Historically defined autobiographical periods
DEFF Research Database (Denmark)
Brown, Norman R.; Hansen, Tia G. B.; Lee, Peter J.;
2012-01-01
The chapter reviews a research programme that has demonstrated the existence of historically defined autobiographical periods and identified the conditions that bring them about. Data from four samples of World War II-generation adults show that historically defined autobiographical periods endure...... over time and theoretical implications are discussed, notably by introducing a new approach to autobiographical memory, Transition Theory, which assumes that autobiographical memory is organized by transitional events that can be selfinitiated or externally imposed - historically defined...
Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)
2004-01-01
textabstractThis book considers periodic time series models for seasonal data, characterized by parameters that differ across the seasons, and focuses on their usefulness for out-of-sample forecasting. Providing an up-to-date survey of the recent developments in periodic time series, the book
38 CFR 17.31 - Duty periods defined.
2010-07-01
... Definitions and Active Duty § 17.31 Duty periods defined. Full-time duty as a member of the Women's Army Auxiliary Corps, Women's Reserve of the Navy and Marine Corps and Women's Reserve of the Coast Guard... Patient Rights...
Mammalian cycles: internally defined periods and interaction-driven amplitudes.
Ginzburg, L R; Krebs, C J
2015-01-01
The cause of mammalian cycles-the rise and fall of populations over a predictable period of time-has remained controversial since these patterns were first observed over a century ago. In spite of extensive work on observable mammalian cycles, the field has remained divided upon what the true cause is, with a majority of opinions attributing it to either predation or to intra-species mechanisms. Here we unite the eigenperiod hypothesis, which describes an internal, maternal effect-based mechanism to explain the cycles' periods with a recent generalization explaining the amplitude of snowshoe hare cycles in northwestern North America based on initial predator abundance. By explaining the period and the amplitude of the cycle with separate mechanisms, a unified and consistent view of the causation of cycles is reached. Based on our suggested theory, we forecast the next snowshoe hare cycle (predicted peak in 2016) to be of extraordinarily low amplitude.
Acquisition Cycle Time: Defining the Problem
2016-04-01
prescribe appetite suppression and fiscal discipline . Still others diagnose inept management and excessive bureaucracy, and prescribe streamlined...complex the system, the higher this bound. • Software development consists of completing known work and discovering new work. There are fundamental ... taxonomy of acquisition risk categories, with corresponding development timelines. In that report, a low-risk acquisition is defined to be one that
Mammalian cycles: internally defined periods and interaction-driven amplitudes
Directory of Open Access Journals (Sweden)
LR Ginzburg
2015-08-01
Full Text Available The cause of mammalian cycles—the rise and fall of populations over a predictable period of time—has remained controversial since these patterns were first observed over a century ago. In spite of extensive work on observable mammalian cycles, the field has remained divided upon what the true cause is, with a majority of opinions attributing it to either predation or to intra-species mechanisms. Here we unite the eigenperiod hypothesis, which describes an internal, maternal effect-based mechanism to explain the cycles’ periods with a recent generalization explaining the amplitude of snowshoe hare cycles in northwestern North America based on initial predator abundance. By explaining the period and the amplitude of the cycle with separate mechanisms, a unified and consistent view of the causation of cycles is reached. Based on our suggested theory, we forecast the next snowshoe hare cycle (predicted peak in 2016 to be of extraordinarily low amplitude.
Mammalian cycles: internally defined periods and interaction-driven amplitudes
Krebs, CJ
2015-01-01
The cause of mammalian cycles—the rise and fall of populations over a predictable period of time—has remained controversial since these patterns were first observed over a century ago. In spite of extensive work on observable mammalian cycles, the field has remained divided upon what the true cause is, with a majority of opinions attributing it to either predation or to intra-species mechanisms. Here we unite the eigenperiod hypothesis, which describes an internal, maternal effect-based mechanism to explain the cycles’ periods with a recent generalization explaining the amplitude of snowshoe hare cycles in northwestern North America based on initial predator abundance. By explaining the period and the amplitude of the cycle with separate mechanisms, a unified and consistent view of the causation of cycles is reached. Based on our suggested theory, we forecast the next snowshoe hare cycle (predicted peak in 2016) to be of extraordinarily low amplitude. PMID:26339557
Defining Leadership in a Changing Time.
Elwell, Sean M; Elikofer, Amanda N
2015-01-01
The purpose of this article is to discuss the difference between leadership and management. Leadership and management have been discussed for many years. Both are important to achieve success in health care, but what does that really mean? Strong leaders possess qualities that inspire others to follow them. This fosters team engagement, goal achievement, and ultimately drives outcomes. Managers plan, organize, and coordinate. It takes dedication, motivation, and passion to be more than a manager and be a good leader. There is not a single correct leadership style, but there are important characteristics that all leaders must demonstrate to get the desired results with the team. In a time when health care is rapidly changing, leadership is important at all levels of an organization.
Runoff response time of a loosely defined supraglacial microbasin
Directory of Open Access Journals (Sweden)
D. Scott Munro
2010-02-01
Full Text Available A micrometeorological experiment was conducted in the summer of 2008, at Peyto Glacier, during four meltwater production periods of 1, 3, 4 and 5 days duration, the last two days marked by late summer snow cover. The data include a breakdown of net radiation into its short- and long-wave components, as well as wind speed, temperature and humidity profile data for use in bulk transfer estimates of sensible heat and moisture transfer. In addition, a hydrological experiment was conducted, the data comprising sonic sounder measurements of ablation and stage level records of discharge from a supraglacial microbasin. As expected, the ratio of daily average runoff flow measurement to energy budget flow estimates is less than one on most days because of weathering crust development. Also, the conversion of stage level data into discharge from a supraglacial catchment presents challenges, notably defining the area of a loosely defined basin and specifying stage level on a downward moving surface. Nevertheless, it is clear that peak discharge lags peak meltwater energy input by periods of four to six hours. A suitably lagged flow estimate can be achieved by passing the flow through a simple storage reservoir, using delay times of 14.5, 15, 7.5 and 9 h for each respective measurement period. This suggests that a substantial part of the delay in runoff from a glacier basin is tied up in ice surface hydrological processes.
First passage times: Busy periods and waiting times
Institute of Scientific and Technical Information of China (English)
徐光煇; 袁学明
1995-01-01
General expressions of first passage times for denumerable Markov processes are discussed and computation problems for busy periods and waiting times for queues corresponding to Markov processes are studied. In particular, the simplified algorithms for busy periods and waiting times for queues corresponding to G//M/1 type and M/G/1 type Markov processes are derived and some numerical examples are presented.
Forecasting with periodic autoregressive time series models
Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)
1999-01-01
textabstractThis paper is concerned with forecasting univariate seasonal time series data using periodic autoregressive models. We show how one should account for unit roots and deterministic terms when generating out-of-sample forecasts. We illustrate the models for various quarterly UK consumption
Forecasting with periodic autoregressive time series models
Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)
1999-01-01
textabstractThis paper is concerned with forecasting univariate seasonal time series data using periodic autoregressive models. We show how one should account for unit roots and deterministic terms when generating out-of-sample forecasts. We illustrate the models for various quarterly UK consumption
Defining Social Class Across Time and Between Groups.
Cohen, Dov; Shin, Faith; Liu, Xi; Ondish, Peter; Kraus, Michael W
2017-08-01
We examined changes over four decades and between ethnic groups in how people define their social class. Changes included the increasing importance of income, decreasing importance of occupational prestige, and the demise of the "Victorian bargain," in which poor people who subscribed to conservative sexual and religious norms could think of themselves as middle class. The period also saw changes (among Whites) and continuity (among Black Americans) in subjective status perceptions. For Whites (and particularly poor Whites), their perceptions of enhanced social class were greatly reduced. Poor Whites now view their social class as slightly but significantly lower than their poor Black and Latino counterparts. For Black respondents, a caste-like understanding of social class persisted, as they continued to view their class standing as relatively independent of their achieved education, income, and occupation. Such achievement indicators, however, predicted Black respondents' self-esteem more than they predicted self-esteem for any other group.
MOFCOM Defined Major Tasks of Commercial Development during the 12th Five-Year Program Period
Institute of Scientific and Technical Information of China (English)
2012-01-01
According to CPC Central Committee＇s Proposal for Formulating the 12th Five-Year Program for National Economic and Social Development （2011- 2015） and the 12th Five-Year Program for National Economic and Social Development of the People＇s Republic of China, MQFCOM defined the guiding ideas, objectives, major tasks of China＇s commercial development during the 12th Five-Year Program period, after summarizing commercial achievements and experience in the 11th Five-Year Program period and analyzed the domestic and foreign environment during the 12th Five-Year Program.
Optimal periodic orbits of continuous time chaotic systems
Yang; Hunt; Ott
2000-08-01
In previous work [B. R. Hunt and E. Ott, Phys. Rev. Lett. 76, 2254 (1996); Phys. Rev. E 54, 328, (1996)], based on numerical experiments and analysis, it was conjectured that the optimal orbit selected from all possible orbits on a chaotic attractor is "typically" a periodic orbit of low period. By an optimal orbit we mean the orbit that yields the largest value of a time average of a given smooth "performance" function of the system state. Thus optimality is defined with respect to the given performance function. (The study of optimal orbits is of interest in at least three contexts: controlling chaos, embedding of low-dimensional attractors of high-dimensional dynamical systems in low-dimensional measurement spaces, and bubbling bifurcations of synchronized chaotic systems.) Here we extend this previous work. In particular, the previous work was for discrete time dynamical systems, and here we shall consider continuous time systems (flows). An essential difference for flows is that chaotic attractors can have embedded within them, not only unstable periodic orbits, but also unstable steady states, and we find that optimality can often occur on steady states. We also shed further light on the sense in which optimality is "typically" achieved at low period. In particular, we find that, as a system parameter is tuned to be closer to a crisis of the chaotic attractor, optimality may occur at higher period.
Analysis of the Mode of the Periodically Time-varying Vibration Systems
Institute of Scientific and Technical Information of China (English)
WANG Sheng-ze; REN Ji-ge
2007-01-01
By Liapunov reducibility theorem, the periodically time-varying vibration system can be transformed to a linear time-invariant system. Based on the dynamic characteristics of the linear time-invariant system, the mode of the periodically time-varying vibration system has been discussed. The paper defines the mode and analyzes its characteristics. It can be found that the mode of the periodically time-varying system is periodically time-varing but has such characteristics as orthogonality. Finally, a method is given to solve the mode. By solving the eigenvalues and the eigenvectors of the state transition matrix in one period, the periodically time-varying mode can be obtained.
Behaviour of time-dependent materials exposed to periodical loading
Directory of Open Access Journals (Sweden)
Zupancic B.
2010-06-01
Full Text Available Paper presents methodology for analyzing behaviour of time-dependent (viscoelastic materials when exposed to periodical (cyclic loading. Within each loading cycle time-dependent material undergoes a combination of the creep and retardation process. At certain conditions the retardation process between two loading cycles cannot be fully completed to a strain free state. Consequently, strain starts to accumulate, which leads to hardening of the material and ultimately to the failure of polymeric product. Critical frequency of the applied periodical loading depends on the material retardation time (location of mechanical spectrum, while the magnitude of accumulated strain on the strength of corresponding discrete spectrum lines. The shape of mechanical spectrum defines the intensity and the magnitude of accumulated strain. Thus, the mechanical spectrum of time-dependent material is the most important function for predicting durability of dynamically loaded polymeric products. In continuation we present mathematical methodology for predicting durability of periodically loaded polymeric components of drive belt. Methodology includes numerical calculations of accumulated strain as a function of the number of loading cycles and function of loading angular velocity. Based on these calculations we can determine the critical angular velocity area of periodical loading where the strain accumulation is the most intensive.
Defining the rest interval associated with the main sleep period in actigraph scoring.
Chow, Chin Moi; Wong, Shi Ngar; Shin, Mirim; Maddox, Rebecca G; Feilds, Kristy-Lee; Paxton, Karen; Hawke, Catherine; Hazell, Philip; Steinbeck, Katharine
2016-01-01
Actigraphy is increasingly used for sleep monitoring. However, there is a lack of standardized methodology for data processing and analysis, which often makes between study comparisons difficult, if not impossible, and thus open to flawed interpretation. This study evaluated a manual method for detection of the rest interval in actigraph data collected with Actiwatch 2. The rest interval (time in bed), defined as the bedtime and rise time and set by proprietary software, is an essential requirement for the estimation of sleep indices. This study manually and systematically detected the rest interval of 187 nights of recording from seven healthy males and three females, aged 13.5±0.7 (mean ± standard deviation) years. Data were analyzed for agreement between software default algorithm and manual scoring. Inter-rater reliability in manual scoring was also tested between two scorers. Data showed consistency between default settings and manual scorers for bedtime and rise time, but only moderate agreement for the rest interval duration and poor agreement for activity level at bedtime and rise time. Manual detection of rest intervals between scorers showed a high degree of agreement for all parameters (intraclass correlations range 0.864 to 0.995). The findings demonstrate that the default algorithm on occasions was unable to detect rest intervals or set the exact interval. Participant issues and inter-scorer issues also made difficult the detection of rest intervals. These findings have led to a manual detection protocol to define bedtime and rise time, supplemented with an event diary.
Energy Technology Data Exchange (ETDEWEB)
Starkov, Konstantin E., E-mail: kstarkov@ipn.mx
2015-07-03
In this paper we study invariant domains with unbounded dynamics for one cosmological Hamiltonian system which is formed by the conformally coupled field; this system was introduced by Maciejewski et al. (2007). We find a few groups of conditions imposed on parameters of this system for which all trajectories are unbounded in both of time directions. Further, we present a few groups of other conditions imposed on system parameters under which we localize the invariant domain with unbounded dynamics; this domain is defined with help of bounds for values of the Hamiltonian level surface parameter. We describe one group of conditions when our system possesses two periodic orbits found explicitly. In some of rest cases we get localization bounds for compact invariant sets. - Highlights: • Equations for periodic orbits are got for many level sets. • Domains with unbounded dynamics are localized. • Localizations for compact invariant sets are obtained.
Directory of Open Access Journals (Sweden)
Yongkun Li
2011-01-01
Full Text Available Firstly, we propose a concept of uniformly almost periodic functions on almost periodic time scales and investigate some basic properties of them. When time scale T=ℝ or ℤ, our definition of the uniformly almost periodic functions is equivalent to the classical definitions of uniformly almost periodic functions and the uniformly almost periodic sequences, respectively. Then, based on these, we study the existence and uniqueness of almost periodic solutions and derive some fundamental conditions of admitting an exponential dichotomy to linear dynamic equations. Finally, as an application of our results, we study the existence of almost periodic solutions for an almost periodic nonlinear dynamic equations on time scales.
On periodic orbits in discrete-time cascade systems
Directory of Open Access Journals (Sweden)
Huimin Li
2006-01-01
Full Text Available We present some results on existence, minimum period, number of periodic orbits, and stability of periodic orbits in discrete-time cascade systems. Some examples are presented to illustrate these results.
Defining the rest interval associated with the main sleep period in actigraph scoring
Directory of Open Access Journals (Sweden)
Chow CM
2016-11-01
Full Text Available Chin Moi Chow,1 Shi Ngar Wong,1 Mirim Shin,1 Rebecca G Maddox,2 Kristy-Lee Feilds,3 Karen Paxton,4 Catherine Hawke,4 Philip Hazell,3 Katharine Steinbeck5 1Discipline of Exercise and Sport Science, Faculty of Health Sciences, 2Sydney Medical School, 3Discipline of Psychiatry, 4School of Rural Health, 5Discipline of Paediatrics and Child Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia Abstract: Actigraphy is increasingly used for sleep monitoring. However, there is a lack of standardized methodology for data processing and analysis, which often makes between study comparisons difficult, if not impossible, and thus open to flawed interpretation. This study evaluated a manual method for detection of the rest interval in actigraph data collected with Actiwatch 2. The rest interval (time in bed, defined as the bedtime and rise time and set by proprietary software, is an essential requirement for the estimation of sleep indices. This study manually and systematically detected the rest interval of 187 nights of recording from seven healthy males and three females, aged 13.5±0.7 (mean ± standard deviation years. Data were analyzed for agreement between software default algorithm and manual scoring. Inter-rater reliability in manual scoring was also tested between two scorers. Data showed consistency between default settings and manual scorers for bedtime and rise time, but only moderate agreement for the rest interval duration and poor agreement for activity level at bedtime and rise time. Manual detection of rest intervals between scorers showed a high degree of agreement for all parameters (intraclass correlations range 0.864 to 0.995. The findings demonstrate that the default algorithm on occasions was unable to detect rest intervals or set the exact interval. Participant issues and inter-scorer issues also made difficult the detection of rest intervals. These findings have led to a manual detection protocol to define
Yuan, Rong
2007-06-01
In this paper, we study almost periodic logistic delay differential equations. The existence and module of almost periodic solutions are investigated. In particular, we extend some results of Seifert in [G. Seifert, Almost periodic solutions of certain differential equations with piecewise constant delays and almost periodic time dependence, J. Differential Equations 164 (2000) 451-458].
Defining solar park location using shadow over time detection method
Martynov, Ivan; Kauranne, Tuomo
2016-06-01
There is nowadays a high demand for research on using renewable sources of energy including solar energy. The availability of stable and efficient solar energy is of paramount importance. Therefore, it is vital to install solar panels in locations which are most of the time not in shadow. To illustrate this idea we have developed a shadow identification method for digital elevation models (DEMs) using the computational means of MATLAB whose environment and tools allow fast and easy image processing. As a source of DEMs we use the Shuttle Radar Topography Mission (SRTM) database since it covers most of the terrain of our planet.
Defining the timing of respiratory syncytial virus (RSV outbreaks: an epidemiological study
Directory of Open Access Journals (Sweden)
Enders Martin
2005-03-01
Full Text Available Abstract Background Seasonal RSV infections occur every year and affect particularly children under six months of age. Passive immunoprophylaxis with monoclonal antibody Palivizumab is recommended in the period with high risk of RSV infection. This study aims to define the period for the southern part of Germany (Stuttgart area. Methods Epidemiological analysis of the RSV situation in southern Germany from 1996 to 2004 and comparison of results with literature was made. The respiratory tract specimens were sent in for the detection of RSV mainly by paediatric clinics. Detection of RSV was carried out mainly by real-time RT-PCR or by ELISA "Pathfinder". RSV outbreaks were depicted as an absolute number and as a percentage of RSV diagnoses in a month. Onsets, offsets, peaks, duration and severity of RSV seasons were defined and analysed. Results An early season with strong RSV activity (early-high phase was followed by a weaker late season (late-low phase in a regular biennial rhythm. However, onsets, offsets and durations of outbreaks varied significantly from year to year. RSV epidemics in southern Germany were found to oscillate in an antiphase with RSV epidemics in Finland and Sweden. Conclusion The long-term regular biennial rhythm allows predicting whether the next outbreak will be late or early and whether RSV activity will be strong or weak. Not foreseeable, however, is the precise time of increase and decrease of RSV activity. Moreover, the regular seasonal pattern may be disrupted by irregular outbreaks. Thus, activity of RSV has to be monitored every year to define the period with high risk of infection.
Different Ultimate Factors Define Timing of Breeding in Two Related Species.
Pakanen, Veli-Matti; Orell, Markku; Vatka, Emma; Rytkönen, Seppo; Broggi, Juli
2016-01-01
Correct reproductive timing is crucial for fitness. Breeding phenology even in similar species can differ due to different selective pressures on the timing of reproduction. These selection pressures define species' responses to warming springs. The temporal match-mismatch hypothesis suggests that timing of breeding in animals is selected to match with food availability (synchrony). Alternatively, time-dependent breeding success (the date hypothesis) can result from other seasonally deteriorating ecological conditions such as intra- or interspecific competition or predation. We studied the effects of two ultimate factors on the timing of breeding, synchrony and other time-dependent factors (time-dependence), in sympatric populations of two related forest-dwelling passerine species, the great tit (Parus major) and the willow tit (Poecile montanus) by modelling recruitment with long-term capture-recapture data. We hypothesized that these two factors have different relevance for fitness in these species. We found that local recruitment in both species showed quadratic relationships with both time-dependence and synchrony. However, the importance of these factors was markedly different between the studied species. Caterpillar food played a predominant role in predicting the timing of breeding of the great tit. In contrast, for the willow tit time-dependence modelled as timing in relation to conspecifics was more important for local recruitment than synchrony. High caterpillar biomass experienced during the pre- and post-fledging periods increased local recruitment of both species. These contrasting results confirm that these species experience different selective pressures upon the timing of breeding, and hence responses to climate change may differ. Detailed information about life-history strategies is required to understand the effects of climate change, even in closely related taxa. The temporal match-mismatch hypothesis should be extended to consider subsequent
Mining approximate periodic pattern in hydrological time series
Zhu, Y. L.; Li, S. J.; Bao, N. N.; Wan, D. S.
2012-04-01
There is a lot of information about the hidden laws of nature evolution and the influences of human beings activities on the earth surface in long sequence of hydrological time series. Data mining technology can help find those hidden laws, such as flood frequency and abrupt change, which is useful for the decision support of hydrological prediction and flood control scheduling. The periodic nature of hydrological time series is important for trend forecasting of drought and flood and hydraulic engineering planning. In Hydrology, the full period analysis of hydrological time series has attracted a lot of attention, such as the discrete periodogram, simple partial wave method, Fourier analysis method, and maximum entropy spectral analysis method and wavelet analysis. In fact, the hydrological process is influenced both by deterministic factors and stochastic ones. For example, the tidal level is also affected by moon circling the Earth, in addition to the Earth revolution and its rotation. Hence, there is some kind of approximate period hidden in the hydrological time series, sometimes which is also called the cryptic period. Recently, partial period mining originated from the data mining domain can be a remedy for the traditional period analysis methods in hydrology, which has a loose request of the data integrity and continuity. They can find some partial period in the time series. This paper is focused on the partial period mining in the hydrological time series. Based on asynchronous periodic pattern and partial period mining with suffix tree, this paper proposes to mine multi-event asynchronous periodic pattern based on modified suffix tree representation and traversal, and invent a dynamic candidate period intervals adjusting method, which can avoids period omissions or waste of time and space. The experimental results on synthetic data and real water level data of the Yangtze River at Nanjing station indicate that this algorithm can discover hydrological
2010-04-01
... 19 Customs Duties 2 2010-04-01 2010-04-01 false Time period. 158.21a Section 158.21a Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... While in Customs Custody § 158.21a Time period. An abatement or refund of duties shall be made in the...
Band structure engineering of graphene by a local gate defined periodic potential
Forsythe, Carlos; Maher, Patrick; Scarabelli, Diego; Dean, Cory; Kim, Philip
Recent improvements in 2-dimensional (2D) material layering have resulted in enhanced device quality and created pathways for new device architectures. We fabricate periodic arrays from a patterned local back gate and a uniform top gate on hBN encapsulated graphene channels. The symmetry and lattice size of the periodic potential can be determined by state-of-art electron beam lithography and etching, achieving a lattice constant of 35 nm. The strength of the electric potential modulation can be controlled through applied voltage on the patterned gate. We observe signatures of superlattice modulation near the main Dirac peak in the density dependent resistance measurement at zero magnetic field. Current studies focus on the exploration of Hofstadter fractal band structures under magnetic fields. Our nano-patterned engineered superlattices on graphene hold great promise for wider applications.
Satisfactory control of discrete-time linear periodic systems
Institute of Scientific and Technical Information of China (English)
Shiqian LIU; Jihong ZHU; JinChun HU
2007-01-01
In this paper satisfactory control for discrete-time linear periodic systems is studied.Based on a suitable time-invariant state sampled reformulation,periodic state feedback controller has been designed such that desired requirements of steady state covariance,H-infinity rejection bound and regional pole assignment for the periodic system are met simultaneously.By using satisfactory control theory,the problem of satisfactory periodic controller can be transformed into a linear programming problem subject to a set of linear matrix inequalities(LMIs).and a feasible designing approach is presented via LMI technique.Numeric example validates the obtained conclusion.
Bendahhou, Saïd; Cummins, Theodore R.; Hahn, Angelika F.; Langlois, Sylvie; Waxman, Stephen G.; Ptácek, Louis J.
2000-01-01
Hyperkalemic periodic paralysis (HyperKPP) is an autosomal dominant skeletal muscle disorder caused by single mutations in the SCN4A gene, encoding the human skeletal muscle voltage-gated Na+ channel. We have now identified one allele with two novel mutations occurring simultaneously in the SCN4A gene. These mutations are found in two distinct families that had symptoms of periodic paralysis and malignant hyperthermia susceptibility. The two nucleotide transitions predict phenylalanine 1490→leucine and methionine 1493→isoleucine changes located in the transmembrane segment S5 in the fourth repeat of the α-subunit Na+ channel. Surprisingly, this mutation did not affect fast inactivation parameters. The only defect produced by the double mutant (F1490L-M1493I, expressed in human embryonic kidney 293 cells) is an enhancement of slow inactivation, a unique behavior not seen in the 24 other disease-causing mutations. The behavior observed in these mutant channels demonstrates that manifestation of HyperKPP does not necessarily require disruption of slow inactivation. Our findings may also shed light on the molecular determinants and mechanism of Na+ channel slow inactivation and help clarify the relationship between Na+ channel defects and the long-term paralytic attacks experienced by patients with HyperKPP. PMID:10930446
Periodicity Estimation in Mechanical Acoustic Time-Series Data
Directory of Open Access Journals (Sweden)
Zhu Yongbo
2015-01-01
Full Text Available Periodicity estimation in mechanical acoustic time-series data is a well-established problem in data mining as it can be applicable in variety of disciplines either for anomaly detection or for prediction purposes in industry. In this paper, we develop a new approach for capturing and characterizing periodic patterns in time-series data by virtue of the dynamic time warping (DTW. We have conducted extensive experiments to evaluate the proposed approach with synthetic data and our collected data in practice. Experimental results demonstrated its effectiveness and robustness on periodicity detection in highly noised data.
A time-periodic reaction-diffusion epidemic model with infection period
Zhang, Liang; Wang, Zhi-Cheng
2016-10-01
In this paper, we propose a time-periodic and diffusive SIR epidemic model with constant infection period. By introducing the basic reproduction number R_0 via a next generation operator for this model, we show that the disease goes extinction if R_0 1.
Energy Technology Data Exchange (ETDEWEB)
Sun Wen [School of Mathematics and Statistics, Wuhan University, Wuhan 430072 (China); Chen Shihua [School of Mathematics and Statistics, Wuhan University, Wuhan 430072 (China)]. E-mail: shcheng@whu.edu.cn; Hong Zhiming [School of Mathematics and Statistics, Wuhan University, Wuhan 430072 (China); Wang Changping [Department of Mathematics and Statistics, Dalhousie University, Halifax, NS, B3H 3J5 (Canada)
2007-08-15
A two-species periodic competition Lotka-Volterra system with time delay and diffusion is investigated. Some sufficient conditions of the existence of positive periodic solution are established for the system by using the continuation theorem of coincidence degree theory.
Periodic flows to chaos in time-delay systems
Luo, Albert C J
2017-01-01
This book for the first time examines periodic motions to chaos in time-delay systems, which exist extensively in engineering. For a long time, the stability of time-delay systems at equilibrium has been of great interest from the Lyapunov theory-based methods, where one cannot achieve the ideal results. Thus, time-delay discretization in time-delay systems was used for the stability of these systems. In this volume, Dr. Luo presents an accurate method based on the finite Fourier series to determine periodic motions in nonlinear time-delay systems. The stability and bifurcation of periodic motions are determined by the time-delayed system of coefficients in the Fourier series and the method for nonlinear time-delay systems is equivalent to the Laplace transformation method for linear time-delay systems. Facilitates discovery of analytical solutions of nonlinear time-delay systems; Illustrates bifurcation trees of periodic motions to chaos; Helps readers identify motion complexity and singularity; Explains pro...
Forecasting Daily Time Series using Periodic Unobserved Components Time Series Models
Koopman, Siem Jan; Ooms, Marius
2004-01-01
We explore a periodic analysis in the context of unobserved components time series models that decompose time series into components of interest such as trend and seasonal. Periodic time series models allow dynamic characteristics to depend on the period of the year, month, week or day. In the stand
Forecasting Daily Time Series using Periodic Unobserved Components Time Series Models
Koopman, Siem Jan; Ooms, Marius
2004-01-01
We explore a periodic analysis in the context of unobserved components time series models that decompose time series into components of interest such as trend and seasonal. Periodic time series models allow dynamic characteristics to depend on the period of the year, month, week or day. In the
User-Defined Clocks in the Real-Time Specification for Java
DEFF Research Database (Denmark)
Wellings, Andy; Schoeberl, Martin
2011-01-01
This paper analyses the new user-defined clock model that is to be supported in Version 1.1 of the Real-Time Specification for Java (RTSJ). The model is a compromise between the current position, where there is no support for user-defined clocks, and a fully integrated model. The paper investigat...
Return times at periodic points in random dynamics
Haydn, Nicolai; Todd, Mike
2017-01-01
We prove a quenched limiting law for random measures on subshifts at periodic points. We consider a family of measures {≤ft\\{{{μω}\\right\\}}ω \\in Ω } , where the ‘driving space’ Ω is equipped with a probability measure which is invariant under a transformation θ. We assume that the fibred measures {μω} satisfy a generalised invariance property and are ψ-mixing. We then show that for almost every ω the return times to cylinders A n at periodic points are in the limit compound Poisson distributed for a parameter ϑ which is given by the escape rate at the periodic point.
Extracting unstable periodic orbits from chaotic time series data
Energy Technology Data Exchange (ETDEWEB)
So, P.; Schiff, S.; Gluckman, B.J., [Center for Neuroscience, Childrens Research Institute, Childrens National Medical Center and the George Washington University, NW, Washington, D.C. 20010 (United States); So, P.; Ott, E.; Grebogi, C., [Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 (United States); Sauer, T., [Department of Mathematics, The George Mason University, Fairfax, Virginia 22030 (United States); Gluckman, B.J., [Naval Surface Warfare Center, Carderock Division, Bethesda, Maryland 20054-5000 (United States)
1997-05-01
A general nonlinear method to extract unstable periodic orbits from chaotic time series is proposed. By utilizing the estimated local dynamics along a trajectory, we devise a transformation of the time series data such that the transformed data are concentrated on the periodic orbits. Thus, one can extract unstable periodic orbits from a chaotic time series by simply looking for peaks in a finite grid approximation of the distribution function of the transformed data. Our method is demonstrated using data from both numerical and experimental examples, including neuronal ensemble data from mammalian brain slices. The statistical significance of the results in the presence of noise is assessed using surrogate data. {copyright} {ital 1997} {ital The American Physical Society}
Infrared Variability and Time Lags for Periodic Quasars
Jun, Hyunsung David; Stern, Daniel; Graham, Matthew J.; Djorgovski, Stanislav G.; Mainzer, Amy; Cutri, Roc M.; Drake, Andrew J.; Mahabal, Ashish A.
2017-01-01
The optical light curve of the quasar PG 1302-102 at z=0.278 shows a 5.2 year periodic signal, detectable over a period of 20 years. The most plausible mechanisms involve a binary supermassive black hole system with a sub-pc separation, where they will likely merge within ~10^5 years due to gravitational wave emission alone. Here, we report the infrared time lags for PG 1302-102 from WISE and Akari missions. We confirm that the periodic behavior reported in the optical light curve is reproduced at infrared, with best-fit 3.4 and 4.6 micron time lags of (2219 ± 153, 2408 ± 148) days for a near face-on orientation of the torus, or (4103 ± 153, 4292 ± 148) days for an inclined system with relativistic Doppler boosting in effect. The periodicity in the infrared light curves and the time lag to the optical support that a source within the accretion disk is responsible for the optical variability of PG 1302-102, echoed at the farther out dusty regions ~1.1-1.3 pc away. We briefly mention ongoing works to constrain the infrared variability and time lags for all the identified periodic quasars, and to relate the quantities to physical origins.
False periodicities in quasar time-domain surveys
Vaughan, S; Markowitz, A G; Huppenkothen, D; Middleton, M J; Alston, W N; Scargle, J D; Farr, W M
2016-01-01
There have recently been several reports of apparently periodic variations in the light curves of quasars, e.g. PG 1302-102 by Graham et al. (2015a). Any quasar showing periodic oscillations in brightness would be a strong candidate to be a close binary supermassive black hole and, in turn, a candidate for gravitational wave studies. However, normal quasars -- powered by accretion onto a single, supermassive black hole -- usually show stochastic variability over a wide range of timescales. It is therefore important to carefully assess the methods for identifying periodic candidates from among a population dominated by stochastic variability. Using a Bayesian analysis of the light curve of PG 1302-102, we find that a simple stochastic process is preferred over a sinusoidal variations. We then discuss some of the problems one encounters when searching for rare, strictly periodic signals among a large number of irregularly sampled, stochastic time series, and use simulations of quasar light curves to illustrate ...
Variable time-period optical switching: a novel OBS implementation
Institute of Scientific and Technical Information of China (English)
Jinsong Zhang(张劲松); Mingcui Cao(曹明翠); Fengguang Luo(罗风光); Tao Chen(陈涛)
2003-01-01
In this paper, we proposed a novel optical switching method based on optical burst switching (OBS), we call it variable time-period optical switching (VTPOS). It can both support circuit services and other immerged packet services. It has better usability of bandwidth, shorter offset and latency time than others of unidirectional transport signaling mechanisms for OBS. It supports deflection switching for improve blocking performance without the need of schedule buffer. It introduces a time pointer and phase indicator that made synchronous more precisely and requires less guard time, it also classifies the different services classes with a relative QoS model.
Pseudo analytical solution to time periodic stiffness systems
Institute of Scientific and Technical Information of China (English)
Wang Yan-Zhong; Zhou Yuan-Zi
2011-01-01
An analytical form of state transition matrix for a system of equations with time periodic stiffness is derived in order to solve the free response and also allow for the determination of system stability and bifurcation. A pseudoclosed form complete solution for parametrically excited systems subjected to inhomogeneous generalized forcing is developed, based on the Fourier expansion of periodic matrices and the substitution of matrix exponential terms via Lagrange-Sylvester theorem. A Mathieu type of equation with large amplitude is presented to demonstrate the method of formulating state transition matrix and Floquet multipliers. A two-degree-of-freedom system with irregular time periodic stiffness characterized by spiral bevel gear mesh vibration is presented to find forced response in stability and instability. The obtained results are presented and discussed.
Analysis of time-domain scattering by periodic structures
Gao, Yixian; Li, Peijun
2016-11-01
This paper is devoted to the mathematical analysis of a time-domain electromagnetic scattering by periodic structures which are known as diffraction gratings. The scattering problem is reduced equivalently into an initial-boundary value problem in a bounded domain by using an exact transparent boundary condition. The well-posedness and stability of the solution are established for the reduced problem. Moreover, a priori energy estimates are obtained with minimum regularity requirement for the data and explicit dependence on the time.
Physical Activity in High School during "Free-Time" Periods
Silva, Pedro; Sousa, Michael; Sá, Carla; Ribeiro, José; Mota, Jorge
2015-01-01
The purpose of this study was to examine youth physical activity (PA) in free-time periods during high school days and their contribution to total PA. Differences in terms of sex, age, body mass index and school level were assessed in a sample of Portuguese adolescents. Participants totalled 213 (135 girls), aged 14.6 ± 1.7, from two different…
Physical characters of KLS time-periodic universe
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
In this paper we consider the physical characters of the new time-periodic solution of the vacuum Einstein’s field equations which was constructed by Kong, Liu and Shen. By the analysis of the Penrose diagram associated with this solution, we find that this solution is very different from the other solutions.
Entanglement properties of the time-periodic Kitaev chain
Yates, Daniel J.; Mitra, Aditi
2017-09-01
The entanglement properties of the time-periodic Kitaev chain with nearest-neighbor and next-nearest-neighbor hopping is studied. The cases of the exact eigenstate of the time-periodic Hamiltonian, referred to as the Floquet ground state (FGS), as well as a physical state obtained from time evolving an initial state unitarily under the influence of the time-periodic drive are explored. Topological phases are characterized by different numbers of Majorana zero (Z0) and π (Zπ) modes, where the zero modes are present even in the absence of the drive, while the π modes arise due to resonant driving. The entanglement spectrum (ES) of the FGS as well as the physical state show topological Majorana modes whose number is different from that of the quasienergy spectrum. The number of Majorana edge modes in the ES of the FGS vary in time from | Z0-Zπ| to Z0+Zπ within one drive cycle, with the maximal Z0+Zπ modes appearing at a special time-reversal-symmetric point of the cycle. For the physical state, on the other hand, only the modes inherited from the initial wave function, namely the Z0 modes, appear in the ES. The Zπ modes are absent in the physical state as they merge with the bulk excitations that are simultaneously created due to resonant driving. The topological properties of the Majorana zero and π modes in the ES are also explained by mapping the parent wave function to a Bloch sphere.
Time-periodic solutions of the Benjamin-Ono equation
Energy Technology Data Exchange (ETDEWEB)
Ambrose , D.M.; Wilkening, Jon
2008-04-01
We present a spectrally accurate numerical method for finding non-trivial time-periodic solutions of non-linear partial differential equations. The method is based on minimizing a functional (of the initial condition and the period) that is positive unless the solution is periodic, in which case it is zero. We solve an adjoint PDE to compute the gradient of this functional with respect to the initial condition. We include additional terms in the functional to specify the free parameters, which, in the case of the Benjamin-Ono equation, are the mean, a spatial phase, a temporal phase and the real part of one of the Fourier modes at t = 0. We use our method to study global paths of non-trivial time-periodic solutions connecting stationary and traveling waves of the Benjamin-Ono equation. As a starting guess for each path, we compute periodic solutions of the linearized problem by solving an infinite dimensional eigenvalue problem in closed form. We then use our numerical method to continue these solutions beyond the realm of linear theory until another traveling wave is reached (or until the solution blows up). By experimentation with data fitting, we identify the analytical form of the solutions on the path connecting the one-hump stationary solution to the two-hump traveling wave. We then derive exact formulas for these solutions by explicitly solving the system of ODE's governing the evolution of solitons using the ansatz suggested by the numerical simulations.
A method for obtaining time-periodic Lp estimates
Kyed, Mads; Sauer, Jonas
2017-01-01
We introduce a method for showing a prioriLp estimates for time-periodic, linear, partial differential equations set in a variety of domains such as the whole space, the half space and bounded domains. The method is generic and can be applied to a wide range of problems. We demonstrate it on the heat equation. The main idea is to replace the time axis with a torus in order to reformulate the problem on a locally compact abelian group and to employ Fourier analysis on this group. As a by-product, maximal Lp regularity for the corresponding initial-value problem follows without the notion of R-boundedness. Moreover, we introduce the concept of a time-periodic fundamental solution.
Periodic, Quasi-periodic and Chaotic Dynamics in Simple Gene Elements with Time Delays.
Suzuki, Yoko; Lu, Mingyang; Ben-Jacob, Eshel; Onuchic, José N
2016-02-15
Regulatory gene circuit motifs play crucial roles in performing and maintaining vital cellular functions. Frequently, theoretical studies of gene circuits focus on steady-state behaviors and do not include time delays. In this study, the inclusion of time delays is shown to entirely change the time-dependent dynamics for even the simplest possible circuits with one and two gene elements with self and cross regulations. These elements can give rise to rich behaviors including periodic, quasi-periodic, weak chaotic, strong chaotic and intermittent dynamics. We introduce a special power-spectrum-based method to characterize and discriminate these dynamical modes quantitatively. Our simulation results suggest that, while a single negative feedback loop of either one- or two-gene element can only have periodic dynamics, the elements with two positive/negative feedback loops are the minimalist elements to have chaotic dynamics. These elements typically have one negative feedback loop that generates oscillations, and another unit that allows frequent switches among multiple steady states or between oscillatory and non-oscillatory dynamics. Possible dynamical features of several simple one- and two-gene elements are presented in details. Discussion is presented for possible roles of the chaotic behavior in the robustness of cellular functions and diseases, for example, in the context of cancer.
Periodic, Quasi-periodic and Chaotic Dynamics in Simple Gene Elements with Time Delays
Suzuki, Yoko; Lu, Mingyang; Ben-Jacob, Eshel; Onuchic, José N.
2016-02-01
Regulatory gene circuit motifs play crucial roles in performing and maintaining vital cellular functions. Frequently, theoretical studies of gene circuits focus on steady-state behaviors and do not include time delays. In this study, the inclusion of time delays is shown to entirely change the time-dependent dynamics for even the simplest possible circuits with one and two gene elements with self and cross regulations. These elements can give rise to rich behaviors including periodic, quasi-periodic, weak chaotic, strong chaotic and intermittent dynamics. We introduce a special power-spectrum-based method to characterize and discriminate these dynamical modes quantitatively. Our simulation results suggest that, while a single negative feedback loop of either one- or two-gene element can only have periodic dynamics, the elements with two positive/negative feedback loops are the minimalist elements to have chaotic dynamics. These elements typically have one negative feedback loop that generates oscillations, and another unit that allows frequent switches among multiple steady states or between oscillatory and non-oscillatory dynamics. Possible dynamical features of several simple one- and two-gene elements are presented in details. Discussion is presented for possible roles of the chaotic behavior in the robustness of cellular functions and diseases, for example, in the context of cancer.
Time-Periodic Einstein--Klein--Gordon Bifurcations of Kerr
Chodosh, Otis
2015-01-01
We construct one-parameter families of solutions to the Einstein--Klein--Gordon equations bifurcating off the Kerr solution such that the underlying family of spacetimes are each an asymptotically flat, stationary, axisymmetric, black hole spacetime, and such that the corresponding scalar fields are non-zero and time-periodic. An immediate corollary is that for these Klein--Gordon masses, the Kerr family is not asymptotically stable as a solution to the Einstein--Klein--Gordon equations.
Time-periodic N\\'eel wall motions
Huber, Alexander
2010-01-01
In thin ferromagnetic films, the predominance of the magnetic shape anisotropy leads to in-plane magnetizations. The simplest domain wall in this geometry is the one-dimensional Neel wall that connects two magnetizations of opposite sign by a planar 180 degree rotation. In this paper, we perturb the static Neel wall profile in order to construct time-periodic Neel wall motions governed by to the Landau-Lifshitz-Gilbert equation. Our construction works within a certain parameter regime and requires the restriction to external magnetic fields with small amplitudes and suitable time averages.
Krylov-subspace acceleration of time periodic waveform relaxation
Energy Technology Data Exchange (ETDEWEB)
Lumsdaine, A. [Univ. of Notre Dame, IN (United States)
1994-12-31
In this paper the author uses Krylov-subspace techniques to accelerate the convergence of waveform relaxation applied to solving systems of first order time periodic ordinary differential equations. He considers the problem in the frequency domain and presents frequency dependent waveform GMRES (FDWGMRES), a member of a new class of frequency dependent Krylov-subspace techniques. FDWGMRES exhibits many desirable properties, including finite termination independent of the number of timesteps and, for certain problems, a convergence rate which is bounded from above by the convergence rate of GMRES applied to the static matrix problem corresponding to the linear time-invariant ODE.
A restricted period for formation of outer subventricular zone defined by Cdh1 and Trnp1 levels.
Martínez-Martínez, Maria Ángeles; De Juan Romero, Camino; Fernández, Virginia; Cárdenas, Adrián; Götz, Magdalena; Borrell, Víctor
2016-06-06
The outer subventricular zone (OSVZ) is a germinal layer playing key roles in the development of the neocortex, with particular relevance in gyrencephalic species such as human and ferret, where it contains abundant basal radial glia cells (bRGCs) that promote cortical expansion. Here we identify a brief period in ferret embryonic development when apical RGCs generate a burst of bRGCs that become founders of the OSVZ. After this period, bRGCs in the OSVZ proliferate and self-renew exclusively locally, thereby forming a self-sustained lineage independent from the other germinal layers. The time window for the brief period of OSVZ bRGC production is delineated by the coincident downregulation of Cdh1 and Trnp1, and their upregulation reduces bRGC production and prevents OSVZ seeding. This mechanism in cortical development may have key relevance in brain evolution and disease.
Periodicity and stability for variable-time impulsive neural networks.
Li, Hongfei; Li, Chuandong; Huang, Tingwen
2017-10-01
The paper considers a general neural networks model with variable-time impulses. It is shown that each solution of the system intersects with every discontinuous surface exactly once via several new well-proposed assumptions. Moreover, based on the comparison principle, this paper shows that neural networks with variable-time impulse can be reduced to the corresponding neural network with fixed-time impulses under well-selected conditions. Meanwhile, the fixed-time impulsive systems can be regarded as the comparison system of the variable-time impulsive neural networks. Furthermore, a series of sufficient criteria are derived to ensure the existence and global exponential stability of periodic solution of variable-time impulsive neural networks, and to illustrate the same stability properties between variable-time impulsive neural networks and the fixed-time ones. The new criteria are established by applying Schaefer's fixed point theorem combined with the use of inequality technique. Finally, a numerical example is presented to show the effectiveness of the proposed results. Copyright © 2017 Elsevier Ltd. All rights reserved.
Sleep Period Time Estimation Based on Electrodermal Activity.
Hwang, Su Hwan; Seo, Sangwon; Yoon, Hee Nam; Jung, Da Woon; Baek, Hyun Jae; Cho, Jaegeol; Choi, Jae Won; Lee, Yu Jin; Jeong, Do-Un; Park, Kwang Suk
2017-01-01
We proposed and tested a method to estimate sleep period time (SPT) using electrodermal activity (EDA) signals. Eight healthy subjects and six obstructive sleep apnea patients participated in the experiments. Each subject's EDA signals were measured at the middle and ring fingers of the dominant hand during polysomnography (PSG). For nine of the 17 participants, wrist actigraphy was also measured for a quantitative comparison of EDA- and actigraphy-based methods. Based on the training data, we observed that sleep onset was accompanied by a gradual reduction of amplitude of the EDA signals, whereas sleep offset was accompanied by a rapid increase in amplitude of EDA signals. We developed a method based on these EDA fluctuations during sleep-wake transitions, and applied it to a test dataset. The performance of the method was assessed by comparing its results with those from a physician's sleep stage scores. The mean absolute errors in the obtained values for sleep onset, offset, and period time between the proposed method, and the results of the PSG were 4.1, 3.0, and 6.1 min, respectively. Furthermore, there were no significant differences in the corresponding values between the methods. We compared these results with those obtained by applying actigraphic methods, and found that our algorithm outperformed these in terms of each estimated parameter of interest in SPT estimation. Long awakening periods were also detected based on sympathetic responses reflected in the EDA signals. The proposed method can be applied to a daily sleep monitoring system.
Minimal model for short-time diffusion in periodic potentials.
Emary, Clive; Gernert, Robert; Klapp, Sabine H L
2012-12-01
We investigate the dynamics of a single, overdamped colloidal particle, which is driven by a constant force through a one-dimensional periodic potential. We focus on systems with large barrier heights where the lowest-order cumulants of the density field, that is, average position and the mean-squared displacement, show nontrivial (nondiffusive) short-time behavior characterized by the appearance of plateaus. We demonstrate that this "cage-like" dynamics can be well described by a discretized master equation model involving two states (related to two positions) within each potential valley. Nontrivial predictions of our approach include analytic expressions for the plateau heights and an estimate of the "de-caging time" obtained from the study of deviations from Gaussian behavior. The simplicity of our approach means that it offers a minimal model to describe the short-time behavior of systems with hindered dynamics.
Djallel Dilmi, Mohamed; Mallet, Cécile; Barthes, Laurent; Chazottes, Aymeric
2017-04-01
The Precipitations are due to complex meteorological phenomenon and can be described as intermittent process. Theirs spatial and temporal variability is significant and covers large scales. These precipitation properties induce a very strong constraint on the measurement, which must be as continuous as possible, both in time and in space. . In particular, studies of climate change need high-resolution rainfall with resolutions much higher than 1 hour to obtain statistics of extrem rainfall and wet and dry spell duration. For all these reasons, several instruments were used for the observation of precipitations, of which the tipping bucket rain gauge is the oldest and the most commonly used for the precipitations in-situ measurements. Each specific device properties can induces systematical occurring errors that can lead to statistical biases. For example, for low precipitation, the tipping bucket rain gauge, records false dry periods. So, during the past few years, other instruments more accurate than the tipping bucket rain gauge (eg disdrometer and weighting rain gauge) were placed for in-situ observation but their costs hinder the installation of large networks The present study focuses on the impact of the rain gauge volume. The aim is to define a minimal integration time according to the bucket volume for a given climatic region Our study focuses on Ile-de-France, this French region is a relatively dry region if we consider the annual amount of precipitation: 600 mm, a rainy region if we consider the number of days of precipitation per year: 160 days. It records Strong storm events sometimes but its precipitations are dominated by low rainfall. Eight year time series observed with a disdrometer and different rain gauges located on the French Atmospheric Research Observatory (SIRTA) , are used. Simulated tipping bucket rain gauge series for different tipping bucket volumes and weighting rain gauge series for different weights as precision are performed. The
Discrete-Time Mixing Receiver Architecture for RF-Sampling Software-Defined Radio
Ru, Z.; Klumperink, Eric A.M.; Nauta, Bram
2010-01-01
Abstract—A discrete-time (DT) mixing architecture for RF-sampling receivers is presented. This architecture makes RF sampling more suitable for software-defined radio (SDR) as it achieves wideband quadrature demodulation and wideband harmonic rejection. The paper consists of two parts. In the first
A Defining Time for Physical Education Futures? Exploring the Legacy of Fritz Duras
Kirk, David
2014-01-01
This paper explores the legacy of Dr Fritz Duras in order to address the issue of whether the implementation of a new curriculum for health and physical education in Australia represents a defining time for the subject. Dr Duras was Director of the first physical education teacher education course at the University of Melbourne during an earlier…
Transient habitats limit development time for periodical cicadas.
Karban, Richard
2014-01-01
Periodical cicadas (Magicicada spp.) mature in 13 or 17 years, the longest development times for any non-diapausing insects. Selection may favor prolonged development since nymphs experience little mortality and individuals taking 17 years have been shown to have greater fecundity than those taking 13 years. Why don't periodical cicadas take even longer to develop? Nymphs feed on root xylem fluid and move little. Ovipositing females prefer fast-growing trees at forest edges. I hypothesized that (1) adults emerging at edges would be heavier than those from forest interiors and (2) habitat changes could limit development time. I collected newly eclosed females that had neither fed as adults nor moved from their site of development. For M. septendecim, females from edges were 4.9% heavier than those from the interior. I assumed that emergence density indicated habitat quality and measured density at eight sites in 1979, 1996, and 2013. Over three generations, variation in densities was great; densities at two sites crashed, and at one site they exploded to 579/m2 Habitat transience may limit development time because only adults can reassess habitats and reposition offspring. In conclusion, cicadas are affected by habitat characteristics, habitats change over 17 years, and cicadas may emerge, mate, and redistribute their offspring to track habitat dynamics.
Lagrangian structures in time-periodic vortical flows
Directory of Open Access Journals (Sweden)
S. V. Kostrykin
2006-01-01
Full Text Available The Lagrangian trajectories of fluid particles are experimentally studied in an oscillating four-vortex velocity field. The oscillations occur due to a loss of stability of a steady flow and result in a regular reclosure of streamlines between the vortices of the same sign. The Eulerian velocity field is visualized by tracer displacements over a short time period. The obtained data on tracer motions during a number of oscillation periods show that the Lagrangian trajectories form quasi-regular structures. The destruction of these structures is determined by two characteristic time scales: the tracers are redistributed sufficiently fast between the vortices of the same sign and much more slowly transported into the vortices of opposite sign. The observed behavior of the Lagrangian trajectories is quantitatively reproduced in a new numerical experiment with two-dimensional model of the velocity field with a small number of spatial harmonics. A qualitative interpretation of phenomena observed on the basis of the theory of adiabatic chaos in the Hamiltonian systems is given. The Lagrangian trajectories are numerically simulated under varying flow parameters. It is shown that the spatial-temporal characteristics of the Lagrangian structures depend on the properties of temporal change in the streamlines topology and on the adiabatic parameter corresponding to the flow. The condition for the occurrence of traps (the regions where the Lagrangian particles reside for a long time is obtained.
Mimicking Nonequilibrium Steady States with Time-Periodic Driving
Raz, O.; Subaşı, Y.; Jarzynski, C.
2016-04-01
Under static conditions, a system satisfying detailed balance generically relaxes to an equilibrium state in which there are no currents. To generate persistent currents, either detailed balance must be broken or the system must be driven in a time-dependent manner. A stationary system that violates detailed balance evolves to a nonequilibrium steady state (NESS) characterized by fixed currents. Conversely, a system that satisfies instantaneous detailed balance but is driven by the time-periodic variation of external parameters—also known as a stochastic pump (SP)—reaches a periodic state with nonvanishing currents. In both cases, these currents are maintained at the cost of entropy production. Are these two paradigmatic scenarios effectively equivalent? For discrete-state systems, we establish a mapping between nonequilibrium stationary states and stochastic pumps. Given a NESS characterized by a particular set of stationary probabilities, currents, and entropy production rates, we show how to construct a SP with exactly the same (time-averaged) values. The mapping works in the opposite direction as well. These results establish a proof of principle: They show that stochastic pumps are able to mimic the behavior of nonequilibrium steady states, and vice versa, within the theoretical framework of discrete-state stochastic thermodynamics. Nonequilibrium steady states and stochastic pumps are often used to model, respectively, biomolecular motors driven by chemical reactions and artificial molecular machines steered by the variation of external, macroscopic parameters. Our results loosely suggest that anything a biomolecular machine can do, an artificial molecular machine can do equally well. We illustrate this principle by showing that kinetic proofreading, a NESS mechanism that explains the low error rates in biochemical reactions, can be effectively mimicked by a constrained periodic driving.
How to Define the Equality of Durations in Measurement of Time
Institute of Scientific and Technical Information of China (English)
ZHAO Zheng; TIAN Gui-Hua; LIU Liao; GAO Si-Jie
2006-01-01
We develop the research on measurement of time worked by Poincaré, Einstein, Landau and other researchers.Based on the convention that the velocity of light is isotropic and is a constant in empty spacetime, we not only answer the question about the definition of the synchronization of rate of clocks located at different places, but also find the solution to the issue of how to define the equality of two durations in measurement of time.
Almost Periodically Correlated Time Series in Business Fluctuations Analysis
Lenart, Lukasz
2012-01-01
We propose a non-standard subsampling procedure to make formal statistical inference about the business cycle, one of the most important unobserved feature characterising fluctuations of economic growth. We show that some characteristics of business cycle can be modelled in a non-parametric way by discrete spectrum of the Almost Periodically Correlated (APC) time series. On the basis of estimated characteristics of this spectrum business cycle is extracted by filtering. As an illustration we characterise the man properties of business cycles in industrial production index for Polish economy.
On the local integrability of almost-product structures defined by space-time metrics
Delphenich, D H
2016-01-01
The splitting of the tangent bundle of space-time into temporal and spatial sub-bundles defines an almost-product structure. In particular, any space-time metric can be locally expressed in time-orthogonal form, in such a way that whether or not that almost-product structure is locally generated by a coordinate chart is a matter of the integrability of the Pfaff equation that the temporal 1-form of that expression for the metric defines. When one applies that analysis to the known exact solutions to the Einstein field equations, one finds that many of the common ones are completely-integrable, although some of the physically-interesting ones are not.
Desensitization to media violence over a short period of time.
Fanti, Kostas A; Vanman, Eric; Henrich, Christopher C; Avraamides, Marios N
2009-01-01
This study investigated the desensitization to violence over a short period of time. Participants watched nine violent movie scenes and nine comedy scenes, and reported whether they enjoyed the violent or comedy scenes and whether they felt sympathetic toward the victim of violence. Using latent growth modeling, analyses were carried out to investigate how participants responded to the different scenes across time. The findings of this study suggested that repeated exposure to media violence reduces the psychological impact of media violence in the short term, therefore desensitizing viewers to media violence. As a result, viewers tended to feel less sympathetic toward the victims of violence and actually enjoy more the violence portrayed in the media. Additionally, desensitization to media violence was better represented by a curvilinear pattern, whereas desensitization to comedy scenes was better represented by a linear pattern. Finally, trait aggression was not related to the pattern of change over time, although significant effects were found for initial reports of enjoyment and sympathy.
Swimming and transport of bacteria in time-periodic flows
Winter, Rebecca; Patteson, Alison; Gagnon, David; Arratia, Paulo
The transport of bacteria can be highly influenced by external flows in oceans, rivers, and intestinal tracts. This has implications in biological systems for the performance of major biological processes, such as biofilm formation. In this study, we experimentally investigate the aggregation and transport of swimming Vibrio cholerae bacteria in time-periodic flows. Bacteria are placed in a well-characterized flow, and bacterial concentrations are recorded for a range of Reynolds numbers (Re) that spans two orders of magnitude, from 0.1 to 10. It is generally found that bacteria deplete from regions of high deformation rate and accumulate near vortices. This phenomenon seems to be dictated by a combination of bacterial activity and background flow vorticity. R.W. supported by NSF-GRFP.
Relaxation Characteristics of 828 DGEBA Epoxy Over Long Time Periods
Hoo, Jasmine; Reprogle, Riley C.; Wisler, Brian; Arechederra, Gabriel K.; McCoy, John D.; Kropka, Jamie M.; Long, Kevin N.
The mechanical relaxation response in uniaxial compression of a diglycidyl ether of bisphenol-A epoxy was studied over long time periods. The epoxy, 828DEA, was Epon 828 cured with diethanolamine (DEA). A sample was compressed at constant strain rate and held at various strain levels for days to allow the sample to relax. The sample was then compressed further and held once more. The relaxation curves were fit with a stretched exponential function. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.
Navy Global Predictions for the Dynamo Time Period
Reynolds, C. A.; Ridout, J. A.; Flatau, M. K.; Chen, J.; Richman, J. G.; Jensen, T. G.; Shriver, J. F.
2014-12-01
The performance of 30-day simulations of the Navy Global Environmental Model (NAVGEM) is evaluated under several metrics. The time period of interest is the DYNAMO (Dynamics of Madden Julian Oscillation) field experiment period, starting late October 2011. The NAVGEM experiments are run at an effective 37-km resolution with several different SST configurations. The in the first set of experiments, the initial SST analysis, provided by the NCODA (Navy Coupled Ocean Data Assimilation) system, is either held fixed to the initial value (fixed SST) or updated every 6 hours. These forecasts are compared with forecasts in which the SST is updated with 3-h analyses from the Hybrid Coordinate Ocean Model (HYCOM), and forecasts in which NAVGEM is interactively coupled to HYCOM. Experiments are also performed with different physical parameterization options. The extended integrations are verified using observed OLR, TRMM precipitation estimates, and global analyses. The use of fixed SSTs is clearly sub-optimal. Biases in monthly mean fields are far more pronounced in the simulations where the SST is held fixed as compared to those in simulations where updated SST analyses are used. Biases in the monthly mean fields are further reduced when NAVGEM is coupled to HYCOM. Differences in SST can "migrate" to substantial changes in the time-mean land-surface temperatures, illustrating the substantial impact of SSTs over the full domain. Concerning the simulation of the MJO, some improvement is noted when the system is fully coupled, although the simulations still exhibit deficiencies such as eastward propagation that is too slow, and difficulty propagating over the maritime continent. Simulations that are started every 5 days indicate that the NAVGEM uncoupled system has difficulty predicting MJO initiation, but simulations started when the MJO is active in the Indian Ocean are able to capture eastward propagation characteristics. The coupled NAVGEM-HYCOM system shows ability to
Adaptive stabilization of discrete-time systems using linear periodically time varying controllers
Ortega, Romeo; Albertos, Pedro; Lozano, Rogelio
1988-01-01
A direct adaptive scheme based on the use of linear time-varying periodic controllers is proposed which estimates online the periodic coefficients of the controller. It is shown that adaptive stabilization is attained for all possibly nonstably invertible plants of known order but unknown delay. Although no appeal is made to persistency of excitation arguments, a provision is needed to avoid the singularity of an estimated matrix, this property being required only for the analysis and not the control calculations.
Energy Technology Data Exchange (ETDEWEB)
Yang, Ping-Fan; Guo, Yong, E-mail: guoy66@tsinghua.edu.cn [Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)
2016-02-01
We investigate the tunneling time (dwell time) in periodic diluted-magnetic-semiconductor/nonmagnetic-barrier (DMS/NB) superlattices subjected to an external magnetic field. It is found that spin-dependent resonant bands form in the spectra of dwell time, which can be effectively manipulated by not only the external magnetic field but also the geometric parameters of the system. Moreover, an intuitive semiclassical delay is defined to illustrate the behavior of the dwell time, and the former one is shown to be the result of “smoothing out” the latter one. We also find that the dwell time in diluted-magnetic-semiconductor/semiconductor superlattices behaves surprisingly different from the DMS/NB case, especially for spin-down electrons.
Wiese, B I; Hendrick, S; Campbell, J G; McKinnon, J J; Beauchemin, K A; McAllister, T A; Penner, G B
2017-01-01
The objective of the current study was to measure reticuloruminal pH in cattle in a commercial feedlot setting to determine the incidence and extent of low reticuloruminal pH for steers and heifers as they transition to a high-concentrate finishing diet. Reticuloruminal pH was measured in 16 "mixed breed" steers (4 steers/pen with 4 pens) and 16 "mixed breed" heifers (4 heifers/pen with 4 pens) housed in commercial feedlot pens, with 227 ± 13 and 249 ± 6 cattle/pen cohort steers and heifers, respectively, for the diet transition period. Cattle were transitioned from a diet of 53.5% forage and 46.5% concentrate to a diet of 9.5% forage and 90.5% concentrate on a DM basis using a 40-d transition with 5 dietary steps with the diets containing 41.4, 44.8, 49.8, 52.5, 55.1, and 64.0% nonfibrous carbohydrate. In addition, wheat replaced barley as the grain source during the dietary transition. Reticuloruminal pH was measured using orally administered pH measurement devices that were retrieved at slaughter. Data were analyzed using a mixed model including the fixed effects of sex, diet, and the 2-way interaction to evaluate the effect of diet and sex and with the fixed effects of sex, diet, and day relative to each dietary change along with the 2- and 3-way interactions to evaluate temporal responses as a result of diet change. A repeated measures statement was included for the effect of day. Both the mean and minimum reticuloruminal pH values decreased as the proportion of concentrate in the diet increased ( pH was pH, defined as pH 180 min, increased with increasing concentrate, and by the end of the 40-d dietary transition, 83% of the cattle had experienced at least 1 bout of low reticuloruminal pH, with most experiencing between 1 and 3 bouts/diet. These data are interpreted to suggest that cattle are at high risk for experiencing low reticuloruminal pH during the dietary transition but that the extent of low reticuloruminal pH is mild. Moreover, the data suggest
Defining a Trend for a Time Series Which Makes Use of the Intrinsic Time-Scale Decomposition
Restrepo, Juan M; Comeau, Darin; Flaschka, Hermann
2014-01-01
We propose criteria that define a trend for time series with inherent multi-scale features. We call this trend the {\\it tendency} of a time series. The tendency is defined empirically by a set of criteria and captures the large-scale temporal variability of the original signal as well as the most frequent events in its histogram. Among other properties, the tendency has a variance no larger than that of the original signal; the histogram of the difference between the original signal and the tendency is as symmetric as possible; and with reduced complexity, the tendency captures essential features of the signal. To find the tendency we first use the Intrinsic Time-Scale Decomposition (ITD) of the signal, introduced in 2007 by Frei and Osorio, to produce a set of candidate tendencies. We then apply the criteria to each of the candidates to single out the one that best agrees with them. While the criteria for the tendency are independent of the signal decomposition scheme, it is found that the ITD is a simple an...
Molecular response properties from a Hermitian eigenvalue equation for a time-periodic Hamiltonian.
