind lensing clusters

    Science.gov (United States)

    Li, Xue; Hjorth, Jens; Richard, Johan

    2012-11-01

    Time delays of gravitationally lensed sources can be used to constrain the mass model of a deflector and determine cosmological parameters. We here present an analysis of the time-delay distribution of multiply imaged sources behind 17 strong lensing galaxy clusters with well-calibrated mass models. We find that for time delays less than 1000 days, at z = 3.0, their logarithmic probability distribution functions are well represented by P(log Δt) = 5.3 × 10-4Δttilde beta/M2502tilde beta, with tilde beta = 0.77, where M250 is the projected cluster mass inside 250 kpc (in 1014M⊙), and tilde beta is the power-law slope of the distribution. The resultant probability distribution function enables us to estimate the time-delay distribution in a lensing cluster of known mass. For a cluster with M250 = 2 × 1014M⊙, the fraction of time delays less than 1000 days is approximately 3%. Taking Abell 1689 as an example, its dark halo and brightest galaxies, with central velocity dispersions σ>=500kms-1, mainly produce large time delays, while galaxy-scale mass clumps are responsible for generating smaller time delays. We estimate the probability of observing multiple images of a supernova in the known images of Abell 1689. A two-component model of estimating the supernova rate is applied in this work. For a magnitude threshold of mAB = 26.5, the yearly rate of Type Ia (core-collapse) supernovae with time delays less than 1000 days is 0.004±0.002 (0.029±0.001). If the magnitude threshold is lowered to mAB ~ 27.0, the rate of core-collapse supernovae suitable for time delay observation is 0.044±0.015 per year.

  1. Interevent Time Distribution of Renewal Point Process, Case Study: Extreme Rainfall in South Sulawesi

    Science.gov (United States)

    Sunusi, Nurtiti

    2018-03-01

    The study of time distribution of occurrences of extreme rain phenomena plays a very important role in the analysis and weather forecast in an area. The timing of extreme rainfall is difficult to predict because its occurrence is random. This paper aims to determine the inter event time distribution of extreme rain events and minimum waiting time until the occurrence of next extreme event through a point process approach. The phenomenon of extreme rain events over a given period of time is following a renewal process in which the time for events is a random variable τ. The distribution of random variable τ is assumed to be a Pareto, Log Normal, and Gamma. To estimate model parameters, a moment method is used. Consider Rt as the time of the last extreme rain event at one location is the time difference since the last extreme rainfall event. if there are no extreme rain events up to t 0, there will be an opportunity for extreme rainfall events at (t 0, t 0 + δt 0). Furthermore from the three models reviewed, the minimum waiting time until the next extreme rainfall will be determined. The result shows that Log Nrmal model is better than Pareto and Gamma model for predicting the next extreme rainfall in South Sulawesi while the Pareto model can not be used.

  2. Conceptual framework for model-based analysis of residence time distribution in twin-screw granulation

    DEFF Research Database (Denmark)

    Kumar, Ashish; Vercruysse, Jurgen; Vanhoorne, Valerie

    2015-01-01

    Twin-screw granulation is a promising continuous alternative for traditional batchwise wet granulation processes. The twin-screw granulator (TSG) screws consist of transport and kneading element modules. Therefore, the granulation to a large extent is governed by the residence time distribution...... within each module where different granulation rate processes dominate over others. Currently, experimental data is used to determine the residence time distributions. In this study, a conceptual model based on classical chemical engineering methods is proposed to better understand and simulate...... the residence time distribution in a TSG. The experimental data were compared with the proposed most suitable conceptual model to estimate the parameters of the model and to analyse and predict the effects of changes in number of kneading discs and their stagger angle, screw speed and powder feed rate...

  3. High time resolution characteristics of intermediate ion distributions upstream of the earth's bow shock

    Science.gov (United States)

    Potter, D. W.

    1985-01-01

    High time resolution particle data upstream of the bow shock during time intervals that have been identified as having intermediate ion distributions often show high amplitude oscillations in the ion fluxes of energy 2 and 6 keV. These ion oscillations, observed with the particle instruments of the University of California, Berkeley, on the ISEE 1 and 2 spacecraft, are at the same frequency (about 0.04 Hz) as the magnetic field oscillations. Typically, the 6-keV ion flux increases then the 2-keV flux increases followed by a decrease in the 2-keV flux and then the 6-keV flux decreases. This process repeats many times. Although there is no entirely satisfactory explanation, the presence of these ion flux oscillations suggests that distributions often are misidentified as intermediate ion distributions.

  4. The Transit-Time Distribution from the Northern Hemisphere Midlatitude Surface

    Science.gov (United States)

    Orbe, Clara; Waugh, Darryn W.; Newman, Paul A.; Strahan, Susan; Steenrod, Stephen

    2015-01-01

    The distribution of transit times from the Northern Hemisphere (NH) midlatitude surface is a fundamental property of tropospheric transport. Here we present an analysis of the transit time distribution (TTD) since air last contacted the northern midlatitude surface layer, as simulated by the NASA Global Modeling Initiative Chemistry Transport Model. We find that throughout the troposphere the TTD is characterized by long flat tails that reflect the recirculation of old air from the Southern Hemisphere and results in mean ages that are significantly larger than the modal age. Key aspects of the TTD -- its mode, mean and spectral width -- are interpreted in terms of tropospheric dynamics, including seasonal shifts in the location and strength of tropical convection and variations in quasi-isentropic transport out of the northern midlatitude surface layer. Our results indicate that current diagnostics of tropospheric transport are insufficient for comparing model transport and that the full distribution of transit times is a more appropriate constraint.

  5. Flow time analysis of load management late arrival discrete time queueing system with dual service rate using hypo geometrical distribution

    International Nuclear Information System (INIS)

    Shah, S.A.; Shah, W.; Shaikh, F.K.

    2012-01-01

    Flow time analysis is a powerful concept to analyze the flow time of any arriving customer in any system at any instant. A load management mechanism can be employed very effectively in any queueing system by utilizing a system which provides probability of dual service rate. In this paper, we develop and demonstrate the flow and service processes transition diagram to determine the flow time of a customer in a load management late arrival state dependent finite discrete time queueing system with dual service rate where customers are hypo geometrically distributed. We compute the probability mass function of each starting state and total probability mass function. The obtained analytical results are validated with simulation results for varying values of arrival and service probabilities. (author)

  6. A stochastic model of radiation carcinogenesis: Latent time distributions and their properties

    International Nuclear Information System (INIS)

    Klebanov, L.V.; Yakovlev, A.Yu.; Rachev, S.T.

    1993-01-01

    A stochastic model of radiation carcinogenesis is proposed that has much in common with the ideas suggested by M. Pike as early as 1966. The model allows one to obtain a parametric family of substochastic-type distributions for the time of tumor latency that provides a description of the rate of tumor development and the number of affected individuals. With this model it is possible to interpret data on tumor incidence in terms of promotion and progression processes. The basic model is developed for a prolonged irradiation at a constant dose rate and includes short-term irradiation as a special case. A limiting form of the latent time distribution for short-term irradiation at high doses is obtained. This distribution arises in the extreme value theory within the random minima framework. An estimate for the rate of convergence to a limiting distributions is given. Based on the proposed latent time distributions, long-term predictions of carcinogenic risk do not call for information about irradiation dose. As shown by computer simulation studies and real data analysis, the parametric estimation of carcinogenic risk appears to be robust to the loss of statistical information caused by the right-hand censoring of time-to-tumor observations. It seems likely that this property, although revealed by means of a purely empirical procedure, may be useful in selecting a model for the practical purpose of risk prediction. 44 refs., 3 figs., 1 tab

  7. Study on construction of temporary dwellings and problems caused by living long time on Hanshin-Awaji Great Earthquake; Hanshin / Awaji daishinsai ni okeru okyu kasetsu jutaku no secchi to chokikan shiyo suru baai no kadai ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, K.; Nakamura, Y. [Nagasaki Univ. (Japan)] Shimizu, Y. [Kumagai Gumi Co. Ltd., Tokyo (Japan)

    1998-10-20

    Two years after the above-titled earthquake, an examination was performed on inhabitants in the temporary dwelling houses in Kobe, center of the calamity, and problems caused by a long stay there were clarified together with a grasp of the evolving problems by comparing the result of survey carried out immediately after the disaster. The number of such temporary dwelling houses amounted to 29,128 within Kobe City and 3,168 outside of the city. According to the room arrangement, they were either one f 4 types : 2-rooms with a kitchen, 1 room with a kitchen, dormitory and those specifically for aged persons. There were 59,449 applications at the first offer of 2,702 houses. The priority of their assignments and so on are explained. As for the housing structure, numerous complaints concerned with the room temperature, noise and so forth. As for the living environment, lack of nearby commodity shop, omission of transportation access, ill drainage of the housing sites were pointed out and the matters of demand to the local authorities included the installation of mail post and street lights. As for the health management, insomnia, stiff shoulder, lumbago and other bad physical conditions were revealed. The financial difficulty and the high house rent were obstacles to migrate to other places. The prolonged temporary lives worsened the apprehension of dwellers for the earthquake, typhoon, fire and alike. Some features for the calamity are described in comparison with the result of survey on those who were compelled to live under similar conditions by the eruption of Mr. Fugen. 6 refs., 13 figs., 15 tabs.

  8. Time distributions of recurrences of immunogenic and nonimmunogenic tumors following local irradiation

    International Nuclear Information System (INIS)

    Suit, H.D.; Sedlacek, R.; Fagundes, L.; Goitein, M.; Rothman, K.J.

    1978-01-01

    Three hundred and fourteen mice received single-dose irradiation of the right leg and thigh as treatment of an 8-mm mammary carcinoma isotransplant, and were then observed until death, usually by 1000 days. The time distributions of death due to local recurrence, radiation-induced sarcoma, distant metastasis in the absence of local regrowth, second primary, intercurrent disease, and unknown causes have been evaluated. The times for the transplant tumor inoculum to grow to an 8-mm tumor and the times of death due to local regrowth, distant metastasis, or induced tumor were all approximately log-normally distributed. Of the 128 recurrences, the latest-appearing 3 were at 300, 323, and 436 days; no recurrences were noted during the time period from 436 to 1000 days. These findings have been interpreted to mean that in some cases absolute cure of mice of the tumor in the leg was achieved by radiation alone at the dose levels employed. Radiation-induced sarcomas began to appear after 300 days. The time of appearance of the radiation-induced tumors was inversely related to radiation dose. Similar data for an immunogenic fibrosarcoma show that recurrences appeared earlier and were more closely bunched with respect to time than the recurrences of mammary carcinoma. The time distribution of the development of radiation-induced tumors in non-tumor-bearing animals was also approximately long-normally distributed; the slope of the time distribution curve was the same as that for radiation-induced tumors in mice which had been treated for tumor

  9. Assessing the benefits of residential demand response in a real time distribution energy market

    International Nuclear Information System (INIS)

    Siano, Pierluigi; Sarno, Debora

    2016-01-01

    Highlights: • A new probabilistic methodology, integrating DR in a distribution energy market is proposed. • The method can alleviate distribution network congestions. • This method based on D-LMPs allows cost savings for end-user customers. • Innovative thermal and shiftable loads Real Time control algorithms are also presented. - Abstract: In the field of electricity distribution networks and with the advent of smart grids and microgrids, the use of Distribution Locational Marginal Price (D-LMPs) in a Real Time (RT) distribution market managed by a Distribution System Operator (DSO) is discussed in presence of empowered residential end-users that are able to bid for energy by a demand aggregator while following Demand Response (DR) initiatives. Each customer is provided by a transactive controller, which reads the locational market signals and answers with a bid taking into account the user preferences about some appliances involved in DR activities and controlled by smart plugs-in. In particular, Heating Ventilation and Air Conditioning (HVAC) appliances and shiftable loads are controlled so that their consumption profile can be modified according to the price of energy. In order to assess the effectiveness of the proposed method in terms of energy and cost saving, an innovative probabilistic methodology for evaluating the impact of residential DR choices considering uncertainties related to load demand, user preferences, environmental conditions, house thermal behavior and wholesale market trends has been proposed. The uncertainties related to the stochastic variations of the variables involved are modeled by using the Monte Carlo Simulation (MCS) method. The combination of MCS and RT distribution market simulation based on D-LMPs are used to assess the operation and impact of the DR method over one month. Simulations results on an 84-buses distribution network confirmed that the proposed method allows saving costs for residential end-users and making

  10. Design Optimization of Cyber-Physical Distributed Systems using IEEE Time-sensitive Networks (TSN)

    DEFF Research Database (Denmark)

    Pop, Paul; Lander Raagaard, Michael; Craciunas, Silviu S.

