WorldWideScience

Sample records for warning staging model

  1. Hazard Warning: model misuse ahead

    DEFF Research Database (Denmark)

    Dickey-Collas, M.; Payne, Mark; Trenkel, V.

    2014-01-01

    The use of modelling approaches in marine science, and in particular fisheries science, is explored. We highlight that the choice of model used for an analysis should account for the question being posed or the context of the management problem. We examine a model-classification scheme based......-users (i.e. mangers or policy developers). The combination of attributes leads to models that are considered to have empirical, mechanistic, or analytical characteristics, but not a combination of them. In fisheries science, many examples can be found of models with these characteristics. However, we...

  2. Tsunami Modeling, Forecast and Warning (Invited)

    Science.gov (United States)

    Satake, K.

    2010-12-01

    Tsunami is an infrequent natural hazard; however, once it happens, the effects are devastating and can be on global scale, as demonstrated by the 2004 Indian Ocean tsunami. Deterministic modeling of tsunami generation, propagation and coastal behavior has become popular, at least for earthquake tsunamis. Once the earthquake parameters are specified, tsunami arrival times, heights and current velocity at specific coastal points, and inland inundation area can be estimated. Such modeling has been used to make hazard maps usually by assuming largest possible earthquakes. However, smaller tsunamis than such a worst-case scenario occur more frequently. If the hazard maps are used incorrectly, it may lose reliability of coastal residents. Probabilistic tsunami hazard assessments, similar to Probabilistic Seismic Hazard Analysis, have been made for some coasts. The output is tsunami hazard curves, i.e. annual probability (or return period) for specified coastal tsunami heights. A hazard curve is obtained by integration over the aleatory uncertainties, and a large number of hazard curves are made for each branch of logic tress representing epistemic uncertainty. Probabilistic tsunami hazard analysis is used for design of critical facilities but not popularly used for disaster mitigation. Tsunami warning systems, which have been significantly developed since 2004, rely on seismic and sea-level monitoring and pre-made numerical simulation. Real-time data assimilation of offshore sea level measurements can be used to update the warning levels. Tsunami from the February 2010 Chilean earthquake was recorded on many tide gauges and ocean bottom pressure gauges in the Pacific, before it arrived on the Japanese coast about 22 hours after the earthquake. The tsunami height was up to 2 m on the Japanese coast, causing fishery damage amounting 60 million US dollars, but did not cause any human damage.

  3. Establishment and Practical Application of Flood Warning Stage in Taiwan's River

    Science.gov (United States)

    Yang, Sheng-Hsueh; Chia Yeh, Keh-

    2017-04-01

    In the face of extreme flood events or the possible impact of climate change, non-engineering disaster prevention and early warning work is particularly important. Taiwan is an island topography with more than 3,900 meters of high mountains. The length of the river is less than 100 kilometers. Most of the watershed catchment time is less than 24 hours, which belongs to the river with steep slope and rapid flood. Every year in summer and autumn, several typhoon events invade Taiwan. Typhoons often result in rainfall events in excess of 100 mm/hr or 250 mm/3hr. In the face of Taiwan's terrain and extreme rainfall events, flooding is difficult to avoid. Therefore, most of the river has embankment protection, so that people do not have to face every year flooding caused by economic and life and property losses. However, the river embankment protection is limited. With the increase of the hydrological data, the design criteria for the embankment protection standards in the past was 100 year of flood return period and is now gradually reduced to 25 or 50 year of flood return period. The river authorities are not easy to rise the existing embankment height. The safety of the river embankment in Taiwan is determined by the establishment of the flood warning stage to cope with the possible increase in annual floods and the impact of extreme hydrological events. The flood warning stage is equal to the flood control elevation minus the flood rise rate multiply by the flood early warning time. The control elevation can be the top of the embankment, the design flood level of the river, the embankment gap of the river section, the height of the bridge beam bottom, etc. The flood rise rate is consider the factors such as hydrological stochastic and uncertain rainfall and the effect of flood discharge operation on the flood in the watershed catchment area. The maximum value of the water level difference between the two hours or five hours before the peak value of the analysis

  4. Data Processing Model of Coalmine Gas Early-Warning System

    Institute of Scientific and Technical Information of China (English)

    QIAN Jian-sheng; YIN Hong-sheng; LIU Xiu-rong; HUA Gang; XU Yong-gang

    2007-01-01

    The data processing mode is vital to the performance of an entire coalmine gas early-warning system, especially in real-time performance. Our objective was to present the structural features of coalmine gas data, so that the data could be processed at different priority levels in C language. Two different data processing models, one with priority and the other without priority, were built based on queuing theory. Their theoretical formulas were determined via a M/M/1 model in order to calculate average occupation time of each measuring point in an early-warning program. We validated the model with the gas early-warning system of the Huaibei Coalmine Group Corp. The results indicate that the average occupation time for gas data processing by using the queuing system model with priority is nearly 1/30 of that of the model without priority..

  5. [Study on early-warning of Chinese materia medica price base on ARMA model].

    Science.gov (United States)

    Chang, Feng; Mao, Yang-Dui

    2014-05-01

    This study sets up an early-warning system framework of Chinese materia medica price, using price index as early warning indicator to establish black early-warning model, with indicator of price index volatility and limit line of "price principal". The research divides warning degree into 5 parts named negative heavy warning, negative light warning, no warning, positive light warning and positive heavy warning, with 5 corresponding lights to describe the change level of the medicine price. Then make an early-warning empirical research based on Chengdu Chinese materia medica price index from December in 2010 to October in 2013. ARMA model is applied to forecast index and the result of early-warning is analyzed, and finally farmer households, companies, customers and the government are recommended respectively.

  6. Modelling driver behaviour towards innovative warning devices at railway level crossings.

    Science.gov (United States)

    Tey, Li-Sian; Wallis, Guy; Cloete, Steven; Ferreira, Luis

    2013-03-01

    Improving safety at railway level crossings is costly and as funds are often limited, it is important to search for cost-effective, evidence-based solutions. The effect that the many existing alternative systems have on driver behaviour is not always known. This paper compares driver behaviour towards two novel warning devices (rumble strips and in-vehicle audio warning) at railway level crossings with two conventional warning devices (flashing light and stop sign). Regression models were developed to reflect driver's responses towards the four different types of devices based on data collected from a driving simulation experiment. The regression models include a binary choice model for predicting the probability of a driver stopping or driving through a railway crossing, as well as mixed regression models for predicting the moment at which a driver will produce specific behavioural responses before stopping at a crossing (e.g. initiation of accelerator release and application of foot-pedal brake). Violation results indicated the active systems produced much higher levels of driver compliance than passive devices. Contributing factors, such as age, gender, speed and types of warning devices were found significant at different approach stages to the level crossings. With the application of such behavioural models and traffic conflict techniques in microscopic simulation tools, traffic safety indicators, such as collision likelihood and time-to-collision can be estimated. From these, relative safety comparisons for the different traffic devices are derived. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. A communication model for interlinking national tsunami early warning systems

    Science.gov (United States)

    Lendholt, M.; Hammitzsch, M.; Esbri Palomares, M. A.

    2012-04-01

    The integration of national Tsunami Early Earning Systems (TEWS) to ocean-wide networks is a main objective of the UNESCO Intergovernmental Oceanic Commission (IOC) tsunami programme. The intention is to interlink national TEWSs leveraging warning communication during hazards. For this purpose a communication model has been developed enabling an efficient message exchange within a centre-to-centre (C2C) communication in a system-of-systems environment. The model, designed to be robust and simple, is based on existing interoperability standards from the Open Geospatial Consortium (OGC) and the Organization of the Advancement of Structured Information Standards (OASIS). For the exchange of tsunami warning bulletins the Common Alerting Protocol (CAP) is used. It supports geospatial referencing by addressing geocoded Points of Interests (POIs), Areas of Interest (AOIs) and Coastal Forecast Zones (CFZs). Moreover it supports hazard classification by standardized criticality parameters and the transmission of attachments, e.g. situation maps. The communication model also supports the exchange of sensor observations and measurements such as sea level data or earthquake parameters. For this purpose markup languages of the Sensor Web Enablement (SWE) suite are used. Both communication products, warning bulletins and sensor observations, are embedded in an envelope providing addressing and routing information using the Emergency Data Exchange Language Distribution Element (EDXL-DE). The communication model has been implemented in a first pilot based on Message Oriented Middleware (MOM). Implementation, test and validation was started in the European research project Distant Early Warning System (DEWS) and is continued successively in the project Collaborative, Complex, and Critical Decision Processes in Evolving Crises (TRIDEC). Stimulated by the concepts and results of the German Indonesian Tsunami Early Warning System (GITEWS) and based on its sensor integration platform

  8. Early Warning Models for Systemic Banking Crises in Montenegro

    Directory of Open Access Journals (Sweden)

    Željka Asanović

    2013-06-01

    Full Text Available The purpose of this research is to create an adequate early warning model for systemic banking crises in Montenegro. The probability of banking crisis occurrence is calculated using discrete dependent variable models, more precisely, estimating logit regression. Afterwards, seven simple logit regressions that individually have two explanatory variables are estimated. Adequate weights have been assigned to all seven regressions using the technique of Bayesian model averaging. The advantage of this technique is that it takes into account the model uncertainty by considering various combinations of models in order to minimize the author’s subjective judgment when determining reliable early warning indicators. The results of Bayesian model averaging largely coincide with the results of a previously estimated dynamic logit model. Indicators of credit expansion, thanks to their performances, have a dominant role in early warning models for systemic banking crises in Montenegro. The results have also shown that the Montenegrin banking system is significantly exposed to trends on the global level.

  9. Earthquake Early Warning Beta Users: Java, Modeling, and Mobile Apps

    Science.gov (United States)

    Strauss, J. A.; Vinci, M.; Steele, W. P.; Allen, R. M.; Hellweg, M.

    2014-12-01

    Earthquake Early Warning (EEW) is a system that can provide a few to tens of seconds warning prior to ground shaking at a user's location. The goal and purpose of such a system is to reduce, or minimize, the damage, costs, and casualties resulting from an earthquake. A demonstration earthquake early warning system (ShakeAlert) is undergoing testing in the United States by the UC Berkeley Seismological Laboratory, Caltech, ETH Zurich, University of Washington, the USGS, and beta users in California and the Pacific Northwest. The beta users receive earthquake information very rapidly in real-time and are providing feedback on their experiences of performance and potential uses within their organization. Beta user interactions allow the ShakeAlert team to discern: which alert delivery options are most effective, what changes would make the UserDisplay more useful in a pre-disaster situation, and most importantly, what actions users plan to take for various scenarios. Actions could include: personal safety approaches, such as drop cover, and hold on; automated processes and procedures, such as opening elevator or fire stations doors; or situational awareness. Users are beginning to determine which policy and technological changes may need to be enacted, and funding requirements to implement their automated controls. The use of models and mobile apps are beginning to augment the basic Java desktop applet. Modeling allows beta users to test their early warning responses against various scenarios without having to wait for a real event. Mobile apps are also changing the possible response landscape, providing other avenues for people to receive information. All of these combine to improve business continuity and resiliency.

  10. A geomagnetically induced current warning system: model development and validation

    Science.gov (United States)

    McKay, A.; Clarke, E.; Reay, S.; Thomson, A.

    Geomagnetically Induced Currents (GIC), which can flow in technological systems at the Earth's surface, are a consequence of magnetic storms and Space Weather. A well-documented practical problem for the power transmission industry is that GIC can affect the lifetime and performance of transformers within the power grid. Operational mitigation is widely considered to be one of the best strategies to manage the Space Weather and GIC risk. Therefore in the UK a magnetic storm warning and GIC monitoring and analysis programme has been under development by the British Geological Survey and Scottish Power plc (the power grid operator for Central Scotland) since 1999. Under the auspices of the European Space Agency's service development activities BGS is developing the capability to meet two key user needs that have been identified. These needs are, firstly, the development of a near real-time solar wind shock/ geomagnetic storm warning, based on L1 solar wind data and, secondly, the development of an integrated surface geo-electric field and power grid network model that should allow prediction of GIC throughout the power grid in near real time. While the final goal is a `seamless package', the components of the package utilise diverse scientific techniques. We review progress to date with particular regard to the validation of the individual components of the package. The Scottish power grid response to the October 2003 magnetic storms is also discussed and model and validation data are presented.

  11. Land Surface Modeling Applications for Famine Early Warning

    Science.gov (United States)

    McNally, A.; Verdin, J. P.; Peters-Lidard, C. D.; Arsenault, K. R.; Wang, S.; Kumar, S.; Shukla, S.; Funk, C. C.; Pervez, M. S.; Fall, G. M.; Karsten, L. R.

    2015-12-01

    AGU 2015 Fall Meeting Session ID#: 7598 Remote Sensing Applications for Water Resources Management Land Surface Modeling Applications for Famine Early Warning James Verdin, USGS EROS Christa Peters-Lidard, NASA GSFC Amy McNally, NASA GSFC, UMD/ESSIC Kristi Arsenault, NASA GSFC, SAIC Shugong Wang, NASA GSFC, SAIC Sujay Kumar, NASA GSFC, SAIC Shrad Shukla, UCSB Chris Funk, USGS EROS Greg Fall, NOAA Logan Karsten, NOAA, UCAR Famine early warning has traditionally required close monitoring of agro-climatological conditions, putting them in historical context, and projecting them forward to anticipate end-of-season outcomes. In recent years, it has become necessary to factor in the effects of a changing climate as well. There has also been a growing appreciation of the linkage between food security and water availability. In 2009, Famine Early Warning Systems Network (FEWS NET) science partners began developing land surface modeling (LSM) applications to address these needs. With support from the NASA Applied Sciences Program, an instance of the Land Information System (LIS) was developed to specifically support FEWS NET. A simple crop water balance model (GeoWRSI) traditionally used by FEWS NET took its place alongside the Noah land surface model and the latest version of the Variable Infiltration Capacity (VIC) model, and LIS data readers were developed for FEWS NET precipitation forcings (NOAA's RFE and USGS/UCSB's CHIRPS). The resulting system was successfully used to monitor and project soil moisture conditions in the Horn of Africa, foretelling poor crop outcomes in the OND 2013 and MAM 2014 seasons. In parallel, NOAA created another instance of LIS to monitor snow water resources in Afghanistan, which are an early indicator of water availability for irrigation and crop production. These successes have been followed by investment in LSM implementations to track and project water availability in Sub-Saharan Africa and Yemen, work that is now underway. Adoption of

  12. Model slope infiltration experiments for shallow landslides early warning

    Science.gov (United States)

    Damiano, E.; Greco, R.; Guida, A.; Olivares, L.; Picarelli, L.