Pawłowski, Filip; Olsen, Jeppe; Jørgensen, Poul
2015-03-21
The time-dependent Schrödinger equation for a time-periodic perturbation is recasted into a Hermitian eigenvalue equation, where the quasi-energy is an eigenvalue and the time-periodic regular wave function an eigenstate. From this Hermitian eigenvalue equation, a rigorous and transparent formulation of response function theory is developed where (i) molecular properties are defined as derivatives of the quasi-energy with respect to perturbation strengths, (ii) the quasi-energy can be determined from the time-periodic regular wave function using a variational principle or via projection, and (iii) the parametrization of the unperturbed state can differ from the parametrization of the time evolution of this state. This development brings the definition of molecular properties and their determination on par for static and time-periodic perturbations and removes inaccuracies and inconsistencies of previous response function theory formulations. The development where the parametrization of the unperturbed state and its time evolution may differ also extends the range of the wave function models for which response functions can be determined. The simplicity and universality of the presented formulation is illustrated by applying it to the configuration interaction (CI) and the coupled cluster (CC) wave function models and by introducing a new model-the coupled cluster configuration interaction (CC-CI) model-where a coupled cluster exponential parametrization is used for the unperturbed state and a linear parametrization for its time evolution. For static perturbations, the CC-CI response functions are shown to be the analytical analogues of the static molecular properties obtained from finite field equation-of-motion coupled cluster (EOMCC) energy calculations. The structural similarities and differences between the CI, CC, and CC-CI response functions are also discussed with emphasis on linear versus non-linear parametrizations and the size-extensivity of the obtained
7 CFR 1.603 - How are time periods computed?
2010-01-01
... as follows: (1) The day of the act or event from which the period begins to run is not included. (2... delay in filing. (iii) The ALJ may grant the extension only if: (A) It would not unduly prejudice...
Logic Model Checking of Time-Periodic Real-Time Systems
Florian, Mihai; Gamble, Ed; Holzmann, Gerard
2012-01-01
In this paper we report on the work we performed to extend the logic model checker SPIN with built-in support for the verification of periodic, real-time embedded software systems, as commonly used in aircraft, automobiles, and spacecraft. We first extended the SPIN verification algorithms to model priority based scheduling policies. Next, we added a library to support the modeling of periodic tasks. This library was used in a recent application of the SPIN model checker to verify the engine control software of an automobile, to study the feasibility of software triggers for unintended acceleration events.
She, M.; Jiang, L. P.
2014-12-01
In this paper, an oscillating dark energy model is presented in an isotropic but inhomogeneous plane symmetric space-time by considering a time periodic varying deceleration parameter. We find three different types of new solutions which describe different scenarios of oscillating universe. The first two solutions show an oscillating universe with singularities. For the third one, the universe is singularity-free during the whole evolution. Moreover, the Hubble parameter oscillates and keeps positive which explores an interesting possibility to unify the early inflation and late time acceleration of the universe.
Controlling mixing and segregation in time periodic granular flows
Bhattacharya, Tathagata
of realistic results and is used as a means of validating the model against available experimental data. The tuned model is then used to find the critical chute length for segregation based on the hypothesis that segregation can be thwarted if the particle flow is inverted at a rate above a critical forcing frequency. The critical frequency, fcrit, is inversely proportional to the characteristic time of segregation, ts. Mixing is observed instead of segregation when the chute length L screens or flotation methods. This approach is based on differences in the kinetic properties of the components of a mixture, such as the velocity of migration or diffusivity. In this portion of the work, two examples of novel rate-based separation devices are demonstrated. The first example involves the study of the dynamics of gravity-driven particles through an array of obstacles. Both discrete element (DEM) simulations and experiments are used to augment the understanding of this device. Dissipative collisions (both between the particles themselves and with the obstacles) give rise to a diffusive motion of particles perpendicular to the flow direction and the differences in diffusion lengths are exploited to separate the particles. The second example employs DEM to analyze a ratchet mechanism where a current of particles can be produced in a direction perpendicular to the energy input. In this setup, a vibrating saw-toothed base is employed to induce different mobility for different types of particles. The effect of operating conditions and design parameters on the separation efficiency are discussed. Keywords: granular flow, particle, mixing, segregation, discrete element method, particle dynamics, tumbler, chute, periodic flow inversion, collisional flow, rate-based separation, ratchet, static separator, dissipative particle dynamics, non-spherical droplet.
Zhao, Guangyu; Ruan, Shigui
2011-06-01
We study the existence, uniqueness, and asymptotic stability of time periodic traveling wave solutions to a periodic diffusive Lotka-Volterra competition system. Under certain conditions, we prove that there exists a maximal wave speed c(*) such that for each wave speed c ≤ c(*), there is a time periodic traveling wave connecting two semi-trivial periodic solutions of the corresponding kinetic system. It is shown that such a traveling wave is unique modulo translation and is monotone with respect to its co-moving frame coordinate. We also show that the traveling wave solutions with wave speed c c(*).
Zhao, Guangyu; Ruan, Shigui
2011-01-01
We study the existence, uniqueness, and asymptotic stability of time periodic traveling wave solutions to a periodic diffusive Lotka-Volterra competition system. Under certain conditions, we prove that there exists a maximal wave speed c* such that for each wave speed c ≤ c*, there is a time periodic traveling wave connecting two semi-trivial periodic solutions of the corresponding kinetic system. It is shown that such a traveling wave is unique modulo translation and is monotone with respect to its co-moving frame coordinate. We also show that the traveling wave solutions with wave speed c c*. PMID:21572575
Time Periodic Control of a Multi-Blade Helicopter.
1988-05-01
motion (13-22). Friedmann and Silverthorn (13) examined the flap-lag motion of a cantilevered rotor blade at arbitrary d, advance ratios. They concluded...Advance Ratio,* NASA SP-352: 25-34 (1974). 13. Friedmann, P. and L. J. Silverthorn . "Aeroelastic Stability of Periodic Systems with Applications to Rotor
Periodic Solutions of a Discrete Time Predator-Prey System
Institute of Scientific and Technical Information of China (English)
Yong-li Song; Mao-an Han
2006-01-01
In this paper, we discuss a discrete predator-prey system with a non-monotonic functional response,which models the dynamics of the prey and the predator having non-overlapping generations. By using the coincidence degree theory, sufficient conditions are obtained for the existence of positive periodic solutions.
Institute of Scientific and Technical Information of China (English)
Jing HUI; Lan Sun CHEN
2004-01-01
The general system of differential equations describing predator-prey dynamics with impulsive effects is modified by the assumption that the coefficients are periodic functions of time. By use of standard techniques of bifurcation theory, it is known that this system has a positive periodic solution provided the time average of the predator's net uninhibited death rate is in a suitable range.The bifurcation is from the periodic solution of the time-dependent logistic equation for the prey (which results in the absence of predator).
Indian Academy of Sciences (India)
BASANT K JHA; BABATUNDE AINA
2016-08-01
This work reports an analytical solution for fully developed mixed convection flow of viscous,incompressible, electrically conducting fluid in vertical concentric annuli under the influence of a transverse magnetic field, where the outer surface of inner cylinder is heated sinusoidally and the inner surface of outercylinder is kept at a constant temperature. The analysis is carried out for fully developed parallel flow and steady-periodic regime. The governing dimensionless momentum and energy equations are separated into steadyand periodic parts and solved analytically. Closed form solutions are expressed in terms of modified Bessel function of first and second kind. The influence of each governing parameters such as magnetic field parameter,Prandtl number and the dimensionless frequency of heating on flow formation and thermal behaviour are discussed with the aid of graphs. During the course of investigation, it is found that the oscillation amplitude of the friction factor is maximized at a resonance frequency near the surface of the concentric annuli where there is periodic heating. Furthermore, increasing transverse magnetic field decreases the oscillation amplitude of the friction factor.
Using travel times to simulate multi-dimensional bioreactive transport in time-periodic flows.
Sanz-Prat, Alicia; Lu, Chuanhe; Finkel, Michael; Cirpka, Olaf A
2016-04-01
In travel-time models, the spatially explicit description of reactive transport is replaced by associating reactive-species concentrations with the travel time or groundwater age at all locations. These models have been shown adequate for reactive transport in river-bank filtration under steady-state flow conditions. Dynamic hydrological conditions, however, can lead to fluctuations of infiltration velocities, putting the validity of travel-time models into question. In transient flow, the local travel-time distributions change with time. We show that a modified version of travel-time based reactive transport models is valid if only the magnitude of the velocity fluctuates, whereas its spatial orientation remains constant. We simulate nonlinear, one-dimensional, bioreactive transport involving oxygen, nitrate, dissolved organic carbon, aerobic and denitrifying bacteria, considering periodic fluctuations of velocity. These fluctuations make the bioreactive system pulsate: The aerobic zone decreases at times of low velocity and increases at those of high velocity. For the case of diurnal fluctuations, the biomass concentrations cannot follow the hydrological fluctuations and a transition zone containing both aerobic and obligatory denitrifying bacteria is established, whereas a clear separation of the two types of bacteria prevails in the case of seasonal velocity fluctuations. We map the 1-D results to a heterogeneous, two-dimensional domain by means of the mean groundwater age for steady-state flow in both domains. The mapped results are compared to simulation results of spatially explicit, two-dimensional, advective-dispersive-bioreactive transport subject to the same relative fluctuations of velocity as in the one-dimensional model. The agreement between the mapped 1-D and the explicit 2-D results is excellent. We conclude that travel-time models of nonlinear bioreactive transport are adequate in systems of time-periodic flow if the flow direction does not change
Time trends and periodic cycles in REM sleep eye movements.
Krynicki, V
1975-11-01
Eye movements during REM sleep episodes were tabulated in 16 young adults. REM episodes were then broken down into four ranges according to length in min: (1) 11.0-21.3; (2) 21.7-29.7; (3) 30.0-42.3; (4) 42.7 or longer. These data were then analyzed for linear and quadratic trends. Eight episodes had a significant linear trend, 10 had a significant quadratic trend, 7 had both linear and quadratic trends, while 12 had no trend. The residuals from the best-fitting polynomial curve were then subject to a spectral analysis. In addition, 2 long periods of pre-sleep wakefulness (approximately 2 h each) were also analyzed. In general, the spectral analysis revealed the dominant presence of a slow cycle (period of 10 min to about 30 min) the exact period of which varied according to the length of the REM episode. A binomial probability test indicated that the presence of slow cycles was significant in REM episodes except for those in the 21-30 min range. For the episodes of wakefulness, a dominant slow cycle was found in both cases. The results give the impression of similarity in the periodic organization of eye movements during REM sleep and waking. The data also indicated that an ultradian (70-150 min) cycle was present in eye movements during sleep and waking. Further, the finding of a decrease in eye movements before sleep onset, coupled with previous reports of an increase in eye movement after sleep onset, indicate the presence of a circadian cycle.
Primate enamel evinces long period biological timing and regulation of life history.
Bromage, Timothy G; Hogg, Russell T; Lacruz, Rodrigo S; Hou, Chen
2012-07-21
The factor(s) regulating the combination of traits that define the overall life history matrix of mammalian species, comprising attributes such as brain and body weight, age at sexual maturity, lifespan and others, remains a complete mystery. The principal objectives of the present research are (1) to provide evidence for a key variable effecting life history integration and (2) to provide a model for how one would go about investigating the metabolic mechanisms responsible for this rhythm. We suggest here that a biological rhythm with a period greater than the circadian rhythm is responsible for observed variation in primate life history. Evidence for this rhythm derives from studies of tooth enamel formation. Enamel contains an enigmatic periodicity in its microstructure called the striae of Retzius, which develops at species specific intervals in units of whole days. We refer to this enamel rhythm as the repeat interval (RI). For primates, we identify statistically significant relationships between RI and all common life history traits. Importantly, RI also correlates with basal and specific metabolic rates. With the exception of estrous cyclicity, all relationships share a dependence upon body mass. This dependence on body mass informs us that some aspect of metabolism is responsible for periodic energy allocations at RI timescales, regulating cell proliferation rates and growth, thus controlling the pace, patterning, and co-variation of life history traits. Estrous cyclicity relates to the long period rhythm in a body mass-independent manner. The mass-dependency and -independency of life history relationships with RI periodicity align with hypothalamic-mediated neurosecretory anterior and posterior pituitary outputs. We term this period the Havers-Halberg Oscillation (HHO), in reference to Clopton Havers, a 17th Century hard tissue anatomist, and Franz Halberg, a long-time explorer of long-period rhythms. We propose a mathematical model that may help elucidate
Defining the optimal time to the operating room may salvage early trauma deaths.
Remick, Kyle N; Schwab, C William; Smith, Brian P; Monshizadeh, Amir; Kim, Patrick K; Reilly, Patrick M
2014-05-01
Early trauma deaths have the potential for salvage with immediate surgery. We studied time from injury to death in this group to qualify characteristics and quantify time to the operating room, yielding the greatest opportunity for salvage. The Pennsylvania Trauma Outcomes Study (PTOS) is a comprehensive registry including all Pennsylvania trauma centers. PTOS was queried for adult trauma patients from 1999 to 2010 dying within 4 hours of injury. The distribution of time to death (TD) was examined for subgroups according to mechanism of injury, hypotension (defined as systolic blood pressure ≤ 90 mm Hg), and operation required. The 5th percentile (TD5) and the 50th percentile (TD50) were calculated from the distributions and compared using the Mann-Whitney U-test. The PTOS yielded 6,547 deaths within 4 hours of injury. The overall TD5 and TD50 were 0:23 (hour:minute) and 0:59, respectively. Median penetrating injury times were significantly shorter than blunt injury times (TD5/TD50, 0:19/0:43 vs. 0:29/1:10). Median time was significantly shorter for hypotensive versus normotensive patients (TD5/TD50, 0:22/0:52 vs. 0:43/2:18). Operative subgroups had different TD5/TD50 (abdominal surgery [n = 607], 1:07/2:26; thoracic surgery [n = 756] 0:25/1:25; vascular surgery [n = 156], 0:35/2:15; and cranial surgery [n = 18], 1:20/2:42). Early trauma deaths have the potential for salvage with immediate surgery. We found TD to vary based on mechanism of injury, presence of hypotension, and type of surgery needed. With the use of TD5 and TD50 benchmarks in these subgroups, a trauma system may determine if decreased time to the operating room decreases mortality. Trauma systems can use these data to further improve prehospital and initial hospital phases of care for this subset of early death trauma patients. Epidemiologic study, level III.
A Method for Determining Periods in Time Series.
1981-04-01
SUPPLEMENTARY NOTES IS. KEY WORDS (Conlinu an revere cide Ii necesry d Identify by block nmi 9ber) Univariate time series; spectral density function ; Newton’s...and the method is applied to a series of hormone levels data. KEY WORDS: Univariate time series; Spectral density function ; Newton’s Method...Z the set of integers, be a zero mean covariance stationary time series with autocovariance function R(v) = E(Y(t)Y(t+v)), vZ and spectral density function f
Local time-decay of solutions to Schroedinger equations with time-periodic potentials
Galtbayar, A; Yajima, K
2002-01-01
Let $H(t)=-\\Delta+V(t,x)$ be a time-dependent Schr\\"{o}dinger operator on $L^2(\\R^3)$. We assume that $V(t,x)$ is $2\\pi$--periodic in time and decays sufficiently rapidly in space. Let $U(t,0)$ be the associated propagator. For $u_0$ belonging to the continuous spectral subspace of $L^2(\\R^3)$ for the Floquet operator $U(2\\pi, 0)$, we study the behavior of $U(t,0)u_0$ as $t\\to\\infty$ in the topology of $x$-weighted spaces, in the form of asymptotic expansions. Generically the leading term is $t^{-3/2}B_1u_0$. Here $B_1$ is a finite rank operator mapping functions of $x$ to functions of $t$ and $x$, periodic in $t$. If $n\\in\\Z$ is an eigenvalue, or a threshold resonance of the corresponding Floquet Hamiltonian $-i\\pa_t + H(t)$, the leading behavior is $t^{-1/2}B_0u_0$. The point spectral subspace for $U(2\\pi, 0)$ is finite dimensional. If $U(2\\pi, 0)\\phi_j = e^{-i2\\pi\\l_j }\\phi_j$, then $U(t, 0)\\phi_j$ represents a quasi-periodic solution.
Delta T: Polynomial Approximation of Time Period 1620–2013
Directory of Open Access Journals (Sweden)
M. Khalid
2014-01-01
Full Text Available The difference between the Uniform Dynamical Time and Universal Time is referred to as ΔT (delta T. Delta T is used in numerous astronomical calculations, that is, eclipses,and length of day. It is additionally required to reduce quantified positions of minor planets to a uniform timescale for the purpose of orbital determination. Since Universal Time is established on the basis of the variable rotation of planet Earth, the quantity ΔT mirrors the unevenness of that rotation, and so it changes slowly, but rather irregularly, as time passes. We have worked on empirical formulae for estimating ΔT and have discovered a set of polynomials of the 4th order with nine intervals which is accurate within the range of ±0.6 seconds for the duration of years 1620–2013.
Transient aggregation and long-time diffusion of bacterial suspensions in time periodic flows
Qin, Boyang; Winter, Rebecca; Gurjar, Madhura; Gagnon, David; Patteson, Alison; Arratia, Paulo
2016-11-01
In this talk, the transport dynamics of swimming bacteria in time-periodic flows is investigated in experiments and simulations. Experiments are performed by introducing swimming bacteria (Vibrio cholerae) in a low Reynolds number, two-dimensional flow driven electromagnetically. We observe two distinct transport regimes: (i) entrapment of bacteria inside vortex and near elliptic points and (ii) aggregation and subsequent transport along the flow manifolds. These time-dependent behaviors are set by the interaction between swimmer kinematics (e.g. speed, tumbling frequency, etc) and flow properties. Numerical simulation using a stochastic Langevin model are able to capture the main experimental results including the entrapment of bacteria near elliptic points and the rapid spreading along manifolds. Results show a significant reduction in long-time effective diffusion of the swimmer as vortex strength is increased. The conditions for bacterial entrapment in vortex flows are discussed.
Spiegelhalder, Kai; Regen, Wolfram; Kyle, Simon D; Endres, Dominique; Nissen, Christoph; Feige, Bernd; Riemann, Dieter
2012-06-01
Primary insomnia is a prevalent sleep disorder affecting approximately 3% of the general population. Studies suggest that personality traits such as perfectionism and neuroticism might be implicated in the aetiology of the disorder. However, to date, no study has investigated behavioural indicators of these factors in a hypothesis-driven manner. In the present study, we assessed punctuality as a behavioural indicator of perfectionism and neuroticism in 635 consecutive clinical patients of the sleep laboratory of the Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center. The primary aim was to compare primary insomnia patients (n = 148) with another group of patients with other sleep-related diagnoses (n = 487). Primary insomnia patients arrived on average 4 min earlier when compared to other patients (P = 0.041). However, this effect failed to reach statistical significance when correcting for the influence of potential confounding variables. Of note, we found a strong relationship between polysomnographic sleep parameters and punctuality. That is, short sleep duration was associated significantly with early arrival times at the sleep laboratory (P = 0.023). These findings support the proposal that personality traits, which we predict underlie obsessive punctuality, may be involved in the aetiology of objectively defined sleep disturbances. Clinical implications of the current results for cognitive behavioural treatments of insomnia are discussed.
Time-periodic Solution to a Nonlinear Parabolic Type Equation of Higher Order
Institute of Scientific and Technical Information of China (English)
Yan-ping Wang; You-lin Zhang
2008-01-01
In this paper, the existence and uniqueness of time-periodic generalized solutions and time-periodic classical solutions to a class of parabolic type equation of higher order are proved by Gaierkin method.
Time-Periodic Solution of a 2D Fourth-Order Nonlinear Parabolic Equation
Indian Academy of Sciences (India)
Xiaopeng Zhao; Changchun Liu
2014-08-01
By using the Galerkin method, we study the existence and uniqueness of time-periodic generalized solutions and time-periodic classical solutions to a fourth-order nonlinear parabolic equation in 2D case.
A Bloch-based procedure for dispersion analysis of lattices with periodic time-varying properties
Vila, Javier; Pal, Raj Kumar; Ruzzene, Massimo; Trainiti, Giuseppe
2017-10-01
We present a procedure for the systematic estimation of the dispersion properties of linear discrete systems with periodic time-varying coefficients. The approach relies on the analysis of a single unit cell, making use of Bloch theorem along with the application of a harmonic balance methodology over an imposed solution ansatz. The solution of the resulting eigenvalue problem is followed by a procedure that selects the eigen-solutions corresponding to the ansatz, which is a plane wave defined by a frequency-wavenumber pair. Examples on spring-mass superlattices demonstrate the effectiveness of the method at predicting the dispersion behavior of linear elastic media. The matrix formulation of the problem suggests the broad applicability of the proposed technique. Furthermore, it is shown how dispersion can inform about the dynamic behavior of time-modulated finite lattices. The technique can be extended to multiple areas of physics, such as acoustic, elastic and electromagnetic systems, where periodic time-varying material properties may be used to obtain non-reciprocal wave propagation.
Lima-Costa, Maria Fernanda; Matos, Divane Leite; Laurenti, Ruy; Mello-Jorge, Maria Helena Prado de; Cesar, Cibele Comini
2010-03-01
The study objective was to examine differentials in time trends and predictors of deaths assigned to symptoms, signs and ill-defined conditions in comparison with other ill-defined conditions (ill-defined cardiovascular diseases, cancer and injury) in a population-based cohort study. Of 1,606 baseline participants aged 60 years and over, 524 died during 9-year follow-up and were included in this study. Deaths coded to "symptoms" declined by 77% in the period from 1997-1999 to 2003-2005. Deaths coded to other ill-defined conditions remained unchanged. The calendar period 2003-2005 (RR = 0.25; 95%CI: 0.09-0.70) and in-hospital deaths (RR = 0.16; 95%CI: 0.08-0.34) were independently associated with "symptoms", but not with other ill-defined conditions. Baseline socio-demographic characteristics and chronic diseases were not predictors of these outcomes. International and national agencies have focused on the reduction of deaths assigned to "symptoms" to improve the registration of vital statistics, while other ill-defined conditions have received little attention. Our data provide evidence supporting the need to redress this situation.
The risk of AIDS-defining events is decreasing over time in the German HIV-1 Seroconverter Cohort
Directory of Open Access Journals (Sweden)
Altmann Mathias
2012-04-01
Full Text Available Abstract Background With ageing of the HIV-infected population, long-term exposure to treatment, varying adherence, emerging resistance and complications to therapies, effectiveness of Highly Active Antiretroviral Therapy (HAART needs to be monitored continuously at the population level. The German HIV-1 Seroconverter Cohort is a multi-centre, open, long-term observational cohort including patients with a known or reliably estimated date of HIV-infection i.e. last negative and first positive HIV antibody test within a maximum three-year interval or laboratory evidence of seroconversion. Our study aims to investigate survival improvements and changes in AIDS risk over calendar periods in the German HIV-1 Seroconverter Cohort. Methods Retrospective (for the pre-1997 period and prospective (since 1997 data from the German HIV-1 Seroconverter Cohort were used. Time from seroconversion to first AIDS-defining event over calendar periods was analysed by using Cox models adjusting for age at seroconversion, sex, transmission groups and short HIV test interval. Kaplan-Meier methods were used to determine expected survival (remaining AIDS-free by calendar period. Results 2162 seroconverters with 8976 person-years of observation were included in our analysis (up to 31.12.2010. A total of 196 first AIDSdefining events were reported. Two periods i.e. 19972000 and 2007-2010 were statistically associated with a reduction in the risk of AIDS, accounting for an overall reduction of 80%. Compared to1997-2000, hazard ratios were 2.6 (95%CI, 1.6-4.8; p=0.000 in pre-1997 and 0.5 (95%CI, 0.3-0.8; p=0.007 in 20072010. Independent risk factor for AIDS progression was age at seroconversion (HR, 1.3 per 10year-increase; p=0.001. Conclusion HAART effectiveness has improved in the German HIV-1-Seroconverter Cohort. The risk to develop AIDS decreased significantly in 19972000 and in 20072010. However, elderly may require particular monitoring in view of their faster
Defining the Microglia Response during the Time Course of Chronic Neurodegeneration.
Vincenti, James E; Murphy, Lita; Grabert, Kathleen; McColl, Barry W; Cancellotti, Enrico; Freeman, Tom C; Manson, Jean C
2015-12-30
Inflammation has been proposed as a major component of neurodegenerative diseases, although the precise role it plays has yet to be defined. We examined the role of key contributors to this inflammatory process, microglia, the major resident immune cell population of the brain, in a prion disease model of chronic neurodegeneration. Initially, we performed an extensive reanalysis of a large study of prion disease, where the transcriptome of mouse brains had been monitored throughout the time course of disease. Our analysis has provided a detailed classification of the disease-associated genes based on cell type of origin and gene function. This revealed that the genes upregulated during disease, regardless of the strain of mouse or prion protein, are expressed predominantly by activated microglia. In order to study the microglia contribution more specifically, we established a mouse model of prion disease in which the 79A murine prion strain was introduced by an intraperitoneal route into BALB/cJ(Fms-EGFP/-) mice, which express enhanced green fluorescent protein under the control of the c-fms operon. Samples were taken at time points during disease progression, and histological analysis of the brain and transcriptional analysis of isolated microglia was carried out. The analysis of isolated microglia revealed a disease-specific, highly proinflammatory signature in addition to an upregulation of genes associated with metabolism and respiratory stress. This study strongly supports the growing recognition of the importance of microglia within the prion disease process and identifies the nature of the response through gene expression analysis of isolated microglia. Inflammation has been proposed as a major component of neurodegenerative diseases. We have examined the role of key contributors to this inflammatory process, microglia, the major resident immune cell population of the brain, in a murine prion disease model of chronic neurodegeneration. Our study demonstrates
Hyperbolicity and Exponential Convergence of the Lax Oleinik Semigroup for Time Periodic Lagrangians
Morgado, Héctor Sánchez
2012-01-01
We prove exponential convergence to time-periodic states of the solutions of time-periodic Hamilton-Jacobi equations on the torus, assuming that the Aubry set is the union of a finite number of hyperbolic periodic orbits of the the Euler Lagrange flow. The period of limiting solutions is the least common multiple of the periods of the orbits in the Aubry set. This extends a result that we obtained in the autonomous case.
Quality control methods in accelerometer data processing: defining minimum wear time.
Directory of Open Access Journals (Sweden)
Carly Rich
Full Text Available BACKGROUND: When using accelerometers to measure physical activity, researchers need to determine whether subjects have worn their device for a sufficient period to be included in analyses. We propose a minimum wear criterion using population-based accelerometer data, and explore the influence of gender and the purposeful inclusion of children with weekend data on reliability. METHODS: Accelerometer data obtained during the age seven sweep of the UK Millennium Cohort Study were analysed. Children were asked to wear an ActiGraph GT1M accelerometer for seven days. Reliability coefficients(r of mean daily counts/minute were calculated using the Spearman-Brown formula based on the intraclass correlation coefficient. An r of 1.0 indicates that all the variation is between- rather than within-children and that measurement is 100% reliable. An r of 0.8 is often regarded as acceptable reliability. Analyses were repeated on data from children who met different minimum daily wear times (one to 10 hours and wear days (one to seven days. Analyses were conducted for all children, separately for boys and girls, and separately for children with and without weekend data. RESULTS: At least one hour of wear time data was obtained from 7,704 singletons. Reliability increased as the minimum number of days and the daily wear time increased. A high reliability (r = 0.86 and sample size (n = 6,528 was achieved when children with ≥ two days lasting ≥10 hours/day were included in analyses. Reliability coefficients were similar for both genders. Purposeful sampling of children with weekend data resulted in comparable reliabilities to those calculated independent of weekend wear. CONCLUSION: Quality control procedures should be undertaken before analysing accelerometer data in large-scale studies. Using data from children with ≥ two days lasting ≥10 hours/day should provide reliable estimates of physical activity. It's unnecessary to include only children
EXISTENCE OF TIME PERIODIC SOLUTIONS FOR A DAMPED GENERALIZED COUPLED NONLINEAR WAVE EQUATIONS
Institute of Scientific and Technical Information of China (English)
房少梅; 郭柏灵
2003-01-01
The time periodic solution problem of damped generalized coupled nonlinear wave equations with periodic boundary condition was studied. By using the Galerkin method to construct the approximating sequence of time periodic solutions, a priori estimate and Laray-Schauder fixed point theorem to prove the convergence of the approximate solutions, the existence of time periodic solutions for a damped generalized coupled nonlinear wave equations can be obtained.
Defining progression in nonmuscle invasive bladder cancer: it is time for a new, standard definition
Lamm, D.; Persad, R.; Brausi, M.; Buckley, R.; Witjes, J.A.; Palou, J.; Bohle, A.; Kamat, A.M.; Colombel, M.; Soloway, M.
2014-01-01
PURPOSE: Despite being one of the most important clinical outcomes in nonmuscle invasive bladder cancer, there is currently no standard definition of disease progression. Major clinical trials and meta-analyses have used varying definitions or have failed to define this end point altogether. A stand
Compact attractors for time-periodic age-structured population models
Directory of Open Access Journals (Sweden)
Pierre Magal
2001-10-01
Full Text Available In this paper we investigate the existence of compact attractors for time-periodic age-structured models. So doing we investigate the eventual compactness of a class of abstract non-autonomous semiflow (non necessarily periodic. We apply this result to non-autonomous age-structured models. In the time periodic case, we obtain the existence of a periodic family of compact subsets that is invariant by the semiflow, and attract the solutions of the system.
Time-periodic solutions of the Einstein’s field equations II:geometric singularities
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
In this paper,we construct several kinds of new time-periodic solutions of the vacuum Einstein’s field equations whose Riemann curvature tensors vanish,keep finite or take the infinity at some points in these space-times,respectively.The singularities of these new time-periodic solutions are investigated and some new physical phenomena are discovered.
Linear Impulsive Periodic System with Time-Varying Generating Operators on Banach Space
Directory of Open Access Journals (Sweden)
Wei W
2007-01-01
Full Text Available A class of the linear impulsive periodic system with time-varying generating operators on Banach space is considered. By constructing the impulsive evolution operator, the existence of -periodic -mild solution for homogeneous linear impulsive periodic system with time-varying generating operators is reduced to the existence of fixed point for a suitable operator. Further the alternative results on -periodic -mild solution for nonhomogeneous linear impulsive periodic system with time-varying generating operators are established and the relationship between the boundness of solution and the existence of -periodic -mild solution is shown. The impulsive periodic motion controllers that are robust to parameter drift are designed for a given periodic motion. An example given for demonstration.
Time-periodic solutions of the Einstein’s field equations Ⅰ:general framework
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
In this paper,we develop a new algorithm to find the exact solutions of the Einstein’s field equations.Time-periodic solutions are constructed by using the new algorithm.The singularities of the time-periodic solutions are investigated and some new physical phenomena,such as degenerate event horizon and time-periodic event horizon,are found.The applications of these solutions in modern cosmology and general relativity are expected.
EXISTENCE OF PERIODIC SOLUTIONS FOR A DISCRETE-TIME MODEL OF TWO-CELL CNNS
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
We investigate a class of discrete-time model of two-cell cellular neural networks with symmetric template. By using the Lyapunov direct method, La-Salle's invariance principle, we discuss the existence and the stability of periodic solutions. The model considered has attractive 2-periodic and unstable 2-periodic solutions.
Directory of Open Access Journals (Sweden)
Yu. I. Shapovalov
2015-03-01
Full Text Available Introduction. The architecture of MAOPCs functions system and examples of its application for solving the tasks of multivariate analysis of linear periodically time-variable (LPTV circuits based on the frequency symbolic method are considered in this paper. The method is based on approximation of transfer functions of LPTV circuits in the form of trigonometric polynomials of the Fourier. The MAOPCs functions system is implemented in the environment of MATLAB. Architecture and functions of the system MAOPCs. The system consists of 17 functions that are implemented in the environment of MATLAB. Each function has arguments and global variables and carries out over them identified transformation. Functions and global variables form the input data program for research LPTV circuit and should be defined (set at the time of calling the function. Conclusions. The MAOPCs functions system enables to investigate LPTV circuits, setting in program input data the algorithms for their research and to use a strong symbolic apparatus and other standard functions of the package MATLAB in full, without understanding the deep of mathematical apparatus of implemented methods.
Time-variation of the near 5-month period of sunspot numbers
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
The variation of the near 5-month period of sunspot numbers is discussed on the basis of the wavelet transform of the daily sunspot number series in the 14th-22nd solar cycles. The result shows that the period exists in every cycle and its energy density (amplitude) is comparatively large in the peak section of the cycle. In the distinct cycle, the length and intensity of the period is different, which means that the period varies with time. The near 25-day period is also analyzed and it is found to be time- variable and even not very stable in the peak section of the cycle. The variations of the two periods show that the near 5-month period should not be simply regarded as the multiples of the near 25-day period.
Starting ART following cryptococcal meningitis:The optimal time has yet to be defined
T A Bicanic; Jarvis, J. N.; A. Loyse; Harrison, T.S.
2013-01-01
Ever since the public sector rollout of antiretroviral therapy (ART) in 2004, the question of the optimal time to start ART following diagnosis of an opportunistic infection has aroused controversy among South African HIV clinicians and researchers.
Thompson-Lastad, Ariana; Yen, Irene H; Fleming, Mark D; Van Natta, Meredith; Rubin, Sara; Shim, Janet K; Burke, Nancy J
2017-08-01
In this paper, we delineate how staff of two complex care management (CCM) programs in urban safety net hospitals in the United States understand trauma. We seek to (1) describe how staff in CCM programs talk about trauma in their patients' lives; (2) discuss how trauma concepts allow staff to understand patients' symptoms, health-related behaviors, and responses to care as results of structural conditions; and (3) delineate the mismatch between long-term needs of patients with histories of trauma and the short-term interventions that CCM programs provide. Observation and interview data gathered between February 2015 and August 2016 indicate that CCM providers define trauma expansively to include individual experiences of violence such as childhood abuse and neglect or recent assault, traumatization in the course of accessing health care and structural violence. Though CCM staff implement elements of trauma-informed care, the short-term design of CCM programs puts pressure on the staff to titrate their efforts, moving patients towards graduation or discharge. Trauma concepts enable clinicians to name structural violence in clinically legitimate language. As such, trauma-informed care and structural competency approaches can complement each other. Copyright © 2017 Elsevier Ltd. All rights reserved.
Defining a Formal Semantics for Real-Time Test Specification with TTCN-31
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Diana Alina Serbanescu
2013-02-01
Full Text Available Real-time software is usually used in circumstances where safety is important and the margin for errors isnarrow. These kinds of systems have applicability in a broad band of domains as: automotive, avionics, airtraffic control, nuclear power stations, industrial control, etc. As the name denotes, the main feature of"real-time" applications is the criticality of their timeliness. Guaranteeing certain timeliness requiresappropriate testing. As manual testing is burdensome and error prone, automated testing techniques arerequired. Although the importance of having a standard environment for automatic testing is high, thetechnologies in this area are not sufficiently developed. This paper reviews the standardized testdescription language "Testing and Test Control Notation version 3 (TTCN-3" as a mean for real-timetesting and proposes extensions to enable real-time testing with TTCN-3. The aim is to provide a completetesting solution for automatic functional and real-time testing, built around this already standardizedtesting language. The solution includes an environment for designing and running the tests written in theextended language. As a proof of concept, test examples, designed using the enhanced TTCN-3, are mappedto real-time platform implementations and the timeliness of each implementation is analyzed.
Directory of Open Access Journals (Sweden)
N. Dadashzadeh
2013-09-01
Full Text Available Ultra-short pulse is a promising technology for achieving ultra-high data rate transmission which is required to follow the increased demand of data transport over an optical communication system. Therefore, the propagation of such type of pulses and the effects that it may suffer during its transmission through an optical waveguide has received a great deal of attention in the recent years. We provide an overview of recent theoretical developments in a numerical modeling of Maxwell's equations to analyze the propagation of short laser pulses in photonic structures. The process of short light pulse propagation through 2D periodic and quasi-periodic photonic structures is simulated based on Finite-Difference Time-Domain calculations of Maxwell’s equations.
Distributed Real-Time Emulation of Formally-Defined Patterns for Safe Medical Device Control
Sun, Mu; 10.4204/EPTCS.36.9
2010-01-01
Safety of medical devices and of their interoperation is an unresolved issue causing severe and sometimes deadly accidents for patients with shocking frequency. Formal methods, particularly in support of highly reusable and provably safe patterns which can be instantiated to many device instances can help in this regard. However, this still leaves open the issue of how to pass from their formal specifications in logical time to executable emulations that can interoperate in physical time with other devices and with simulations of patient and/or doctor behaviors. This work presents a specification-based methodology in which virtual emulation environments can be easily developed from formal specifications in Real-Time Maude, and can support interactions with other real devices and with simulation models. This general methodology is explained in detail and is illustrated with two concrete scenarios which are both instances of a common safe formal pattern: one scenario involves the interaction of a provably safe ...
Isaacson, Dylan; Ahmad, Tessnim; Metzler, Ian; Tzou, David T; Taguchi, Kazumi; Usawachintachit, Manint; Zetumer, Samuel; Sherer, Benjamin; Stoller, Marshall; Chi, Thomas
2017-09-20
Careful decontamination and sterilization of reusable flexible ureteroscopes used in ureterorenoscopy cases prevent the spread of infectious pathogens to patients and technicians. However, inefficient reprocessing and unavailability of ureteroscopes sent out for repair can contribute to expensive operating room (OR) delays. Time-driven activity-based costing (TDABC) was applied to describe the time and costs involved in reprocessing. Direct observation and timing were performed for all steps in reprocessing of reusable flexible ureteroscopes following operative procedures. Estimated times needed for each step by which damaged ureteroscopes identified during reprocessing are sent for repair were characterized through interviews with purchasing analyst staff. Process maps were created for reprocessing and repair detailing individual step times and their variances. Cost data for labor and disposables used were applied to calculate per minute and average step costs. Ten ureteroscopes were followed through reprocessing. Process mapping for ureteroscope reprocessing averaged 229.0 ± 74.4 minutes, whereas sending a ureteroscope for repair required an estimated 143 minutes per repair. Most steps demonstrated low variance between timed observations. Ureteroscope drying was the longest and highest variance step at 126.5 ± 55.7 minutes and was highly dependent on manual air flushing through the ureteroscope working channel and ureteroscope positioning in the drying cabinet. Total costs for reprocessing totaled $96.13 per episode, including the cost of labor and disposable items. Utilizing TDABC delineates the full spectrum of costs associated with ureteroscope reprocessing and identifies areas for process improvement to drive value-based care. At our institution, ureteroscope drying was one clearly identified target area. Implementing training in ureteroscope drying technique could save up to 2 hours per reprocessing event, potentially preventing expensive OR delays.
Unique Existence Theorem of Solution of Almost Periodic Differential Equations on Time Scales
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Meng Hu
2012-01-01
Full Text Available By using the theory of calculus on time scales and M-matrix theory, the unique existence theorem of solution of almost periodic differential equations on almost periodic time scales is established. The result can be used to a large of dynamic systems.
Unique Existence Theorem of Solution of Almost Periodic Differential Equations on Time Scales
Meng Hu; Lili Wang
2012-01-01
By using the theory of calculus on time scales and M-matrix theory, the unique existence theorem of solution of almost periodic differential equations on almost periodic time scales is established. The result can be used to a large of dynamic systems.
Starting ART following cryptococcal meningitis:The optimal time has yet to be defined
Directory of Open Access Journals (Sweden)
T A Bicanic
2013-09-01
Full Text Available Ever since the public sector rollout of antiretroviral therapy (ART in 2004, the question of the optimal time to start ART following diagnosis of an opportunistic infection has aroused controversy among South African HIV clinicians and researchers.
Time to insulin initiation can not be used in defining Latent Autoimmune Diabetes in Adults [LADA
DEFF Research Database (Denmark)
Brophy, S; Yderstræde, K; Mauricio, D;
2007-01-01
Objective: Latent Autoimmune Diabetes in Adults [LADA] is type 1 diabetes presenting as non-insulin dependent diabetes. One feature of the selection criteria is time independent of insulin treatment. We examine the validity of this criterion. Methods: Patients were recruited in 9 European centres...
Analytical Solutions of Time Periodic Electroosmotic Flow in a Semicircular Microchannel
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Shaowei Wang
2015-01-01
Full Text Available The time periodic electroosmotic flow of Newtonian fluids through a semicircular microchannel is studied under the Debye–Hückel approximation. Analytical series of solutions are found, and they consist of a time-dependent oscillating part and a time-dependent generating or transient part. Some new physical phenomena are found. The electroosmotic flow driven by an alternating electric field is not periodic in time, but quasi-periodic. There is a phase shift between voltage and flow, which is only dependent on the frequency of external electric field.
[Trends in leisure time physical activity practice in the 1995-2005 period in Girona].
Redondo, Ana; Subirana, Isaac; Ramos, Rafel; Solanas, Pascual; Sala, Joan; Masiá, Rafael; Schröder, Helmut; Marrugat, Jaume; Elosua, Roberto
2011-11-01
The aims of the study were: to describe the distribution of physical activity practice; to determine the prevalence and trends of sedentary lifestyle in the population aged 35 to 74 years of Girona in the 1995-2005 period; and to identify the variables associated to sedentary lifestyle at the population level. Data from three independent population-based cross-sectional studies undertaken in 1995 (n=1419), 2000 (n=2499), and 2005 (n=5628) were analyzed. Physical activity was measured using the Minnesota Leisure Time Physical Activity questionnaire. Sedentary lifestyle was defined as an energy expenditure in moderate physical activity (4-5.5 METs) sedentary lifestyle. The age-standardized prevalence of sedentary lifestyle was 53.8%, 39.5%, and 32.6% in 1995, 2000, and 2005 respectively. The prevalence of sedentary lifestyle has decreased especially in women older than 50 years living in the urban areas. An increase in light and moderate physical activity practice in men older than 50 years and in light physical activity practice in women older than 50 years was observed. Female gender, age, smoking and lower educational level were associated with a higher prevalence of sedentary lifestyle. Prevalence of sedentary lifestyle has decreased in the 1995-2005 period in Girona, especially in women, but is still high. Health promotion programs should include physical activity practice as a key element and should take into account gender and social inequalities. Copyright © 2011 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.
Korotkov, E. V.; Korotkova, M. A.
2017-01-01
The purpose of this study was to detect latent periodicity in the presence of deletions or insertions in the analyzed data, when the points of deletions or insertions are unknown. A mathematical method was developed to search for periodicity in the numerical series, using dynamic programming and random matrices. The developed method was applied to search for periodicity in the Euro/Dollar (Eu/) exchange rate, since 2001. The presence of periodicity within the period length equal to 24 h in the analyzed financial series was shown. Periodicity can be detected only with insertions and deletions. The results of this study show that periodicity phase shifts, depend on the observation time. The reasons for the existence of the periodicity in the financial ranks are discussed.
Prathap Reddy, K.
2016-11-01
An ‘electrostatic bathtub potential’ is defined and analytical expressions for the time period and amplitude of charged particles in this potential are obtained and compared with simulations. These kinds of potentials are encountered in linear electrostatic ion traps, where the potential along the axis appears like a bathtub. Ion traps are used in basic physics research and mass spectrometry to store ions; these stored ions make oscillatory motion within the confined volume of the trap. Usually these traps are designed and studied using ion optical software, but in this work the bathtub potential is reproduced by making two simple modifications to the harmonic oscillator potential. The addition of a linear ‘k 1|x|’ potential makes the simple harmonic potential curve steeper with a sharper turn at the origin, while the introduction of a finite-length zero potential region at the centre reproduces the flat region of the bathtub curve. This whole exercise of modelling a practical experimental situation in terms of a well-known simple physics problem may generate interest among readers.
Scattering analysis of periodic structures using finite-difference time-domain
ElMahgoub, Khaled; Elsherbeni, Atef Z
2012-01-01
Periodic structures are of great importance in electromagnetics due to their wide range of applications such as frequency selective surfaces (FSS), electromagnetic band gap (EBG) structures, periodic absorbers, meta-materials, and many others. The aim of this book is to develop efficient computational algorithms to analyze the scattering properties of various electromagnetic periodic structures using the finite-difference time-domain periodic boundary condition (FDTD/PBC) method. A new FDTD/PBC-based algorithm is introduced to analyze general skewed grid periodic structures while another algor
Energy Technology Data Exchange (ETDEWEB)
Huang Zhenkun [Department of Mathematics, School of Sciences, Zhejiang University, Hangzhou, Zhejiang 310027 (China) and School of Sciences, Jimei University, Xiamen, Fujian 361021 (China)]. E-mail: huangdoc@tom.com; Wang Xinghua [Department of Mathematics, School of Sciences, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Gao Feng [School of Sciences, Jimei University, Xiamen, Fujian 361021 (China)
2006-02-06
In this Letter, we discuss discrete-time analogue of a continuous-time cellular neural network. Sufficient conditions are obtained for the existence of a unique almost periodic sequence solution which is globally attractive. Our results demonstrate dynamics of the formulated discrete-time analogue as mathematical models for the continuous-time cellular neural network in almost periodic case. Finally, a computer simulation illustrates the suitability of our discrete-time analogue as numerical algorithms in simulating the continuous-time cellular neural network conveniently.
Institute of Scientific and Technical Information of China (English)
CHEN Wei-cheng; XU Wen-cheng
2006-01-01
Periodical polarization modulation scheme is proposed to suppress timing jitters induced by frequency fluctuations between two polarization components of solitons. In periodical polarization modulation scheme, the polarization states of the soliton are modulated to excite equally for suppressing timing jitters induced by two unequal polarization components in the soliton trapping. Moreover, polarization modulation can weaken the effect of random birefringence on the soliton pulses in each relay distance. The numerical result shows that the soliton timing jitters are suppressed by our proposed method.
Is it possible to define an optimal time for chemotherapy after surgery for ovarian cancer?
DEFF Research Database (Denmark)
Lydiksen, L; Christensen, Lisbeth Lydiksen; Jensen-Fangel, S
2014-01-01
OBJECTIVE: The aims of this study are to investigate the actual time from primary surgery for epithelial ovarian cancer (OC) to initiation of chemotherapy (TI) amongst Danish women in 2005-2006, and to compare the survival for groups with early initiation (≤median TI) and late initiation...... for death in patients with TI>32days compared with TI≤32days was 0.85 (95% CI: 0.70; 1.04), p-value 0.12. When adjusted for residual tumour and FIGO-stage the HR was 1.13 (95% CI: 0.92; 1.39), p-value 0.26. The overall five-year survival was 42.8%, (95% CI: 38.9%; 46.5%). CONCLUSIONS: This nationwide...... population-based cohort study revealed a non-significant increased risk of death for patients with TI>32days compared with the reference TI≤32days. The strongest prognostic factors were residual tumour after surgery and FIGO-stage. The overall five-year survival was 42.8% (95% CI: 38.9%; 46.5%)....
Yang, Hui; Zhang, Jie; Zhao, Yongli; Ji, Yuefeng; Li, Hui; Lin, Yi; Li, Gang; Han, Jianrui; Lee, Young; Ma, Teng
2014-07-28
Data center interconnection with elastic optical networks is a promising scenario to meet the high burstiness and high-bandwidth requirements of data center services. We previously implemented enhanced software defined networking over elastic optical network for data center application [Opt. Express 21, 26990 (2013)]. On the basis of it, this study extends to consider the time-aware data center service scheduling with elastic service time and service bandwidth according to the various time sensitivity requirements. A novel time-aware enhanced software defined networking (TeSDN) architecture for elastic data center optical interconnection has been proposed in this paper, by introducing a time-aware resources scheduling (TaRS) scheme. The TeSDN can accommodate the data center services with required QoS considering the time dimensionality, and enhance cross stratum optimization of application and elastic optical network stratums resources based on spectrum elasticity, application elasticity and time elasticity. The overall feasibility and efficiency of the proposed architecture is experimentally verified on our OpenFlow-based testbed. The performance of TaRS scheme under heavy traffic load scenario is also quantitatively evaluated based on TeSDN architecture in terms of blocking probability and resource occupation rate.
Stability and robustness analysis of a linear time-periodic system subjected to random perturbations
Redkar, Sangram; Liu, J.; Sinha, S. C.
2012-03-01
In this work, new methods of guaranteeing the stability of linear time periodic dynamical systems with stochastic perturbations are presented. In the approaches presented here, the Lyapunov-Floquet (L-F) transformation is applied first so that the linear time-periodic part of the equations becomes time-invariant. For the linear time periodic system with stochastic perturbations, a stability theorem and related corollary have been suggested using the results previously obtained by Infante. This technique is not only applicable to systems with stochastic parameters but also to systems with deterministic variation in parameters. Some illustrative examples are presented to show the practical applications. These methods can be used to investigate the degree of robustness and design controllers for systems with time periodic coefficients subjected to random perturbations.
Modal Vibration Control in Periodic Time-Varying Structures with Focus on Rotor-Blade Systems
DEFF Research Database (Denmark)
Christensen, Rene Hardam; Santos, Ilmar
2003-01-01
to be overcome. Among others it is necessary, that the control scheme is capable to cope with non-linear time-varying dynamical system behaviour. However, rotating at constant speed the mathematical model becomes periodic time-variant. In this framework the present paper gives a contribution to design procedures...... of active modal controllers. The main aim is to reduce vibrations in periodic time-varying structures. Special emphasis is given to vibration control of coupled bladed rotor systems. A state feedback modal control law is developed based on modal analysis in periodic time-varying structures. The first step...... is reformulated using complex mode theory. Next, a linear constant gain controller for the reformulated system is designed by linear control technique. Finally, this constant gain controller is transformed to a time-periodic form by applying reverse modal transformation. The non-measurable states are estimated...
DEFF Research Database (Denmark)
Simonsen, Poul Erik; Niemann, L.; Meyrowitsch, Dan Wolf
1997-01-01
pattern was observed. Mathematical analysis of the data indicated a peak at 0152 h and a periodicity index of 117.5. A periodicity equation was developed describing the average relation between mf intensity and hour of the day for the study area. Based on the observed periodicity pattern, the effect...... of blood sampling before peak time is discussed, and the importance of taking sampling time into consideration when analysing data from epidemiological studies is emphasized. A simple method is devised which can be used to adjust for the influence of time on mf intensities, in studies where accurate...
Period, epoch and prediction errors of ephemeris from continuous sets of timing measurements
Deeg, Hans J
2015-01-01
Space missions such as Kepler and CoRoT have led to large numbers of eclipse or transit measurements in nearly continuous time series. This paper shows how to obtain the period error in such measurements from a basic linear least-squares fit, and how to correctly derive the timing error in the prediction of future transit or eclipse events. Assuming strict periodicity, a formula for the period error of such time series is derived: sigma_P = sigma_T (12/( N^3-N))^0.5, where sigma_P is the period error; sigma_T the timing error of a single measurement and N the number of measurements. Relative to the iterative method for period error estimation by Mighell & Plavchan (2013), this much simpler formula leads to smaller period errors, whose correctness has been verified through simulations. For the prediction of times of future periodic events, the usual linear ephemeris where epoch errors are quoted for the first time measurement, are prone to overestimation of the error of that prediction. This may be avoided...
Time-periodic and stationary solutions to the compressible Hall-magnetohydrodynamic system
Cheng, Ming
2017-04-01
We are concerned with the 3-D compressible Hall-magnetohydrodynamic system with a time-periodic external force in a periodic domain, and establish the existence of a strong time-periodic solution under some smallness and symmetry assumptions by adapting a new approach. The basic idea of the proof is the following. First, we prove the existence of a time-periodic solution to the linearized system by applying the Tychonoff fixed point theorem combined with the energy method and the decay estimates. From the details of the proof, we see that the initial data of the time-periodic solution to the linearized system lies in some convex hull. Then, we construct a set-value function, such that the fixed point of this function is a time-periodic solution of the compressible Hall-magnetohydrodynamic system. The existence of the fixed point is obtained by the Kakutani fixed point theorem. Moreover, we establish the uniqueness of the time-periodic solution and the existence of the stationary solution.
Existence of Almost-Periodic Solutions for Lotka-Volterra Cooperative Systems with Time Delay
Directory of Open Access Journals (Sweden)
Kaihong Zhao
2012-01-01
Full Text Available This paper considers the existence of positive almost-periodic solutions for almost-periodic Lotka-Volterra cooperative system with time delay. By using Mawhin’s continuation theorem of coincidence degree theory, sufficient conditions for the existence of positive almost-periodic solutions are obtained. An example and its simulation figure are given to illustrate the effectiveness of our results.
Time courses of myofascial temporomandibular disorder complaints during a 12-month follow-up period
M.K.A. van Selms; F. Lobbezoo; M. Naeije
2009-01-01
AIMS: To investigate the time courses of myofascial temporomandibular disorder (TMD) pain and mandibular function impairment (MFI), and to identify predictive factors associated with these time courses. METHODS: During a 12-month period following conservative TMD treatment, the time courses of myofa
Positive Almost Periodic Solutions for a Time-Varying Fishing Model with Delay
Directory of Open Access Journals (Sweden)
Xia Li
2011-01-01
Full Text Available This paper is concerned with a time-varying fishing model with delay. By means of the continuation theorem of coincidence degree theory, we prove that it has at least one positive almost periodic solution.
Periodicity in a "Food-limited" Population Model with Toxicants and Time Delays
Institute of Scientific and Technical Information of China (English)
Meng Fan; Ke Wang
2002-01-01
With the help of a continuation theorem based on Gaines and Mawhin's coincidence degree, we study the global existence of positive periodic solutions of a "food-limited" population model with toxicants and time delays. Some new results are obtained.
Bayesian detection of periodic mRNA time profiles without use of training examples
Directory of Open Access Journals (Sweden)
Gustafsson Mats G
2006-02-01
Full Text Available Abstract Background Detection of periodically expressed genes from microarray data without use of known periodic and non-periodic training examples is an important problem, e.g. for identifying genes regulated by the cell-cycle in poorly characterised organisms. Commonly the investigator is only interested in genes expressed at a particular frequency that characterizes the process under study but this frequency is seldom exactly known. Previously proposed detector designs require access to labelled training examples and do not allow systematic incorporation of diffuse prior knowledge available about the period time. Results A learning-free Bayesian detector that does not rely on labelled training examples and allows incorporation of prior knowledge about the period time is introduced. It is shown to outperform two recently proposed alternative learning-free detectors on simulated data generated with models that are different from the one used for detector design. Results from applying the detector to mRNA expression time profiles from S. cerevisiae showsthat the genes detected as periodically expressed only contain a small fraction of the cell-cycle genes inferred from mutant phenotype. For example, when the probability of false alarm was equal to 7%, only 12% of the cell-cycle genes were detected. The genes detected as periodically expressed were found to have a statistically significant overrepresentation of known cell-cycle regulated sequence motifs. One known sequence motif and 18 putative motifs, previously not associated with periodic expression, were also over represented. Conclusion In comparison with recently proposed alternative learning-free detectors for periodic gene expression, Bayesian inference allows systematic incorporation of diffuse a priori knowledge about, e.g. the period time. This results in relative performance improvements due to increased robustness against errors in the underlying assumptions. Results from applying
Dynamical systems analysis of fluid transport in time-periodic vortex ring flows
Shariff, Karim; Leonard, Anthony; Ferziger, Joel H.
2006-01-01
It is known that the stable and unstable manifolds of dynamical systems theory provide a powerful tool for understanding Lagrangian aspects of time-periodic flows. In this work we consider two time-periodic vortex ring flows. The first is a vortex ring with an elliptical core. The manifolds provide information about entrainment and detrainment of irrotational fluid into and out of the volume transported with the ring. The likeness of the manifolds with features observed in flow visualization ...
Time perspective of the convicts of acquisitive crime in the initial period of serving the sentence
Directory of Open Access Journals (Sweden)
A. A. Martynova
2014-01-01
Full Text Available There were no statistically significant differences in the initial period of serving the sentence by all parameters of time perspective regardless of gender and the number of the previous records of acquisitive crime. A phenomenon of «perceptual distortion of course of life in the time continuum» was revealed. The degree of its manifestation affects the success of adaptation in the initial period of serving the sentence.
Some recent results on Schrödinger equations with time-periodic potentials
DEFF Research Database (Denmark)
Galtbayar, A.; Jensen, Arne; Yajima, K.
2004-01-01
We report on some recent results on Schrödinger equations with time-periodic potentials. The full report on the results will be published in Galtbayar, Jensen & Yajima, J. Statist Phys.......We report on some recent results on Schrödinger equations with time-periodic potentials. The full report on the results will be published in Galtbayar, Jensen & Yajima, J. Statist Phys....
Interfacial instability in a time-periodic rotating Hele-Shaw Cell
Directory of Open Access Journals (Sweden)
Bouchgl J.
2014-01-01
Full Text Available The effect of time-periodic angular velocity on the interfacial instability of two immiscible, viscous fluids of different densities and confined in an annular Hele-Shaw cell is investigated. An inviscid linear stability analysis of the viscous and time dependent basic flow leads to a periodic Mathieu oscillator describing the evolution of the interfacial amplitude. We show that the relevant parameters that control the interface are the Bond number, viscosity ratio, Atwood number and the frequency number.
DETERMINATION OF THE PERIOD OF A TORSION PENDULUM BY THE FITTING METHOD IN REAL TIME
Institute of Scientific and Technical Information of China (English)
无
1998-01-01
A phenomenological study on the fitting method in real time has been done, and the method was applied to process and analyze the extensive data of a long period torsion pendulum used to determine Newtonian gravitational constant G. The result shows that the fitting method in real time is effective to determine the period of a torsion pendulum with a relative precision of 10-5 orders.
Stability and periodicity of solutions for delay dynamic systems on time scales
Directory of Open Access Journals (Sweden)
Zhi-Qiang Zhu
2014-04-01
Full Text Available This article concerns the stability and periodicity of solutions to the delay dynamic system $$ x^{\\triangle}(t=A(t x(t + F(t, x(t, x(g(t+C(t $$ on a time scale. By the inequality technique for vectors, we obtain some stability criteria for the above system. Then, by using the Horn fixed point theorem, we present some conditions under which our system is asymptotically periodic and its periodic solution is unique. In particular, the periodic solution is positive under proper assumptions.
An infinite branching hierarchy of time-periodic solutions of the Benjamin-Ono equation
Energy Technology Data Exchange (ETDEWEB)
Wilkening, Jon
2008-07-01
We present a new representation of solutions of the Benjamin-Ono equation that are periodic in space and time. Up to an additive constant and a Galilean transformation, each of these solutions is a previously known, multi-periodic solution; however, the new representation unifies the subset of such solutions with a fixed spatial period and a continuously varying temporal period into a single network of smooth manifolds connected together by an infinite hierarchy of bifurcations. Our representation explicitly describes the evolution of the Fourier modes of the solution as well as the particle trajectories in a meromorphic representation of these solutions; therefore, we have also solved the problem of finding periodic solutions of the ordinary differential equation governing these particles, including a description of a bifurcation mechanism for adding or removing particles without destroying periodicity. We illustrate the types of bifurcation that occur with several examples, including degenerate bifurcations not predicted by linearization about traveling waves.
Directory of Open Access Journals (Sweden)
Matteo Gandetto
2004-09-01
Full Text Available The use of time-frequency distributions is proposed as a nonlinear signal processing technique that is combined with a pattern recognition approach to identify superimposed transmission modes in a reconfigurable wireless terminal based on software-defined radio techniques. In particular, a software-defined radio receiver is described aiming at the identification of two coexistent communication modes: frequency hopping code division multiple access and direct sequence code division multiple access. As a case study, two standards, based on the previous modes and operating in the same band (industrial, scientific, and medical, are considered: IEEE WLAN 802.11b (direct sequence and Bluetooth (frequency hopping. Neural classifiers are used to obtain identification results. A comparison between two different neural classifiers is made in terms of relative error frequency.
Estimating return periods of extreme values from relatively short time series of winds
Jonasson, Kristjan; Agustsson, Halfdan; Rognvaldsson, Olafur; Arfeuille, Gilles
2013-04-01
An important factor for determining the prospect of individual wind farm sites is the frequency of extreme winds at hub height. Here, extreme winds are defined as the value of the highest 10 minutes averaged wind speed with a 50 year return period, i.e. annual exceeding probability of 2% (Rodrigo, 2010). A frequently applied method to estimate winds in the lowest few hundred meters above ground is to extrapolate observed 10-meter winds logarithmically to higher altitudes. Recent study by Drechsel et al. (2012) showed however that this methodology is not as accurate as interpolating simulated results from the global ECMWF numerical weather prediction (NWP) model to the desired height. Observations of persistent low level jets near Colima in SW-Mexico also show that the logarithmic approach can give highly inaccurate results for some regions (Arfeuille et al., 2012). To address these shortcomings of limited, and/or poorly representative, observations and extrapolations of winds one can use NWP models to dynamically scale down relatively coarse resolution atmospheric analysis. In the case of limited computing resources one has typically to make a compromise between spatial resolution and the duration of the simulated period, both of which can limit the quality of the wind farm siting. A common method to estimate maximum winds is to fit an extreme value distribution (e.g. Gumbel, gev or Pareto) to the maximum values of each year of available data, or the tail of these values. If data are only available for a short period, e.g. 10 or 15 years, then this will give a rather inaccurate estimate. It is possible to deal with this problem by utilizing monthly or weekly maxima, but this introduces new problems: seasonal variation, autocorrelation of neighboring values, and increased discrepancy between data and fitted distribution. We introduce a new method to estimate return periods of extreme values of winds at hub height from relatively short time series of winds, simulated
DEFF Research Database (Denmark)
liu, weiwei; Wargocki, Pawel; Xiong, Jing
2014-01-01
The present work proposed a method to determine time period of thermal adaption of occupants in naturally ventilated building, based on the relationship between their neutral temperatures and running mean outdoor air temperature. Based on the data of the field investigation, the subjects’ time...
Modal Vibration Control in Periodic Time-Varying Structures with Focus on Rotor Blade Systems
DEFF Research Database (Denmark)
Christensen, Rene Hardam; Santos, Ilmar
2004-01-01
The demands for high efficiency machines initiate a demand for monitoring and active control of vibrations to improve machinery performance and to prolong machinery lifetime. Applying active control to reduce vibrations in flexible bladed rotor-systems imply that several difficulties have...... of active modal controllers. The main aim is to reduce vibrations in periodic time-varying structures. Special emphasis is given to vibration control of coupled bladed rotor systems. A state feedback modal control law is developed based on modal analysis in periodic time-varying structures. The first step...... to be overcome. Among others it is necessary, that the control scheme is capable to cope with non-linear time-varying dynamical system behaviour. However, rotating at constant speed the mathematical model becomes periodic time-variant. In this framework the present paper gives a contribution to design procedures...
Hu, Huicheng; Liu, JingJing; Yu, Jiaqi; Wang, Xuchun; Zheng, Haowen; Xu, Yong; Chen, Min; Han, Jie; Liu, Zhuang; Zhang, Qiao
2017-04-06
Janus nanostructures that possess two or more distinct components and surface functions have attracted more and more attention. Here, we present a seed-shape defined growth mechanism for the preparation of anisotropic Janus nanostructures, in which the shape of periodic mesoporous organosilica (PMO) is determined by the shape of Au nanoparticles. Various shaped Au@PMO composite nanostructures, such as rods, spheres, and plates, are prepared based on this general growth mechanism. By adjusting the reaction parameters (temperature, surfactant), various shaped AuNR@PMO Janus nanostructures, including horsebean- and fingernail-like nanostructures, have been successfully prepared. We also demonstrate the potential applications of such composite nanostructures. As an example, the as-prepared rod-like Janus Au@PMO nanostructures show great performance in chemo-photothermal combination therapy because of the excellent photothermal effect of Au nanorods and the high surface area of PMO nanorods. This research may open a new direction to the controllable synthesis and practical application of dedicated nanostructures with desired properties.