    2016-01-01

    to the optimization of distributed cyber-physical systems using real-time Ethernet for communication. Then, we formulate two novel optimization problems related to the scheduling and routing of TT and AVB traffic in TSN. Thus, we consider that we know the topology of the network as well as the set of TT and AVB flows......In this paper we are interested in safety-critical real-time applications implemented on distributed architectures supporting the Time-SensitiveNetworking (TSN) standard. The ongoing standardization of TSN is an IEEE effort to bring deterministic real-time capabilities into the IEEE 802.1 Ethernet...... standard supporting safety-critical systems and guaranteed Quality-of-Service. TSN will support Time-Triggered (TT) communication based on schedule tables, Audio-Video-Bridging (AVB) flows with bounded end-to-end latency as well as Best-Effort messages. We first present a survey of research related...

  11. Monitoring Distributed Real-Time Systems: A Survey and Future Directions

    Science.gov (United States)

    Goodloe, Alwyn E.; Pike, Lee

    2010-01-01

    Runtime monitors have been proposed as a means to increase the reliability of safety-critical systems. In particular, this report addresses runtime monitors for distributed hard real-time systems. This class of systems has had little attention from the monitoring community. The need for monitors is shown by discussing examples of avionic systems failure. We survey related work in the field of runtime monitoring. Several potential monitoring architectures for distributed real-time systems are presented along with a discussion of how they might be used to monitor properties of interest.

  12. Real-Time Reactive Power Distribution in Microgrids by Dynamic Programing

    DEFF Research Database (Denmark)

    Levron, Yoash; Beck, Yuval; Katzir, Liran

    2017-01-01

    In this paper a new real-time optimization method for reactive power distribution in microgrids is proposed. The method enables location of a globally optimal distribution of reactive power under normal operating conditions. The method exploits the typical compact structure of microgrids to obtain...... combination of reactive powers, by means of dynamic programming. Since every single step involves a one-dimensional problem, the complexity of the solution is only linear with the number of clusters, and as a result, a globally optimal solution may be obtained in real time. The paper includes the results...

  13. Dwelling thermal renovation: which stakes, which solutions?

    International Nuclear Information System (INIS)

    Delduc, Paul; Demeulenaere, Laurence; Verdure, Mathieu; Ayong Le Kama, Alain; Fuk Chun Wing, Dimitri; Kiefer, Noemie; Mauroux, Amelie; Charlier, Dorothee; Hini, Sihame; Pinto Silva, Kleber; Giraudet, Louis Gaetan; Nauleau, Marie-Laure; Daussin-Benichou, Jeanne-Marie; Teissier, Olivier; Finidori, Esther; Grandjean, Alain; Allibe, Benoit; Gadrat, Pierre; Couriol, Aude; Menard, Francois; Rouquette, Celine; Houriez, Guillaume; Francois, Dominique; Aubert, Celine; Canardon, Daniel

    2015-01-01

    This publication proposes three sets of contributions. The first one addresses context and stakes. The contributions propose: a literature review on household behaviour and investments in energy efficiency, a focus on the key role of dwellings in energy transition through a comparative study of the four pathways of the National Debate for Energy Transition, and a discussion about consensus and uncertainties regarding the determining factors of heating temperature in dwellings. The second set addresses public policies and their assessment: improvement of the technical-economical assessment of the benefit of dwelling energetic renovations, discussion of the organisation and results of a survey on dwelling, equipment, and energy needs and uses, an analysis of several measures aimed at reaching objectives of energy efficiency of dwellings, a discussion of renovation works quality, a discussion of the impact of the sustainable development tax credit on thermal renovation, the optimisation of energy renovation in co-properties by third party financing, some foreign examples of policies in favour of dwelling thermal renovation. The third set of contributions addresses the needed technical, organisational and market evolutions: how the building sector can face the challenges of energy transition, the possibilities to propose innovative solutions adapted to existing housing buildings, and a comparative analysis of material and building equipment costs and market structures in Europe. Other texts are proposed in appendix: the origin of the Phebus survey, a description of incentive arrangements, and a map of climate zones in France

  14. Neurobiological Mediators of Squalor-dwelling Behavior.

    Science.gov (United States)

    Kahn, David A

    2017-09-01

    Squalor-dwelling behavior has been characterized as living in conditions so unsanitary that feelings of revulsion are elicited among visitors. This behavior is commonly associated with an insensitivity to distress/disgust and a failure to understand the direness of one's living situation, which leads to social isolation and impairment in quality of life. Etiologically, several associations have been described in the literature, including age-related decline, lower socioeconomic status, and rural dwelling status. Primary neuropsychiatric disorders, such as psychosis, alcoholism, dementia, personality disorders, developmental delays, and learning or physical disabilities are frequently seen in squalor-dwelling individuals. However, none of these disorders seems to be necessary or sufficient to explain the behavior. Neurobiologically, squalor-dwelling behavior has been associated with frontal lobe dysfunction as evidenced by executive dysfunction; however, cognitive impairments also fail to completely explain this behavior. The purpose of this report is to describe a typical case of squalor-dwelling behavior and use it as an example to illustrate the complexity of uncovering the neurobiological basis for this maladaptive personal and public health threat. Neuroimaging findings from our case and a review of the literature point toward decreased activity in the insular cortex and the amygdala as a unifying biological explanation for squalor-dwelling behaviors.

  15. Mobile work, multilocal dwelling and spaces of wellbeing.

    Science.gov (United States)

    Gorman-Murray, Andrew; Bissell, David

    2018-05-01

    Mobile work is increasingly common. For our purposes, mobile work entails long-distance commuting arrangements with periods living away from the primary domestic residence that may be considered 'home'. Mobile work reconfigures the relational fabric of 'home', introducing multilocal mooring points into worker's lives, and thus reshaping the spatial and temporal patterns and meanings of dwelling. Geography and cognate disciplines have begun to investigate the spatialities and temporalities of mobile work and multilocal dwelling, including the complexities of space-time management, but as yet little attention has been given to implications and impacts on the wellbeing of workers and their families - this is despite growing concern for worker and family wellbeing in some mobile work sectors, such as FIFO mining. Wellbeing is also a complex and multivalent concept, taking in objective and subjective dimensions, including health indicators and quality of life. In this context, this paper reviews recent literature on mobile work and multilocal dwelling and geographies of wellbeing to identify productive intersections for conceptual and empirical development. We suggest that provocations about space-times of wellbeing (Fleuret and Prugneau, 2015) and wellbeing as a relational, situated assemblage (Atkinson, 2013) are productive for analysing wellbeing in a context of mobility and multilocality. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Estimation of Saturation Flow Rate and Start-Up Lost Time for Signal Timing Based on Headway Distribution

    Directory of Open Access Journals (Sweden)

    Yi Zhao

    2015-01-01

    Full Text Available This study aimed to calibrate saturation flow rate (SFR and start-up lost time (SLT when developing signal timing. In current commonly used methods, SFR for one given lane is usually calibrated from many subjective adjustment factors and a fixed result. SLT is calculated based on the fixed SFR, which prevents local applications in China. Considering the importance of traffic behavior (headway in determining SFR and SLT, this study started from headway distribution and attempted to specify the relationships between headway and vehicle position directly. A common intersection in Nanjing, China, was selected to implement field study and data from 920 queues was collected. Headway distribution was explored and the 78th percentile of headway at each position was selected to build model. Based on the developed relationships, SFR and SLT were calibrated. The results showed that SFR and SLT were correlated with queue length. Moreover, the results showed that it was difficult to reach saturated state even with a long queue length. This paper provides a new perspective on calibrating important parameters in signal timing, which will be useful for traffic agencies to complete signal timing by making the process simpler.

  17. A distributed agent architecture for real-time knowledge-based systems: Real-time expert systems project, phase 1

    Science.gov (United States)

    Lee, S. Daniel

    1990-01-01

    We propose a distributed agent architecture (DAA) that can support a variety of paradigms based on both traditional real-time computing and artificial intelligence. DAA consists of distributed agents that are classified into two categories: reactive and cognitive. Reactive agents can be implemented directly in Ada to meet hard real-time requirements and be deployed on on-board embedded processors. A traditional real-time computing methodology under consideration is the rate monotonic theory that can guarantee schedulability based on analytical methods. AI techniques under consideration for reactive agents are approximate or anytime reasoning that can be implemented using Bayesian belief networks as in Guardian. Cognitive agents are traditional expert systems that can be implemented in ART-Ada to meet soft real-time requirements. During the initial design of cognitive agents, it is critical to consider the migration path that would allow initial deployment on ground-based workstations with eventual deployment on on-board processors. ART-Ada technology enables this migration while Lisp-based technologies make it difficult if not impossible. In addition to reactive and cognitive agents, a meta-level agent would be needed to coordinate multiple agents and to provide meta-level control.

  18. q-Gaussian distributions of leverage returns, first stopping times, and default risk valuations

    Science.gov (United States)

    Katz, Yuri A.; Tian, Li

    2013-10-01

    We study the probability distributions of daily leverage returns of 520 North American industrial companies that survive de-listing during the financial crisis, 2006-2012. We provide evidence that distributions of unbiased leverage returns of all individual firms belong to the class of q-Gaussian distributions with the Tsallis entropic parameter within the interval 1distributions imply a much higher probability of extreme movements in a company’s leverage ratio than forecasted by the normal distribution (q=1). Motivated by these findings, we develop a q-Gaussian generalization of traditional structural models of default. Derived exact analytical expressions for the probability distribution of a first stopping time and its intensity forecast significantly higher probability of default and much wider credit spreads at short time-horizons. Our findings are broadly consistent with the results of empirical studies in equity markets and are essential for single-name default forecasting as well as valuations of portfolio credit risk and economic capital, which might be underestimated by a classic theory of diversified portfolio optimization.

  19. Time dependent and asymptotic neutron number probability distribution calculation using discrete Fourier transform

    International Nuclear Information System (INIS)

    Humbert, Ph.

    2005-01-01

    In this paper we consider the probability distribution of neutrons in a multiplying assembly. The problem is studied using a space independent one group neutron point reactor model without delayed neutrons. We recall the generating function methodology and analytical results obtained by G.I. Bell when the c 2 approximation is used and we present numerical solutions in the general case, without this approximation. The neutron source induced distribution is calculated using the single initial neutron distribution which satisfies a master (Kolmogorov backward) equation. This equation is solved using the generating function method. The generating function satisfies a differential equation and the probability distribution is derived by inversion of the generating function. Numerical results are obtained using the same methodology where the generating function is the Fourier transform of the probability distribution. Discrete Fourier transforms are used to calculate the discrete time dependent distributions and continuous Fourier transforms are used to calculate the asymptotic continuous probability distributions. Numerical applications are presented to illustrate the method. (author)

  20. Analysis of the space, time and energy distribution of Vrancea earthquakes

    International Nuclear Information System (INIS)

    Radulian, M.; Popa, M.

    1995-01-01

    Statistical analysis of fractal properties of space, time and energy distributions of Vrancea intermediate-depth earthquakes is performed on a homogeneous and complete data set. All events with magnitudes M L >2.5 which occurred from 1974 to 1992 are considered. The 19-year time interval includes the major earthquakes of March 4, 1977, August 26, 1986 and May 30, 1990. The subducted plate, lying between 60 km and 180 km depth, is divided into four active zones with characteristic seismic activities. The correlations between the parameters defining the seismic activities in these zones are studied. The predictive properties of the parameters related to the stress distribution on the fault are analysed. The significant anomalies in time and size distributions of earthquakes are emphasized. The correlations between spatial distribution (fractal dimension), the frequency-magnitude distribution (b slope value) and the high-frequency energy radiated by the source (fall off of the displacement spectra) are studied both at the scale of the whole seismogenic volume and the scale of a specific active zone. The results of this study for the Vrancea earthquakes bring evidence in favour of the seismic source model with hierarchical inhomogeneities (Frankel, 1991) (Author) 8 Figs., 2 Tabs., 5 Refs

  1. Real-time definition of non-randomness in the distribution of genomic events.

    Directory of Open Access Journals (Sweden)

    Ulrich Abel

    Full Text Available Features such as mutations or structural characteristics can be non-randomly or non-uniformly distributed within a genome. So far, computer simulations were required for statistical inferences on the distribution of sequence motifs. Here, we show that these analyses are possible using an analytical, mathematical approach. For the assessment of non-randomness, our calculations only require information including genome size, number of (sampled sequence motifs and distance parameters. We have developed computer programs evaluating our analytical formulas for the real-time determination of expected values and p-values. This approach permits a flexible cluster definition that can be applied to most effectively identify non-random or non-uniform sequence motif distribution. As an example, we show the effectivity and reliability of our mathematical approach in clinical retroviral vector integration site distribution.