    2009-04-01

    Occurrence of fast landslides has become more and more dangerous during the last decades, due to the increased density of settlements, industrial plants and infrastructures. Such problem is particularly worrying in Campania (Southern Italy), where the fast population growth led a diffuse building activity without planning: indeed, recent flowslides caused hundreds of victims and heavy damages to buildings, roads and other infrastructures. Large mountainous areas in Campania are mantled by loose pyroclastic granular soils up to a depth of a few meters from top soil surface. These soils have usually a grain size that falls in the domain of silty sands, including pumice interbeds (gravelly sands), with saturated hydraulic conductivities up to the order of 10-1 cm/min. Such deposits often cover steep slopes, which stability is guaranteed by the apparent cohesion due to suction under unsaturated conditions, that are the most common conditions for these slopes [Olivares and Picarelli, 2001]. Whereas rainfall infiltration causes soil to approach saturation, suction vanishes and slope failure may occur. Besides soil physical properties, landslide triggering is influenced by several factors, such as rainfall intensity, soil initial moisture and suction, slope inclination, boundary conditions. Whereas slope failure occurs with soil close to being saturated, landslide may develop in form of fast and destructive flowslide. Calibration of reliable mathematical models of such a complex phenomenon requires availability of experimental observations of the major variables of interest, such as soil moisture and suction, soil deformation and displacements, pore water pressure, during the entire process of infiltration until slope failure. Due to the sudden trigger and extremely rapid propagation of such type of landslides, such data sets are rarely available for natural slopes where flowslides occurred. As a consequence landslide risk assessment and early warning in Campania rely on

  13. Regional Integrated Meteorological Forecasting and Warning Model for Geological Hazards Based on Logistic Regression

    Institute of Scientific and Technical Information of China (English)

    XU Jing; YANG Chi; ZHANG Guoping

    2007-01-01

    Information model is adopted to integrate factors of various geosciences to estimate the susceptibility of geological hazards. Further combining the dynamic rainfall observations, Logistic regression is used for modeling the probabilities of geological hazard occurrences, upon which hierarchical warnings for rainfall-induced geological hazards are produced. The forecasting and warning model takes numerical precipitation forecasts on grid points as its dynamic input, forecasts the probabilities of geological hazard occurrences on the same grid, and translates the results into likelihoods in the form of a 5-level hierarchy. Validation of the model with observational data for the year 2004 shows that 80% of the geological hazards of the year have been identified as "likely enough to release warning messages". The model can satisfy the requirements of an operational warning system, thus is an effective way to improve the meteorological warnings for geological hazards.

  14. Development of Urban Inundation Warning Model at Cyclic Artificial Water Way in Song-do International City, Republic of Korea

    Science.gov (United States)

    Lee, T.; Lee, C.; Kim, H.

    2016-12-01

    Abstract Song-do international city was constructed by reclaiming land from the coastal waters of Yeonsu-gu, Incheon Metropolitan City, Republic of Korea. The □-shaped cyclic artificial water way has been considered for improving water quality, waterfront and internal drainage in Song-do international city. By improving water quality, various marine facilities, such as marina, artificial beach, marine terminal, and so on, will be set up around the artificial water way for the waterfront. Since the water stage of the artificial water way changes depending on water gates operations, it is necessary to develop an urban inundation warning model to evaluate safeties of the waterfront facilities and its passengers. By considering characteristics of urban watershed, we calculate discharge flowing into the water way using XP-SWMM model. As a result of estimating 100-year flood frequency, although there are slight differences in drainage sections, the maximum flood discharge occurs in 90-min rainfall duration. In order to consider impacts of tide and hydraulic structure, we establish Inland drainage plans through the analysis of unsteady flow using HEC-RAS. The urban inundation warning model is configured to issue a warning when the water plain elevation exceeds EL. 1.5m which is usually managed at EL. 1.0m. In this study, the design flood stage of artificial water way and urban inundation warning model are developed for Song-do international city, and therefore it is expected that a reliability of management and operation of the waterfront facilities is improved. Keywords : Artificial Water Way; Waterfront; Urban Inundation Warning Model. Acknowlegement This research was supported by a grant [MPSS-NH-2015-79] through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

  15. Monitoring and modeling agricultural drought for famine early warning (Invited)

    Science.gov (United States)

    Verdin, J. P.; Funk, C.; Budde, M. E.; Lietzow, R.; Senay, G. B.; Smith, R.; Pedreros, D.; Rowland, J.; Artan, G. A.; Husak, G. J.; Michaelsen, J.; Adoum, A.; Galu, G.; Magadzire, T.; Rodriguez, M.

    2009-12-01

    The Famine Early Warning Systems Network (FEWS NET) makes quantitative estimates of food insecure populations, and identifies the places and periods during which action must be taken to assist them. Subsistence agriculture and pastoralism are the predominant livelihood systems being monitored, and they are especially drought-sensitive. At the same time, conventional climate observation networks in developing countries are often sparse and late in reporting. Consequently, remote sensing has played a significant role since FEWS NET began in 1985. Initially there was heavy reliance on vegetation index imagery from AVHRR to identify anomalies in landscape greenness indicative of drought. In the latter part of the 1990s, satellite rainfall estimates added a second, independent basis for identification of drought. They are used to force crop water balance models for the principal rainfed staple crops in twenty FEWS NET countries. Such models reveal seasonal moisture deficits associated with yield reduction on a spatially continuous basis. In 2002, irrigated crops in southwest Asia became a concern, and prompted the implementation of a gridded energy balance model to simulate the seasonal mountain snow pack, the main source of irrigation water. MODIS land surface temperature data are also applied in these areas to directly estimate actual seasonal evapotranspiration on the irrigated lands. The approach reveals situations of reduced irrigation water supply and crop production due to drought. The availability of MODIS data after 2000 also brought renewed interest in vegetation index imagery. MODIS NDVI data have proven to be of high quality, thanks to significant spectral and spatial resolution improvements over AVHRR. They are vital to producing rapid harvest assessments for drought-impacted countries in Africa and Asia. The global food crisis that emerged in 2008 has led to expansion of FEWS NET monitoring to over 50 additional countries. Unlike previous practice, these

  16. A rainfall-based warning model for shallow landslides

    Science.gov (United States)

    Zeng, Yi-Chao; Wang, Ji-Shang; Jan, Chyan-Deng; Yin, Hsiao-Yuan; Lo, Wen-Chun

    2016-04-01

    According to the statistical data of past rainfall events, the climate has changed in recent decades. Rainfall patterns have presented a more concentrated, high-intensity and long-duration trend in Taiwan. The most representative event is Typhoon Morakot which induced a total of 67 enormous landslides by the extreme amount of rain during August 7 to 10 in 2009 and resulted in the heaviest casualties in southern Taiwan. In addition, the nature of vulnerability such as steep mountains and rushing rivers, fragile geology and loose surface soil results in more severe sediment-relative disasters, in which shallow landslides are widespread hazards in mountainous regions. This research aims to develop and evaluate a model for predicting shallow landslides triggered by rainfall in mountainous area. Considering the feasibility of large-scale application and practical operation, the statistical techniques is adopted to form the landslide model based on abundant historical rainfall data and landslide events. The 16 landslide inventory maps and 15 variation results by comparing satellite images taken before and after the rainfall event were interpreted and delineated since 2004 to 2011. Logit model is utilized for interpreting the relationship between rainfall characteristics and landslide events delineated from satellite. Based on the analysis results of logistic regression, the rainfall factors that are highly related to shallow landslide occurrence are selected which are 3 hours rainfall intensity I3 (mm/hr) and the effective cumulative precipitation Rt (mm) including accumulated rainfall at time t and antecedent rainfall. A landslide rainfall triggering index (LRTI) proposed for assessing the occurrence potential of shallow landslides is defined as the product of I3 and Rt. A form of probability of shallow landslide triggered threshold is proposed to offer a measure of the likelihood of landslide occurrence. Two major critical lines which represent the lower and upper

  17. Landslide susceptibility and early warning model for shallow landslide in Taiwan

    Science.gov (United States)

    Huang, Chun-Ming; Wei, Lun-Wei; Chi, Chun-Chi; Chang, Kan-Tsun; Lee, Chyi-Tyi

    2017-04-01

    This study aims to development a regional susceptibility model and warning threshold as well as the establishment of early warning system in order to prevent and reduce the losses caused by rainfall-induced shallow landslides in Taiwan. For the purpose of practical application, Taiwan is divided into nearly 185,000 slope units. The susceptibility and warning threshold of each slope unit were analyzed as basic information for disaster prevention. The geological characteristics, mechanism and the occurrence time of landslides were recorded for more than 900 cases through field investigation and interview of residents in order to discuss the relationship between landslides and rainfall. Logistic regression analysis was performed to evaluate the landslide susceptibility and an I3-R24 rainfall threshold model was proposed for the early warning of landslides. The validations of recent landslide cases show that the model was suitable for the warning of regional shallow landslide and most of the cases can be warned 3 to 6 hours in advanced. We also propose a slope unit area weighted method to establish local rainfall threshold on landslide for vulnerable villages in order to improve the practical application. Validations of the local rainfall threshold also show a good agreement to the occurrence time reported by newspapers. Finally, a web based "Rainfall-induced Landslide Early Warning System" is built and connected to real-time radar rainfall data so that landslide real-time warning can be achieved. Keywords: landslide, susceptibility analysis, rainfall threshold

  18. Flash flood warning based on fully dynamic hydrology modelling

    Science.gov (United States)

    Pejanovic, Goran; Petkovic, Slavko; Cvetkovic, Bojan; Nickovic, Slobodan

    2016-04-01

    Numerical hydrologic modeling has achieved limited success in the past due to, inter alia, lack of adequate input data. Over the last decade, data availability has improved substantially. For modelling purposes, high-resolution data on topography, river routing, and land cover and soil features have meanwhile become available, as well as the observations such as radar precipitation information. In our study, we have implemented the HYPROM model (Hydrology Prognostic Model) to predict a flash flood event at a smaller-scale basin in Southern Serbia. HYPROM is based on the full set of governing equations for surface hydrological dynamics, in which momentum components, along with the equation of mass continuity, are used as full prognostic equations. HYPROM also includes a river routing module serving as a collector for the extra surface water. Such approach permits appropriate representation of different hydrology scales ranging from flash floods to flows of large and slow river basins. The use of full governing equations, if not appropriately parameterized, may lead to numerical instability systems when the surface water in a model is vanishing. To resolve these modelling problems, an unconditionally stable numerical scheme and a method for height redistribution avoiding shortwave height noise have been developed in HYPROM, which achieve numerical convergence of u, v and h when surface water disappears. We have applied HYPROM, driven by radar-estimated precipitation, to predict flash flooding occurred over smaller and medium-size river basins. Two torrential rainfall cases have been simulated to check the accuracy of the model: the exceptional flooding of May 2014 in Western Serbia, and the convective flash flood of January 2015 in Southern Serbia. The second episode has been successfully predicted by HYPROM in terms of timing and intensity six hours before the event occurred. Such flash flood warning system is in preparation to be operationally implemented in the

  19. Developing models to estimate the benefits from flood warnings

    OpenAIRE

    Parker, Dennis J.; Priest, Sally J.; Schildt, Anne; Handmer, John W.

    2008-01-01

    Flood forecasting and warning systems have a significant role to play within integrated flood risk management, either in combination with mobile structural flood defences or as part of an approach which combines a number of non-structural measures. In theory the benefits of flood warnings, in terms of community security, protection of life and flood damage reduction, should be large. The theoretical benefit potential is being driven upwards by important advances in the predictive sciences, an...

  20. Warning Model for Shallow Landslides Induced by Extreme Rainfall

    Directory of Open Access Journals (Sweden)

    Lien-Kwei Chien

    2015-08-01

    Full Text Available In this study, the geophysical properties of the landslide-prone catchment of the Gaoping River in Taiwan were investigated using zones based on landslide history in conjunction with landslide analysis using a deterministic approach based on the TRIGRS (Transient Rainfall Infiltration and Grid-based Regional Slope-Stability model. Typhoon Morakot in 2009 was selected as a simulation scenario to calibrate the combination of geophysical parameters in each zone before analyzing changes in the factor of safety (FS. Considering the amount of response time required for typhoons, suitable FS thresholds for landslide warnings are proposed for each town in the catchment area. Typhoon Fanapi of 2010 was used as a test scenario to verify the applicability of the FS as well as the efficacy of the cumulative rainfall thresholds derived in this study. Finally, the amount of response time provided by the FS thresholds in cases of yellow and red alerts was determined. All five of the landslide events reported by the Soil and Water Conservation Bureau were listed among the unstable sites identified in the proposed model, thereby demonstrating its effectiveness and accuracy in determining unstable areas and areas that require evacuation. These cumulative rainfall thresholds provide a valuable reference to guide disaster prevention authorities in the issuance of yellow and red alerts with the ability to reduce losses and save lives.