Almost Periodic Solution for Memristive Neural Networks with Time-Varying Delays
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Huaiqin Wu
2013-01-01
Full Text Available This paper is concerned with the dynamical stability analysis for almost periodic solution of memristive neural networks with time-varying delays. Under the framework of Filippov solutions, by applying the inequality analysis techniques, the existence and asymptotically almost periodic behavior of solutions are discussed. Based on the differential inclusions theory and Lyapunov functional approach, the stability issues of almost periodic solution are investigated, and a sufficient condition for the existence, uniqueness, and global exponential stability of the almost periodic solution is established. Moreover, as a special case, the condition which ensures the global exponential stability of a unique periodic solution is also presented for the considered memristive neural networks. Two examples are given to illustrate the validity of the theoretical results.
DEFF Research Database (Denmark)
Azhar, Hussain
This study looks at polarization and its components’ sensitivity to assumptions about equivalence scales, income definition, ethical income distribution parameters, and the income accounting period. A representative sample of Danish individual incomes from 1984 to 2002 is utilised. Results show...... that polarization has increased over time, regardless of the applied measure, when the last part of the period is compared to the first part of the period. Primary causes being increased inequality (alienation) and faster income growth among high incomes relative to those in the middle of the distribution....... Increasing the accounting period confirms the reduction in inequality found for shorter periods, but polarization is virtually unchanged, because income group identification increases. Applying different equivalence scales does not change polarization ranking for different years, but identification ranks...
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
In this paper, global exponential stability of almost periodic solution of cellular neural networks with time-varing delays (CNNVDs) is considered. By using the methods of the topological degree theory and generalized Halanay inequality, a few new applicable criteria are established for the existence and global exponential stability of almost periodic solution. Some previous results are improved and extended in this letter and one example is given to illustrate the effectiveness of the new results.
Dynamics of Periodic Waves in Bose-Einstein Condensate with Time-Dependent Atomic Scattering Length
Institute of Scientific and Technical Information of China (English)
LI Hua-Mei
2007-01-01
Evolution of periodic waves and solitary waves in Bose-Einstein condensates (BECs) with time-dependent atomic scattering length in an expulsive parabolic potential is studied. Based on the mapping deformation method, we successfully obtain periodic wave solutions and solitary wave solutions, including the bright and dark soliton solutions. The results in this paper include some in the literatures [Plys. Rev. Lett. 94 (2005) 050402 and Chin. Phys. Lett. 22(2005) 1855].
Rank One Strange Attractors in Periodically Kicked Predator-Prey System with Time-Delay
Yang, Wenjie; Lin, Yiping; Dai, Yunxian; Zhao, Huitao
2016-06-01
This paper is devoted to the study of the problem of rank one strange attractor in a periodically kicked predator-prey system with time-delay. Our discussion is based on the theory of rank one maps formulated by Wang and Young. Firstly, we develop the rank one chaotic theory to delayed systems. It is shown that strange attractors occur when the delayed system undergoes a Hopf bifurcation and encounters an external periodic force. Then we use the theory to the periodically kicked predator-prey system with delay, deriving the conditions for Hopf bifurcation and rank one chaos along with the results of numerical simulations.
Somfai, Tamás; Yoshioka, Koji; Tanihara, Fuminori; Kaneko, Hiroyuki; Noguchi, Junko; Kashiwazaki, Naomi; Nagai, Takashi; Kikuchi, Kazuhiro
2014-01-01
We report the successful piglet production from cryopreserved oocytes for the first time by using a simple, high capacity vitrification protocol for preservation and a defined system for in vitro embryo production. Immature cumulus-oocyte complexes (COCs) from prepubertal gilts were vitrified in microdrops and stored in liquid nitrogen. After warming, COCs were subjected to in vitro maturation (IVM), fertilization (IVF), and subsequent culture (IVC). Adjusting warmplate temperature to 42 °C during warming prevented temperature drops in a medium below 34.0 °C and significantly increased the percentage of oocyte survival and thus blastocyst yields obtained from total vitrified oocytes compared with that of warming at 38 °C (87.1% vs 66.9% and 4.4% vs 2.7%, respectively). Nuclear maturation and fertilization of oocytes were not affected by vitrification and warming temperature. Blastocyst development on day 7 (day 0 = IVF) of the surviving oocytes after warming at 38 °C and 42 °C was not different but lower (Pvitro using defined media. Using these modifications, live piglets could be obtained from cryopreserved oocytes for the first time.
Ulker, Fatma Demet
In forward flight, helicopter rotor blades function within a highly complex aerodynamic environment that includes both near-blade and far-blade aerodynamic phenomena. These aerodynamic phenomena cause fluctuating aerodynamic loads on the rotor blades. These loads when coupled with the dynamic characteristics and elastic motion of the blade create excessive amount of vibration. These vibrations degrade helicopter performance, passenger comfort and contributes to high cost maintenance problems. In an effort to suppress helicopter vibration, recent studies have developed active control strategies using active pitch links, flaps, twist actuation and higher harmonic control of the swash plate. In active helicopter vibration control, designing a controller in a computationally efficient way requires accurate reduced-order models of complex helicopter aeroelasticity. In previous studies, controllers were designed using aeroelastic models that were obtained by coupling independently reduced aerodynamic and structural dynamic models. Unfortunately, these controllers could not satisfy stability and performance criteria when implemented in high-fidelity computer simulations or real-time experiments. In this thesis, we present a novel approach that provides accurate time-periodic reduced-order models and time-periodic H2 and H infinity controllers that satisfy the stability and performance criteria. Computational efficiency and the necessity of using the approach were validated by implementing an actively controlled flap strategy. In this proposed approach, the reduced-order models were directly identified from high-fidelity coupled aeroelastic analysis by using the time-periodic subspace identification method. Time-periodic H2 and Hinfinity controllers that update the control actuation at every time step were designed. The control synthesis problem was solved using Linear Matrix Inequality and periodic Riccati Equation based formulations, for which an in-house periodic
Stellar evolution in real time: Period variations in galactic RR Lyr stars
Poretti, E; Vandenbroere, J; Paschke, A; Klotz, A; Boër, M; Damerdji, Y; Martignoni, M; Acerbi, F
2007-01-01
The times of maximum brightness collected in the GEOS RR Lyr database allowed us to trace the period variations of a sample of 123 galactic RRab variables. These data span a time baseline exceeding 100 years. Clear evidence of period increases or decreases at constant rates has been found, suggesting evolutionary effects. The observed rates are slightly larger than those predicted by theoretical models; moreover, there is an unexpected large percentage of RRab stars showing a period decrease. The new possibilities offered by the use of robotic telecopes (TAROTs, REM) and of data from satellite (CoRoT) are expected to speed up the project to measure stellar evolution in real time. It is noteworthy that the outlines of this project have been sketched during several GEOS meetings, where the different knowledge of amateur and professional astronomers found a very profitable synthesis.
Environmental input and cognitive growth: a study using time-period comparisons.
Huttenlocher, J; Levine, S; Vevea, J
1998-08-01
In this study, we examined the relation of input to cognitive growth in a single population of children. We studied 4 domains: Language, Spatial Operations, Concepts, and Associative Memory. Four groups of children drawn from the same population were tested in October of kindergarten, April of kindergarten, October of first grade, and April of first grade. These time points are 6 months apart, but they span periods that differ in amount of school input children receive. Much greater growth was found over time periods with greater amounts of school input (October to April) than over time periods with less school input (April to October) for Language, Spatial Operations, and Concepts, but not for Associative Memory. These findings suggest that amount of input is causally related to cognitive growth in particular domains.
Dynamics and Complexity in a Time Delay Model of RNA Silencing with Periodic Forcing
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Svetoslav Nikolov
2008-10-01
Full Text Available Simple periodic behavior and occurrence of complex oscillatory phenomena underlie of a large number of biochemical system models. In many cases the transition from stable to simple/complex oscillatory behavior can be connected with the appearance of abnormal process likes as cancer. In this paper we propose a time delay model of RNA silencing (also known as RNA interference with periodic forcing. In organisms with RNA silencing, each cell has a miniature "immune system" able to generate and amplify specific responses to a variety of gene transcripts. The consequences of a time delay on the dynamics of this model are analysed using Hopf's theorem. Our analytical calculations predict that time delay acts as a key bifurcation parameter. From the accomplished numerical results, it becomes clear that model has complexity oscillatory behavior when the amplitude of periodic force (i.e. the confusion in the target mRNA synthesis is large.
Directory of Open Access Journals (Sweden)
Anwesha Samanta
2015-09-01
Full Text Available The paper studies a periodic review inventory model with no shortages and different demand rates during pre- and post- deterioration periods . Deterioration of units start after a fixed time interval, and the deterioration rate is time dependent. The model determines the optimal reorder interval and the optimal order quantity so as to minimize the total cost per unit length of an inventory cycle. An extension of the model to include price discount has been further considered. Numerical examples are presented to illustrate the model and a sensitivity analysis is also reported.
A Time-Delayed Mathematical Model for Tumor Growth with the Effect of a Periodic Therapy
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Shihe Xu
2016-01-01
Full Text Available A time-delayed mathematical model for tumor growth with the effect of periodic therapy is studied. The establishment of the model is based on the reaction-diffusion dynamics and mass conservation law and is considered with a time delay in cell proliferation process. Sufficient conditions for the global stability of tumor free equilibrium are given. We also prove that if external concentration of nutrients is large the tumor will not disappear and the conditions under which there exist periodic solutions to the model are also determined. Results are illustrated by computer simulations.
Desai, Kush R; Laws, James L; Salem, Riad; Mouli, Samdeep K; Errea, Martin F; Karp, Jennifer K; Yang, Yihe; Ryu, Robert K; Lewandowski, Robert J
2017-06-01
Despite growth in placement of retrievable inferior vena cava filters, retrieval rates remain low. Filters with extended implantation times present a challenge to retrieval, where standard techniques often fail. The development of advanced retrieval techniques has positively impacted retrieval of retrievable inferior vena cava filters with prolonged dwell times; however, there is no precise definition of the time point when advanced techniques become necessary. We aim to define prolonged retrievable inferior vena cava filters dwell time by determining the inflection point when the risk of standard retrieval technique failure increases significantly, necessitating advanced retrieval techniques to maintain overall technical success of retrieval. From January 2009 to April 2015, 762 retrieval procedures were identified from a prospectively acquired database. We assessed patient age/sex, filter dwell time, procedural technical success, the use of advanced techniques, and procedure-related adverse events. Overall retrieval success rate was 98% (n=745). When standard retrieval techniques failed, advanced techniques were used; this was necessary 18% of the time (n=138). Logistic regression identified that dwell time was the only risk factor for failure of standard retrieval technique (odds ratio, 1.08; 95% confidence interval, 1.05-1.10; Ptechnique failure was 40.9%. Adverse events occurred at a rate of 2% (n=18; 15 minor and 3 major). The necessity of advanced techniques to maintain technical success of retrieval increases with dwell time. Patients with retrievable inferior vena cava filters in place beyond 7 months may benefit from referral to centers with expertise in advanced filter retrieval. © 2017 American Heart Association, Inc.
Ways of spending free time by alcohol addicts during periods of drinking and rehabilitation
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Dragišić-Labaš Slađana
2012-01-01
Full Text Available In the introduction we discuss free time in the context of consequences of alcoholism on social, psychological, and especially family life, then, the changing use of free time as a significant symptom of alcoholism, and finally, the new organization of free time as an important goal of social reintegration of alcoholics’ families. In the next section, we examine ways in which members of Skela Club at the “Dr Laza Lazarević” Psychiatric Hospital spend their free time during periods of drinking, and during rehabilitation and social integration. The sample consisted of 30 subjects (25 men and 5 women, aged between 25 and 65, living in Belgrade or nearby, regularly attending Club meetings and actively participating in its work. A questionnaire with 35 questions, 32 closed and 3 open, was used. The first part referred to socio-demographic variables, the second to ways of spending free time during the period of addiction, and the third part to free time at present, in the stage of abstinence and rehabilitation. During the period of drinking, subjects were mostly spending their free time in the company of other addicts, in 80% of cases. Their leisure was not very interesting, as it consisted of very few activities: sitting in a bar (76.6%, watching TV (53.3%, reading newspapers (50%, sleeping (40%. In the period of drinking a large number of subjects, regardless of gender, felt lonely - 83%. During the period of abstinence, on the contrary, leisure is better organized, the number of activities increases, and their model changes to socializing with friends (76.6%, communication with family members (66.6%, going for walks (60%, reading books (50%, listening to music (46.6%, and sport activities (36.6%. The conclusion is that alcohol addicts spent their free time during the period of drinking significantly differently than at present, when they are undergoing treatment and rehabilitation. The difference in the quality and organization of free time
Coding ill-defined and unknown cause of death is 13 times more frequent in Denmark than in Finland.
Ylijoki-Sørensen, Seija; Sajantila, Antti; Lalu, Kaisa; Bøggild, Henrik; Boldsen, Jesper Lier; Boel, Lene Warner Thorup
2014-11-01
Exact cause and manner of death determination improves legislative safety for the individual and for society and guides aspects of national public health. In the International Classification of Diseases, codes R00-R99 are used for "symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified" designated as "ill-defined" or "with unknown etiology". The World Health Organisation recommends avoiding the use of ill-defined and unknown causes of death in the death certificate as this terminology does not give any information concerning the possible conditions that led to the death. Thus, the aim of the study was, firstly, to analyse the frequencies of R00-R99-coded deaths in mortality statistics in Finland and in Denmark and, secondly, to compare these and the methods used to investigate the cause of death. To do so, we extracted a random 90% sample of the Finnish death certificates and 100% of the Danish certificates from the national mortality registries for 2000, 2005 and 2010. Subsequently, we analysed the frequencies of forensic and medical autopsies and external clinical examinations of the bodies in R00-R99-coded deaths. The use of R00-R99 codes was significantly higher in Denmark than in Finland; OR 18.6 (95% CI 15.3-22.4; pFinland, all of these deaths were investigated with a forensic autopsy. Our study suggests that if all deaths in all age groups with unclear cause of death were systematically investigated with a forensic autopsy, only 2-3/1000 deaths per year would be coded as an ill-defined and unknown cause of death in national mortality statistics. At the same time the risk to overlook unnatural deaths is decreased to a minimum. To achieve this in Denmark requires that the existing legislation on cause of death investigation would need to be changed to ensure that all deaths with unknown cause of death are investigated with a forensic autopsy.
Exact Feasibility Tests for Real-Time Scheduling of Periodic Tasks upon Multiprocessor Platforms
Cucu, Liliana
2008-01-01
In this paper we study the global scheduling of periodic task systems upon multiprocessor platforms. We first show two very general properties which are well-known for uniprocessor platforms and which remain for multiprocessor platforms: (i) under few and not so restrictive assumptions, we show that feasible schedules of periodic task systems are periodic from some point with a period equal to the least common multiple of task periods and (ii) for the specific case of synchronous periodic task systems, we show that feasible schedules repeat from the origin. We then present our main result: we characterize, for task-level fixed-priority schedulers and for asynchronous constrained or arbitrary deadline periodic task models, upper bounds of the first time instant where the schedule repeats. We show that job-level fixed-priority schedulers are predictable upon unrelated multiprocessor platforms. For task-level fixed-priority schedulers, based on the upper bounds and the predictability property, we provide for asy...
2T-PERIODIC SOLUTION FOR m ORDER NEUTRAL TYPE DIFFERENTIAL EQUATIONS WITH TIME DELAYS
Institute of Scientific and Technical Information of China (English)
张保生; 朱光辉
2002-01-01
Periodic solution of m order linear neutral equations with constant coefficient and time delays was studied. Existence and uniqueness of 2 T-periodic solutions for the equation were discussed by using the method of Fourier series. Some new necessary and sufficient conditions of existence and uniqueness of 2 T-periodic solutions for the equation are obtained. The main result is used widely. It contains results in some correlation paper for its special case, improves and extends the main results in them. Existence of periodic solution for the equation in larger number of particular case can be checked by using the result, but cannot be checked in another paper. In other words, the main result in this paper is most generalized for (1), the better result cannot be found by using the same method.
Energy Technology Data Exchange (ETDEWEB)
Skolski, J. Z. P., E-mail: j.z.p.skolski@utwente.nl; Vincenc Obona, J. [Materials innovation institute M2i, Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Römer, G. R. B. E.; Huis in ' t Veld, A. J. [Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)
2014-03-14
A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by “ablation after each laser pulse,” according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to “grow” either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.
Skolski, J. Z. P.; Römer, G. R. B. E.; Vincenc Obona, J.; Huis in't Veld, A. J.
2014-03-01
A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by "ablation after each laser pulse," according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to "grow" either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.
A Simple Discrete Model of Brownian Motors: Time-periodic Markov Chains
Ge, Hao; Jiang, Da-Quan; Qian, Min
2006-05-01
In this paper, we consider periodically inhomogeneous Markov chains, which can be regarded as a simple version of physical model—Brownian motors. We introduce for them the concepts of periodical reversibility, detailed balance, entropy production rate and circulation distribution. We prove the equivalence of the following statements: The time-periodic Markov chain is periodically reversible; It is in detailed balance; Kolmogorov's cycle condition is satisfied; Its entropy production rate vanishes; Every circuit and its reversed circuit have the same circulation weight. Hence, in our model of Markov chains, the directed transport phenomenon of Brownian motors, i.e. the existence of net circulation, can occur only in nonequilibrium and irreversible systems. Moreover, we verify the large deviation property and the Gallavotti-Cohen fluctuation theorem of sample entropy production rates of the Markov chain.
Inventory Model (Q, R) With Period of Grace, Quadratic Backorder Cost and Continuous Lead Time
Dr. Martin Osawaru Omorodion
2015-01-01
The paper considers the simple economic order model where the period of grace is operating, the lead time is continuous and the backorder cost is quadratic. The lead time follows a gamma distribution. The expected backorder cost per cycle is derived and averaged over all the states of the lead time L. Next we obtain the expected on hand inventory. The Lead time is taken as a Normal variate. The expected backorder costs are, derived after which the expected on hand inventory is derived. The...
Photovoltaic Generation Data Cleaning Method Based on Approximately Periodic Time Series
Zhang, J.; Zhang, Sh; Liang, J.; Tian, B.; Hou, Z.; Liu, B. Zh
2017-05-01
Data cleaning of photovoltaic (PV) power generation is an important step during data preprocessing for further utilization, such as PV power generation forecasting. The PV power generation data can be treated as a time series. An improved data cleaning method based on approximately periodic time series is proposed. First, the abnormal data in the PV data time series is classified with three types of the outliers. Then these three types of outliers are quantified based on the physical characters of PV power generation, and the effective corresponding cleaning implementations are described considering the rate capacity of PV station and period of PV data time series. Finally, the data cleaning method is tested on the PV generation data from a certain real power grid. The results show that this data cleaning method can effectively improve the PV data quality, and provide an effective support tool for the further application of PV data.
Necessary N-representability Constraints from Time-reversal Symmetry for Periodic Systems
Rubin, Nicholas C
2016-01-01
The variational calculation of the two-electron reduced density matrix (2-RDM) is extended to periodic molecular systems. If the 2-RDM theory is extended to the periodic case without consideration of time-reversal symmetry, however, it can yields energies that are significantly lower than the correct energies. We derive and implement linear constraints that enforce time-reversal symmetry on the 2-RDM without destroying its computationally favorable block-diagonal structure from translational invariance. Time-reversal symmetry is distinct from space-group or spin (SU(2)) symmetries which can be expressed by unitary transformations. The time-reversal symmetry constraints are demonstrated through calculations of the metallic hydrogen chain and the one-dimensional lithium hydride crystal.
Well-Posedness and averaging of NLS with time-periodic dispersion management
Antonelli, Paolo; Sparber, Christof
2012-01-01
We consider the Cauchy problem for dispersion managed nonlinear Schroedinger equations, where the dispersion map is assumed to be periodic and piecewise constant in time. We establish local and global well-posedness results and the possibility of finite time blow-up. In addition, we shall study the scaling limit of fast dispersion management and establish convergence to an effective model with averaged dispersion.
Kafka, K. R. P.; D. R. Austin; Li, H.; Yi, A; Cheng, J.; Chowdhury, E. A.
2015-01-01
Time-resolved diffraction microscopy technique has been used to observe the formation of laser-induced periodic surface structures (LIPSS) from the interaction of a single femtosecond laser pulse (pump) with a nano-scale groove mechanically formed on a single-crystal Cu substrate. The interaction dynamics (0-1200 ps) was captured by diffracting a time-delayed, frequency-doubled pulse from nascent LIPSS formation induced by the pump with an infinity-conjugate microscopy setup. The LIPSS ripple...
Periodic Solutions for a Class of Singular Hamiltonian Systems on Time Scales
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Xiaofang Meng
2014-01-01
Full Text Available We are concerned with a class of singular Hamiltonian systems on time scales. Some results on the existence of periodic solutions are obtained for the system under consideration by means of the variational methods and the critical point theory.
Almost Periodic Solutions to Dynamic Equations on Time Scales and Applications
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Yongkun Li
2012-01-01
equations on time scales. Then, as an application, using these concepts and results, we establish sufficient conditions for the existence and exponential stability of almost periodic solution to a class of Hopfield neural networks with delays. Finally, two examples and numerical simulations given to illustrate our results are plausible and meaningful.
Global stabilization of linear periodically time-varying switched systems via matrix inequalities
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
In this paper, we address the stabilization problem for linear periodically time-varying switched systems.Using discretization technique, we derive new conditions for the global stabilizability in terms of the solution of matrix inequalities. An algorithm for finding stabilizing controller and switching strategy is presented.
Almost periodic solution of shunting inhibitory cellular neural networks with time-varying delay
Energy Technology Data Exchange (ETDEWEB)
Huang Xia; Cao Jinde
2003-07-28
Several sufficient conditions are obtained for the existence of almost periodic solution and its attractivity of shunting inhibitory cellular neural networks with time-varying delay based on the fixed point method and Halanay inequality technique. Some previous results are improved and extended in this Letter and two examples are given to illustrate the effectiveness of the new results.
Periodic Solution to BAM-type Cohen-Grossberg Neural Network with Time-varying Delays
Institute of Scientific and Technical Information of China (English)
An-ping Chen; Qun-hua Gu
2011-01-01
By using the continuation theorem of Mawhin's coincidence degree theory and the Liapunov functional method, some sufficient conditions are obtained to ensure the existence, uniqueness and the global exponential stability of the periodic solution to the BAM-type Cohen-Grossberg neural networks involving time-varying delays.
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Xinggui Liu
2011-01-01
Full Text Available In this paper, by using Mawhin's continuation theorem of coincidence degree theory, we establish the existence of at least four positive periodic solutions for a discrete time Lotka-Volterra competitive system with harvesting terms. An example is given to illustrate the effectiveness of our results.
Institute of Scientific and Technical Information of China (English)
Yepeng Xing; Qiong Wang; Valery G. Romanovski
2009-01-01
We prove several new comparison results and develop the monotone iterative tech-nique to show the existence of extremal solutions to a kind of periodic boundary value problem (PBVP) for nonlinear integro-differential equation of mixed type on time scales.
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S. S. Mishra
2008-01-01
Full Text Available A probabilistic inventory model for conditional credit period with exponential demand, non-zero lead time and multiple storage facility has been developed. The behaviour of total expected cost (TEC has been examined and the use and application of the model is demonstrated with the help of a numerical example.
Mapping the dynamics of adverse drug reactions in subsequent time periods using INDSCAL
Rikken, F.; Kiers, H.A.L.; Vos, R.
1995-01-01
In this study we have focused on the problem of mapping the dynamics of co-word-matrices from subsequent time periods. Methods for mapping dynamics are important for following trends in research. We have explored the possibilities of a three way multidimensional scaling method, INDSCAL. We are espec
Directory of Open Access Journals (Sweden)
Tamás Somfai
Full Text Available We report the successful piglet production from cryopreserved oocytes for the first time by using a simple, high capacity vitrification protocol for preservation and a defined system for in vitro embryo production. Immature cumulus-oocyte complexes (COCs from prepubertal gilts were vitrified in microdrops and stored in liquid nitrogen. After warming, COCs were subjected to in vitro maturation (IVM, fertilization (IVF, and subsequent culture (IVC. Adjusting warmplate temperature to 42 °C during warming prevented temperature drops in a medium below 34.0 °C and significantly increased the percentage of oocyte survival and thus blastocyst yields obtained from total vitrified oocytes compared with that of warming at 38 °C (87.1% vs 66.9% and 4.4% vs 2.7%, respectively. Nuclear maturation and fertilization of oocytes were not affected by vitrification and warming temperature. Blastocyst development on day 7 (day 0 = IVF of the surviving oocytes after warming at 38 °C and 42 °C was not different but lower (P<0.05 than those of non-vitrified control oocytes (4.6%, 5.2% and 17.9%, respectively. However, blastocyst cell numbers in the control and vitrified groups were similar irrespective of warming temperature. Omitting porcine follicular fluid (pFF from IVM medium (POM did not affect maturation, fertilization and embryo development of vitrified-warmed oocytes. Transfer of blastocysts obtained on day 5 from vitrified oocytes matured either with or without pFF into 4 recipients (2 for each group resulted in 4 pregnancies and the delivery of a total of 18 piglets. In conclusion, optimization of warming temperature was a key factor for achieving high survival rates, and surviving oocytes could be utilized in vitro using defined media. Using these modifications, live piglets could be obtained from cryopreserved oocytes for the first time.
Tary, J. B.; Herrera, R. H.; van der Baan, M.
2014-01-01
Recent studies show that the frequency content of continuous passive recordings contains useful information for the study of hydraulic fracturing experiments as well as longstanding applications in volcano and global seismology. The short-time Fourier transform (STFT) is usually used to obtain the time-frequency representation of a seismic trace. Yet, this transform has two main disadvantages, namely its fixed time-frequency resolution and spectral leakage. Here, we describe two methods based on autoregressive (AR) models: the short-time autoregressive method (ST-AR) and the Kalman smoother (KS). These two methods allow for the AR coefficients to vary over time in order to follow time-varying frequency contents. The outcome of AR methods depends mainly on the number of AR coefficients. We use a robust approach to estimate the optimum order of the AR methods that best matches the spectral comparison between Fourier and AR spectra. Comparing the outcomes of the three methods on a synthetic signal, a long-period volcanic event, and microseismic data, we show that the STFT and both AR methods are able to track fast changes in frequency content. The STFT provides reasonable results even for noisy data using a simple and effective algorithm. The coefficients of the AR filter are defined at all time in the case of the KS. However, its better time resolution is slightly offset by a lower frequency resolution and its computational complexity. The ST-AR has a high spectral resolution and the lowest sensitivity to background noises, facilitating the identification of the various frequency components. The estimated AR coefficients can also be used to extract parts of the signal. The study of long-term phenomena, such as resonance frequencies, or transient events, such as long-period events, could help to gain further insight on reservoir deformation during hydraulic fracturing experiments as well as global or volcano seismological signals.
Looking for granulation and periodicity imprints in the sunspot time series
Lopes, Ilidio
2015-01-01
The sunspot activity is the end result of the cyclic destruction and regeneration of magnetic fields by the dynamo action. We propose a new method to analyze the daily sunspot areas data recorded since 1874. By computing the power spectral density of daily data series using the Mexican hat wavelet, we found a power spectrum with a well-defined shape, characterized by three features. The first term is the 22 yr solar magnetic cycle, estimated in our work to be of 18.43 yr. The second term is related to the daily volatility of sunspots. This term is most likely produced by the turbulent motions linked to the solar granulation. The last term corresponds to a periodic source associated with the solar magnetic activity, for which the maximum of power spectral density occurs at 22.67 days. This value is part of the 22-27 day periodicity region that shows an above-average intensity in the power spectra. The origin of this 22.67 day periodic process is not clearly identified, and there is a possibility that it can be...
THE VARYING LIGHT CURVE AND TIMINGS OF THE ULTRASHORT-PERIOD CONTACT BINARY KIC 9532219
Energy Technology Data Exchange (ETDEWEB)
Lee, Jae Woo; Hong, Kyeongsoo; Koo, Jae-Rim; Park, Jang-Ho, E-mail: jwlee@kasi.re.kr, E-mail: kshong@kasi.re.kr, E-mail: koojr@kasi.re.kr, E-mail: pooh107162@kasi.re.kr [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of)
2016-03-20
KIC 9532219 is a W UMa-type eclipsing binary with an orbital period of 0.1981549 days that is below the short-period limit (∼0.22 days) of the period distribution for contact binaries. The Kepler light curve of the system exhibits striking changes in both eclipse depths and light maxima. Applying third-body and spot effects, the light-curve synthesis indicates that the eclipsing pair is currently in a marginal contact stage with a mass ratio of q = 1.20, an orbital inclination of i = 66.°0, a temperature difference of T{sub 1}–T{sub 2} = 172 K, and a third light of l{sub 3} = 75.9%. To understand the light variations with time, we divided up the light curve into 312 segments and analyzed them separately. The results reveal that variation of eclipse depth is primarily caused by changing amounts of contamination due to the nearby star KIC 9532228 between the Kepler Quarters and that the variable O’Connell effect originates from the starspot activity on the less massive primary component. Based on our light-curve timings, a period study of KIC 9532219 indicates that the orbital period has varied as a combination of a downward parabola and a light-travel-time (LTT) effect due to a third body, which has a period of 1196 days and a minimum mass of 0.0892 M{sub ⊙} in an orbit of eccentricity 0.150. The parabolic variation could be a small part of a second LTT orbit due to a fourth component in a wider orbit, instead of either mass transfer or angular momentum loss.
Directory of Open Access Journals (Sweden)
Jon Pedersen
Full Text Available BACKGROUND: Child mortality estimates from complete birth histories from Demographic and Health Surveys (DHS surveys and similar surveys are a chief source of data used to track Millennium Development Goal 4, which aims for a reduction of under-five mortality by two-thirds between 1990 and 2015. Based on the expected sample sizes when the DHS program commenced, the estimates are usually based on 5-y time periods. Recent surveys have had larger sample sizes than early surveys, and here we aimed to explore the benefits of using shorter time periods than 5 y for estimation. We also explore the benefit of changing the estimation procedure from being based on years before the survey, i.e., measured with reference to the date of the interview for each woman, to being based on calendar years. METHODS AND FINDINGS: Jackknife variance estimation was used to calculate standard errors for 207 DHS surveys in order to explore to what extent the large samples in recent surveys can be used to produce estimates based on 1-, 2-, 3-, 4-, and 5-y periods. We also recalculated the estimates for the surveys into calendar-year-based estimates. We demonstrate that estimation for 1-y periods is indeed possible for many recent surveys. CONCLUSIONS: The reduction in bias achieved using 1-y periods and calendar-year-based estimation is worthwhile in some cases. In particular, it allows tracking of the effects of particular events such as droughts, epidemics, or conflict on child mortality in a way not possible with previous estimation procedures. Recommendations to use estimation for short time periods when possible and to use calendar-year-based estimation were adopted in the United Nations 2011 estimates of child mortality.
Kerr, Matthew; Johnston, Simon; Shannon, Ryan
2015-01-01
In a search for periodic variation in the arrival times of pulses from 151 young, energetic pulsars, we have identified seven cases of modulation consistent with one or two harmonics of a single fundamental with time-scale 0.5-1.5 yr. We use simulations to show that these modulations are statistically significant and of high quality (sinusoidal) even when contaminated by the strong stochastic timing noise common to young pulsars. Although planetary companions could induce such modulation, the large implied masses and 2:1 mean motion resonances challenge such an explanation. Instead, the modulation is likely to be intrinsic to the pulsar, arising from quasi-periodic switching between stable magnetospheric states, and we propose that precession of the neutron star may regulate this switching.
Estimating Periodic Software Rejuvenation Schedules under Discrete-Time Operation Circumstance
Iwamoto, Kazuki; Dohi, Tadashi; Kaio, Naoto
Software rejuvenation is a preventive and proactive solution that is particularly useful for counteracting the phenomenon of software aging. In this article, we consider periodic software rejuvenation models based on the expected cost per unit time in the steady state under discrete-time operation circumstance. By applying the discrete renewal reward processes, we describe the stochastic behavior of a telecommunication billing application with a degradation mode, and determine the optimal periodic software rejuvenation schedule minimizing the expected cost. Similar to the earlier work by the same authors, we develop a statistically non-parametric algorithm to estimate the optimal software rejuvenation schedule, by applying the discrete total time on test concept. Numerical examples are presented to estimate the optimal software rejuvenation schedules from the simulation data. We discuss the asymptotic behavior of estimators developed in this paper.
Energy Technology Data Exchange (ETDEWEB)
Post, Richard F
2017-10-03
A high-stiffness stabilizer/bearings for passive magnetic bearing systems is provide where the key to its operation resides in the fact that when the frequency of variation of the repelling forces of the periodic magnet array is large compared to the reciprocal of the growth time of the unstable motion, the rotating system will feel only the time-averaged value of the force. When the time-averaged value of the force is radially repelling by the choice of the geometry of the periodic magnet array, the Earnshaw-related unstable hit motion that would occur at zero rotational speed is suppressed when the system is rotating at operating speeds.
GNSS related periodic signals in coordinate time-series from Precise Point Positioning
Abraha, K. E.; Teferle, F. N.; Hunegnaw, A.; Dach, R.
2017-03-01
In Global Navigation Satellite System (GNSS) coordinate time-series unrecognized errors and unmodelled (periodic) effects may bias nonlinear motions induced by geophysical signals. Hence, understanding and mitigating these errors is vital to reducing biases and on revealing subtle geophysical signals. To assess the nature of periodic signals in coordinate time-series Precise Point Positioning (PPP) solutions for the period 2008-2015 are generated. The solutions consider Global Positioning System (GPS), GLObalnaya NAvigatsionnaya Sputnikovaya Sistema (GLONASS) or combined GPS+GLONASS (GNSS) observations. We assess the periodic signals of station coordinates computed using the combined International GNSS Service (IGS) and four of its Analysis Centers (ACs) products. Furthermore, we make use of different filtering methods to investigate the sources of the periodic signals. A faint fortnightly signal in our PPP solution based on Jet Propulsion Laboratory (JPL) products and the existence of an 8 d period for those ACs generating combined GPS+GLONASS products are the main features in the GPS-only solutions. The existence of the 8 d period in the GPS-only solution indicates that GPS orbits computed in a combined GNSS solution contain GLONASS-specific signals. The GLONASS-only solution shows highly elevated powers at the third draconitic harmonic (˜120 d period), at the 8 d period and its harmonics (4 d, 2.67 d) besides the well-known annual, semi-annual and other draconitic harmonics. We show that the GLONASS constellation gaps before December 2011 contribute to the power at some of the frequencies. However, the well-known fortnightly signal in GPS-only solutions is not discernible in the GLONASS-only solution. The combined GNSS solution contains periodic signals from both systems, with most of the powers being reduced when compared to the single-GNSS solutions. A 52 per cent reduction for the horizontal components and a 36 per cent reduction for the vertical component
Directory of Open Access Journals (Sweden)
J. Rodrigues Dias
2006-11-01
Full Text Available Systems with different lifetime distributions, associated with increasing, decreasing, constant, and bathtub-shaped hazard rates, are examined in this paper. It is assumed that a failure is only detected if systems are inspected. New approximate solutions for the inspection period and for the expected duration of hidden faults are presented, on the basis of the assumption that only periodic and perfect inspections are carried out. By minimizing total expected cost per unit of time, on the basis of numerical results and a range of comparisons, the conclusion is drawn that these new approximate solutions are extremely useful and simple to put into practice.
Storing quantum information in XXZ spin rings with periodically time-controlled interactions
Energy Technology Data Exchange (ETDEWEB)
Giampaolo, S M; Illuminati, F; Mazzarella, G [Dipartimento di Fisica ' E. R. Caianiello' , Universita di Salerno, INFM UdR di Salerno, INFN Sezione di Napoli, Gruppo Collegato di Salerno, Via S. Allende, 84081 Baronissi, SA (Italy)
2005-10-01
We introduce a general scheme to realize massive quantum memories in simple systems of interacting qubits. Such systems are described by spin rings with XXZ intersite couplings of suitably time-periodically controlled amplitudes. We show that initially localized excitations undergo perfect periodic revivals, allowing for the simultaneous storage of arbitrary sets of different local states. This novel approach to the problem of storing quantum information hints at a new way to control and suppress the effect of decoherence on a quantum computer realized in a system with nonvanishing interactions between the constituent qubits.
A General Approach to Time Periodic Incompressible Viscous Fluid Flow Problems
Geissert, Matthias; Hieber, Matthias; Nguyen, Thieu Huy
2016-06-01
This article develops a general approach to time periodic incompressible fluid flow problems and semilinear evolution equations. It yields, on the one hand, a unified approach to various classical problems in incompressible fluid flow and, on the other hand, gives new results for periodic solutions to the Navier-Stokes-Oseen flow, the Navier-Stokes flow past rotating obstacles, and, in the geophysical setting, for Ornstein-Uhlenbeck and various diffusion equations with rough coefficients. The method is based on a combination of interpolation and topological arguments, as well as on the smoothing properties of the linearized equation.
Hu, Jin; Wang, Jun
2015-06-01
In recent years, complex-valued recurrent neural networks have been developed and analysed in-depth in view of that they have good modelling performance for some applications involving complex-valued elements. In implementing continuous-time dynamical systems for simulation or computational purposes, it is quite necessary to utilize a discrete-time model which is an analogue of the continuous-time system. In this paper, we analyse a discrete-time complex-valued recurrent neural network model and obtain the sufficient conditions on its global exponential periodicity and exponential stability. Simulation results of several numerical examples are delineated to illustrate the theoretical results and an application on associative memory is also given.
Plasticity of the intrinsic period of the human circadian timing system.
Directory of Open Access Journals (Sweden)
Frank A J L Scheer
Full Text Available Human expeditions to Mars will require adaptation to the 24.65-h Martian solar day-night cycle (sol, which is outside the range of entrainment of the human circadian pacemaker under lighting intensities to which astronauts are typically exposed. Failure to entrain the circadian time-keeping system to the desired rest-activity cycle disturbs sleep and impairs cognitive function. Furthermore, differences between the intrinsic circadian period and Earth's 24-h light-dark cycle underlie human circadian rhythm sleep disorders, such as advanced sleep phase disorder and non-24-hour sleep-wake disorders. Therefore, first, we tested whether exposure to a model-based lighting regimen would entrain the human circadian pacemaker at a normal phase angle to the 24.65-h Martian sol and to the 23.5-h day length often required of astronauts during short duration space exploration. Second, we tested here whether such prior entrainment to non-24-h light-dark cycles would lead to subsequent modification of the intrinsic period of the human circadian timing system. Here we show that exposure to moderately bright light ( approximately 450 lux; approximately 1.2 W/m(2 for the second or first half of the scheduled wake episode is effective for entraining individuals to the 24.65-h Martian sol and a 23.5-h day length, respectively. Estimations of the circadian periods of plasma melatonin, plasma cortisol, and core body temperature rhythms collected under forced desynchrony protocols revealed that the intrinsic circadian period of the human circadian pacemaker was significantly longer following entrainment to the Martian sol as compared to following entrainment to the 23.5-h day. The latter finding of after-effects of entrainment reveals for the first time plasticity of the period of the human circadian timing system. Both findings have important implications for the treatment of circadian rhythm sleep disorders and human space exploration.
Complete Periodic Synchronization of Memristor-Based Neural Networks with Time-Varying Delays
Directory of Open Access Journals (Sweden)
Huaiqin Wu
2013-01-01
Full Text Available This paper investigates the complete periodic synchronization of memristor-based neural networks with time-varying delays. Firstly, under the framework of Filippov solutions, by using M-matrix theory and the Mawhin-like coincidence theorem in set-valued analysis, the existence of the periodic solution for the network system is proved. Secondly, complete periodic synchronization is considered for memristor-based neural networks. According to the state-dependent switching feature of the memristor, the error system is divided into four cases. Adaptive controller is designed such that the considered model can realize global asymptotical synchronization. Finally, an illustrative example is given to demonstrate the validity of the theoretical results.
Weijtjens, Wout; Lataire, John; Devriendt, Christof; Guillaume, Patrick
2014-12-01
Periodical loads, such as waves and rotating machinery, form a problem for operational modal analysis (OMA). In OMA only the vibrations of a structure of interest are measured and little to nothing is known about the loads causing these vibrations. Therefore, it is often assumed that all dynamics in the measured data are linked to the system of interest. Periodical loads defy this assumption as their periodical behavior is often visible within the measured vibrations. As a consequence most OMA techniques falsely associate the dynamics of the periodical load with the system of interest. Without additional information about the load, one is not able to correctly differentiate between structural dynamics and the dynamics of the load. In several applications, e.g. turbines and helicopters, it was observed that because of periodical loads one was unable to correctly identify one or multiple modes. Transmissibility based OMA (TOMA) is a completely different approach to OMA. By using transmissibility functions to estimate the structural dynamics of the system of interest, all influence of the load-spectrum can be eliminated. TOMA therefore allows to identify the modal parameters without being influenced by the presence of periodical loads, such as harmonics. One of the difficulties of TOMA is that the analyst is required to find two independent datasets, each associated with a different loading condition of the system of interest. This poses a dilemma for TOMA; how can an analyst identify two different loading conditions when little is known about the loads on the system? This paper tackles that problem by assuming that the loading conditions vary continuously over time, e.g. the changing wind directions. From this assumption TOMA is developed into a time-varying framework. This development allows TOMA to not only cope with the continuously changing loading conditions. The time-varying framework also enables the identification of the modal parameters from a single dataset
Moeeni, Hamid; Bonakdari, Hossein; Fatemi, Seyed Ehsan
2017-04-01
Because time series stationarization has a key role in stochastic modeling results, three methods are analyzed in this study. The methods are seasonal differencing, seasonal standardization and spectral analysis to eliminate the periodic effect on time series stationarity. First, six time series including 4 streamflow series and 2 water temperature series are stationarized. The stochastic term for these series obtained with ARIMA is subsequently modeled. For the analysis, 9228 models are introduced. It is observed that seasonal standardization and spectral analysis eliminate the periodic term completely, while seasonal differencing maintains seasonal correlation structures. The obtained results indicate that all three methods present acceptable performance overall. However, model accuracy in monthly streamflow prediction is higher with seasonal differencing than with the other two methods. Another advantage of seasonal differencing over the other methods is that the monthly streamflow is never estimated as negative. Standardization is the best method for predicting monthly water temperature although it is quite similar to seasonal differencing, while spectral analysis performed the weakest in all cases. It is concluded that for each monthly seasonal series, seasonal differencing is the best stationarization method in terms of periodic effect elimination. Moreover, the monthly water temperature is predicted with more accuracy than monthly streamflow. The criteria of the average stochastic term divided by the amplitude of the periodic term obtained for monthly streamflow and monthly water temperature were 0.19 and 0.30, 0.21 and 0.13, and 0.07 and 0.04 respectively. As a result, the periodic term is more dominant than the stochastic term for water temperature in the monthly water temperature series compared to streamflow series.
X-ray Pulsars in the Magellanic Clouds: Time Evolution of their Luminosities and Spin Periods
Yang, Jun; Laycock, Silas; Coe, Malcolm J.; Drake, Jeremy J.; Hong, JaeSub; Antoniou, Vallia; Zezas, Andreas; Ho, Wynn C. G.
2017-08-01
We have collected and analyzed the complete archive of XMM-Newton (116), Chandra (151), and RXTE (952) observations of the Small Magellanic Cloud (SMC), spanning 1997-2014. The resulting observational library provides a comprehensive view of the physical, temporal and statistical properties of the SMC pulsar population across the luminosity range of L_X= 10^{31.2}-10^{38} erg/s. From a sample of 65 pulsars we report 1654 individual pulsar detections, yielding 1393 pulse period measurements. Our pipeline generates a suite of products for each pulsar detection: spin period, flux, event list, high time-resolution light-curve, pulse-profile, periodogram, and X-ray spectrum. Combining all three satellites, we generated complete histories of the spin periods, pulse amplitudes, pulsed fractions and X-ray luminosities. Many of the pulsars show variations in pulse period due to the combination of orbital motion and accretion torques. Long-term spin-up/down trends are seen in 28/25 pulsars respectively, pointing to sustained transfer of mass and angular momentum to the neutron star on decadal timescales. The distributions of pulse detection and flux as functions of spin period provide interesting findings: mapping boundaries of accretion-driven X-ray luminosity, and showing that fast pulsars (Psearch for optical counterparts to X-ray sources in the local dwarf galaxy IC 10 to form a comparison sample for Magellanic Cloud X-ray pulsars.
Infrared Time Lags for the Periodic Quasar PG 1302-102
Jun, Hyunsung D; Graham, Matthew J; Djorgovski, S G; Mainzer, Amy; Cutri, Roc M; Drake, Andrew J; Mahabal, Ashish A
2015-01-01
The optical light curve of the quasar PG 1302-102 at $z = 0.278$ shows a strong, smooth 5.2 yr periodic signal, detectable over a period of $\\sim 20$ yr. Although the interpretation of this phenomenon is still uncertain, the most plausible mechanisms involve a binary system of two supermassive black holes with a subparsec separation. At this close separation, the nuclear black holes in PG 1302-102 will likely merge within $\\sim 10^{5}$ yr due to gravitational wave emission alone. Here we report the rest-frame near-infrared time lags for PG 1302-102. Compiling data from {\\it WISE} and {\\it Akari}, we confirm that the periodic behavior reported in the optical light curve from Graham et al. (2015) is reproduced at infrared wavelengths, with best-fit observed-frame 3.4 and $4.6 \\mu$m time lags of $(2219 \\pm 153, 2408 \\pm 148)$ days for a near face-on orientation of the torus, or $(4103\\pm 153, 4292 \\pm 148)$ days for an inclined system with relativistic Doppler boosting in effect. The periodicity in the infrared ...
Huang, Zhu
2015-03-01
The periodic unsteady natural convection flow and heat transfer in a square enclosure containing a concentric circular cylinder is numerically studied. The temperature of the inner circular cylinder fluctuates periodically with time at higher averaged value while the temperature of the enclosure keeps lower constant, and the natural convection is driven by the temperature difference. The two-dimensional natural convection is simulated with high accuracy temporal spectral method and local radial basis functions method. The Rayleigh number is studied in the range 103 ≤ Ra ≤ 106, the temperature pulsating period ranges from 0.01 to 100 and the temperature pulsating amplitudes are a = 0.5, 1.0 and 1.5. Numerical results reveal that the fluid flow and heat transfer is strongly dependent on the pulsating temperature of inner cylinder. Comparing with the steady state natural convection, the heat transfer is enhanced generally for the time-periodic unsteady natural convection, and the local maximum heat transfer rate is observed for Ra = 105 and 106. Moreover, the phenomenon of backward heat transfer is discussed quantitatively. Also, the influence of pulsating temperature on the unsteady fluid flow and heat transfer are discussed and analyzed.
An EOQ Model for Phase Inventory with Induced Demand and Periodic Cycle Time
Directory of Open Access Journals (Sweden)
Sujit Kumar De
2014-01-01
Full Text Available This paper deals with a stock flow of an inventory problem over induced demand. The inventory is consumed through “core customer” or chain marketing system in an induced environment (inductance to exhaust all the items of the stock inventory in an indefinite time. The demand rate is depicted due to induced factor which is generated from the same inventory presented nearby. The inventory cycle time is split into several periodic times due to oscillatory feature of the inventory which is called phase inventory. Considering uniform demand, this cycle time splits into two basic parts, namely, “first shift” (phase and “second shift” (phase. Since the process dampens over time, so the whole inventory will exhaust after few periods. A cost function consisted of inventory cost, setup cost, and loss for induced items is minimized to obtain optimal order quantity and replenishment time. The multivariate lagrange interpolation (MLI over the average values of the postsensitivity analysis is developed here. Finally, graphical illustrations are made to justify the model.
Pseudo-periodic surrogate test to sample time series in stochastic softening Duffing oscillator
Energy Technology Data Exchange (ETDEWEB)
Gan Chunbiao [Department of Mechanics, CMEE, Zhejiang University, Hangzhou 310027 (China)]. E-mail: cb_gan@zju.edu.cn
2006-09-11
Identification of typical noise-contaminated sample response is a hard task in a nonlinear system under stochastic background since irregularity of the sample response may come from measure noise, dynamical noise, or nonlinear effect, etc., and conventional dynamical methods are generally not useful. Here, the pseudo-periodic surrogate algorithm by Small is employed to test the sample time series in the softening Duffing oscillator under the Gaussian white noise excitation. The correlation dimensions of the noisy periodic and the noise-induced chaotic time series of the system are compared with those of their corresponding surrogate data respectively, the leading Lyapunov exponents by Rosenstein's algorithm are also presented for comparison.
Application of predictive control scheduling method to real-time periodic control tasks overrun
Institute of Scientific and Technical Information of China (English)
SHEN Qing; GUI Wei-hua; YANG Chun-hua; YANG Tie-jun
2007-01-01
Based on the abort strategy of fixed periods, a novel predictive control scheduling methodology was proposed to efficiently solve overrun problems. By applying the latest control value in the prediction sequences to the control objective, the new strategy was expected to optimize the control system for better performance and yet guarantee the schedulability of all tasks under overrun. The schedulability of the real-time systems with p-period overruns was analyzed, and the corresponding stability criteria was given as well. The simulation results show that the new approach can improve the performance of control system compared to that of conventional abort strategy, it can reduce the overshoot and adjust time as well as ensure the schedulability and stability.
Tracing temperature in a nanometer size region in a picosecond time period.
Nakajima, Kaoru; Kitayama, Takumi; Hayashi, Hiroaki; Matsuda, Makoto; Sataka, Masao; Tsujimoto, Masahiko; Toulemonde, Marcel; Bouffard, Serge; Kimura, Kenji
2015-08-21
Irradiation of materials with either swift heavy ions or slow highly charged ions leads to ultrafast heating on a timescale of several picosecond in a region of several nanometer. This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies. These nanostructures are believed to be formed when the local temperature rises beyond the melting or boiling point of the material. Conventional techniques, however, are not applicable to measure temperature in such a localized region in a short time period. Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position. The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model.
Directory of Open Access Journals (Sweden)
Özlem Acar
2016-01-01
Full Text Available OBJECTIVE: The aim of this study was to determine whether different rinsing time periods affected the wettability of polymerized elastomeric impression materials. MATERIALS AND METHOD: Panasil Contact Plus (PCP, Panasil Contact Non-Surfactant (PCNS, Panasil Initial Contact (PIC, Express (EXP and Impregum (IMP impression materials were tested. Standardized samples were rinsed with water for 10 s, 15 s or 20 s, and the wettability was determined by contact angle measurement through an evaluation period of 60 seconds (n=7. Non-rinsed groups were used as control. Measurements were made at 5 time points (at 0, 6, 15, 30 and 60 seconds. Kruskal Wallis test and Conover’s multiple comparison tests were used for all multiple comparisons. Bonferroni adjustment was applied for controlling Type I error (p0.002. CONCLUSION: Rinsing the surfactant-containing polyvinylsiloxane impression materials decreased their wettability, whereas no such effect was seen for the surfactant free polyvinylsiloxane and polyether impression materials.
Time functions of deep earthquakes from broadband and short-period stacks
Houston, H.; Benz, H.M.; Vidale, J.E.
1998-01-01
To constrain dynamic source properties of deep earthquakes, we have systematically constructed broadband time functions of deep earthquakes by stacking and scaling teleseismic P waves from U.S. National Seismic Network, TERRAscope, and Berkeley Digital Seismic Network broadband stations. We examined 42 earthquakes with depths from 100 to 660 km that occurred between July 1, 1992 and July 31, 1995. To directly compare time functions, or to group them by size, depth, or region, it is essential to scale them to remove the effect of moment, which varies by more than 3 orders of magnitude for these events. For each event we also computed short-period stacks of P waves recorded by west coast regional arrays. The comparison of broadband with short-period stacks yields a considerable advantage, enabling more reliable measurement of event duration. A more accurate estimate of the duration better constrains the scaling procedure to remove the effect of moment, producing scaled time functions with both correct timing and amplitude. We find only subtle differences in the broadband time-function shape with moment, indicating successful scaling and minimal effects of attenuation at the periods considered here. The average shape of the envelopes of the short-period stacks is very similar to the average broadband time function. The main variations seen with depth are (1) a mild decrease in duration with increasing depth, (2) greater asymmetry in the time functions of intermediate events compared to deep ones, and (3) unexpected complexity and late moment release for events between 350 and 550 km, with seven of the eight events in that depth interval displaying markedly more complicated time functions with more moment release late in the rupture than most events above or below. The first two results are broadly consistent with our previous studies, while the third is reported here for the first time. The greater complexity between 350 and 550 km suggests greater heterogeneity in
A Coupled Far-Field Formulation for Time-Periodic Numerical Problems in Fluid Dynamics
Indian Academy of Sciences (India)
Edmund Chadwick; Rabea El-Mazuzi
2012-11-01
Consider uniform flow past an oscillating body generating a time-periodic motion in an exterior domain, modelled by a numerical fluid dynamics solver in the near field around the body. A far-field formulation, based on the Oseen equations, is presented for coupling onto this domain thereby enabling the whole space to be modelled. In particular, examples for formulations by boundary elements and infinite elements are described.
Timing of millennial-scale climate change in Antarctica and Greenland during the last glacial period
DEFF Research Database (Denmark)
Blunier, T; Brook, E J
2001-01-01
A precise relative chronology for Greenland and West Antarctic paleotemperature is extended to 90,000 years ago, based on correlation of atmospheric methane records from the Greenland Ice Sheet Project 2 and Byrd ice cores. Over this period, the onset of seven major millennial-scale warmings....... This pattern provides further evidence for the operation of a "bipolar see-saw" in air temperatures and an oceanic teleconnection between the hemispheres on millennial time scales....
Lenart, Łukasz
2011-01-01
The aim of this article is to establish asymptotic distributions and consistency of subsampling for spectral density and for magnitude of coherence for non-stationary, almost periodically correlated time series. We show the asymptotic normality of the spectral density estimator and the limiting distribution of a magnitude of coherence statistic for all points from the bifrequency square. The theoretical results hold under $\\alpha$-mixing and moment conditions.
Asymptotic Weighted-Periodicity of the Impulsive Parabolic Equation with Time Delay
Institute of Scientific and Technical Information of China (English)
Jin-liang Wang; Hui-feng Li
2007-01-01
The main aim of this paper is to investigate the effects of the impulse and time delay on a type of parabolic equations. In view of the characteristics of the equation, a particular iteration scheme is adopted.The results show that Under certain conditions on the coefficients of the equation and the impulse, the solution oscillates in a particular manner-called "asymptotic weighted-periodicity".
Carvalho Filho,José Luiz S de; Arie F Blank; Péricles B. Alves; Polyana A.D. Ehlert; Alberto S. de Melo; Sócrates C. H. Cavalcanti; Arrigoni-Blank, Maria de Fátima; Silva-Mann,Renata
2006-01-01
Ocimum basilicum L. essential oil with high concentration of linalool is valuable in international business. O. basilicum essential oil is widely used as seasoning and in cosmetic industry. To assure proper essential oil yield and quality, it is crucial to determine which environmental and processing factors are affecting its composition. The goal of our work is to evaluate the effects of harvesting time, temperature, and drying period on the yield and chemical composition of O. basilicum ess...
Electron Transport in Graphene-Based Double-Barrier Structure under a Time Periodic Field
Institute of Scientific and Technical Information of China (English)
LU Wei-Tao; WANG Shun-Jin
2011-01-01
The transport property of electron through graphene-based double-barrier under a time periodic field is investigated. We study the influence of the system parameters and external field strength on the transmission probability.The results show that transmission exhibits various kinds of behavior with the change of parameters due to its angular anisotropy. One could control the values of transmission and conductivity as well as their distribution in each band by tuning the parameters.
Effects of weak periodic pressure waves on time to ignition of fuel mixtures
Vainshtein, P.; Gutfinger, C.
2001-09-01
The accumulation of small-amplitude gas dynamic perturbations accelerates the process of self-ignition of a homogeneous explosive mixture. In the present paper the cumulative effect of forced acoustic oscillations is studied when timescales of piston motions in a closed cylinder are comparable with the acoustic timescale. It is shown that the most significant shortening of the time to ignition takes place in a resonant system, where periodic shock waves travel back and forth in the cylinder.
Zhang, Shangbin; Lu, Siliang; He, Qingbo; Kong, Fanrang
2016-09-01
For rotating machines, the defective faults of bearings generally are represented as periodic transient impulses in acquired signals. The extraction of transient features from signals has been a key issue for fault diagnosis. However, the background noise reduces identification performance of periodic faults in practice. This paper proposes a time-varying singular value decomposition (TSVD) method to enhance the identification of periodic faults. The proposed method is inspired by the sliding window method. By applying singular value decomposition (SVD) to the signal under a sliding window, we can obtain a time-varying singular value matrix (TSVM). Each column in the TSVM is occupied by the singular values of the corresponding sliding window, and each row represents the intrinsic structure of the raw signal, namely time-singular-value-sequence (TSVS). Theoretical and experimental analyses show that the frequency of TSVS is exactly twice that of the corresponding intrinsic structure. Moreover, the signal-to-noise ratio (SNR) of TSVS is improved significantly in comparison with the raw signal. The proposed method takes advantages of the TSVS in noise suppression and feature extraction to enhance fault frequency for diagnosis. The effectiveness of the TSVD is verified by means of simulation studies and applications to diagnosis of bearing faults. Results indicate that the proposed method is superior to traditional methods for bearing fault diagnosis.
Modeling the time-periodicity of in-degree distributions in scientific citation networks
Liu, Qi; Xie, Zonglin; Dong, Enming; Li, Jianping
2016-01-01
In a range of citation networks, the in-degree distributions boast time-periodicity---the distributions of citations per article published each year present similar scale-free tails. This phenomenon can be regarded as a consequence of the emergence of hot topics and the existence of the "burst" phenomenon. With this inference considered, a geometric model based on our previous study is established, in which the sizes of the influence zones of nodes follow the same power-law distribution and decrease with their ages. The model successfully reproduces the time-periodicity of the in-degree distributions of the empirical data, and accounts for the presence of citation burst as well. Moreover, a reasonable explanation for the emergence of the scale-free tails by regarding the citation behavior between articles as a "yes/no" experiment is presented. The model can also predict the time-periodicity of the local clustering coefficients, which indicates that the model is a good tool in researches on the evolutionary me...
MULTI BAND INSAR ANALYSIS OF SUBSIDENCE DEVELOPMENT BASED ON THE LONG PERIOD TIME SERIES
2015-01-01
The SAR Interferometry (InSAR) application has shown great potential in monitoring of land terrain changes and in detection of land deformations such as subsidence. Longer time analysis can lead to understand longer trends and changes. Using different bands of SAR satellite (C- from ERS 1-2 and Envisat, L- from ALOS) over the study area, we achieve knowledge of movements in long-term and evaluation of its dynamic changes within observed period of time. Results from InSAR processing fit with t...
Umesh, Mahantshetty; Kumar, Deepak P; Chadha, Pranav; Choudary, Rajiv; Kembhavi, Seema; Thakur, Meenakshi; Reena, Engineer; Chopra, Supriya; Shrivastava, Shyamkishore
2017-01-01
Advanced radiotherapy techniques have emphasized on the importance of accurate target volume localization and delineation. The aim of this study was to determine time taken to achieve moderate bladder volume under physiological conditions, using transabdominal ultrasound. Patients with cervical cancer undergoing radical radiation with or without concomitant chemotherapy underwent serial ultrasound to estimate bladder filling. With a strict bladder protocol of consuming 1000 mL of water orally over 30 minutes after emptying the bladder, ultrasound was done after 45 minutes from bladder emptying time and repeated at 15-minute interval till 300 (25) mL filling was achieved and repeated every week. Forty-six patients with weekly ultrasound for bladder-filling documentation were evaluated. The mean (standard deviation) bladder volume measured at 45 minutes was 220 (93), 210 (95), 195 (91), 195 (96), and 190 (85) mL (average: 200; median: 195 mL) for the first to fifth week, respectively, and the mean (standard deviation) volume at 75 minutes was 300 (95), 310 (80), 290 (80), 295 (80), and 285 (70) mL (average: 295; median: 300 mL). The mean (standard deviation) time for bladder filling to 300 mL in the first, second, third, fourth, and fifth week was 57 ( 13.5), 67 (16.6), 66 (16.7), 66 (15.5), and 69 (17.1) minutes, respectively. Bladder filling to a definitive moderate volume at a reasonably fixed time period in each week of radiation is well tolerated, feasible, and measurable by weekly transabdominal ultrasound measurements.
EFFECT OF MAGNETIZATION OF WATER ON INDUCTION TIME AND GROWTH PERIOD OF NATURAL GAS HYDRATE
Institute of Scientific and Technical Information of China (English)
KUANG Li; FAN Shuanshi
2003-01-01
The effect of diluted solution's magnetization on induction time and growth period of natural gas hydrate (NGH) has been investigated in quiescent reaction system at pressure of 4. 5 MPa and temperature of 274 K with SDS as surfactant, by using volume fixed and pressure falling method. Experimental results show that magnetization will have effect on the induction time of NGH. After magnetization with magnetic field intensity of 0.33 T, the induction time of NGH has been reduced to 47 min (average) from 99 min (average) in which there is no magnetization. On the other hand, the induction time has been prolonged after magnetization of the diluted solution with magnetic field intensity of 0.05 T, 0. 11 T, 0.22 T, 0.44T. Especially with magnetic field intensity of 0.11 T, the induction time had even been prolonged to 431min (average). The effect of magnetization on the growth period of NGH has not been found at the experimental condition.
Theoretical Considerations on the Computation of Generalized Time-Periodic Waves
Pauly, Dirk
2011-01-01
We present both, theory and an algorithm for solving time-harmonic wave problems in a general setting. The time-harmonic solutions will be achieved by computing time-periodic solutions of the original wave equations. Thus, an exact controllability technique is proposed to solve the time-dependent wave equations. We discuss a first order Maxwell type system, which will be formulated in the framework of alternating differential forms. This enables us to investigate different kinds of classical wave problems in one fell swoop, such as acoustic, electro-magnetic or elastic wave problems. After a sufficient theory is established, we formulate our exact controllability problem and suggest a least-squares optimization procedure for its solution, which itself is solved in a natural way by a conjugate gradient algorithm operating in the canonical Hilbert space. Therefore, it might be one of the biggest advances of this approach that the proposed conjugate gradient algorithm does not need any preconditioning.
A Real-Time Capable Software-Defined Receiver Using GPU for Adaptive Anti-Jam GPS Sensors
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Dennis Akos
2011-09-01
Full Text Available Due to their weak received signal power, Global Positioning System (GPS signals are vulnerable to radio frequency interference. Adaptive beam and null steering of the gain pattern of a GPS antenna array can significantly increase the resistance of GPS sensors to signal interference and jamming. Since adaptive array processing requires intensive computational power, beamsteering GPS receivers were usually implemented using hardware such as field-programmable gate arrays (FPGAs. However, a software implementation using general-purpose processors is much more desirable because of its flexibility and cost effectiveness. This paper presents a GPS software-defined radio (SDR with adaptive beamsteering capability for anti-jam applications. The GPS SDR design is based on an optimized desktop parallel processing architecture using a quad-core Central Processing Unit (CPU coupled with a new generation Graphics Processing Unit (GPU having massively parallel processors. This GPS SDR demonstrates sufficient computational capability to support a four-element antenna array and future GPS L5 signal processing in real time. After providing the details of our design and optimization schemes for future GPU-based GPS SDR developments, the jamming resistance of our GPS SDR under synthetic wideband jamming is presented. Since the GPS SDR uses commercial-off-the-shelf hardware and processors, it can be easily adopted in civil GPS applications requiring anti-jam capabilities.
A real-time capable software-defined receiver using GPU for adaptive anti-jam GPS sensors.