  2. Studying electron distributions using the time-resolved free-bound spectra from coronal plasmas

    International Nuclear Information System (INIS)

    Matthews, D.L.; Kauffman, R.L.; Kilkenny, J.D.; Lee, R.W.

    1982-11-01

    Absorption of laser light in a plasma by inverse bremsstrahlung, I.B., can lead to a non-Maxwellian velocity distribution provided the electron-elecron collision frequency is too low to equilibrate the velocity distribution in the coronal plasma region of a laser heated aluminum disk by measuring the radiation recombination continuum. The experiments are performed using lambda/sub L/ = 0.532 μm laser light at intensities of approx. 10 16 W/cm 2 . Such parameters are predicted to produce conditions suitable for a non-thermal electron distribution. The shape of the K-shell recombination radiation has been measured using a time-resolved x-ray spectrograph. The electron distribution can be determined from deconvolution of the recombination continuum shape

  3. Bayesian inference for multivariate point processes observed at sparsely distributed times

    DEFF Research Database (Denmark)

    Rasmussen, Jakob Gulddahl; Møller, Jesper; Aukema, B.H.

    We consider statistical and computational aspects of simulation-based Bayesian inference for a multivariate point process which is only observed at sparsely distributed times. For specicity we consider a particular data set which has earlier been analyzed by a discrete time model involving unknown...... normalizing constants. We discuss the advantages and disadvantages of using continuous time processes compared to discrete time processes in the setting of the present paper as well as other spatial-temporal situations. Keywords: Bark beetle, conditional intensity, forest entomology, Markov chain Monte Carlo...

  4. Multiple-parameter bifurcation analysis in a Kuramoto model with time delay and distributed shear

    Science.gov (United States)

    Niu, Ben; Zhang, Jiaming; Wei, Junjie

    2018-05-01

    In this paper, time delay effect and distributed shear are considered in the Kuramoto model. On the Ott-Antonsen's manifold, through analyzing the associated characteristic equation of the reduced functional differential equation, the stability boundary of the incoherent state is derived in multiple-parameter space. Moreover, very rich dynamical behavior such as stability switches inducing synchronization switches can occur in this equation. With the loss of stability, Hopf bifurcating coherent states arise, and the criticality of Hopf bifurcations is determined by applying the normal form theory and the center manifold theorem. On one hand, theoretical analysis indicates that the width of shear distribution and time delay can both eliminate the synchronization then lead the Kuramoto model to incoherence. On the other, time delay can induce several coexisting coherent states. Finally, some numerical simulations are given to support the obtained results where several bifurcation diagrams are drawn, and the effect of time delay and shear is discussed.

  5. Real-Time Congestion Management in Distribution Networks by Flexible Demand Swap

    DEFF Research Database (Denmark)

    Huang, Shaojun; Wu, Qiuwei

    2017-01-01

    In addition to the day-ahead congestion management in distribution networks, the real-time congestion management is very important because many unforeseen events can occur at the real operation time, e.g. loss of generation of distributed energy resources (DERs) or inaccurate forecast of energy...... pumps (HPs) for real time congestion management. The swap method can maintain the power balance of the system and avoid the imbalance cost of activating the flexibility service. An algorithm for forming swaps through optimal power flow (OPF) and mixed integer linear programming (MILP) is proposed...... consumption or production. Flexibility service from demand will be a good option to solve the real-time congestions if the cost of activating the flexibility service is fully addressed. This paper proposes a new method, namely “swap”, to employ the flexibility service from electric vehicles (EVs) and heat...

  6. Methods of Run-Time Error Detection in Distributed Process Control Software

    DEFF Research Database (Denmark)

    Drejer, N.

    of generic run-time error types, design of methods of observing application software behaviorduring execution and design of methods of evaluating run time constraints. In the definition of error types it is attempted to cover all relevant aspects of the application softwaree behavior. Methods of observation......In this thesis, methods of run-time error detection in application software for distributed process control is designed. The error detection is based upon a monitoring approach in which application software is monitored by system software during the entire execution. The thesis includes definition...... and constraint evaluation is designed for the modt interesting error types. These include: a) semantical errors in data communicated between application tasks; b) errors in the execution of application tasks; and c) errors in the timing of distributed events emitted by the application software. The design...

  7. The current duration design for estimating the time to pregnancy distribution

    DEFF Research Database (Denmark)

    Gasbarra, Dario; Arjas, Elja; Vehtari, Aki

    2015-01-01

    This paper was inspired by the studies of Niels Keiding and co-authors on estimating the waiting time-to-pregnancy (TTP) distribution, and in particular on using the current duration design in that context. In this design, a cross-sectional sample of women is collected from those who are currently...... attempting to become pregnant, and then by recording from each the time she has been attempting. Our aim here is to study the identifiability and the estimation of the waiting time distribution on the basis of current duration data. The main difficulty in this stems from the fact that very short waiting...... times are only rarely selected into the sample of current durations, and this renders their estimation unstable. We introduce here a Bayesian method for this estimation problem, prove its asymptotic consistency, and compare the method to some variants of the non-parametric maximum likelihood estimators...

  8. Gamma processes and peaks-over-threshold distributions for time-dependent reliability

    International Nuclear Information System (INIS)

    Noortwijk, J.M. van; Weide, J.A.M. van der; Kallen, M.J.; Pandey, M.D.

    2007-01-01

    In the evaluation of structural reliability, a failure is defined as the event in which stress exceeds a resistance that is liable to deterioration. This paper presents a method to combine the two stochastic processes of deteriorating resistance and fluctuating load for computing the time-dependent reliability of a structural component. The deterioration process is modelled as a gamma process, which is a stochastic process with independent non-negative increments having a gamma distribution with identical scale parameter. The stochastic process of loads is generated by a Poisson process. The variability of the random loads is modelled by a peaks-over-threshold distribution (such as the generalised Pareto distribution). These stochastic processes of deterioration and load are combined to evaluate the time-dependent reliability

  9. Use of spatially distributed time-integrated sediment sampling networks and distributed fine sediment modelling to inform catchment management.

    Science.gov (United States)

    Perks, M T; Warburton, J; Bracken, L J; Reaney, S M; Emery, S B; Hirst, S

    2017-11-01

    Under the EU Water Framework Directive, suspended sediment is omitted from environmental quality standards and compliance targets. This omission is partly explained by difficulties in assessing the complex dose-response of ecological communities. But equally, it is hindered by a lack of spatially distributed estimates of suspended sediment variability across catchments. In this paper, we demonstrate the inability of traditional, discrete sampling campaigns for assessing exposure to fine sediment. Sampling frequencies based on Environmental Quality Standard protocols, whilst reflecting typical manual sampling constraints, are unable to determine the magnitude of sediment exposure with an acceptable level of precision. Deviations from actual concentrations range between -35 and +20% based on the interquartile range of simulations. As an alternative, we assess the value of low-cost, suspended sediment sampling networks for quantifying suspended sediment transfer (SST). In this study of the 362 km 2 upland Esk catchment we observe that spatial patterns of sediment flux are consistent over the two year monitoring period across a network of 17 monitoring sites. This enables the key contributing sub-catchments of Butter Beck (SST: 1141 t km 2 yr -1 ) and Glaisdale Beck (SST: 841 t km 2 yr -1 ) to be identified. The time-integrated samplers offer a feasible alternative to traditional infrequent and discrete sampling approaches for assessing spatio-temporal changes in contamination. In conjunction with a spatially distributed diffuse pollution model (SCIMAP), time-integrated sediment sampling is an effective means of identifying critical sediment source areas in the catchment, which can better inform sediment management strategies for pollution prevention and control. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Detector dead-time effects and paralyzability in high-speed quantum key distribution

    International Nuclear Information System (INIS)

    Rogers, Daniel J; Bienfang, Joshua C; Nakassis, Anastase; Xu Hai; Clark, Charles W

    2007-01-01

    Recent advances in quantum key distribution (QKD) have given rise to systems that operate at transmission periods significantly shorter than the dead times of their component single-photon detectors. As systems continue to increase in transmission rate, security concerns associated with detector dead times can limit the production rate of sifted bits. We present a model of high-speed QKD in this limit that identifies an optimum transmission rate for a system with given link loss and detector response characteristics

  11. Predicting cycle time distributions for integrated processing workstations : an aggregate modeling approach

    NARCIS (Netherlands)

    Veeger, C.P.L.; Etman, L.F.P.; Lefeber, A.A.J.; Adan, I.J.B.F.; Herk, van J.; Rooda, J.E.

    2011-01-01

    To predict cycle time distributions of integrated processing workstations, detailed simulation models are almost exclusively used; these models require considerable development and maintenance effort. As an alternative, we propose an aggregate model that is a lumped-parameter representation of the

  12. A real-time networked camera system : a scheduled distributed camera system reduces the latency

    NARCIS (Netherlands)

    Karatoy, H.

    2012-01-01

    This report presents the results of a Real-time Networked Camera System, com-missioned by the SAN Group in TU/e. Distributed Systems are motivated by two reasons, the first reason is the physical environment as a requirement and the second reason is to provide a better Quality of Service (QoS). This

  13. Robustness of parameter-less remote real-time pressure control in water distribution systems

    CSIR Research Space (South Africa)

    Page, Philip R

    2017-06-01

    Full Text Available One way of reducing water leakage, pipe bursts and water consumption in a water distribution system (WDS) is to manage the pressure to be as low as possible. This can be done by adjusting a pressure control valve (PCV) in real-time in order to keep...

  14. Real-time distributed economic model predictive control for complete vehicle energy management

    NARCIS (Netherlands)

    Romijn, Constantijn; Donkers, Tijs; Kessels, John; Weiland, Siep

    2017-01-01

    In this paper, a real-time distributed economic model predictive control approach for complete vehicle energy management (CVEM) is presented using a receding control horizon in combination with a dual decomposition. The dual decomposition allows the CVEM optimization problem to be solved by solving

  15. Large-time behavior of solutions to a reaction-diffusion system with distributed microstructure

    NARCIS (Netherlands)

    Muntean, A.

    2009-01-01

    Abstract We study the large-time behavior of a class of reaction-diffusion systems with constant distributed microstructure arising when modeling diffusion and reaction in structured porous media. The main result of this Note is the following: As t ¿ 8 the macroscopic concentration vanishes, while

  16. Preservation of correctness during system reconfiguration in Data Distribution Service for Real-Time Systems (DDS)

    NARCIS (Netherlands)

    Zieba, Bogumil; van Sinderen, Marten J.

    This paper addresses dynamic reconfiguration of distributed systems that use a publish/subscribe (pub/sub) middleware. The objective of dynamic reconfiguration is to evolve incrementally from one system configuration to another at run-time in order to e.g., ensure the reliability of the system. The

  17. Time evolution of the drop size distribution for liquid-liquid dispersion in an agitated tank

    Czech Academy of Sciences Publication Activity Database

    Šulc, R.; Kysela, Bohuš; Ditl, P.

    2018-01-01

    Roč. 72, č. 3 (2018), s. 543-553 ISSN 0366-6352 R&D Projects: GA ČR GA16-20175S Institutional support: RVO:67985874 Keywords : liquid–liquid dispersion * drop breakup * drop size distribution * time evolution Subject RIV: BK - Fluid Dynamics Impact factor: 1.258, year: 2016

  18. The Space-, Time-, and Energy-distribution of Neutrons from a Pulsed Plane Source

    Energy Technology Data Exchange (ETDEWEB)

    Claesson, Arne

    1962-05-15

    The space-, time- and energy-distribution of neutrons from a pulsed, plane, high energy source in an infinite medium is determined in a diffusion approximation. For simplicity the moderator is first assumed to be hydrogen gas but it is also shown that the method can be used for a moderator of arbitrary mass.