  1. APPLICATION OF FUZZY OPTIMIZATION MODEL IN ECOLOGICAL SECURITY PRE-WARNING

    Institute of Scientific and Technical Information of China (English)

    WU Kai-ya; HU Shu-heng; SUN Shi-qun

    2005-01-01

    Ecological security is a vital problem that people all over the world today have to face and solve, and the situation of ecological security is getting more and more severe and has begun to impede heavily the sustainable development of social economy. Ecological environment pre-warning has become a hotspot for the modern environment science. This paper introduces the theories of ecological security pre-warning and tries to constitute a pre-warning model of ecological security. In terms of pressure-state-response model, the pre-warning guide line of ecological security is constructed while the pre-warning degree judging model of ecological security is established based on fuzzy optimization. As a case, the model is used to assess the present condition pre-warning of the ecological security of Anhui Province. The result is in correspondence with the real condition: the ecological security situations of 8 cities are dangerous and 9 cities are secure. The result shows that this model is scientific and effective for regional ecological security pre-warning.

  2. A two-stage logistic regression-ANN model for the prediction of distress banks: Evidence from 11 emerging countries

    National Research Council Canada - National Science Library

    Shu Ling Lin

    2010-01-01

      This paper proposes a new approach of two-stage hybrid model of logistic regression-ANN for the construction of a financial distress warning system for banking industry in emerging market during 1998-2006...

  3. Microsimulation modelling of driver behaviour towards alternative warning devices at railway level crossings.

    Science.gov (United States)

    Tey, Li-Sian; Zhu, Sicong; Ferreira, Luis; Wallis, Guy

    2014-10-01

    Level crossings are amongst the most complex of road safety issues, due to the addition of rail infrastructure, trains and train operations. The differences in the operational characteristics of different warning devices together with varying crossing, traffic or/and train characteristics, cause different driver behaviour at crossings. This paper compares driver behaviour towards two novel warning devices (rumble strips and in-vehicle audio warning) with two conventional warning devices (flashing light and stop sign) at railway level crossings using microsimulation modelling. Two safety performance indicators directly related to collision risks, violation and time-to-collision, were adopted. Results indicated the active systems were more effective at reducing likely collisions compared to passive devices. With the combined application of driving simulation and traffic microsimulation modelling, traffic safety performance indicators for a level crossing can be estimated. From these, relative safety comparisons for the different traffic devices are derived, or even for absolute safety evaluation with proper calibration from field investigations.

  4. [Ecological security early-warning in Zhoushan Islands based on variable weight model].

    Science.gov (United States)

    Zhou, Bin; Zhong, Lin-sheng; Chen, Tian; Zhou, Rui

    2015-06-01

    Ecological security early warning, as an important content of ecological security research, is of indicating significance in maintaining regional ecological security. Based on driving force, pressure, state, impact and response (D-P-S-I-R) framework model, this paper took Zhoushan Islands in Zhejiang Province as an example to construct the ecological security early warning index system, test degrees of ecological security early warning of Zhoushan Islands from 2000 to 2012 by using the method of variable weight model, and forecast ecological security state of 2013-2018 by Markov prediction method. The results showed that the variable weight model could meet the study needs of ecological security early warning of Zhoushan Islands. There was a fluctuant rising ecological security early warning index from 0.286 to 0.484 in Zhoushan Islands between year 2000 and 2012, in which the security grade turned from "serious alert" into " medium alert" and the indicator light turned from "orange" to "yellow". The degree of ecological security warning was "medium alert" with the light of "yellow" for Zhoushan Islands from 2013 to 2018. These findings could provide a reference for ecological security maintenance of Zhoushan Islands.

  5. Tool for evaluating the evolution Space Weather Regional Warning Centers under the innovation point of view: the Case Study of the Embrace Space Weather Program Early Stages

    Science.gov (United States)

    Denardini, Clezio Marcos

    2016-07-01

    We have developed a tool for measuring the evolutional stage of the space weather regional warning centers using the approach of the innovative evolution starting from the perspective presented by Figueiredo (2009, Innovation Management: Concepts, metrics and experiences of companies in Brazil. Publisher LTC, Rio de Janeiro - RJ). It is based on measuring the stock of technological skills needed to perform a certain task that is (or should) be part of the scope of a space weather center. It also addresses the technological capacity for innovation considering the accumulation of technological and learning capabilities, instead of the usual international indices like number of registered patents. Based on this definition, we have developed a model for measuring the capabilities of the Brazilian Study and Monitoring Program Space Weather (Embrace), a program of the National Institute for Space Research (INPE), which has gone through three national stages of development and an international validation step. This program was created in 2007 encompassing competence from five divisions of INPE in order to carry out the data collection and maintenance of the observing system in space weather; to model processes of the Sun-Earth system; to provide real-time information and to forecast space weather; and provide diagnostic their effects on different technological systems. In the present work, we considered the issues related to the innovation of micro-processes inherent to the nature of the Embrace program, not the macro-economic processes, despite recognizing the importance of these. During the development phase, the model was submitted to five scientists/managers from five different countries member of the International Space Environment Service (ISES) who presented their evaluations, concerns and suggestions. It was applied to the Embrace program through an interview form developed to be answered by professional members of regional warning centers. Based on the returning

  6. Realization and Application of Customer Attrition Early Warning Model in Security Company

    Directory of Open Access Journals (Sweden)

    Shen Yizhen

    2012-09-01

    Full Text Available In this paper, we propose the customer attrition early warning model based on data warehouse and data mining technologies, which is achieved and applied in our security company. The modeling variables can be selected by means of the combination with decision tree and the gradual regression in Logistic regression. Then customer attrition early warning model can be constructed based on Logistic regression. The results show that the model can strongly promote the customer attrition capturing rate, push on the building of the company customer marketing management and customer service management organization, and economize the marketing cost. The company profits promotion and trade competitive power can be promised.

  7. A study of landslide warning based on the RTI model in Korea

    Science.gov (United States)

    Chae, Byung-Gon; Liu, Ko-Fei; Choi, Junghae

    2016-04-01

    This study performed a feasibility study to make a warning of landslides in Korea based on the Rainfall Triggering Index (RTI) model which had been proposed by Jan et al. (2004). The RTI model is a hyperbolic I-R model, which is defined as the product of rainfall intensity (mm/hr) and effective accumulated rainfall (mm). Time of the calculated RTI value exceeding the threshold of RTI 70, meaning landslide probability of 70%, is a pre-warning time of landslide and a period between a pre-warning time and a landslide occurrence time is a responding time. Rainfall data which had been provided by the Korea Meteorological Administration was acquired at multiple locations near landslide areas. The starting time of rainfall was defined as the time at which the hourly rainfall (mm) larger than 4 mm, and when hourly rainfall (mm) less than 4mm and lasting at least 6 hours was the rainfall event ending time (Jan, 2004). The period of antecedent rainfall was determined as two days prior to landslide occurrence, because average permeability coefficient in soils is large and average duration of the effective rainfall is not exceeded two days in Korea. To analyze appropriate threshold of RTI values for landslide pre-warning, this study evaluated rainfall intensities to calculate reasonable RTI values. Based on the original RTI model using 60 minutes rainfall intensity, rainfall intensities for 30 minutes and 10 minutes were analyzed. Results show that there was no false warning using 10 minute model, but there are 20% events are never warned using 60 minutes model. The pre-warning time in 10 minutes model is earlier than 60 minutes model in most of the cases. The evacuation time can get 1 hour to 12 hours with 10 minutes model than using 60 minutes model. However, 10 minutes model is more sensitive than 60 minutes model. If we apply 10 minutes warning model in the future, it may increase the false alert rate. Therefore it needs more events of landslides to modify this model

  8. Behavior of Early Warnings near the Critical Temperature in the Two-Dimensional Ising Model

    Science.gov (United States)

    Morales, Irving O.; Landa, Emmanuel; Angeles, Carlos Calderon; Toledo, Juan C.; Rivera, Ana Leonor; Temis, Joel Mendoza; Frank, Alejandro

    2015-01-01

    Among the properties that are common to complex systems, the presence of critical thresholds in the dynamics of the system is one of the most important. Recently, there has been interest in the universalities that occur in the behavior of systems near critical points. These universal properties make it possible to estimate how far a system is from a critical threshold. Several early-warning signals have been reported in time series representing systems near catastrophic shifts. The proper understanding of these early-warnings may allow the prediction and perhaps control of these dramatic shifts in a wide variety of systems. In this paper we analyze this universal behavior for a system that is a paradigm of phase transitions, the Ising model. We study the behavior of the early-warning signals and the way the temporal correlations of the system increase when the system is near the critical point. PMID:26103513

  9. Behavior of Early Warnings near the Critical Temperature in the Two-Dimensional Ising Model.

    Directory of Open Access Journals (Sweden)

    Irving O Morales

    Full Text Available Among the properties that are common to complex systems, the presence of critical thresholds in the dynamics of the system is one of the most important. Recently, there has been interest in the universalities that occur in the behavior of systems near critical points. These universal properties make it possible to estimate how far a system is from a critical threshold. Several early-warning signals have been reported in time series representing systems near catastrophic shifts. The proper understanding of these early-warnings may allow the prediction and perhaps control of these dramatic shifts in a wide variety of systems. In this paper we analyze this universal behavior for a system that is a paradigm of phase transitions, the Ising model. We study the behavior of the early-warning signals and the way the temporal correlations of the system increase when the system is near the critical point.

  10. Three stage semelparous Leslie models.

    Science.gov (United States)

    Cushing, J M

    2009-07-01

    Nonlinear Leslie matrix models have a long history of use for modeling the dynamics of semelparous species. Semelparous models, as do nonlinear matrix models in general, undergo a transcritical equilibrium bifurcation at inherent net reproductive number R(0) = 1 where the extinction equilibrium loses stability. Semelparous models however do not fall under the purview of the general theory because this bifurcation is of higher co-dimension. This mathematical fact has biological implications that relate to a dichotomy of dynamic possibilities, namely, an equilibration with over lapping age classes as opposed to an oscillation in which age classes are periodically missing. The latter possibility makes these models of particular interest, for example, in application to the well known outbreaks of periodical insects. While the nature of the bifurcation at R(0) = 1 is known for two-dimensional semelparous Leslie models, only limited results are available for higher dimensional models. In this paper I give a thorough accounting of the bifurcation at R(0) = 1 in the three-dimensional case, under some monotonicity assumptions on the nonlinearities. In addition to the bifurcation of positive equilibria, there occurs a bifurcation of invariant loops that lie on the boundary of the positive cone. I describe the geometry of these loops, classify them into three distinct types, and show that they consist of either one or two three-cycles and heteroclinic orbits connecting (the phases of) these cycles. Furthermore, I determine stability and instability properties of these loops, in terms of model parameters, as well as those of the positive equilibria. The analysis also provides the global dynamics on the boundary of the cone. The stability and instability conditions are expressed in terms of certain measures of the strength and the symmetry/asymmetry of the inter-age class competitive interactions. Roughly speaking, strong inter-age class competitive interactions promote

  11. Financial crisis early-warning model of listed companies based on predicted value

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To establish a financial early-warning model with high accuracy of discrimination and achieve the aim of long-term prediction, principal component analysis (PCA), Fisher discriminant, together with grey forecasting models are used at the same time. 110 A-share companies listed on the Shanghai and Shenzhen stock exchange are selected as research samples. And 10 extractive factors with 89.746% of all the original information are determined by applying PCA, which obtains the goal of dimension reduction without...

  12. Flood Forecast and Early Warning with High-Resolution Ensemble Rainfall from Numerical Weather Prediction Model

    OpenAIRE

    Yu, Wansik; NAKAKITA, Eiichi; Jung, Kwansue

    2016-01-01

    This paper investigates the applicability of ensemble forecasts of numerical weather prediction (NWP) model for flood forecasting. In this study, 10 km resolution ensemble rainfalls forecast and their downscaled forecasts of 2 km resolution were used in the hydrologic model as input data for flood forecasting and application of flood early warning. Ensemble data consists of 51 members and 48 hr forecast time. Ensemble outputs are verified spatially whether they can produce suitable rainfall p...

  13. A Neutral Network based Early Eathquake Warning model in California region

    Science.gov (United States)

    Xiao, H.; MacAyeal, D. R.

    2016-12-01

    Early Earthquake Warning systems could reduce loss of lives and other economic impact resulted from natural disaster or man-made calamity. Current systems could be further enhanced by neutral network method. A 3 layer neural network model combined with onsite method was deployed in this paper to improve the recognition time and detection time for large scale earthquakes.The 3 layer neutral network early earthquake warning model adopted the vector feature design for sample events happened within 150 km radius of the epicenters. Dataset used in this paper contained both destructive events and small scale events. All the data was extracted from IRIS database to properly train the model. In the training process, backpropagation algorithm was used to adjust the weight matrices and bias matrices during each iteration. The information in all three channels of the seismometers served as the source in this model. Through designed tests, it was indicated that this model could identify approximately 90 percent of the events' scale correctly. And the early detection could provide informative evidence for public authorities to make further decisions. This indicated that neutral network model could have the potential to strengthen current early warning system, since the onsite method may greatly reduce the responding time and save more lives in such disasters.

  14. Risk-based modeling of early warning systems for pollution accidents.

    Science.gov (United States)

    Grayman, W M; Males, R M

    2002-01-01

    An early warning system is a mechanism for detecting, characterizing and providing notification of a source water contamination event (spill event) in order to mitigate the impact of contamination. Spill events are highly probabilistic occurrences with major spills, which can have very significant impacts on raw water sources of drinking water, being relatively rare. A systematic method for designing and operating early warning systems that considers the highly variable, probabilistic nature of many aspects of the system is described. The methodology accounts for the probability of spills, behavior of monitoring equipment, variable hydrology, and the probability of obtaining information about spills independent of a monitoring system. Spill Risk, a risk-based model using Monte Carlo simulation techniques has been developed and its utility has been demonstrated as part of an AWWA Research Foundation sponsored project. The model has been applied to several hypothetical river situations and to an actual section of the Ohio River. Additionally, the model has been systematically applied to a wide range of conditions in order to develop general guidance on design of early warning systems.