Seo, Jiwon; Chen, Yu-Hsuan; De Lorenzo, David S; Lo, Sherman; Enge, Per; Akos, Dennis; Lee, Jiyun
2011-01-01
Due to their weak received signal power, Global Positioning System (GPS) signals are vulnerable to radio frequency interference. Adaptive beam and null steering of the gain pattern of a GPS antenna array can significantly increase the resistance of GPS sensors to signal interference and jamming. Since adaptive array processing requires intensive computational power, beamsteering GPS receivers were usually implemented using hardware such as field-programmable gate arrays (FPGAs). However, a software implementation using general-purpose processors is much more desirable because of its flexibility and cost effectiveness. This paper presents a GPS software-defined radio (SDR) with adaptive beamsteering capability for anti-jam applications. The GPS SDR design is based on an optimized desktop parallel processing architecture using a quad-core Central Processing Unit (CPU) coupled with a new generation Graphics Processing Unit (GPU) having massively parallel processors. This GPS SDR demonstrates sufficient computational capability to support a four-element antenna array and future GPS L5 signal processing in real time. After providing the details of our design and optimization schemes for future GPU-based GPS SDR developments, the jamming resistance of our GPS SDR under synthetic wideband jamming is presented. Since the GPS SDR uses commercial-off-the-shelf hardware and processors, it can be easily adopted in civil GPS applications requiring anti-jam capabilities.
Thaker, Nikhil G; Orio, Peter F; Potters, Louis
Magnetic resonance imaging (MRI) simulation and planning for prostate brachytherapy (PBT) may deliver potential clinical benefits but at an unknown cost to the provider and healthcare system. Time-driven activity-based costing (TDABC) is an innovative bottom-up costing tool in healthcare that can be used to measure the actual consumption of resources required over the full cycle of care. TDABC analysis was conducted to compare patient-level costs for an MRI-based versus traditional PBT workflow. TDABC cost was only 1% higher for the MRI-based workflow, and utilization of MRI allowed for cost shifting from other imaging modalities, such as CT and ultrasound, to MRI during the PBT process. Future initiatives will be required to follow the costs of care over longer periods of time to determine if improvements in outcomes and toxicities with an MRI-based approach lead to lower resource utilization and spending over the long-term. Understanding provider costs will become important as healthcare reform transitions to value-based purchasing and other alternative payment models. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
Institute of Scientific and Technical Information of China (English)
Du Lu-Chun; Mei Dong-Cheng
2009-01-01
Stochastic resonance (SR) of a periodically driven time-delayed linear system with multiplicative white noise and periodically modulated additive white noise is investigated. In the condition of small delay time, an approximate analytical expression of output signal-to-noise ratio (SNR) is obtained. The analytical results indicate that (1) there exists a resonance peak in the curve for SNR versus time delay; (2) the time delay will suspend the SR dramatically for SNR versus other parameters of the system, such as noise intensity, correlation intensity, and signal frequency, once a certain value is reached, the SR phenomenon disappears.
Detection of faults in rotating machinery using periodic time-frequency sparsity
Ding, Yin; He, Wangpeng; Chen, Binqiang; Zi, Yanyang; Selesnick, Ivan W.
2016-11-01
This paper addresses the problem of extracting periodic oscillatory features in vibration signals for detecting faults in rotating machinery. To extract the feature, we propose an approach in the short-time Fourier transform (STFT) domain where the periodic oscillatory feature manifests itself as a relatively sparse grid. To estimate the sparse grid, we formulate an optimization problem using customized binary weights in the regularizer, where the weights are formulated to promote periodicity. In order to solve the proposed optimization problem, we develop an algorithm called augmented Lagrangian majorization-minimization algorithm, which combines the split augmented Lagrangian shrinkage algorithm (SALSA) with majorization-minimization (MM), and is guaranteed to converge for both convex and non-convex formulation. As examples, the proposed approach is applied to simulated data, and used as a tool for diagnosing faults in bearings and gearboxes for real data, and compared to some state-of-the-art methods. The results show that the proposed approach can effectively detect and extract the periodical oscillatory features.
Transfer-matrix approach for finite-difference time-domain simulation of periodic structures.
Deinega, Alexei; Belousov, Sergei; Valuev, Ilya
2013-11-01
Optical properties of periodic structures can be calculated using the transfer-matrix approach, which establishes a relation between amplitudes of the wave incident on a structure with transmitted or reflected waves. The transfer matrix can be used to obtain transmittance and reflectance spectra of finite periodic structures as well as eigenmodes of infinite structures. Traditionally, calculation of the transfer matrix is performed in the frequency domain and involves linear algebra. In this work, we present a technique for calculation of the transfer matrix using the finite-difference time-domain (FDTD) method and show the way of its implementation in FDTD code. To illustrate the performance of our technique we calculate the transmittance spectra for opal photonic crystal slabs consisting of multiple layers of spherical scatterers. Our technique can be used for photonic band structure calculations. It can also be combined with existing FDTD methods for the analysis of periodic structures at an oblique incidence, as well as for modeling point sources in a periodic environment.
Directory of Open Access Journals (Sweden)
Kuang-Jung Chen
2007-01-01
Full Text Available In this study, geomagnetic data of the Lunping observatory from 1993 to 2000 are utilized for computing the amplitude variation of short-period geomagnetic total intensity data, using the complex demodulation method (CD method. In order to compare these time changes with seismicity, earthquakes that occurred within 150 km of Lunping, with magnitude ML greater than 3.0, are located. The total sum of those earthquakes, summed month by month, is correlated with the modulus. After removing seasonal effect, our results show that the modulus of periods 24, 12, and 8 hr reveals a notable change that seems to be related to the total sum of events within the whole study period. One possible precursor is found 6 months prior to the 1999 high seismicity. The modulus for the periods 24, 12, and 8 hr increased gradually from the beginning of 1999 to August 1999. After earthquake occurrence the modulus decreased again to a normal level. We propose that this notable increase might be related to a preparation process for this strong earthquake.
Duan, Gaopeng; Xiao, Feng; Wang, Long
2017-01-23
This paper focuses on the average consensus of double-integrator networked systems based on the asynchronous periodic edge-event triggered control. The asynchronous property lies in the edge event-detecting procedure. For different edges, their event detections are performed at different times and the corresponding events occur independently of each other. When an event is activated, the two adjacent agents connected by the corresponding link sample their relative state information and update their controllers. The application of incidence matrix facilitates the transformation of control objects from the agent-based to the edge-based. Practically, due to the constraints of network bandwidth and communication distance, agents usually cannot receive the instantaneous information of some others, which has an impact on the system performance. Hence, it is necessary to investigate the presence of communication time delays. For double-integrator multiagent systems with and without communication time delays, the average state consensus can be asynchronously achieved by designing appropriate parameters under the proposed event-detecting rules. The presented results specify the relationship among the maximum allowable time delays, interaction topologies, and event-detecting periods. Furthermore, the proposed protocols have the advantages of reduced communication costs and controller-updating costs. Simulation examples are given to illustrate the proposed theoretical results.
Bergeot, Nicolas; Chevalier, Jean-Marie; Bruyninx, Carine
2015-04-01
Several agencies are routinely monitoring the vertical Total Electron Content (vTEC) using GNSS data. Derived maps are available with different latencies, area extents, and grid/time resolutions. However, no high-resolution maps are publically available over Europe in near real-time. In this frame, the Royal Observatory of Belgium (ROB) developed the ROB-IONO software which takes advantage of the dense EUREF Permanent GNSS Network (EPN) to monitor the ionosphere. The main ROB products consist of ionospheric vTEC maps over Europe and their variability estimated in near real-time every 15 min on 0.5° x 0.5° grids using GPS observations. The maps are available online with a latency of ~3 min in the IONEX format at ftp://gnss.oma.be and as interactive web pages at www.gnss.be. During normal ionospheric activity, the ROB-TEC maps show a good agreement with widely used post-processed global products from IGS, CODE and ESA, with mean differences of 1.3 ± 0.9, 0.6 ± 0.7 and 0.4 ± 1.6 TECu respectively for the period 2012 to mid-2013. For a disturbed period, such as the 2003 Halloween ionospheric storm, the mean differences with IGS, CODE and ESA maps are respectively 0.9 ± 2.2, 0.1 ± 2.0 and 0.6 ± 6.8 TECu, with maximum differences (>38 TECu) occurring during the major phase of the storm. These differences are due to the lower resolution of global products in time and space compared to the ROB-TEC maps. A description of two recent events, on March 17, 2013 and February 27, 2014 highlights the capability of the method adopted to detect in near real-time abnormal ionospheric behaviour over Europe. The potential of the variability maps as an indicator of rapid ionospheric variations during the 15 min of observations is also highlighted. More than 30 ionospheric events associated with Space weather were detected during the period 2012-2014. The ionospheric perturbations are associated with Coronal Mass Ejections (CMEs, ~70% of the time), active geomagnetic conditions
Kakmeni, F M Moukam; Bowong, S; Senthikumar, D V; Kurths, J
2010-12-01
This paper studies time-delay synchronization of a periodically modulated Duffing Van der Pol (DVP) oscillator subjected to uncertainties with emphasis on complete synchronization. A robust adaptive response system is designed to synchronize with the uncertain drive periodically modulated DVP oscillator. Adaptation laws on the upper bounds of uncertainties are proposed to guarantee the boundedness of both the synchronization error and the estimated feedback coupling gains. Numerical results are presented to check the effectiveness of the proposed synchronization scheme. The results suggest that the linear and nonlinear terms in the feedback coupling play a complementary role in increasing the synchronization regime in the parameter space of the synchronization manifold. The proposed method can be successfully applied to a large variety of physical systems.
Period coded phase shifting strategy for real-time 3-D structured light illumination.
Wang, Yongchang; Liu, Kai; Hao, Qi; Lau, Daniel L; Hassebrook, Laurence G
2011-11-01
Phase shifting structured light illumination for range sensing involves projecting a set of grating patterns where accuracy is determined, in part, by the number of stripes. However, high pattern frequencies introduce ambiguities during phase unwrapping. This paper proposes a process for embedding a period cue into the projected pattern set without reducing the signal-to-noise ratio. As a result, each period of the high frequency signal can be identified. The proposed method can unwrap high frequency phase and achieve high measurement precision without increasing the pattern number. Therefore, the proposed method can significantly benefit real-time applications. The method is verified by theoretical and experimental analysis using prototype system built to achieve 120 fps at 640 × 480 resolution.
Nezhel'skaya, L. A.
2016-09-01
A flow of physical events (photons, electrons, and other elementary particles) is studied. One of the mathematical models of such flows is the modulated MAP flow of events circulating under conditions of unextendable dead time period. It is assumed that the dead time period is an unknown fixed value. The problem of estimation of the dead time period from observations of arrival times of events is solved by the method of maximum likelihood.
Time-headway distribution for periodic totally asymmetric exclusion process with various updates
Hrabák, P.; Krbálek, M.
2016-03-01
The totally asymmetric exclusion process (TASEP) with periodic boundaries is considered as traffic flow model. The large-L approximation of the stationary state is used for the derivation of the time-headway distribution (an important microscopic characteristic of traffic flow) for the model with generalized update (genTASEP) in both, forward- and backward-sequential representations. The usually used updates, fully-parallel and regular forward- and backward-sequential, are analyzed as special cases of the genTASEP. It is shown that only for those cases, the time-headway distribution is determined by the flow regardless to the density. The qualitative comparison of the results with traffic data demonstrates that the genTASEP with backward order and attractive interaction evinces similar properties of time-headway distribution as the real traffic sample.
Ultrafast time dynamics studies of periodic lattices with free electron laser radiation
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Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)
2012-11-01
It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.
Leakage-Aware Reallocation for Periodic Real-Time Tasks on Multicore Processors
Huang, Hongtao; Wang, Jijie; Lei, Siyu; Wu, Guowei
2010-01-01
It is an increasingly important issue to reduce the energy consumption of computing systems. In this paper, we consider partition based energy-aware scheduling of periodic real-time tasks on multicore processors. The scheduling exploits dynamic voltage scaling (DVS) and core sleep scheduling to reduce both dynamic and leakage energy consumption. If the overhead of core state switching is non-negligible, however, the performance of this scheduling strategy in terms of energy efficiency might degrade. To achieve further energy saving, we extend the static task scheduling with run-time task reallocation. The basic idea is to aggregate idle time among cores so that as many cores as possible could be put into sleep in a way that the overall energy consumption is reduced. Simulation results show that the proposed approach results in up to 20% energy saving over traditional leakage-aware DVS.
Kafka, K R P; Li, H; Yi, A; Cheng, J; Chowdhury, E A
2015-01-01
Time-resolved diffraction microscopy technique has been used to observe the formation of laser-induced periodic surface structures (LIPSS) from the interaction of a single femtosecond laser pulse (pump) with a nano-scale groove mechanically formed on a single-crystal Cu substrate. The interaction dynamics (0-1200 ps) was captured by diffracting a time-delayed, frequency-doubled pulse from nascent LIPSS formation induced by the pump with an infinity-conjugate microscopy setup. The LIPSS ripples are observed to form sequentially outward from the groove edge, with the first one forming after 50 ps. A 1-D analytical model of electron heating and surface plasmon polariton (SPP) excitation induced by the interaction of incoming laser pulse with the groove edge qualitatively explains the time-evloution of LIPSS formation.
Dynamical systems analysis of fluid transport in time-periodic vortex ring flows
Shariff, Karim; Leonard, Anthony; Ferziger, Joel H.
2006-04-01
It is known that the stable and unstable manifolds of dynamical systems theory provide a powerful tool for understanding Lagrangian aspects of time-periodic flows. In this work we consider two time-periodic vortex ring flows. The first is a vortex ring with an elliptical core. The manifolds provide information about entrainment and detrainment of irrotational fluid into and out of the volume transported with the ring. The likeness of the manifolds with features observed in flow visualization experiments of turbulent vortex rings suggests that a similar process might be at play. However, what precise modes of unsteadiness are responsible for stirring in a turbulent vortex ring is left as an open question. The second situation is that of two leapfrogging rings. The unstable manifold shows striking agreement with even the fine features of smoke visualization photographs, suggesting that fluid elements in the vicinity of the manifold are drawn out along it and begin to reveal its structure. We suggest that interpretations of these photographs that argue for complex vorticity dynamics ought to be reconsidered. Recently, theoretical and computational tools have been developed to locate structures analogous to stable and unstable manifolds in aperiodic, or finite-time systems. The usefulness of these analogs is demonstrated, using vortex ring flows as an example, in the paper by Shadden, Dabiri, and Marsden [Phys. Fluids 18, 047105 (2006)].
Mass flow-rate control through time periodic electro-osmotic flows in circular microchannels
Chakraborty, Suman; Ray, Subhashis
2008-08-01
The present study is directed towards devising a scientific strategy for obtaining controlled time-periodic mass flow-rate characteristics through the employment of pulsating electric fields in circular microchannels by exploiting certain intrinsic characteristics of periodic electro-osmosis phenomenon. Within the assumption of thin electrical double layers, the governing equations for potential distribution and fluid flow are derived, corresponding to a steady base state and a time-varying perturbed state, by assuming periodic forms of the imposed electrical fields and the resultant velocity fields. For sinusoidal pulsations of the electric field superimposed over its mean, a signature map depicting the amplitudes of the mass flow rate and the electrical field as well as their phase differences is obtained from the theoretical analysis as a function of a nondimensional frequency parameter for different ratios of the characteristic electric double layer thickness relative to the microchannel radius. Distinctive characteristics in the signature profiles are obtained for lower and higher frequencies, primarily attributed to the finite time scale for momentum propagation away from the walls. The signature characteristics, obtained from the solution of the prescribed sinusoidal electric field, are subsequently used to solve the "inverse" problem, where the mass flow rate is prescribed in the form of sinusoidal pulsations and the desired electric fields that would produce the required mass flow-rate variations are obtained. The analysis is subsequently extended for controlled triangular and trapezoidal pulsations in the mass flow rate and the required electric fields are successfully obtained. It is observed that the higher the double layer thickness is in comparison to the channel radius, the more prominent is the deviation of the shape of the required electric field pulsation from the desired transience in the mass flow-rate characteristics. Possible extensions of the
Directory of Open Access Journals (Sweden)
Xiaofeng Gu
2013-09-01
Full Text Available The developmental transition from a vegetative to a reproductive phase (i.e., flowering is timed by the seasonal cue day length or photoperiod in many plant species. Through the photoperiod pathway, inductive day lengths trigger the production of a systemic flowering signal, florigen, to provoke the floral transition. FLOWERING LOCUS T (FT, widely conserved in angiosperms, is a major component of the mobile florigen. In the long-day plant Arabidopsis, FT expression is rhythmically activated by the output of the photoperiod pathway CONSTANS (CO, specifically at the end of long days. How FT expression is modulated at an adequate level in response to the long-day cue to set a proper flowering time remains unknown. Here, we report a periodic histone deacetylation mechanism for the photoperiodic modulation of FT expression. We have identified a plant-unique core structural component of an Arabidopsis histone deacetylase (HDAC complex. In long days, this component accumulates at dusk, and is recruited by a MADS-domain transcription factor to the FT locus specifically at the end of the day, leading to periodic histone deacetylation of FT chromatin at dusk. Furthermore, we found that at the end of long days CO activity not only activates FT expression but also enables HDAC-activity recruitment to FT chromatin to dampen the level of FT expression, and so prevent precocious flowering in response to the inductive long-day cue. These results collectively reveal a periodic histone deacetylation mechanism for the day-length control of flowering time in higher plants.
Gu, Xiaofeng; Wang, Yizhong; He, Yuehui
2013-09-01
The developmental transition from a vegetative to a reproductive phase (i.e., flowering) is timed by the seasonal cue day length or photoperiod in many plant species. Through the photoperiod pathway, inductive day lengths trigger the production of a systemic flowering signal, florigen, to provoke the floral transition. FLOWERING LOCUS T (FT), widely conserved in angiosperms, is a major component of the mobile florigen. In the long-day plant Arabidopsis, FT expression is rhythmically activated by the output of the photoperiod pathway CONSTANS (CO), specifically at the end of long days. How FT expression is modulated at an adequate level in response to the long-day cue to set a proper flowering time remains unknown. Here, we report a periodic histone deacetylation mechanism for the photoperiodic modulation of FT expression. We have identified a plant-unique core structural component of an Arabidopsis histone deacetylase (HDAC) complex. In long days, this component accumulates at dusk, and is recruited by a MADS-domain transcription factor to the FT locus specifically at the end of the day, leading to periodic histone deacetylation of FT chromatin at dusk. Furthermore, we found that at the end of long days CO activity not only activates FT expression but also enables HDAC-activity recruitment to FT chromatin to dampen the level of FT expression, and so prevent precocious flowering in response to the inductive long-day cue. These results collectively reveal a periodic histone deacetylation mechanism for the day-length control of flowering time in higher plants.
Exact control of parity-time symmetry in periodically modulated nonlinear optical couplers
Yang, Baiyuan; Hu, QiangLin; Yu, XiaoGuang
2016-01-01
We propose a mechanism for realization of exact control of parity-time (PT) symmetry by using a periodically modulated nonlinear optical coupler with balanced gain and loss. It is shown that for certain appropriately chosen values of the modulation parameters, we can construct a family of exact analytical solutions for the two-mode equations describing the dynamics of such nonlinear couplers. These exact solutions give explicit examples that allow us to precisely manipulate the system from nonlinearity-induced symmetry breaking to PT symmetry, thus providing an analytical approach to the all-optical signal control in nonlinear PT-symmetric structures.
Geometric tools for solving the FDI problem for linear periodic discrete-time systems
Longhi, Sauro; Monteriù, Andrea
2013-07-01
This paper studies the problem of detecting and isolating faults in linear periodic discrete-time systems. The aim is to design an observer-based residual generator where each residual is sensitive to one fault, whilst remaining insensitive to the other faults that can affect the system. Making use of the geometric tools, and in particular of the outer observable subspace notion, the Fault Detection and Isolation (FDI) problem is formulated and necessary and solvability conditions are given. An algorithmic procedure is described to determine the solution of the FDI problem.
The diffusive logistic model with a free boundary in a heterogeneous time-periodic environment
Ding, Weiwei; Peng, Rui; Wei, Lei
2017-09-01
This paper is concerned with a diffusive logistic model with advection and a free boundary in a spatially heterogeneous and time periodic environment. Such a model may be used to describe the spreading of a new or invasive species with the free boundary representing the expanding front. Under more general assumptions on the initial data and the function standing for the intrinsic growth rate of the species, sharp criteria for spreading and vanishing are established, and estimates for spreading speed when spreading occurs are also derived. The obtained results considerably improve and complement the existing ones, especially those of [11,25].
Directory of Open Access Journals (Sweden)
Mia Olsson
2011-03-01
Full Text Available Hereditary periodic fever syndromes are characterized by recurrent episodes of fever and inflammation with no known pathogenic or autoimmune cause. In humans, several genes have been implicated in this group of diseases, but the majority of cases remain unexplained. A similar periodic fever syndrome is relatively frequent in the Chinese Shar-Pei breed of dogs. In the western world, Shar-Pei have been strongly selected for a distinctive thick and heavily folded skin. In this study, a mutation affecting both these traits was identified. Using genome-wide SNP analysis of Shar-Pei and other breeds, the strongest signal of a breed-specific selective sweep was located on chromosome 13. The same region also harbored the strongest genome-wide association (GWA signal for susceptibility to the periodic fever syndrome (p(raw = 2.3 × 10⁻⁶, p(genome = 0.01. Dense targeted resequencing revealed two partially overlapping duplications, 14.3 Kb and 16.1 Kb in size, unique to Shar-Pei and upstream of the Hyaluronic Acid Synthase 2 (HAS2 gene. HAS2 encodes the rate-limiting enzyme synthesizing hyaluronan (HA, a major component of the skin. HA is up-regulated and accumulates in the thickened skin of Shar-Pei. A high copy number of the 16.1 Kb duplication was associated with an increased expression of HAS2 as well as the periodic fever syndrome (p < 0.0001. When fragmented, HA can act as a trigger of the innate immune system and stimulate sterile fever and inflammation. The strong selection for the skin phenotype therefore appears to enrich for a pleiotropic mutation predisposing these dogs to a periodic fever syndrome. The identification of HA as a major risk factor for this canine disease raises the potential of this glycosaminoglycan as a risk factor for human periodic fevers and as an important driver of chronic inflammation.
The Varying Light Curve and Timings of the Ultra-short Period Contact Binary KIC 9532219
Lee, Jae Woo; Koo, Jae-Rim; Park, Jang-Ho
2016-01-01
KIC 9532219 is a W UMa-type eclipsing binary with an orbital period of 0.1981549 d that is below the short-period limit ($\\sim$0.22 d) of the period distribution for contact binaries. The {\\it Kepler} light curve of the system exhibits striking light changes in both eclipse depths and light maxima. Applying third-body and spot effects, the light-curve synthesis indicates that the eclipsing pair is currently in a marginal contact stage with a mass ratio of $q$=1.20, an orbital inclination of $i$=66.0 deg, a temperature difference of $\\Delta$ ($T_{1}$--$T_{2}$)=172 K, and a third light of $l_3$=75.9 \\%. To understand the light variations with time, we divided up the light curve into 312 segments and separately analyzed them. The results reveal that variation of eclipse depth is primarily caused by changing amounts of contamination due to the nearby star KIC9532228 between the {\\it Kepler} Quarters and that the variable O'Connell effect originates from the starspot activity on the less massive primary component....
Time-dependent Mott transition in the periodic Anderson model with nonlocal hybridization
Hofmann, Felix; Potthoff, Michael
2016-08-01
The time-dependent Mott transition in a periodic Anderson model with off-site, nearest-neighbor hybridization is studied within the framework of nonequilibrium self-energy functional theory. Using the two-site dynamical-impurity approximation, we compute the real-time dynamics of the optimal variational parameter and of different observables initiated by sudden quenches of the Hubbard-U and identify the critical interaction. The time-dependent transition is orbital selective, i.e., in the final state, reached in the long-time limit after the quench to the critical interaction, the Mott gap opens in the spectral function of the localized orbitals only. We discuss the dependence of the critical interaction and of the final-state effective temperature on the hybridization strength and point out the various similarities between the nonequilibrium and the equilibrium Mott transition. It is shown that these can also be smoothly connected to each other by increasing the duration of a U-ramp from a sudden quench to a quasi-static process. The physics found for the model with off-site hybridization is compared with the dynamical Mott transition in the single-orbital Hubbard model and with the dynamical crossover found for the real-time dynamics of the conventional Anderson lattice with on-site hybridization.
The time derivative of the kilohertz quasi-periodic oscillations in 4U 1636-53
Sanna, Andrea; Belloni, Tomaso; Altamirano, Diego
2012-01-01
We analysed all archival RXTE observations of the neutron-star low-mass X-ray binary 4U 1636-53 up to May 2010. In 528 out of 1280 observations we detected kilohertz quasi-periodic oscillations (kHz QPOs), with ~ 65% of these detections corresponding to the so-called lower kHz QPO. Using this QPO we measured, for the first time, the rate at which the QPO frequency changes as a function of QPO frequency. For this we used the spread of the QPO frequency over groups of 10 consecutive measurements, sampling timescales between 320 and 1600 s, and the time derivative of the QPO frequency over timescales of 32 to 160 s. We found that: (i) Both the QPO-frequency spread and the QPO time derivative decrease by a factor ~ 3 as the QPO frequency increases. (ii) The average value of the QPO time derivative decreases by a factor of ~ 2 as the timescale over which the derivative is measured increases from less than 64 s to 160 s. (iii) The relation between the absolute value of the QPO time derivative and the QPO frequency ...
On Bifurcating Time-Periodic Flow of a Navier-Stokes Liquid Past a Cylinder
Galdi, Giovanni P.
2016-10-01
We provide general sufficient conditions for the existence and uniqueness of branching out of a time-periodic family of solutions from steady-state solutions to the two-dimensional Navier-Stokes equations in the exterior of a cylinder. By separating the time-independent averaged component of the velocity field from its oscillatory one, we show that the problem can be formulated as a coupled elliptic-parabolic nonlinear system in appropriate and distinct function spaces, with the property that the relevant linearized operators become Fredholm of index 0. In this functional setting, the notorious difficulty of 0 being in the essential spectrum entirely disappears and, in fact, it is even meaningless. Our approach is different and, we believe, more natural and simpler than those proposed by previous authors discussing similar questions. Moreover, the latter all fail, when applied to the problem studied here.
Estimating inter-event time distributions from finite observation periods in communication networks
Kivelä, Mikko
2014-01-01
A diverse variety of processes --- including recurrent disease episodes, neuron firing, and communication patterns among humans --- can be described using inter-event 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. 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 v...
Mixer-Duplexer-Antenna Leaky-Wave System Based on Periodic Space-Time Modulation
Taravati, Sajjad
2016-01-01
We present a mixer-duplexer-antenna leaky-wave system based on periodic space-time modulation. This system operates as a full transceiver, where the upconversion and downconversion mixing operations are accomplished via space-time transitions, the duplexing operation is induced by the nonreciprocal nature of the structure, and the radiation operation is provided by the leaky-wave nature of the wave. A rigorous electromagnetic solution is derived for the dispersion relation and field distributions. The system is implemented in the form of a spatio-temporally modulated microstrip leaky-wave structure incorporating an array of sub-wavelengthly spaced varactors modulated by a harmonic wave. In addition to the overall mixer-duplexer-antenna operation, frequency beam scanning at fixed input frequency is demonstrated as one of the interesting features of the system. A prototype is realized and demonstrated by full-wave and experimental results.
Directory of Open Access Journals (Sweden)
Matheus Melo Pithon
2010-06-01
Full Text Available As new orthodontic resin adhesives continue to be marketed, rapid and sensitive tests for examining their toxic effects at the ' cell and tissue level ' are needed because patient safety has been identifi ed as a legal concept. The objective of the present study was to evaluate the cytotoxicity and degree of monomer conversion of orthodontic adhesives over different time periods. Seven adhesives: Transbond® XT, Transbond® Color Change, Quick Cure, EagleBond, Orthobond®, Fill Mágic® and Biofix® were evaluated for their cytotoxicity in L929 fibroblastic cells and for their degree of monomer conversion over different time periods. Three control groups were also analysed: Positive control (C+, consisting of Tween 80 cell detergent; Negative control (C-, consisting of PBS; and cell control (CC, consisting of cells exposed to any material. The dye-uptake technique that involves the absorption of a neutral red dye in viable cells was used for the cytotoxicity evaluation and the degree of conversion was evaluated using spectroscopy with infrared. The results showed the cytotoxicity of the adhesives at 24, 48, 72 and 168 hours. At these times, the viability values presented for these materials were statistically different from the groups CC and C- (p 0.05. In the monomer conversions there was a percentage increase of monomer conversion from 24 to 72 hours. A direct correlation could be observed between cytotoxicity and monomer conversions. From this work it can be concluded that all adhesives evaluated are cytotoxic at the times of 24, 48 and 72 hours. Monomers continued conversion even after photopolymerization had stopped.
时间序列周期模式挖掘的周期检测方法%Periodicity Detection Method of Periodic Pattern Mining in Time Series
Institute of Scientific and Technical Information of China (English)
王阅; 高学东; 武森; 陈敏
2009-01-01
周期是时间序列的重要特征之一,用于精确描述时间序列并预测其发展趋势.在现有周期模式挖掘算法中,周期长度由用户事先定义,忽略了噪声的存在.在ERP度量和时间弯曲算法的基础上,提出一种新的周期长度检测方法.该方法可以在时间轴上实现弯曲,包括延伸和平移.它受噪声干扰的影响较小,实验结果表明其性能优于原有周期检测算法.%Periodicity is an important feature for time series that can be used for describing time series exactly and predicting its development trends. In existing mining algorithms for periodic patterns, the periodicity length is user-specified in andvanc, and the presence of noise is not taken into account. Based on ERP(Edit distance with Real Penalty) measurement and time warping algorithm, this paper proposes a novel algorithm for periodicity length detection, which can realize warp on the time axis including extending and translation. It is less affected by noise interference. Experimental results show that the performance of this algorithm is better than existing periodicity detection algorithms.
Mehl, B
1993-05-01
Excellence in the pharmacy profession, particularly pharmacy management, is defined. Several factors have a significant effect on the ability to reach a given level of excellence. The first is the economic and political climate in which pharmacists practice. Stricter controls, reduced resources, and the velocity of change all necessitate nurturing of values and a work ethic to maintain excellence. Excellence must be measured by the services provided with regard to the resources available; thus, the ability to achieve excellence is a true test of leadership and innovation. Excellence is also time dependent, and today's innovation becomes tomorrow's standard. Programs that raise the level of patient care, not those that aggrandize the profession, are the most important. In addition, basic services must be practiced at a level of excellence. Quality assessment is a way to improve care and bring medical treatment to a higher plane of excellence. For such assessment to be effective and not punitive, the philosophy of the program must be known, and the goal must be clear. Excellence in practice is dependent on factors such as political and social norms, standards of practice, available resources; perceptions, time, the motivation to progress to a higher level, and the continuous innovation required to reshape the profession to meet the needs of society.
Non-AIDS defining cancers in the D:A:D Study--time trends and predictors of survival
DEFF Research Database (Denmark)
Worm, Signe W; Bower, Mark; Reiss, Peter;
2013-01-01
Non-AIDS defining cancers (NADC) are an important cause of morbidity and mortality in HIV-positive individuals. Using data from a large international cohort of HIV-positive individuals, we described the incidence of NADC from 2004-2010, and described subsequent mortality and predictors of these....
Enhanced Transport of Passive Tracers In A Time Periodic Two-dimensional Flow
Boffetta, G.; Cencini, M.; Espa, S.; Musacchio, S.
, investigating systems in which the second condition is violated is much more inter- esting. With this purpose, some experiments have shown how superdiffusion arises in a two-dimensional quasi-geostrophic (planetary-type) flow, where particles can jump for very long time in the same direction performing a Levy flight (Castiglione et al., 2001 ). Moreover, two recent papers (Vulpiani, 1998; Solomon, 2001) show how, also in very simple two-dimensional, time and space periodic cellular flows,anomalous diffusive behaviours can appear. In this paper we present an experimental study of transport in an electromagnetically forced time periodic two-dimensional flow. The flow is generated by applying an electromagnetic forcing on a thin layer of an elec- trolyte solution and reveals in a square grid of alternating vortices. Time dependence can be easily obtained by changing the time dependence of the electric fields. In par- ticular, considering certain values of the imposed oscillation frequencies, particles can display very long jump. Particle Tracking Velocimetry (PTV) is used to measure the flow field. This technique is the most suitable for studying dispersion phenomena in a Lagrangian framework allowing the direct evaluation of particle displacements and related quantities (Cenedese, Querzoli; 2000). Moreover, due to the characteristics of the analyzed flow and to the improvement of the tracking procedure, we have been able to track a great number of particles for time intervals greater than the charac- teristic time-scales of the flow. In order to characterize the time correlations we will evaluate the so-called jumps probabilities with memory which represent the probabil- ities to jump in a given direction conditioned to having experienced jumps in the same direction at previous times. Such statistics will revealed very useful and suitable for detecting the onset of the aforementioned correlations. 2
Length of Growing Period over Africa: Variability and Trends from 30 Years of NDVI Time Series
Directory of Open Access Journals (Sweden)
Mohammed Y. Said
2013-02-01
Full Text Available The spatial distribution of crops and farming systems in Africa is determined by the duration of the period during which crop and livestock water requirements are met. The length of growing period (LGP is normally assessed from weather station data—scarce in large parts of Africa—or coarse-resolution rainfall estimates derived from weather satellites. In this study, we analyzed LGP and its variability based on the 1981–2011 GIMMS NDVI3g dataset. We applied a variable threshold method in combination with a searching algorithm to determine start- and end-of-season. We obtained reliable LGP estimates for arid, semi-arid and sub-humid climates that are consistent in space and time. This approach effectively mapped bimodality for clearly separated wet seasons in the Horn of Africa. Due to cloud contamination, the identified bimodality along the Guinea coast was judged to be less certain. High LGP variability is dominant in arid and semi-arid areas, and is indicative of crop failure risk. Significant negative trends in LGP were found for the northern part of the Sahel, for parts of Tanzania and northern Mozambique, and for the short rains of eastern Kenya. Positive trends occurred across western Africa, in southern Africa, and in eastern Kenya for the long rains. Our LGP analysis provides useful information for the mapping of farming systems, and to study the effects of climate variability and other drivers of change on vegetation and crop suitability.
Dynamical generalized Hurst exponent as a tool to monitor unstable periods in financial time series
Morales, Raffaello; Di Matteo, T.; Gramatica, Ruggero; Aste, Tomaso
2012-06-01
We investigate the use of the Hurst exponent, dynamically computed over a weighted moving time-window, to evaluate the level of stability/instability of financial firms. Financial firms bailed-out as a consequence of the 2007-2008 credit crisis show a neat increase with time of the generalized Hurst exponent in the period preceding the unfolding of the crisis. Conversely, firms belonging to other market sectors, which suffered the least throughout the crisis, show opposite behaviors. We find that the multifractality of the bailed-out firms increase at the crisis suggesting that the multi fractal properties of the time series are changing. These findings suggest the possibility of using the scaling behavior as a tool to track the level of stability of a firm. In this paper, we introduce a method to compute the generalized Hurst exponent which assigns larger weights to more recent events with respect to older ones. In this way large fluctuations in the remote past are less likely to influence the recent past. We also investigate the scaling associated with the tails of the log-returns distributions and compare this scaling with the scaling associated with the Hurst exponent, observing that the processes underlying the price dynamics of these firms are truly multi-scaling.
Longhi, S
2012-01-01
Recent works [Y.D. Chong {\\it et al.}, Phys. Rev. Lett. {\\bf 105}, 053901 (2010); W. Wan {\\it et al.}, Science {\\bf 331}, 889 (2011)] have shown that the time-reversed process of lasing at threshold realizes a coherent perfect absorber (CPA). In a CPA, a lossy medium in an optical cavity with a specific degree of dissipation, equal in modulus to the gain of the lasing medium, can perfectly absorb coherent optical waves at discrete frequencies that are the time-reversed counterpart of the lasing modes. Here the concepts of time-reversal of lasing and CPA are extended for optical radiation emitted by a laser operated in an arbitrary (and generally highly-nonlinear) regime, i.e. for transient, chaotic or periodic coherent optical fields. We prove that any electromagnetic signal $E(t)$ generated by a laser system \\textbf{S} operated in an arbitrary regime can be perfectly absorbed by a CPA device $\\bf{S'}$ which is simply realized by placing inside \\textbf{S} a broadband linear absorber (attenuator) of appropriat...
A first principles TDDFT framework for spin and time-resolved ARPES in periodic systems
De Giovannini, Umberto; Rubio, Angel
2016-01-01
We present a novel theoretical approach to simulate spin, time and angular-resolved photoelectron spectroscopy (ARPES) from first principles that is applicable to surfaces, thin films, few layer systems, and low-dimensional nanostructures. The method is based on a general formulation in the framework of time-dependent density functional theory (TDDFT) to describe the real time-evolution of electrons escaping from a surface under the effect of any external (arbitrary) laser field. By extending the so called t-SURFF method to periodic systems one can calculate the final photoelectron spectrum by collecting the flux of the ionization current trough an analysing surface. The resulting approach, that we named t-SURFFP, allows to describe a wide range of irradiation conditions without any assumption on the dynamics of the ionization process allowing for pump-probe simulations on an equal footing. To illustrate the wide scope of applicability of the method we present applications to graphene, mono- and bi-layer WSe$...
Reference value of long-time exercise test in the diagnosis of primary periodic paralysis
Institute of Scientific and Technical Information of China (English)
Ding Zeyu; Liu Mingsheng; Cui Liying
2014-01-01
Background The long-time exercise test (ET) is used to diagnose the primary periodic paralyses (PPs).However the reference values of ET are many and various.This study aimed to investigate the reference value of long-time ET in the diagnosis of PPs.Methods We recruited 108 healthy subjects,68 patients with PPs,and 72 patients with other diseases for the study.The procedure of ET was made on the basis of the McManis' method.Electrical responses were recorded from right abductor digiti minimi (ADM) muscle when stimulation of the ulnar nerve at the wrist.After the compound muscle action potential (CMAP) was monitored,subjects were then asked to contract the muscle as strongly as possible for 5 minutes.CMAPs were recorded for 2 seconds immediately after cessation of exercise,then every 5 minutes for 10 minutes,and finally every 10 minutes for 50 minutes.In general,the CMAP amplitudes will fall below the pre-exercise levels in an hour.The largest decrease was calculated and used as results of ET.Results The CMAP amplitude decreases had no significant differences between groups when the healthy adults were grouped according to age,gender,height,weight and test time.Decreases in PPs patients (57.76％) were significantly more than in healthy subjects (15.21％) and other disease patients (18.10％,P ＜0.001).Receiver operating characteristic (ROC) curve analysis showed that the best threshold is 35.50％.Conclusions In the long-time exercise test,threshold of 35.50％ for the CMAP amplitude decrease was identified for abnormal.The result is not influenced by age,gender,height,weight,and test time.About 7.4％ of healthy subjects were abnormal in ET.
MULTI BAND INSAR ANALYSIS OF SUBSIDENCE DEVELOPMENT BASED ON THE LONG PERIOD TIME SERIES
Directory of Open Access Journals (Sweden)
F. C. Çomut
2015-12-01
Full Text Available The SAR Interferometry (InSAR application has shown great potential in monitoring of land terrain changes and in detection of land deformations such as subsidence. Longer time analysis can lead to understand longer trends and changes. Using different bands of SAR satellite (C- from ERS 1-2 and Envisat, L- from ALOS over the study area, we achieve knowledge of movements in long-term and evaluation of its dynamic changes within observed period of time. Results from InSAR processing fit with the position changes in vertical direction based on GPS network established over the basin as an effective geodetic network. Time series (StaMPS PS+SB of several points over Çumra County in eastern part of Konya City show a general trend of the deformation that is expected to be approximately between -13 to -17 mm/year. Northern part of Karaman is affected by faster subsidence, borders of the subsidence trough were identified from Envisat. Presenting InSAR results together with GIS information about locations and time of occurrence of sudden subsidence, urban/industrial growth in time and climate changes helps in better understanding of the situation. This way, the impact of natural and man-made changes will be shown for urban planning thanks to InSAR and GIS comparisons with hydrogeological modeling. In this study we present results of differential and multitemporal InSAR series using different bands and GIS conjunction associated with seasonal and temporal groundwater level changes in Konya Closed Basin.
Multi Band Insar Analysis of Subsidence Development Based on the Long Period Time Series
Çomut, F. C.; Ustun, A.; Lazecky, M.; Aref, M. M.
2015-12-01
The SAR Interferometry (InSAR) application has shown great potential in monitoring of land terrain changes and in detection of land deformations such as subsidence. Longer time analysis can lead to understand longer trends and changes. Using different bands of SAR satellite (C- from ERS 1-2 and Envisat, L- from ALOS) over the study area, we achieve knowledge of movements in long-term and evaluation of its dynamic changes within observed period of time. Results from InSAR processing fit with the position changes in vertical direction based on GPS network established over the basin as an effective geodetic network. Time series (StaMPS PS+SB) of several points over Çumra County in eastern part of Konya City show a general trend of the deformation that is expected to be approximately between -13 to -17 mm/year. Northern part of Karaman is affected by faster subsidence, borders of the subsidence trough were identified from Envisat. Presenting InSAR results together with GIS information about locations and time of occurrence of sudden subsidence, urban/industrial growth in time and climate changes helps in better understanding of the situation. This way, the impact of natural and man-made changes will be shown for urban planning thanks to InSAR and GIS comparisons with hydrogeological modeling. In this study we present results of differential and multitemporal InSAR series using different bands and GIS conjunction associated with seasonal and temporal groundwater level changes in Konya Closed Basin.
Zhou, Jun; Lu, Xinbiao; Qian, Huimin
2016-09-01
The paper reports interesting but unnoticed facts about irreducibility (resp., reducibility) of Flouqet factorisations and their harmonic implication in term of controllability in finite-dimensional linear continuous-time periodic (FDLCP) systems. Reducibility and irreducibility are attributed to matrix logarithm algorithms during computing Floquet factorisations in FDLCP systems, which are a pair of essential features but remain unnoticed in the Floquet theory so far. The study reveals that reducible Floquet factorisations may bring in harmonic waves variance into the Fourier analysis of FDLCP systems that in turn may alter our interpretation of controllability when the Floquet factors are used separately during controllability testing; namely, controllability interpretation discrepancy (or simply, controllability discrepancy) may occur and must be examined whenever reducible Floquet factorisations are involved. On the contrary, when irreducible Floquet factorisations are employed, controllability interpretation discrepancy can be avoided. Examples are included to illustrate such observations.
Atmospheric CO2 and climate on millennial time scales during the last glacial period.
Ahn, Jinho; Brook, Edward J
2008-10-03
Reconstructions of ancient atmospheric carbon dioxide (CO2) variations help us better understand how the global carbon cycle and climate are linked. We compared CO2 variations on millennial time scales between 20,000 and 90,000 years ago with an Antarctic temperature proxy and records of abrupt climate change in the Northern Hemisphere. CO2 concentration and Antarctic temperature were positively correlated over millennial-scale climate cycles, implying a strong connection to Southern Ocean processes. Evidence from marine sediment proxies indicates that CO2 concentration rose most rapidly when North Atlantic Deep Water shoaled and stratification in the Southern Ocean was reduced. These increases in CO2 concentration occurred during stadial (cold) periods in the Northern Hemisphere, several thousand years before abrupt warming events in Greenland.
Ordering of small particles in one-dimensional coherent structures by time-periodic flows
Pushkin, Dmitri; Shevtsova, Valentina
2011-01-01
Small particles transported by a fluid medium do not necessarily have to follow the flow. We show that for a wide class of time-periodic incompressible flows inertial particles have a tendency to spontaneously align in one-dimensional dynamic coherent structures. This effect may take place for particles so small that often they would be expected to behave as passive tracers and be used in PIV measurement technique. We link the particle tendency to form one-dimensional structures to the nonlinear phenomenon of phase locking. We propose that this general mechanism is, in particular, responsible for the enigmatic formation of the `particle accumulation structures' discovered experimentally in thermocapillary flows more than a decade ago and unexplained until now.
Multiple periodic solutions for a discrete time model of plankton allelopathy
Zhang Jianbao; Fang Hui
2006-01-01
We study a discrete time model of the growth of two species of plankton with competitive and allelopathic effects on each other N1(k+1) = N1(k)exp{r1(k)-a11(k)N1(k)-a12(k)N2(k)-b1(k)N1(k)N2(k)}, N2(k+1) = N2(k)exp{r2(k)-a21(k)N2(k)-b2(k)N1(k)N1(k)N2(k)}. A set of sufficient conditions is obtained for the existence of multiple positive periodic solutions for this model. The approach is based on Mawhin's continuation theorem of coincidence degree theory as well as some a priori estimates. Some...
Energy Technology Data Exchange (ETDEWEB)
Adesanya, S.O., E-mail: adesanyas@run.edu.ng [Department of Mathematical Sciences, College of Natural Sciences, Redeemer’s University (Nigeria); Oluwadare, E.O. [Department of Mathematical Sciences, College of Natural Sciences, Redeemer’s University (Nigeria); Falade, J.A., E-mail: faladej@run.edu.ng [Department of Physical Sciences, College of Natural Sciences, Redeemer’s University (Nigeria); Makinde, O.D., E-mail: makinded@gmail.com [Faculty of Military Science, Stellenbosch University, Private Bag X2, Saldanha 7395 (South Africa)
2015-12-15
In this paper, the free convective flow of magnetohydrodynamic fluid through a channel with time periodic boundary condition is investigated by taking the effects of Joule dissipation into consideration. Based on simplifying assumptions, the coupled governing equations are reduced to a set of nonlinear boundary valued problem. Approximate solutions are obtained by using semi-analytical Adomian decomposition method. The effect of pertinent parameters on the fluid velocity, temperature distribution, Nusselt number and skin friction are presented graphically and discussed. The result of the computation shows that an increase in the magnetic field intensity has significant influence on the fluid flow. - Highlights: • The influence of magnetic field on the free convective fluid flow is considered. • The coupled equations are solved by using Adomian decomposition method. • The Adomian series solution agreed with previously obtained result. • Magnetic field decreases the velocity maximum but enhances temperature field.
Efficiency, Power and Period of a model quantum heat engine working in a finite time
Bekele, Mulugeta; Dima, Tolasa A.; Alemye, Mekuannent; Chegeno, Warga
We take a spin-half quantum particle undergoing Carnot type cyclic process in a finite time assisted by two heat reservoirs and an external magnetic field. We find that the power of the heat engine is maximum at a particular period of the cyclic process and efficiency at the maximum power is at least half of the Carnot efficiency. We further apply the Omega-criterion for a figure of merit representing a compromise between useful power and lost power determining the corresponding efficiency for the optimization criterion to be at least three fourth of the Carnot efficiency. The authers are thankful to the International Science programme, IPS, Uppsala, Sweden for their support to our research lab.
H2 control of discrete-time periodic systems with Markovian jumps and multiplicative noise
Ma, Hongji; Jia, Yingmin
2013-10-01
This paper addresses the problem of optimal and robust H2 control for discrete-time periodic systems with Markov jump parameters and multiplicative noise. To analyse the system performance in the presence of exogenous random disturbance, an H2 norm is firstly established on the basis of Gramian matrices. Further, under the condition of exact observability, a necessary and sufficient condition is presented for the solvability of H2 optimal control problem by means of a generalised Riccati equation. When the transition probabilities of jump parameter are incompletely measurable, an H2-guaranteed cost norm is exploited and the robust H2 controller is designed through a linear matrix inequality (LMI) optimisation approach. An example of a networked control system is supplied to illustrate the proposed results.
A Partial Backlogging Inventory Model with Time-Varying Demand During Shortage Period
Directory of Open Access Journals (Sweden)
Chen Mang
2010-11-01
Full Text Available Harris’s classic square root economic order quantity (EOQ model forms the basis for many other models that relax one or more of its assumptions. A key assumption of the basic EOQ model is that stockouts are not permitted. Due to the excess demands, stock-out situations may arise occasionally. Sometimes, shortages are permitted and they are backordered and satisfied in the very next replenishment. Therefore the objective of this paper is to develop a partial backlogging inventory model, and proposes a new algorithm to minimize the total cost, at the same time also propose the prediction method and algorithm of ordering period. Finally, a practical example of the numerical analysis is given.
Observations of the April 2002 Storm Period with TIMED-TIDI
Niciejewski, R.; Killeen, T.; Wu, Q.; Skinner, W.; Solomon, S.; Ortland, D.; Kafkalidis, J.; Gell, D.; Gablehouse, D.; Johnson, R.
2002-12-01
TIDI is meeting its basic requirement, which is to measure the global wind field in the mesosphere and lower thermosphere, the core study region. Since February 2002, TIDI has been in a routine science data-taking mode. During April 2002, TIMED was positioned at a high beta angle (angle between the plane of the satellite orbit and the Earth-Sun line) resulting in a series of TIDI measurements near the dusk/dawn terminator. The field of view of TIDI allows it to obtain measurements from pole to pole, while the repetition rate of the sky-scanner allows it to obtain several scans within the auroral oval region on each orbit. This paper will discuss TIDI measurements obtained during the April 2002 storm period, including OI (5577\\x8F) intensity data and neutral wind data sets.
Judgment algorithm for periodicity of time series data based on Bayesian information criterion.
Tominaga, Daisuke; Horimoto, Katsuhisa
2008-08-01
Judgment periodicity of biological time series data is important and done widely to find the circadian expression of genes, monthly change of hormones, etc. To keep complete reproducibility of judgment is a problem because popular judgment methods such as curve fitting, Fourier analysis, etc. need judgment criteria determined by analysts considering experimental conditions and results (level, S/N, distribution, etc.) based on their experience. Judgment results are often affected by analysts' subjects. Reproducible criterion determination is therefore strongly needed. We propose introducing the information criterion to replace analysts' criteria. A judgment algorithm by combining Bayesian information criterion (BIC) and discrete Fourier transform (DFT) has been developed and has proved its ability through application to mice microarray data and finding of circadian genes. Our method, named "Piccolo", shows higher sensitivity than the simple DFT (without BIC) method with reproducibility, and can be fully automated.
Multiple periodic solutions for a discrete time model of plankton allelopathy
Zhang Jianbao; Fang Hui
2006-01-01
We study a discrete time model of the growth of two species of plankton with competitive and allelopathic effects on each other N1(k+1) = N1(k)exp{r1(k)-a11(k)N1(k)-a12(k)N2(k)-b1(k)N1(k)N2(k)}, N2(k+1) = N2(k)exp{r2(k)-a21(k)N2(k)-b2(k)N1(k)N1(k)N2(k)}. A set of sufficient conditions is obtained for the existence of multiple positive periodic solutions for this model. The approach is based on Mawhin's continuation theorem of coincidence degree theory as well as some a priori estimates. Some...
Cha, Jae H.; Abbott, A. Lynn; Szu, Harold H.; Willey, Jefferson; Landa, Joseph; Krapels, Keith A.
2014-05-01
Software-defined Cameras (SDC) based on Boltzmann's molecular thermodynamics can "see" through visually-degraded fields such as fire, fog, and dust in some situations. This capability is possible by means of unsupervised learning implemented on a neuromorphic algo-tecture. This paper describes the SDC algorithm design strategy with respect to nontrivial solutions, stability, and accuracy. An example neuromorphic learning algorithm is presented along with unsupervised learning stopping criteria.
Low-thrust roundtrip trajectories to Mars with one-synodic-period repeat time
Okutsu, Masataka; Landau, Damon F.; Rogers, Blake A.; Longuski, James M.
2015-05-01
Cycler trajectories-both ballistic and powered-are reported in the literature in which there are two-vehicle, three-vehicle, and four-vehicle cases. Such trajectories permit the installation of cycler vehicles which provide safe and comfortable living conditions for human space travel between Earth and Mars during every synodic opportunity. The question the present paper answers is a logical, obvious one: Does a single-vehicle, one-synodic-period cycler exist? The answer is yes: such a trajectory can be flown-but only with a high-power electric propulsion system. In our example, it is found that "stopover" trajectories that spend 30 days in orbit about Earth and 30 days about Mars, and return astronauts to Earth in one synodic period require a 90-t power generator with a power level of 11 MWe. Fortuitously, and in lieu of using chemical propulsion, the high power level of the electric propulsion system would also be effective in hauling the cargo payload via a spiral trajectory about the Earth. But because one synodic period is not enough for the cycler vehicle to fly both the interplanetary trajectories and the Earth-spiral trajectories, we suggest developing two nuclear power generators, which could alternate flying the interplanetary trajectories and the Earth-spiral trajectories. Once these power generators are launched and begin operating in space, the mass requirement in seven subsequent missions (over a period of 15 years beginning in 2022) would be modest at 250-300 metric tons to low-Earth orbit per mission. Thus two cargo launches of NASA's Space Launch System and one crew launch of the Falcon Heavy, for example, would be adequate to maintain support for each consecutive mission. Although we propose developing two sets of electric propulsion systems to account for the Earth-spiral phases, only one vehicle is flown on a heliocentric trajectory at any given time. Thus, our low-thrust stopover cycler with zero encounter velocities falls into a category of a
Wu, Yanan; Gong, Yubing; Xu, Bo
2013-12-01
Recently, multiple coherence resonance induced by time delay has been observed in neuronal networks with constant coupling strength. In this paper, by employing Newman-Watts Hodgkin-Huxley neuron networks with time-periodic coupling strength, we study how the temporal coherence of spiking behavior and coherence resonance by time delay change when the frequency of periodic coupling strength is varied. It is found that delay induced coherence resonance is dependent on periodic coupling strength and increases when the frequency of periodic coupling strength increases. Periodic coupling strength can also induce multiple coherence resonance, and the coherence resonance occurs when the frequency of periodic coupling strength is approximately multiple of the spiking frequency. These results show that for periodic coupling strength time delay can more frequently optimize the temporal coherence of spiking activity, and periodic coupling strength can repetitively optimize the temporal coherence of spiking activity as well. Frequency locking may be the mechanism for multiple coherence resonance induced by periodic coupling strength. These findings imply that periodic coupling strength is more efficient for enhancing the temporal coherence of spiking activity of neuronal networks, and thus it could play a more important role in improving the time precision of information processing and transmission in neural networks.
40 CFR 270.215 - How are time periods in the requirements in this subpart and my RAP computed?
2010-07-01
... requirements in this subpart and my RAP computed? 270.215 Section 270.215 Protection of Environment... HAZARDOUS WASTE PERMIT PROGRAM Remedial Action Plans (RAPs) Operating Under Your Rap § 270.215 How are time periods in the requirements in this subpart and my RAP computed? (a) Any time period scheduled to begin on...
DEFF Research Database (Denmark)
liu, weiwei; Huangfu, Hao; Xiong, Jing
2014-01-01
This study proposed a method to determine time period of thermal adaption for occupants in naturally ventilated building, and analyzed the synergistic and separate feedback effect of the physical and psychological adaption modes on the time period of thermal adaption. Using the method, the values......, under the synergistic feedback effect of the physical and psychological adaption modes. The time period of thermal adaption increased to 13 days, if only the feedback effect of the physical adaption mode was accounted for. The difference between the two values of the time period of thermal adaption...... of the time period of thermal adaption were obtained on the basis of the data from a long-term field survey conducted in two typical naturally ventilated offices located in Changsha, China. The results showed that the occupants need to take 4.25 days to fully adapt to a step-change in outdoor air temperature...
Borisov, A A; Bruevich, V V; Rozgacheva, I K; Shimanovskaya, E V
2015-01-01
We applied the method of continuous wavelet-transform to high-quality time-frequency analysis to the sets of observations of relative sunspot numbers. Wavelet analysis of these data reveals the following pattern: at the same time there are several activity cycles whose periods vary widely from the quasi biennial up to the centennial period. These relatively low-frequency periodic variations of the solar activity gradually change the values of periods of different cycles in time. This phenomenon can be observed in every cycle of activity.
Acute effect of different time periods of passive static stretching on the hamstring flexibility.
Cini, Anelize; de Vasconcelos, Gabriela Souza; Lima, Claudia Silveira
2017-01-01
Several factors are associated with the presence of chronic low back pain; one of them is the flexibility of the hamstring muscles that influences the posture of the pelvic spine. Investigate the influence of two different time periods of passive static stretching on the flexibility of the hamstring. Forty-six physiotherapy students were divided into two groups performing stretching exercises: 30 s and 60 s duration. The collections consisted of: (1) pre-test: evaluation of the flexibility of the hip and knee, using a manual goniometer by means of the following tests: Straight Leg Raise Test (SLR), Passive Hip Flexion Test (PHFT) and Modified Knee Extension Test (MKET), (2) intervention: stretching with different runtimes, (3) post-test: reappraisal of flexibility, conducted immediately after the intervention. Significant difference was observed intra groups, group that did stretching exercises lasting 30 seconds (G30) (SLR p = 0.000. PHFT p = 0.003 and MKET p = 0.000) and group that did stretching exercises lasting 60 seconds (G60) (SLR p = 0.000. PHFT p = 0.001 and MKET p = 0.002). Comparing the groups, no significant difference was found (SLR p = 0.307; PHFT p = 0.904; MKET p = 0.132). Thus it can be inferred that 30 seconds are sufficient for increased flexibility of young women. Therefore the time-treatment sessions can be optimized. Only the acute effect of stretching was observed; further investigation of the long-term effect is required.
Estimating interevent time distributions from finite observation periods in communication networks.
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.
Directory of Open Access Journals (Sweden)
Jennifer Tsui
2010-06-01
Full Text Available The retinotectal projection in Xenopus laevis has been shown to exhibit correlation-based refinement of both anatomical and functional connectivity during development. Spike timing-dependent plasticity (STDP is an appealing experimental model for correlation-based synaptic plasticity because, in contrast to plasticity induction paradigms using tetanic stimulation or sustained postsynaptic depolarization, its induction protocol more closely resembles natural physiological activity. In Xenopus tadpoles, where anatomical remodeling has been reported throughout much of the life of the animal, in vivo retinotectal STDP has only been examined under a limited set of experimental conditions. Using perforated patch recordings of retina-evoked EPSCs in tectal neurons, we confirmed that repeatedly driving a retinotectal EPSP 5-10 ms prior to inducing an action potential in the postsynaptic cell, reliably produced timing-dependent long-term potentiation (t-LTP of the retinotectal synapse in young wild type tadpoles (stages 41-44. At these stages, retinotectal timing-dependent long-term depression (t-LTD also could be induced by evoking an EPSP to arrive 5-10 ms after an action potential in the tectal cell. However, retinotectal STDP using this standard protocol was limited to a developmental sensitive period, as we were unable to induce t-LTP or t-LTD after stage 44. Surprisingly, this STDP protocol also failed to induce reliable STDP in albino tadpoles at the early ages when it was effective in wild type pigmented animals. Nonetheless, low-frequency flashes to the eye produced a robust NMDA receptor-dependent retinotectal LTD in stage 47 albino tadpoles, demonstrating that the retinotectal synapse can nonetheless be modified in these animals using different plasticity paradigms.
Carter, Patricia; Price, Larry R.; Champion, Jane Dimmitt; Nichols, Francine
2017-01-01
Psychological distress, defined as depression, anxiety, and insomnia in this study, can occur following the birth of a baby as new mothers, in addition to marked physiological changes, are faced with adapting to new roles and responsibilities. We investigated the cooccurrence of stress, depression, anxiety, and insomnia in mothers during the postpartum period; tested the feasibility of study methods and procedures for use in this population; and identified new mothers interest in using cranial electrotherapy stimulation (CES) as an intervention for reducing psychological distress. We recruited healthy, low-risk, English speaking first-time mothers, ages 18–32 years, with healthy babies (N = 33), within 12 months of an uncomplicated birth. Participants completed the PSS, HAM-D14, HAM-A17, and PSQI19. No problems were encountered with study procedures. Mothers reported a high interest (4.9) in the potential use of CES to treat or prevent the occurrence of psychological distress. All participants (N = 33) reported moderate levels of depression and anxiety, while 75.8% (n = 25) reported insomnia. PSS scores were within the norms for healthy women. Further research is recommended to investigate if our findings can be replicated or if different patterns of associations emerge. Implications for clinical practice are addressed. PMID:28191350
Directory of Open Access Journals (Sweden)
Christina Murphey
2017-01-01
Full Text Available Psychological distress, defined as depression, anxiety, and insomnia in this study, can occur following the birth of a baby as new mothers, in addition to marked physiological changes, are faced with adapting to new roles and responsibilities. We investigated the cooccurrence of stress, depression, anxiety, and insomnia in mothers during the postpartum period; tested the feasibility of study methods and procedures for use in this population; and identified new mothers interest in using cranial electrotherapy stimulation (CES as an intervention for reducing psychological distress. We recruited healthy, low-risk, English speaking first-time mothers, ages 18–32 years, with healthy babies (N=33, within 12 months of an uncomplicated birth. Participants completed the PSS, HAM-D14, HAM-A17, and PSQI19. No problems were encountered with study procedures. Mothers reported a high interest (4.9 in the potential use of CES to treat or prevent the occurrence of psychological distress. All participants (N=33 reported moderate levels of depression and anxiety, while 75.8% (n=25 reported insomnia. PSS scores were within the norms for healthy women. Further research is recommended to investigate if our findings can be replicated or if different patterns of associations emerge. Implications for clinical practice are addressed.
Time-Based Measurement of Personal Mite Allergen Bioaerosol Exposure over 24 Hour Periods.
Tovey, Euan R; Liu-Brennan, Damien; Garden, Frances L; Oliver, Brian G; Perzanowski, Matthew S; Marks, Guy B
2016-01-01
Allergic diseases such as asthma and rhinitis are common in many countries. Globally the most common allergen associated with symptoms is produced by house dust mites. Although the bed has often been cited as the main site of exposure to mite allergens, surprisingly this has not yet been directly established by measurement due to a lack of suitable methods. Here we report on the development of novel methods to determine the pattern of personal exposure to mite allergen bioaerosols over 24-hour periods and applied this in a small field study using 10 normal adults. Air was sampled using a miniature time-based air-sampler of in-house design located close to the breathing zone of the participants, co-located with a miniature time-lapse camera. Airborne particles, drawn into the sampler at 2L/min via a narrow slot, were impacted onto the peripheral surface of a disk mounted on the hour-hand of either a 12 or 24 hour clock motor. The impaction surface was either an electret cloth, or an adhesive film; both novel for these purposes. Following a review of the time-lapse images, disks were post-hoc cut into subsamples corresponding to eight predetermined categories of indoor or outdoor location, extracted and analysed for mite allergen Der p 1 by an amplified ELISA. Allergen was detected in 57.2% of the total of 353 subsamples collected during 20 days of sampling. Exposure patterns varied over time. Higher concentrations of airborne mite allergen were typically measured in samples collected from domestic locations in the day and evening. Indoor domestic Der p 1 exposures accounted for 59.5% of total exposure, whereas total in-bed-asleep exposure, which varied 80 fold between individuals, accounted overall for 9.85% of total exposure, suggesting beds are not often the main site of exposure. This study establishes the feasibility of novel methods for determining the time-geography of personal exposure to many bioaerosols and identifies new areas for future technical
Time-Based Measurement of Personal Mite Allergen Bioaerosol Exposure over 24 Hour Periods.