  19. A combined rheology and time domain NMR approach for determining water distributions in protein blends

    NARCIS (Netherlands)

    Dekkers, Birgit L.; Kort, de Daan W.; Grabowska, Katarzyna J.; Tian, Bei; As, Van Henk; Goot, van der Atze Jan

    2016-01-01

    We present a combined time domain NMR and rheology approach to quantify the water distribution in a phase separated protein blend. The approach forms the basis for a new tool to assess the microstructural properties of phase separated biopolymer blends, making it highly relevant for many food and

  20. Synaptic Dynamics and Neuronal Network Connectivity are reflected in the Distribution of Times in Up states

    Directory of Open Access Journals (Sweden)

    Khanh eDao Duc

    2015-07-01

    Full Text Available The dynamics of neuronal networks connected by synaptic dynamics can sustain long periods of depolarization that can last for hundreds of milliseconds such as Up states recorded during sleep or anesthesia. Yet the underlying mechanism driving these periods remain unclear. We show here within a mean-field model that the residence times of the neuronal membrane potential in cortical Up states does not follow a Poissonian law, but presents several peaks. Furthermore, the present modeling approach allows extracting some information about the neuronal network connectivity from the time distribution histogram. Based on a synaptic-depression model, we find that these peaks, that can be observed in histograms of patch-clamp recordings are not artifacts of electrophysiological measurements, but rather are an inherent property of the network dynamics. Analysis of the equations reveals a stable focus located close to the unstable limit cycle, delimiting a region that defines the Up state. The model further shows that the peaks observed in the Up state time distribution are due to winding around the focus before escaping from the basin of attraction. Finally, we use in vivo recordings of intracellular membrane potential and we recover from the peak distribution, some information about the network connectivity. We conclude that it is possible to recover the network connectivity from the distribution of times that the neuronal membrane voltage spends in Up states.

  1. Residence Time Distribution of Solid Particles in High-Aspect Ratio Multiple-Impeller Stirred Vessel

    Czech Academy of Sciences Publication Activity Database

    Scargiali, F.; Grisafi, F.; Čermáková, Jiřina; Machoň, V.; Brucato, A.

    2004-01-01

    Roč. 59, č. 17 (2004), s. 3601-3618 ISSN 0009-2509 Institutional research plan: CEZ:AV0Z4072921 Keywords : retention time distribution * twin systems approach * particle tracing Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.655, year: 2004

  2. Design optimization of TTEthernet-based distributed real-time systems

    DEFF Research Database (Denmark)

    Tamas-Selicean, Domitian; Pop, Paul; Steiner, Wilfried

    2015-01-01

    Many safety-critical real-time applications are implemented using distributed architectures, composed of heterogeneous processing elements interconnected in a network. Our focus in this paper is on the TTEthernet protocol, a deterministic, synchronized and congestion-free network protocol based o...

  3. Flexibility Driven Scheduling and Mapping for Distributed Real-Time Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2002-01-01

    In this paper we present an approach to mapping and scheduling of distributed hard real-time systems, aiming at improving the flexibility of the design process. We consider an incremental design process that starts from an already existing system running a set of applications, with preemptive...

  4. Dynamic Scheduling of Object Invocations in Distributed Object Oriented Real-Time Systems

    DEFF Research Database (Denmark)

    Jørgensen, Bo Nørregaard; Joosen, Wouter

    1998-01-01

    This paper describes some of the issues that we investigate in order to develop distributed object computing middleware for application domains where timely cooperation and coordination between objects are crucial for guaranteeing correct system behavior. In particular, issues on admission contro...

  5. What Are the Shapes of Response Time Distributions in Visual Search?

    Science.gov (United States)

    Palmer, Evan M.; Horowitz, Todd S.; Torralba, Antonio; Wolfe, Jeremy M.

    2011-01-01

    Many visual search experiments measure response time (RT) as their primary dependent variable. Analyses typically focus on mean (or median) RT. However, given enough data, the RT distribution can be a rich source of information. For this paper, we collected about 500 trials per cell per observer for both target-present and target-absent displays…

  6. The last picture show? Timing and order of movie distribution channels

    NARCIS (Netherlands)

    Hennig-Thurau, Thorsten; Henning, Victor; Sattler, Henrik; Eggers, Felix; Houston, Mark B.

    2007-01-01

    Movies and other media goods are traditionally distributed across distinct sequential channels (e.g., theaters, home video, video on demand). The optimality of the currently employed timing and order of channel openings has become a matter of contentious debate among both industry experts and

  7. WAITING TIME DISTRIBUTION OF SOLAR ENERGETIC PARTICLE EVENTS MODELED WITH A NON-STATIONARY POISSON PROCESS

    International Nuclear Information System (INIS)

    Li, C.; Su, W.; Fang, C.; Zhong, S. J.; Wang, L.

    2014-01-01

    We present a study of the waiting time distributions (WTDs) of solar energetic particle (SEP) events observed with the spacecraft WIND and GOES. The WTDs of both solar electron events (SEEs) and solar proton events (SPEs) display a power-law tail of ∼Δt –γ . The SEEs display a broken power-law WTD. The power-law index is γ 1 = 0.99 for the short waiting times (<70 hr) and γ 2 = 1.92 for large waiting times (>100 hr). The break of the WTD of SEEs is probably due to the modulation of the corotating interaction regions. The power-law index, γ ∼ 1.82, is derived for the WTD of the SPEs which is consistent with the WTD of type II radio bursts, indicating a close relationship between the shock wave and the production of energetic protons. The WTDs of SEP events can be modeled with a non-stationary Poisson process, which was proposed to understand the waiting time statistics of solar flares. We generalize the method and find that, if the SEP event rate λ = 1/Δt varies as the time distribution of event rate f(λ) = Aλ –α exp (– βλ), the time-dependent Poisson distribution can produce a power-law tail WTD of ∼Δt α –3 , where 0 ≤ α < 2

  8. DETERMINATION OF THE RESIDUAL OPERATING TIME OF UNRESTORABLE ELEMENT OF THE ELECTRIC POWER OBJECT AT THE WAYBALL DISTRIBUTION

    International Nuclear Information System (INIS)

    Namgaladze, D.; Gurgenidze, D.

    2007-01-01

    In practice, it is often essential to determinethe residual operating time for an unrestorable element of the electric power object which has operated without failure for a certain time. The density of probability distribution of operating time can be determined from the initial probability distribution of operating time. In this work, the relations for determination of the function of residual operating time of the unrestorable element at the exponential and Wayball distributions are analytically derived. (author)

  9. Dwell fatigue in two Ti alloys: An integrated crystal plasticity and discrete dislocation study

    Science.gov (United States)

    Zheng, Zebang; Balint, Daniel S.; Dunne, Fionn P. E.

    2016-11-01

    It is a well known and important problem in the aircraft engine industry that alloy Ti-6242 shows a significant reduction in fatigue life, termed dwell debit, if a stress dwell is included in the fatigue cycle, whereas Ti-6246 does not; the mechanistic explanation for the differing dwell debit of these alloys has remained elusive for decades. In this work, crystal plasticity modelling has been utilised to extract the thermal activation energies for pinned dislocation escape for both Ti alloys based on independent experimental data. This then allows the markedly different cold creep responses of the two alloys to be captured accurately and demonstrates why the observed near-identical rate sensitivity under non-dwell loading is entirely consistent with the dwell behaviour. The activation energies determined are then utilised within a recently developed thermally-activated discrete dislocation plasticity model to predict the strain rate sensitivities of the two alloys associated with nano-indentation into basal and prism planes. It is shown that Ti-6242 experiences a strong crystallographic orientation-dependent rate sensitivity while Ti-6246 does not which is shown to agree with recently published independent measurements; the dependence of rate sensitivity on indentation slip plane is also well captured. The thermally-activated discrete dislocation plasticity model shows that the incorporation of a stress dwell in fatigue loading leads to remarkable stress redistribution from soft to hard grains in the classical cold dwell fatigue rogue grain combination in alloy Ti-6242, but that no such load shedding occurs in alloy Ti-6246. The key property controlling the behaviour is the time constant of the thermal activation process relative to that of the loading. This work provides the first mechanistic basis to explain why alloy Ti-6242 shows a dwell debit but Ti-6246 does not.

  10. Quasiparticle energy distribution and relaxation times in a tunnel-injected superconductor

    International Nuclear Information System (INIS)

    Kirtley, J.R.; Kent, D.S.; Langenberg, D.N.; Kaplan, S.B.; Chang, J.; Yang, C.

    1980-01-01

    Experiments are reported in which a nonequilibrium quasiparticle distribution was created in a dirty Al film by tunnel injection and probed using a second tunnel junction. The distribution was found to have the form of a quasithermal distribution characterized by an effective temperature greater than the ambient bath temperature and dependent on injection level, plus small sharp structures which originate in structures in the injected quasiparticle distribution due to gap-edge peaks in the quasiparticle density of states. A systematic theoretical analysis of these structures correctly predicts their shapes and relative amplitudes. The amplitudes show directly the presence of branch imbalance in the nonequilibrium quasiparticle distribution. Using the theoretical model, inelastic quasiparticle relaxation and elastic branch mixing times, as functions of energy and temperature, are extracted from the experimental data without need for phonon-trapping corrections. The qualitative and quantitative behavior of these times is in reasonable accord with theoretical expectations and the results of other experiments. Experiments of the type reported here are shown to provide a kind of spectroscopy of tunnel-injection and quasiparticle-relaxation processes in superconductors

  11. Implementation of a Real-Time Microgrid Simulation Platform Based on Centralized and Distributed Management

    Directory of Open Access Journals (Sweden)

    Omid Abrishambaf

    2017-06-01

    Full Text Available Demand response and distributed generation are key components of power systems. Several challenges are raised at both technical and business model levels for integration of those resources in smart grids and microgrids. The implementation of a distribution network as a test bed can be difficult and not cost-effective; using computational modeling is not sufficient for producing realistic results. Real-time simulation allows us to validate the business model’s impact at the technical level. This paper comprises a platform supporting the real-time simulation of a microgrid connected to a larger distribution network. The implemented platform allows us to use both centralized and distributed energy resource management. Using an optimization model for the energy resource operation, a virtual power player manages all the available resources. Then, the simulation platform allows us to technically validate the actual implementation of the requested demand reduction in the scope of demand response programs. The case study has 33 buses, 220 consumers, and 68 distributed generators. It demonstrates the impact of demand response events, also performing resource management in the presence of an energy shortage.

  12. Saddlepoint approximation to the distribution of the total distance of the continuous time random walk

    Science.gov (United States)

    Gatto, Riccardo

    2017-12-01

    This article considers the random walk over Rp, with p ≥ 2, where a given particle starts at the origin and moves stepwise with uniformly distributed step directions and step lengths following a common distribution. Step directions and step lengths are independent. The case where the number of steps of the particle is fixed and the more general case where it follows an independent continuous time inhomogeneous counting process are considered. Saddlepoint approximations to the distribution of the distance from the position of the particle to the origin are provided. Despite the p-dimensional nature of the random walk, the computations of the saddlepoint approximations are one-dimensional and thus simple. Explicit formulae are derived with dimension p = 3: for uniformly and exponentially distributed step lengths, for fixed and for Poisson distributed number of steps. In these situations, the high accuracy of the saddlepoint approximations is illustrated by numerical comparisons with Monte Carlo simulation. Contribution to the "Topical Issue: Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

  13. Estimating interevent time distributions from finite observation periods in communication networks

    Science.gov (United States)

    Kivelä, Mikko; Porter, Mason A.

    2015-11-01

    A diverse variety of processes—including recurrent disease episodes, neuron firing, and communication patterns among humans—can be described using interevent time (IET) distributions. Many such processes are ongoing, although event sequences are only available during a finite observation window. Because the observation time window is more likely to begin or end during long IETs than during short ones, the analysis of such data is susceptible to a bias induced by the finite observation period. In this paper, we illustrate how this length bias is born and how it can be corrected without assuming any particular shape for the IET distribution. To do this, we model event sequences using stationary renewal processes, and we formulate simple heuristics for determining the severity of the bias. To illustrate our results, we focus on the example of empirical communication networks, which are temporal networks that are constructed from communication events. The IET distributions of such systems guide efforts to build models of human behavior, and the variance of IETs is very important for estimating the spreading rate of information in networks of temporal interactions. We analyze several well-known data sets from the literature, and we find that the resulting bias can lead to systematic underestimates of the variance in the IET distributions and that correcting for the bias can lead to qualitatively different results for the tails of the IET distributions.