  15. Application of satellite products and hydrological modelling for flood early warning

    Science.gov (United States)

    Koriche, Sifan A.; Rientjes, Tom H. M.

    2016-06-01

    Floods have caused devastating impacts to the environment and society in Awash River Basin, Ethiopia. Since flooding events are frequent, this marks the need to develop tools for flood early warning. In this study, we propose a satellite based flood index to identify the runoff source areas that largely contribute to extreme runoff production and floods in the basin. Satellite based products used for development of the flood index are CMORPH (Climate Prediction Center MORPHing technique: 0.25° by 0.25°, daily) product for calculation of the Standard Precipitation Index (SPI) and a Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) for calculation of the Topographic Wetness Index (TWI). Other satellite products used in this study are for rainfall-runoff modelling to represent rainfall, potential evapotranspiration, vegetation cover and topography. Results of the study show that assessment of spatial and temporal rainfall variability by satellite products may well serve in flood early warning. Preliminary findings on effectiveness of the flood index developed in this study indicate that the index is well suited for flood early warning. The index combines SPI and TWI, and preliminary results illustrate the spatial distribution of likely runoff source areas that cause floods in flood prone areas.

  16. Conceptual Model for Automatic Early Warning Information System of Infectious Diseases Based on Internet Reporting Surveillance System

    Institute of Scientific and Technical Information of China (English)

    JIA-QI MA; LI-PING WANG; XUAO-PENG QI; XIAO-MING SHI; GONG-HUAN YANG

    2007-01-01

    Objective To establish a conceptual model of automatic early warning of infectious diseases based on internet reporting surveillance system,with a view to realizing an automated warning system on a daily basis and timely identifying potential outbreaks of infectious diseases. Methods The statistic conceptual model was established using historic surveillance data with movable percentile method.Results Based on the infectious disease surveillance information platform,the conceptualmodelfor early warning was established.The parameter,threshold,and revised sensitivity and specificity of early warning value were changed to realize dynamic alert of infectious diseases on a daily basis.Conclusion The instructive conceptual model of dynamic alert can be used as a validating tool in institutions of infectious disease surveillance in different districts.

  17. Enhancing Community Based Early Warning Systems in Nepal with Flood Forecasting Using Local and Global Models

    Science.gov (United States)

    Dugar, Sumit; Smith, Paul; Parajuli, Binod; Khanal, Sonu; Brown, Sarah; Gautam, Dilip; Bhandari, Dinanath; Gurung, Gehendra; Shakya, Puja; Kharbuja, RamGopal; Uprety, Madhab

    2017-04-01

    Operationalising effective Flood Early Warning Systems (EWS) in developing countries like Nepal poses numerous challenges, with complex topography and geology, sparse network of river and rainfall gauging stations and diverse socio-economic conditions. Despite these challenges, simple real-time monitoring based EWSs have been in place for the past decade. A key constraint of these simple systems is the very limited lead time for response - as little as 2-3 hours, especially for rivers originating from steep mountainous catchments. Efforts to increase lead time for early warning are focusing on imbedding forecasts into the existing early warning systems. In 2016, the Nepal Department of Hydrology and Meteorology (DHM) piloted an operational Probabilistic Flood Forecasting Model in major river basins across Nepal. This comprised a low data approach to forecast water levels, developed jointly through a research/practitioner partnership with Lancaster University and WaterNumbers (UK) and the International NGO Practical Action. Using Data-Based Mechanistic Modelling (DBM) techniques, the model assimilated rainfall and water levels to generate localised hourly flood predictions, which are presented as probabilistic forecasts, increasing lead times from 2-3 hours to 7-8 hours. The Nepal DHM has simultaneously started utilizing forecasts from the Global Flood Awareness System (GLoFAS) that provides streamflow predictions at the global scale based upon distributed hydrological simulations using numerical ensemble weather forecasts from the ECMWF (European Centre for Medium-Range Weather Forecasts). The aforementioned global and local models have already affected the approach to early warning in Nepal, being operational during the 2016 monsoon in the West Rapti basin in Western Nepal. On 24 July 2016, GLoFAS hydrological forecasts for the West Rapti indicated a sharp rise in river discharge above 1500 m3/sec (equivalent to the river warning level at 5 meters) with 53

  18. Developing a dengue early warning system using time series model: Case study in Tainan, Taiwan

    Science.gov (United States)

    Chen, Xiao-Wei; Jan, Chyan-Deng; Wang, Ji-Shang

    2017-04-01

    Dengue fever (DF) is a climate-sensitive disease that has been emerging in southern regions of Taiwan over the past few decades, causing a significant health burden to affected areas. This study aims to propose a predictive model to implement an early warning system so as to enhance dengue surveillance and control in Tainan, Taiwan. The Seasonal Autoregressive Integrated Moving Average (SARIMA) model was used herein to forecast dengue cases. Temporal correlation between dengue incidences and climate variables were examined by Pearson correlation analysis and Cross-correlation tests in order to identify key determinants to be included as predictors. The dengue surveillance data between 2000 and 2009, as well as their respective climate variables were then used as inputs for the model. We validated the model by forecasting the number of dengue cases expected to occur each week between January 1, 2010 and December 31, 2015. In addition, we analyzed historical dengue trends and found that 25 cases occurring in one week was a trigger point that often led to a dengue outbreak. This threshold point was combined with the season-based framework put forth by the World Health Organization to create a more accurate epidemic threshold for a Tainan-specific warning system. A Seasonal ARIMA model with the general form: (1,0,5)(1,1,1)52 is identified as the most appropriate model based on lowest AIC, and was proven significant in the prediction of observed dengue cases. Based on the correlation coefficient, Lag-11 maximum 1-hr rainfall (r=0.319, Pdengue surveillance and control in Tainan, Taiwan. We conclude that this timely dengue early warning system will enable public health services to allocate limited resources more effectively, and public health officials to adjust dengue emergency response plans to their maximum capabilities.

  19. Staged Models for Interdisciplinary Research

    CERN Document Server

    Lafuerza, Luis F; Edmonds, Bruce; McKane, Alan J

    2016-01-01

    Modellers of complex biological or social systems are often faced with an invidious choice: to use simple models with few mechanisms that can be fully analysed, or to construct complicated models that include all the features which are thought relevant. The former ensures rigour, the latter relevance. We discuss a method that combines these two approaches, beginning with a complex model and then modelling the complicated model with simpler models. The resulting "chain" of models ensures some rigour and relevance. We illustrate this process on a complex model of voting intentions, constructing a reduced model which agrees well with the predictions of the full model. Experiments with variations of the simpler model yield additional insights which are hidden by the complexity of the full model. This approach facilitated collaboration between social scientists and physicists -- the complex model was specified based on the social science literature, and the simpler model constrained to agree (in core aspects) with...

  20. Snow accumulation/melting model (SAMM for integrated use in regional scale landslide early warning systems

    Directory of Open Access Journals (Sweden)

    G. Martelloni

    2013-03-01

    Full Text Available We propose a simple snow accumulation/melting model (SAMM to be applied at regional scale in conjunction with landslide warning systems based on empirical rainfall thresholds. SAMM is based on two modules modelling the snow accumulation and the snowmelt processes. Each module is composed by two equations: a conservation of mass equation is solved to model snowpack thickness and an empirical equation for the snow density. The model depends on 13 empirical parameters, whose optimal values were defined with an optimisation algorithm (simplex flexible using calibration measures of snowpack thickness. From an operational point of view, SAMM uses as input data only temperature and rainfall measurements, bringing about the additional benefit of a relatively easy implementation. After performing a cross validation and a comparison with two simpler temperature index models, we simulated an operational employment in a regional scale landslide early warning system (EWS and we found that the EWS forecasting effectiveness was substantially improved when used in conjunction with SAMM.

  1. Real-time lane departure warning system based on principal component analysis of grayscale distribution and risk evaluation model

    Institute of Scientific and Technical Information of China (English)

    张伟伟; 宋晓琳; 张桂香

    2014-01-01

    A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and then each search bar was tracked using Kalman filter between frames. The lane detection performance was evaluated and demonstrated in ways of receiver operating characteristic, dice similarity coefficient and real-time performance. For lane departure detection, a lane departure risk evaluation model based on lasting time and frequency was effectively executed on the ARM-based platform. Experimental results indicate that the algorithm generates satisfactory lane detection results under different traffic and lighting conditions, and the proposed warning mechanism sends effective warning signals, avoiding most false warning.

  2. An Early Warning Model for EU banks with Detection of the Adverse Selection Effect

    OpenAIRE

    Brossard, Olivier; Frédéric DUCROZET (PSE - Crédit Agricole); Adrian ROCHE (EconomiX - Crédit Agricole)

    2007-01-01

    We estimate an early warning model of banks’ failure using a panel of 82 EU banks observed between 1991 and 2005. We make two contributions to the literature. Firstly, we construct a distance-to-default indicator and test its predictive power. The tests implemented here are very similar to those realized by Gropp, Vesala and Vulpes (2005), but our time dimension is four years longer and we use a more restrictive definition of banks’ “failure”. This first part of the paper establishes the accu...

  3. Surveillance of Dengue Fever Virus: A Review of Epidemiological Models and Early Warning Systems

    Science.gov (United States)

    Racloz, Vanessa; Ramsey, Rebecca; Tong, Shilu; Hu, Wenbiao

    2012-01-01

    Dengue fever affects over a 100 million people annually hence is one of the world's most important vector-borne diseases. The transmission area of this disease continues to expand due to many direct and indirect factors linked to urban sprawl, increased travel and global warming. Current preventative measures include mosquito control programs, yet due to the complex nature of the disease and the increased importation risk along with the lack of efficient prophylactic measures, successful disease control and elimination is not realistic in the foreseeable future. Epidemiological models attempt to predict future outbreaks using information on the risk factors of the disease. Through a systematic literature review, this paper aims at analyzing the different modeling methods and their outputs in terms of acting as an early warning system. We found that many previous studies have not sufficiently accounted for the spatio-temporal features of the disease in the modeling process. Yet with advances in technology, the ability to incorporate such information as well as the socio-environmental aspect allowed for its use as an early warning system, albeit limited geographically to a local scale. PMID:22629476

  4. Development and Operation of Space-Based Disease Early Warning Models

    Science.gov (United States)

    John, M. M.

    2010-12-01

    Millions of people die every year from preventable diseases such as malaria and cholera. Pandemics put the entire world population at risk and have the potential to kill thousands and cripple the global economy. In light of these dangers, it is fortunate that the data and imagery gathered by remote sensing satellites can be used to develop models that predict areas at risk for outbreaks. These warnings can help decision makers to distribute preventative medicine and other forms of aid to save lives. There are already many Earth observing satellites in orbit with the ability to provide data and imagery. Researchers have created a number of models based on this information, and some are being used in real-life situations. These capabilities should be further developed and supported by governments and international organizations to benefit as many people as possible. To understand the benefits and challenges of disease early warning models, it is useful to understand how they are developed. A number of steps must occur for satellite data and imagery to be used to prevent disease outbreaks; each requires a variety of inputs and may include a range of experts and stakeholders. This paper discusses the inputs, outputs, and basic processes involved in each of six main steps to developing models, including: identifying and validating links between a disease and environmental factors, creating and validating a software model to predict outbreaks, transitioning a model to operational use, using a model operationally, and taking action on the data provided by the model. The paper briefly overviews past research regarding the link between remote sensing data and disease, and identifies ongoing research in academic centers around the world. The activities of three currently operational models are discussed, including the U.S. Department of Defense Global Emerging Infections Surveillance and Response System (DoD-GEIS), NASA carries out its Malaria Modeling and Surveillance

  5. 基于BOM的项目看板进度预警模型研究%BOM-based Project Schedule Early-warning Model with Kanban Management

    Institute of Scientific and Technical Information of China (English)

    杜百岗; 郭顺生; 孙利波

    2013-01-01

    针对水泥装备制造企业项目进度难以控制的问题,结合企业实际和BOM(bill of material)的层次,建立了多级看板管理进度预警模型.通过典型工序的看板控制及对工序、部件、产品和项目进度预警策略,实现了进度的分级监控和预警.实际应用表明,该模型能满足对项目进度预警的要求.%A multi-stage kanban management model of project schedule early-warning was developed for the project schedule control difficulty in cement equipment manufacturing enterprise.The classification monitoring and early-warning were realized by kanban control for typical process as well as early-warning strategy for processes,parts,products and project progress,which are based on the level of BOM.The practical application in enterprise was accomplished successfully in demonstrating the effectiveness of the model.

  6. Non-stationary time series modeling on caterpillars pest of palm oil for early warning system

    Science.gov (United States)

    Setiyowati, Susi; Nugraha, Rida F.; Mukhaiyar, Utriweni

    2015-12-01

    The oil palm production has an important role for the plantation and economic sector in Indonesia. One of the important problems in the cultivation of oil palm plantation is pests which causes damage to the quality of fruits. The caterpillar pest which feed palm tree's leaves will cause decline in quality of palm oil production. Early warning system is needed to minimize losses due to this pest. Here, we applied non-stationary time series modeling, especially the family of autoregressive models to predict the number of pests based on its historical data. We realized that there is some uniqueness of these pests data, i.e. the spike value that occur almost periodically. Through some simulations and case study, we obtain that the selection of constant factor has a significance influence to the model so that it can shoot the spikes value precisely.

  7. Modeling the three stages in HIV infection.

    Science.gov (United States)

    Hernandez-Vargas, Esteban A; Middleton, Richard H

    2013-03-07

    A typical HIV infection response consists of three stages: an initial acute infection, a long asymptomatic period and a final increase in viral load with simultaneous collapse in healthy CD4+T cell counts. The majority of existing mathematical models give a good representation of either the first two stages or the last stage of the infection. Using macrophages as a long-term active reservoir, a deterministic model is proposed to explain the three stages of the infection including the progression to AIDS. Simulation results illustrate how chronic infected macrophages can explain the progression to AIDS provoking viral explosion. Further simulation studies suggest that the proposed model retains its key properties even under moderately large parameter variations. This model provides important insights on how macrophages might play a crucial role in the long term behavior of HIV infection. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  8. A hybrid evolutionary data driven model for river water quality early warning.