Directory of Open Access Journals (Sweden)
Euan R Tovey
Full Text Available Allergic diseases such as asthma and rhinitis are common in many countries. Globally the most common allergen associated with symptoms is produced by house dust mites. Although the bed has often been cited as the main site of exposure to mite allergens, surprisingly this has not yet been directly established by measurement due to a lack of suitable methods. Here we report on the development of novel methods to determine the pattern of personal exposure to mite allergen bioaerosols over 24-hour periods and applied this in a small field study using 10 normal adults. Air was sampled using a miniature time-based air-sampler of in-house design located close to the breathing zone of the participants, co-located with a miniature time-lapse camera. Airborne particles, drawn into the sampler at 2L/min via a narrow slot, were impacted onto the peripheral surface of a disk mounted on the hour-hand of either a 12 or 24 hour clock motor. The impaction surface was either an electret cloth, or an adhesive film; both novel for these purposes. Following a review of the time-lapse images, disks were post-hoc cut into subsamples corresponding to eight predetermined categories of indoor or outdoor location, extracted and analysed for mite allergen Der p 1 by an amplified ELISA. Allergen was detected in 57.2% of the total of 353 subsamples collected during 20 days of sampling. Exposure patterns varied over time. Higher concentrations of airborne mite allergen were typically measured in samples collected from domestic locations in the day and evening. Indoor domestic Der p 1 exposures accounted for 59.5% of total exposure, whereas total in-bed-asleep exposure, which varied 80 fold between individuals, accounted overall for 9.85% of total exposure, suggesting beds are not often the main site of exposure. This study establishes the feasibility of novel methods for determining the time-geography of personal exposure to many bioaerosols and identifies new areas for
Directory of Open Access Journals (Sweden)
Kitajima,Takuji
2006-06-01
Full Text Available
To evaluate recent improvements in lung cancer screening, we compared the results of recently conducted lung cancer screening with those of a previous screening. This study compared the survival of lung cancer patients detected by lung cancer screening conducted between 1976 and 1984 (early period with that conducted between 1989 and 1997 (late period. Two hundred seventy-six patients with lung cancer were detected in the early period and 541 patients with lung cancer were detected in the late period. The median survival time (late : 49.8 vs. early : 27.8 months and the 5-year survival rate (late : 47.8 vs. early : 34.8% of the patients with lung cancer detected in the late period were significantly better than those in the early period (p = 0.0054. Among patients undergoing resection, the proportion of pathological stage I patients in the late period was significantly higher than that in the early period (late : 60.8 vs. early : 54.9%, p = 0.005. Multivariate analysis showed that the screening time period was a significant prognostic factor (hazard ratio = 0.685, 95% confidence interval : 0.563-0.832, p = 0.0002. These results were consistent with the findings of case-control studies of lung cancer screening programs in the late period recently conducted in Japan, which also showed a greater efficacy for screening than for previous case-control studies in the early period.
Kitajima, Takuji; Nishii, Kenji; Ueoka, Hiroshi; Shibayama, Takuo; Gemba, Kenichi; Kodani, Tsuyoshi; Kiura, Katsuyuki; Tabata, Masahiro; Hotta, Katsuyuki; Tanimoto, Mitsune; Sobue, Tomotaka
2006-06-01
To evaluate recent improvements in lung cancer screening, we compared the results of recently conducted lung cancer screening with those of a previous screening. This study compared the survival of lung cancer patients detected by lung cancer screening conducted between 1976 and 1984 (early period) with that conducted between 1989 and 1997 (late period). Two hundred seventy-six patients with lung cancer were detected in the early period and 541 patients with lung cancer were detected in the late period. The median survival time (late : 49.8 vs. early : 27.8 months) and the 5-year survival rate (late : 47.8 vs. early : 34.8%) of the patients with lung cancer detected in the late period were significantly better than those in the early period (p = 0.0054). Among patients undergoing resection, the proportion of pathological stage I patients in the late period was significantly higher than that in the early period (late : 60.8 vs. early : 54.9%, p = 0.005). Multivariate analysis showed that the screening time period was a significant prognostic factor (hazard ratio = 0.685, 95% confidence interval : 0.563-0.832, p = 0.0002). These results were consistent with the findings of case-control studies of lung cancer screening programs in the late period recently conducted in Japan, which also showed a greater efficacy for screening than for previous case-control studies in the early period.
Generational and time period differences in American adolescents' religious orientation, 1966-2014.
Directory of Open Access Journals (Sweden)
Jean M Twenge
Full Text Available In four large, nationally representative surveys (N = 11.2 million, American adolescents and emerging adults in the 2010s (Millennials were significantly less religious than previous generations (Boomers, Generation X at the same age. The data are from the Monitoring the Future studies of 12th graders (1976-2013, 8th and 10th graders (1991-2013, and the American Freshman survey of entering college students (1966-2014. Although the majority of adolescents and emerging adults are still religiously involved, twice as many 12th graders and college students, and 20%-40% more 8th and 10th graders, never attend religious services. Twice as many 12th graders and entering college students in the 2010s (vs. the 1960s-70s give their religious affiliation as "none," as do 40%-50% more 8th and 10th graders. Recent birth cohorts report less approval of religious organizations, are less likely to say that religion is important in their lives, report being less spiritual, and spend less time praying or meditating. Thus, declines in religious orientation reach beyond affiliation to religious participation and religiosity, suggesting a movement toward secularism among a growing minority. The declines are larger among girls, Whites, lower-SES individuals, and in the Northeastern U.S., very small among Blacks, and non-existent among political conservatives. Religious affiliation is lower in years with more income inequality, higher median family income, higher materialism, more positive self-views, and lower social support. Overall, these results suggest that the lower religious orientation of Millennials is due to time period or generation, and not to age.
Generational and time period differences in American adolescents' religious orientation, 1966-2014.
Twenge, Jean M; Exline, Julie J; Grubbs, Joshua B; Sastry, Ramya; Campbell, W Keith
2015-01-01
In four large, nationally representative surveys (N = 11.2 million), American adolescents and emerging adults in the 2010s (Millennials) were significantly less religious than previous generations (Boomers, Generation X) at the same age. The data are from the Monitoring the Future studies of 12th graders (1976-2013), 8th and 10th graders (1991-2013), and the American Freshman survey of entering college students (1966-2014). Although the majority of adolescents and emerging adults are still religiously involved, twice as many 12th graders and college students, and 20%-40% more 8th and 10th graders, never attend religious services. Twice as many 12th graders and entering college students in the 2010s (vs. the 1960s-70s) give their religious affiliation as "none," as do 40%-50% more 8th and 10th graders. Recent birth cohorts report less approval of religious organizations, are less likely to say that religion is important in their lives, report being less spiritual, and spend less time praying or meditating. Thus, declines in religious orientation reach beyond affiliation to religious participation and religiosity, suggesting a movement toward secularism among a growing minority. The declines are larger among girls, Whites, lower-SES individuals, and in the Northeastern U.S., very small among Blacks, and non-existent among political conservatives. Religious affiliation is lower in years with more income inequality, higher median family income, higher materialism, more positive self-views, and lower social support. Overall, these results suggest that the lower religious orientation of Millennials is due to time period or generation, and not to age.
Generational and Time Period Differences in American Adolescents’ Religious Orientation, 1966–2014
Twenge, Jean M.; Exline, Julie J.; Grubbs, Joshua B.; Sastry, Ramya; Campbell, W. Keith
2015-01-01
In four large, nationally representative surveys (N = 11.2 million), American adolescents and emerging adults in the 2010s (Millennials) were significantly less religious than previous generations (Boomers, Generation X) at the same age. The data are from the Monitoring the Future studies of 12th graders (1976–2013), 8th and 10th graders (1991–2013), and the American Freshman survey of entering college students (1966–2014). Although the majority of adolescents and emerging adults are still religiously involved, twice as many 12th graders and college students, and 20%–40% more 8th and 10th graders, never attend religious services. Twice as many 12th graders and entering college students in the 2010s (vs. the 1960s–70s) give their religious affiliation as “none,” as do 40%–50% more 8th and 10th graders. Recent birth cohorts report less approval of religious organizations, are less likely to say that religion is important in their lives, report being less spiritual, and spend less time praying or meditating. Thus, declines in religious orientation reach beyond affiliation to religious participation and religiosity, suggesting a movement toward secularism among a growing minority. The declines are larger among girls, Whites, lower-SES individuals, and in the Northeastern U.S., very small among Blacks, and non-existent among political conservatives. Religious affiliation is lower in years with more income inequality, higher median family income, higher materialism, more positive self-views, and lower social support. Overall, these results suggest that the lower religious orientation of Millennials is due to time period or generation, and not to age. PMID:25962174
Krishnan, Anath Rau; Hamzah, Ahmad Aizuddin
2017-08-01
It is crucial for a zakat institution to evaluate and understand how efficiently they have operated in the past, thus ideal strategies could be developed for future improvement. However, evaluating the efficiency of a zakat institution is actually a challenging process as it involves the presence of multiple inputs or/and outputs. This paper proposes a step-by-step procedure comprising two data envelopment analysis models, namely dual Charnes-Cooper-Rhodes and slack-based model to quantitatively measure the overall efficiency of a zakat institution over a period of time. The applicability of the proposed procedure was demonstrated by evaluating the efficiency of Pusat Zakat Sabah, Malaysia from the year of 2007 up to 2015 by treating each year as a decision making unit. Two inputs (i.e. number of staff and number of branches) and two outputs (i.e. total collection and total distribution) were used to measure the overall efficiency achieved each year. The causes of inefficiency and strategy for future improvement were discussed based on the results.
Resonant cyclotron acceleration of particles by a time periodic singular flux tube
Asch, Joachim; Stovicek, Pavel
2010-01-01
We study the dynamics of a classical nonrelativistic charged particle moving on a punctured plane under the influence of a homogeneous magnetic field and driven by a periodically time-dependent singular flux tube through the hole. We observe an effect of resonance of the flux and cyclotron frequencies. The particle is accelerated to arbitrarily high energies even by a flux of small field strength which is not necessarily encircled by the cyclotron orbit; the cyclotron orbits blow up and the particle oscillates between the hole and infinity. We support this observation by an analytic study of an approximation for small amplitudes of the flux which is obtained with the aid of averaging methods. This way we derive asymptotic formulas that are afterwards shown to represent a good description of the accelerated motion even for fluxes which are not necessarily small. More precisely, we argue that the leading asymptotic terms may be regarded as approximate solutions of the original system in the asymptotic domain as...
Time Periodic Electroosmotic Flow of The Generalized Maxwell Fluids in a Semicircular Microchannel
Institute of Scientific and Technical Information of China (English)
BAO Li-Ping; JIAN Yong-Jun; CHANG Long; SU Jie; ZHANG Hai-Yan; LIU Quan-Sheng
2013-01-01
Analytical solutions are presented using method of separation of variables for the time periodic electroosmotic flow (EOF) of linear viscoelastic fluids in semicircular microchannel.The linear viscoelastic fluids used here are described by the general Maxwell model.The solution involves analytically solving the linearized Poisson-Boltzmann (P-B) equation,together with the Cauchy momentum equation and the general Maxwell constitutive equation.By numerical computations,the influences of electric oscillating Reynolds number Re and Deborah number De on velocity amplitude are presented.For small Re,results show that the larger velocity amplitudeis confined to the region near the charged wall when De is small.With the increase of the Deborah number De,the velocity far away the charged wall becomes larger for large Deborah number De.However,for larger Re,the oscillating characteristic of the velocity amplitude occurs and becomes significant with the increase of De,especially for larger Deborah number.
The High Time Resolution Universe Survey - IX: Polarimetry of long-period pulsars
Tiburzi, C; Bailes, M; Bates, S D; Bhat, N D R; Burgay, M; Burke-Spolaor, S; Champion, D; Coster, P; D'Amico, N; Keith, M J; Kramer, M; Levin, L; Milia, S; Ng, C; Possenti, A; Stappers, B W; Thornton, D; van Straten, W
2013-01-01
We present a polarimetric analysis of 49 long-period pulsars discovered as part of the High Time Resolution Universe (HTRU) southern survey. The sources exhibit the typical characteristics of "old" pulsars, with low fractional linear and circular polarisation and narrow, multicomponent profiles. Although the position angle swings are generally complex, for two of the analysed pulsars (J1622-3751 and J1710-2616) we obtained an indication of the geometry via the rotating vector model. We were able to determine a value of the rotation measure (RM) for 34 of the sources which, when combined with their dispersion measures (DM), yields an integrated magnetic field strength along the line of sight. With the data presented here, the total number of values of RM associated to pulsars discovered during the HTRU southern survey sums to 51. The RMs are not consistent with the hypothesis of a counter-clockwise direction of the Galactic magnetic field within an annulus included between 4 and 6 kpc from the Galactic centre....
Platelet aggregation responses vary over a period of time in healthy controls.
Refaai, Majed A; Frenkel, Eugene; Sarode, Ravi
2010-01-01
Platelet aggregation study is performed to investigate platelet function abnormality. A normal healthy control sample is usually run with the patient sample as a quality control measure. At our institution, we observed variations in platelet aggregation responses in our normal repeat controls. Therefore, we analysed aggregation parameters in these controls. Whole blood aggregation studies were performed with adenosine diphosphate (ADP), arachidonic acid (AA), collagen and ristocetin. Adenosine triphosphate (ATP) secretion was also measured simultaneously by leuciferin-leuciferase reaction. During a 5-year period, a total of 86 studies were performed on seven controls. Aggregations were within the acceptable range in 67% of the time. Collagen was the most affected agonist in our study. On five occasions, four controls had subnormal aggregations with two agonists. All abnormal responses were hypoaggregation except for two who had hyperaggregation with collagen and AA. Only one out of seven controls was always normal. In the presence of a subnormal control result, a new control was run before releasing the patient's platelet aggregation results. These findings suggest that many physiological factors, other than medications, may affect platelet function even in normal individuals. Therefore, a repeat study at a later date to demonstrate a reproducible abnormality would be prudent before labeling a patient's platelets abnormal.
Chen, J. H.; Wasserburg, G. J.; Ku, T.-L.; Edwards, R. Lawrence
1987-01-01
The development of mass spectrometric techniques for determination of Th-230 abundance has made it possible to reduce analytical errors in (U-238)-(U-234)-(Th-230) dating of corals even with very small samples. Samples of 6 x 10 to the 8th atoms of Th-230 can be measured to an accuracy of + or - 3 percent (2sigma), and 3 x 10 to the 10th atoms of Th-230 can be measured to an accuracy of + or - 0.2 percent. The time range over which useful age data on corals can be obtained now ranges from about 50 to about 500,000 years. For young corals, this approach may be preferable to C-14 dating. The precision with which the age of a coral can now be determined should make it possible to critically test the Milankovitch hypothesis concerning Pleistocene climate fluctuations. Analyses of a number of corals that grew during the last interglacial period yield ages of 122,000 to 130,000 years. The ages coincide with, or slightly post-date, the summer solar insolation high at 65 deg N latitude which occurred 128,000 years ago. This supports the idea that changes in Pleistocene climate can be the result of variations in the distribution of solar insolation caused by changes in the geometry of the earth's orbit and rotation axis.
Chen, J. H.; Wasserburg, G. J.; Ku, T.-L.; Edwards, R. Lawrence
1987-01-01
The development of mass spectrometric techniques for determination of Th-230 abundance has made it possible to reduce analytical errors in (U-238)-(U-234)-(Th-230) dating of corals even with very small samples. Samples of 6 x 10 to the 8th atoms of Th-230 can be measured to an accuracy of + or - 3 percent (2sigma), and 3 x 10 to the 10th atoms of Th-230 can be measured to an accuracy of + or - 0.2 percent. The time range over which useful age data on corals can be obtained now ranges from about 50 to about 500,000 years. For young corals, this approach may be preferable to C-14 dating. The precision with which the age of a coral can now be determined should make it possible to critically test the Milankovitch hypothesis concerning Pleistocene climate fluctuations. Analyses of a number of corals that grew during the last interglacial period yield ages of 122,000 to 130,000 years. The ages coincide with, or slightly post-date, the summer solar insolation high at 65 deg N latitude which occurred 128,000 years ago. This supports the idea that changes in Pleistocene climate can be the result of variations in the distribution of solar insolation caused by changes in the geometry of the earth's orbit and rotation axis.
Directory of Open Access Journals (Sweden)
K. Ide
2002-01-01
Full Text Available In this paper we develop analytical and numerical methods for finding special hyperbolic trajectories that govern geometry of Lagrangian structures in time-dependent vector fields. The vector fields (or velocity fields may have arbitrary time dependence and be realized only as data sets over finite time intervals, where space and time are discretized. While the notion of a hyperbolic trajectory is central to dynamical systems theory, much of the theoretical developments for Lagrangian transport proceed under the assumption that such a special hyperbolic trajectory exists. This brings in new mathematical issues that must be addressed in order for Lagrangian transport theory to be applicable in practice, i.e. how to determine whether or not such a trajectory exists and, if it does exist, how to identify it in a sequence of instantaneous velocity fields. We address these issues by developing the notion of a distinguished hyperbolic trajectory (DHT. We develop an existence criteria for certain classes of DHTs in general time-dependent velocity fields, based on the time evolution of Eulerian structures that are observed in individual instantaneous fields over the entire time interval of the data set. We demonstrate the concept of DHTs in inhomogeneous (or "forced" time-dependent linear systems and develop a theory and analytical formula for computing DHTs. Throughout this work the notion of linearization is very important. This is not surprising since hyperbolicity is a "linearized" notion. To extend the analytical formula to more general nonlinear time-dependent velocity fields, we develop a series of coordinate transforms including a type of linearization that is not typically used in dynamical systems theory. We refer to it as Eulerian linearization, which is related to the frame independence of DHTs, as opposed to the Lagrangian linearization, which is typical in dynamical systems theory, which is used in the computation of Lyapunov exponents. We
Lee, Dongwook; Kim, JongWon
2003-11-01
Streaming media applications over mobile IP networks suffer from playback disruptions resulting from handoff blackout period as well as bandwidth fluctuation. To overcome buffer shortage, pre-buffering technique can be adopted where the client stores sufficient amount of stream in advance. However, under the mobile IP handoff that may take up to several seconds, it is extremely difficult to sustain seamless playback. Inaccurate and conservative choice on the required buffering size can waste limited latency budget, resulting in quality degradation. In this paper, we are extending--from smooth handoff to fast handoff of mobile IPv6--the transient time analysis recently proposed to approximate transient time durations, STP (silent time period) and UTP (unstable time period). The approximated time periods are utilized to estimate the required buffering buffer size accurately. Network simulation result evaluted under simplified buffering strategies shows that the proposed scheme can provide appropriate guideline on the buffer parameters and thus can improve seamless streaming.
Dodd, Antony N; Dalchau, Neil; Gardner, Michael J; Baek, Seong-Jin; Webb, Alex A R
2014-01-01
A circadian rhythm matched to the phase and period of the day-night cycle has measurable benefits for land plants. We assessed the contribution of circadian period to the phasing of cellular events with the light : dark cycle. We also investigated the plasticity of circadian period within the Arabidopsis circadian oscillator. We monitored the circadian oscillator in wild-type and circadian period mutants under light : dark cycles of varying total duration. We also investigated changes in oscillator dynamics during and after the transition from light : dark cycles to free running conditions. Under light : dark cycles, dawn and dusk were anticipated differently when the circadian period was not resonant with the environmental period ('T cycle'). Entrainment to T cycles differing from the free-running period caused a short-term alteration in oscillator period. The transient plasticity of period was described by existing mathematical models of the Arabidopsis circadian network. We conclude that a circadian period resonant with the period of the environment is particularly important for anticipation of dawn and the timing of nocturnal events; and there is short-term and transient plasticity of period of the Arabidopsis circadian network.
It's T time: A study on the return period of multivariate problems
Michailidi, Eleni Maria; Balistrocchi, Matteo; Bacchi, Baldassare
2016-04-01
One of the most important tasks a hydrologist must face is the proper estimation of the 'design values' of a natural variable corresponding to a given Return Period, T, of failures of the hydraulic 'structure' to be designed or verified. Sometimes the 'structure' is simply the embankments, the failure of which corresponds to the outflows of flood runoff on the surrounding land. The widely adopted definition of T, in a problem regarding the maxima of hydrological variables, is "the average time elapsing between two successive occurrences of an event exceeding a certain magnitude of the natural variables". If T is referred to the minima, the symmetric definition pertains to the "average time between two periods during which the variable ranges below a given magnitude". Conventional (and the only accepted) approaches for estimation of T involve a single natural variable (i.e. flood-peak of a river at a given cross section, the daily maximum discharge, the maximum daily rainfall depth observed at a given rain-gauge). The method of estimation of T entails a frequency analysis of the variable of interest, where the design value of a given T is needed to design the structure of interest (e.g. dams, sewers). In other words, T is used as the index value to set the assigned risk level for the hydraulic works. However, a univariate approach in complex problems ignores the effect of significant variables interrelation leading to different risk levels for each quantity of interest and resulting in a completely wrong estimate of the risk. For example, if one considers the flood inflow in a lake around which cities and villages are positioned, the variable to be investigated in relation to the risk assessment is the lake water level. It is obvious that the same water level may occur from very different flood hydrographs, even when the same initial water level and the same rate curve of outflows are considered. This is a consequence of the interaction of at least three joint
PERIODIC SOLUTIONS FOR A DISCRETE TIME RATIO-DEPENDENT TWO PREDATOR-ONE PREY SYSTEM
Institute of Scientific and Technical Information of China (English)
柏灵; 范猛; 王克
2004-01-01
In this paper, we consider a three-species ratio-dependent predator-prey model governed by difference equations with periodic coefficients. By using the method of coincidence degree, we discuss the existence of positive periodic solutions of this system, a set of easily verifiable sufficient conditions are derived.
Directory of Open Access Journals (Sweden)
Takako eMitsudo
2014-09-01
Full Text Available Brain activity related to time estimation processes in humans was analyzed using a perceptual phenomenon called auditory temporal assimilation. In a typical stimulus condition, two neighboring time intervals (T1 and T2 in this order are perceived as equal even when the physical lengths of these time intervals are considerably different. Our previous event-related potential (ERP study demonstrated that a slow negative component (SNCt appears in the right-frontal brain area (around the F8 electrode after T2, which is associated with judgment of the equality/inequality of T1 and T2. In the present study, we conducted two ERP experiments to further confirm the robustness of the SNCt. The stimulus patterns consisted of two neighboring time intervals marked by three successive tone bursts. Thirteen participants only listened to the patterns in the first session, and judged the equality/inequality of T1 and T2 in the next session. Behavioral data showed typical temporal assimilation. The ERP data revealed that three components (N1; contingent negative variation, CNV; and SNCt emerged related to the temporal judgment. The N1 appeared in the central area, and its peak latencies corresponded to the physical timing of each marker onset. The CNV component appeared in the frontal area during T2 presentation, and its amplitude increased as a function of T1. The SNCt appeared in the right-frontal area after the presentation of T1 and T2, and its magnitude was larger for the temporal patterns causing perceptual inequality. The SNCt was also correlated with the perceptual equality/inequality of the same stimulus pattern, and continued up to about 400 ms after the end of T2. These results suggest that the SNCt can be a signature of equality/inequality judgment, which derives from the comparison of the two neighboring time intervals.
DEFF Research Database (Denmark)
Johansen, Søren Glud; Thorstenson, Anders
2008-01-01
We extend well-known formulae for the optimal base stock of the inventory system with continuous review and constant lead time to the case with periodic review and stochastic, sequential lead times. Our extension uses the notion of the 'extended lead time'. The derived performance measures...
Quantum mechanics of many particles defined on twisted N-enlarged Newton-Hooke space-times
Daszkiewicz, Marcin
2013-01-01
We provide the quantum mechanics of many particles moving in twisted N-enlarged Newton-Hooke space-time. In particular, we consider the example of such noncommutative system - the set of M particles moving in Coulomb field of external point-like source and interacting each other also by Coulomb potential.
Beydogan, Alisa Bahar; Bolkent, Sema
2016-06-01
Ehrlich ascites carcinoma is the one of the animal cancer models having high malignancy and rapid growth resistance. Silibin has reported to be an antioxidant in previous studies. We aimed to investigate the effects of silibin on mouse liver with Ehrlich ascites tumor (EAT) cells in different time periods. Balb/c mice were divided into five groups. Group I (Control): The saline buffer (sb) was injected intraperitoneally (ip) to the mice for 15 days. Group II (Silibin): 150mg/kg silibin was injected ip for 15 days. Group III (Ehrlich): 2×10(5) cells were transferred from the donor mouse to healthy mice on first day. Group IV (Ehrlich+Silibin): Silibin was given between 5th and 15th days to mice inoculated with EAT. Group V (Silibin+Ehrlich): Silibin was injected for 15 days after EAT cells. The liver sections were stained with matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9), caspase 3, caspase 8, and proliferating cell nuclear antigen (PCNA) antibodies by the streptavidin-biotin-peroxidase technique. Biochemical analysis and Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) method were performed in the liver. Superoxide dismutase levels of liver increased in Ehrlich+Silibin group compared with Ehrlich group. Malondialdehyde levels significantly decreased in Silibin+Ehrlich group compared with Ehrlich+Silibin. MMP-2 and MMP-9 immunopositive cells increased in Silibin+Ehrlich compared with Ehrlich group. Caspase 3 and TUNEL signals significantly increased in Silibin+Ehrlich group compared with Ehrlich group. PCNA positive signals significantly increased in Ehrlich+Silibin group compared with Ehrlich group. According to our findings, we suggest that silibin treatment after EAT cells inoculation has more effective than concurrently EAT and silibin treatment. Copyright © 2015 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
Fisher, Sheehan D; Wisner, Katherine L; Clark, Crystal T; Sit, Dorothy K; Luther, James F; Wisniewski, Stephen
2016-10-01
Unipolar and bipolar depression identified in the postpartum period have a heterogeneous etiology. The objectives of this study are to examine the risk factors that distinguish the timing of onset for unipolar and bipolar depression and the associations between depression onset by diagnosis, and general and atypical depressive symptoms. Symptoms of depression were assessed at 4- to 6-weeks postpartum by the Structured Interview Guide for the Hamilton Depression Rating Scale-Atypical Depression Symptoms in an obstetrical sample of 727 women. Data were analyzed using ANOVA, Chi-square, and linear regression. Mothers with postpartum onset of depression were more likely to be older, Caucasian, educated, married/cohabitating, have one or no previous child, and have private insurance in contrast to mothers with pre-pregnancy and prenatal onset of depression. Mothers with bipolar depression were more likely to have a pre-pregnancy onset. Three general and two atypical depressive symptoms distinguished pre-pregnancy, during pregnancy, and postpartum depression onset, and the presence of agitation distinguished between unipolar and bipolar depression. The sample was urban, which may not be generalizable to other populations. The study was cross-sectional, which excludes potential late onset of depression (after 4-6 weeks) in the first postpartum year. A collective set of factors predicted the onset of depression identified in the postpartum for mothers distinguished by episodes of unipolar versus bipolar depression, which can inform clinical interventions. Future research on the onset of major depressive episodes could inform prophylactic and early psychiatric interventions. Copyright © 2016 Elsevier B.V. All rights reserved.
Comparing origins of low-frequency quasi-periodic oscillations with spectral-timing
Stevens, Abigail L.; Uttley, Phil
2017-08-01
The light curves of low-mass X-ray binaries show variability on timescales from milliseconds to months. The rapid (sub-second) variability is particularly interesting because it is thought to probe the inner region of the accretion disk and the central compact object. Observations suggest that different types of low-frequency quasi-periodic oscillations (QPOs) are associated with different emitting-region geometries (e.g., disk-like or jet-like) in the innermost part of the X-ray binary, that are varying possibly due to general relativistic precession. A new way to analyze QPOs is with spectral-timing, which seeks to investigate how matter behaves in the strong gravitational field around the compact object by causally linking the variations from different spectral components. We developed a technique for phase-resolved spectroscopy of QPOs, and are applying it to two types of low-frequency QPOs from the black hole X-ray binary GX 339-4. Over a QPO “period”, we find that the energy spectrum changes not only in normalization, but also in spectral shape. We can quantify how the spectral shape changes as a function of QPO phase, and the two different QPOs show markedly different spectral changes. The "Type B" low-frequency QPO shows evidence of a large-scale-height (jet-like) power-law- emitting precessing region, while in the same outburst the "Type C" low-frequency QPO shows evidence of a small-scale-height (disk-like) power-law-emitting precessing region. These interpretations can be used to look into the evolution of matter in the strong-gravity regime.
DEFF Research Database (Denmark)
Munk-Madsen, Andreas
2005-01-01
"Project" is a key concept in IS management. The word is frequently used in textbooks and standards. Yet we seldom find a precise definition of the concept. This paper discusses how to define the concept of a project. The proposed definition covers both heavily formalized projects and informally...... organized, agile projects. Based on the proposed definition popular existing definitions are discussed....
Directory of Open Access Journals (Sweden)
Xing Yin
2011-01-01
uncertain periodic switched recurrent neural networks with time-varying delays. When uncertain discrete-time recurrent neural network is a periodic system, it is expressed as switched neural network for the finite switching state. Based on the switched quadratic Lyapunov functional approach (SQLF and free-weighting matrix approach (FWM, some linear matrix inequality criteria are found to guarantee the delay-dependent asymptotical stability of these systems. Two examples illustrate the exactness of the proposed criteria.
Period-independent novel circadian oscillators revealed by timed exercise and palatable meals
Danilo E. F. L. Flôres; Crystal N. Bettilyon; Shin Yamazaki
2016-01-01
The mammalian circadian system is a hierarchical network of oscillators organized to optimally coordinate behavior and physiology with daily environmental cycles. The suprachiasmatic nucleus (SCN) of the hypothalamus is at the top of this hierarchy, synchronizing to the environmental light-dark cycle, and coordinates the phases of peripheral clocks. The Period genes are critical components of the molecular timekeeping mechanism of these clocks. Circadian clocks are disabled in Period1/2/3 tri...
Mukherjee, Nibedita; Sutherland, William J; Khan, Md Nabiul I; Berger, Uta; Schmitz, Nele; Dahdouh-Guebas, Farid; Koedam, Nico
2014-06-01
Mangroves are threatened worldwide, and their loss or degradation could impact functioning of the ecosystem. Our aim was to investigate three aspects of mangroves at a global scale: (1) their constituents (2) their indispensable ecological functions, and (3) the maintenance of their constituents and functions in degraded mangroves. We focused on answering two questions: "What is a mangrove ecosystem" and "How vulnerable are mangrove ecosystems to different impacts"? We invited 106 mangrove experts globally to participate in a survey based on the Delphi technique and provide inputs on the three aspects. The outputs from the Delphi technique for the third aspect, i.e. maintenance of constituents and functions were incorporated in a modeling approach to simulate the time frame for recovery. Presented here for the first time are the consensus definition of the mangrove ecosystem and the list of mangrove plant species. In this study, experts considered even monospecific (tree) stands to be a mangrove ecosystem as long as there was adequate tidal exchange, propagule dispersal, and faunal interactions. We provide a ranking of the important ecological functions, faunal groups, and impacts on mangroves. Degradation due to development was identified as having the largest impact on mangroves globally in terms of spatial scale, intensity, and time needed for restoration. The results indicate that mangroves are ecologically unique even though they may be species poor (from the vegetation perspective). The consensus list of mangrove species and the ranking of the mangrove ecological functions could be a useful tool for restoration and management of mangroves. While there is ample literature on the destruction of mangroves due to aquaculture in the past decade, this study clearly shows that more attention must go to avoiding and mitigating mangrove loss due to coastal development (such as building of roads, ports, or harbors).
Bergholt, Mads Sylvest; Lin, Kan; Zheng, Wei; Lau, David Pang Cheng; Huang, Zhiwei
2012-07-01
We report for the first time the implementation of transnasal, image-guided Raman endoscopy to directly assess Raman spectral properties of nasopharyngeal and laryngeal tissue in vivo during clinical endoscopic examinations. A rapid 785-nm excitation Raman endoscopy system, coupled with a miniaturized fiber-optic Raman probe, was utilized for real-time, in vivo Raman measurements of different anatomical locations in the head and neck. A total of 874 high-quality in vivo Raman spectra were successfully acquired from different anatomic locations of the nasopharynx and larynx [i.e., posterior nasopharynx (PN) (n=521), the fossa of Rosenmüller (FOR) (n=157), and true laryngeal vocal chords (LVC) (n=196)] in 23 normal subjects at transnasal endoscopy. Difference spectra and principal component analysis (PCA) were employed for tissue characterization, uncovering the tissue variability at the biomolecular level. The PCA-linear discriminant analysis (LDA) provides sensitivity of 77.0% and specificity of 89.2% for differentiation between PN and FOR, and sensitivity of 68.8% and specificity of 76.0% for distinguishing LVC and PN using the leave-one-subject-out, cross-validation method. This work demonstrates that transnasal, image-guided Raman endoscopy can be used to acquire in vivo Raman spectra from the nasopharynx and larynx in real time. Significant Raman spectral differences (p<0.05) identified as reflecting the distinct composition and morphology in the nasopharynx and larynx should be considered to be important parameters in the interpretation and rendering of diagnostic decision algorithms for in vivo tissue diagnosis and characterization in the head and neck.
Jhun, Hyung-Joon; Kim, Ho; Cho, Sung-Il
2011-05-01
We examined time trend and age-period-cohort effects on acute myocardial infarction (AMI) mortality in Korean adults from 1988 to 2007. Annual AMI mortality data and population statistics from 1988 to 2007 were obtained from the STATISTICS KOREA website. Age adjusted mortality for four 5-yr calendar periods (1988-1992 to 2003-2007) was calculated by direct standardization using the Year 2000 WHO world standard population. A log-linear Poisson regression model was used to estimate age, period, and cohort effects on AMI mortality. In both genders, age-adjusted AMI mortality increased from period one (1988-1992) to period three (1998-2002) but decreased in period four (2003-2007). An exponential age effect was noted in both genders. The rate ratio of the cohort effect increased up to the 1943 birth cohort and decreased gradually thereafter, and the rate ratio of the period effect increased up to period three (1998-2002) and decreased thereafter. Our results suggest that AMI mortality in Korean adults has decreased since the period 1998-2002 and age, period, and cohort effects have influenced on AMI mortality.
Magnetic Cycles and Rotation Periods of Late Type Stars from photometric time series
Mascareño, A Suárez; Hernández, J I González
2016-01-01
We investigate the photometric modulation induced by magnetic activity cycles and study the relationship between rotation period and activity cycle(s) in late-type (FGKM) stars. We analyse light-curves spanning up to 9 years of 125 nearby stars provided by the ASAS survey. The sample is mainly conformed by low-activity main sequence late A to mid M-type stars. A search is performed for short (days) and long-term (years) periodic variations in the photometry. We modelled with combinations of sinusoids the light-curves to measure the properties of these periodic signals. To provide a better statistical interpretation of our results we complement them with the results from previous similar works. We have been able to measure long-term photometric cycles of 47 stars. Rotational modulation was also detected and rotational periods measured in 36 stars. For 28 stars we have simultaneous measurements of both, activity cycles and rotational periods, being 17 of them M-type stars. From sinusoidal fits we measured both ...
DEFF Research Database (Denmark)
Johansen, Søren Glud; Thorstenson, Anders
We show that well-known textbook formulae for determining the optimal base stock of the inventory system with continuous review and constant lead time can easily be extended to the case with periodic review and stochastic, sequential lead times. The provided performance measures and conditions...
2010-10-01
... 45 Public Welfare 2 2010-10-01 2010-10-01 false What time frames and guidelines apply regarding the obligation and liquidation periods for NEW Program funds? 287.55 Section 287.55 Public Welfare... NEW Program Funding § 287.55 What time frames and guidelines apply regarding the obligation and...
DEFF Research Database (Denmark)
Johansen, Søren Glud; Thorstenson, Anders
2008-01-01
We extend well-known formulae for the optimal base stock of the inventory system with continuous review and constant lead time to the case with periodic review and stochastic, sequential lead times. Our extension uses the notion of the ‘extended lead time’. The derived performance measures...
DEFF Research Database (Denmark)
Johansen, Søren Glud; Thorstenson, Anders
2008-01-01
We extend well-known formulae for the optimal base stock of the inventory system with continuous review and constant lead time to the case with periodic review and stochastic, sequential lead times. Our extension uses the notion of the ‘extended lead time’. The derived performance measures...
Zhao, Yongli; Li, Yajie; Wang, Xinbo; Chen, Bowen; Zhang, Jie
2016-09-01
A hierarchical software-defined networking (SDN) control architecture is designed for multi-domain optical networks with the Open Daylight (ODL) controller. The OpenFlow-based Control Virtual Network Interface (CVNI) protocol is deployed between the network orchestrator and the domain controllers. Then, a dynamic bandwidth on demand (BoD) provisioning solution is proposed based on time scheduling in software-defined multi-domain optical networks (SD-MDON). Shared Risk Link Groups (SRLG)-disjoint routing schemes are adopted to separate each tenant for reliability. The SD-MDON testbed is built based on the proposed hierarchical control architecture. Then the proposed time scheduling-based BoD (Ts-BoD) solution is experimentally demonstrated on the testbed. The performance of the Ts-BoD solution is evaluated with respect to blocking probability, resource utilization, and lightpath setup latency.
Cycle slipping in nonlinear circuits under periodic nonlinearities and time delays
Smirnova, Vera; Proskurnikov, Anton; Utina, Natalia V.
2014-01-01
Phase-locked loops (PLL), Costas loops and other synchronizing circuits are featured by the presence of a nonlinear phase detector, described by a periodic nonlinearity. In general, nonlinearities can cause complex behavior of the system such multi-stability and chaos. However, even phase locking ma
Institute of Scientific and Technical Information of China (English)
Yao-lin Jiang
2003-01-01
In this paper we presented a convergence condition of parallel dynamic iteration methods for a nonlinear system of differential-algebraic equations with a periodic constraint.The convergence criterion is decided by the spectral expression of a linear operator derivedfrom system partitions. Numerical experiments given here confirm the theoretical work ofthe paper.
Directory of Open Access Journals (Sweden)
Yingwei Li
2013-01-01
Full Text Available The global exponential stability issues are considered for almost periodic solution of the neural networks with mixed time-varying delays and discontinuous neuron activations. Some sufficient conditions for the existence, uniqueness, and global exponential stability of almost periodic solution are achieved in terms of certain linear matrix inequalities (LMIs, by applying differential inclusions theory, matrix inequality analysis technique, and generalized Lyapunov functional approach. In addition, the existence and asymptotically almost periodic behavior of the solution of the neural networks are also investigated under the framework of the solution in the sense of Filippov. Two simulation examples are given to illustrate the validity of the theoretical results.
Formulation of a Combined Transportation and Inventory Optimization Model with Multiple Time Periods
Directory of Open Access Journals (Sweden)
G.Krishnakumari,
2016-03-01
Full Text Available Most distribution network design models existing in the literature have focused on minimizing the costs of inventory and transportation. During the analysis of supply chain of currency management problem it is observed that the transportation of currency from various sources to various destinations and the required inventory to be maintained to meet the emerging demands requires formulation of a combined problem. This framework aims to support the coordination of inventory and transportation activities to properly manage the inventory profiles and currency flows between source locations and distribution centers. This paper considers a multi-period inventory and transportation model for a single commodity. The key contribution of this paper is, a mathematical programming formulation of transportation cum inventory problem is proposed and an algorithm for this new formulation as a multi period decision process is intended. A numerical example of currency transportation cum inventory is presented to illustrate the proposed algorithm
Napp, Diego; Shankar, Shiva
2010-01-01
This paper studies behaviors that are defined on a torus, or equivalently, behaviors defined in spaces of periodic functions, and establishes their basic properties analogous to classical results of Malgrange, Palamodov, Oberst et al. for behaviors on R^n. These properties - in particular the Nullstellensatz describing the Willems closure - are closely related to integral and rational points on affine algebraic varieties.
Napp, Diego; Put, Marius van der; Shankar, Shiva
2010-01-01
This paper studies behaviors that are defined on a torus, or equivalently, behaviors defined in spaces of periodic functions, and establishes their basic properties analogous to classical results of Malgrange, Palamodov, Oberst et al. for behaviors on R(n). These properties-in particular the Nullste
Kamimori, Gary H.; McLellan, Tom M.; Tate, Charmaine M.; Voss, David M.; Niro, Phil; Lieberman, Harris R.
2014-01-01
Rationale Various occupational groups are required to maintain optimal physical and cognitive function during overnight periods of wakefulness, often with less than optimal sleep. Strategies are required to help mitigate the impairments in cognitive function to help sustain workplace safety and productivity. Objectives To test the effectiveness of repeated 200 mg doses of caffeine on cognitive function and live-fire marksmanship with soldiers during three successive nights of sustained wakefu...
PERIODIC SOLUTIONS FOR GENERALIZED PREDATOR-PREY SYSTEMS WITH TIME DELAY AND DIFFUSION
Institute of Scientific and Technical Information of China (English)
李必文
2004-01-01
A set of easily verifiable sufficient conditions are derived for the existence of positive periodic solutions for delayed generalized predator-prey dispersion system x'1 (t) = x1 (t)g1 (t, x1 (t) ) - a1 (t)y(t)p1 (x1 (t) ) + D1 (t)(x2(t) - x1 (t) ),x'2 (t) = x2 (t)g2 (t, x2 (t) ) - a2 (t)y(t)p2 (x2 (t) ) + D2(t)(x1 (t) - x2 (t)),y' (t) = y(t) {-h(t, y(t) ) + b1 (t)p1 (x1 (t - τ1 ) ) + b2(t)p2(x2(t - τ2))],where ai(t), bi(t) and Di(t)(i = 1, 2) are positive continuous T-periodic functions, gi(t, xi)(i = 1,2) and h(t,y) are continuous and T-periodic with respect to t and h(t,y) ＞ 0 for y ＞ 0, t, y ∈ R, pi(x)(i = 1, 2) are continuous and monotonously increasing functions, and pi(xi) ＞ 0 for xi ＞ 0.
Periodic Solution of a Nonautonomous Diffusive Food Chain System of Three Species with Time Delays
Institute of Scientific and Technical Information of China (English)
Zheng-qiu Zhang; Xian-wu Zeng; Zhi-cheng Wang
2003-01-01
By using the continuation theorem of coincidence degree theory, the existence of a positive periodic solution for a nonautonomous diffusive food chain system of three species.dx1(t)/dt = xl(t)[r1(t) - a11(t)x1(t) - a12(t)x2(t)] + D1(t)[y(t) - x1(t)],dx2 (t)/dt = x2(t)[-r2(t) + a21(t)x1(t - τ1) - a22(t)x2(t) - a23(t)x3(t)],dx3 (t)/dt = x3(t)[-r3(t) + a32(t)x2(t - τ2) - a33(t)x3(t)],dy(t)/dt = y(t)[r4(t) - a44(t)y(t)] + D2(t)[x1 (t) - y(t)],is established, where ri(t), aii(t) (i= 1, 2, 3, 4), Di(t) (i = 1, 2), a12(t), a21 (t), a23(t) and a32(t) are all positive periodic continuous functions with period w ＞ 0, τi(i = 1, 2) are positive constants.
Li, Fang; Liang, Xing; Shen, Wenxian
2016-08-01
In this series of papers, we investigate the spreading and vanishing dynamics of time almost periodic diffusive KPP equations with free boundaries. Such equations are used to characterize the spreading of a new species in time almost periodic environments with free boundaries representing the spreading fronts. In the first part of the series, we showed that a spreading-vanishing dichotomy occurs for such free boundary problems (see [16]). In this second part of the series, we investigate the spreading speeds of such free boundary problems in the case that the spreading occurs. We first prove the existence of a unique time almost periodic semi-wave solution associated to such a free boundary problem. Using the semi-wave solution, we then prove that the free boundary problem has a unique spreading speed.
Li, Bing; Li, Yongkun; Zhang, Xuemei
2016-01-01
In this paper, by using the existence of the exponential dichotomy of linear dynamic equations on time scales and the theory of calculus on time scales, we study the existence and global exponential stability of periodic solutions for a class of n-dimensional neutral dynamic equations on time scales. We also present an example to illustrate the feasibility of our results. The results of this paper are completely new and complementary to the previously known results even in both the case of differential equations (time scale [Formula: see text]) and the case of difference equations (time scale [Formula: see text]).
Institute of Scientific and Technical Information of China (English)
FAN JianXing; YANG HuaZhong; WANG Hui; YAN XiaoLang; HOU ChaoHuan
2007-01-01
Phase noise analysis of an oscillator is implemented with its periodic time-varying small signal state equations by perturbing the autonomous large signal state equations of the oscillator. In this paper, the time domain steady solutions of oscillators are perturbed with traditional regular method; the periodic time-varying Jocobian modulus matrices are decomposed with Sylvester theorem, and on the resulting space spanned by periodic vectors, the conditions under which the oscillator holds periodic steady states with any perturbations are analyzed. In this paper, stochastic calculus is applied to disclose the generation process of phase noise and calculate the phase jitter of the oscillator by injecting a pseudo sinusoidal signal in frequency domain, representing the white noise, and a δ correlation signal in time domain into the oscillator. Applying the principle of frequency modulation, we learned how the power-law and the Lorentzian spectrums are formed. Their relations and the Lorentzian spectrums of harmonics are also worked out. Based on the periodic Jacobian modulus matrix, the simple algorithms for Floquet exponents and phase noise are constructed, as well as a simple case is demonstrated. The analysis difficulties and the future directions for the phase noise of oscillators are also pointed out at the end.
Lewis, Simon; Maslin, Mark
2016-04-01
Time is divided by geologists according to marked shifts in Earth's state. Recent global environmental changes suggest that Earth may have entered a new human-dominated geological epoch, the Anthropocene. Should the Anthropocene - the idea that human activity is a force acting upon the Earth system in ways that mean that Earth will be altered for millions of years - be defined as a geological time-unit at the level of an Epoch? Here we appraise the data to assess such claims, first in terms of changes to the Earth system, with particular focus on very long-lived impacts, as Epochs typically last millions of years. Can Earth really be said to be in transition from one state to another? Secondly, we then consider the formal criteria used to define geological time-units and move forward through time examining whether currently available evidence passes typical geological time-unit evidence thresholds. We suggest two time periods likely fit the criteria (1) the aftermath of the interlinking of the Old and New Worlds, which moved species across continents and ocean basins worldwide, a geologically unprecedented and permanent change, which is also the globally synchronous coolest part of the Little Ice Age (in Earth system terms), and the beginning of global trade and a new socio-economic "world system" (in historical terms), marked as a golden spike by a temporary drop in atmospheric CO2, centred on 1610 CE; and (2) the aftermath of the Second World War, when many global environmental changes accelerated and novel long-lived materials were increasingly manufactured, known as the Great Acceleration (in Earth system terms) and the beginning of the Cold War (in historical terms), marked as a golden spike by the peak in radionuclide fallout in 1964. We finish by noting that the Anthropocene debate is politically loaded, thus transparency in the presentation of evidence is essential if a formal definition of the Anthropocene is to avoid becoming a debate about bias. The
THE SURVIVAL PROBABILITY IN FINITE TIME PERIOD IN FULLY DISCRETE RISK MODEL
Institute of Scientific and Technical Information of China (English)
ChengShixue; WuBiao
1999-01-01
The probabilities of the following events are first discussed in this paper: the insurance company survives to any fixed time k and the surplus at time k equals x≥1. The formulas for calculating such probabilities are deduced through analytical and probabilistic arguments respectively. Finally, other probability laws relating to risk are determined based on the probabilities mentioned above.
McKay, Michael T.; Cole, Jon C.; Sumnall, Harry R.; Goudie, Andrew J.
2012-01-01
Time perspective is a cognitive-motivational construct, which has been shown to be related to decision-making, motivation and adjustment. The majority of research into time perspective has been conducted in college students and/or general population samples. Focus groups were held as part of a larger investigation into the relationship between…
The time-periodic diffusive competition models with a free boundary and sign-changing growth rates
Wang, Mingxin; Zhang, Yang
2016-10-01
To understand the spreading of invasive and native species, in this paper we consider the diffusive competition models with a free boundary in the heterogeneous time-periodic environments, in which the variable intrinsic growth rates of these two species change signs and may be very negative in some large regions. We study the spreading-vanishing dichotomy, long-time dynamical behavior of solution, sharp criteria for spreading and vanishing, and estimates of the asymptotic spreading speed of the free boundary. Moreover, we establish the existence of positive solutions to a T-periodic boundary value problem of the diffusive competition system with sign-changing growth rates in the half line.
Time-periodic solutions of massive scalar fields in AdS background: perturbative constructions
Kim, Nakwoo
2014-01-01
We consider scalar fields which are coupled to Einstein gravity with a negative cosmological constant, and construct periodic solutions perturbatively. In particular, we study tachyonic scalar fields whose mass is at or above the Breitenlohner-Freedman bound in four, five, and seven spacetime dimensions. The critical amplitude of the leading order perturbation, for which the perturbative expansion breaks down, increases as we consider less massive fields. We present various examples including a model with a self-interacting scalar field which is derived from a consistent truncation of IIB supergravity.
Detection of the Long Period Long Duration (LPLD) Events in Time- and Frequency-Domain
Kwietniak, Anna
2015-02-01
Long Period Long Duration (LPLD) signals are unusual seismic events that can be observed during hydraulic fracturing. These events are very similar in appearance to tectonic tremors sequences, which were first observed in subduction zones. Their nature is not well known. LPLD might be related to the productivity of the reservoir. Different methods of the LPLD events' detection recorded during hydraulic fracturing are presented. The author applied two methods for LPLD detection-Butterworth filtering and Continuous Wavelet Transform (CWT). Additionally, a new approach to LPLD events detection-instantaneous seismic attributes-was used, common in a classical seismic interpretation but not in microseismic monitoring.
Energy Technology Data Exchange (ETDEWEB)
Kim, Nakwoo, E-mail: nkim@khu.ac.kr
2015-03-06
We consider scalar fields which are coupled to Einstein gravity with a negative cosmological constant, and construct periodic solutions perturbatively. In particular, we study tachyonic scalar fields whose mass is at or above the Breitenlohner–Freedman bound in four, five, and seven spacetime dimensions. The critical amplitude of the leading order perturbation, for which the perturbative expansion breaks down, increases as we consider less massive fields. We present various examples including a model with a self-interacting scalar field which is derived from a consistent truncation of IIB supergravity.
Khalifa, Marwa Ahmed; Rateb, Sherif Abdel-Razzak; El-Bahrawy, Khalid Ahmed
2016-04-01
The current investigation aimed to establish a fixed-time induction of ovulation/ insemination protocol in camels superovulated by different equine chorionic gonadotropin (eCG) regimens during the transition period in Egypt (mid-October to mid-November). Seventeen pluriparous camels, Camelus dromedarius, were used. All females retained controlled intra-vaginal drug releasers (CIDRs) for 13 consecutive days, and at CIDR withdrawal, the camels were randomly divided into three groups. The control group (n = 5) received 1 ml saline intra-muscularly (i.m.), whereas remaining camels were superovulated by 2500 IU eCG either in a single shot (SS, n = 6) or in serial decreasing doses over 3 days (DD, n = 6). Ovarian dynamics were monitored by transrectal ultrasonography at 2-day intervals, and ovulation was induced by 5000 IU hCG i.m. The changes in reproductive hormones throughout the period of the study were determined. The results showed that mean values of total no. of follicles and size of dominant follicles remained low (P superovulated groups compared to the control, where the dominant follicles attained the highest (P 25 mm), which did not respond to induction to ovulation. These results elucidate that eCG administration in serial decreasing doses generates a reliable superovulatory response in camels, and ovulation can be blindly induced 12 days after the gonadotropin treatment. This fixed-time hormonal protocol represents a sufficient alternative to conventional day-to-day ultrasonography and would have profound implication for enhanced fertility in dromedary camels by facilitating infield application of embryo transfer technique.
Directory of Open Access Journals (Sweden)
Santhi Baskaran
2010-12-01
Full Text Available Energy consumption is a critical design issue in real-time systems, especially in battery- operated systems. Maintaining high performance, while extending the battery life between charges is an interesting challenge for system designers. Dynamic Voltage Scaling (DVS allows a processor to dynamically change speed and voltage at run time, thereby saving energy by spreading run cycles into idle time.Knowing when to use full power and when not, requires the cooperation of the operating system scheduler. Usually, higher processor voltage and frequency leads to higher system throughput whileenergy reduction can be obtained using lower voltage and frequency. Instead of lowering processorvoltage and frequency as much as possible, energy efficient real-time scheduling adjusts voltage andfrequency according to some optimization criteria, such as low energy consumption or high throughput,while it meets the timing constraints of the real-time tasks. As the quantity and functional complexity ofbattery powered portable devices continues to raise, energy efficient design of such devices has becomeincreasingly important. Many real-time scheduling algorithms have been developed recently to reduceenergy consumption in the portable devices that use DVS capable processors. Extensive power awarescheduling techniques have been published for energy reduction, but most of them have been focusedsolely on reducing the processor energy consumption. While the processor is one of the major powerhungry units in the system, other peripherals such as network interface card, memory banks, disks alsoconsume significant amount of power. Dynamic Power Down (DPD technique is used to reduce energyconsumption by shutting down the processing unit and peripheral devices, when the system is idle. Threealgorithms namely Red Tasks Only (RTO, Blue When Possible (BWP and Red as Late as Possible (RLPare proposed in the literature to schedule the real-time tasks in Weakly-hard real-time
Advantages and Drawbacks of Applying Periodic Time-Variant Modal Analysis to Spur Gear Dynamics
DEFF Research Database (Denmark)
Pedersen, Rune; Santos, Ilmar; Hede, Ivan Arthur
2010-01-01
A simplified torsional model with a reduced number of degrees-of-freedom is used in order to investigate the potential of the technique. A time-dependent gear mesh stiffness function is introduced and expanded in a Fourier series. The necessary number of Fourier terms is determined in order...... to ensure sufficient accuracy of the results. The method of time-variant modal analysis is applied, and the changes in the fundamental and the parametric resonance frequencies as a function of the rotational speed of the gears, are found. By obtaining the stationary and parametric parts of the time...
Zu, Penghe; Chen, Long; Xin, Jack
2015-09-01
The minimal speeds (c∗) of the Kolmogorov-Petrovsky-Piskunov (KPP) fronts at small diffusion (ɛ ≪ 1) in a class of time-periodic cellular flows with chaotic streamlines is investigated in this paper. The variational principle of c∗ reduces the computation to that of a principle eigenvalue problem on a periodic domain of a linear advection-diffusion operator with space-time periodic coefficients and small diffusion. To solve the advection dominated time-dependent eigenvalue problem efficiently over large time, a combination of spectral methods and finite element, as well as the associated fast solvers, are utilized to accelerate computation. In contrast to the scaling c∗ = O(ɛ 1 / 4) in steady cellular flows, a new relation c∗ = O(1) as ɛ ≪ 1 is revealed in the time-periodic cellular flows due to the presence of chaotic streamlines. Residual propagation speed emerges from the Lagrangian chaos which is quantified as a sub-diffusion process.
Space-time kriging of precipitation variability in Turkey for the period 1976-2010
Raja, Nussaïbah B.; Aydin, Olgu; Türkoğlu, Necla; Çiçek, Ihsan
2017-07-01
The purpose of this study is to revaluate the changing spatial and temporal trends of precipitation in Turkey. Turkey is located in one of the regions at greatest risk from the potential effects of climate change. Since the 1970s, a decreasing trend in annual precipitation has been observed, in addition to an increasing number of precipitation-related natural hazards such as floods, extreme precipitation, and droughts. An understanding of the temporal and spatial characteristics of precipitation is therefore crucial to hazard management as well as planning and managing water resources, which depend heavily on precipitation. The ordinary kriging method was employed to interpolate precipitation estimates using precipitation records from 228 meteorological stations across the country for the period 1976-2010. A decreasing trend was observed across the Central Anatolian region, except for 1996-2000 which saw an increase in precipitation. However, this same period is identified as the driest year in Eastern and South Eastern Anatolia. The Eastern Black Sea region has the highest precipitation in the country; after 1996, an increase in annual precipitation in this region is observed. An overall reduction is also seen in southwest Turkey, with less variation in precipitation.
Space-time kriging of precipitation variability in Turkey for the period 1976-2010
Raja, Nussaïbah B.; Aydin, Olgu; Türkoğlu, Necla; Çiçek, Ihsan
2016-03-01
The purpose of this study is to revaluate the changing spatial and temporal trends of precipitation in Turkey. Turkey is located in one of the regions at greatest risk from the potential effects of climate change. Since the 1970s, a decreasing trend in annual precipitation has been observed, in addition to an increasing number of precipitation-related natural hazards such as floods, extreme precipitation, and droughts. An understanding of the temporal and spatial characteristics of precipitation is therefore crucial to hazard management as well as planning and managing water resources, which depend heavily on precipitation. The ordinary kriging method was employed to interpolate precipitation estimates using precipitation records from 228 meteorological stations across the country for the period 1976-2010. A decreasing trend was observed across the Central Anatolian region, except for 1996-2000 which saw an increase in precipitation. However, this same period is identified as the driest year in Eastern and South Eastern Anatolia. The Eastern Black Sea region has the highest precipitation in the country; after 1996, an increase in annual precipitation in this region is observed. An overall reduction is also seen in southwest Turkey, with less variation in precipitation.
Existence of the time periodic solution for damped Schroedinger-Boussinesq equation
Institute of Scientific and Technical Information of China (English)
BolingGUO; XianyunDU
2000-01-01
In this paper, we study the time priodic solution for the weakly damped Schroedinger-Boussinesq equation, by Galerkin method, and prove the existence and uniqueness of the equations under some appropriate conditions.
Lorimer, D R; Manchester, R N; Possenti, A; Lyne, A G; McLaughlin, M A; Kramer, M; Hobbs, G; Stairs, I H; Burgay, M; Eatough, R P; Keith, M J; Faulkner, A J; D'Amico, N; Camilo, F; Corongiu, A; Crawford, F
2015-01-01
We present timing observations of four millisecond pulsars discovered in the Parkes 20-cm multibeam pulsar survey of the Galactic plane. PSRs J1552-4937 and J1843-1448 are isolated objects with spin periods of 6.28 and 5.47 ms respectively. PSR J1727-2946 is in a 40-day binary orbit and has a spin period of 27 ms. The 4.43-ms pulsar J1813-2621 is in a circular 8.16-day binary orbit around a low-mass companion star with a minimum companion mass of 0.2 solar masses. Combining these results with detections from five other Parkes multibeam surveys, gives a well-defined sample of 56 pulsars with spin periods below 20 ms. We develop a likelihood analysis to constrain the functional form which best describes the underlying distribution of spin periods for millisecond pulsars. The best results were obtained with a log-normal distribution. A gamma distribution is less favoured, but still compatible with the observations. Uniform, power-law and Gaussian distributions are found to be inconsistent with the data. Galactic...
Steady-state time-periodic finite element analysis of a brushless DC motor drive considering motion
Directory of Open Access Journals (Sweden)
Jagieła Mariusz
2015-09-01
Full Text Available This paper aims at providing a framework for comprehensive steady-state time-domain analysis of rotating machines considering motion. The steady-state waveforms of electromagnetic and circuit quantities are computed via iterative solution of the nonlinear field-circuit-and-motion problem with constraints of time periodicity. The cases with forced speed and forced load torque are considered. A comparison of execution times with a conventional time-stepping transient model is carried out for two different machines. The numerical stability of a time-periodic model with forced speed is shown to be worse than that of traditional transient time-stepping one, although the model converges within a reasonable number of iterations. This is not the case if forced load via equation of mechanical balance is accounted for. To ensure convergence of the iterative process the physical equation of motion is replaced by the fixed-point equation. In this way the model delivers time-periodic solutions regarding not only the electromagnetic quantities but also the rotational speed.
Directory of Open Access Journals (Sweden)
Ling Zhang
2012-01-01
Full Text Available We study a multi-period mean-variance portfolio selection problem with an uncertain time horizon and serial correlations. Firstly, we embed the nonseparable multi-period optimization problem into a separable quadratic optimization problem with uncertain exit time by employing the embedding technique of Li and Ng (2000. Then we convert the later into an optimization problem with deterministic exit time. Finally, using the dynamic programming approach, we explicitly derive the optimal strategy and the efficient frontier for the dynamic mean-variance optimization problem. A numerical example with AR(1 return process is also presented, which shows that both the uncertainty of exit time and the serial correlations of returns have significant impacts on the optimal strategy and the efficient frontier.
Errors in visuo-haptic and haptic-haptic location matching are stable over long periods of time.
Kuling, Irene A; Brenner, Eli; Smeets, Jeroen B J
2016-05-01
People make systematic errors when they move their unseen dominant hand to a visual target (visuo-haptic matching) or to their other unseen hand (haptic-haptic matching). Why they make such errors is still unknown. A key question in determining the reason is to what extent individual participants' errors are stable over time. To examine this, we developed a method to quantify the consistency. With this method, we studied the stability of systematic matching errors across time intervals of at least a month. Within this time period, individual subjects' matches were as consistent as one could expect on the basis of the variability in the individual participants' performance within each session. Thus individual participants make quite different systematic errors, but in similar circumstances they make the same errors across long periods of time. Copyright © 2016 Elsevier B.V. All rights reserved.
Pork meat matured for different periods of time in vacuum-packaging system
Directory of Open Access Journals (Sweden)
Marina Avena Tarsitano
2014-02-01
Full Text Available The objective of this study was to evaluate the quality of pork meat when matured. The treatments evaluated were: meat no maturated; meat matured for 3 days; meat matured for 6 days. The pH, water loss percentage, and liquid lost in thawing displayed a decreasing linear regression while the fluid lost in cooking showed an increasing linear regression. The L*, a*, b* and chroma showed an increasing linear effect while the tone displayed a decreasing linear regression. The mesophilic and psychrotrophic bacteria counts were greater for the treatments that underwent maturation. The shear force decrease linearly with the increase in the maturation period. The MFI, lipid oxidation, and sensory analyses were not affected by treatments. The maturation of the pork meat improved the color, reduced the pH and increased the tenderness. There was no change in the lipid stability of the meat, nor sensory damage.
Wierzcholski, Krzysztof
2014-01-01
The present paper is concerned with the calculation of the human hip joint parameters for periodic, stochastic unsteady, motion with asymmetric probability density function for gap height. The asymmetric density function indicates that the stochastic probabilities of gap height decreasing are different in comparison with the probabilities of the gap height increasing. The models of asymmetric density functions are considered on the grounds of experimental observations. Some methods are proposed for calculation of pressure distributions and load carrying capacities for unsteady stochastic conditions in a super thin layer of biological synovial fluid inside the slide biobearing gap limited by a spherical bone acetabulum. Numerical calculations are performed in Mathcad 12 Professional Program, by using the method of finite differences. This method assures stability of numerical solutions of partial differential equations and gives proper values of pressure and load carrying capacity forces occurring in human hip joints.
Directory of Open Access Journals (Sweden)
Nujaba Binte Kabir
2012-06-01
Full Text Available The Features of the Chinese wood frame buildings are same in character from dynasty to dynasty. The study concentrates on 9 Chinese wood frame buildings from Tang to Yuan dynasty and tries to relate these buildings with the text described in a building manual book published in Song dynasty Yingzao fashi. The features of some buildings match with the text described in the book some do not. But on the other hand Liang Sicheng, scholar of Chinese architecture in his book claimed that Chinese wood frame architecture has a unique system of characteristics (Liang, 1984. The system of wood frame Chinese architecture did not change but the proportion of the features has changed in different dynasty. The aim of the paper is to compare the features of the buildings those have been studied according to Yingzao fashi with Liang's observation on the change of building style in different periods.
Yasui, Takeshi; Hsieh, Yi-Da; Sakaguchi, Yoshiyuki; Hindle, Francis; Yokoyama, Shuko; Araki, Tsutomu; Hashimoto, Mamoru
2014-01-01
Fourier transform spectroscopy (FTS) has been widely used in a variety of fields in research, industry, and medicine due to its high signal-to-noise ratio, simultaneous acquisition of signals in a broad spectrum, and versatility for different radiation sources. Further improvement of the spectroscopic performance will widen its scope of applications. Here, we demonstrate improved spectral resolution by overcoming the time window limitation using discrete Fourier transform spectroscopy (dFTS) with precisely periodic pulsed terahertz (THz) radiation. Since infinitesimal resolution can be achieved at periodically discrete frequencies when the time window size is exactly matched to the repetition period T, a combination of THz-dFTS with a spectral interleaving technique achieves a spectral resolution only limited by the spectral interleaving interval. Linewidths narrower than 1/(50T) are fully resolved allowing the attribution of rotational-transition absorption lines of low-pressure molecular gases within a 1.25...