  14. A comparative study of indoor radon concentrations between dwellings and schools

    International Nuclear Information System (INIS)

    Kapdan, E.; Altinsoy, N.

    2012-01-01

    The aim of this study is to determine the relationship of radon concentrations between dwellings and the schools located in the same regions and to obtain related indoor average radon concentration dwelling–school correction factor for similar locations. The research has been carried out by determining indoor radon concentrations at schools and dwellings located at the same districts in the selected two separate research fields called The Former Adapazari region and The New Adapazari region in the city of Adapazari using a total of 81 Cr-39 passive radon detectors for 75 days. The average radon concentrations have been determined for the dwellings and the schools in 15 districts of the Former Adapazari region as 59.9 Bq m −3 and 57.1 Bq m −3 , respectively. The results in 4 districts of the New Adapazari region were 63.5 Bq m −3 for the dwellings and 61.0 Bq m −3 for the schools. Moreover, the annual effective doses were calculated as 1.33 mSv/y and 1.41 mSv/y for the dwellings of Former Adapazari and New Adapazari, respectively. It was seen that the doses received in the dwellings are about four times the doses received in the schools. The indoor radon concentration dwelling–school correction factor was found to be 1.04±0.01 for the research area.

  15. A novel time dependent gamma evaluation function for dynamic 2D and 3D dose distributions

    International Nuclear Information System (INIS)

    Podesta, Mark; Persoon, Lucas CGG; Verhaegen, Frank

    2014-01-01

    Modern external beam radiotherapy requires detailed verification and quality assurance so that confidence can be placed on both the delivery of a single treatment fraction and on the consistency of delivery throughout the treatment course. To verify dose distributions, a comparison between prediction and measurement must be made. Comparisons between two dose distributions are commonly performed using a Gamma evaluation which is a calculation of two quantities on a pixel by pixel basis; the dose difference, and the distance to agreement. By providing acceptance criteria (e.g. 3%, 3 mm), the function will find the most appropriate match within its two degrees of freedom. For complex dynamic treatments such as IMRT or VMAT it is important to verify the dose delivery in a time dependent manner and so a gamma evaluation that includes a degree of freedom in the time domain via a third parameter, time to agreement, is presented here. A C++ (mex) based gamma function was created that could be run on either CPU and GPU computing platforms that would allow a degree of freedom in the time domain. Simple test cases were created in both 2D and 3D comprising of simple geometrical shapes with well-defined boundaries varying over time. Changes of varying magnitude in either space or time were introduced and repeated gamma analyses were performed varying the criteria. A clinical VMAT case was also included, artificial air bubbles of varying size were introduced to a patient geometry, along with shifts of varying magnitude in treatment time. For all test cases where errors in distance, dose or time were introduced, the time dependent gamma evaluation could accurately highlight the errors. The time dependent gamma function presented here allows time to be included as a degree of freedom in gamma evaluations. The function allows for 2D and 3D data sets which are varying over time to be compared using appropriate criteria without penalising minor offsets of subsequent radiation

  16. Data-driven modeling and real-time distributed control for energy efficient manufacturing systems

    International Nuclear Information System (INIS)

    Zou, Jing; Chang, Qing; Arinez, Jorge; Xiao, Guoxian

    2017-01-01

    As manufacturers face the challenges of increasing global competition and energy saving requirements, it is imperative to seek out opportunities to reduce energy waste and overall cost. In this paper, a novel data-driven stochastic manufacturing system modeling method is proposed to identify and predict energy saving opportunities and their impact on production. A real-time distributed feedback production control policy, which integrates the current and predicted system performance, is established to improve the overall profit and energy efficiency. A case study is presented to demonstrate the effectiveness of the proposed control policy. - Highlights: • A data-driven stochastic manufacturing system model is proposed. • Real-time system performance and energy saving opportunity identification method is developed. • Prediction method for future potential system performance and energy saving opportunity is developed. • A real-time distributed feedback control policy is established to improve energy efficiency and overall system profit.

  17. Arrival time and incidence angle distributions of extensive air showers (EAS) muons

    International Nuclear Information System (INIS)

    Brancus, I.M.; Duma, M.; Vulpescu, B.; Foeller, M.; Rebel, H.; Voelker, G.; Chilingarian, A.A.

    1995-01-01

    The arrival time distributions of the muons can be related to the longitudinal EAS development and may provide additional information about the nature of the primary. Based on EAS simulations using the Monte-Carlo code CORSIKA, the correlations between arrival time and incidence angle distributions have been investigated in a case of a set of ideal detectors (10 m x 10 m) placed at various distances from the shower core. Applying advanced statistical techniques based on Bayes decision rule and non-parametric multivariate analysing methods it turns out that the correlations of muon arrival time and incidence angle at various separating distances of about 50 m exhibit promising features for mass discrimination (author)

  18. Multi-Time Scale Control of Demand Flexibility in Smart Distribution Networks

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu P.; Myers, Kurt S.; Bak-Jensen, Birgitte

    2017-01-01

    , and distribution system operator’s perspectives. A hierarchical control architecture (HCA) comprising scheduling, coordinative, and adaptive layers is then designed to realize their coordinative goal. This is realized by integrating multi-time scale controls that work from a day-ahead scheduling up to real-time...... adaptive control. The performance of the developed method is investigated with high EV penetration in a typical residential distribution grid. The simulation results demonstrate that HCA efficiently utilizes demand flexibility stemming from EVs to solve grid unbalancing and congestions with simultaneous...... maximization of economic benefits to the participating actors. This is ensured by enabling EV participation in day-ahead, balancing, and regulation markets. For the given network configuration and pricing structure, HCA ensures the EV owners to get paid up to five times the cost they were paying without...

  19. Catching the tail: Empirical identification of the distribution of the value of travel time

    DEFF Research Database (Denmark)

    Börjesson, Maria; Fosgerau, Mogens; Algers, Staffan

    2012-01-01

    Recent methodological advances in discrete choice analysis in combination with certain stated choice experiments have allowed researchers to check empirically the identification of the distribution of latent variables such as the value of travel time (VTT). Lack of identification is likely...... to be common and the consequences are severe. E.g., the Danish value of time study found the 15% right tail of the VTT distribution to be unidentified, making it impossible to estimate the mean VTT without resorting to strong assumptions with equally strong impact on the resulting estimate. This paper analyses...... data generated from a similar choice experiment undertaken in Sweden during 2007–2008 in which the range of tradeoff values between time and money was significantly increased relative to the Danish experiment. The results show that this change allowed empirical identification of effectively the entire...

  20. Anthropogenic CO2 in the oceans estimated using transit time distributions

    International Nuclear Information System (INIS)

    Waugh, D.W.; McNeil, B.I.

    2006-01-01

    The distribution of anthropogenic carbon (Cant) in the oceans is estimated using the transit time distribution (TTD) method applied to global measurements of chlorofluorocarbon-12 (CFC12). Unlike most other inference methods, the TTD method does not assume a single ventilation time and avoids the large uncertainty incurred by attempts to correct for the large natural carbon background in dissolved inorganic carbon measurements. The highest concentrations and deepest penetration of anthropogenic carbon are found in the North Atlantic and Southern Oceans. The estimated total inventory in 1994 is 134 Pg-C. To evaluate uncertainties the TTD method is applied to output from an ocean general circulation model (OGCM) and compared the results to the directly simulated Cant. Outside of the Southern Ocean the predicted Cant closely matches the directly simulated distribution, but in the Southern Ocean the TTD concentrations are biased high due to the assumption of 'constant disequilibrium'. The net result is a TTD overestimate of the global inventory by about 20%. Accounting for this bias and other centred uncertainties, an inventory range of 94-121 Pg-C is obtained. This agrees with the inventory of Sabine et al., who applied the DeltaC* method to the same data. There are, however, significant differences in the spatial distributions: The TTD estimates are smaller than DeltaC* in the upper ocean and larger at depth, consistent with biases expected in DeltaC* given its assumption of a single parcel ventilation time

  1. Real-Time Simulation and Hardware-in-the-Loop Testbed for Distribution Synchrophasor Applications

    Directory of Open Access Journals (Sweden)

    Matthias Stifter

    2018-04-01

    Full Text Available With the advent of Distribution Phasor Measurement Units (D-PMUs and Micro-Synchrophasors (Micro-PMUs, the situational awareness in power distribution systems is going to the next level using time-synchronization. However, designing, analyzing, and testing of such accurate measurement devices are still challenging. Due to the lack of available knowledge and sufficient history for synchrophasors’ applications at the power distribution level, the realistic simulation, and validation environments are essential for D-PMU development and deployment. This paper presents a vendor agnostic PMU real-time simulation and hardware-in-the-Loop (PMU-RTS-HIL testbed, which helps in multiple PMUs validation and studies. The network of real and virtual PMUs was built in a full time-synchronized environment for PMU applications’ validation. The proposed testbed also includes an emulated communication network (CNS layer to replicate bandwidth, packet loss and collisions conditions inherent to the PMUs data streams’ issues. Experimental results demonstrate the flexibility and scalability of the developed PMU-RTS-HIL testbed by producing large amounts of measurements under typical normal and abnormal distribution grid operation conditions.

  2. From heavy-tailed to exponential distribution of interevent time in cellphone top-up behavior

    Science.gov (United States)

    Wang, Peng; Ma, Qiang

    2017-05-01

    Cellphone top-up is a kind of activities, to a great extent, driven by individual consumption rather than personal interest and this behavior should be stable in common sense. However, our researches find there are heavy-tails both in interevent time distribution and purchase frequency distribution at the global level. Moreover, we find both memories of interevent time and unit price series are negative, which is different from previous bursty activities. We divide individuals into five groups according to the purchase frequency and the average unit price respectively. Then, the group analysis shows some significant heterogeneity in this behavior. On one hand, we obtain only the individuals with high purchase frequency have the heavy-tailed nature in interevent time distribution. On the contrary, the negative memory is only caused by low purchase-frequency individuals without burstiness. On the other hand, the individuals with different preferential price also have different power-law exponents at the group level and there is no data collapse after rescaling between these distributions. Our findings produce the evidence for the significant heterogeneity of human activity in many aspects.

  3. The application of convolution-based statistical model on the electrical breakdown time delay distributions in neon

    International Nuclear Information System (INIS)

    Maluckov, Cedomir A.; Karamarkovic, Jugoslav P.; Radovic, Miodrag K.; Pejovic, Momcilo M.

    2004-01-01

    The convolution-based model of the electrical breakdown time delay distribution is applied for statistical analysis of experimental results obtained in neon-filled diode tube at 6.5 mbar. At first, the numerical breakdown time delay density distributions are obtained by stochastic modeling as the sum of two independent random variables, the electrical breakdown statistical time delay with exponential, and discharge formative time with Gaussian distribution. Then, the single characteristic breakdown time delay distribution is obtained as the convolution of these two random variables with previously determined parameters. These distributions show good correspondence with the experimental distributions, obtained on the basis of 1000 successive and independent measurements. The shape of distributions is investigated, and corresponding skewness and kurtosis are plotted, in order to follow the transition from Gaussian to exponential distribution

  4. A FEMTOSECOND-LEVEL FIBER-OPTICS TIMING DISTRIBUTION SYSTEM USING FREQUENCY-OFFSET INTERFEROMETRY

    International Nuclear Information System (INIS)

    Staples, J.W.; Byrd, J.; Doolittle, L.; Huang, G.; Wilcox, R.

    2008-01-01

    An optical fiber-based frequency and timing distribution system based on the principle of heterodyne interferometry has been in development at LBNL for several years. The fiber drift corrector has evolved from an RF-based to an optical-based system, from mechanical correctors (piezo and optical trombone) to fully electronic, and the electronics from analog to fully digital, all using inexpensive off-the-shelf commodity fiber components. Short-term optical phase jitter and long-term phase drift are both in the femtosecond range over distribution paths of 2 km or more

  5. Time evolution analysis of the electron distribution in Thomson/Compton back-scattering

    International Nuclear Information System (INIS)

    Petrillo, V.; Bacci, A.; Curatolo, C.; Maroli, C.; Serafini, L.; Rossi, A. R.