    Science.gov (United States)

    Burchard-Levine, Alejandra; Liu, Shuming; Vince, Francois; Li, Mingming; Ostfeld, Avi

    2014-10-01

    China's fast pace industrialization and growing population has led to several accidental surface water pollution events in the last decades. The government of China, after the 2005 Songhua River incident, has pushed for the development of early warning systems (EWS) for drinking water source protection. However, there are still many weaknesses in EWS in China such as the lack of pollution monitoring and advanced water quality prediction models. The application of Data Driven Models (DDM) such as Artificial Neural Networks (ANN) has acquired recent attention as an alternative to physical models. For a case study in a south industrial city in China, a DDM based on genetic algorithm (GA) and ANN was tested to increase the response time of the city's EWS. The GA-ANN model was used to predict NH3-N, CODmn and TOC variables at station B 2 h ahead of time while showing the most sensitive input variables available at station A, 12 km upstream. For NH3-N, the most sensitive input variables were TOC, CODmn, TP, NH3-N and Turbidity with model performance giving a mean square error (MSE) of 0.0033, mean percent error (MPE) of 6% and regression (R) of 92%. For COD, the most sensitive input variables were Turbidity and CODmn with model performance giving a MSE of 0.201, MPE of 5% and R of 0.87. For TOC, the most sensitive input variables were Turbidity and CODmn with model performance giving a MSE of 0.101, MPE of 2% and R of 0.94. In addition, the GA-ANN model performed better for 8 h ahead of time. For future studies, the use of a GA-ANN modelling technique can be very useful for water quality prediction in Chinese monitoring stations which already measure and have immediately available water quality data.

  9. Two-Stage Modelling Of Random Phenomena

    Science.gov (United States)

    Barańska, Anna

    2015-12-01

    The main objective of this publication was to present a two-stage algorithm of modelling random phenomena, based on multidimensional function modelling, on the example of modelling the real estate market for the purpose of real estate valuation and estimation of model parameters of foundations vertical displacements. The first stage of the presented algorithm includes a selection of a suitable form of the function model. In the classical algorithms, based on function modelling, prediction of the dependent variable is its value obtained directly from the model. The better the model reflects a relationship between the independent variables and their effect on the dependent variable, the more reliable is the model value. In this paper, an algorithm has been proposed which comprises adjustment of the value obtained from the model with a random correction determined from the residuals of the model for these cases which, in a separate analysis, were considered to be the most similar to the object for which we want to model the dependent variable. The effect of applying the developed quantitative procedures for calculating the corrections and qualitative methods to assess the similarity on the final outcome of the prediction and its accuracy, was examined by statistical methods, mainly using appropriate parametric tests of significance. The idea of the presented algorithm has been designed so as to approximate the value of the dependent variable of the studied phenomenon to its value in reality and, at the same time, to have it "smoothed out" by a well fitted modelling function.

  10. Assessing the performance of regional landslide early warning models: the EDuMaP method

    National Research Council Canada - National Science Library

    M. Calvello; L. Piciullo

    2015-01-01

    The paper proposes the evaluation of the technical performance of a regional landslide early warning system by means of an original approach, called EDuMaP method, comprising three successive steps...

  11. Study of Enterprises Marketing Risk Early Warning System Based on BP Neural Network Model

    Institute of Scientific and Technical Information of China (English)

    ZHOU Mei-hua; WANG Fu-dong; ZHANG Hong-hong

    2006-01-01

    For effectively early warning the marketing risk caused along with the varied environment, a BP neural network method was introduced on the basis of analyzing the shortcomings of the risk early warning method, and combined with the practical conditions of dairy enterprises, the index system caused by the marketing risk was also studied. The principal component method was used for screening the indexes, the grades and critical values of the marketing risk were determined. Through the configuration of BP network, node processing and error analysis, the early warning results of the marketing risk were obtained. The results indicate that BP neural network method can be effectively applied through the function approach in the marketing early warning with incomplete information and complex varied conditions.

  12. Developing models to estimate the benefits from flood warnings: executive summary

    OpenAIRE

    Parker, Dennis J.; Priest, Sally J.; Tapsell, Sue M.; Handmer, John W.; Schildt, Anne

    2008-01-01

    Flood forecasting and warning systems have a significant role to play within integrated flood risk management, either in combination with mobile structural flood defences or as part of an approach which combines a number of non-structural measures. In theory the benefits of flood warnings, in terms of community security, protection of life and flood damage reduction, should be large. The theoretical benefit potential is being driven upwards by important advances in the predictive sciences, an...

  13. Early Warning Signals for Regime Transition in the Stable Boundary Layer: A Model Study

    Science.gov (United States)

    van Hooijdonk, I. G. S.; Moene, A. F.; Scheffer, M.; Clercx, H. J. H.; van de Wiel, B. J. H.

    2017-02-01

    The evening transition is investigated in an idealized model for the nocturnal boundary layer. From earlier studies it is known that the nocturnal boundary layer may manifest itself in two distinct regimes, depending on the ambient synoptic conditions: strong-wind or overcast conditions typically lead to weakly stable, turbulent nights; clear-sky and weak-wind conditions, on the other hand, lead to very stable, weakly turbulent conditions. Previously, the dynamical behaviour near the transition between these regimes was investigated in an idealized setting, relying on Monin-Obukhov (MO) similarity to describe turbulent transport. Here, we investigate a similar set-up, using direct numerical simulation; in contrast to MO-based models, this type of simulation does not need to rely on turbulence closure assumptions. We show that previous predictions are verified, but now independent of turbulence parametrizations. Also, it appears that a regime shift to the very stable state is signaled in advance by specific changes in the dynamics of the turbulent boundary layer. Here, we show how these changes may be used to infer a quantitative estimate of the transition point from the weakly stable boundary layer to the very stable boundary layer. In addition, it is shown that the idealized, nocturnal boundary-layer system shares important similarities with generic non-linear dynamical systems that exhibit critical transitions. Therefore, the presence of other, generic early warning signals is tested as well. Indeed, indications are found that such signals are present in stably stratified turbulent flows.

  14. Modeling earthquake indexes derived from the earthquake warning system upon the planet earth

    Science.gov (United States)

    Li, Yong

    2010-12-01

    By studying the correlation between historical earthquake data and the distributional characteristics of parameters of solid earth tides in the earthquake epicenter, we are able to design a forecasting function of earthquake probability. We put forward a design method for the Earthquake Warning System. The model could theoretically simulate and be used to predict the probability of strong earthquakes that could occur anywhere at any time. In addition, the system could also conveniently obtain global or partial Modeling Earthquake Indexes to finally combine the precise pointing prediction and forecast of partial indexes. The literature quotes global data values, provided by NEIC, of 1544 M ⩾ 6.5 earthquakes. It also gives examples of instantaneous earthquake indexes of the whole world and Taiwan Area on 1st January 2010, UT=0:00 and the average earthquake index near the Taiwan Area. According to the 10-year pointing prediction of strong earthquakes in San Francisco, the literature provides the average earthquake index on 24th June 2015 (± 15 days), in its neighborhood.

  15. Modeling earthquake indexes derived from the earthquake warning system upon the planet earth

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    By studying the correlation between historical earthquake data and the distributional characteristics of parameters of solid earth tides in the earthquake epicenter, we are able to design a forecasting function of earthquake probability. We put forward a design method for the Earthquake Warning System. The model could theoretically simulate and be used to predict the probability of strong earthquakes that could occur anywhere at any time. In addition, the system could also conveniently obtain global or partial Modeling Earthquake Indexes to finally combine the precise pointing prediction and forecast of partial indexes. The literature quotes global data values, provided by NEIC, of 1544 M ≥ 6.5 earthquakes. It also gives examples of instantaneous earthquake indexes of the whole world and Taiwan Area on 1st January 2010, UT=0:00 and the average earthquake index near the Taiwan Area. According to the 10-year pointing prediction of strong earthquakes in San Francisco, the literature provides the average earthquake index on 24th June 2015 (± 15 days), in its neighborhood.

  16. [An early warning method of cucumber downy mildew in solar greenhouse based on canopy temperature and humidity modeling].

    Science.gov (United States)

    Wang, Hui; Li, Mei-lan; Xu, Jian-ping; Chen, Mei-xiang; Li, Wen-yong; Li, Ming

    2015-10-01

    The greenhouse environmental parameters can be used to establish greenhouse nirco-climate model, which can combine with disease model for early warning, with aim of ecological controlling diseases to reduce pesticide usage, and protecting greenhouse ecological environment to ensure the agricultural product quality safety. Greenhouse canopy leaf temperature and air relative humidity, models were established using energy balance and moisture balance principle inside the greenhouse. The leaf temperature model considered radiation heat transfer between the greenhouse crops, wall, soil and cover, plus the heat exchange caused by indoor net radiation and crop transpiration. Furthermore, the water dynamic balance in the greenhouse including leaf transpiration, soil evaporation, cover and leaf water vapor condensation, was considered to develop a relative humidity model. The primary infection and latent period warning models for cucumber downy mildew (Pseudoperonospora cubensis) were validated using the results of the leaf temperature and relative humidity model, and then the estimated disease occurrence date of cucumber downy mildew was compared with actual disease occurrence date of field observation. Finally, the results were verified by the measured temperature and humidity data of September and October, 2014. The results showed that the root mean square deviations (RMSDs) of the measured and estimated leaf temperature were 0.016 and 0.024 °C, and the RMSDs of the measured and estimated air relative humidity were 0.15% and 0.13%, respectively. Combining the result of estimated temperature and humidity models, a cucumber disease early warning system was established to forecast the date of disease occurrence, which met with the real date. Thus, this work could provide the micro-environment data for the early warning system of cucumber diseases in solar greenhouses.

  17. Modelling of tidally affected river reaches with data assimilation for flood warning purposes: An example on the River Dee, UK

    Science.gov (United States)

    Smith, P. J.; Beven, K.; Horsburgh, K.; Cullen, J.

    2012-04-01

    On rivers where the flow regime is influenced by a tidal signal the provision of accurate forecasts requires the careful coupling of predictive models for both the tidal signal and the rainfall driven river system. This paper discusses such a coupled modelling system constructed for the River Dee (UK). A series of parsimonious, physically interpretable time series models are used to represent the dynamics of the river water level at several gauging sites on the flood plain. These gauges are used operationally to help in determining the issuing of flood warnings. The simplified models are coupled and cast into a state space form. The assimilation of the observed water levels at the gauge sites to inform future forecasts is then a non-linear filter a solution to which is readily approximated. Assessment of the model forecasts against the observed data is carried out using a number of existing metrics. These suggest the model forecasts are a useful guide to the future water level. The representation of the forecast and its uncertainty to the operational staff is considered. A prototype of the sequential decision making process; based on the relative cost of 'true' or 'false' warnings; and designed to help guide the catchment manager in issuing warnings is presented.

  18. A spatial Bayesian network model to assess the benefits of early warning for urban flood risk to people

    Directory of Open Access Journals (Sweden)

    S. Balbi

    2015-10-01

    Full Text Available This article presents a novel methodology to assess flood risk to people by integrating people's vulnerability and ability to cushion hazards through coping and adapting. The proposed approach extends traditional risk assessments beyond material damages; complements quantitative and semi-quantitative data with subjective and local knowledge, improving the use of commonly available information; produces estimates of model uncertainty by providing probability distributions for all of its outputs. Flood risk to people is modeled using a spatially explicit Bayesian network model calibrated on expert opinion. Risk is assessed in terms of: (1 likelihood of non-fatal physical injury; (2 likelihood of post-traumatic stress disorder; (3 likelihood of death. The study area covers the lower part of the Sihl valley (Switzerland including the city of Zurich. The model is used to estimate the benefits of improving an existing Early Warning System, taking into account the reliability, lead-time and scope (i.e. coverage of people reached by the warning. Model results indicate that the potential benefits of an improved early warning in terms of avoided human impacts are particularly relevant in case of a major flood event: about 75 % of fatalities, 25 % of injuries and 18 % of post-traumatic stress disorders could be avoided.

  19. A spatial Bayesian network model to assess the benefits of early warning for urban flood risk to people

    Science.gov (United States)

    Balbi, Stefano; Villa, Ferdinando; Mojtahed, Vahid; Hegetschweiler, Karin Tessa; Giupponi, Carlo

    2016-06-01

    This article presents a novel methodology to assess flood risk to people by integrating people's vulnerability and ability to cushion hazards through coping and adapting. The proposed approach extends traditional risk assessments beyond material damages; complements quantitative and semi-quantitative data with subjective and local knowledge, improving the use of commonly available information; and produces estimates of model uncertainty by providing probability distributions for all of its outputs. Flood risk to people is modeled using a spatially explicit Bayesian network model calibrated on expert opinion. Risk is assessed in terms of (1) likelihood of non-fatal physical injury, (2) likelihood of post-traumatic stress disorder and (3) likelihood of death. The study area covers the lower part of the Sihl valley (Switzerland) including the city of Zurich. The model is used to estimate the effect of improving an existing early warning system, taking into account the reliability, lead time and scope (i.e., coverage of people reached by the warning). Model results indicate that the potential benefits of an improved early warning in terms of avoided human impacts are particularly relevant in case of a major flood event.