Periodic Solutions for a Semi-Ratio-Dependent Predator-Prey System with Delays on Time Scales
Directory of Open Access Journals (Sweden)
Xiaoquan Ding
2012-01-01
Full Text Available This paper is devoted to the existence of periodic solutions for a semi-ratio-dependent predator-prey system with time delays on time scales. With the help of a continuation theorem based on coincidence degree theory, we establish necessary and sufficient conditions for the existence of periodic solutions. Our results show that for the most monotonic prey growth such as the logistic, the Gilpin, and the Smith growth, and the most celebrated functional responses such as the Holling type, the sigmoidal type, the Ivlev type, the Monod-Haldane type, and the Beddington-DeAngelis type, the system always has at least one periodic solution. Some known results are shown to be special cases of the present paper.
Tunmer, William; Greaney, Keith
2010-01-01
In 2007, the New Zealand Ministry of Education formally recognized the condition of dyslexia for the first time and has subsequently developed a working definition of the condition. The aim of this article is to draw on contemporary theory and research on reading development, reading difficulties, and reading intervention to describe what the…
Lunar periodicity and the timing of river entry in Atlantic salmon Salmo salar.
Kuparinen, A; O'Hara, R B; Merilä, J
2009-07-01
Historical catch records of Atlantic salmon Salmo salar from three rivers discharging to the Baltic Sea in an area free from tides and from strong effects of the moon on illumination were analysed to investigate whether timing of S. salar river entry was associated with lunar cycles directly. Although a significant effect of lunar phase on river entry was detected, with more fish entering rivers around the full moon than other phases, the effect of the lunar cycle was very small compared with other sources of variation. Hence, the biological role of lunar cycle as a determinant of the timing of S. salar runs in the investigated populations was negligible, suggesting that lunar cycle per se does not play a role in the timing of S. salar river entry.
30 CFR 250.1161 - When may I flare or vent gas for extended periods of time?
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may I flare or vent gas for extended... Production Requirements Flaring, Venting, and Burning Hydrocarbons § 250.1161 When may I flare or vent gas... flare or vent gas for an extended period of time. The Regional Supervisor will specify the approved...
Directory of Open Access Journals (Sweden)
Kwadwo S. Agyepong
2013-01-01
Full Text Available Time-course expression profiles and methods for spectrum analysis have been applied for detecting transcriptional periodicities, which are valuable patterns to unravel genes associated with cell cycle and circadian rhythm regulation. However, most of the proposed methods suffer from restrictions and large false positives to a certain extent. Additionally, in some experiments, arbitrarily irregular sampling times as well as the presence of high noise and small sample sizes make accurate detection a challenging task. A novel scheme for detecting periodicities in time-course expression data is proposed, in which a real-valued iterative adaptive approach (RIAA, originally proposed for signal processing, is applied for periodogram estimation. The inferred spectrum is then analyzed using Fisher’s hypothesis test. With a proper -value threshold, periodic genes can be detected. A periodic signal, two nonperiodic signals, and four sampling strategies were considered in the simulations, including both bursts and drops. In addition, two yeast real datasets were applied for validation. The simulations and real data analysis reveal that RIAA can perform competitively with the existing algorithms. The advantage of RIAA is manifested when the expression data are highly irregularly sampled, and when the number of cycles covered by the sampling time points is very reduced.
Kim, M.; Harman, C. J.
2013-12-01
The distribution of water travel times is one of the crucial hydrologic characteristics of the catchment. Recently, it has been argued that a rigorous treatment of travel time distributions should allow for their variability in time because of the variable fluxes and partitioning of water in the water balance, and the consequent variable storage of a catchment. We would like to be able to observe the structure of the temporal variations in travel time distributions under controlled conditions, such as in a soil column or under irrigation experiments. However, time-variable travel time distributions are difficult to observe using typical active and passive tracer approaches. Time-variability implies that tracers introduced at different times will have different travel time distributions. The distribution may also vary during injection periods. Moreover, repeat application of a single tracer in a system with significant memory leads to overprinting of break-through curves, which makes it difficult to extract the original break-through curves, and the number of ideal tracers that can be applied is usually limited. Recognizing these difficulties, the PERTH (PERiodic Tracer Hierarchy) method has been developed. The method provides a way to estimate time-variable travel time distributions by tracer experiments under controlled conditions by employing a multi-tracer hierarchy under periodical hydrologic forcing inputs. The key assumption of the PERTH method is that as time gets sufficiently large relative to injection time, the average travel time distribution of two distinct ideal tracers injected during overlapping periods become approximately equal. Thus one can be used as a proxy for the other, and the breakthrough curves of tracers applied at different times in a periodic forcing condition can be separated from one another. In this study, we tested the PERTH method numerically for the case of infiltration at the plot scale using HYDRUS-1D and a particle
Kruger, A T; Wasserman, I M; Kruger, Adam T.; Loredo, Thomas J.; Wasserman, Ira
2002-01-01
We analyze the Time-Tagged Event (TTE) data from observations of gamma ray bursts (GRBs) and soft gamma repeaters (SGRs) by the Burst and Transient Source Experiment (BATSE). These data provide the best available time resolution for GRBs and SGRs. We have performed an extensive search for weak periodic signals in the frequency range 400 Hz to 2500 Hz using the burst records for 2203 GRBs and 152 SGR flares. The study employs the Rayleigh power as a test statistic to evaluate the evidence for periodic emissions. We find no evidence of periodic emissions from these events at these frequencies. In all but a very few cases the maximum power values obtained are consistent with what would be expected by chance from a non-periodic signal. In those few instances where there is marginal evidence for periodicity there are problems with the data that cast doubt on the reality of the signal. For classical GRBs, the largest Rayleigh power occurs in bursts whose TTE data appear to be corrupted. For SGRs, our largest Raylei...
Gu, Yu; Tran, Trinh; Murase, Sachiko; Borrell, Andrew; Kirkwood, Alfredo; Quinlan, Elizabeth M
2016-10-05
Maturation of excitatory drive onto fast-spiking interneurons (FS INs) in the visual cortex has been implicated in the control of the timing of the critical period for ocular dominance plasticity. However, the mechanisms that regulate the strength of these synapses over cortical development are not understood. Here we use a mouse model to show that neuregulin (NRG) and the receptor tyrosine kinase erbB4 regulate the timing of the critical period. NRG1 enhanced the strength of excitatory synapses onto FS INs, which inhibited ocular dominance plasticity during the critical period but rescued plasticity in transgenics with hypoexcitable FS INs. Blocking the effects of endogenous neuregulin via inhibition of erbBs rescued ocular dominance plasticity in postcritical period adults, allowing recovery from amblyopia induced by chronic monocular deprivation. Thus, the strength of excitation onto FS INs is a key determinant of critical period plasticity and is maintained at high levels by NRG-erbB4 signaling to constrain plasticity in adulthood.
Analysis of log-periodic power law singularity patterns in time series related to credit risk
Wosnitza, Jan Henrik; Sornette, Didier
2015-04-01
The log-periodic (super-exponential) power law singularity (LPPLS) has become a promising tool for predicting extreme behavior of self-organizing systems in natural sciences and finance. Some researchers have recently proposed to employ the LPPLS on credit risk markets. The review article at hand summarizes four papers in this field and shows how they are linked. After structuring the research questions, we collect the corresponding answers from the four articles. This eventually gives us an overall picture of the application of the LPPLS to credit risk data. Our literature review begins with grounding the view that credit default swap (CDS) spreads are hotbeds for LPPLS patterns and it ends up with drawing attention to the recently proposed alarm index for the prediction of institutional bank runs. By presenting a new field of application for the LPPLS, the reviewed strand of literature further substantiates the LPPLS hypothesis. Moreover, the results suggest that CDS spread trajectories belong to a different universality class than, for instance, stock prices.
Examining job tenure and lost-time claim rates in Ontario, Canada, over a 10-year period, 1999-2008.
Morassaei, Sara; Breslin, F Curtis; Shen, Min; Smith, Peter M
2013-03-01
We sought to examine the association between job tenure and lost-time claim rates over a 10-year period in Ontario, Canada. Data were obtained from workers' compensation records and labour force survey data from 1999 to 2008. Claim rates were calculated for gender, age, industry, occupation, year and job tenure group. A multivariate analysis and examination of effect modification were performed. Differences in injury event and source of injury were also examined by job tenure. Lost-time claim rates were significantly higher for workers with shorter job tenure, regardless of other factors. Claim rates for new workers differed by gender, age and industry, but remained relatively constant at an elevated rate over the observed time period. This study is the first to examine lost-time claim rates by job tenure over a time period during which overall claim rates generally declined. Claim rates did not show a convergence by job tenure. Findings highlight that new workers are still at elevated risk, and suggest the need for improved training, reducing exposures among new workers, promoting permanent employment, and monitoring work injury trends and risk factors.
Institute of Scientific and Technical Information of China (English)
Hongmei Zhang; Fawang Liu
2007-01-01
In this paper, the space-time Riesz fractional partial differential equations with periodic conditions are considered. The equations are obtained from the integral partial differential equation by replacing the time derivative with a Caputo fractional derivative and the space derivative with Riesz potential. The fundamental solutions of the space Riesz fractional partial differential equation (SRFPDE) and the space-time Riesz fractional partial differential equation (STRFPDE) are discussed, respectively. Using methods of Fourier series expansion and Laplace transform, we derive the explicit expressions of the fundamental solutions for the SRFPDE and the STRFPDE, respectively.
Periodization of the european union’s immigration policy: from the beginning to modern times
Directory of Open Access Journals (Sweden)
K. Y. Fogel
2017-04-01
The main conclusion of the article is that, on the one hand, immigration has become a relevant issue in all the EU countries. On the other hand, as a consequence of different timing of immigration, different socio-economic contexts and varying governmental migration and integration policies, different forms of migration, with different governmental policies of migration and integration, and with different types of migrants have evolved. Such different starting positions should be taken into account when studying the consequences of the immigration and the presence of migrants in society.
Directory of Open Access Journals (Sweden)
Fabiana Mesquita Carvalho
2016-06-01
Full Text Available The updating of prospective internal models is necessary to accurately predict future observations. Uncertainty-driven internal model updating has been studied using a variety of perceptual paradigms, and have revealed engagement of frontal and parietal areas. In a distinct literature, studies on temporal expectations have also characterized a time-perception network, which relies on temporal orienting of attention. However, the updating of prospective internal models is highly dependent on temporal attention, since temporal attention must be reoriented according to the current environmental demands. In this study we used fMRI to evaluate to what extend the continuous manipulation of temporal prediction would recruit update-related areas and the time-perception network areas. We developed an exogenous temporal task that combines rhythm cueing and time-to-contact principles to generate implicit temporal expectation. Two patterns of motion were created: periodic (simple harmonic oscillation and non-periodic (harmonic oscillation with variable acceleration. We found that non-periodic motion engaged the exogenous temporal orienting network, which includes the ventral premotor and inferior parietal cortices, and the cerebellum, as well as the presupplementary motor area, which has previously been implicated in internal model updating, and the motion-sensitive area MT+. Interestingly, we found a right-hemisphere preponderance suggesting the engagement of explicit timing mechanisms. We also show that the periodic motion condition, when compared to the non-periodic motion, activated a particular subset of the default-mode network (DMN midline areas, including the left dorsomedial prefrontal cortex, anterior cingulate cortex, and bilateral posterior cingulate cortex/precuneus. It suggests that the DMN plays a role in processing contextually expected information and supports recent evidence that the DMN may reflect the validation of prospective internal
Chaotic particle sedimentation in a rotating flow with time-periodic strength
Angilella, J R
2010-01-01
Particle sedimentation in the vicinity of a fixed horizontal vortex with time-dependent intensity can be chaotic, provided gravity is sufficient to displace the particle cloud while the vortex is off or weak. This "stretch, sediment and fold" mechanism is close to the so-called blinking vortex effect, which is responsible for chaotic transport of perfect tracers, except that in the present case the vortex motion is replaced by gravitational settling. In the present work this phenomenon is analyzed for heavy Stokes particles moving under the sole effect of gravity and of a linear drag. The vortex is taken to be a fixed isolated point vortex the intensity of which varies under the effect of either boundary conditions or volume force. When the unsteadiness of the vortex is weak and the free-fall velocity is of the order of the fluid velocity, and the particle response time is small, the particle motion equation can be written asymptotically as a perturbed hamiltonian system the phase portrait of which displays a...
Influence of cosmic radiation on aerosol and cloud formation over short time periods
DEFF Research Database (Denmark)
Bondo, Torsten
This thesis describes a study of Forbush decrease events. These are rapid decreases in the cosmic ray intensity in the Earth’s atmosphere, which are caused by a temporary increased magnetic shielding at Earth due to solar eruptions. The aim is to investigate how these transient ionization phenomena...... for cosmic rays. A list of the ionization change in the troposphere of the strongest Forbush decreases as compared to the ionization change over the solar cycle is calculated and indicates that only a few events induce ionization changes comparable to the solar cycle. Studies of recently available high...... gas concentration on aerosol and cloud optical properties over short time. The model is used to examine experimental efforts at DTU Space on the role of ions in nucleation, as well as it is used to investigate observational data on Forbush decreases in aerosols. The model confirms the existence...
Light Delivery Over Extended Time Periods Enhances the Effectiveness of Photodynamic Therapy
Seshadri, Mukund; Bellnier, David A.; Vaughan, Lurine A.; Spernyak, Joseph A.; Mazurchuk, Richard; Foster, Thomas H.; Henderson, Barbara W.
2009-01-01
Purpose The rate of energy delivery is a principal factor determining the biological consequences of photodynamic therapy (PDT). In contrast to conventional high irradiance treatments, recent preclinical and clinical studies have focused on low irradiance schemes. The objective of this study was to investigate the relationship between irradiance, photosensitizer dose and PDT dose with regard to treatment outcome and tumor oxygenation in a rat tumor model. Experimental Design Using the photosensitizer HPPH (2-[1-hexyloxyethyl]-2 devinyl pyropheophorbide), a wide range of PDT doses that included clinically relevant photosensitizer concentrations were evaluated. Magnetic resonance imaging (MRI) and oxygen tension measurements were performed along with the Evans blue exclusion assay to assess vascular response, oxygenation status and tumor necrosis. Results In contrast to high incident laser power (150 mW), low power regimens (7 mW) yielded effective tumor destruction. This was largely independent of PDT dose (drug-light product), with up to 30-fold differences in photosensitizer dose and 15-fold differences in drug-light product. For all drug-light products, the duration of light treatment positively influenced tumor response. Regimens utilizing treatment times of 120–240 mins showed marked reduction in signal intensity in T2-weighted MR images at both low (0.1 mg/kg) and high (3 mg/kg) drug doses compared to short duration (6–11 mins) regimens. Significantly greater reductions in pO2 were observed with extended exposures, which persisted after completion of treatment. Conclusions These results confirm the benefit of prolonged light exposure, identify vascular response as a major contributor and suggest that duration of light treatment (time) may be an important new treatment parameter. PMID:18451247
Morena, Matthew A; Franke, John E
2012-01-01
Periodic environments may either enhance or suppress a population via resonant or attenuant cycles. We derive signature functions for predicting the responses of two competing populations to 2-periodic oscillations in six model parameters. Two of these parameters provide a non-trivial equilibrium and two provide the carrying capacities of each species in the absence of the other, but the remaining two are arbitrary and could be intrinsic growth rates. Each signature function is the sign of a weighted sum of the relative strengths of the oscillations of the perturbed parameters. Periodic environments are favourable for populations when the signature function is positive and are deleterious if the signature function is negative. We compute the signature functions of four classical, discrete-time two-species populations and determine regions in parameter space which are either favourable or detrimental to the populations. The six-parameter models include the Logistic, Ricker, Beverton-Holt, and Hassell models.
Directory of Open Access Journals (Sweden)
Xiaokui Yue
2014-01-01
Full Text Available A numerical approach for obtaining periodic orbits of satellite relative motion is proposed, based on using the time domain collocation (TDC method to search for the periodic solutions of an exact J2 nonlinear relative model. The initial conditions for periodic relative orbits of the Clohessy-Wiltshire (C-W equations or Tschauner-Hempel (T-H equations can be refined with this approach to generate nearly bounded orbits. With these orbits, a method based on the least-squares principle is then proposed to generate projected closed orbit (PCO, which is a reference for the relative motion control. Numerical simulations reveal that the presented TDC searching scheme is effective and simple, and the projected closed orbit is very fuel saving.
Weng, Hengyi; Lau, K.-M.
1994-01-01
In this paper, preliminary results in using orthogonal and continuous wavelet transform (WT) to identify period doubling and time-frequency localization in both synthetic and real data are presented. First, the Haar WT is applied to synthetic time series derived from a simple nonlinear dynamical system- a first-order quadratic difference equation. Second, the complex Morlet WT is used to study the time-frequency localization of tropical convection based on a high-resolution Japanese Geostationary Meteorological Satellite infrared (IR) radiance dataset. The Haar WT of the synthetic time series indicates the presence and distinct separation of multiple frequencies in a period-doubling sequence. The period-doubling process generates a multiplicity of intermediate frequencies, which are manifested in the nonuniformity in time with respect to the phase of oscillations in the lower frequencies. Wavelet transform also enables the detection of extremely weak signals in high-order subharmonics resulting from the period-doubling bifurcations. These signals are either undetected or considered statistically insignificant by traditional Fourier analysis. The Morlet WT of the IR radiance dataset indicates the presence of multiple timescales, which are localized in both frequency and time. There are two regimes in the variation of IR radiance, corresponding to the wet and dry periods. Multiple timescales, ranging from semidiurnal, diurnal, synoptic, to intraseasonal with embedding structures, are active in the wet regime. In particular, synoptic variability is more prominent during the wet phase of an intensive intraseasonal cycle. These are not only consistent with, but also show more details than, previous findings by using other techniques. The phase-locking relationships among the oscillations with different time-scales suggest that both synoptic and intraseasonal variations may be mixed oscillations due to the interaction of self-excited oscillations in the tropical
Jiang, Tian-Yu; Li, Li-Fang; Han, Zhan-Wen; Jiang, Deng-Kai
2010-04-01
The first complete charge-coupled device (CCD) light curves in B and V passbands of a neglected contact binary system, CW Cassiopeiae (CW Cas), are presented. They were analyzed simultaneously by using the Wilson and Devinney (WD) code (1971, ApJ, 166, 605). The photometric solution indicates that CW Cas is a W-type W UMa system with a mass ratio of m2/m1 2.234, and that it is in a marginal contact state with a contact degree of ˜6.5% and a relatively large temperature difference of ˜327K between its two components. Based on the minimum times collected from the literature, together with the new ones obtained in this study, the orbital period changes of CW Cas were investigated in detail. It was found that a periodical variation overlaps with a secular period decrease in its orbital period. The long-term period decrease with a rate of dP/dt = -3.44 × 10-8d yr-1 can be interpreted either by mass transfer from the more-massive component to the less-massive with a rate of dm2/dt = -3.6 × 10-8M⊙ yr-1, or by mass and angular-momentum losses through magnetic braking due to a magnetic stellar wind. A low-amplitude cyclic variation with a period of T = 63.7 yr might be caused by the light-time effect due to the presence of a third body.
Energy Technology Data Exchange (ETDEWEB)
Kritzenberger, J.; Wokaun, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)
1997-06-01
Oxidation of CO over palladium/zirconia catalyst obtained from an amorphous Pd{sub 25}Zr{sub 75} precursor was investigated by time resolved FTIR spectroscopy. Sine wave shaped modulation of the reactant concentration, i.e. variation of CO or O{sub 2} partial pressure, was used to induce variations of the IR signals of product (CO{sub 2}) and unconverted reactant (CO), which were detected in a multi-pass absorption cell. The phase shift {phi} between external perturbation and variation of the CO{sub 2} signal was examined in dependence on temperature (100{sup o}C{<=}T{<=}350{sup o}C) and modulation frequency (1.39x10{sup -4}Hz{<=}{omega}{<=}6.67x10{sup -2}Hz). From the phase shift values, a simple Eley-Rideal mechanism is excluded, and the rate limiting step of the Langmuir-Hinshelwood mechanism for the CO oxidation may be identified. Adsorption and possible surface movement of CO to the actual reaction site determine the rate of the CO oxidation on the palladium/zirconia catalyst used in our study. The introduction of an external perturbation is a first step towards the application of two-dimensional infrared spectroscopy to heterogeneous catalyzed reactions. (author) 3 figs., 4 refs.
Maintaining high precision of isotope ratio analysis over extended periods of time.
Brand, Willi A
2009-06-01
Stable isotope ratios are reliable and long lasting process tracers. In order to compare data from different locations or different sampling times at a high level of precision, a measurement strategy must include reliable traceability to an international stable isotope scale via a reference material (RM). Since these international RMs are available in low quantities only, we have developed our own analysis schemes involving laboratory working RM. In addition, quality assurance RMs are used to control the long-term performance of the delta-value assignments. The analysis schemes allow the construction of quality assurance performance charts over years of operation. In this contribution, the performance of three typical techniques established in IsoLab at the MPI-BGC in Jena is discussed. The techniques are (1) isotope ratio mass spectrometry with an elemental analyser for delta(15)N and delta(13)C analysis of bulk (organic) material, (2) high precision delta(13)C and delta(18)O analysis of CO(2) in clean-air samples, and (3) stable isotope analysis of water samples using a high-temperature reaction with carbon. In addition, reference strategies on a laser ablation system for high spatial resolution delta(13)C analysis in tree rings is exemplified briefly.
Sontag, S J
1999-01-01
in children and adults is gradually weakened over time as a result of chronic straining to defecate and straining in an unphysiologic position, both of which stem from our modern day habits of eating a low-fiber diet and living on the high-seated toilet. We suggest that the chronic traumatic hiatal hernia is (a) the cause of more than 90 percent of the GERD that stalks the Western world; (b) is a direct result of abandoning the popular and worldwide practice of squatting to socialize, eat and defecate; and (c) is our just reward for adopting the "civilized" high sitting position on chairs and modern toilets.
Exploring What Determines the Use of Forecasts of Varying Time Periods in Guanacaste, Costa Rica
Babcock, M.; Wong-Parodi, G.; Grossmann, I.; Small, M. J.
2016-12-01
Weather and climate forecasts are promoted as ways to improve water management, especially in the face of changing environmental conditions. However, studies indicate many stakeholders who may benefit from such information do not use it. This study sought to better understand which personal factors (e.g., trust in forecast sources, perceptions of accuracy) were important determinants of the use of 4-day, 3-month, and 12-month rainfall forecasts by stakeholders in water management-related sectors in the seasonally dry province of Guanacaste, Costa Rica. From August to October 2015, we surveyed 87 stakeholders from a mix of government agencies, local water committees, large farms, tourist businesses, environmental NGO's, and the public. The result of an exploratory factor analysis suggests that trust in "informal" forecast sources (traditional methods, family advice) and in "formal" sources (government, university and private company science) are independent of each other. The result of logistic regression analyses suggest that 1) greater understanding of forecasts is associated with a greater probability of 4-day and 3-month forecast use, but not 12-month forecast use, 2) a greater probability of 3-month forecast use is associated with a lower level of trust in "informal" sources, and 3), feeling less secure about water resources, and regularly using many sources of information (and specifically formal meetings and reports) are each associated with a greater probability of using 12-month forecasts. While limited by the sample size, and affected by the factoring method and regression model assumptions, these results do appear to suggest that while forecasts of all times scales are used to some extent, local decision makers' decisions to use 4-day and 3-month forecasts appear to be more intrinsically motivated (based on their level of understanding and trust) and the use of 12-month forecasts seems to be more motivated by a sense of requirement or mandate.
Identifying Thermally Challenging Landscapes and Time Periods for Wildlife Using Remote Sensing
Albright, T. P.; Pidgeon, A.; Radeloff, V.; Wardlow, B.
2011-12-01
Recent events and climate model outputs indicate an increase in the occurrence and magnitude of heat waves and other high temperature events in many locations. Temperatures at the land surface may be much higher than air temperatures making this a particularly relevant consideration for animals that nest, forage, or seek refuge at or near the ground. Often associated with heat waves are prolonged and/or rapid onset drought events, which can combine to place stress on vegetation and animals. In order to assess the influence of heat waves and drought on communities of birds, we developed statistical models between avian abundance and species richness data collected by volunteer observers as part of the North American Breeding Bird Survey and a suite of precipitation and temperature metrics. We used station data, gridded standardized precipitation indices, and remotely sensed vegetation indices, and developed an index of accumulated temperature exceedance using time series MODIS land surface temperature (LST) products. Mixed effects models accounting for nuisance factors and temporal autocorrelation revealed that LST was among the strongest predictors of same year and following-year avian abundance. In particular, declines in abundance were largest and most common among ground-nesting birds and long-distance migrants in the US Southwest. In cooler regions, high LST exceedances were sometimes associated with increases in abundance. Because these results do not indicate whether dispersal, reproductive effort, or mortality explain the changes, one area of current research focuses on identifying demographic mechanisms and population consequences of such responses. A second area of active research focuses on using LST data in conjunction with digital elevation models and derivatives and dense networks of ground-level observations to produce physiologically-relevant indicators of thermally stressful conditions for birds and other animals.
Cai, Zuowei; Huang, Lihong; Guo, Zhenyuan; Chen, Xiaoyan
2012-09-01
This paper investigates the periodic dynamics of a general class of time-varying delayed neural networks with discontinuous right-hand sides. By employing the topological degree theory in set-valued analysis, differential inclusions theory and Lyapunov-like approach, we perform a thorough analysis of the existence, uniqueness and global exponential stability of the periodic solution for the neural networks. Especially, some sufficient conditions are derived to guarantee the existence, uniqueness and global exponential stability of the equilibrium point for the autonomous systems corresponding to the non-autonomous neural networks. Furthermore, the global convergence of the output and the convergence in finite time of the state are also discussed. Without assuming the boundedness or monotonicity of the discontinuous neuron activation functions, the obtained results improve and extend previous works on discontinuous or continuous neural network dynamical systems. Finally, two numerical examples are provided to show the applicability and effectiveness of our main results.
Rostworowski, Andrzej
2017-06-01
Motivated by the problem of stability of anti-de Sitter (AdS) spacetime, we discuss nonlinear gravitational perturbations of maximally symmetric solutions of vacuum Einstein equations in general and the case of AdS in particular. We present the evidence that, similarly to the self-gravitating scalar field at spherical symmetry, the negative cosmological constant allows for the existence of globally regular asymptotically AdS, time-periodic solutions of vacuum Einstein equations whose frequencies bifurcate from linear eigenfrequencies of AdS. Interestingly, our preliminary results indicate that the number of one-parameter families of time-periodic solutions bifurcating from a given eigenfrequency equals the multiplicity of this eigenfrequency.
Ferruzzo Correa, Diego P.; Bueno, Átila M.; Castilho Piqueira, José R.
2017-04-01
In this paper we investigate stability conditions for small-amplitude periodic solutions emerging near symmetry-preserving Hopf bifurcations in a time-delayed fully-connected N-node PLL network. The study of this type of systems which includes the time delay between connections has attracted much attention among researchers mainly because the delayed coupling between nodes emerges almost naturally in mathematical modeling in many areas of science such as neurobiology, population dynamics, physiology and engineering. In a previous work it has been shown that symmetry breaking and symmetry preserving Hopf bifurcations can emerge in the parameter space. We analyze the stability along branches of periodic solutions near fully-synchronized Hopf bifurcations in the fixed-point space, based on the reduction of the infinite-dimensional space onto a two-dimensional center manifold in normal form. Numerical results are also presented in order to confirm our analytical results.
Yan, Weixian
2017-01-01
The tunneling of the massless and massive Dirac particle through the strained barriers driven by the time-periodic scalar potentials and the static vector potentials is investigated, where the interrelationships among the strain, the incidence angle, the dynamic scalar potential, the magnetic field and the transmission of the Dirac particle have been discussed. In either massless or massive case, the intersection angle between the obliquely incident Dirac particle and strain determines the extent of deviation of the tunneling profiles from the strainless case. The time-periodic scalar potentials can enhance the capability of the Dirac particle to surmount the energy gap induced by the mass, reflecting quantum nature of the photon-assisted tunneling. When the magnetic field is switched on, the transmission overall presents a remarkably different profile, and decreases with the increase of the magnetic fields due to the conservation of the transverse momentum, which reduces the number of the side-band channels for tunneling.
Thaker, Nikhil G; Pugh, Thomas J; Mahmood, Usama; Choi, Seungtaek; Spinks, Tracy E; Martin, Neil E; Sio, Terence T; Kudchadker, Rajat J; Kaplan, Robert S; Kuban, Deborah A; Swanson, David A; Orio, Peter F; Zelefsky, Michael J; Cox, Brett W; Potters, Louis; Buchholz, Thomas A; Feeley, Thomas W; Frank, Steven J
2016-01-01
Value, defined as outcomes over costs, has been proposed as a measure to evaluate prostate cancer (PCa) treatments. We analyzed standardized outcomes and time-driven activity-based costing (TDABC) for prostate brachytherapy (PBT) to define a value framework. Patients with low-risk PCa treated with low-dose-rate PBT between 1998 and 2009 were included. Outcomes were recorded according to the International Consortium for Health Outcomes Measurement standard set, which includes acute toxicity, patient-reported outcomes, and recurrence and survival outcomes. Patient-level costs to 1 year after PBT were collected using TDABC. Process mapping and radar chart analyses were conducted to visualize this value framework. A total of 238 men were eligible for analysis. Median age was 64 (range, 46-81). Median followup was 5 years (0.5-12.1). There were no acute Grade 3-5 complications. Expanded Prostate Cancer Index Composite 50 scores were favorable, with no clinically significant changes from baseline to last followup at 48 months for urinary incontinence/bother, bowel bother, sexual function, and vitality. Ten-year outcomes were favorable, including biochemical failure-free survival of 84.1%, metastasis-free survival 99.6%, PCa-specific survival 100%, and overall survival 88.6%. TDABC analysis demonstrated low resource utilization for PBT, with 41% and 10% of costs occurring in the operating room and with the MRI scan, respectively. The radar chart allowed direct visualization of outcomes and costs. We successfully created a visual framework to define the value of PBT using the International Consortium for Health Outcomes Measurement standard set and TDABC costs. PBT is associated with excellent outcomes and low costs. Widespread adoption of this methodology will enable value comparisons across providers, institutions, and treatment modalities. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
Defining "intermittent UVR exposure"
DEFF Research Database (Denmark)
Bodekær, Mette; Philipsen, Peter Alshede; Petersen, Bibi Øager;
2016-01-01
to define and quantify “intermittent UVR exposure” by an objective measure. Methods: A broad study population of adults and children had data collected during a summer period. Data were personal UVR dosimetry measurements, from which the number of “intermittent days” was derived, sun behaviour diaries.......001). The corresponding numbers for prediction of nevi and lentigo density by retrospective questionnaire data was lower (R2 = 0.11, R2 = 0.26, p defined objective measure of intermittent UVR exposure. This measure may provide a better prediction of solar skin damage and CMM...
Duan, Lian; Huang, Lihong
2014-09-01
In this paper, we investigate a class of memristor-based neural networks with general mixed delays involving both time-varying delays and distributed delays. By using the Mawhin-like coincidence theorem, together with the differential inclusion theory, M-matrix properties and differential inequality techniques, some novel criteria are established for ensuring the periodicity and dissipativity for the addressed neural networks. Finally, two numerical examples with simulations are presented to demonstrate the effectiveness of the theoretical results.
Mazzocco, Michele M M; Devlin, Kathleen T; McKenney, Sarah J
2008-01-01
Poor fact retrieval is a frequently reported characteristic of children with mathematical learning disability (MLD). To better understand the nature and specificity of poor fact retrieval in MLD, in the present study, we examined eighth graders' accuracy on timed addition and multiplication problems of varying levels of difficulty. We compared the performance of 16 children with deficient math achievement (MLD), 19 children with below average (but not deficient) math achievement (LA), and 100 typically achieving (TA) children. Children in all three groups made errors. Errors made by children in the LA group were more numerous, but comparable in type, to those observed for typically developing children. Errors made by children with MLD were more numerous still, and included errors that differ qualitatively from those in the LA and TA groups. Thus the way in which performance linked to "math difficulties" differs from that of typically achieving children varies as a function of how we define math disabilities (MLD vs. LA). Moreover, the frequency and types of errors made by individuals varied within the MLD group, highlighting group heterogeneity even when using strict criteria to define this group of children. Finally, the types of errors made by children with MLD reflect reliance on processes other than retrieval to solve these alleged "math facts."
Ibrahim, Slim
2011-01-01
We investigate large time existence of solutions of the Navier-Stokes-Boussinesq equations with spatially almost periodic large data when the density stratification is sufficiently large. In 1996, Kimura and Herring \\cite{KH} examined numerical simulations to show a stabilizing effect due to the stratification. They observed scattered two-dimensional pancake-shaped vortex patches lying almost in the horizontal plane. Our result is a mathematical justification of the presence of such two-dimensional pancakes. To show the existence of solutions for large times, we use $\\ell^1$-norm of amplitudes. Existence for large times is then proven using techniques of fast singular oscillating limits and bootstrapping argument from a global-in-time unique solution of the system of limit equations.
Sinclair, Amber Hughes; Edgerton, Eric S; Wyzga, Ron; Tolsma, Dennis
2010-02-01
Concentrations of numerous ambient air pollutants have declined in recent years across the United States. Although it can be expected that reductions in air pollutants are associated with reductions in health effects, it is unclear whether this is actually the case. The purpose of this analysis was to compare the levels of and relationships between air pollutants and acute respiratory outpatient visits for two consecutive time periods totaling 53 mo. Air pollution data were collected at a centrally located monitor in Atlanta, GA, and include 24-hr averages of particulate matter (PM) less than 2.5 microm in aerodynamic diameter (PM2.5) and its components; coarse PM (PM10-2.5); PM less than 10 microm in aerodynamic diameter (PM10); oxygenated volatile organic compounds (OVOCs); 8-hr maximum ozone (O3); and 1-hr maximum nitrogen dioxide (NO2), carbon monoxide (CO), and sulfur dioxide (SO2). In addition, several metals and fractions of elemental carbon (EC) and organic carbon (OC) were investigated. Daily outpatient visit data were obtained from the electronic data warehouse of the Atlanta-based region of a nonprofit managed care organization. Poisson general linear modeling determined associations between daily levels of acute visits for four diagnosis groups (adult and child asthma, upper and lower respiratory infection) and air pollution measurements. Overall declining trends were observed in air pollutants and acute visits over the study period. Childhood asthma had the greatest number of significant associations with air pollutants, namely zinc and EC. The significant lag time between pollutant measurement and visit occurrence changed from 3-5 days in the first time period to 6-8 days in the later time period, but there was general consistency in several childhood asthma and pollutant associations over both time periods. The greatest evidence for a reduction in pollution being associated with an improvement in health response was for lower respiratory disease
Clegg, Isabella L K; Rödel, Heiko G; Cellier, Marjorie; Vink, Dennis; Michaud, Isaure; Mercera, Birgitta; Böye, Martin; Hausberger, Martine; Lemasson, Alban; Delfour, Fabienne
2017-08-01
Behavioral patterns are established in response to predictable environmental cues. Animals under human care frequently experience predictable, human-controlled events each day, but very few studies have questioned exactly how behavioral patterns are affected by such activities. Bottlenose dolphins (Tursiops truncatus) maintained for public display are good models to study such patterns since they experience multiple daily human-controlled periods (e.g., shows, training for shows, medical training). Thus, we investigated the effect of training session schedule on their "free-time" behavior, studying 29 individuals within 4 groups from 3 European facilities. Our initial time budget analyses revealed that among the behaviors studied, dolphins spent the most time engaged in synchronous swimming, and within this category swam most at slow speeds and in close proximity to each other. "Slow-close" synchronous swimming peaked shortly after training sessions and was low shortly before the next session. Play behavior had significantly higher frequencies in juveniles than in adults, but the effect was only seen during the in-between session period (interval neither shortly before nor after sessions). Anticipatory behavior toward sessions was significantly higher shortly before sessions and lower afterward. We conclude that dolphin behaviors unconnected to the human-controlled periods were modulated by them: slow-close synchronous swimming and age-dependent play, which have important social dimensions and links to welfare. We discuss potential parallels to human-controlled periods in other species, including humans themselves. Our findings could be taken into account when designing welfare assessments, and aid in the provision of enrichment and maintaining effective schedules beneficial to animals themselves. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Potgieter, M. S.; Le Roux, J. A.
1992-01-01
A time-dependent drift model is used to simulate the heliospheric modulation of galactic cosmic rays, with emphasis on the effects of the wavy heliospheric neutral sheet (HNS) as a function of time during the period 1985-1990. The model predicted a clearly defined time difference between the time when minimum modulation occurred at earth and at radial distances farther away from the sun, indicating that the HNS plays an important part in establishing this observed time delay. The movements of the Voyager 1 and 2 and Pioneer 10 spacecraft were simulated in order to calculate instantaneous radial and latitudinal gradients. The time dependencies of these gradients were found to follow the observations well. The model study indicates that the HNS cannot be ignored, especially during periods of low to moderate solar activity, when the modulation of cosmic rays is described.
26 CFR 1.1250-2 - Additional depreciation defined.
2010-04-01
... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Additional depreciation defined. 1.1250-2... Additional depreciation defined. (a) In general—(1) Definition for purposes of section 1250(b)(1). Except as... depreciation means: (i) In the case of property which at the time of disposition has a holding period...
Directory of Open Access Journals (Sweden)
Masahide Usami
Full Text Available BACKGROUND/AIM: The questionnaire-children with difficulties (QCD is a parent-assessed questionnaire designed to evaluate a child's difficulties in functioning during specific time periods of the day. In this study, the QCD was applied to determine the time periods of the day that are concerning for the parents of children with attention deficit hyperactivity disorder (ADHD. The results were compared with those for a community sample. METHODS: Elementary and junior high school students with ADHD (243 boys, 55 girls and a community sample of children (518 boys, 618 girls were enrolled in this study. Their behaviors were assessed by the QCD, the ADHD-rating scale (ADHD-RS, and the Oppositional Defiant Behavior Inventory (ODBI. The effects of gender (boy/girl and diagnosis (ADHD/community sample on the total QCD score were analyzed across each school grade (elementary/junior high school. Correlation coefficients between QCD and ADHD-RS/ODBI scores were analyzed. RESULTS: The QCD score for the ADHD group was significantly lower than that for the community sample (P 0.41, P 0.40, P < 0.001. CONCLUSIONS: Parents reported that children with ADHD faced greater difficulties in completing basic daily activities compared with the community controls, particularly in the evening. Furthermore, these difficulties were related to the severity of ADHD symptoms. The parents' perceptions depended on the gender, ADHD and oppositional symptoms, and the time period of the day. This study determined that children with ADHD face greater difficulties in daily functioning compared with community sample children, that these difficulties are time-dependent, and that these difficulties were particularly experienced in the evening.
Zheng, Y; Escabí, M A
2013-08-01
Temporal sound cues are essential for sound recognition, pitch, rhythm, and timbre perception, yet how auditory neurons encode such cues is subject of ongoing debate. Rate coding theories propose that temporal sound features are represented by rate tuned modulation filters. However, overwhelming evidence also suggests that precise spike timing is an essential attribute of the neural code. Here we demonstrate that single neurons in the auditory midbrain employ a proportional code in which spike-timing precision and firing reliability covary with the sound envelope cues to provide an efficient representation of the stimulus. Spike-timing precision varied systematically with the timescale and shape of the sound envelope and yet was largely independent of the sound modulation frequency, a prominent cue for pitch. In contrast, spike-count reliability was strongly affected by the modulation frequency. Spike-timing precision extends from sub-millisecond for brief transient sounds up to tens of milliseconds for sounds with slow-varying envelope. Information theoretic analysis further confirms that spike-timing precision depends strongly on the sound envelope shape, while firing reliability was strongly affected by the sound modulation frequency. Both the information efficiency and total information were limited by the firing reliability and spike-timing precision in a manner that reflected the sound structure. This result supports a temporal coding strategy in the auditory midbrain where proportional changes in spike-timing precision and firing reliability can efficiently signal shape and periodicity temporal cues.
Li, Hongfei; Jiang, Haijun; Hu, Cheng
2016-03-01
In this paper, we investigate a class of memristor-based BAM neural networks with time-varying delays. Under the framework of Filippov solutions, boundedness and ultimate boundedness of solutions of memristor-based BAM neural networks are guaranteed by Chain rule and inequalities technique. Moreover, a new method involving Yoshizawa-like theorem is favorably employed to acquire the existence of periodic solution. By applying the theory of set-valued maps and functional differential inclusions, an available Lyapunov functional and some new testable algebraic criteria are derived for ensuring the uniqueness and global exponential stability of periodic solution of memristor-based BAM neural networks. The obtained results expand and complement some previous work on memristor-based BAM neural networks. Finally, a numerical example is provided to show the applicability and effectiveness of our theoretical results.
Twin peak quasi-periodic oscillations and the kinematics of orbital motion in a curved space-time
Germanà, Claudio
2012-01-01
Twin peak high frequency quasi-periodic oscillations (HF QPOs) observed in the power spectra of Low Mass X-ray Binaries (LMXBs), with either a black hole or a neutron star, have central frequencies that are typical of the orbital motion time-scale close to the compact object. Thus, twin HF QPOs might carry the fingerprint of physical effects in a strongly curved space-time. We study the azimuth phase \\phi(t) for orbital motion in the Schwarzschild metric and calculate the power spectra to check whether they display the features seen in the observed ones. We show that the timing of \\phi(t) on non-closed orbits can account for the observed twin peak HF QPOs. The uppermost couple of peaks in frequency has the lower peak that corresponds to the azimuthal frequency \
Crum, Matthew F; Trevaskis, Natalie L; Pouton, Colin W; Porter, Christopher J H
2017-02-06
The current studies sought to explore the impact of drug supersaturation and precipitation during the dispersion and digestion of lipid-based formulations (LBFs), on in vivo absorption using a coupled in vitro digestion-in vivo perfusion absorption model. Fenofibrate absorption was evaluated from a number of LBFs with different solubilization and supersaturation capacities, and conditions at the absorptive membrane manipulated by changing perfusion conditions, intestine segment lengths, and by the conduct of experiments in the presence or absence of suspended/precipitated drug. LBF dispersion and digestion resulted in varying periods of supersaturation across the different formulations. Even fleeting (5-10 min) periods of supersaturation were able to drive flux across a perfused 10 cm intestinal segment for up to 60 min, although over longer infusion periods (60-80 min) flux dropped in the absence of ongoing drug solubilization and supersaturation. In contrast, the presence or absence of precipitated/suspended drug, had little impact on drug flux. When perfused intestinal segment lengths were extended, the role of initial supersaturation was attenuated and ongoing solubilization conditions became the primary driver of absorptive flux. The data suggest that for highly permeable drugs such as fenofibrate, a short period of supersaturation at the absorptive membrane may be sufficient to drive absorptive drug flux in spite of significant drug precipitation on formulation dispersion or digestion in vitro. In contrast, where longer periods of absorption are required, for example, at higher doses, the requirement for ongoing solubilization and supersaturation becomes more apparent.
Maruddani, Di Asih I.; Rosadi, Dedi; Gunardic, Abdurakhman
2015-02-01
The value of a corporate bond is conventionally expressed in terms of zero coupon bond. In practice, the most common form of debt instrument is coupon bond and allows early default before maturity as safety covenant for the bondholder. This paper study valuation for one period coupon bond, a coupon bond that only give one time coupon at the bond period. It assumes that the model give bondholder the right to reorganize a firm if its value falls below a given barrier. Revised first passage time approach is applied for default time rule. As a result, formulas of equity, liability, and probability of default is derived for this specified model. Straightforward integration under risk neutral pricing is used for deriving those formulas. For the application, bond of Bank Rakyat Indonesia (BRI) as one of the largest bank in Indonesia is analyzed. R computing show that value of the equity is IDR 453.724.549.000.000, the liability is IDR 2.657.394.000.000, and the probability if default is 5.645305E-47 %.
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Hala A. Fergany
2005-01-01
Full Text Available This study treats the probabilistic safety stock n-items inventory system having varying order cost and zero lead-time subject to two linear constraints. The expected total cost is composed of three components: the average purchase cost; the expected order cost and the expected holding cost. The policy variables in this model are the number of periods Nr* and the optimal maximum inventory level Qmr* and the minimum expected total cost. We can obtain the optimal values of these policy variables by using the geometric programming approach. A special case is deduced and an illustrative numerical example is added.
DEFF Research Database (Denmark)
Nguyen, Trieu; van der Meer, Devaraj; van den Berg, Albert
2017-01-01
-Boltzmann equation, together with the incompressible Cauchy momentum equation under no-slip boundary conditions for viscoelastic fluid in the case of a combination of time periodic pressure-driven and electro-osmotic flow. The resulting solutions allow us to predict the electrical current and solution flow rate....... As expected from the assumption of linear viscoelasticity, the results satisfy the Onsager reciprocal relation, which is important since it enables an analogy between fluidic networks in this flow configuration and electric circuits. The results especially are of interest for micro-and nanofluidic energy...
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D. Carpentier
2015-07-01
Full Text Available We present mathematical details of the construction of a topological invariant for periodically driven two-dimensional lattice systems with time-reversal symmetry and quasienergy gaps, which was proposed recently by some of us. The invariant is represented by a gap-dependent Z2-valued index that is simply related to the Kane–Mele invariants of quasienergy bands but contains an extra information. As a byproduct, we prove new expressions for the two-dimensional Kane–Mele invariant relating the latter to Wess–Zumino amplitudes and the boundary gauge anomaly.
Hoffmann, Dirk L.; Rogerson, Mike; Spötl, Christoph; Luetscher, Marc; Vance, Derek; Osborne, Anne H.; Fello, Nuri M.; Moseley, Gina E.
2016-11-01
We present the first speleothem-derived central North Africa rainfall record for the last glacial period. The record reveals three main wet periods at 65-61 ka, 52.5-50.5 ka and 37.5-33 ka that lead obliquity maxima and precession minima. We find additional minor wet episodes that are synchronous with Greenland interstadials. Our results demonstrate that sub-tropical hydrology is forced by both orbital cyclicity and North Atlantic moisture sources. The record shows that after the end of a Saharan wet phase around 70 ka ago, North Africa continued to intermittently receive substantially more rainfall than today, resulting in favourable environmental conditions for modern human expansion. The encounter and subsequent mixture of Neanderthals and modern humans - which, on genetic evidence, is considered to have occurred between 60 and 50 ka - occurred synchronously with the wet phase between 52.5 and 50.5 ka. Based on genetic evidence the dispersal of modern humans into Eurasia started less than 55 ka ago. This may have been initiated by dry conditions that prevailed in North Africa after 50.5 ka. The timing of a migration reversal of modern humans from Eurasia into North Africa is suggested to be coincident with the wet period between 37.5 and 33 ka.
Komrska, Shelley; Rupe, Melissa
2005-01-01
Last year, a school embarked on a school-wide project that would take all of their students, kindergarten through-sixth grade, through a tangible art timeline. The result was a passageway--over seventy-five feet in length--that revealed the history of art, from cave painting to modern-day graffiti art. The "walk through time" was inspired by how…
Ferri, Raffaele; Manconi, Mauro; Plazzi, Giuseppe; Bruni, Oliviero; Cosentino, Filomena I I; Ferini-Strambi, Luigi; Zucconi, Marco
2012-05-01
Approximately one third of patients with restless legs syndrome (RLS) also show periodic leg movements (PLM) during relaxed wake fulness (PLMW). In contrast with the large amount of data published on periodic leg movements during sleep (PLMS), PLMW have received less attention from the scientific community. The objective of this study was to evaluate the correlations/differences of time-structure and response to a dopamine-agonist between PLMW and PLMS in patients with RLS. Ninety idiopathic RLS patients and 28 controls were recruited. Subjects underwent clinical and neurophysiological evaluation, hematological screening, and one or two consecutive full-night polysomnographic studies. A subset of patients received 0.25mg of pramipexole or placebo before the second recording. Polysomnographic recordings were scored and LM activity was analyzed during sleep and during the epochs of wakefulness occurring during the first recording hour. RLS patients had higher LM activity during wakefulness than controls, but with a similar periodicity. Even if correlated, the ability of the PLMW index to predict the PLMS index decreased with increasing LM activity. Intermovement intervals during wakefulness showed one peak only at approximately 4s, gradually decreasing with increasing interval in both patients and controls. The effect of pramipexole was very limited and involved the small periodic portion of LM activity during wakefulness. PLMW index and PLMS index were correlated; however, the magnitude of this correlation was not sufficient to suggest that PLMW can be good predictors of PLMS. Short-interval LM activity during wakefulness and sleep might be linked to the severity of sleep disruption in RLS patients and the differences between their features obtained during wakefulness or sleep might be relevant for the diagnosis of sleep disturbances in RLS. Copyright © 2012 Elsevier B.V. All rights reserved.
The nighttime F-region climatology during magnetically quiet periods seen from TIMED/GUVI and DMSP
Kil, H.; Paxton, L.; Zhang, Y.; Wolven, B.; Morrison, D.
2004-12-01
In this study, we investigate the drivers of the nighttime climatology in the low- and middle-latitude ionosphere during quiet periods using the TIMED/GUVI and DMSP data. The observation results show that the seasonal hemispheric asymmetry in plasma density is primary induced by the summer-to-winter wind circulations while the longitudinal variations of the F-region morphology is produced by the contribution of the zonal winds that depends on the magnetic declination. However, the F-region morphology observed at 625 km from TIMED/GUVI does not precisely conform the morphology observed at 840 km from DMSP. We will discuss the differential neutral wind effect on the F-region morphology depending on the magnetic declination, altitude, and the location of the geomagnetic equator relative to the geographic equator.
Roach, Gregory D; Sargent, Charli; Darwent, David; Dawson, Drew
2012-03-01
Most of the research related to human fatigue in the aviation industry has focussed on long-haul pilots, but short-haul pilots also experience elevated levels of fatigue. The aim of this study was to examine the impact of early start times on the amount of sleep obtained prior to duty and on fatigue levels at the start of duty. Seventy short-haul pilots collected data regarding their duty schedule and sleep/wake behaviour for at least two weeks. Data were collected using self-report duty/sleep diaries and wrist activity monitors. Mixed-effects regression analyses were used to examine the effects of duty start time (04:00-10:00 h) on (i) the total amount of sleep obtained in the 12h prior to the start of duty and (ii) self-rated fatigue level at the start of duty. Both analyses indicated significant main effects of duty start time. In particular, the amount of sleep obtained in the 12h prior to duty was lowest for duty periods that commenced between 04:00 and 05:00 h (i.e. 5.4h), and greatest for duty periods that commenced between 09:00 and 10:00 h (i.e. 6.6h). These data indicate that approximately 15 min of sleep is lost for every hour that the start of duty is advanced prior to 09:00 h. In addition, self-rated fatigue at the start of duty was highest for duty periods that commenced between 04:00 and 05:00 h, and lowest for duty periods that commenced between 09:00 and 10:00 h. Airlines should implement a fatigue risk management system (FRMS) for short-haul pilots required to work early-morning shifts. One component of the FRMS should be focussed on the production of 'fatigue-friendly' rosters. A second component of the FRMS should be focussed on training pilots to optimise sleep opportunities, to identify circumstances where the likelihood of fatigue is elevated, and to manage the risks associated with fatigue-related impairment.
Nam, Kwangho
2014-10-14
Development of multiscale ab initio quantum mechanical and molecular mechanical (AI-QM/MM) method for periodic boundary molecular dynamics (MD) simulations and their acceleration by multiple time step approach are described. The developed method achieves accuracy and efficiency by integrating the AI-QM/MM level of theory and the previously developed semiempirical (SE) QM/MM-Ewald sum method [J. Chem. Theory Comput. 2005, 1, 2] extended to the smooth particle-mesh Ewald (PME) summation method. In the developed methods, the total energy of the simulated system is evaluated at the SE-QM/MM-PME level of theory to include long-range QM/MM electrostatic interactions, which is then corrected on the fly using the AI-QM/MM level of theory within the real space cutoff. The resulting energy expression enables decomposition of total forces applied to each atom into forces determined at the low-level SE-QM/MM method and correction forces at the AI-QM/MM level, to integrate the system using the reversible reference system propagator algorithm. The resulting method achieves a substantial speed-up of the entire calculation by minimizing the number of time-consuming energy and gradient evaluations at the AI-QM/MM level. Test calculations show that the developed multiple time step AI-QM/MM method yields MD trajectories and potential of mean force profiles comparable to single time step QM/MM results. The developed method, together with message passing interface (MPI) parallelization, accelerates the present AI-QM/MM MD simulations about 30-fold relative to the speed of single-core AI-QM/MM simulations for the molecular systems tested in the present work, making the method less than one order slower than the SE-QM/MM methods under periodic boundary conditions.
Twenge, Jean M; Carter, Nathan T; Campbell, W Keith
2017-05-01
Orth, Trzesniewski, and Robins (2010) concluded that the nationally representative Americans' Changing Lives (ACL) cohort-sequential study demonstrated moderate to large age differences in self-esteem, and no birth cohort (generational) differences in the age trajectory. In a reanalysis of these data using 2 different statistical techniques, we find significant increases in self-esteem that could be attributed to birth cohort or time period. First, hierarchical linear modeling analyses with birth cohort as a continuous variable (vs. the multiple group formulation used by Orth et al.) find that birth cohort has a measurable influence on self-esteem through its interaction with age. Participants born in later years (e.g., 1960) were higher in self-esteem and were more likely to increase in self-esteem as they aged than participants born in earlier years (e.g., 1920). However, the estimated age trajectory up to age 60 is similar in Orth et al.'s results and in the results from our analyses including cohort. Second, comparing ACL respondents of the same age in 1986 versus 2002 (a time-lag design) yields significant birth cohort differences in self-esteem, with 2002 participants of the same age higher in self-esteem than those in 1986. Combined with some previous studies finding significant increases in self-esteem and positive self-views over time, these results suggest that cultural change in the form of cohort and time period cannot be ignored as influences in cross-sectional and longitudinal studies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
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Marușa Beca
2015-06-01
Full Text Available In this article, we studied the relationship between macroeconomic factors and the observed corporate births for the Romanian economy through the Autoregressive Distributed Lags Model (ADL. We performed a time series analysis that uses monthly data for the period January 2008 – December 2013 in order to establish the impact of the fiscal and monetary policy adopted by the Romanian government in times of economic crisis on the firms’ demography. The corporate birth rate is an endogenous variable in a linear function model with five exogenous macroeconomic variables such as the CPI, the loans ratio to GDP, the FDI, the long term interest rate, tax rate to GDP and the lags of the dependent variable. The main finding is that the variance of the corporate birth rate variable is negatively correlated with the variances of CPI in the current month and the interest rate two months lagged. We also determined that the variance of the dependent variable was positively correlated with the variances of the loans rate two months lagged, tax rate four months ago and FDI two months lagged and FDI in the current period.
Parra, M. A.; Santiago, J. L.; Martín, F.; Martilli, A.; Santamaría, J. M.
2010-06-01
The representativeness of point measurements in urban areas is limited due to the strong heterogeneity of the atmospheric flows in cities. To get information on air quality in the gaps between measurement points, and have a 3D field of pollutant concentration, Computational Fluid Dynamic (CFD) models can be used. However, unsteady simulations during time periods of the order of months, often required for regulatory purposes, are not possible for computational reasons. The main objective of this study is to develop a methodology to evaluate the air quality in a real urban area during large time periods by means of steady CFD simulations. One steady simulation for each inlet wind direction was performed and factors like the number of cars inside each street, the length of streets and the wind speed and direction were taken into account to compute the pollutant concentration. This approach is only valid in winter time when the pollutant concentrations are less affected by atmospheric chemistry. A model based on the steady-state Reynolds-Averaged Navier-Stokes equations (RANS) and standard k-ɛ turbulence model was used to simulate a set of 16 different inlet wind directions over a real urban area (downtown Pamplona, Spain). The temporal series of NO x and PM 10 and the spatial differences in pollutant concentration of NO 2 and BTEX obtained were in agreement with experimental data. Inside urban canopy, an important influence of urban boundary layer dynamics on the pollutant concentration patterns was observed. Large concentration differences between different zones of the same square were found. This showed that concentration levels measured by an automatic monitoring station depend on its location in the street or square, and a modelling methodology like this is useful to complement the experimental information. On the other hand, this methodology can also be applied to evaluate abatement strategies by redistributing traffic emissions.
Troyer, Jon; Peille, Philippe; Cackett, Edward; Barret, Didier
2017-08-01
Kilohertz quasi-periodic oscillations or kHz QPOs are intensity variations that occur in the X-ray band observed in neutron star low-mass X-ray binary (LMXB) systems. In such systems, matter is transferred from a secondary low-mass star to a neutron star via the process of accretion. kHz QPOs occur on the timescale of the inner accretion flow and may carry signatures of the physics of strong gravity (c2 ~ GM/R) and possibly clues to constraining the neutron star equation of state (EOS). Both the timing behavior of kHz QPOs and the time-averaged spectra of these systems have been studied extensively. No model derived from these techniques has been able to illuminate the origin of kHz QPOs. Spectral-timing is an analysis technique that can be used to derive information about the nature of physical processes occurring within the accretion flow on the timescale of the kHz QPO. To date, kHz QPOs of (4) neutron star LMXB systems have been studied with spectral-timing techniques. We present a comprehensive study of spectral-timing products of kHz QPOs from systems where data is available in the RXTE archive to demonstrate the promise of this technique to gain insights regarding the origin of kHz QPOs. Specifically, we show correlated time-lags as a function of QPO frequency and energy for the various LMXB systems where kHz QPOs are detected.
Balayla, Jacques; Wo, Bi Lan; Bédard, Marie-Josée
2015-01-01
Though no official guidelines address the issue of the optimal timing of delivery in placenta previa, common practice is to conduct delivery between 36 and 37 weeks gestation. Given the rising concerns regarding unnecessary premature deliveries, the objective of this study was to compare neonatal outcomes among pregnancies complicated by placenta previa delivered at the late-preterm period (35, 36 weeks) relative to the early-term period (37 and 38 weeks). We conducted a retrospective, population-based, cohort study using the CDC’s Linked Birth-Infant Death data files from the U.S. for the year 2004. We stratified the cohort according to gestational age and placenta previa status. Using 38 weeks gestation as reference controls, the effect of delivery in a pregnancy with placenta previa at 35, 36 and 37 weeks gestation on the risk of several neonatal outcomes was estimated using logistic regression analysis, adjusting for relevant confounders. We analyzed a total of 4 118 956 births, of which 5675 (0.1%) met inclusion criteria. Late-preterm delivery was associated with lower birthweight and increased adequacy of care. Relative to neonates born at 38 weeks, birth at 35, 36 and 37 weeks was associated with no greater odds of meconium passage, fetal distress, fetal anemia, neonatal seizures, increased ventilator needs, or infant death at 1 year. However, odds of 5-min APGAR scores placenta previa is associated with fewer complications and no greater risk than late-preterm delivery. This information may be helpful in the development of future guidelines, which are currently needed to guide the management of these pregnancies.
Fujiwara, A.; Hirawake, T.; Suzuki, K.; Eisner, L.; Imai, I.; Nishino, S.; Kikuchi, T.; Saitoh, S.-I.
2016-01-01
The size structure and biomass of a phytoplankton community during the spring bloom period can affect the energy use of higher-trophic-level organisms through the predator-prey body size relationships. The timing of the sea ice retreat (TSR) also plays a crucial role in the seasonally ice-covered marine ecosystem, because it is tightly coupled with the timing of the spring bloom. Thus, it is important to monitor the temporal and spatial distributions of a phytoplankton community size structure. Prior to this study, an ocean colour algorithm was developed to derive phytoplankton size index FL, which is defined as the ratio of chlorophyll a (chl a) derived from cells larger than 5 µm to the total chl a, using satellite remote sensing for the Chukchi and Bering shelves. Using this method, we analysed the pixel-by-pixel relationships between FL during the marginal ice zone (MIZ) bloom period and TSR over the period of 1998-2013. The influences of the TSR on the sea surface temperature (SST) and changes in ocean heat content (ΔOHC) during the MIZ bloom period were also investigated. A significant negative relationship between FL and the TSR was widely found in the shelf region during the MIZ bloom season. However, we found a significant positive (negative) relationship between the SST (ΔOHC) and TSR. Specifically, an earlier sea ice retreat was associated with the dominance of larger phytoplankton during a colder and weakly stratified MIZ bloom season, suggesting that the duration of the nitrate supply, which is important for the growth of large-sized phytoplankton in this region (i.e. diatoms), can change according to the TSR. In addition, under-ice phytoplankton blooms are likely to occur in years with late ice retreat, because sufficient light for phytoplankton growth can pass through the ice and penetrate into the water columns as a result of an increase in solar radiation toward the summer solstice. Moreover, we found that both the length of the ice-free season
Canizares, Mayilee; Hogg-Johnson, Sheilah; Gignac, Monique A M; Glazier, Richard H; Badley, Elizabeth M
2017-01-01
The use of complementary and alternative medicine (CAM) is growing. However the factors contributing to changes over time and to birth cohort differences in CAM use are not well understood. We used data from 10186 participants, who were aged 20-69 years at the first cycle of data collection in the longitudinal component of the Canadian National Population Health Survey (1994/95-2010/11). We examined chiropractic and other practitioner-based CAM use with a focus on five birth cohorts: pre-World War II (born 1925-1934); World War II (born 1935-1944); older baby boomers (born 1945-1954); younger baby boomers (born 1955-1964); and Gen Xers (born 1965-1974). The survey collected data every two years on predisposing (e.g., sex, education), enabling (e.g., income), behavior-related factors (e.g., obesity), need (e.g., chronic conditions), and use of conventional care (primary care and specialists). The findings suggest that, at corresponding ages, more recent cohorts reported greater CAM (OR = 25.9, 95% CI: 20.0; 33.6 for Gen Xers vs. pre-World War) and chiropractic use than their predecessors (OR = 2.2, 95% CI: 1.7; 2.8 for Gen Xers vs. pre-World War). There was also a secular trend of increasing CAM use, but not chiropractic use, over time (period effect) across all ages. Factors associated with cohort differences were different for CAM and chiropractic use. Cohort differences in CAM use were partially related to a period effect of increasing CAM use over time across all ages while cohort differences in chiropractic use were related to the higher prevalence of chronic conditions among recent cohorts. The use of conventional care was positively related to greater CAM use (OR = 1.8, 95% CI: 1.6; 2.0) and chiropractic use (OR = 1.2, 95% CI: 1.1; 1.4) but did not contribute to changes over time or to cohort differences in CAM and chiropractic use. The higher CAM use over time and in recent cohorts could reflect how recent generations are approaching their healthcare needs
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Adalberto Campo Arias
2013-09-01
Full Text Available Background. The term ‘homophobia’ was introduced in the academic context more than 40 years ago. However, its meaning has changed over time. Objective. To review the nouns used in the last twelve years to define homophobia. Methodology. The authors conducted a systematic search in Medline through Pubmed that included editorials, letters to editors, comments and narrative reviews, in English and Spanish. A qualitative analysis (Grounded theory was applied to analyze nouns used to define homophobia since 2001 through 2012. Results. Authors reviewed three papers including ten nouns to define homophobia, the most common noun was fear. The terms were grouped into two domains: negative attitude and discomfort with homosexuality. Conclusion. Fear is the most used word to describe homophobia. The terms were grouped into two domains: negative attitude and discomfort toward homosexuality.