    2013-01-01

    We present the time evolution of the energy distribution of a relativistic electron beam after the Compton back-scattering with a counter-propagating laser field, performed in the framework of the Quantum Electrodynamics, by means of the code CAIN. As the correct angular distribution of the spontaneous emission is accounted, the main effect is the formation of few stripes, followed by the diffusion of the more energetic particles toward lower values in the longitudinal phase space. The Chapman-Kolmogorov master equation gives results in striking agreement with the numerical ones. An experiment on the Thomson source at SPARC-LAB is proposed

  6. Delay-dependent exponential stability for neural networks with discrete and distributed time-varying delays

    International Nuclear Information System (INIS)

    Zhu Xunlin; Wang Youyi

    2009-01-01

    This Letter studies the exponential stability for a class of neural networks (NNs) with both discrete and distributed time-varying delays. Under weaker assumptions on the activation functions, by defining a more general type of Lyapunov functionals and developing a new convex combination technique, new less conservative and less complex stability criteria are established to guarantee the global exponential stability of the discussed NNs. The obtained conditions are dependent on both discrete and distributed delays, are expressed in terms of linear matrix inequalities (LMIs), and contain fewer decision variables. Numerical examples are given to illustrate the effectiveness and the less conservatism of the proposed conditions.

  7. Time-frequency representation of a highly nonstationary signal via the modified Wigner distribution

    Science.gov (United States)

    Zoladz, T. F.; Jones, J. H.; Jong, J.

    1992-01-01

    A new signal analysis technique called the modified Wigner distribution (MWD) is presented. The new signal processing tool has been very successful in determining time frequency representations of highly non-stationary multicomponent signals in both simulations and trials involving actual Space Shuttle Main Engine (SSME) high frequency data. The MWD departs from the classic Wigner distribution (WD) in that it effectively eliminates the cross coupling among positive frequency components in a multiple component signal. This attribute of the MWD, which prevents the generation of 'phantom' spectral peaks, will undoubtedly increase the utility of the WD for real world signal analysis applications which more often than not involve multicomponent signals.

  8. Extracting message inter-departure time distributions from the human electroencephalogram.

    Directory of Open Access Journals (Sweden)

    Bratislav Mišić

    2011-06-01

    Full Text Available The complex connectivity of the cerebral cortex is a topic of much study, yet the link between structure and function is still unclear. The processing capacity and throughput of information at individual brain regions remains an open question and one that could potentially bridge these two aspects of neural organization. The rate at which information is emitted from different nodes in the network and how this output process changes under different external conditions are general questions that are not unique to neuroscience, but are of interest in multiple classes of telecommunication networks. In the present study we show how some of these questions may be addressed using tools from telecommunications research. An important system statistic for modeling and performance evaluation of distributed communication systems is the time between successive departures of units of information at each node in the network. We describe a method to extract and fully characterize the distribution of such inter-departure times from the resting-state electroencephalogram (EEG. We show that inter-departure times are well fitted by the two-parameter Gamma distribution. Moreover, they are not spatially or neurophysiologically trivial and instead are regionally specific and sensitive to the presence of sensory input. In both the eyes-closed and eyes-open conditions, inter-departure time distributions were more dispersed over posterior parietal channels, close to regions which are known to have the most dense structural connectivity. The biggest differences between the two conditions were observed at occipital sites, where inter-departure times were significantly more variable in the eyes-open condition. Together, these results suggest that message departure times are indicative of network traffic and capture a novel facet of neural activity.

  9. Analysis of Distributed Consensus Time Synchronization with Gaussian Delay over Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xiong Gang

    2009-01-01

    Full Text Available This paper presents theoretical results on the convergence of the distributed consensus timing synchronization (DCTS algorithm for wireless sensor networks assuming general Gaussian delay between nodes. The asymptotic expectation and mean square of the global synchronization error are computed. The results lead to the definition of a time delay balanced network in which average timing consensus between nodes can be achieved despite random delays. Several structured network architectures are studied as examples, and their associated simulation results are used to validate analytical findings.

  10. Use of common time base for checkpointing and rollback recovery in a distributed system

    Science.gov (United States)

    Ramanathan, Parameswaran; Shin, Kang G.

    1993-01-01

    An approach to checkpointing and rollback recovery in a distributed computing system using a common time base is proposed. A common time base is established in the system using a hardware clock synchronization algorithm. This common time base is coupled with the idea of pseudo-recovery points to develop a checkpointing algorithm that has the following advantages: reduced wait for commitment for establishing recovery lines, fewer messages to be exchanged, and less memory requirement. These advantages are assessed quantitatively by developing a probabilistic model.

  11. Probability distribution of wave packet delay time for strong overlapping of resonance levels

    International Nuclear Information System (INIS)

    Lyuboshits, V.L.

    1983-01-01

    Time behaviour of nuclear reactions in the case of high level densities is investigated basing on the theory of overlapping resonances. In the framework of a model of n equivalent channels an analytical expression is obtained for the probability distribution function for wave packet delay time at the compound nucleus production. It is shown that at strong overlapping of the resonance levels the relative fluctuation of the delay time is small at the stage of compound nucleus production. A possible increase in the duration of nuclear reactions with the excitation energy rise is discussed

  12. Investigation of unstable periodic space-time states in distributed active system with supercritical current

    International Nuclear Information System (INIS)

    Koronovskij, A.A.; Rempen, I.S.; Khramov, A.E.

    2003-01-01

    The set of the unstable periodic space-time states, characterizing the chaotic space-time dynamics of the electron beam with the supercritical current in the Pierce diode is discussed. The Lyapunov indicators of the revealed instable space-time states of the chaotic dynamics of the distributed self-excited system are calculated. It is shown that change in the set of the unstable periodic states in dependence on the Pierce parameter is determined by change in the various orbits stability, which is demonstrated by the values of senior Lyapunov unstable state index [ru

  13. [Live birth distribution by time and place from 1981 to 1998 in Japan].

    Science.gov (United States)

    Matsushima, Noriko; Morita, Noriko; Ogata, Nozomi; Saeki, Keigo; Matsuda, Ryozo; Kurumatani, Norio

    2003-01-01

    To investigate the diurnal rhythm of live births labored spontaneously, and the effects of obstetric intervention on birth time distributions. The data of live births tabulated by time (one-hour intervals), date and birthplace throughout Japan between 1981 and 1998 were obtained with permission from the former Ministry of Health and Welfare. Together with an investigation of hourly birth numbers by place in each year, an annual transition of hourly birth rates in medical institutions and the diurnal rhythm of birth numbers in maternity homes and at home were analyzed using regression analysis. In every calendar year studied the hourly live birth numbers at hospitals showed a single-peak distribution pattern with maximum values at 13:00-15:00. The annual transition of hourly birth rates showed a 10% (birth numbers base) decrease in the 11:00-13:00 period in 1998 as compared with that in 1981, while there was a corresponding increase of 8% in the 13:00-15:00 period. Hourly birth numbers at clinics showed a double-peak distribution pattern with maximum values during the 11:00-12:00 and 14:00-15:00 periods in early 1980, while a single-peak distribution with a maximum value during the 13:00-15:00 period appeared in 1989 and has remained thereafter. Hourly birth rates (birth numbers base) increased by over 6% in the 13:00-15:00 and 17:00-20:00 periods over the past 18 years, while they decreased by 10% in the 9:00-13:00 period. The results at maternity homes were clearly different from those at hospitals and clinics. The live birth numbers totaled for the 18 years showed a double-phase distribution with a maximum value in the 6:00-7:00 period and a minimum value in the 19:00-20:00 period. The best-fit regression model for the obtained data was a sine curve with a maximum value at 6:00 (coefficient of determination 0.97). Hourly distributions of live births at home also fitted best to a since curve with the maximum value again at 6:00 (coefficient of determination 0

  14. Bi-Directional Brillouin Optical Time Domain Analyzer System for Long Range Distributed Sensing.

    Science.gov (United States)

    Guo, Nan; Wang, Liang; Wang, Jie; Jin, Chao; Tam, Hwa-Yaw; Zhang, A Ping; Lu, Chao

    2016-12-16

    We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes.

  15. Bi-Directional Brillouin Optical Time Domain Analyzer System for Long Range Distributed Sensing

    Science.gov (United States)

    Guo, Nan; Wang, Liang; Wang, Jie; Jin, Chao; Tam, Hwa-Yaw; Zhang, A. Ping; Lu, Chao

    2016-01-01

    We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes. PMID:27999250

  16. Comparison of Muon Arrival Time Distributions measured in KASCADE Experiment with Monte Carlo Simulations

    International Nuclear Information System (INIS)

    Badea, A.F.; Brancus, I.M.; Haeusler, R.; Rebel, H.

    2000-01-01

    The muon arrival time distributions of Extensive Air Showers (EAS) have been studied in KASCADE experiment by data collected in the period October 1997 - April 1999 with more than 3.4 millions of reconstructed showers. The radial distance of the shower center from the central detector has been selected smaller than 110 m. The experimental muon arrival time distributions are compared with simulations of the air shower development, calculated with the Monte Carlo air shower simulation program CORSIKA. The actual calculations are based on the QGSJET model and cover an energy range of 5·10 14 - 3.06·10 16 eV (divided in 7 overlapping energy bins) and a zenith angle range of 0 angle - 40 angle. They are performed for three mass groups: H = light group, O = CNO group, Fe = heavy group) with an energy distribution of a spectral index of -2.7. The simulations comprise a set of ≅ 2000$ showers for each case, except for the bins of the highest energies (6.51·10 15 - 1.82·10 16 eV with ≅1000$ simulated showers and 1.09·10 16 - 3.06·10 16 eV with ≅ 500 simulated showers). The response of the KASCADE detector system and the timing qualities have been simulated using the CRES program, dedicatedly developed by the KASCADE group on the basis of the GEANT code. The particles of the simulated EAS are tracked through the detector setup and the timing response of the detectors are recorded for various core distances from the central detector facilities. Particularly, it should be noted that the timing depends on the energy deposit in the scintillation detectors and on the multiplicities of the muon samples spanning the arrival time distributions of the single EAS. Such effects slightly distorts the measured time distributions and have been corrected by introducing a corresponding correction procedure. The dependence of the experimental and simulated median time values on the N μ tr range, as being proportional to the primary energy, is presented. The good agreement of the

  17. Interevent time distributions of human multi-level activity in a virtual world

    Science.gov (United States)

    Mryglod, O.; Fuchs, B.; Szell, M.; Holovatch, Yu.; Thurner, S.

    2015-02-01

    Studying human behavior in virtual environments provides extraordinary opportunities for a quantitative analysis of social phenomena with levels of accuracy that approach those of the natural sciences. In this paper we use records of player activities in the massive multiplayer online game Pardus over 1238 consecutive days, and analyze dynamical features of sequences of actions of players. We build on previous work where temporal structures of human actions of the same type were quantified, and provide an empirical understanding of human actions of different types. This study of multi-level human activity can be seen as a dynamic counterpart of static multiplex network analysis. We show that the interevent time distributions of actions in the Pardus universe follow highly non-trivial distribution functions, from which we extract action-type specific characteristic 'decay constants'. We discuss characteristic features of interevent time distributions, including periodic patterns on different time scales, bursty dynamics, and various functional forms on different time scales. We comment on gender differences of players in emotional actions, and find that while males and females act similarly when performing some positive actions, females are slightly faster for negative actions. We also observe effects on the age of players: more experienced players are generally faster in making decisions about engaging in and terminating enmity and friendship, respectively.

  18. SU-E-T-758: To Determine the Source Dwell Positions of HDR Brachytherapy Using 2D 729 Ion Chamber Array

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Syam [Malabar Cancer Centre, Kannur, Kerala (India); Sitha [University of Calicut, Calicut, Kerala (India)

    2015-06-15

    Purpose: Determination of source dwell positions of HDR brachytherapy using 2D 729 ion chamber array Methods: Nucletron microselectron HDR and PTW 2D array were used for the study. Different dwell positions were assigned in the HDR machine. Rigid interstitial needles and vaginal applicator were positioned on the 2D array. The 2D array was exposed for this programmed dwell positions. The positional accuracy of the source was analyzed after the irradiation of the 2D array. This was repeated for different dwell positions. Different test plans were transferred from the Oncentra planning system and irradiated with the same applicator position on the 2D array. The results were analyzed using the in house developed excel program. Results: Assigned dwell positions versus corresponding detector response were analyzed. The results show very good agreement with the film measurements. No significant variation found between the planned and measured dwell positions. Average dose response with 2D array between the planned and nearby dwell positions was found to be 0.0804 Gy for vaginal cylinder applicator and 0.1234 Gy for interstitial rigid needles. Standard deviation between the doses for all the measured dwell positions for interstitial rigid needle for 1 cm spaced positions were found to be 0.33 and 0.37 for 2cm spaced dwell positions. For intracavitory vaginal applicator this was found to be 0.21 for 1 cm spaced dwell positions and 0.06 for 2cm spaced dwell positions. Intracavitory test plans reproduced on the 2D array with the same applicator positions shows the ideal dose distribution with the TPS planned. Conclusion: 2D array is a good tool for determining the dwell position of HDR brachytherapy. With the in-house developed program in excel it is easy and accurate. The traditional way with film analysis can be replaced by this method, as the films will be more costly.