  20. Drought monitoring and assessment: Remote sensing and modeling approaches for the Famine Early Warning Systems Network

    Science.gov (United States)

    Senay, Gabriel; Velpuri, Naga Manohar; Bohms, Stefanie; Budde, Michael; Young, Claudia; Rowland, James; Verdin, James

    2015-01-01

    Drought monitoring is an essential component of drought risk management. It is usually carried out using drought indices/indicators that are continuous functions of rainfall and other hydrometeorological variables. This chapter presents a few examples of how remote sensing and hydrologic modeling techniques are being used to generate a suite of drought monitoring indicators at dekadal (10-day), monthly, seasonal, and annual time scales for several selected regions around the world. Satellite-based rainfall estimates are being used to produce drought indicators such as standardized precipitation index, dryness indicators, and start of season analysis. The Normalized Difference Vegetation Index is being used to monitor vegetation condition. Several satellite data products are combined using agrohydrologic models to produce multiple short- and long-term indicators of droughts. All the data sets are being produced and updated in near-real time to provide information about the onset, progression, extent, and intensity of drought conditions. The data and products produced are available for download from the Famine Early Warning Systems Network (FEWS NET) data portal at http://earlywarning.usgs.gov. The availability of timely information and products support the decision-making processes in drought-related hazard assessment, monitoring, and management with the FEWS NET. The drought-hazard monitoring approach perfected by the U.S. Geological Survey for FEWS NET through the integration of satellite data and hydrologic modeling can form the basis for similar decision support systems. Such systems can operationally produce reliable and useful regional information that is relevant for local, district-level decision making.

  1. 循环经济发展预警模型体系及其应用%Warning model system of circular economy development and its application

    Institute of Scientific and Technical Information of China (English)

    钱吴永; 党耀国; 熊萍萍; 徐宁

    2011-01-01

    对循环经济发展预警模型体系进行了深入研究,为循环经济预警系统提供了量化模型支撑.构建了循环经济发展预警指标体系,提出了循环经济发展的警度测度模型,利用GM(1,1)模型建立了循环经济发展的警度预测模型,并利用构建的循环经济发展预警模型体系对江苏省循环经济的发展进行预警分析,为政府对循环经发展进行监控提供理论指导.%Circular economy early warning has the functions of correctly evaluating the state of current circular economy development, accurately predicting the future trend of the economy cycle, timely reflecting the control effect on the development of circular economy. Research on the early warning system of circular has important sense, and early warning model of development of circular economy is the core of the circular economy early warning system. This paper deeply studied early warning system for circular economy, providing quantitative model support for early warning system of circular economy. And constructed early warning indicator system of circular economy development, put forwards warning degree measurement model for circular economy, used GM(1,1) model to construct warning degree predict model, and with this model analyzed the development of circular economy of Jiangsu province, providing theoretical guidance for the government to monitor the circular economy.

  2. Time-Limited Psychotherapy: An Interactional Stage Model.

    Science.gov (United States)

    Tracey, Terence J.

    One model of successful time-limited psychotherapy characterizes the therapy as a movement through three interactional stages: the early rapport attainment stage, the middle conflict stage, and the final resolution stage. According to this model, these stages are indicated by the relative presence of communicational harmony. To examine the…

  3. Ocean modelling and Early-Warning System for the Gulf of Thailand

    Science.gov (United States)

    de Lima Rego, Joao; Yan, Kun; Sisomphon, Piyamarn; Thanathanphon, Watin; Twigt, Daniel; Irazoqui Apecechea, Maialen

    2017-04-01

    Storm surges associated with severe tropical cyclones are among the most hazardous and damaging natural disasters to coastal areas. The Gulf of Thailand (GoT) has been periodically affected by typhoon induced storm surges in the past (e.g. storm Harriet in 1962, storm Gay in 1989 and storm Linda in 1997). Due to increased touristic / economic development and increased population density in the coastal zone, the combined effect and risk of high water level and increased rainfall / river discharge has dramatically increased and are expected to increase in future due to climate change effects. This presentation describes the development and implementation of the first real-time operational storm surge, wave and wave setup forecasting system in the GoT, a joint applied research initiative by Deltares in The Netherlands and the Hydro and Agro Informatics Institute (HAII) in Thailand. The modelling part includes a new hydrodynamic model to simulate tides and storm surges and two wave models (regional and local). The hydrodynamic model is based on Delft3D Flexible Mesh, capable of simulating water levels and detailed flows. The regional and the recently-developed local wave model are based on the SWAN model, a third-generation wave model. The operational platform is based on Delft-FEWS software, which coordinates all the data inputs, the modelling tasks and the automatic forecast exports including overland inundation in the upper Gulf of Thailand. The main objective of the Gulf of Thailand EWS is to provide daily accurate storm surge, wave and wave setup estimates automatically with various data exports possibilities to support this task. It adds a coastal component to HAII's existing practice of providing daily reports on fluvial flood forecasts, used for decision-support in issuing flood warnings for inland water systems in Thailand. Every day, three-day coastal forecasts are now produced based on the latest regional meteorological predictions. Examples are given to

  4. Early Warning System in ASEAN Countries Using Capital Market Index Return: Modiied Markov Regime Switching Model

    Directory of Open Access Journals (Sweden)

    Imam Wahyudi

    2014-08-01

    Full Text Available Asia's  inancial  crisis  in  July  1997  affects  currency,  capital  market,  and  real  market throughout  Asian  countries.  Countries  in  southeast  region  (ASEAN,  including  Indonesia, Malaysia, Philippines, Singapore, and Thailand, are some of the countries where the crisis hit  the  most.  In  these  countries,  where  inancial  sectors  are  far  more  developed  than  real sectors  and  the  money  market  sectors,  most  of  the  economic  activities  are  conducted  in capital  market.  Movement  in  the  capital  market  could  be  a  proxy  to  describe  the  overall economic  situation  and  therefore  the  prediction  of  it  could  be  an  early  warning  system  of economic crises. This paper tries to investigate movement in ASEAN (Indonesia, Malaysia, Philippines,  Singapore,  and  Thailand  capital  market  to  build  an  early  warning  system from inancial sectors perspective. This paper will be very beneicial for the government to anticipate the forthcoming crisis. The insight of this paper is from Hamilton (1990 model of regime switching process in which he divide the movement of currency into two regimes, describe the switching transition based on Markov process and creates different model for each regimes. Differ from Hamilton, our research focuses on index return instead of currency to  model  the  regime  switching.  This  research  aimed  to  ind  the  probability  of  crisis  in  the future by combining the probability of switching and the probability distribution function of each  regime.  Probability  of  switching  is  estimated  by  categorizing  the  movement  in  index return  into  two  regimes  (negative  return  in  regime  1  and  positive  return  in  regime  2  then measuring  the  proportion  of  switching  to  regime  1  in  t  given  regime

  5. EARLY WARNING MODEL OF NETWORK INTRUSION BASED ON D-S EVIDENCE THEORY

    Institute of Scientific and Technical Information of China (English)

    Tian Junfeng; Zhai Jianqiang; Du Ruizhong; Huang Jiancai

    2005-01-01

    Application of data fusion technique in intrusion detection is the trend of nextgeneration Intrusion Detection System (IDS). In network security, adopting security early warning technique is feasible to effectively defend against attacks and attackers. To do this, correlative information provided by IDS must be gathered and the current intrusion characteristics and situation must be analyzed and estimated. This paper applies D-S evidence theory to distributed intrusion detection system for fusing information from detection centers, making clear intrusion situation, and improving the early warning capability and detection efficiency of the IDS accordingly.

  6. Evaluation of leaf wetness duration models for operational use in strawberry disease-warning systems in four US states

    Science.gov (United States)

    Montone, Verona O.; Fraisse, Clyde W.; Peres, Natalia A.; Sentelhas, Paulo C.; Gleason, Mark; Ellis, Michael; Schnabel, Guido

    2016-11-01

    Leaf wetness duration (LWD) plays a key role in disease development and is often used as an input in disease-warning systems. LWD is often estimated using mathematical models, since measurement by sensors is rarely available and/or reliable. A strawberry disease-warning system called "Strawberry Advisory System" (SAS) is used by growers in Florida, USA, in deciding when to spray their strawberry fields to control anthracnose and Botrytis fruit rot. Currently, SAS is implemented at six locations, where reliable LWD sensors are deployed. A robust LWD model would facilitate SAS expansion from Florida to other regions where reliable LW sensors are not available. The objective of this study was to evaluate the use of mathematical models to estimate LWD and time of spray recommendations in comparison to on site LWD measurements. Specific objectives were to (i) compare model estimated and observed LWD and resulting differences in timing and number of fungicide spray recommendations, (ii) evaluate the effects of weather station sensors precision on LWD models performance, and (iii) compare LWD models performance across four states in the USA. The LWD models evaluated were the classification and regression tree (CART), dew point depression (DPD), number of hours with relative humidity equal or greater than 90 % (NHRH ≥90 %), and Penman-Monteith (P-M). P-M model was expected to have the lowest errors, since it is a physically based and thus portable model. Indeed, the P-M model estimated LWD most accurately (MAE anthracnose and Botrytis fruit rot control and is therefore the model we recommend for expanding the strawberry disease warning beyond Florida, to other locations where weather stations may be deployed with lower precision sensors, and net radiation observations are not available.

  7. Towards the Adriatic meteotsunami early warning system: modelling strategy and validation

    Science.gov (United States)

    Denamiel, Clea; Šepić, Jadranka; Vilibić, Ivica

    2017-04-01

    Destructive meteotsunamis are known to occur along the eastern Adriatic coastal areas and islands (Vilibić and Šepić, 2009). The temporal lag between the offshore generation of meteotsunamis due to specific atmospheric conditions and the arrival of a dangerous nearshore propagating wave at known locations is of the order of tens of minutes to a couple of hours. In order to reduce the coastal risk for the coastal communities, an early warning system must rely on the ability to detect these extreme storms offshore with in-situ measurements and to predict the hydrodynamic response nearshore via numerical models within this short time lag. However, the numerical modelling of meteotsunamis requires both temporal and spatial high-resolution atmospheric and ocean models which are highly demanding concerning time and computer resources. Furthermore, both a multi-model approach and an ensemble modelling strategy should be used to better forecast the distribution of the nearshore impact of meteotsunamis. The modelling strategy used in this study thus rely on the development of an operational atmosphere-ocean model of the Adriatic Sea at 1km spatial resolution based on the state-of-the-art fully coupled COAWST model (Warner et al., 2010). The model allows for generation of meteotsunamis offshore, while various high-resolution (up to 5m) nearshore hydrodynamic models (such as ADCIRC - Luettich and Westerink, 1991; SELFE - Zhang et al., 2008 and GeoClaw - LeVeque, 2012) are setup to properly reproduce meteotsunami dynamics of the entire Croatian coastal areas, which are characterized by a great number of islands, channels and bays. The implementation and validation of each component of this modelling system is first undertaken for the well documented meteotsunami event (Šepić et al., 2016), which was recorded along the Croatian Adriatic coast on the 25th and the 26th of June 2014. The validation of the modelling strategy as well as the model results is presented and

  8. Combining Multiple Rupture Models in Real-Time for Earthquake Early Warning

    Science.gov (United States)

    Minson, S. E.; Wu, S.; Beck, J. L.; Heaton, T. H.

    2015-12-01

    The ShakeAlert earthquake early warning system for the west coast of the United States is designed to combine information from multiple independent earthquake analysis algorithms in order to provide the public with robust predictions of shaking intensity at each user's location before they are affected by strong shaking. The current contributing analyses come from algorithms that determine the origin time, epicenter, and magnitude of an earthquake (On-site, ElarmS, and Virtual Seismologist). A second generation of algorithms will provide seismic line source information (FinDer), as well as geodetically-constrained slip models (BEFORES, GPSlip, G-larmS, G-FAST). These new algorithms will provide more information about the spatial extent of the earthquake rupture and thus improve the quality of the resulting shaking forecasts.Each of the contributing algorithms exploits different features of the observed seismic and geodetic data, and thus each algorithm may perform differently for different data availability and earthquake source characteristics. Thus the ShakeAlert system requires a central mediator, called the Central Decision Module (CDM). The CDM acts to combine disparate earthquake source information into one unified shaking forecast. Here we will present a new design for the CDM that uses a Bayesian framework to combine earthquake reports from multiple analysis algorithms and compares them to observed shaking information in order to both assess the relative plausibility of each earthquake report and to create an improved unified shaking forecast complete with appropriate uncertainties. We will describe how these probabilistic shaking forecasts can be used to provide each user with a personalized decision-making tool that can help decide whether or not to take a protective action (such as opening fire house doors or stopping trains) based on that user's distance to the earthquake, vulnerability to shaking, false alarm tolerance, and time required to act.

  9. A spatiotemporal dengue fever early warning model accounting for nonlinear associations with meteorological factors: a Bayesian maximum entropy approach

    Science.gov (United States)

    Lee, Chieh-Han; Yu, Hwa-Lung; Chien, Lung-Chang

    2014-05-01

    Dengue fever has been identified as one of the most widespread vector-borne diseases in tropical and sub-tropical. In the last decade, dengue is an emerging infectious disease epidemic in Taiwan especially in the southern area where have annually high incidences. For the purpose of disease prevention and control, an early warning system is urgently needed. Previous studies have showed significant relationships between climate variables, in particular, rainfall and temperature, and the temporal epidemic patterns of dengue cases. However, the transmission of the dengue fever is a complex interactive process that mostly understated the composite space-time effects of dengue fever. This study proposes developing a one-week ahead warning system of dengue fever epidemics in the southern Taiwan that considered nonlinear associations between weekly dengue cases and meteorological factors across space and time. The early warning system based on an integration of distributed lag nonlinear model (DLNM) and stochastic Bayesian Maximum Entropy (BME) analysis. The study identified the most significant meteorological measures including weekly minimum temperature and maximum 24-hour rainfall with continuous 15-week lagged time to dengue cases variation under condition of uncertainty. Subsequently, the combination of nonlinear lagged effects of climate variables and space-time dependence function is implemented via a Bayesian framework to predict dengue fever occurrences in the southern Taiwan during 2012. The result shows the early warning system is useful for providing potential outbreak spatio-temporal prediction of dengue fever distribution. In conclusion, the proposed approach can provide a practical disease control tool for environmental regulators seeking more effective strategies for dengue fever prevention.