Lee, Choon-Ki; Han, Shin-Chan; Dieter,Bilitza; Ki-Weon,Seo
2012-01-01
The 27-day variations of topside ionosphere are investigated using the in-situ electron density measurements from the CHAMP planar Langmuir probe and GRACE K-band ranging system. As the two satellite systems orbit at the altitudes of approx. 370 km and approx. 480 km, respectively, the satellite data sets are greatly valuable for examining the electron density variations in the vicinity of F2-peak. In a 27-day period, the electron density measurements from the satellites are in good agreements with the solar flux, except during the solar minimum period. The time delays are mostly 1-2 day and represent the hemispherical asymmetry. The globally-estimated spatial patterns of the correlation between solar flux and in-situ satellite measurements show poor correlations in the (magnetic) equatorial region, which are not found from the ground measurements of vertically-integrated electron content. We suggest that the most plausible cause for the poor correlation is the vertical movement of ionization due to atmospheric dynamic processes that is not controlled by the solar extreme ultraviolet radiation.
Fisher, Aaron J; Reeves, Jonathan W; Chi, Cyrus
2016-07-01
Expanding on recently published methods, the current study presents an approach to estimating the dynamic, regulatory effect of the parasympathetic nervous system on heart period on a moment-to-moment basis. We estimated second-to-second variation in respiratory sinus arrhythmia (RSA) in order to estimate the contemporaneous and time-lagged relationships among RSA, interbeat interval (IBI), and respiration rate via vector autoregression. Moreover, we modeled these relationships at lags of 1 s to 10 s, in order to evaluate the optimal latency for estimating dynamic RSA effects. The IBI (t) on RSA (t-n) regression parameter was extracted from individual models as an operationalization of the regulatory effect of RSA on IBI-referred to as dynamic RSA (dRSA). Dynamic RSA positively correlated with standard averages of heart rate and negatively correlated with standard averages of RSA. We propose that dRSA reflects the active downregulation of heart period by the parasympathetic nervous system and thus represents a novel metric that provides incremental validity in the measurement of autonomic cardiac control-specifically, a method by which parasympathetic regulatory effects can be measured in process.
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Ambrose, David M.; Wilkening, Jon
2008-12-11
We classify all bifurcations from traveling waves to non-trivial time-periodic solutions of the Benjamin-Ono equation that are predicted by linearization. We use a spectrally accurate numerical continuation method to study several paths of non-trivial solutions beyond the realm of linear theory. These paths are found to either re-connect with a different traveling wave or to blow up. In the latter case, as the bifurcation parameter approaches a critical value, the amplitude of the initial condition grows without bound and the period approaches zero. We propose a conjecture that gives the mapping from one bifurcation to its counterpart on the other side of the path of non-trivial solutions. By experimentation with data fitting, we identify the form of the exact solutions on the path connecting two traveling waves, which represents the Fourier coefficients of the solution as power sums of a finite number of particle positions whose elementary symmetric functions execute simple orbits in the complex plane (circles or epicycles). We then solve a system of algebraic equations to express the unknown constants in the new representation in terms of the mean, a spatial phase, a temporal phase, four integers (enumerating the bifurcation at each end of the path) and one additional bifurcation parameter. We also find examples of interior bifurcations from these paths of already non-trivial solutions, but we do not attempt to analyze their algebraic structure.
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Vesna Vučinić-Nešković
2016-02-01
Full Text Available This paper deals with the question of how the state policies during the later Maoist period, from the beginning of the Great Leap Forward (1958 to the introduction of the Modernization Reforms (1978, affected the organization of time in the Chinese countryside. After abandoning the initial Soviet model of modernization, based on the exclusive strengthening of heavy industry, the China’s leadership developed a strategy of parallel development of agriculture and industry, wherein the former would additionally support the modernization of the latter. The study is focused on the ways the longer term state plans and shorter term economic, social and ideological policies and campaigns jointly influenced the rhythms of life of Chinese peasants. The domains in which these influences became visible were: (1 the intensification of agricultural practices, (2 the introducing of the small-scale industry, and (3 the politicizing of the spare time. In the analysis the characteristic rhythms of work and rest within the daily, weekly, seasonal, and annual time spans are followed in detail.
Time delays in quasi-periodic pulsations observed during the X2.2 solar flare on 2011 February 15
Dolla, L; Seaton, D B; Van Doorsselaere, T; Dominique, M; Berghmans, D; Cabanas, C; De Groof, A; Schmutz, W; Verdini, A; West, M J; Zender, J; Zhukov, A N
2012-01-01
We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on time scale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) channels in the range 25-100 keV lead all the other channels. They are followed by the Nobeyama RadioPolarimeters at 9 and 17 GHz and the Extreme Ultra-Violet (EUV) channels of the Euv SpectroPhotometer (ESP) onboard the Solar Dynamic Observatory (SDO). The Zirconium and Aluminum filter channels of the Large Yield Radiometer (LYRA) onboard the Project for On-Board Autonomy (PROBA2) satellite and the SXR channel of ESP follow. The largest lags occur in observations from the Geostationary Operational Environmental Satellite (GOES), where the channel at 1-8 {\\AA} leads the 0.5-4 {\\AA} channel by several seconds. The time lags between the first and last channels is up to 9 ...
TIME DELAYS IN QUASI-PERIODIC PULSATIONS OBSERVED DURING THE X2.2 SOLAR FLARE ON 2011 FEBRUARY 15
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Dolla, L.; Marque, C.; Seaton, D. B.; Dominique, M.; Berghmans, D.; Cabanas, C.; De Groof, A.; Verdini, A.; West, M. J.; Zhukov, A. N. [Solar-Terrestrial Center of Excellence, Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Brussels (Belgium); Van Doorsselaere, T. [Centrum voor Plasma-Astrofysica, Department of Mathematics, KULeuven, Celestijnenlaan 200B bus 2400, B-3001 Leuven (Belgium); Schmutz, W. [Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf (Switzerland); Zender, J., E-mail: dolla@sidc.be [European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands)
2012-04-10
We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on timescale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager channels in the range 25-100 keV lead all the other channels. They are followed by the Nobeyama RadioPolarimeters at 9 and 17 GHz and the extreme-ultraviolet (EUV) channels of the Euv SpectroPhotometer (ESP) on board the Solar Dynamic Observatory. The zirconium and aluminum filter channels of the Large Yield Radiometer on board the Project for On-Board Autonomy satellite and the soft X-ray (SXR) channel of ESP follow. The largest lags occur in observations from the Geostationary Operational Environmental Satellite, where the channel at 1-8 A leads the 0.5-4 A channel by several seconds. The time lags between the first and last channels is up to Almost-Equal-To 9 s. We identified at least two distinct time intervals during the flare impulsive phase, during which the QPPs were associated with two different sources in the Nobeyama RadioHeliograph at 17 GHz. The radio as well as the hard X-ray channels showed different lags during these two intervals. To our knowledge, this is the first time that time lags are reported between EUV and SXR fluctuations on these timescales. We discuss possible emission mechanisms and interpretations, including flare electron trapping.
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Amit kumar Mishra
2015-01-01
Full Text Available In this paper, we have analyzed the effect of time periodic temperature modulation on convective stability in anisotropic porous cavity. The cavity is heated from below and cooled from above. A weakly non-linear stability analysis is done to find Nusselt number governing the heat transport. The infinitely small disturbances are expanded in terms of power series of amplitude of modulation. Analytically the nonautonomous Ginzburg- landau amplitude equation is obtained for the stationary mode of convection. The effects of various parameters like Vadasz number, mechanical and thermal anisotropic parameters, amplitude of oscillations, frequency of modulation and aspect ratio of the cavity on heat transport is studied and plotted graphically. It is observed that the heat transport can also be controlled by suitably adjusting the external and internal parameters of the system.
Chen, Weisheng; Li, Wei; Miao, Qiguang
2010-07-01
An adaptive backstepping tracking scheme is developed for a class of strict-feedback systems with unknown periodically time-varying parameters and unknown control gain functions. High-order neural network (HONN) and Fourier series expansion (FSE) are combined into a new function approximator to model each uncertain term in the system. The dynamic surface control (DSC) approach is used to solve the problem of 'explosion of complexity' in the backstepping design procedure. Nussbaum gain function (NGF) is employed to deal with the unknown control gain functions. The uniform boundedness of all closed-loop signals is guaranteed. The tracking error is proved to converge to a small residual set around the origin. Two simulation examples are provided to demonstrate the effectiveness of the control scheme designed in this paper.
Institute of Scientific and Technical Information of China (English)
周利; 郑严; 相建海
2001-01-01
The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985 - 1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985-1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.
DEFF Research Database (Denmark)
Allen, Matthew S.; Sracic, Michael W.; Chauhan, Shashank
2011-01-01
in the velocity of the wind with height and changes in the aerodynamics of the blades as they pass the tower. These effects may cause parametric resonance or other unexpected phenomena, so it is important to properly characterize them so that these machines can be designed to achieve high reliability, safety......, and to produce economical power. This work presents a system identification methodology that can be used to identify models for linear, periodically time-varying systems when the input forces are unmeasured, broadband and random. The methodology is demonstrated for the well-known Mathieu oscillator and then used...... to interrogate simulated measurements from a rotating wind turbine. The measurements were simulated for a 5 MW turbine modeled in the HAWC2 simulation code, which includes both structural dynamic and aerodynamic effects. This simulated system identification provides insights into the test and measurement...
Directory of Open Access Journals (Sweden)
mostafa gholamrezaii rahimi
2015-09-01
Full Text Available Production planning is one of the most important tasks of production and operations management and decides to determine the optimum amount of production, labor and inventory levels for each period of planning horizon with regard to productive resources and limits. This research presents a multi-product and multi-objective model of production planning with fuzzy parameters and soft constraints regarding the time value of money, inventory level, labor, capacity of machines and warehouse space. The proposed model attempts to maximize profit of the sale and minimize carrying and backordering costs and changes in labor levels. Case study conducted in the aluminum factory, shows the performance of this model comparing the current situation.
Directory of Open Access Journals (Sweden)
Naglaa H. El-Sodany
2011-01-01
Full Text Available Problem statement: This study treats the probabilistic safety stock n-items inventory system having varying holding cost and zero lead-time subject to linear constraint. Approach: The expected total cost is composed of three components: the average purchase cost; the expected order cost and the expected holding cost. Results: The policy variables for this model are the number of periods N*r and the optimal maximum inventory level Q*mr and the minimum expected total cost. Conclusion/Recommendations: We can obtain the optimal values of these policy variables by using the geometric programming approach. A special case is deduced and an illustrative numerical example is added.
Directory of Open Access Journals (Sweden)
Hardik N. Soni
2015-03-01
Full Text Available In this paper, an attempt has been made to develop a periodic review inventory model by considering lead-time and the backorder rate as control variables in fuzzy stochastic environment. Without loss of generality, we have assumed that all the observed values of the fuzzy random variable, representing the demand as triangular fuzzy numbers. The variance of fuzzy random demand is taken into consideration to give due attention to every fuzzy observations. The protection interval demand has also been assumed to be fuzzy stochastic. The expected shortages are calculated by using credibility criterion. For the proposed model, we provide a solution procedure incorporating numerical technique viz. Scan and zoom method to determine an optimal policy. A numerical example is taken up to illustrate the solution procedure and sensitivity analysis of the optimal solution with respect to the key parameters of the system is carried out.
Rumsey, John W; Das, Mainak; Kang, Jung-Fong; Wagner, Robert; Molnar, Peter; Hickman, James J
2008-03-01
While much is known about muscle spindle structure, innervation and function, relatively few factors have been identified that regulate intrafusal fiber differentiation and spindle development. Identification of these factors will be a crucial step in tissue engineering functional muscle systems. In this study, we investigated the role of the growth factor, neuregulin 1-beta-1 (Nrg 1-beta-1) EGF, for its ability to influence myotube fate specification in a defined culture system utilizing the non-biological substrate N-1[3-(trimethoxysilyl)propyl]-diethylenetriamine (DETA). Based on morphological and immunocytochemical criteria, Nrg 1-beta-1 treatment of developing myotubes increases the ratio of nuclear bag fibers to total myotubes from 0.019 to 0.100, approximately a five-fold increase. The myotube cultures were evaluated for expression of the intrafusal fiber-specific alpha cardiac-like myosin heavy chain and for the expression of the non-specific slow myosin heavy chain. Additionally, the expression of ErbB2 receptors on all myotubes was observed, while phosphorylated ErbB2 receptors were only observed in Nrg 1-beta-1-treated intrafusal fibers. After Nrg 1-beta-1 treatment, we were able to observe the expression of the intrafusal fiber-specific transcription factor Egr3 only in fibers exhibiting the nuclear bag phenotype. Finally, nuclear bag fibers were characterized electrophysiologically for the first time in vitro. This data shows conclusively, in a serum-free system, that Nrg 1-beta-1 is necessary to drive specification of forming myotubes to the nuclear bag phenotype.
Directory of Open Access Journals (Sweden)
Daniel Gachuiri Njau
2016-09-01
Full Text Available Frequently, forensic entomology is applied in the use of insect maggots for the identification of specimens or remains of humans. Maggot crop analysis could be valuable in criminal investigations when maggots are found at a crime scene and a corpse is absent. Human short tandem repeat (STR has previously been used to support the association of maggots to a specific corpse but not in the period at which the body has been decomposing. The aim of this research was to assess the time period for successful STR analyses of human DNA from third instar maggots (Protophormia terraenovae obtained from decomposing human corpses as well as to investigate the human DNA turnover and degradation in the maggot crop after they are removed from food and/or are fed on a beef (a new/different food source. Results showed that the amount of human DNA recovered from maggots decreased with time in all cases. For maggots fed on beef, the human DNA could only be recovered up to day two and up to day four for the starved maggots. STR analyses of human DNA from maggots’ crop content using 16 loci generated profiles that matched those of reference samples although some of the alleles were not amplifiable therefore generating partial profiles for the samples starved for 4 days and those fed on beef. This may be due to nuclease activity present in the gut of larvae that may have caused degradation of DNA and consequently reduction in DNA yield. It was possible to identify the decomposing body using STRs as markers.
Directory of Open Access Journals (Sweden)
Antonio Lobo
2005-06-01
Full Text Available Background: Comparative studies of dementia in different time periods are quite limited in the international literature, but might be useful to test environmental hypotheses. The aim of this study is to compare the prevalence of "organic brain syndrome", as a measure of dementia, in the elderly living in the same community in two different time periods and using the same methods. Methods: Representative samples of the elderly in the Zaragoza Study or ZARADEMP 0 (n= 1,080, completed the past decade, and now in Wave I of the ZARADEMP Project or ZARADEMP I (n= 4,803 were interviewed. The Geriatric Mental State (GMS was the main case-finding instrument and the results were analysed using the AGECAT diagnostic package to generate diagnoses. Results: Adjusted, total prevalence of "organic brain syndrome" in individuals aged 65 years and older has not varied from the previous decade. It was 8.4% in ZARADEMP I , and 7.4% in ZARADEMP 0 (prevalence ratio, PR = 0.83; CI 0.65-1.07. Adjusted prevalence among men was lower in ZARADEMP I (3.6% when compared to ZARADEMP 0 (5.5%, although the differences do not reach statistically significance (PR= 0.65; CI 0.41-1.05. However, in support of the working hypothesis, the differences were more marked, and we consider they reach statistically significant proportions in the age group 80-84 years. Conclusions: The prevalence of "organic brain syndrome" has not increased from the previous decade. On the contrary, the prevalence tends to be lower in men, and the differences reach stastistical significance in the age group 80-84 years. New analysis using diagnostic criteria of dementia in the same sample are required to confirm these findings.
Valentin-Silva, Adriano; Coelho, Victor Peçanha de Miranda; Ventrella, Marília Contin; Vieira, Milene Faria
2015-04-01
Dichogamy is a common characteristic among angiosperms, including Piper species. In this genus, the tiny flowers are morphologically similar and have an asynchronous stamen development. However, there is no information on the duration of stigma receptivity and whether it overlaps with pollen release. To better understand mechanisms of floral function in Piper vicosanum, we provide a detailed characterization of the timing of pollen release from the four stamens and the period of stigma receptivity and exposure mode of the receptive areas. We investigated plants of a natural population in a semideciduous seasonal forest (Viçosa, Minas Gerais State, southeastern Brazil), based on chemical tests, light microscopy, and scanning electron microscopy analyses. Incomplete protogyny-a mechanism that favors outcrossing-was recorded. The period of stigma receptivity was long (14 d), and the sequential exposure and senescence of stigmatic papillae occurred gradually and in a basipetal direction. Pollen release began 2-6 d after the beginning of the pistillate phase, with an average pollen viability of 87.7%, during the bisexual flower phase. Pollen was released for up to 6 d and occurred in one stamen at a time. The fruit set observed in tests of self-pollination indicated self-compatibility. The gradual and sequential exposure of stigmatic papillae in P. vicosanum flowers is described here as the mechanism for the long duration of receptivity. Anther development and pollen release were also sequential. These findings are yet unreported reproductive characteristics of the genus and offer new perspectives for future studies on the floral biology of other Piper species. © 2015 Botanical Society of America, Inc.
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A Cingolani
2012-11-01
Full Text Available Criteria of cART initiation after a first ADE have been modified over time based on evidence suggesting that treatment should be initiated earlier. The impact of these changes on clinical practice is unknown. Objective of this analysis was to evaluate temporal changes of time of starting cART after a first diagnosis of ADE in ART-naïve patients (pts. Methods: All HIV+ enrolled in ICONA Foundation Study who presented with a diagnosis of ADE while cART-naïve regardless of CD4 cell count were included. Pts were grouped according to have ADE for which additional medications that may have interactions with cART are required (Tb, atypical mycobacteriosis, non-Hodgkin lymphoma [group A], ADE treatable only by cART (PML, isosporidiasis/cryptosporidiasis, KS, wasting syndrome [group B] and ADE treatable with specific drugs (PCP, toxoplasmic encephalitis, CMV disease, esoph candidiasis, bacterial pneumonia, cervical cancer, cryptococcosis [group C]. Standard survival analysis by KM was used to estimate the cumulative percentage of pts starting cART, overall and after stratification for calendar period of diagnosis (1996–2000, 2001–2008, 2009–2011 and type of ADE (groups A, B, C. Multivariable Cox regression was used to investigate association between calendar year of ADE and time to cART initiation after controlling for demographics. Summary of results: A total of 715 pts with a first ADE were observed over 1996-2011 (group A, n=187; B, n=123; C, n=405. 519 (73% male, median age 38 (IQR:33–45, median CD4+64 (23–187/mm3 and HIV/RNA 5.25 (4.57–5.70 log10 cps/mL, with no differences by calendar period. By 30 days from ADE, 23% (95% CI: 19–27 of those diagnosed in 1996–2000 have started cART vs. 32% (95% CI: 25–39 in 2001–2008 and 36% (28–44 after 2009 (log-rank p=0.001. After stratifying by CD4 at ADE, 45% of pts with CD4<50/mm3, 30% of those with 51–200/mm3 and 16% of those>201/mm3 had started cART by 30 days (p<0.0001. Restricting
Research misconduct oversight: defining case costs.
Gammon, Elizabeth; Franzini, Luisa
2013-01-01
This study uses a sequential mixed method study design to define cost elements of research misconduct among faculty at academic medical centers. Using time driven activity based costing, the model estimates a per case cost for 17 cases of research misconduct reported by the Office of Research Integrity for the period of 2000-2005. Per case cost of research misconduct was found to range from $116,160 to $2,192,620. Research misconduct cost drivers are identified.
Espinar, B.; Blanc, P.; Wald, L.; Hoyer-Klick, C.; Schroedter-Homscheidt, M.; Wanderer, T.
2012-04-01
Meteorological data measured by ground stations are often a key element in the development and validation of methods exploiting satellite images. These data are considered as a reference against which satellite-derived estimates are compared. Long-term radiation and meteorological measurements are available from a large number of measuring stations. However, close examination of the data often reveals a lack of quality, often for extended periods of time. This lack of quality has been the reason, in many cases, of the rejection of large amount of available data. The quality data must be checked before their use in order to guarantee the inputs for the methods used in modelling, monitoring, forecast, etc. To control their quality, data should be submitted to several conditions or tests. After this checking, data that are not flagged by any of the test is released as a plausible data. In this work, it has been performed a bibliographical research of quality control tests for the common meteorological variables (ambient temperature, relative humidity and wind speed) and for the usual solar radiometrical variables (horizontal global and diffuse components of the solar radiation and the beam normal component). The different tests have been grouped according to the variable and the average time period (sub-hourly, hourly, daily and monthly averages). The quality test may be classified as follows: • Range checks: test that verify values are within a specific range. There are two types of range checks, those based on extrema and those based on rare observations. • Step check: test aimed at detecting unrealistic jumps or stagnation in the time series. • Consistency checks: test that verify the relationship between two or more time series. The gathered quality tests are applicable for all latitudes as they have not been optimized regionally nor seasonably with the aim of being generic. They have been applied to ground measurements in several geographic locations, what
Energy Technology Data Exchange (ETDEWEB)
Kramer, P [Theoretische Physik, University Tuebingen (Germany); Kramer, T [Institute for Theoretical Physics, University Regensburg (Germany); Man' ko, V I [Lebedev Physical Institute, Moscow (Russian Federation)], E-mail: peter.kramer@uni-tuebingen.de
2009-05-15
We consider classical and quantum propagators for two different time intervals. If these propagators follow one another in a Fibonacci sequence we get a discrete quasi-periodic system. A theorem due to Nielsen provides a novel conserved quantity for this system. The Nielsen quantity controls the transition between commutative and non-commutative propagation in time. The quasi-periodically kicked oscillator, moreover, is dominated by quasi-periodic analogues of the Floquet theorem.
Head, James
2017-04-01
Formation of Late Noachian-Early Hesperian (LN-EH) valley network systems (VNS) signaled the presence of warm/wet conditions generating several hypotheses for climates permissive of these conditions. To constrain options for the ambient Noachian climate, we examine estimates for time required to carve channels/deltas and total duration implied by plausible intermittencies. Formation Times for VN, OBL, Deltas, Fans: A synthesis of required timescales show that even with the longest estimated continuous duration of VN formation/intermittencies, total time to carve the VN does not exceed 106 years, 273 K, hydrological system vertically integrated, and rainfall occurs to recharge the aquifer. Two subtypes: a) "Rainfall/Fluvial Erosion-Dominated Warm and Wet Model": "Rainfall and surface runoff" persist throughout Noachian to explain crater degradation, and a LN-EH short rapidly ending terminal epoch. b) "Recharge Evaporation/Evaporite Dominated Warm and Wet Model": Sustained period of equatorial/mid-latitude precipitation and a vertically integrated hydrological system driven by evaporative upwelling and fluctuating shallow water table playa environments account for sulfate evaporate environments at Meridiani Planum. Sustained temperatures >273 K are required for extended periods (107-108 years). 2) Cold and icy climate: Sustained background temperatures extremely low (MAT ˜225 K), cryosphere is globally continuous, hydrological system is horizontally stratified, separating groundwater system from surface; no combination of spin-axis/orbital perturbations can raise MAT to 273 K. Adiabatic cooling effects transfer water to high altitudes, leading to "Late Noachian Icy Highlands Model". VNS cannot form in this nominal climate environment without special circumstances (e.g., impacts or volcanic eruptions elevate of temperatures by >˜50 K to induce melting and fluvial/lacustrine activity). 3) Cold and Icy climate warmed by greenhouse gases: The climate is sustained cold
Coward, Adrian V.; Papageorgiou, Demetrios T.; Smyrlis, Yiorgos S.
1994-01-01
In this paper the nonlinear stability of two-phase core-annular flow in a pipe is examined when the acting pressure gradient is modulated by time harmonic oscillations and viscosity stratification and interfacial tension is present. An exact solution of the Navier-Stokes equations is used as the background state to develop an asymptotic theory valid for thin annular layers, which leads to a novel nonlinear evolution describing the spatio-temporal evolution of the interface. The evolution equation is an extension of the equation found for constant pressure gradients and generalizes the Kuramoto-Sivashinsky equation with dispersive effects found by Papageorgiou, Maldarelli & Rumschitzki, Phys. Fluids A 2(3), 1990, pp. 340-352, to a similar system with time periodic coefficients. The distinct regimes of slow and moderate flow are considered and the corresponding evolution is derived. Certain solutions are described analytically in the neighborhood of the first bifurcation point by use of multiple scales asymptotics. Extensive numerical experiments, using dynamical systems ideas, are carried out in order to evaluate the effect of the oscillatory pressure gradient on the solutions in the presence of a constant pressure gradient.
Directory of Open Access Journals (Sweden)
Mohanty Paritosh
2011-01-01
Full Text Available Abstract We report the first synthesis of periodic mesoporous silicas templated by bicelles. The obtained materials form novel pillared lamellar structures with a high degree of periodic order, narrow pore size distributions, and exceptionally high surface areas.
Versini, P.-A.; Petrucci, G.; de Gouvello, B.
2014-09-01
Experimental green-roof rainfall-runoff observations have shown a positive impact on stormwater management at the building scale; with a decrease in the peak discharge and a decrease in runoff volume. This efficiency of green-roofs varies from one rainfall event to another depending on precipitation characteristics and substrate antecedent conditions. Due to this variability, currently, green-roofs are rarely officially used as a regulation tool to manage stormwater. Indeed, regulation rules governing the connection to the stormwater network are usually based on absolute threshold values that always have to be respected: maximum areal flow-rate or minimum retention volume for example. In this context, the aim of this study is to illustrate how a green-roof could represent an alternative to solve stormwater management issues, if the regulation rules were further based on statistics. For this purpose, a modelling scheme has been established at the parcel scale to simulate the hydrological response of several roof configurations: impervious, strictly regulated (in terms of areal flow-rate or retention volume), and covered by different types of green-roof matter. Simulations were carried out on a long precipitation time period (23 years) that included a large and heterogeneous set of hydrometeorological conditions. Results obtained for the different roof configurations were compared. Based on the return period of the rainfall event, the probability to respect some regulation rules (defined from real situations) was assessed. They illustrate that green-roofs reduce stormwater runoff compared to an impervious roof surface and can guarantee the respect of the regulation rules in most of the cases. Moreover, their implementation can appear more realistic than that of other infrastructures strictly complying with regulations and demanding significant storage capacity.
Minetti, S; Raffetti, E; Lodi-Rizzini, F; Facchetti, S; Schlanser, E; Colombo, E; Cinquini, M; Donato, F; Tosoni, C
2015-01-01
Migrants from developing to Western countries tend to become more sensitised to host than to origin country allergens, although substantial changes in migration patterns have occurred in recent decades. We investigated adult immigrants with respiratory allergy, first tested for allergic sensitisation between 1985 and 2012 in a highly industrialised area in Italy. A comparison was made of the sensitisation pattern between immigrants and a random sample of native-born subjects affected by a respiratory allergy, and among immigrants according to macro-region of origin and time period. Between 1985 and 2012, 480 immigrants with respiratory allergy had a first positive allergy test. Immigrants were sensitised mainly to grass (67.1%), house dust mites (HDM) (38.5%) and birch (27.5%), with a pattern of sensitisation very similar to that observed in Italians (native-born). An increase in the proportion of subjects with asthma and of subjects with polysensitisation was observed from the first (1985-2002) to the middle (2003-2007) and the most recent period (2008-2012). In recent years, the proportion of subjects with polysensitisation in immigrants is higher than in Italians (native-born) (53.3% vs. 40.1%). Among immigrants, the risk of sensitisation to grass was higher in those from Sub-Saharan Africa (odds ratio, OR=2.76) and Latin America (OR=2.49), whereas risk of sensitisation to HDM was higher among immigrants from South Asia (OR=2.71), compared to immigrants from Eastern Europe. Immigrants develop multiple sensitisations more frequently than native-born people, and are especially sensitised to local allergens; the country of origin seems to play a role. Copyright © 2014 SEICAP. Published by Elsevier Espana. All rights reserved.
Edelman, Theresa L. B.; McCulloch, Katherine A.; Barr, Angela; Frøkjær-Jensen, Christian; Jorgensen, Erik M.; Rougvie, Ann E.
2016-01-01
The Caenorhabditis elegans heterochronic gene pathway regulates the relative timing of events during postembryonic development. lin-42, the worm homolog of the circadian clock gene, period, is a critical element of this pathway. lin-42 function has been defined by a set of hypomorphic alleles that cause precocious phenotypes, in which later developmental events, such as the terminal differentiation of hypodermal cells, occur too early. A subset of alleles also reveals a significant role for lin-42 in molting; larval stages are lengthened and ecdysis often fails in these mutant animals. lin-42 is a complex locus, encoding overlapping and nonoverlapping isoforms. Although existing alleles that affect subsets of isoforms have illuminated important and distinct roles for this gene in developmental timing, molting, and the decision to enter the alternative dauer state, it is essential to have a null allele to understand all of the roles of lin-42 and its individual isoforms. To remedy this problem and discover the null phenotype, we engineered an allele that deletes the entire lin-42 protein-coding region. lin-42 null mutants are homozygously viable, but have more severe phenotypes than observed in previously characterized hypomorphic alleles. We also provide additional evidence for this conclusion by using the null allele as a base for reintroducing different isoforms, showing that each isoform can provide heterochronic and molting pathway activities. Transcript levels of the nonoverlapping isoforms appear to be under coordinate temporal regulation, despite being driven by independent promoters. The lin-42 null allele will continue to be an important tool for dissecting the functions of lin-42 in molting and developmental timing. PMID:27729432
Edelman, Theresa L B; McCulloch, Katherine A; Barr, Angela; Frøkjær-Jensen, Christian; Jorgensen, Erik M; Rougvie, Ann E
2016-12-07
The Caenorhabditis elegans heterochronic gene pathway regulates the relative timing of events during postembryonic development. lin-42, the worm homolog of the circadian clock gene, period, is a critical element of this pathway. lin-42 function has been defined by a set of hypomorphic alleles that cause precocious phenotypes, in which later developmental events, such as the terminal differentiation of hypodermal cells, occur too early. A subset of alleles also reveals a significant role for lin-42 in molting; larval stages are lengthened and ecdysis often fails in these mutant animals. lin-42 is a complex locus, encoding overlapping and nonoverlapping isoforms. Although existing alleles that affect subsets of isoforms have illuminated important and distinct roles for this gene in developmental timing, molting, and the decision to enter the alternative dauer state, it is essential to have a null allele to understand all of the roles of lin-42 and its individual isoforms. To remedy this problem and discover the null phenotype, we engineered an allele that deletes the entire lin-42 protein-coding region. lin-42 null mutants are homozygously viable, but have more severe phenotypes than observed in previously characterized hypomorphic alleles. We also provide additional evidence for this conclusion by using the null allele as a base for reintroducing different isoforms, showing that each isoform can provide heterochronic and molting pathway activities. Transcript levels of the nonoverlapping isoforms appear to be under coordinate temporal regulation, despite being driven by independent promoters. The lin-42 null allele will continue to be an important tool for dissecting the functions of lin-42 in molting and developmental timing.
Energy Technology Data Exchange (ETDEWEB)
Sjoegren, J.-U.; Andersson, S.; Olofsson, T. [Department of Applied Physics and Electronics, Umeaa University, SE-901 87 Umeaa (Sweden)
2009-07-15
In order to identify buildings that have energy saving potential there is a need for further development of robust methods for evaluation of energy performance as well as reliable key energy indicators. To be able to evaluate a large database of buildings, the evaluation has to be founded on available data, since an in-depth analysis of each building would require large measurement efforts in terms of both parameters and time. In practice, data are usually available for consumed energy, water, and so on, namely consumption that the tenants or property holder has to pay for. In order to evaluate the energy saving potential and energy management, interesting key energy indicators are the total heat loss coefficient K{sub tot} (W/K), the indoor temperature (T{sub i}), and the utilisation of the available heat (solar radiation and electricity primarily used for purposes other than heating). The total heat loss coefficient, K{sub tot}, is a measure of the heat lost through the building's envelope, whereas T{sub i} and the gained energy reflect the user's behaviour and efficiency of the control system. In this study, a linear regression approach (energy signature) has been used to analyse data for 2003-2006 for nine fairly new multifamily buildings located in the Stockholm area, Sweden. The buildings are heated by district heating and the electricity used is for household equipment and the buildings' technical systems. The data consist of monthly energy used for heating and outdoor temperature together with annual water use, and for some buildings data for household electricity are also available. For domestic hot water and electricity, monthly distributions have been assumed based on data from previous studies and energy companies. The impact on K{sub tot} and T{sub i} of the time period and assumed values for the utilised energy are investigated. The results show that the obtained value of K{sub tot} is rather insensitive to the time period and utilised
Software Defined Cyberinfrastructure
Energy Technology Data Exchange (ETDEWEB)
Foster, Ian; Blaiszik, Ben; Chard, Kyle; Chard, Ryan
2017-07-17
Within and across thousands of science labs, researchers and students struggle to manage data produced in experiments, simulations, and analyses. Largely manual research data lifecycle management processes mean that much time is wasted, research results are often irreproducible, and data sharing and reuse remain rare. In response, we propose a new approach to data lifecycle management in which researchers are empowered to define the actions to be performed at individual storage systems when data are created or modified: actions such as analysis, transformation, copying, and publication. We term this approach software-defined cyberinfrastructure because users can implement powerful data management policies by deploying rules to local storage systems, much as software-defined networking allows users to configure networks by deploying rules to switches.We argue that this approach can enable a new class of responsive distributed storage infrastructure that will accelerate research innovation by allowing any researcher to associate data workflows with data sources, whether local or remote, for such purposes as data ingest, characterization, indexing, and sharing. We report on early experiments with this approach in the context of experimental science, in which a simple if-trigger-then-action (IFTA) notation is used to define rules.
Owen, L.A.; Finkel, R.C.; Barnard, P.L.; Haizhou, Ma; Asahi, K.; Caffee, M.W.; Derbyshire, E.
2005-01-01
Temporal and spatial changes in glacier cover throughout the Late Quaternary in Tibet and the bordering mountains are poorly defined because of the inaccessibility and vastness of the region, and the lack of numerical dating. To help reconstruct the timing and extent of glaciation throughout Tibet and the bordering mountains, we use geomorphic mapping and 10Be cosmogenic radionuclide (CRN) surface dating in study areas in southeastern (Gonga Shan), southern (Karola Pass) and central (Western Nyainqentanggulha Shan and Tanggula Shan) Tibet, and we compare these with recently determined numerical chronologies in other parts of the plateau and its borderlands. Each of the study regions receives its precipitation mainly during the south Asian summer monsoon when it falls as snow at high altitudes. Gonga Shan receives the most precipitation (>2000 mm a-1) while, near the margins of monsoon influence, the Karola Pass receives moderate amounts of precipitation (500-600 mm a-1) and, in the interior of the plateau, little precipitation falls on the western Nyainqentanggulha Shan (???300 mm a -1) and the Tanggula Shan (400-700 mm a-1). The higher precipitation values for the Tanggula Shan are due to strong orographic effects. In each region, at least three sets of moraines and associated landforms are preserved, providing evidence for multiple glaciations. The 10Be CRN surface exposure dating shows that the formation of moraines in Gonga Shan occurred during the early-mid Holocene, Neoglacial and Little Ice Age, on the Karola Pass during the Lateglacial, Early Holocene and Neoglacial, in the Nyainqentanggulha Shan date during the early part of the last glacial cycle, global Last Glacial Maximum and Lateglacial, and on the Tanggula Shan during the penultimate glacial cycle and the early part of the last glacial cycle. The oldest moraine succession in each of these regions varies from the early Holocene (Gonga Shan), Lateglacial (Karola Pass), early Last Glacial (western
Worm, Signe W.; Bower, Mark; Reiss, Peter; Bonnet, Fabrice; Law, Matthew; Fätkenheuer, Gerd; d'Arminio Monforte, Antonella; Abrams, Donald I.; Grulich, Andrew; Fontas, Eric; Kirk, Ole; Furrer, Hansjakob; Wit, Stephane D.; Phillips, Andrew; Lundgren, Jens D.; Sabin, Caroline A.; Butcher, D.; Delforge, M.; Fanti, I.; Fontas, E.; Franquet, X.; Geffard, S.; Gras, L.; Helweg-Larsen, J.; Hillebregt, M.; Kamara, D.; Kjær, J.; Krum, E.; Lundgren, J.D.; McManus, H.; Meidahl, P.; Mocroft, A.; Nielsen, J.; Phillips, A.; Powderl, W.; Rickenbach, M.; Rode, R.; Ryom, L.; Sabin, C.A.; Salbøl Brandt, R.; Schmidt Iversen, J.; Shortman, N.; Sjøl, A.; Smith, C.; Torres, F.; Tverland, J.; Wright, S.; Zaheri, S.; de Wolf, F.; Smidt, J.; Ristola, M.; Katlama, C.; Viard, J-P.; Girard, P.-M.; Livrozet, J.M.; Vanhems, P.; Pradier, C.; Dabis, F.; Neau, D.; Rockstroh, J.; Schmidt, R.; Degen, O.; van Lunzen, J.; Stellbrink, H.J.; Staszewski, S.; Bogner, J.; Fätkenheuer, G.; Gargalianos, P.; Kosmidis, J.; Perdios, J.; Xylomenos, G.; Filandras, A.; Karabatsaki, E.; Panos, G.; Sambatakou, H.; Banhegyi, D.; Mulcahy, F.; Burke, M.; Turner, D.; Yust, I.; Hassoun, G.; Pollack, S.; Maayan, S.; Vella, S.; Esposito, R.; Mazeu, I.; Mussini, C.; Arici, C.; Pristera, R.; Gabbuti, A.; Mazzotta, F.; Lichtner, M.; Vullo, V.; Boer, K.; Geerlings, S.E.; Godfried, M.H.; Kuijpers, T.W.; Lange, J.M.A.; Nellen, F.J.B.; Pajkrt, D.; Prins, J.M.; Reiss, P.; Scherpbier, H.J.; Vrouenraets, S.M.E.; Wit, F.W.M.N.; van Vugt, M.; van der Meer, J.T.M.; van der Poll, T.; van der Valk, M.; Chirianni, A.; Gargiulo, M.; Montesarchio, E.; Antonucci, G.; Narciso, P.; Testa, A.; Vlassi, C.; Zaccarelli, M.; Castagna, A.; Gianotti, N.; Lazzarin, A.; Galli, M.; Ridolfo, A.; d'Arminio Monforte, A.; Rozentale, B.; Zeltina, I.; Chaplinskas, S.; Hemmer, R.; Staub, T.; Reiss, P.; Bruun, J.; Maeland, A.; Ormaasen, V.; Lowe, S.; Oude Lashof, A.; Schreij, G.; Gasiorowski, J.; Knysz, B.; Bakowska, E.; Horban, A.; Flisiak, R.; Grzeszczuk, A.; Boron-Kaczmarska, A.; Parczewski, M.; Pynka, M.; Beniowski, M.; Mularska, E.; Trocha, H.; Jablonowska, E.; Malolepsza, E.; Wojcik, K.; Antunes, F.; Caldeira, L.; Doroana, M.; Mansinho, K.; Maltez, F.; Bravenboer, B.; Pronk, M.J.H.; Duiculescu, D.; Rakhmanova, A.; Zakharova, N.; Buzunova, S.; Jevtovic, D.; Mokráš, M.; Staneková, D.; Tomazic, J.; González-Lahoz, J.; Labarga, P.; Medrano, J.; Soriano, V.; Moreno, S.; Rodriguez, J.M.; Bravo, I.; Clotet, B.; Jou, A.; Paredes, R.; Puig, J.; Tural, C.; Gelinck, L.B.S.; Nouwen, J.L.; Rijnders, B.J.A.; Schurink, C.A.M.; Slobbe, L.; Verbon, A.; de Vries-Sluijs, T.E.M.S.; van der Ende, Marchina E.; van der Feltz, M.; Gatell, J.M.; Miró, J.M.; Domingo, P.; Gutierrez, M.; Mateo, G.; Sambeat, M.A.; Karlsson, A.; Flamholc, L.; Ledergerber, B.; Weber, R.; Cavassini, M.; Francioli, P.; Boffi, E.; Hirschel, B.; Furrer, H.; Battegay, M.; Elzi, L.; Chentsova, N.; Kravchenko, E.; Driessen, G.J.A.; Hartwig, N.G.; Frolov, V.; Kutsyna, G.; Servitskiy, S.; Krasnov, M.; Barton, S.; Johnson, A.M.; Mercey, D.; Johnson, M.A.; Mocroft, A.; Phillips, A.; Murphy, M.; Scullard, G.; Weber, J.; Fisher, M.; Leen, C.; Branger, J.; Åkerlund, B.; Morfeldt, L.; Sundström., A.; Thulin, G.; Karlsson, A.; Koppel, K.; Flamholc, L.; Ho̊kangård, C.; Angarano, G.; Antinori, A.; Armignacco, O.; Castelli, F.; Cauda, R.; Di Perri, G.; Galli, M.; Iardino, R.; Ippolito, G.; Lazzarin, A.; Moroni, M.; Perno, C.F.; Viale, P.L.; Von Schlosser, F.; Ammassari, A.; Andreoni, M.; Antinori, A.; Balotta, C.; Bonfanti, P.; Bonora, S.; Borderi, M.; Capobianchi, M.R.; Castagna, A.; Ceccherini-Silberstein, F.; Cinque, P.; Cozzi-Lepri, A.; De Luca, A.; Gargiulo, M.; Gervasoni, C.; Girardi, E.; Gori, A.; Guaraldi, G.; Lichtner, M.; Lo Caputo, S.; Madeddu, G.; Maggiolo, F.; Marchetti, G.; Marcotullio, S.; Monno, L.; Murri, R.; Mussini, C.; Puoti, M.; Torti, C.; d'Arminio Monforte, A.; Cicconi, P.; Cozzi-Lepri, A.; Fanti, I.; Formenti, T.; Galli, L.; Lorenzini, P.; Costantini, A.; Giacometti, A.; Riva, A.; Angarano, G.; Carrisa, C.; Monno, L.; Lazzari, G.; Maggiolo, F.; Borderi, M.; Verucchi, G.; Viale, P.L.; Kauffmann, R.H.; Schippers, E.F.; Castelli, F.; Minardi, C.; Torti, C.; Abeli, C.; Quirino, T.; Manconi, P.E.; Piano, P.; Falasca, K.; Vecchiet, J.; Segala, D.; Sighinolfi, L.; Lo Caputo, S.; Mazzotta, F.; Alessandrini, A.; Cassola, G.; Mazzarello, G.; Piscopo, R.; Viscoli, G.; Belvisi, V.; Mastroianni, C.; Bonfanti, P.; Caramma, I.; Castelli, P.; Chiodera, A.; Alleman, M.A.; Bouwhuis, J.W.; Groeneveld, P.H.P.; Bigoloni, A.; Carenzi, L.; Castagna, A.; Cicconi, P.; Formenti, T.; Galli, A.; Galli, M.; Lazzarin, A.; Moioli, M.C.; Piolini, R.; Puoti, M.; Ridolfo, A.L.; Rizzardini, G.; Rossotti, R.; Salpietro, S.; Spagnuolo, V.; Zucchi, P.; d'Arminio Monforte, A.; Bisio, L.; Mussini, C.; Gori, A.; Lapadula, G.; Abrescia, N.; Chirianni, A.; Gargiulo, M.; Guida, M.G.; Baldelli, F.; Belfiori, B.; Parruti, G.; Ursini, T.; Magnani, G.; Ursitti, M.A.; Acinapura, R.; Andreoni, M.; Antinori, A.; Capozzi, M.; Cauda, R.; De Luca, A.; Gallo, L.; Libertone, R.; Lichtner, M.; Nicastro, E.; Tebano, G.; Tozzi, V.; Vullo, V.; Zaccarelli, M.; d'Avino, A.; Madeddu, G.; Mura, M.S.; Caramello, P.; Di Perri, G.; Orofino, G.C.; Sciandra, M.; Soetekouw, R.; ten Kate, R.W.; Manfrin, V.; Pellizzer, G.; Bernard, E.; Caissotti, C.; Cua, E.; De Salvador-Guillouet, F.; Dellamonica, P.; Dollet, K.; Durant, J.; Ferrando, S.; Fontas, E.; Mondain-Miton, V.; Naqvi, A.; Perbost, I.; Pillet, S.; Pradier, C.; Prouvost-Keller, B.; Pugliese, P.; Rahelinirina, V.; Roger, P.M.; Barth, J.; Battegay, M.; Bernasconi, E.; Böni, J.; Bucher, H.C.; Burton-Jeangros, C.; Calmy, A.; Cavassini, M.; Cellerai, C.; Dubs, R.; Egger, M.; Elzi, L.; Fehr, J.; Flepp, M.; Francioli, P.; Furrer, H.; Fux, C.A.; Gorgievski, M.; Günthard, H.; Hasse, B.; Hirsch, H.H.; Hirschel, B.; Hösli, I.; Kahlert, C.; Kaiser, L.; Keiser, O.; Kind, C.; Klimkait, T.; Kovari, H.; Ledergerber, B.; Martinetti, G.; Martinez de Tejada, B.; Müller, N.; Nadal, D.; Pantaleo, G.; Rauch, A.; Regenass, S.; Rickenbach, M.; Rudin, C.; Schmid, P.; Schöni-Affolter, F.; Schüpbach, J.; Schultze, D.; Speck, R.; Taffé, P.; Telenti, A.; Trkola, A.; Vernazza, P.; Weber, R.; Yerly, S.; von Wyl, V.; Arend, S.M.; Jolink, H.; Kroon, F.P.; de Boer, M.G.J.; van Dissel, J.T.; van Nieuwkoop, C.; van den Broek, P.J.; Pogany, K.; den Hollander, J.G.; Kortmann, W.; van Twillert, G.; Leyten, E.M.S.; Vriesendorp, R.; Kootstra, G.J.; ten Napel, C.H.H.; Blok, W.L.; Brinkman, K.; Frissen, P.H.J.; Schouten, W.E.M.; van den Berk, G.E.L.; Brouwer, A.E.; Juttmann, J.R.; van Kasteren, M.E.E.; Lettinga, K.D.; Veenstra, J.; Mulder, J.W.; Smit, P.M.; Weijer, S.; van Gorp, E.C.M.; Verhagen, D.W.M.; van Eeden, A.; Doedens, R.; Scholvinck, E.H.; Sprenger, H.G.; Stek, C.J.; van Assen, S.; Brouwer, A.M.; Dofferhoff, A.S.M.; Keuter, M.; Koopmans, P.P.; de Groot, R.; ter Hofstede, H.J.M.; van der Flier, M.; van der Ven, A.J.A.M.; Arends, J.E.; Ellerbroek, P.M.; Hoepelman, A.I.M.; Jaspers, C.A.J.J.; Maarschalk-Ellerbroek, L.J.; Mudrikova, T.; Oosterheert, J.J.; Peters, E.J.G.; Schneider, M.M.E.; Wassenberg, M.W.M.; van der Hilst, J.C.H.; Bierman, W.F.W.; Claessen, F.A.P.; Danner, S.A.; Perenboom, R.M.; bij de Vaate, E.A.; de Jong, E.V.; de Vocht, J.; van Agtmael, M.A.; Geelen, S.P.M.; Wolfs, T.F.W.; Gisolf, E.H.; Richter, J.P.; van der Berg, C.; Stegeman, A.; van den Berge, M.; Polée, M.B.; van Houte, D.P.F.; van Vonderen, M.G.A.; Duits, A.J.; Winkel, C.; Dabis, F.; Bonnet, F.; Chêne, G.; Dabis, F.; Dupon, M.; Fleury, H.; Lacoste, D.; Malvy, D.; Mercié, P.; Morlat, P.; Neau, D.; Pellegrin, I.; Pellegrin, J.L.; Thiébaut, R.; Titier, K.; Bruyand, M.; Chêne, G.; Dabis, F.; Lawson-Ayayi, S.; Thiébaut, R.; Wittkop, L.; Bernard, N.; Bonnal, F.; Bonnet, F.; Caunègre, L.; Cazanave, C.; Ceccaldi, J.; Chambon, D.; Chossat, I.; Courtaud, K.; Dauchy, F.A.; De Witte, S.; Duffau, P.; Dupon, M.; Dupont, A.; Dutronc, H.; Farbos, S.; Gaboriau, V.; Gemain, M.C.; Gerard, Y.; Greib, C.; Hessamfar, M.; Lacoste, D.; Lafarie-Castet, S.; Lataste, P.; Lazaro, E.; Longy-Boursier, M.; Malvy, D.; Meraud, J.P.; Mercié, P.; Monlun, E.; Morlat, P.; Neau, D.; Ochoa, A.; Pellegrin, J.L.; Pistone, T.; Ragnaud, J.M.; Receveur, M.C.; Roger-Schmeltz, J.; Tchamgoué, S.; Thibaut, P.; Vandenhende, M.A.; Viallard, J.F.; Moreau, J.F.; Pellegrin., I.; Fleury, H.; Lafon, M.E.; Masquelier, B.; Trimoulet, P.; Breilh, D.; Titier, K.; Haramburu, F.; Miremont-Salamé, G.; Blaizeau, M.J.; D'Ivernois, C.; Decoin, M.; Delaune, J.; Delveaux, S.; Hanappier, C.; Leleux, O.; Sicard, X.; Uwamaliya-Nziyumvira, B.; Geffard, S.; Leray, J.; Palmer, G.; Touchard, D.; Baker, D.; Bendall, C.; Bloch, M.; Carr, A.; Cooper, D.; Franic, T.; Law, M.; McManus, H.; Petoumenos, K.; Vale, R.; Wright, S.; Edwards, S.; Hoy, J.; Moore, R.; Nicholson, J.; Roth, N.; Watson, K.; Chuah, J.; Ngieng, M.; Nolan, D.; Skett, J.; Cadafalch, J.; Calvo, G.; Codina, C.; Del Cacho, E.; Domingo, P.; Fuster, M.; Gatell, J.; Mateu, S.; Sambeat, M.A.; Sirera, G.; Torres, F.; Vaqué, A.; Clumeck, N.; De Wit, S.; Delforge, M.; Gennotte, A.F.; Gerard, M.; Kabeya, K.; Konopnicki, D.; Libois, A.; Martin, C.; Necsoi, C.; Payen, M.C.; Semaille, P.; Van Laethem, Y.; Bartsch, G.; El-Sadr, W.M.; Krum, E.; Neaton, J.; Thompson, G.; Wentworth, D.; Luskin-Hawk, R.; Telzak, E.; El-Sadr, W.M.; Abrams, D.I.; Cohn, D.; Markowitz, N.; Arduino, R.; Mushatt, D.; Friedland, G.; Perez, G.; Tedaldi, E.; Fisher, E.; Gordin, F.; Crane, L.R.; Sampson, J.; Baxter, J.; Cozzi-Lepri, A.; Fischer, A.H.; Grint, D.; Kirk, O.; Kjaer, J.; Kowalska, J.; Lundgren, J.; Mocroft, A.; Nielsen, J.; Peters, L.; Podlekareva, D.; Reekie, J.; Tverland, J.; Elias, C.; Losso, M.; Vetter, N.; Zangerle, R.; Vetter, N.; Zangerle, R.; Karpov, I.; Vassilenko, A.; Mitsura, V.M.; Suetnov, O.; Clumeck, N.; De Wit, S.; Delforge, M.; Colebunders, R.; Vandekerckhove, L.; Hadziosmanovic, V.; Kostov, K.; Begovac, J.; Jilich, D.; Machala, L.; Sedlacek, D.; Benfield, T.; Kronborg, G.; Larsen, M.; Nielsen, J.; Gerstoft, J.; Hansen, A.-B.E.; Katzenstein, T.; Skinhøj, P.; Pedersen, C.; Ostergaard, L.; Zilmer, K.
2013-01-01
Background: Non-AIDS defining cancers (NADC) are an important cause of morbidity and mortality in HIV-positive individuals. Using data from a large international cohort of HIV-positive individuals, we described the incidence of NADC from 2004-2010, and described subsequent mortality and predictors
2015-03-26
SOFTWARE-DEFINED RADIO WITH FPGA PROCESSING THESIS Presented to the Faculty Department of Electrical and Computer Engineering... process images , implement an encryption algorithm or even to act as a general purpose microprocessor. An FPGA is typically chosen in an application where...and Processing . Masters thesis , Landshut University, November 1999. [15] R. Lyons. Understanding Digital Signal Processing . Upper Saddle River, NJ
Worm, Signe W.; Bower, Mark; Reiss, Peter; Bonnet, Fabrice; Law, Matthew; Fätkenheuer, Gerd; d'Arminio Monforte, Antonella; Abrams, Donald I.; Grulich, Andrew; Fontas, Eric; Kirk, Ole; Furrer, Hansjakob; Wit, Stephane D.; Phillips, Andrew; Lundgren, Jens D.; Sabin, Caroline A.; Butcher, D.; Delforge, M.; Fanti, I.; Fontas, E.; Franquet, X.; Geffard, S.; Gras, L.; Helweg-Larsen, J.; Hillebregt, M.; Kamara, D.; Kjær, J.; Krum, E.; Lundgren, J.D.; McManus, H.; Meidahl, P.; Mocroft, A.; Nielsen, J.; Phillips, A.; Powderl, W.; Rickenbach, M.; Rode, R.; Ryom, L.; Sabin, C.A.; Salbøl Brandt, R.; Schmidt Iversen, J.; Shortman, N.; Sjøl, A.; Smith, C.; Torres, F.; Tverland, J.; Wright, S.; Zaheri, S.; de Wolf, F.; Smidt, J.; Ristola, M.; Katlama, C.; Viard, J-P.; Girard, P.-M.; Livrozet, J.M.; Vanhems, P.; Pradier, C.; Dabis, F.; Neau, D.; Rockstroh, J.; Schmidt, R.; Degen, O.; van Lunzen, J.; Stellbrink, H.J.; Staszewski, S.; Bogner, J.; Fätkenheuer, G.; Gargalianos, P.; Kosmidis, J.; Perdios, J.; Xylomenos, G.; Filandras, A.; Karabatsaki, E.; Panos, G.; Sambatakou, H.; Banhegyi, D.; Mulcahy, F.; Burke, M.; Turner, D.; Yust, I.; Hassoun, G.; Pollack, S.; Maayan, S.; Vella, S.; Esposito, R.; Mazeu, I.; Mussini, C.; Arici, C.; Pristera, R.; Gabbuti, A.; Mazzotta, F.; Lichtner, M.; Vullo, V.; Boer, K.; Geerlings, S.E.; Godfried, M.H.; Kuijpers, T.W.; Lange, J.M.A.; Nellen, F.J.B.; Pajkrt, D.; Prins, J.M.; Reiss, P.; Scherpbier, H.J.; Vrouenraets, S.M.E.; Wit, F.W.M.N.; van Vugt, M.; van der Meer, J.T.M.; van der Poll, T.; van der Valk, M.; Chirianni, A.; Gargiulo, M.; Montesarchio, E.; Antonucci, G.; Narciso, P.; Testa, A.; Vlassi, C.; Zaccarelli, M.; Castagna, A.; Gianotti, N.; Lazzarin, A.; Galli, M.; Ridolfo, A.; d'Arminio Monforte, A.; Rozentale, B.; Zeltina, I.; Chaplinskas, S.; Hemmer, R.; Staub, T.; Reiss, P.; Bruun, J.; Maeland, A.; Ormaasen, V.; Lowe, S.; Oude Lashof, A.; Schreij, G.; Gasiorowski, J.; Knysz, B.; Bakowska, E.; Horban, A.; Flisiak, R.; Grzeszczuk, A.; Boron-Kaczmarska, A.; Parczewski, M.; Pynka, M.; Beniowski, M.; Mularska, E.; Trocha, H.; Jablonowska, E.; Malolepsza, E.; Wojcik, K.; Antunes, F.; Caldeira, L.; Doroana, M.; Mansinho, K.; Maltez, F.; Bravenboer, B.; Pronk, M.J.H.; Duiculescu, D.; Rakhmanova, A.; Zakharova, N.; Buzunova, S.; Jevtovic, D.; Mokráš, M.; Staneková, D.; Tomazic, J.; González-Lahoz, J.; Labarga, P.; Medrano, J.; Soriano, V.; Moreno, S.; Rodriguez, J.M.; Bravo, I.; Clotet, B.; Jou, A.; Paredes, R.; Puig, J.; Tural, C.; Gelinck, L.B.S.; Nouwen, J.L.; Rijnders, B.J.A.; Schurink, C.A.M.; Slobbe, L.; Verbon, A.; de Vries-Sluijs, T.E.M.S.; van der Ende, Marchina E.; van der Feltz, M.; Gatell, J.M.; Miró, J.M.; Domingo, P.; Gutierrez, M.; Mateo, G.; Sambeat, M.A.; Karlsson, A.; Flamholc, L.; Ledergerber, B.; Weber, R.; Cavassini, M.; Francioli, P.; Boffi, E.; Hirschel, B.; Furrer, H.; Battegay, M.; Elzi, L.; Chentsova, N.; Kravchenko, E.; Driessen, G.J.A.; Hartwig, N.G.; Frolov, V.; Kutsyna, G.; Servitskiy, S.; Krasnov, M.; Barton, S.; Johnson, A.M.; Mercey, D.; Johnson, M.A.; Mocroft, A.; Phillips, A.; Murphy, M.; Scullard, G.; Weber, J.; Fisher, M.; Leen, C.; Branger, J.; Åkerlund, B.; Morfeldt, L.; Sundström., A.; Thulin, G.; Karlsson, A.; Koppel, K.; Flamholc, L.; Ho̊kangård, C.; Angarano, G.; Antinori, A.; Armignacco, O.; Castelli, F.; Cauda, R.; Di Perri, G.; Galli, M.; Iardino, R.; Ippolito, G.; Lazzarin, A.; Moroni, M.; Perno, C.F.; Viale, P.L.; Von Schlosser, F.; Ammassari, A.; Andreoni, M.; Antinori, A.; Balotta, C.; Bonfanti, P.; Bonora, S.; Borderi, M.; Capobianchi, M.R.; Castagna, A.; Ceccherini-Silberstein, F.; Cinque, P.; Cozzi-Lepri, A.; De Luca, A.; Gargiulo, M.; Gervasoni, C.; Girardi, E.; Gori, A.; Guaraldi, G.; Lichtner, M.; Lo Caputo, S.; Madeddu, G.; Maggiolo, F.; Marchetti, G.; Marcotullio, S.; Monno, L.; Murri, R.; Mussini, C.; Puoti, M.; Torti, C.; d'Arminio Monforte, A.; Cicconi, P.; Cozzi-Lepri, A.; Fanti, I.; Formenti, T.; Galli, L.; Lorenzini, P.; Costantini, A.; Giacometti, A.; Riva, A.; Angarano, G.; Carrisa, C.; Monno, L.; Lazzari, G.; Maggiolo, F.; Borderi, M.; Verucchi, G.; Viale, P.L.; Kauffmann, R.H.; Schippers, E.F.; Castelli, F.; Minardi, C.; Torti, C.; Abeli, C.; Quirino, T.; Manconi, P.E.; Piano, P.; Falasca, K.; Vecchiet, J.; Segala, D.; Sighinolfi, L.; Lo Caputo, S.; Mazzotta, F.; Alessandrini, A.; Cassola, G.; Mazzarello, G.; Piscopo, R.; Viscoli, G.; Belvisi, V.; Mastroianni, C.; Bonfanti, P.; Caramma, I.; Castelli, P.; Chiodera, A.; Alleman, M.A.; Bouwhuis, J.W.; Groeneveld, P.H.P.; Bigoloni, A.; Carenzi, L.; Castagna, A.; Cicconi, P.; Formenti, T.; Galli, A.; Galli, M.; Lazzarin, A.; Moioli, M.C.; Piolini, R.; Puoti, M.; Ridolfo, A.L.; Rizzardini, G.; Rossotti, R.; Salpietro, S.; Spagnuolo, V.; Zucchi, P.; d'Arminio Monforte, A.; Bisio, L.; Mussini, C.; Gori, A.; Lapadula, G.; Abrescia, N.; Chirianni, A.; Gargiulo, M.; Guida, M.G.; Baldelli, F.; Belfiori, B.; Parruti, G.; Ursini, T.; Magnani, G.; Ursitti, M.A.; Acinapura, R.; Andreoni, M.; Antinori, A.; Capozzi, M.; Cauda, R.; De Luca, A.; Gallo, L.; Libertone, R.; Lichtner, M.; Nicastro, E.; Tebano, G.; Tozzi, V.; Vullo, V.; Zaccarelli, M.; d'Avino, A.; Madeddu, G.; Mura, M.S.; Caramello, P.; Di Perri, G.; Orofino, G.C.; Sciandra, M.; Soetekouw, R.; ten Kate, R.W.; Manfrin, V.; Pellizzer, G.; Bernard, E.; Caissotti, C.; Cua, E.; De Salvador-Guillouet, F.; Dellamonica, P.; Dollet, K.; Durant, J.; Ferrando, S.; Fontas, E.; Mondain-Miton, V.; Naqvi, A.; Perbost, I.; Pillet, S.; Pradier, C.; Prouvost-Keller, B.; Pugliese, P.; Rahelinirina, V.; Roger, P.M.; Barth, J.; Battegay, M.; Bernasconi, E.; Böni, J.; Bucher, H.C.; Burton-Jeangros, C.; Calmy, A.; Cavassini, M.; Cellerai, C.; Dubs, R.; Egger, M.; Elzi, L.; Fehr, J.; Flepp, M.; Francioli, P.; Furrer, H.; Fux, C.A.; Gorgievski, M.; Günthard, H.; Hasse, B.; Hirsch, H.H.; Hirschel, B.; Hösli, I.; Kahlert, C.; Kaiser, L.; Keiser, O.; Kind, C.; Klimkait, T.; Kovari, H.; Ledergerber, B.; Martinetti, G.; Martinez de Tejada, B.; Müller, N.; Nadal, D.; Pantaleo, G.; Rauch, A.; Regenass, S.; Rickenbach, M.; Rudin, C.; Schmid, P.; Schöni-Affolter, F.; Schüpbach, J.; Schultze, D.; Speck, R.; Taffé, P.; Telenti, A.; Trkola, A.; Vernazza, P.; Weber, R.; Yerly, S.; von Wyl, V.; Arend, S.M.; Jolink, H.; Kroon, F.P.; de Boer, M.G.J.; van Dissel, J.T.; van Nieuwkoop, C.; van den Broek, P.J.; Pogany, K.; den Hollander, J.G.; Kortmann, W.; van Twillert, G.; Leyten, E.M.S.; Vriesendorp, R.; Kootstra, G.J.; ten Napel, C.H.H.; Blok, W.L.; Brinkman, K.; Frissen, P.H.J.; Schouten, W.E.M.; van den Berk, G.E.L.; Brouwer, A.E.; Juttmann, J.R.; van Kasteren, M.E.E.; Lettinga, K.D.; Veenstra, J.; Mulder, J.W.; Smit, P.M.; Weijer, S.; van Gorp, E.C.M.; Verhagen, D.W.M.; van Eeden, A.; Doedens, R.; Scholvinck, E.H.; Sprenger, H.G.; Stek, C.J.; van Assen, S.; Brouwer, A.M.; Dofferhoff, A.S.M.; Keuter, M.; Koopmans, P.P.; de Groot, R.; ter Hofstede, H.J.M.; van der Flier, M.; van der Ven, A.J.A.M.; Arends, J.E.; Ellerbroek, P.M.; Hoepelman, A.I.M.; Jaspers, C.A.J.J.; Maarschalk-Ellerbroek, L.J.; Mudrikova, T.; Oosterheert, J.J.; Peters, E.J.G.; Schneider, M.M.E.; Wassenberg, M.W.M.; van der Hilst, J.C.H.; Bierman, W.F.W.; Claessen, F.A.P.; Danner, S.A.; Perenboom, R.M.; bij de Vaate, E.A.; de Jong, E.V.; de Vocht, J.; van Agtmael, M.A.; Geelen, S.P.M.; Wolfs, T.F.W.; Gisolf, E.H.; Richter, J.P.; van der Berg, C.; Stegeman, A.; van den Berge, M.; Polée, M.B.; van Houte, D.P.F.; van Vonderen, M.G.A.; Duits, A.J.; Winkel, C.; Dabis, F.; Bonnet, F.; Chêne, G.; Dabis, F.; Dupon, M.; Fleury, H.; Lacoste, D.; Malvy, D.; Mercié, P.; Morlat, P.; Neau, D.; Pellegrin, I.; Pellegrin, J.L.; Thiébaut, R.; Titier, K.; Bruyand, M.; Chêne, G.; Dabis, F.; Lawson-Ayayi, S.; Thiébaut, R.; Wittkop, L.; Bernard, N.; Bonnal, F.; Bonnet, F.; Caunègre, L.; Cazanave, C.; Ceccaldi, J.; Chambon, D.; Chossat, I.; Courtaud, K.; Dauchy, F.A.; De Witte, S.; Duffau, P.; Dupon, M.; Dupont, A.; Dutronc, H.; Farbos, S.; Gaboriau, V.; Gemain, M.C.; Gerard, Y.; Greib, C.; Hessamfar, M.; Lacoste, D.; Lafarie-Castet, S.; Lataste, P.; Lazaro, E.; Longy-Boursier, M.; Malvy, D.; Meraud, J.P.; Mercié, P.; Monlun, E.; Morlat, P.; Neau, D.; Ochoa, A.; Pellegrin, J.L.; Pistone, T.; Ragnaud, J.M.; Receveur, M.C.; Roger-Schmeltz, J.; Tchamgoué, S.; Thibaut, P.; Vandenhende, M.A.; Viallard, J.F.; Moreau, J.F.; Pellegrin., I.; Fleury, H.; Lafon, M.E.; Masquelier, B.; Trimoulet, P.; Breilh, D.; Titier, K.; Haramburu, F.; Miremont-Salamé, G.; Blaizeau, M.J.; D'Ivernois, C.; Decoin, M.; Delaune, J.; Delveaux, S.; Hanappier, C.; Leleux, O.; Sicard, X.; Uwamaliya-Nziyumvira, B.; Geffard, S.; Leray, J.; Palmer, G.; Touchard, D.; Baker, D.; Bendall, C.; Bloch, M.; Carr, A.; Cooper, D.; Franic, T.; Law, M.; McManus, H.; Petoumenos, K.; Vale, R.; Wright, S.; Edwards, S.; Hoy, J.; Moore, R.; Nicholson, J.; Roth, N.; Watson, K.; Chuah, J.; Ngieng, M.; Nolan, D.; Skett, J.; Cadafalch, J.; Calvo, G.; Codina, C.; Del Cacho, E.; Domingo, P.; Fuster, M.; Gatell, J.; Mateu, S.; Sambeat, M.A.; Sirera, G.; Torres, F.; Vaqué, A.; Clumeck, N.; De Wit, S.; Delforge, M.; Gennotte, A.F.; Gerard, M.; Kabeya, K.; Konopnicki, D.; Libois, A.; Martin, C.; Necsoi, C.; Payen, M.C.; Semaille, P.; Van Laethem, Y.; Bartsch, G.; El-Sadr, W.M.; Krum, E.; Neaton, J.; Thompson, G.; Wentworth, D.; Luskin-Hawk, R.; Telzak, E.; El-Sadr, W.M.; Abrams, D.I.; Cohn, D.; Markowitz, N.; Arduino, R.; Mushatt, D.; Friedland, G.; Perez, G.; Tedaldi, E.; Fisher, E.; Gordin, F.; Crane, L.R.; Sampson, J.; Baxter, J.; Cozzi-Lepri, A.; Fischer, A.H.; Grint, D.; Kirk, O.; Kjaer, J.; Kowalska, J.; Lundgren, J.; Mocroft, A.; Nielsen, J.; Peters, L.; Podlekareva, D.; Reekie, J.; Tverland, J.; Elias, C.; Losso, M.; Vetter, N.; Zangerle, R.; Vetter, N.; Zangerle, R.; Karpov, I.; Vassilenko, A.; Mitsura, V.M.; Suetnov, O.; Clumeck, N.; De Wit, S.; Delforge, M.; Colebunders, R.; Vandekerckhove, L.; Hadziosmanovic, V.; Kostov, K.; Begovac, J.; Jilich, D.; Machala, L.; Sedlacek, D.; Benfield, T.; Kronborg, G.; Larsen, M.; Nielsen, J.; Gerstoft, J.; Hansen, A.-B.E.; Katzenstein, T.; Skinhøj, P.; Pedersen, C.; Ostergaard, L.; Zilmer, K.