  19. SU-E-T-758: To Determine the Source Dwell Positions of HDR Brachytherapy Using 2D 729 Ion Chamber Array

    International Nuclear Information System (INIS)

    Kumar, Syam; Sitha

    2015-01-01

    Purpose: Determination of source dwell positions of HDR brachytherapy using 2D 729 ion chamber array Methods: Nucletron microselectron HDR and PTW 2D array were used for the study. Different dwell positions were assigned in the HDR machine. Rigid interstitial needles and vaginal applicator were positioned on the 2D array. The 2D array was exposed for this programmed dwell positions. The positional accuracy of the source was analyzed after the irradiation of the 2D array. This was repeated for different dwell positions. Different test plans were transferred from the Oncentra planning system and irradiated with the same applicator position on the 2D array. The results were analyzed using the in house developed excel program. Results: Assigned dwell positions versus corresponding detector response were analyzed. The results show very good agreement with the film measurements. No significant variation found between the planned and measured dwell positions. Average dose response with 2D array between the planned and nearby dwell positions was found to be 0.0804 Gy for vaginal cylinder applicator and 0.1234 Gy for interstitial rigid needles. Standard deviation between the doses for all the measured dwell positions for interstitial rigid needle for 1 cm spaced positions were found to be 0.33 and 0.37 for 2cm spaced dwell positions. For intracavitory vaginal applicator this was found to be 0.21 for 1 cm spaced dwell positions and 0.06 for 2cm spaced dwell positions. Intracavitory test plans reproduced on the 2D array with the same applicator positions shows the ideal dose distribution with the TPS planned. Conclusion: 2D array is a good tool for determining the dwell position of HDR brachytherapy. With the in-house developed program in excel it is easy and accurate. The traditional way with film analysis can be replaced by this method, as the films will be more costly

  20. Primary evaluation of the radon situation in dwellings in Saxony by long-time integrating measurements, comparison of the results with short-time measurements and determination of the radon activity concentration in the ground of the land; Erstbewertung zur Radonsituation von Haeusern im Freistaat Sachsen mittels langzeitintegrierenden Messungen, Vergleich der Ergebnisse mit Kurzzeitmessungen und Erfassung der Radon-Aktivitaetskonzentration in der Bodenluft der Grundstuecke

    Energy Technology Data Exchange (ETDEWEB)

    Alisch-Mark, M.; Keck, D.; Preusse, W.; Taube, A.; Busch, H.; Heinrich, T. [Staatliche Betriebsgesellschaft fuer Umwelt und Landwirtschaft, Sachsen (Germany)

    2016-07-01

    A measurement program was carried out for primary evaluation of dwellings in terms of radon situation. Short-time measurements were compared with annual averages and checked for their suitability for forecasting the annual averages. In 89% of the cases studied, the average annual values could be predicted by short-time measurements, differences were observed depending on the date of the short-time measure. In addition, radon activity concentrations were determined in the soil air in the ground and compared with the expected areas of forecasting map of Saxony. Discrepancies were found primarily in areas which are marked by a smallscale geology. The data obtained showed that the geogenic radon potential and the year of construction of the house represent factors influencing the probability of exceedance of the reference value of 300 Bq/m{sup 3}.

  1. The mathematical formula of the intravaginal ejaculation latency time (IELT distribution of lifelong premature ejaculation differs from the IELT distribution formula of men in the general male population

    Directory of Open Access Journals (Sweden)

    Paddy K.C. Janssen

    2016-03-01

    Full Text Available Purpose: To find the most accurate mathematical description of the intravaginal ejaculation latency time (IELT distribution in the general male population. Materials and Methods: We compared the fitness of various well-known mathematical distributions with the IELT distribution of two previously published stopwatch studies of the Caucasian general male population and a stopwatch study of Dutch Caucasian men with lifelong premature ejaculation (PE. The accuracy of fitness is expressed by the Goodness of Fit (GOF. The smaller the GOF, the more accurate is the fitness. Results: The 3 IELT distributions are gamma distributions, but the IELT distribution of lifelong PE is another gamma distribution than the IELT distribution of men in the general male population. The Lognormal distribution of the gamma distributions most accurately fits the IELT distribution of 965 men in the general population, with a GOF of 0.057. The Gumbel Max distribution most accurately fits the IELT distribution of 110 men with lifelong PE with a GOF of 0.179. There are more men with lifelong PE ejaculating within 30 and 60 seconds than can be extrapolated from the probability density curve of the Lognormal IELT distribution of men in the general population. Conclusions: Men with lifelong PE have a distinct IELT distribution, e.g., a Gumbel Max IELT distribution, that can only be retrieved from the general male population Lognormal IELT distribution when thousands of men would participate in a IELT stopwatch study. The mathematical formula of the Lognormal IELT distribution is useful for epidemiological research of the IELT.

  2. The mathematical formula of the intravaginal ejaculation latency time (IELT) distribution of lifelong premature ejaculation differs from the IELT distribution formula of men in the general male population

    Science.gov (United States)

    Janssen, Paddy K.C.

    2016-01-01

    Purpose To find the most accurate mathematical description of the intravaginal ejaculation latency time (IELT) distribution in the general male population. Materials and Methods We compared the fitness of various well-known mathematical distributions with the IELT distribution of two previously published stopwatch studies of the Caucasian general male population and a stopwatch study of Dutch Caucasian men with lifelong premature ejaculation (PE). The accuracy of fitness is expressed by the Goodness of Fit (GOF). The smaller the GOF, the more accurate is the fitness. Results The 3 IELT distributions are gamma distributions, but the IELT distribution of lifelong PE is another gamma distribution than the IELT distribution of men in the general male population. The Lognormal distribution of the gamma distributions most accurately fits the IELT distribution of 965 men in the general population, with a GOF of 0.057. The Gumbel Max distribution most accurately fits the IELT distribution of 110 men with lifelong PE with a GOF of 0.179. There are more men with lifelong PE ejaculating within 30 and 60 seconds than can be extrapolated from the probability density curve of the Lognormal IELT distribution of men in the general population. Conclusions Men with lifelong PE have a distinct IELT distribution, e.g., a Gumbel Max IELT distribution, that can only be retrieved from the general male population Lognormal IELT distribution when thousands of men would participate in a IELT stopwatch study. The mathematical formula of the Lognormal IELT distribution is useful for epidemiological research of the IELT. PMID:26981594

  3. A New Quantum Key Distribution Scheme Based on Frequency and Time Coding

    International Nuclear Information System (INIS)

    Chang-Hua, Zhu; Chang-Xing, Pei; Dong-Xiao, Quan; Jing-Liang, Gao; Nan, Chen; Yun-Hui, Yi

    2010-01-01

    A new scheme of quantum key distribution (QKD) using frequency and time coding is proposed, in which the security is based on the frequency-time uncertainty relation. In this scheme, the binary information sequence is encoded randomly on either the central frequency or the time delay of the optical pulse at the sender. The central frequency of the single photon pulse is set as ω 1 for bit 0 and set as ω 2 for bit 1 when frequency coding is selected. However, the single photon pulse is not delayed for bit 0 and is delayed in τ for 1 when time coding is selected. At the receiver, either the frequency or the time delay of the pulse is measured randomly, and the final key is obtained after basis comparison, data reconciliation and privacy amplification. With the proposed method, the effect of the noise in the fiber channel and environment on the QKD system can be reduced effectively

  4. Time difference of arrival estimation of microseismic signals based on alpha-stable distribution

    Science.gov (United States)

    Jia, Rui-Sheng; Gong, Yue; Peng, Yan-Jun; Sun, Hong-Mei; Zhang, Xing-Li; Lu, Xin-Ming

    2018-05-01

    Microseismic signals are generally considered to follow the Gauss distribution. A comparison of the dynamic characteristics of sample variance and the symmetry of microseismic signals with the signals which follow α-stable distribution reveals that the microseismic signals have obvious pulse characteristics and that the probability density curve of the microseismic signal is approximately symmetric. Thus, the hypothesis that microseismic signals follow the symmetric α-stable distribution is proposed. On the premise of this hypothesis, the characteristic exponent α of the microseismic signals is obtained by utilizing the fractional low-order statistics, and then a new method of time difference of arrival (TDOA) estimation of microseismic signals based on fractional low-order covariance (FLOC) is proposed. Upon applying this method to the TDOA estimation of Ricker wavelet simulation signals and real microseismic signals, experimental results show that the FLOC method, which is based on the assumption of the symmetric α-stable distribution, leads to enhanced spatial resolution of the TDOA estimation relative to the generalized cross correlation (GCC) method, which is based on the assumption of the Gaussian distribution.

  5. Choice Overload, Satisficing Behavior, and Price Distribution in a Time Allocation Model

    Directory of Open Access Journals (Sweden)

    Francisco Álvarez

    2014-01-01

    Full Text Available Recent psychological research indicates that consumers that search exhaustively for the best option of a market product—known as maximizers—eventually feel worse than consumers who just look for something good enough—called satisficers. We formulate a time allocation model to explore the relationship between different distributions of prices of the product and the satisficing behavior and the related welfare of the consumer. We show numerically that, as the number of options becomes large, the maximizing behavior produces less and less welfare and eventually leads to choice paralysis—these are effects of choice overload—whereas satisficing conducts entail higher levels of satisfaction and do not end up in paralysis. For different price distributions, we provide consistent evidence that maximizers are better off for a low number of options, whereas satisficers are better off for a sufficiently large number of options. We also show how the optimal satisficing behavior is affected when the underlying price distribution varies. We provide evidence that the mean and the dispersion of a symmetric distribution of prices—but not the shape of the distribution—condition the satisficing behavior of consumers. We also show that this need not be the case for asymmetric distributions.

  6. Analysis of discrete and continuous distributions of ventilatory time constants from dynamic computed tomography

    International Nuclear Information System (INIS)

    Doebrich, Marcus; Markstaller, Klaus; Karmrodt, Jens; Kauczor, Hans-Ulrich; Eberle, Balthasar; Weiler, Norbert; Thelen, Manfred; Schreiber, Wolfgang G

    2005-01-01

    In this study, an algorithm was developed to measure the distribution of pulmonary time constants (TCs) from dynamic computed tomography (CT) data sets during a sudden airway pressure step up. Simulations with synthetic data were performed to test the methodology as well as the influence of experimental noise. Furthermore the algorithm was applied to in vivo data. In five pigs sudden changes in airway pressure were imposed during dynamic CT acquisition in healthy lungs and in a saline lavage ARDS model. The fractional gas content in the imaged slice (FGC) was calculated by density measurements for each CT image. Temporal variations of the FGC were analysed assuming a model with a continuous distribution of exponentially decaying time constants. The simulations proved the feasibility of the method. The influence of experimental noise could be well evaluated. Analysis of the in vivo data showed that in healthy lungs ventilation processes can be more likely characterized by discrete TCs whereas in ARDS lungs continuous distributions of TCs are observed. The temporal behaviour of lung inflation and deflation can be characterized objectively using the described new methodology. This study indicates that continuous distributions of TCs reflect lung ventilation mechanics more accurately compared to discrete TCs

  7. Linear time algorithms to construct populations fitting multiple constraint distributions at genomic scales.

    Science.gov (United States)

    Siragusa, Enrico; Haiminen, Niina; Utro, Filippo; Parida, Laxmi

    2017-10-09

    Computer simulations can be used to study population genetic methods, models and parameters, as well as to predict potential outcomes. For example, in plant populations, predicting the outcome of breeding operations can be studied using simulations. In-silico construction of populations with pre-specified characteristics is an important task in breeding optimization and other population genetic studies. We present two linear time Simulation using Best-fit Algorithms (SimBA) for two classes of problems where each co-fits two distributions: SimBA-LD fits linkage disequilibrium and minimum allele frequency distributions, while SimBA-hap fits founder-haplotype and polyploid allele dosage distributions. An incremental gap-filling version of previously introduced SimBA-LD is here demonstrated to accurately fit the target distributions, allowing efficient large scale simulations. SimBA-hap accuracy and efficiency is demonstrated by simulating tetraploid populations with varying numbers of founder haplotypes, we evaluate both a linear time greedy algoritm and an optimal solution based on mixed-integer programming. SimBA is available on http://researcher.watson.ibm.com/project/5669.