  10. Spatial Models for Prediction and Early Warning of Aedes aegypti Proliferation from Data on Climate Change and Variability in Cuba.

    Science.gov (United States)

    Ortiz, Paulo L; Rivero, Alina; Linares, Yzenia; Pérez, Alina; Vázquez, Juan R

    2015-04-01

    Climate variability, the primary expression of climate change, is one of the most important environmental problems affecting human health, particularly vector-borne diseases. Despite research efforts worldwide, there are few studies addressing the use of information on climate variability for prevention and early warning of vector-borne infectious diseases. Show the utility of climate information for vector surveillance by developing spatial models using an entomological indicator and information on predicted climate variability in Cuba to provide early warning of danger of increased risk of dengue transmission. An ecological study was carried out using retrospective and prospective analyses of time series combined with spatial statistics. Several entomological and climatic indicators were considered using complex Bultó indices -1 and -2. Moran's I spatial autocorrelation coefficient specified for a matrix of neighbors with a radius of 20 km, was used to identify the spatial structure. Spatial structure simulation was based on simultaneous autoregressive and conditional autoregressive models; agreement between predicted and observed values for number of Aedes aegypti foci was determined by the concordance index Di and skill factor Bi. Spatial and temporal distributions of populations of Aedes aegypti were obtained. Models for describing, simulating and predicting spatial patterns of Aedes aegypti populations associated with climate variability patterns were put forward. The ranges of climate variability affecting Aedes aegypti populations were identified. Forecast maps were generated for the municipal level. Using the Bultó indices of climate variability, it is possible to construct spatial models for predicting increased Aedes aegypti populations in Cuba. At 20 x 20 km resolution, the models are able to provide warning of potential changes in vector populations in rainy and dry seasons and by month, thus demonstrating the usefulness of climate information for

  11. Study on the financial risk warning model of Chinese small and medium enterprises%中国中小型企业财务危机预警模型研究

    Institute of Scientific and Technical Information of China (English)

    王会柠; 张振伟

    2015-01-01

    在复杂多变不可预测的竞争环境下,小型企业需要建立适时的财务风险预警制度。以Altman的 Z 计分模型为理论基础,构建了中小企业财务风险预警模型,并以我国38家电器业上市公司2009年的财务数据进行验证。从我国沪深股市电器业38家样本来看,Altman的Z计分模型,基本上能够反映企业的财务状况,这是一种有效的财务危机预警模型,能发现财务危机的先兆,对中小企业管理者经营管理公司具有一定的指导意义。%The early warning system of financial risk for small and medium enterprises(SMEs)needs to be established under the complex and unpredictable competitive environment.The early warning system of financial risk for SMEs has been modeled based on the theory of Altman Z-score model.In this model,the financial data for 2009 of the38 listed electric companies in China′s Shanghai and Shenzhen stock market has been investigated.This results from the early warning system of financial risk for SMEs based on Altman Z-score model match well with the financial conditions of the enterprises.This model is an effective early-warning model for financial crisis,which can predict the financial crisis for the management of SMEs managers at early stage and guide for future decisions.

  12. 研发型战略联盟风险预警机制研究%An Identification andEarly Warning Model for R&D Alliance Strategies

    Institute of Scientific and Technical Information of China (English)

    胡振华; 张宁辉

    2011-01-01

    , classification, sorting, and optimization of R&D project risks for various projects.From the risk warning perspective, a comprehensive three-dimensional information network is established. Organizational culture refers to risk warning activities related to the formation of standardized risk warning languages and attitudes. R&D risk management process refers to risk warning activities that must meet the R&D project life cycle requirements at different risk warning stages. Our proposed model is based on the entropy theory with the premise of minimizing complexity but with clear responsibilities, rights and interests structured for each subsystem. The model can also maximize the system capacity and the accuracy of information mining. These benefits can improve the degree of system integration with external environment. We have two sources of entropy from within and outside the Union to determine the risk measure. We apply the concept of entropy to improving the accuracy of clear warning signal indicators. The application enables us to derive a complete and accurate prediction model to help decision makers to formulate risk prevention alliance strategies.In conclusion, this paper identifies and highlights the risks of R&D alliance, and describes the risk identification process. We also propose an early warning model of R&D alliance, including the six elements of objective, culture, method, organization, information and process. We also evaluate our proposed model quantitatively based on the entropy theory. The entropy weight is adopted to measure R&D alliance risks. We also use the transmitting entropy to describe the information veracity of the early warning system. Decision-makers of R&D alliances can use the early warning model to improve measurement accuracy.

  13. CyberShake-derived ground-motion prediction models for the Los Angeles region with application to earthquake early warning

    Science.gov (United States)

    Böse, Maren; Graves, Robert W.; Gill, David; Callaghan, Scott; Maechling, Philip J.

    2014-09-01

    Real-time applications such as earthquake early warning (EEW) typically use empirical ground-motion prediction equations (GMPEs) along with event magnitude and source-to-site distances to estimate expected shaking levels. In this simplified approach, effects due to finite-fault geometry, directivity and site and basin response are often generalized, which may lead to a significant under- or overestimation of shaking from large earthquakes (M > 6.5) in some locations. For enhanced site-specific ground-motion predictions considering 3-D wave-propagation effects, we develop support vector regression (SVR) models from the SCEC CyberShake low-frequency (415 000 finite-fault rupture scenarios (6.5 ≤ M ≤ 8.5) for southern California defined in UCERF 2.0. We use CyberShake to demonstrate the application of synthetic waveform data to EEW as a `proof of concept', being aware that these simulations are not yet fully validated and might not appropriately sample the range of rupture uncertainty. Our regression models predict the maximum and the temporal evolution of instrumental intensity (MMI) at 71 selected test sites using only the hypocentre, magnitude and rupture ratio, which characterizes uni- and bilateral rupture propagation. Our regression approach is completely data-driven (where here the CyberShake simulations are considered data) and does not enforce pre-defined functional forms or dependencies among input parameters. The models were established from a subset (˜20 per cent) of CyberShake simulations, but can explain MMI values of all >400 k rupture scenarios with a standard deviation of about 0.4 intensity units. We apply our models to determine threshold magnitudes (and warning times) for various active faults in southern California that earthquakes need to exceed to cause at least `moderate', `strong' or `very strong' shaking in the Los Angeles (LA) basin. These thresholds are used to construct a simple and robust EEW algorithm: to declare a warning, the

  14. [Research of early-warning method for regional groundwater pollution based on risk management].

    Science.gov (United States)

    Bai, Li-Ping; Wang, Ye-Yao; Guo, Yong-Li; Zhou, You-Ya; Liu, Li; Yan, Zeng-Guang; Li, Fa-Sheng

    2014-08-01

    Groundwater is the main source of water supply in China, and China's overall situation of groundwater pollution is not optimistic at present. Groundwater pollution risk evaluation and early-warning are the effective measures to prevent groundwater pollution. At present, research of groundwater early-warning method at home and abroad is still at the exploratory stage, and the sophisticated technology has not been developed for reference. This paper briefly described the data and technological demand of the early-warning method in different scales, and the main factors influencing the early-warning results of groundwater pollution were classified as protection performance of geological medium, characteristics of pollution sources, groundwater dynamics and groundwater value. Then the main early-warning indexes of groundwater pollution were screened to establish the early-warning model of regional or watershed scale by the index overlay method. At last, the established early-warning model was used in Baotou plain, and the different early-warning grades were zoned by the model. The research results could provide scientific support for the local management department to protect the groundwater resources.

  15. A Drought Early Warning System Using System Dynamics Model and Seasonal Climate Forecasts: a case study in Hsinchu, Taiwan.

    Science.gov (United States)

    Tien, Yu-Chuan; Tung, Ching-Ping; Liu, Tzu-Ming; Lin, Chia-Yu

    2016-04-01

    In the last twenty years, Hsinchu, a county of Taiwan, has experienced a tremendous growth in water demand due to the development of Hsinchu Science Park. In order to fulfill the water demand, the government has built the new reservoir, Baoshan second reservoir. However, short term droughts still happen. One of the reasons is that the water level of the reservoirs in Hsinchu cannot be reasonably forecasted, which sometimes even underestimates the severity of drought. The purpose of this study is to build a drought early warning system that projects the water levels of two important reservoirs, Baoshan and Baoshan second reservoir, and also the spatial distribution of water shortagewith the lead time of three months. Furthermore, this study also attempts to assist the government to improve water resources management. Hence, a system dynamics model of Touchien River, which is the most important river for public water supply in Hsinchu, is developed. The model consists of several important subsystems, including two reservoirs, water treatment plants and agricultural irrigation districts. Using the upstream flow generated by seasonal weather forecasting data, the model is able to simulate the storage of the two reservoirs and the distribution of water shortage. Moreover, the model can also provide the information under certain emergency scenarios, such as the accident or failure of a water treatment plant. At last, the performance of the proposed method and the original water resource management method that the government used were also compared. Keyword: Water Resource Management, Hydrology, Seasonal Climate Forecast, Reservoir, Early Warning, Drought

  16. Warning system for hydrogeological hazards in Campania (Southern Italy)

    Science.gov (United States)

    Biafore, Mauro; Cristiano, Luigi; Gentile, Salvatore; Gentilella, Matteo; Giannattasio, Maurizio; Napoli, Francesca

    2010-05-01

    Campania is the Italian region with the highest population density (419 inhabitants/km2). Almost 20% of its territory (13669 km2) is affected by significant hydrogeological hazards, with related loss scenarios in almost 12% of it. The most critical hydrogeological hazard scenarios are those triggered by extreme rainfall events with duration ranging from a few tens of minutes up 72 hours: flood loss scenarios are expected in catchments with spatial extent from a few Km2 up to 5000 km2; shallow landslides and mudflows are also triggered by rainfall events within a broad range of time scales. This study presents a warning system for hydrogeological hazards, which has been operating in Campania since 2005, designed for mitigating losses due to extreme rainfall events. The warning system is structured into two stages: the meteorological forecasting stage and the hydrological monitoring stage. In the first stage, after evaluating rainfall forecasts provided by numerical weather prediction models (with a forecasting time up to 48 hours), warning messages are issued to the local municipalities grouped in 8 warning zones. Critical rainfall events are identified by three different alert levels, according to their forecasted spatial and temporal extents, each corresponding to a category of expected hazard scenarios at regional level. During the second stage, the dynamic evolution of the hydrological events is monitored by a real-time network of river stage and rain gauges, which are employed to compute one or more precursors for each loss scenario. Loss scenarios have been classified according to the temporal and spatial scales of the corresponding precursors, in order to deal with the difficulties related to the occurrence of significantly different hazard scenarios during the same rainfall event. Three threshold values have been identified for each precursor, corresponding to given hazard and alert levels. As a precursor exceeds a threshold value, warning messages are

  17. Flash floods: forecasting and warning

    National Research Council Canada - National Science Library

    Sene, Kevin

    2013-01-01

    ... and levees.The volume discusses the increasing use of meteorological observation and forecasting techniques to extend the lead time available for warning, combined with hydrological models for the river response...

  18. An analysis of financial crisis by an early warning system model: The case of the EU candidate countries

    Directory of Open Access Journals (Sweden)

    Vesna Bucevska

    2011-01-01

    Full Text Available The objective of this paper is to estimate the relative contribution of a wide array of determinants to outbreak of financial crises in the EU candidate countries (Croatia, Macedonia and Turkey and to identify the best-performing early warning indicators of financial crises. We have estimated a binomial logit model of the three EU candidate countries for the period 2005Q1 to 2009Q4 using actual quarterly data. It has been found that the capital account indicators (gross external debt relative to export and the financial sector variables (the domestic loans and the total bank deposits in relation to GDP have the highest contribution of all early warning indicators, which is in line with the previous studies of financial shocks in emerging markets. The obtained empirical results give support to the thesis that financial crises in the EU candidate countries can not be solely explained and predicted by only one group of variables, but by a number of different types of indicators. Based on our empirical findings, the EU candidate countries are strongly suggested to decrease their stock of external debt to GNP and to continually analyze and close monitor the financial deepening processes in their countries.

  19. Research and Application of an Air Quality Early Warning System Based on a Modified Least Squares Support Vector Machine and a Cloud Model

    Science.gov (United States)

    Wang, Jianzhou; Niu, Tong; Wang, Rui

    2017-01-01

    The worsening atmospheric pollution increases the necessity of air quality early warning systems (EWSs). Despite the fact that a massive amount of investigation about EWS in theory and practicality has been conducted by numerous researchers, studies concerning the quantification of uncertain information and comprehensive evaluation are still lacking, which impedes further development in the area. In this paper, firstly a comprehensive warning system is proposed, which consists of two vital indispensable modules, namely effective forecasting and scientific evaluation, respectively. For the forecasting module, a novel hybrid model combining the theory of data preprocessing and numerical optimization is first developed to implement effective forecasting for air pollutant concentration. Especially, in order to further enhance the accuracy and robustness of the warning system, interval forecasting is implemented to quantify the uncertainties generated by forecasts, which can provide significant risk signals by using point forecasting for decision-makers. For the evaluation module, a cloud model, based on probability and fuzzy set theory, is developed to perform comprehensive evaluations of air quality, which can realize the transformation between qualitative concept and quantitative data. To verify the effectiveness and efficiency of the warning system, extensive simulations based on air pollutants data from Dalian in China were effectively implemented, which illustrate that the warning system is not only remarkably high-performance, but also widely applicable. PMID:28257122

  20. Implementation of Malaria Dynamic Models in Municipality Level Early Warning Systems in Colombia. Part I: Description of Study Sites

    Science.gov (United States)

    Ruiz, Daniel; Cerón, Viviana; Molina, Adriana M.; Quiñónes, Martha L.; Jiménez, Mónica M.; Ahumada, Martha; Gutiérrez, Patricia; Osorio, Salua; Mantilla, Gilma; Connor, Stephen J.; Thomson, Madeleine C.