2013-01-01
Background: Non-AIDS defining cancers (NADC) are an important cause of morbidity and mortality in HIV-positive individuals. Using data from a large international cohort of HIV-positive individuals, we described the incidence of NADC from 2004-2010, and described subsequent mortality and predictors o
Worm, Signe W.; Bower, Mark; Reiss, Peter; Bonnet, Fabrice; Law, Matthew; Fätkenheuer, Gerd; d'Arminio Monforte, Antonella; Abrams, Donald I.; Grulich, Andrew; Fontas, Eric; Kirk, Ole; Furrer, Hansjakob; Wit, Stephane D.; Phillips, Andrew; Lundgren, Jens D.; Sabin, Caroline A.; Butcher, D.; Delforge, M.; Fanti, I.; Fontas, E.; Franquet, X.; Geffard, S.; Gras, L.; Helweg-Larsen, J.; Hillebregt, M.; Kamara, D.; Kjær, J.; Krum, E.; Lundgren, J.D.; McManus, H.; Meidahl, P.; Mocroft, A.; Nielsen, J.; Phillips, A.; Powderl, W.; Rickenbach, M.; Rode, R.; Ryom, L.; Sabin, C.A.; Salbøl Brandt, R.; Schmidt Iversen, J.; Shortman, N.; Sjøl, A.; Smith, C.; Torres, F.; Tverland, J.; Wright, S.; Zaheri, S.; de Wolf, F.; Smidt, J.; Ristola, M.; Katlama, C.; Viard, J-P.; Girard, P.-M.; Livrozet, J.M.; Vanhems, P.; Pradier, C.; Dabis, F.; Neau, D.; Rockstroh, J.; Schmidt, R.; Degen, O.; van Lunzen, J.; Stellbrink, H.J.; Staszewski, S.; Bogner, J.; Fätkenheuer, G.; Gargalianos, P.; Kosmidis, J.; Perdios, J.; Xylomenos, G.; Filandras, A.; Karabatsaki, E.; Panos, G.; Sambatakou, H.; Banhegyi, D.; Mulcahy, F.; Burke, M.; Turner, D.; Yust, I.; Hassoun, G.; Pollack, S.; Maayan, S.; Vella, S.; Esposito, R.; Mazeu, I.; Mussini, C.; Arici, C.; Pristera, R.; Gabbuti, A.; Mazzotta, F.; Lichtner, M.; Vullo, V.; Boer, K.; Geerlings, S.E.; Godfried, M.H.; Kuijpers, T.W.; Lange, J.M.A.; Nellen, F.J.B.; Pajkrt, D.; Prins, J.M.; Reiss, P.; Scherpbier, H.J.; Vrouenraets, S.M.E.; Wit, F.W.M.N.; van Vugt, M.; van der Meer, J.T.M.; van der Poll, T.; van der Valk, M.; Chirianni, A.; Gargiulo, M.; Montesarchio, E.; Antonucci, G.; Narciso, P.; Testa, A.; Vlassi, C.; Zaccarelli, M.; Castagna, A.; Gianotti, N.; Lazzarin, A.; Galli, M.; Ridolfo, A.; d'Arminio Monforte, A.; Rozentale, B.; Zeltina, I.; Chaplinskas, S.; Hemmer, R.; Staub, T.; Reiss, P.; Bruun, J.; Maeland, A.; Ormaasen, V.; Lowe, S.; Oude Lashof, A.; Schreij, G.; Gasiorowski, J.; Knysz, B.; Bakowska, E.; Horban, A.; Flisiak, R.; Grzeszczuk, A.; Boron-Kaczmarska, A.; Parczewski, M.; Pynka, M.; Beniowski, M.; Mularska, E.; Trocha, H.; Jablonowska, E.; Malolepsza, E.; Wojcik, K.; Antunes, F.; Caldeira, L.; Doroana, M.; Mansinho, K.; Maltez, F.; Bravenboer, B.; Pronk, M.J.H.; Duiculescu, D.; Rakhmanova, A.; Zakharova, N.; Buzunova, S.; Jevtovic, D.; Mokráš, M.; Staneková, D.; Tomazic, J.; González-Lahoz, J.; Labarga, P.; Medrano, J.; Soriano, V.; Moreno, S.; Rodriguez, J.M.; Bravo, I.; Clotet, B.; Jou, A.; Paredes, R.; Puig, J.; Tural, C.; Gelinck, L.B.S.; Nouwen, J.L.; Rijnders, B.J.A.; Schurink, C.A.M.; Slobbe, L.; Verbon, A.; de Vries-Sluijs, T.E.M.S.; van der Ende, Marchina E.; van der Feltz, M.; Gatell, J.M.; Miró, J.M.; Domingo, P.; Gutierrez, M.; Mateo, G.; Sambeat, M.A.; Karlsson, A.; Flamholc, L.; Ledergerber, B.; Weber, R.; Cavassini, M.; Francioli, P.; Boffi, E.; Hirschel, B.; Furrer, H.; Battegay, M.; Elzi, L.; Chentsova, N.; Kravchenko, E.; Driessen, G.J.A.; Hartwig, N.G.; Frolov, V.; Kutsyna, G.; Servitskiy, S.; Krasnov, M.; Barton, S.; Johnson, A.M.; Mercey, D.; Johnson, M.A.; Mocroft, A.; Phillips, A.; Murphy, M.; Scullard, G.; Weber, J.; Fisher, M.; Leen, C.; Branger, J.; Åkerlund, B.; Morfeldt, L.; Sundström., A.; Thulin, G.; Karlsson, A.; Koppel, K.; Flamholc, L.; Ho̊kangård, C.; Angarano, G.; Antinori, A.; Armignacco, O.; Castelli, F.; Cauda, R.; Di Perri, G.; Galli, M.; Iardino, R.; Ippolito, G.; Lazzarin, A.; Moroni, M.; Perno, C.F.; Viale, P.L.; Von Schlosser, F.; Ammassari, A.; Andreoni, M.; Antinori, A.; Balotta, C.; Bonfanti, P.; Bonora, S.; Borderi, M.; Capobianchi, M.R.; Castagna, A.; Ceccherini-Silberstein, F.; Cinque, P.; Cozzi-Lepri, A.; De Luca, A.; Gargiulo, M.; Gervasoni, C.; Girardi, E.; Gori, A.; Guaraldi, G.; Lichtner, M.; Lo Caputo, S.; Madeddu, G.; Maggiolo, F.; Marchetti, G.; Marcotullio, S.; Monno, L.; Murri, R.; Mussini, C.; Puoti, M.; Torti, C.; d'Arminio Monforte, A.; Cicconi, P.; Cozzi-Lepri, A.; Fanti, I.; Formenti, T.; Galli, L.; Lorenzini, P.; Costantini, A.; Giacometti, A.; Riva, A.; Angarano, G.; Carrisa, C.; Monno, L.; Lazzari, G.; Maggiolo, F.; Borderi, M.; Verucchi, G.; Viale, P.L.; Kauffmann, R.H.; Schippers, E.F.; Castelli, F.; Minardi, C.; Torti, C.; Abeli, C.; Quirino, T.; Manconi, P.E.; Piano, P.; Falasca, K.; Vecchiet, J.; Segala, D.; Sighinolfi, L.; Lo Caputo, S.; Mazzotta, F.; Alessandrini, A.; Cassola, G.; Mazzarello, G.; Piscopo, R.; Viscoli, G.; Belvisi, V.; Mastroianni, C.; Bonfanti, P.; Caramma, I.; Castelli, P.; Chiodera, A.; Alleman, M.A.; Bouwhuis, J.W.; Groeneveld, P.H.P.; Bigoloni, A.; Carenzi, L.; Castagna, A.; Cicconi, P.; Formenti, T.; Galli, A.; Galli, M.; Lazzarin, A.; Moioli, M.C.; Piolini, R.; Puoti, M.; Ridolfo, A.L.; Rizzardini, G.; Rossotti, R.; Salpietro, S.; Spagnuolo, V.; Zucchi, P.; d'Arminio Monforte, A.; Bisio, L.; Mussini, C.; Gori, A.; Lapadula, G.; Abrescia, N.; Chirianni, A.; Gargiulo, M.; Guida, M.G.; Baldelli, F.; Belfiori, B.; Parruti, G.; Ursini, T.; Magnani, G.; Ursitti, M.A.; Acinapura, R.; Andreoni, M.; Antinori, A.; Capozzi, M.; Cauda, R.; De Luca, A.; Gallo, L.; Libertone, R.; Lichtner, M.; Nicastro, E.; Tebano, G.; Tozzi, V.; Vullo, V.; Zaccarelli, M.; d'Avino, A.; Madeddu, G.; Mura, M.S.; Caramello, P.; Di Perri, G.; Orofino, G.C.; Sciandra, M.; Soetekouw, R.; ten Kate, R.W.; Manfrin, V.; Pellizzer, G.; Bernard, E.; Caissotti, C.; Cua, E.; De Salvador-Guillouet, F.; Dellamonica, P.; Dollet, K.; Durant, J.; Ferrando, S.; Fontas, E.; Mondain-Miton, V.; Naqvi, A.; Perbost, I.; Pillet, S.; Pradier, C.; Prouvost-Keller, B.; Pugliese, P.; Rahelinirina, V.; Roger, P.M.; Barth, J.; Battegay, M.; Bernasconi, E.; Böni, J.; Bucher, H.C.; Burton-Jeangros, C.; Calmy, A.; Cavassini, M.; Cellerai, C.; Dubs, R.; Egger, M.; Elzi, L.; Fehr, J.; Flepp, M.; Francioli, P.; Furrer, H.; Fux, C.A.; Gorgievski, M.; Günthard, H.; Hasse, B.; Hirsch, H.H.; Hirschel, B.; Hösli, I.; Kahlert, C.; Kaiser, L.; Keiser, O.; Kind, C.; Klimkait, T.; Kovari, H.; Ledergerber, B.; Martinetti, G.; Martinez de Tejada, B.; Müller, N.; Nadal, D.; Pantaleo, G.; Rauch, A.; Regenass, S.; Rickenbach, M.; Rudin, C.; Schmid, P.; Schöni-Affolter, F.; Schüpbach, J.; Schultze, D.; Speck, R.; Taffé, P.; Telenti, A.; Trkola, A.; Vernazza, P.; Weber, R.; Yerly, S.; von Wyl, V.; Arend, S.M.; Jolink, H.; Kroon, F.P.; de Boer, M.G.J.; van Dissel, J.T.; van Nieuwkoop, C.; van den Broek, P.J.; Pogany, K.; den Hollander, J.G.; Kortmann, W.; van Twillert, G.; Leyten, E.M.S.; Vriesendorp, R.; Kootstra, G.J.; ten Napel, C.H.H.; Blok, W.L.; Brinkman, K.; Frissen, P.H.J.; Schouten, W.E.M.; van den Berk, G.E.L.; Brouwer, A.E.; Juttmann, J.R.; van Kasteren, M.E.E.; Lettinga, K.D.; Veenstra, J.; Mulder, J.W.; Smit, P.M.; Weijer, S.; van Gorp, E.C.M.; Verhagen, D.W.M.; van Eeden, A.; Doedens, R.; Scholvinck, E.H.; Sprenger, H.G.; Stek, C.J.; van Assen, S.; Brouwer, A.M.; Dofferhoff, A.S.M.; Keuter, M.; Koopmans, P.P.; de Groot, R.; ter Hofstede, H.J.M.; van der Flier, M.; van der Ven, A.J.A.M.; Arends, J.E.; Ellerbroek, P.M.; Hoepelman, A.I.M.; Jaspers, C.A.J.J.; Maarschalk-Ellerbroek, L.J.; Mudrikova, T.; Oosterheert, J.J.; Peters, E.J.G.; Schneider, M.M.E.; Wassenberg, M.W.M.; van der Hilst, J.C.H.; Bierman, W.F.W.; Claessen, F.A.P.; Danner, S.A.; Perenboom, R.M.; bij de Vaate, E.A.; de Jong, E.V.; de Vocht, J.; van Agtmael, M.A.; Geelen, S.P.M.; Wolfs, T.F.W.; Gisolf, E.H.; Richter, J.P.; van der Berg, C.; Stegeman, A.; van den Berge, M.; Polée, M.B.; van Houte, D.P.F.; van Vonderen, M.G.A.; Duits, A.J.; Winkel, C.; Dabis, F.; Bonnet, F.; Chêne, G.; Dabis, F.; Dupon, M.; Fleury, H.; Lacoste, D.; Malvy, D.; Mercié, P.; Morlat, P.; Neau, D.; Pellegrin, I.; Pellegrin, J.L.; Thiébaut, R.; Titier, K.; Bruyand, M.; Chêne, G.; Dabis, F.; Lawson-Ayayi, S.; Thiébaut, R.; Wittkop, L.; Bernard, N.; Bonnal, F.; Bonnet, F.; Caunègre, L.; Cazanave, C.; Ceccaldi, J.; Chambon, D.; Chossat, I.; Courtaud, K.; Dauchy, F.A.; De Witte, S.; Duffau, P.; Dupon, M.; Dupont, A.; Dutronc, H.; Farbos, S.; Gaboriau, V.; Gemain, M.C.; Gerard, Y.; Greib, C.; Hessamfar, M.; Lacoste, D.; Lafarie-Castet, S.; Lataste, P.; Lazaro, E.; Longy-Boursier, M.; Malvy, D.; Meraud, J.P.; Mercié, P.; Monlun, E.; Morlat, P.; Neau, D.; Ochoa, A.; Pellegrin, J.L.; Pistone, T.; Ragnaud, J.M.; Receveur, M.C.; Roger-Schmeltz, J.; Tchamgoué, S.; Thibaut, P.; Vandenhende, M.A.; Viallard, J.F.; Moreau, J.F.; Pellegrin., I.; Fleury, H.; Lafon, M.E.; Masquelier, B.; Trimoulet, P.; Breilh, D.; Titier, K.; Haramburu, F.; Miremont-Salamé, G.; Blaizeau, M.J.; D'Ivernois, C.; Decoin, M.; Delaune, J.; Delveaux, S.; Hanappier, C.; Leleux, O.; Sicard, X.; Uwamaliya-Nziyumvira, B.; Geffard, S.; Leray, J.; Palmer, G.; Touchard, D.; Baker, D.; Bendall, C.; Bloch, M.; Carr, A.; Cooper, D.; Franic, T.; Law, M.; McManus, H.; Petoumenos, K.; Vale, R.; Wright, S.; Edwards, S.; Hoy, J.; Moore, R.; Nicholson, J.; Roth, N.; Watson, K.; Chuah, J.; Ngieng, M.; Nolan, D.; Skett, J.; Cadafalch, J.; Calvo, G.; Codina, C.; Del Cacho, E.; Domingo, P.; Fuster, M.; Gatell, J.; Mateu, S.; Sambeat, M.A.; Sirera, G.; Torres, F.; Vaqué, A.; Clumeck, N.; De Wit, S.; Delforge, M.; Gennotte, A.F.; Gerard, M.; Kabeya, K.; Konopnicki, D.; Libois, A.; Martin, C.; Necsoi, C.; Payen, M.C.; Semaille, P.; Van Laethem, Y.; Bartsch, G.; El-Sadr, W.M.; Krum, E.; Neaton, J.; Thompson, G.; Wentworth, D.; Luskin-Hawk, R.; Telzak, E.; El-Sadr, W.M.; Abrams, D.I.; Cohn, D.; Markowitz, N.; Arduino, R.; Mushatt, D.; Friedland, G.; Perez, G.; Tedaldi, E.; Fisher, E.; Gordin, F.; Crane, L.R.; Sampson, J.; Baxter, J.; Cozzi-Lepri, A.; Fischer, A.H.; Grint, D.; Kirk, O.; Kjaer, J.; Kowalska, J.; Lundgren, J.; Mocroft, A.; Nielsen, J.; Peters, L.; Podlekareva, D.; Reekie, J.; Tverland, J.; Elias, C.; Losso, M.; Vetter, N.; Zangerle, R.; Vetter, N.; Zangerle, R.; Karpov, I.; Vassilenko, A.; Mitsura, V.M.; Suetnov, O.; Clumeck, N.; De Wit, S.; Delforge, M.; Colebunders, R.; Vandekerckhove, L.; Hadziosmanovic, V.; Kostov, K.; Begovac, J.; Jilich, D.; Machala, L.; Sedlacek, D.; Benfield, T.; Kronborg, G.; Larsen, M.; Nielsen, J.; Gerstoft, J.; Hansen, A.-B.E.; Katzenstein, T.; Skinhøj, P.; Pedersen, C.; Ostergaard, L.; Zilmer, K.
2013-01-01
Background: Non-AIDS defining cancers (NADC) are an important cause of morbidity and mortality in HIV-positive individuals. Using data from a large international cohort of HIV-positive individuals, we described the incidence of NADC from 2004-2010, and described subsequent mortality and predictors o
Polanco Martínez, Josue M.; Medina-Elizalde, Martin; Burns, Stephen J.; Jiang, Xiuyang; Shen, Chuan-Chou
2015-04-01
It has been widely accepted by the paleoclimate and archaeology communities that extreme climate events (especially droughts) and past climate change played an important role in the cultural changes that occurred in at least some parts of the Maya Lowlands, from the Pre-Classic (2000 BC to 250 AD) to Post-Classic periods (1000 to 1521 AD) [1, 2]. In particular, a large number of studies suggest that the decline of the Maya civilization in the Terminal Classic Period was greatly influenced by prolonged severe drought events that probably triggered significant societal disruptions [1, 3, 4, 5]. Going further on these issues, the aim of this work is to detect climate regime shifts in several paleoclimate time series from the Yucatán Peninsula (México) that have been used as rainfall proxies [3, 5, 6, 7]. In order to extract information from the paleoclimate data studied, we have used a change point method [8] as implemented in the R package strucchange, as well as the RAMFIT method [9]. The preliminary results show for all the records analysed a prominent regime shift between 400 to 200 BCE (from a noticeable increase to a remarkable fall in precipitation), which is strongest in the recently obtained stalagmite (Itzamna) delta18-O precipitation record [7]. References [1] Gunn, J. D., Matheny, R. T., Folan, W. J., 2002. Climate-change studies in the Maya area. Ancient Mesoamerica, 13(01), 79-84. [2] Yaeger, J., Hodell, D. A., 2008. The collapse of Maya civilization: assessing the interaction of culture, climate, and environment. El Niño, Catastrophism, and Culture Change in Ancient America, 197-251. [3] Hodell, D. A., Curtis, J. H., Brenner, M., 1995. Possible role of climate in the collapse of Classic Maya civilization. Nature, 375(6530), 391-394. [4] Aimers, J., Hodell, D., 2011. Societal collapse: Drought and the Maya. Nature 479(7371), 44-45 (2011). [5] Medina-Elizalde, M., Rohling, E. J., 2012. Collapse of Classic Maya civilization related to modest reduction
Jung, Myung-Hwa; Nikapitiya, Chamilani; Vinay, Tharabenahalli-Nagaraju; Lee, Jehee; Jung, Sung-Ju
2017-09-15
Rock bream iridovirus (RBIV) is a member of the Megalocytivirus genus that causes severe mortality to rock bream. Water temperature is known to affect the immune system and susceptibility of fish to RBIV infection. In this study, we evaluated the time dependent virus replication pattern and time required to completely eliminate virus from the rock bream body against RBIV infection at different water temperature conditions. The rock bream was exposed to the virus and held at 7 (group A1), 4 (group A2) and 2 days (group A3) at 23 °C before the water temperature was reduced to 17 °C. A total of 28% mortality was observed 24-35 days post infection (dpi) in only the 7 day exposure group at 23 °C. In all 23 °C exposure groups, virus replication peaked at 20 to 22 dpi (10(6)-10(7)/μl). In recovery stages (30-100 dpi), the virus copy number was gradually reduced, from 10(6) to 10(1) with faster decreases in the shorter exposure period group at 23 °C. When the water temperature was increased in surviving fish from 17 to 26 °C at 70 dpi, they did not show any mortality or signs of disease and had low virus copy numbers (below 10(2)/μl). Thus, fish need at least 50 days from peaked RBIV levels (approximately 20-25 dpi) to inhibit the virus. This indicates that maintaining the fish at low water temperature (17 °C) for 70 days is sufficient to eradicate RBIV from fish body. Thus, RBIV could be eliminated slowly from the fish body and the virus may be completely eliminated under the threshold of causing mortality. Copyright © 2017 Elsevier Ltd. All rights reserved.
Hacker, Charlotte; Verbeek, Mareike; Schneider, Heike; Steimer, Werner
2014-06-10
Falsely elevated concentrations of immunosuppressants can be caused by reversible adsorption to central venous catheter (CVC) systems. If undetected, this may lead to dose reduction resulting in underdosage which may even entail graft-versus-host disease or organ rejection. We analyzed the adsorption and release for cyclosporine A (CsA) and tacrolimus (Tac) in vitro and in vivo. Four types of CVCs were examined in vitro: two made from polyurethane (PU), one from silicone and one from PU with an incorporated silver ion-based antimicrobial agent. All 26 CVCs analyzed in vitro showed significant reversible adsorption of CsA (n=13; p=0.001) and Tac (n=13; p=0.001, Wilcoxon signed rank test). Immediately after infusing the drugs, the mean concentrations of 6420ng/mL of CsA and 250ng/mL of Tac were measured. Flushing with NaCl lowered the drug release. Besides, blood samples of fifteen patients were taken simultaneously from all lumina of the CVC and via venipuncture. The samples from contaminated lumina showed the mean elevations by a factor of 11 for CsA (n=12) and 89 for Tac (n=3). Blood sampling for immunosuppressant monitoring should thus never be performed from lumina previously used for infusing the drug even after prolonged periods of time and extensive rinsing. Copyright © 2014 Elsevier B.V. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Wang Fengyan [College of Science, Jimei University, Xiamen Fujian 361021 (China)]. E-mail: wangfy68@163.com; Zeng Guangzhao [Department of Mathematics, ShaoGuan University, ShaoGuan, GuangDong 512005 (China)]. E-mail: guangzhaoz@sgu.edu.cn
2007-05-15
In this paper, we introduce and study a Lotka-Volterra predator-prey system with impulsive ratio-harvesting the prey and time delays. By using Floquet theory and small amplitude perturbation skills, we discuss the boundary periodic solutions for predator-prey system under periodic pulsed conditions. The stability analysis of the boundary periodic solution yields an invasion threshold of the predator. Further, by use of the coincidence degree theorem and its related continuous theorem we prove the existence of the positive periodic solutions of the system when the value of the coefficient is large than the threshold. Finally, by comparing bifurcation diagrams with different bifurcation parameters, we show that the impulsive effect and the time delays bring to the system to be more complex, which experiences a complex process of cycles {sup {yields}} quasi-periodic oscillation {sup {yields}} periodic doubling cascade {sup {yields}} chaos.
Energy Technology Data Exchange (ETDEWEB)
Rogers, J.; Porter, K.
2012-03-01
This paper updates previous work that describes time period-based and other approximation methods for estimating the capacity value of wind power and extends it to include solar power. The paper summarizes various methods presented in utility integrated resource plans, regional transmission organization methodologies, regional stakeholder initiatives, regulatory proceedings, and academic and industry studies. Time period-based approximation methods typically measure the contribution of a wind or solar plant at the time of system peak - sometimes over a period of months or the average of multiple years.
Directory of Open Access Journals (Sweden)
Liu Zhenjie
2009-01-01
Full Text Available This paper investigates the existence of periodic solutions of a ratio-dependent predator-prey diffusion system with Michaelis-Menten functional responses and time delays in a two-patch environment on time scales. By using a continuation theorem based on coincidence degree theory, we obtain suffcient criteria for the existence of periodic solutions for the system. Moreover, when the time scale is chosen as or , the existence of the periodic solutions of the corresponding continuous and discrete models follows. Therefore, the methods are unified to provide the existence of the desired solutions for the continuous differential equations and discrete difference equations.
Institute of Scientific and Technical Information of China (English)
Desheng TIAN
2008-01-01
The author considers a three-species ratio-dependent predator-prey model with time delay in a two-patch environments. This model is of periodic coefficients, which incorporates the periodicity of the environment. By means of the coincidence degree theory, sufficient conditions for the existence of at least one positive periodic solution of this model are established. Moreover, The author shows that the system is uniformly persistent under the conditions.
Institute of Scientific and Technical Information of China (English)
Xiaoyuan CHU; Yujie WANG; Yiping XIA; Yun WU; Lin CHEN
2009-01-01
In order to provide a basis for water conservation in the restoration of vegetation for an urban water resource area, we studied the generation of runoff characteristics in four typical forests over three time periods in Jinyun Mountain, Chongqing City, based on the observation data of rainfall and runoff processes during the period 2002-2005. The results show that: 1) Rainfall was distributed evenly during the years 2002-2005. Annual rainfall variability was 4.46% and coefficient of variation was 0.0618. Average monthly rainfall tended towards a normal distribution N (113.8, 45972). 2) Both precipitation and runoff can be clearly divided into a dry and a wet season. The dry season was from October to March and the wet season from April to September. Most of annual runoff of the four forest stands occurred in the wet season. The surface runoff in the wet season accounted for more than 85% of the annual runoff, and more than 75% of underground runoff. 3) Both peak values of surface runoff and underground runoff occurred in June. The relation between monthly rainfall and surface/underground runoff was fitted by the model W = aP2 + bP + c. The order of annual surface runoff was as follows: Phyllostachys pub-escens forest > shrub forest > mixed Pinus massoniana-broadleaf forest > evergreen broad-leaved forest. The annual underground runoff was evergreen broad-leaved forest > mixed Pinus massoniana-broadleaf forest >Phyl-lostachys pubescens forest > shrub forest. 4) Under similar rainstorms events, the order of the surface runoff coefficient was: evergreen broad-leaved forest mixed Pinus massoniana-broadleaf forest > Phyllostachys pubescens forest > shrub forest. The relation between rainstorms and surface runoff was fitted by the linear relationship: Q = mp-n. Both mixed Pinus massoniana-broadleaf forest and evergreen broad-leaved forest have better flood regulation effects on an annual and monthly basis and per individual rainstorm. The function of Phyllostachys
Directory of Open Access Journals (Sweden)
A. Fujiwara
2015-08-01
Full Text Available Timing of sea ice retreat (TSR as well as cell size of primary producers (i.e., phytoplankton plays crucial roles in seasonally ice-covered marine ecosystem. Thus, it is important to monitor the temporal and spatial distribution of phytoplankton community size structure. Prior to this study, an ocean color algorithm has been developed to derive phytoplankton size index FL, which is defined as the ratio of chlorophyll a derived from the cells larger than 5 μm to the total chl a using satellite remote sensing for the Chukchi and Bering shelves. Using this method, we analyzed pixel-by-pixel relationships between FL during marginal ice zone (MIZ bloom period and TSR over a period of 1998–2013. The influence of TSR on sea surface temperature (SST and changes in ocean heat content (ΔOHC during the MIZ bloom period were also investigated. A significant negative relationship between FL and TSR was widely found in the shelf region during MIZ bloom season. On the other hand, we found a significant positive (negative relationship between SST (ΔOHC and TSR. That is, earlier sea-ice retreat was associated with a dominance of larger phytoplankton during a colder and weakly stratified MIZ bloom season, suggesting that duration of nitrate supply, which is important for large-sized phytoplankton growth in this region (i.e., diatoms, can change according to TSR. In addition, under-ice phytoplankton blooms are likely to occur in years with late ice retreat, because sufficient light for phytoplankton growth can pass through the ice and penetrate into the water columns due to an increase in solar radiation toward the summer solstice. Moreover, we found not only the length of ice-free season but also annual median of FL positively correlated with annual net primary production (APP. Thus, both phytoplankton community composition and growing season are important for APP in the study area. Our findings showed quantitative relationship between the inter
Rogan, Paul J.
This research attempted to identify differences, or lack of them, in time orientation of Caucasian, Black and Chicano young male first offenders at various periods of imprisonment; beginning, middle, and end. The instrument that was chosen to measure time orientation was a combination of two questionnaires--the Time Competence scale of the…
Nagesh, Deepthi; Ghosh, Shayani
2017-02-11
Forensic Science is the application of science to the criminal and civil laws that are enforced by police agencies in a criminal justice system. It is a science which relies on physical evidence; one of the important physical evidences being blood. The purpose of this research was to determine the efficacy of luminol reagent in detecting bloodstains on different surfaces, concealed by multiple layers of paint, over a period of time and also to compare the intensities of chemiluminescence exhibited by them. In this study, dry wall, wooden planks and metal surfaces were identified as commonly encountered surfaces at crime scenes and hence 25 of each surface were simulated and blood was spattered, which were then concealed by progressive layers of paint specific to each surface. Thereafter, each surface was critically observed for the intensity of chemiluminescence, following the application of luminol and the results were documented as photographs. The research was conducted for duration of 50 days, in order to study the effect of ageing of concealment upon detection of bloodstains using luminol. Varying intensities of chemiluminescence were displayed by all the three simulated surfaces deposited with paint over bloodstains up to three layers of concealment, depending on the nature of the surface which were captured using photography. The highest intensity of chemiluminescence was shown by concealed bloodstains on dry wall and metal surfaces, despite the number of layers of concealment. However, an increase in the number of layers of concealment produced a significant decrease in the intensity of chemiluminescenece displayed by the bloodstains concealed by paint upon reacting with luminol on metal sheets, which was not found to be uniform and consistent on the other surfaces. These findings highlight the fact that bloodstains concealed by paint could be effectively detected by luminol reagent, despite the nature and ageing of concealment and thereby provide a lead to
Haff, G Gregory; Jackson, Janna R; Kawamori, Naoki; Carlock, Jon M; Hartman, Michael J; Kilgore, J Lon; Morris, Robert T; Ramsey, Michael W; Sands, William A; Stone, Michael H
2008-03-01
The purpose of this investigation was to study the effects of an 11-week training period performed by female weightlifters. Two weeks before this investigation, baseline measures for total testosterone, cortisol, and testosterone:cortisol ratio were collected. The 11-week training program consisted of the core exercises (i.e., clean, clean and jerk, and snatch) and other supplemental exercises (i.e., clean pull, snatch pull, squat, and front squat). Hormonal, isometric, and dynamic middle thigh pull force-time curve characteristics were assessed biweekly throughout the duration of the investigation, whereas volume load and training intensity were assessed weekly throughout the investigation. The testosterone:cortisol ratio of the baseline (1.19 +/- 0.64) was significantly different from the ratio of weeks 1 (0.67 +/- 0.36) and 9 (0.94 +/- 0.66). When the week-to-week values were compared, week 1 (0.67 +/- 0.36) was significantly different (P < 0.05; eta = 0.84) from week 3 (1.06 +/- 0.54). A very strong correlation (r = -0.83; r = 0.69) was found between the percentage change of the testosterone:cortisol ratio and volume load from weeks 1 to 11. Moderate to very strong correlations were noted between the percentage change in volume load and isometric peak force, peak force during the 30% isometric peak force trial, and peak force during the 100-kg trial during the 11 weeks of training. The primary finding of this study was that alterations in training volume load can result in concomitant changes in the anabolic-to-catabolic balance, as indicated by the testosterone:cortisol ratio, and the ability to generate maximal forces.
2011-01-01
Background Trafficking in women is a widespread human rights violation commonly associated with poor mental health. Yet, to date, no studies have used psychiatric diagnostic assessment to identify common forms of mental distress among survivors returning to their home country. Methods A longitudinal study was conducted of women aged 18 and over who returned to Moldova between December 2007 and December 2008 registered by the International Organisation for Migration as a survivor of human trafficking. Psychiatric diagnoses in women at a mean of 6 months after return (range 2-12 months) were made by a trained Moldavian psychiatrist using the Structured Clinical Interview for DSM-IV, and compared with diagnoses recorded in the same women within 5 days of return. We described the socio-demographic characteristics of the women in the sample including both pre and post-trafficking information. We then described the distribution of mental health diagnoses recorded during the crisis intervention phase (1-5 days after return) and the re-integration phase (2-12 months after return). We compared diagnoses at the patient level between the two time points by tabulating the diagnoses and carrying out a kappa test of agreement and the Stuart-Maxwell test for marginal homogeneity (an extension of the McNemar test to kxk table). Results 120/176 (68%) eligible women participated. At 2-12 months after their return, 54% met criteria for at least one psychiatric diagnoses comprising post-traumatic stress disorder (PTSD) alone (16%); co-morbid PTSD (20%); other anxiety or mood disorder (18%). 85% of women who had been diagnosed in the crisis phase with co-morbid PTSD or with another anxiety or mood disorder sustained a diagnosis of any psychiatric disorder when followed up during rehabilitation. Conclusions Trafficked women returning to their country of origin are likely to suffer serious psychological distress that may endure well beyond the time they return. Women found to have co
Directory of Open Access Journals (Sweden)
Gorceag Lilia T
2011-04-01
Full Text Available Abstract Background Trafficking in women is a widespread human rights violation commonly associated with poor mental health. Yet, to date, no studies have used psychiatric diagnostic assessment to identify common forms of mental distress among survivors returning to their home country. Methods A longitudinal study was conducted of women aged 18 and over who returned to Moldova between December 2007 and December 2008 registered by the International Organisation for Migration as a survivor of human trafficking. Psychiatric diagnoses in women at a mean of 6 months after return (range 2-12 months were made by a trained Moldavian psychiatrist using the Structured Clinical Interview for DSM-IV, and compared with diagnoses recorded in the same women within 5 days of return. We described the socio-demographic characteristics of the women in the sample including both pre and post-trafficking information. We then described the distribution of mental health diagnoses recorded during the crisis intervention phase (1-5 days after return and the re-integration phase (2-12 months after return. We compared diagnoses at the patient level between the two time points by tabulating the diagnoses and carrying out a kappa test of agreement and the Stuart-Maxwell test for marginal homogeneity (an extension of the McNemar test to kxk table. Results 120/176 (68% eligible women participated. At 2-12 months after their return, 54% met criteria for at least one psychiatric diagnoses comprising post-traumatic stress disorder (PTSD alone (16%; co-morbid PTSD (20%; other anxiety or mood disorder (18%. 85% of women who had been diagnosed in the crisis phase with co-morbid PTSD or with another anxiety or mood disorder sustained a diagnosis of any psychiatric disorder when followed up during rehabilitation. Conclusions Trafficked women returning to their country of origin are likely to suffer serious psychological distress that may endure well beyond the time they return. Women
Ostrovschi, Nicolae V; Prince, Martin J; Zimmerman, Cathy; Hotineanu, Mihai A; Gorceag, Lilia T; Gorceag, Viorel I; Flach, Clare; Abas, Melanie A
2011-04-14
Trafficking in women is a widespread human rights violation commonly associated with poor mental health. Yet, to date, no studies have used psychiatric diagnostic assessment to identify common forms of mental distress among survivors returning to their home country. A longitudinal study was conducted of women aged 18 and over who returned to Moldova between December 2007 and December 2008 registered by the International Organisation for Migration as a survivor of human trafficking. Psychiatric diagnoses in women at a mean of 6 months after return (range 2-12 months) were made by a trained Moldavian psychiatrist using the Structured Clinical Interview for DSM-IV, and compared with diagnoses recorded in the same women within 5 days of return. We described the socio-demographic characteristics of the women in the sample including both pre and post-trafficking information. We then described the distribution of mental health diagnoses recorded during the crisis intervention phase (1-5 days after return) and the re-integration phase (2-12 months after return). We compared diagnoses at the patient level between the two time points by tabulating the diagnoses and carrying out a kappa test of agreement and the Stuart-Maxwell test for marginal homogeneity (an extension of the McNemar test to kxk table). 120/176 (68%) eligible women participated. At 2-12 months after their return, 54% met criteria for at least one psychiatric diagnoses comprising post-traumatic stress disorder (PTSD) alone (16%); co-morbid PTSD (20%); other anxiety or mood disorder (18%). 85% of women who had been diagnosed in the crisis phase with co-morbid PTSD or with another anxiety or mood disorder sustained a diagnosis of any psychiatric disorder when followed up during rehabilitation. Trafficked women returning to their country of origin are likely to suffer serious psychological distress that may endure well beyond the time they return. Women found to have co-morbid PTSD or other forms of anxiety and
Rakkiyappan, R; Sivaranjani, R; Velmurugan, G; Cao, Jinde
2016-05-01
In this paper, the problem of the global O(t(-α)) stability and global asymptotic periodicity for a class of fractional-order complex-valued neural networks (FCVNNs) with time varying delays is investigated. By constructing suitable Lyapunov functionals and a Leibniz rule for fractional differentiation, some new sufficient conditions are established to ensure that the addressed FCVNNs are globally O(t(-α)) stable. Moreover, some sufficient conditions for the global asymptotic periodicity of the addressed FCVNNs with time varying delays are derived, showing that all solutions converge to the same periodic function. Finally, numerical examples are given to demonstrate the effectiveness and usefulness of our theoretical results.
Energy Technology Data Exchange (ETDEWEB)
Zhang Long [College of Mathematics and System Sciences, Xinjiang University, Urumqi 830046 (China)], E-mail: longzhang_xj@sohu.com; Teng Zhidong [College of Mathematics and System Sciences, Xinjiang University, Urumqi 830046 (China)], E-mail: zhidong@xju.edu.cn
2008-12-15
In this paper, we study two species predator-prey Lotka-Volterra type dispersal system with periodic coefficients in two patches, in which both the prey and predator species can disperse between two patches. By utilizing analytic method, sufficient and realistic conditions on permanence and the existence of periodic solution are established. The theoretical results are confirmed by a special example and numerical simulations.
Yoneda, Akihiro; Nishikawa, Masanori; Uehara, Shuichiro; Oue, Takaharu; Usui, Noriaki; Inoue, Masami; Fukuzawa, Masahiro; Okuyama, Hiroomi
2016-03-01
To date, no detailed study of the changes in the image-defined risk factors (IDRFs) after neoadjuvant chemotherapy has been performed. The aim of this study was to investigate the effect of chemotherapy on IDRFs for stage L2 neuroblastomas. Fifteen stage L2 patients treated by neoadjuvant chemotherapy were selected. Changes after chemotherapy in the number of positive IDRFs, tumor size and major surgical complications were evaluated. All IDRFs disappeared after chemotherapy in four patients (group A) and a reduction in the number of IDRFs, but not disappearance, after chemotherapy was observed in five patients (group B). No change in the number of IDRFs after chemotherapy was observed in six patients (group C). All tumors in groups A shrunk to negative for IDRFs after chemotherapy. For negative IDRFs, tumors should shrink to chemotherapy.
Control over few-photon pulses by a time-periodic modulation of the photon emitter coupling
Pletyukhov, Mikhail; Pedersen, Kim G. L.; Gritsev, Vladimir
2017-04-01
We develop a Floquet scattering formalism for the description of quasistationary states of microwave photons in a one-dimensional waveguide interacting with a nonlinear cavity by means of a periodically modulated coupling. This model is inspired by the recent progress in engineering of tunable coupling schemes with superconducting qubits. We argue that our model can realize the quantum analog of an optical chopper. We find strong periodic modulations of the transmission and reflection envelopes in the scattered few-photon pulses, including photon compression and blockade, as well as dramatic changes in statistics. Our theoretical analysis allows us to explain these nontrivial phenomena as arising from nonadiabatic memory effects.
Directory of Open Access Journals (Sweden)
Van Greuningen Malou
2012-12-01
Full Text Available Abstract Background The high cost of training and the relatively long period of training for physicians make it beneficial to stimulate physicians to retire later. Therefore, a better understanding of the link between the factors influencing the decision to retire and actual turnover would benefit policies designed to encourage later retirement. This study focuses on actual GP turnover and the determining factors for this in the Netherlands. The period 2003–2007 saw fewer GPs retiring from general practice than the period 1998–2002. In addition, GPs’ retirement age was higher in 2003–2007. For these two periods, we analysed work perception, objective workload and reasons for leaving, and related these with the probability that GPs would leave general practice at an early age. Methods In 2003, a first retrospective survey was sent to 520 self-employed GPs who had retired between 1998 and 2002. In 2008, the same survey was sent to 405 GPs who had retired between 2003 and 2007. The response rates were 60% and 54%, respectively. Analyses were done to compare work perception, objective workload, external factors and personal reasons for retiring. Results For both male and female GPs, work perception was different in the periods under scrutiny: both groups reported greater job satisfaction and a lower degree of emotional exhaustion in the later period, although there was no notable difference in subjective workload. The objective workload was lower in the second period. Moreover, most external factors and personal reasons that may contribute to the decision to retire were reported as less important in the second period. There was a stronger decrease in the probability that female GPs leave general practice within one year than for male GPs. This underscores the gender differences and the need for disaggregated data collection. Conclusions The results of this study suggest that the decrease in the probability of GPs leaving general practice
DEFF Research Database (Denmark)
Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen
2007-01-01
A 0.8 ps flat top pulse is generated using a long-period fibre grating and used as control pulse for the first time in a 320 Gb/s demultiplexer. The effect is an increased error-free timing tolerance...
Helm, M; Hossfeld, B; Schlechtriemen, T; Braun, J; Lampl, L; Bernhard, M
2011-12-01
Intraosseous infusion has become established as a fast and safe alternative to conventional vascular access in emergency situations. Originally the use of intraosseous access was limited to children up to 6 years of age and to adults for cardiopulmonary resuscitation but this limitation has now been removed. The aim of this study was to obtain data on mission reality regarding the use of intraosseous access in the prehospital setting against the background of the expanded recommendations on the use of the intraosseous infusion. An analysis of rescue missions by all rescue helicopters of the ADAC (German Automobile Club) Air Rescue as well as the German Air Rescue Service (58 helicopter emergency medical service bases) over a 4 year period from January 2005 to December 2008 was carried out. A total of 247,454 rescue missions were carried out during the study period and in 525 patients (0.2% of the total study collective) an intraosseous access was established. There was a significant increase in the intraosseous infusion rate from 0.1% to 0.4% (premarkable increase of intraosseous infusions in trauma patients in the last year of the study period compared to the previous years (38% in 2008 vs. 27-30% in 2005-2007). Furthermore, there was an increase in the number of different drug groups used for intraosseous infusion over the study period. The expanded indication recommendations for the use of intraosseous infusion in the prehospital setting enter more and more mission reality in air rescue services in Germany.
Gerez, Sabih H.; Heemstra de Groot, S.M.; Herrmann, O.E.
1992-01-01
Rate-optimal scheduling of iterative data-flow graphs requires the computation of the iteration period bound. According to the formal definition, the total computational delay in each directed loop in the graph has to be calculated in order to determine that bound. As the number of loops cannot be
Neijts, Roel; Amin, Shilu; van Rooijen, Carina; Deschamps, Jacqueline
2017-02-15
Cdx and Hox transcription factors are important regulators of axial patterning and are required for tissue generation along the vertebrate body axis. Cdx genes have been demonstrated to act upstream of Hox genes in midgestation embryos. Here, we investigate the role of Cdx transcription factors in the gradual colinear activation of the Hox clusters. We found that Hox temporally colinear expression is severely affected in epiblast stem cells derived from Cdx null embryos. We demonstrate that after initiation of 3' Hox gene transcription, Cdx activity is crucial for H3K27ac deposition and for accessibility of cis-regulatory elements around the central - or 'trunk' - Hox genes. We thereby identify a Cdx-responsive segment of HoxA, immediately 5' to the recently defined regulatory domain orchestrating initial transcription of the first Hox gene. We propose that this partition of HoxA into a Wnt-driven 3' part and the newly found Cdx-dependent middle segment of the cluster, forms a structural fundament of Hox colinearity of expression. Subsequently to initial Wnt-induced activation of 3' Hox genes, Cdx transcription factors would act as crucial effectors for activating central Hox genes, until the last gene of the cluster arrests the process. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
DEFF Research Database (Denmark)
Skaaby, Tea; Husemoen, Lise Lotte Nystrup; Thuesen, Betina Heinsbæk
2015-01-01
of 20048 persons participated in the seven studies. We used logistic regression to analyse the associations between possible determinants and atopy defined as serum specific IgE or skin prick test positivity against inhalant allergens. Associations were expressed as odds ratios (ORs) with 95% confidence......, physical activity or body mass except in women only, where we found a positive association (OR for obese vs. normal weight: 1.18; 95% CI: 1.00, 1.39) with ptrend = 0.032. CONCLUSIONS: Of interest for preventive purposes, we found that atopy was associated with some of the reversible lifestyle...
Directory of Open Access Journals (Sweden)
Michael P Anastario
Full Text Available Following the declaration that President Mwai Kibaki was the winner of the Kenyan presidential election held on December 27, 2007, a period of post-election violence (PEV took place. In this study, we aimed to identify whether the period of PEV in Kenya was associated with systematic changes in sexual assault case characteristics.Medical records of 1,615 patients diagnosed with sexual assault between 2007 and 2011 at healthcare facilities in Eldoret (n = 569, Naivasha (n = 534, and Nakuru (n = 512 were retrospectively reviewed to examine characteristics of sexual assault cases over time. Time series and linear regression were used to examine temporal variation in case characteristics relative to the period of post-election violence in Kenya. Key informant interviews with healthcare workers at the sites were employed to triangulate findings. The time series of sexual assault case characteristics at these facilities were examined, with a specific focus on the December 2007-February 2008 period of post-election violence. Prais-Winsten estimates indicated that the three-month period of post-election violence was associated with a 22 percentage-point increase in cases where survivors did not know the perpetrator, a 20 percentage-point increase in cases with more than one perpetrator, and a 4 percentage-point increase in cases that had evidence of abdominal injury. The post-election violence period was also associated with an 18 percentage-point increase in survivors waiting >1 month to report to a healthcare facility. Sensitivity analyses confirmed that these characteristics were specific to the post-election violence time period.These results demonstrate systematic patterns in sexual assault characteristics during the PEV period in Kenya.
2010-07-01
... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false Does the 2-year time period in Â§ 302-2.8 include time that I cannot travel and/or transport my household effects due to... time that I cannot travel and/or transport my household effects due to shipping restrictions to or from...
Wang, Xiao Yu; Guo, Yuming; FitzGerald, Gerry; Aitken, Peter; Tippett, Vivienne; Chen, Dong; Wang, Xiaoming; Tong, Shilu
2015-01-01
Different locations and study periods were used in the assessment of the relationships between heatwaves and mortality. However, little is known about the comparability and consistency of the previous effect estimates in the literature. This study assessed the heatwave-mortality relationship using different study periods in the three largest Australian cities (Brisbane, Melbourne and Sydney). Daily data on climatic variables and mortality for the three cities were obtained from relevant government agencies between 1988 and 2011. A consistent definition of heatwaves was used for these cities. Poisson generalised additive model was fitted to assess the impact of heatwaves on mortality. Non-accidental and circulatory mortality significantly increased during heatwaves across the three cities even with different heatwave definitions and study periods. Using the summer data resulted in the largest increase in effect estimates compared to those using the warm season or the whole year data. The findings may have implications for developing standard approaches to evaluating the heatwave-mortality relationship and advancing heat health warning systems. It also provides an impetus to methodological advance for assessing climate change-related health consequences.
Directory of Open Access Journals (Sweden)
Xiao Yu Wang
Full Text Available Different locations and study periods were used in the assessment of the relationships between heatwaves and mortality. However, little is known about the comparability and consistency of the previous effect estimates in the literature. This study assessed the heatwave-mortality relationship using different study periods in the three largest Australian cities (Brisbane, Melbourne and Sydney.Daily data on climatic variables and mortality for the three cities were obtained from relevant government agencies between 1988 and 2011. A consistent definition of heatwaves was used for these cities. Poisson generalised additive model was fitted to assess the impact of heatwaves on mortality.Non-accidental and circulatory mortality significantly increased during heatwaves across the three cities even with different heatwave definitions and study periods. Using the summer data resulted in the largest increase in effect estimates compared to those using the warm season or the whole year data.The findings may have implications for developing standard approaches to evaluating the heatwave-mortality relationship and advancing heat health warning systems. It also provides an impetus to methodological advance for assessing climate change-related health consequences.
Directory of Open Access Journals (Sweden)
Zhenjie Liu
2009-01-01
Full Text Available This paper investigates the existence of periodic solutions of a ratio-dependent predator-prey diffusion system with Michaelis-Menten functional responses and time delays in a two-patch environment on time scales. By using a continuation theorem based on coincidence degree theory, we obtain suffcient criteria for the existence of periodic solutions for the system. Moreover, when the time scale 𝕋 is chosen as ℝ or ℤ, the existence of the periodic solutions of the corresponding continuous and discrete models follows. Therefore, the methods are unified to provide the existence of the desired solutions for the continuous differential equations and discrete difference equations.
Ratnaningrum, Diah; Endah, Een Sri; Pudjiraharti, Sri
2017-01-01
Research on extraction method of emprit ginger using ethanol with agitation of 100 rpm at different temperatures (ambient temperature, 40, and 50°C) and various extraction period of times (30, 60, and 90 minutes) was conducted. Analysis of chemicals content i.e. total phenolic and total flavonoid. The objective of this work was to study the effect of temperatures and extraction period of times on the chemicals content of its ethanol extract. Based on the results of the test, the highest content total flavonoid (5.17% w/w) was resulted at 40°C for 90 minutes, while the total phenolic content was not affected by either temperature or extraction period of times used. The content of total phenolic was around 2.39% to 2.65% w/w.
Institute of Scientific and Technical Information of China (English)
无
2014-01-01
Soil salinity is one of the most severe abiotic stress factors threatening agriculture worldwide. Hence,particular interest exists in unraveling mechanisms leading to salt tolerance and improved crop plant performance onsaline soils. Barley is considered to be one of the most salinity-tolerant crops, but varying levels of tolerance are wellcharacterized. A proteomic analysis of the roots of two contrasting cultivars （cv. Steptoe and cv. Morex） is presented.Young plants were exposed to a period of 1, 4, 7, or 10 d at 0, 100, or 150mM NaCI. The root proteome was analyzedbased on two-dimensional gel electrophoresis. A number of cultivar-specific and salinity stress-responsive proteins wereidentified. Mass spectrometry-based identification was successful for 74 proteins, and a hierarchical clustering analysisgrouped these into five clusters based on similarity of expression profile. The rank product method was applied to sta-tistically access the early and late responses, and this delivered a number of new candidate proteins underlying salinitytolerance in barley. Among these were some germin-like proteins, some pathogenesis-related proteins, and numerousas-yet uncharacterized proteins. Notably, proteins involved in detoxification pathways and terpenoid biosynthesis weredetected as early responsive to salinity and may function as a means of modulating growth-regulating mechanisms andmembrane stability via fine tuning of phytohormone and secondary metabolism in the root.
The Detection of Hidden Periodicities in EEG
Institute of Scientific and Technical Information of China (English)
YOU Rong-yi
2007-01-01
Abstract.A novel method for detecting the hidden periodicities in EEG is proposed.By using a width-varying window in the time domain, the structure function of EEG time series is defined. It is found that the minima of the structure function, within a finite window width, can be found regularly, which indicate that there are some certain periodicities associated with EEG time series. Based on the structure function, a further quadratic structure function of EEG time series is defined. By quadratic structure function, it can be seen that the periodicities of EEG become more obvious, moreover, the period of EEG can be determined accurately. These results will be meaningful for studying the neuron activity inside the human brain.
Oscillations following periodic reinforcement.
Monteiro, Tiago; Machado, Armando
2009-06-01
Three experiments examined behavior in extinction following periodic reinforcement. During the first phase of Experiment 1, four groups of pigeons were exposed to fixed interval (FI 16s or FI 48s) or variable interval (VI 16s or VI 48s) reinforcement schedules. Next, during the second phase, each session started with reinforcement trials and ended with an extinction segment. Experiment 2 was similar except that the extinction segment was considerably longer. Experiment 3 replaced the FI schedules with a peak procedure, with FI trials interspersed with non-food peak interval (PI) trials that were four times longer. One group of pigeons was exposed to FI 20s PI 80s trials, and another to FI 40s PI 160s trials. Results showed that, during the extinction segment, most pigeons trained with FI schedules, but not with VI schedules, displayed pause-peck oscillations with a period close to, but slightly greater than the FI parameter. These oscillations did not start immediately after the onset of extinction. Comparing the oscillations from Experiments 1 and 2 suggested that the alternation of reconditioning and re-extinction increases the reliability and earlier onset of the oscillations. In Experiment 3 the pigeons exhibited well-defined pause-peck cycles since the onset of extinction. These cycles had periods close to twice the value of the FI and lasted for long intervals of time. We discuss some hypotheses concerning the processes underlying behavioral oscillations following periodic reinforcement.
Sutter, E. M.; Ingham, M.
2016-12-01
Saline intrusion research using geoelectrical time-lapse monitoring, is often directed towards imaging the saltwater-freshwater boundary and the amount of seawater mixing within a coastal aquifer. However, these time series can contain additional information about subsurface hydrologic properties like hydraulic conductivity and permeability which are crucial elements in coastal groundwater management. In this study, DC resistivity time series from tidal time-lapse monitoring surveys of a shallow coastal sand and gravel aquifer in New Zealand have been analysed for recurring patterns of percentage seawater mixing in different portions of the aquifer. The results show a distinctly different behaviour of percentage seawater change with time for several horizontal locations along two profile lines with varying depth. In addition, the geoelectric time series have been cross-correlated with tidal stage data approximated near the survey location in order to find portions of the aquifer that exhibit different time lags with respect to a diurnal tidal cycle. First results yield a remarkably similar picture to resistivity ratios obtained between high and low tide inversion models of the DC resistivity time series both at different locations and for different seasons. The two methods indicate a correlation between rising and falling tides and the resistivity changes observed from geoelectrical monitoring studies .This may be used to distinguish between more or less hydraulically conductive portions of a coastal aquifer.
Allen, Richard P; Dean, Terry; Earley, Christopher J
2005-09-01
The diagnostic criteria for restless legs syndrome (RLS) indicate that both time-of-day and rest effects induce or aggravate symptoms. Periodic limb movements while awake (PLMW) provide an objective motor sign of RLS that can be measured during an awake suggested immobilization test (SIT). This study uses the SIT at different times of the day and analyzes time-of-day and duration-of-rest effects and their interaction on the PLMW. Twenty-eight RLS patients who were not on medications had SIT tests at 10 pm, 8 am and 4 pm on two consecutive days. PLMW for each 20-min period were analyzed for time-of-day and rest effects and their interaction. PLMW increase from the first to last 20-min SIT period assessed the rest-effects. Significant effects were found for rest, time-of-day and rest-time-of-day interaction. The rest-effect increased most from morning to afternoon while total PLMW increased more from afternoon to night. Males compared to females had significantly more PLMW and a larger rest-effect change with time-of-day. Rest and time-of-day effects and their interaction all increase RLS symptoms. PLMW increase with rest may provide a sensitive measure of symptom severity.
Schiantarelli, P; Toson, G; Guelfi, M; Murmann, W
1978-01-01
A study on variables influencing the gastric secretory response of pylorus-ligated Wistar rat, shows that: 1. 24 h is a sufficient fasting period for satisfactory emptying of the stomach, periods of up to 48 h yielding no advantage; 2. between 2 and 4 h is the most appropriate pyloric ligation time because in this range there are no variations in volume of gastric secretion, concentration and output of acid per unit of ligation time; 3. sex has no influence on any of the parameters; 4. animals should be age-selected because only above a given age threshold the gastric secretory response per unit of bodyweight is constant.
Liu, Huiyu; Xu, Xiaojuan; Lin, Zhenshan; Zhang, Mingyang; Mi, Ying; Huang, Changchun; Yang, Hao
2016-12-01
With the ensemble Empirical Mode Decomposition Method (EEMD) and the non-parametric Mann-Kendall Test, the quasi-periodic and abrupt changes of sedimentation rate at multiple time scales, and their relations to climate changes and human activities from 1951 to 2010 in Meiliang Bay of Lake Taihu (China) were studied. The results showed the following. (1) The change in sedimentation rate can be completely decomposed into three quasi-periodic changes on 3.7, 6.4, and 24-yr time scales, and a long-term trend. (2) The quasi-periodic changes in sedimentation rate are significantly and positively related to changes in annual average temperature at 6.4 and 24-yr time scales and human activities at 3.7-yr time scales, and not significantly related to precipitation at these time scales. The trend of sedimentation rate has a negative relation with temperature, but positive relations with precipitation and human activities. As a whole, the total variance contribution of climate changes to the quasi-periodic changes of sedimentation rate is close to that of human activities; (3) Temperature and precipitation are possibly related to the abrupt change of sedimentation rate as a whole. Floods have significant impacts on abrupt changes in the sedimentation rate at 3.7, 6.4 and 24-yr time scales. Moreover, some abrupt changes of sedimentation rate at 3.7- and 6.4-yr time scales are partly related to the changes of precipitation at 3.1-yr time scale and temperature at 5-yr time scale. The results of this study will help identify the impacts of climate change and human activities on lake sedimentation at different time scales, and will be available for use as a guide for reasonable development and effective protection of lake resources.
Directory of Open Access Journals (Sweden)
V. M. Zhenilo
2007-01-01
Full Text Available Objective: to study the level of peroxides and the activity of superoxide dismutase (SOD in females with gestosis in the perioperative period.Materials and methods: 85 females in whom delivery had been performed under spinal anesthesia using conventional perioperative intensive care were examined. A control group comprised 30 females with uncomplicated pregnancy; Group 1 included 26 females with moderate gestosis; Group 2 consisted of 29 females with severe gestosis. The severity of gestosis was determined by means of the Goecke scale that had been modified by G. M. Savelyeva. The groups of the examinees were matched by height, weight, age, and gender.Results: there is intensification of free radical processes and a standard adaptive response of the antioxidative system forms in the pregnant females exposed to surgical delivery under spinal anesthesia. In dynamics, this reaction is characterized by a certain pattern: the maximum activation on the first postoperative day, some depletion on day 3, and recovery of compensatory capacities on day 5. The antioxidative system of the females with uncomplicated pregnancy generally shows a balanced response to activated free radical processes during surgical delivery and in the postoperative period. There is stress in moderate gestosis-complicated pregnancy and depletion of the antiox-idative system in severely progressive gestosis, which diminishes the body’s adaptive capacities and leads to the formation of chronic oxidative stress as a leading factor of the pathogenesis of the disease. Imbalance between free radical oxidation processes and the antioxidative system increases when surgical delivery is performed. In the females with moderate gestosis, oxidative stress may be characterized as subcompensated with a moderate increase in the concentration of peroxides in the intra- and postoperative period, as compared with those with physiological pregnancy.Conclusion. Severe gestosis is characterized by a
Nitsche, Ludwig C.; Nitsche, Johannes M.; Brenner, Howard
1988-01-01
The sedimentation and diffusion of a nonneutrally buoyant Brownian particle in vertical fluid-filled cylinder of finite length which is instantaneously inverted at regular intervals are investigated analytically. A one-dimensional convective-diffusive equation is derived to describe the temporal and spatial evolution of the probability density; a periodicity condition is formulated; the applicability of Fredholm theory is established; and the parameter-space regions are determined within which the existence and uniqueness of solutions are guaranteed. Numerical results for sample problems are presented graphically and briefly characterized.
Energy Technology Data Exchange (ETDEWEB)
Tveit, T.M.; Fogelholm, C.J. (Helsinki Univ. of Technology, Dept. of Energy Technology, P.O.Box 4400, FI-02015 TKK (Finland)); Sangsu, K. (Korea District Heating Corp., R and D Dept., 186 Bundang-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-908 (Korea))
2008-09-15
In this paper a multi-period MINLP model for optimising operation and structural changes to CHP plants in district heating networks with long-term thermal storage is applied to an existing district heating network. The best result found shows an annual profit of approximately 22.9 million USD. The best solution found without the thermal storage shows an annual profit of 18.1 million USD. This gives an estimate of the value of the long-term thermal storage of 4.8 million USD/a