  8. Statistical distributions of avalanche size and waiting times in an inter-sandpile cascade model

    Science.gov (United States)

    Batac, Rene; Longjas, Anthony; Monterola, Christopher

    2012-02-01

    Sandpile-based models have successfully shed light on key features of nonlinear relaxational processes in nature, particularly the occurrence of fat-tailed magnitude distributions and exponential return times, from simple local stress redistributions. In this work, we extend the existing sandpile paradigm into an inter-sandpile cascade, wherein the avalanches emanating from a uniformly-driven sandpile (first layer) is used to trigger the next (second layer), and so on, in a successive fashion. Statistical characterizations reveal that avalanche size distributions evolve from a power-law p(S)≈S-1.3 for the first layer to gamma distributions p(S)≈Sαexp(-S/S0) for layers far away from the uniformly driven sandpile. The resulting avalanche size statistics is found to be associated with the corresponding waiting time distribution, as explained in an accompanying analytic formulation. Interestingly, both the numerical and analytic models show good agreement with actual inventories of non-uniformly driven events in nature.

  9. Features of the use of time-frequency distributions for controlling the mixture-producing aggregate

    Science.gov (United States)

    Fedosenkov, D. B.; Simikova, A. A.; Fedosenkov, B. A.

    2018-05-01

    The paper submits and argues the information on filtering properties of the mixing unit as a part of the mixture-producing aggregate. Relevant theoretical data concerning a channel transfer function of the mixing unit and multidimensional material flow signals are adduced here. Note that ordinary one-dimensional material flow signals are defined in terms of time-frequency distributions of Cohen’s class representations operating with Gabor wavelet functions. Two time-frequencies signal representations are written about in the paper to show how one can solve controlling problems as applied to mixture-producing systems: they are the so-called Rihaczek and Wigner-Ville distributions. In particular, the latter illustrates low-pass filtering properties that are practically available in any of low-pass elements of a physical system.

  10. Decentralized Observer with a Consensus Filter for Distributed Discrete-Time Linear Systems

    Science.gov (United States)

    Acikmese, Behcet; Mandic, Milan

    2011-01-01

    This paper presents a decentralized observer with a consensus filter for the state observation of a discrete-time linear distributed systems. In this setup, each agent in the distributed system has an observer with a model of the plant that utilizes the set of locally available measurements, which may not make the full plant state detectable. This lack of detectability is overcome by utilizing a consensus filter that blends the state estimate of each agent with its neighbors' estimates. We assume that the communication graph is connected for all times as well as the sensing graph. It is proven that the state estimates of the proposed observer asymptotically converge to the actual plant states under arbitrarily changing, but connected, communication and sensing topologies. As a byproduct of this research, we also obtained a result on the location of eigenvalues, the spectrum, of the Laplacian for a family of graphs with self-loops.

  11. Methods of Run-Time Error Detection in Distributed Process Control Software

    DEFF Research Database (Denmark)

    Drejer, N.

    In this thesis, methods of run-time error detection in application software for distributed process control is designed. The error detection is based upon a monitoring approach in which application software is monitored by system software during the entire execution. The thesis includes definition...... and constraint evaluation is designed for the modt interesting error types. These include: a) semantical errors in data communicated between application tasks; b) errors in the execution of application tasks; and c) errors in the timing of distributed events emitted by the application software. The design...... of error detection methods includes a high level software specification. this has the purpose of illustrating that the designed can be used in practice....

  12. Design optimization for security-and safety-critical distributed real-time applications

    DEFF Research Database (Denmark)

    Jiang, Wei; Pop, Paul; Jiang, Ke

    2016-01-01

    requirements on confidentiality of messages, task replication is used to enhance system reliability, and dynamic voltage and frequency scaling is used for energy efficiency of tasks. It is challenging to address these factors simultaneously, e.g., better security protections need more computing resources......In this paper, we are interested in the design of real-time applications with security, safety, timing, and energy requirements. The applications are scheduled with cyclic scheduling, and are mapped on distributed heterogeneous architectures. Cryptographic services are deployed to satisfy security...... and consume more energy, while lower voltages and frequencies may impair schedulability and security, and also lead to reliability degradation. We introduce a vulnerability based method to quantify the security performance of communications on distributed systems. We then focus on determining the appropriate...

  13. SAFCM: A Security-Aware Feedback Control Mechanism for Distributed Real-Time Embedded Systems

    DEFF Research Database (Denmark)

    Ma, Yue; Jiang, Wei; Sang, Nan

    2012-01-01

    Distributed Real-time Embedded (DRE) systems are facing great challenges in networked, unpredictable and especially unsecured environments. In such systems, there is a strong need to enforce security on distributed computing nodes in order to guard against potential threats, while satisfying......-time systems, a multi-input multi-output feedback loop is designed and a model predictive controller is deployed based on an equation model that describes the dynamic behavior of the DRE systems. This control loop uses security level scaling to globally control the CPU utilization and security performance...... for the whole system. We propose a "security level" metric based on an evolution of cryptography algorithms used in embedded systems. Experimental results demonstrate that SAFCM not only has the excellent adaptivity compared to open-loop mechanism, but also has a better overall performance than PID control...

  14. Radon in dwellings and shelters in Zagreb

    International Nuclear Information System (INIS)

    Lokobauer, N.; Franic, Z.; Sencar, J.; Bauman, A.

    1994-01-01

    Since 1990, radon activity was measured in dwellings of Zagreb. In only small number of dwellings radon activity exceeded 100 Bq.m -3 . Since the inhabitants of Croatia have to stay in the facilities below the ground due to the war against Croatia, the paper gives also data on radon activity measured in the shelters and cellars in 1991. Measurements were performed using Kodak LR-115 detectors, type II. At several locations radon activity was measured with a silicon detector (Radhome). Radon values obtained for the shelters, cellars and dwellings at all locations were compared. With respect to children as most susceptable population group the paper gives data on radon activity for kindergartens and elementary schools (and its shelters) where children usually spend almost one-third to the day. (orig.)

  15. Recommended action levels for radon in dwellings

    International Nuclear Information System (INIS)

    1988-01-01

    The recommendation made by a group appointed by the Directorate of Public Health, arrives at the conclusion that radon in Norwegian dwellings implies a substantial health problem for the country. For this reason it is recommended that actions should be taken to reduce the radiation exposure from radon in Norway. Upper levels for such actions are set to 200 Bq/m 3 (radon in air of dwellings) for new contructions. For existing dwellings having concentrations of 200 - 800 Bq/m 3 , simple and unexpensive remedial actions to reduce levels are sufficient. When levels exceed 800 Bq/m 3 , more elaborate and costly actions are necessary. An evaluation of the extent of the radon problem in Norway is included, together with a survey of the cost and benefit involved in choosing various levels for remedial actions

  16. Exposure Time Distributions reveal Denitrification Rates along Groundwater Flow Path of an Agricultural Unconfined Aquifer

    Science.gov (United States)

    Kolbe, T.; Abbott, B. W.; Thomas, Z.; Labasque, T.; Aquilina, L.; Laverman, A.; Babey, T.; Marçais, J.; Fleckenstein, J. H.; Peiffer, S.; De Dreuzy, J. R.; Pinay, G.

    2016-12-01

    Groundwater contamination by nitrate is nearly ubiquitous in agricultural regions. Nitrate is highly mobile in groundwater and though it can be denitrified in the aquifer (reduced to inert N2 gas), this process requires the simultaneous occurrence of anoxia, an electron donor (e.g. organic carbon, pyrite), nitrate, and microorganisms capable of denitrification. In addition to this the ratio of the time groundwater spent in a denitrifying environment (exposure time) to the characteristic denitrification reaction time plays an important role, because denitrification can only occur if the exposure time is longer than the characteristic reaction time. Despite a long history of field studies and numerical models, it remains exceedingly difficult to measure or model exposure times in the subsurface at the catchment scale. To approach this problem, we developed a unified modelling approach combining measured environmental proxies with an exposure time based reactive transport model. We measured groundwater age, nitrogen and sulfur isotopes, and water chemistry from agricultural wells in an unconfined aquifer in Brittany, France, to quantify changes in nitrate concentration due to dilution and denitrification. Field data showed large differences in nitrate concentrations among wells, associated with differences in the exposure time distributions. By constraining a catchment-scale characteristic reaction time for denitrification with water chemistry proxies and exposure times, we were able to assess rates of denitrification along groundwater flow paths. This unified modeling approach is transferable to other catchments and could be further used to investigate how catchment structure and flow dynamics interact with biogeochemical processes such as denitrification.

  17. Accounting for detectability in fish distribution models: an approach based on time-to-first-detection

    Directory of Open Access Journals (Sweden)

    Mário Ferreira

    2015-12-01

    Full Text Available Imperfect detection (i.e., failure to detect a species when the species is present is increasingly recognized as an important source of uncertainty and bias in species distribution modeling. Although methods have been developed to solve this problem by explicitly incorporating variation in detectability in the modeling procedure, their use in freshwater systems remains limited. This is probably because most methods imply repeated sampling (≥ 2 of each location within a short time frame, which may be impractical or too expensive in most studies. Here we explore a novel approach to control for detectability based on the time-to-first-detection, which requires only a single sampling occasion and so may find more general applicability in freshwaters. The approach uses a Bayesian framework to combine conventional occupancy modeling with techniques borrowed from parametric survival analysis, jointly modeling factors affecting the probability of occupancy and the time required to detect a species. To illustrate the method, we modeled large scale factors (elevation, stream order and precipitation affecting the distribution of six fish species in a catchment located in north-eastern Portugal, while accounting for factors potentially affecting detectability at sampling points (stream depth and width. Species detectability was most influenced by depth and to lesser extent by stream width and tended to increase over time for most species. Occupancy was consistently affected by stream order, elevation and annual precipitation. These species presented a widespread distribution with higher uncertainty in tributaries and upper stream reaches. This approach can be used to estimate sampling efficiency and provide a practical framework to incorporate variations in the detection rate in fish distribution models.

  18. Time evolution of a Gaussian class of quasi-distribution functions under quadratic Hamiltonian.

    Science.gov (United States)

    Ginzburg, D; Mann, A

    2014-03-10

    A Lie algebraic method for propagation of the Wigner quasi-distribution function (QDF) under quadratic Hamiltonian was presented by Zoubi and Ben-Aryeh. We show that the same method can be used in order to propagate a rather general class of QDFs, which we call the "Gaussian class." This class contains as special cases the well-known Wigner, Husimi, Glauber, and Kirkwood-Rihaczek QDFs. We present some examples of the calculation of the time evolution of those functions.

  19. Residence Time Distribution (RTD) Prediction in Mixing Vessel via CFD Simulation Using Fluent: An Overview

    International Nuclear Information System (INIS)

    Mohd Rizal Mamat; Azraf Azman; Noraishah Othman

    2011-01-01

    A prototype mixing vessel has been developed by Industrial Technology Division and installed at a multiphase testing facility in MINT Tech Park. A task to investigate the mixing vessel performance using Computational Fluid Dynamics (CFD) has been undertaken using the available FLUENT software in Malaysian Nuclear Agency. This paper discusses the modeling and simulation done in obtaining the Residence Time Distribution (RTD) for the mixing vessel using FLUENT. (author)

  20. Obtaining location/arrival-time and location/outflow-quantity distributions for steady flow systems

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    A steady, two-dimensional flow system is used to demonstrate the application of location/arrival-time and location/outflow-quantity curves in determining the environmental consequences of groundwater contamination. The subsurface geologic and hydrologic evaluations needed to obtain the arrival results involve a sequence of four phases: system identification, new potential determination, flow systems kinematics, and contaminant transport analysis. Once these phases are completed, they are effectively summarized and easily used to evaluate environmental consequences through the arrival distributions