    2014-01-01

    As part of the Integrated National Adaptation Pilot project and the Integrated Surveillance and Control System, the Colombian National Institute of Health is working on the design and implementation of a Malaria Early Warning System framework, supported by seasonal climate forecasting capabilities, weather and environmental monitoring, and malaria statistical and dynamic models. In this report, we provide an overview of the local ecoepidemiologic settings where four malaria process-based mathematical models are currently being implemented at a municipal level. The description includes general characteristics, malaria situation (predominant type of infection, malaria-positive cases data, malaria incidence, and seasonality), entomologic conditions (primary and secondary vectors, mosquito densities, and feeding frequencies), climatic conditions (climatology and long-term trends), key drivers of epidemic outbreaks, and non-climatic factors (populations at risk, control campaigns, and socioeconomic conditions). Selected pilot sites exhibit different ecoepidemiologic settings that must be taken into account in the development of the integrated surveillance and control system. PMID:24891460

  1. Early Warning Model for Energy Price Ratio%能源比价风险预警研究

    Institute of Scientific and Technical Information of China (English)

    何永秀; 董振; 张娜; 朱梦舟; 何海英

    2012-01-01

    伴随着我国经济的高速发展,其能源需求不断增加,能源市场化程度越来越高,所面临的风险也越来越大。而我国目前的能源价格风险预警主要针对单个价格,对能源比价预警的研究很少。首先基于时差相关分析法、Granger因果关系检验法及协整关系检验法,建立了原油、煤炭、天然气、成品油、电力这五种能源的价格风险指标体系;其次从能源价格比价结构的角度,通过计算能源比价的变异系数及波动系数遴选了做预警的时间序列;然后基于CGE模型及能源比价的风险分布得出了能源比价的合理范围,并划分了相应的警度区间,提出了能源比价预警响应机制;最后分析了2012年我国能源比价的警度,得出汽油与原油比价、居民天然气与原油比价、工业用电与原油比价、居民用电与原油比价、天然气与煤比价、电与煤比价不合理情况严重;同时,柴油与原油比价存在较大的风险,需要重点关注。%With the rapid economic development in China,energy demand increases greatly and energy becomes more marketized and its risks grows.At present,the early warning for energy price risk focuses on individual energy price, with less attention to price ratio risk.Therefore,based on time difference cross correlation analysis,Granger causality test and co-integration test,this paper firstly constructs the price risk index system for the five energy resources: crude oil,coal,nature gas,product oil and electricity.Secondly,select the time series suitable to perform early warning by calculating the variation coefficient of energy price ratio from the perspective of energy price ratio structure. Thirdly,estimate the reasonable price ratio range based on CGE model and risk distribution,classify the corresponding warning degree and propose the early warning response mechanism.Finally,analyze the warning degree of energy price ratio in 2012,and point out the

  2. Small-scale (flash) flood early warning in the light of operational requirements: opportunities and limits with regard to user demands, driving data, and hydrologic modeling techniques

    Science.gov (United States)

    Philipp, Andy; Kerl, Florian; Büttner, Uwe; Metzkes, Christine; Singer, Thomas; Wagner, Michael; Schütze, Niels

    2016-05-01

    In recent years, the Free State of Saxony (Eastern Germany) was repeatedly hit by both extensive riverine flooding, as well as flash flood events, emerging foremost from convective heavy rainfall. Especially after a couple of small-scale, yet disastrous events in 2010, preconditions, drivers, and methods for deriving flash flood related early warning products are investigated. This is to clarify the feasibility and the limits of envisaged early warning procedures for small catchments, hit by flashy heavy rain events. Early warning about potentially flash flood prone situations (i.e., with a suitable lead time with regard to required reaction-time needs of the stakeholders involved in flood risk management) needs to take into account not only hydrological, but also meteorological, as well as communication issues. Therefore, we propose a threefold methodology to identify potential benefits and limitations in a real-world warning/reaction context. First, the user demands (with respect to desired/required warning products, preparation times, etc.) are investigated. Second, focusing on small catchments of some hundred square kilometers, two quantitative precipitation forecasts are verified. Third, considering the user needs, as well as the input parameter uncertainty (i.e., foremost emerging from an uncertain QPF), a feasible, yet robust hydrological modeling approach is proposed on the basis of pilot studies, employing deterministic, data-driven, and simple scoring methods.

  3. GITEWS -- The German-Indonesian Tsunami Early Warning System

    Science.gov (United States)

    Lauterjung, J.; Rudloff, A.

    2005-12-01

    The aim of this work is the implementation of an effective Tsunami Early Warning System for the Indian Ocean. It is a component part of an Early Warning System that will also be capable of registering other natural disasters such as earthquakes and volcanic eruptions. The system integrates terrestrial observation networks of seismology und geodesy with marine measurements techniques and satellite observations. The required R & D work will be realized within the framework of a stage-plan, which will, within a short time span of 1-3 years, be able to provide effective warning on the one hand and, which will also allow for an integration of technological developments, currently undergoing further research. The initiative is coordinated by the Helmholtz Association of German Research Centres (HGF), represented by the GeoForschungsZentrum Potsdam (GFZ). In view of the geological situation one has to bear in mind that Indonesia especially, due to the fact that the main islands are located next to and above the Sunda seismogenic zone, could most frequently and most intensively in the future be prone to catastrophic Tsunami events. The envisaged Early Warning System for the Indian Ocean consists of different components as broadband seismometers, GPS, tide gauges, ocean-bottom pressure sensors and GPS-Buoys. On the basis of the data and recordings registered a warning can be generated. This presentation gives insight into the creation of the 26 December 2004 Tsunami, introduces the planned technical realization of the Early Warning System, shows first model scenarios and gives an overview of the planned realization of an Early Warning System in the Indian Ocean. http://www.gfz-potsdam.de

  4. A stage-based model of design teaching

    DEFF Research Database (Denmark)

    Beier, Sofie

    2014-01-01

    With a focus on the teaching of design students in higher education, the article will present a teaching approach model that follows the stages of the design process. The model suggests that at the Definition stage, the supervisor can focus on leading the student into a more thorough elaboration...

  5. First steps in incorporating data-driven modelling to flood early warning in Norway's Flood Forecasting Service

    Science.gov (United States)

    Borsányi, Péter; Hamududu, Byman; Wong Kwok, Wai; Magnusson, Jan; Shi, Min

    2016-04-01

    The national Flood Early Warning Services (FEWS) in Norway use time-series of precipitation and temperature data as input to conceptual physically based rainfall-runoff models for forecasts. Runoff is forecasted in selected catchments and the warnings are based on regionalization of these. This concept proved useful in many catchments, however there are some exceptions, where forecasts are of worse quality. To improve this, data-driven modelling (DDM) techniques are sought applied. The first objective of the study is to identify those DDM methods, which are feasible for application and can easily be fit in the present, well-developed procedures of the operational FEWS. Therefore an experiment is conducted, where about thirty years of daily accumulated precipitation and daily mean temperature as input and observed runoff as output data are used. This was repeated from five, regionally and physically different catchments. In each case different DDMs were developed and their simulation results compared to those generated by the operational (conceptual based) models and to the observations. The methods of Artificial Neural Networks, Genetic Programming, Evolutionary Polynomial Regression and Support Vector Machines were used in the experiment. Various combinations of the last, the last two and the last three timesteps (in this case: days) of the data was tested as possible inputs. Forecast quality was described by Absolute Accumulated Error, Root Mean Square Error, Nash-Sutcliff Efficiency, the Ideal Point Error (combination of the previous) as well as by Taylor-diagrams. The first comparisons show promising results, which need to be further examined. The follow-up study will first focus on standardizing and automating the tests on forecast quality to be able to perform the studies on a larger number of datasets, as well as for other forecast periods. We expect the DDM to perform better in cases where conceptual models don't perform well. In these cases the quality

  6. Establishment of turbidity forecasting model and early-warning system for source water turbidity management using back-propagation artificial neural network algorithm and probability analysis.

    Science.gov (United States)

    Yang, Tsung-Ming; Fan, Shu-Kai; Fan, Chihhao; Hsu, Nien-Sheng

    2014-08-01

    The purpose of this study is to establish a turbidity forecasting model as well as an early-warning system for turbidity management using rainfall records as the input variables. The Taipei Water Source Domain was employed as the study area, and ANOVA analysis showed that the accumulative rainfall records of 1-day Ping-lin, 2-day Ping-lin, 2-day Fei-tsui, 2-day Shi-san-gu, 2-day Tai-pin and 2-day Tong-hou were the six most significant parameters for downstream turbidity development. The artificial neural network model was developed and proven capable of predicting the turbidity concentration in the investigated catchment downstream area. The observed and model-calculated turbidity data were applied to developing the turbidity early-warning system. Using a previously determined turbidity as the threshold, the rainfall criterion, above which the downstream turbidity would possibly exceed this respective threshold turbidity, for the investigated rain gauge stations was determined. An exemplary illustration demonstrated the effectiveness of the proposed turbidity early-warning system as a precautionary alarm of possible significant increase of downstream turbidity. This study is the first report of the establishment of the turbidity early-warning system. Hopefully, this system can be applied to source water turbidity forecasting during storm events and provide a useful reference for subsequent adjustment of drinking water treatment operation.

  7. Warning systems and public warning response

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, J.H.

    1993-09-01

    This background paper reviews current knowledge on warning systems and human response to warnings. It expands on an earlier paper prepared for a workshop on the Second Assessment on Natural Hazards, held in Estes Park, Colorado in July 1992. Although it has a North American perspective, many of the lessons learned are universally applicable. The paper addresses warning systems in terms of dissemination and does not cover physical science issues associated with prediction and forecast. Finally, it covers hazards with relatively short lead times -- 48 hours or less. It does not address topics such as long-term forecasts of earthquakes or volcanic eruptions or early famine warning systems.

  8. Performance of Models for Flash Flood Warning and Hazard Assessment: The 2015 Kali Gandaki Landslide Dam Breach in Nepal

    Directory of Open Access Journals (Sweden)

    Jeremy D. Bricker

    2017-02-01

    Full Text Available The 2015 magnitude 7.8 Gorkha earthquake and its aftershocks weakened mountain slopes in Nepal. Co- and postseismic landsliding and the formation of landslide-dammed lakes along steeply dissected valleys were widespread, among them a landslide that dammed the Kali Gandaki River. Overtopping of the landslide dam resulted in a flash flood downstream, though casualties were prevented because of timely evacuation of low-lying areas. We hindcast the flood using the BREACH physically based dam-break model for upstream hydrograph generation, and compared the resulting maximum flow rate with those resulting from various empirical formulas and a simplified hydrograph based on published observations. Subsequent modeling of downstream flood propagation was compromised by a coarse-resolution digital elevation model with several artifacts. Thus, we used a digital-elevation-model preprocessing technique that combined carving and smoothing to derive topographic data. We then applied the 1-dimensional HEC-RAS model for downstream flood routing, and compared it to the 2-dimensional Delft-FLOW model. Simulations were validated using rectified frames of a video recorded by a resident during the flood in the village of Beni, allowing estimation of maximum flow depth and speed. Results show that hydrological smoothing is necessary when using coarse topographic data (such as SRTM or ASTER, as using raw topography underestimates flow depth and speed and overestimates flood wave arrival lag time. Results also show that the 2-dimensional model produces more accurate results than the 1-dimensional model but the 1-dimensional model generates a more conservative result and can be run in a much shorter time. Therefore, a 2-dimensional model is recommended for hazard assessment and planning, whereas a 1-dimensional model would facilitate real-time warning declaration.

  9. STAGES OF A STRATEGIC MANAGEMENT MODEL

    Directory of Open Access Journals (Sweden)

    Mihaela – Lavinia CIOBANICA

    2014-06-01

    Full Text Available In the literature dedicated to strategic management there is no unitary vision of the authors regarding the sequence of actions that give content to the respective process and what their stages are. With all existing differences, the visions of different authors nevertheless observe the unitary logic of developing a series of actions. These actions begin with the competitive environment analysis in which the organization operates and with the establishment of its strategic mission and they end with the performance evaluation after the strategy has been applied and, if appropriate, with the reconsidering of this strategy and the making of the necessary corrections to it. Such a basic structure of the process is adopted in most organizations that practice the strategic management. But noticeable differences appear in the degree of the formalization of the process and in the involvement of different managerial levels in the designing and detailing of its components.

  10. Possibilities Of Opening Up the Stage-Gate Model

    Directory of Open Access Journals (Sweden)

    Biljana Stošić

    2014-12-01

    Full Text Available The paper presents basic elements of the Stage-Gate and Open innovation models, and possible connection of these two, resulting in what is frequently called an “Open Stage-Gate” model. This connection is based on opening up the new product development process and integration of the open innovation principles with the Stage-Gate concept, facilitating the import and export of information and technologies. Having in mind that the Stage Gate has originally been classified as the third generation model of innovation, the paper is dealing with the capabilities for applying the sixth generation Open innovation principles in today’s improved and much more flexible phases and gates of the Stage Gate. Lots of innovative companies are actually using both models in their NPD practice, looking for the most appropriate means of opening up the well-known closed innovation, especially in the domain of ideation through co-creation.

  11. Method to Determine Appropriate Source Models of Large Earthquakes Including Tsunami Earthquakes for Tsunami Early Warning in Central America

    Science.gov (United States)

    Tanioka, Yuichiro; Miranda, Greyving Jose Arguello; Gusman, Aditya Riadi; Fujii, Yushiro

    2017-08-01

    Large earthquakes, such as the Mw 7.7 1992 Nicaragua earthquake, have occurred off the Pacific coasts of El Salvador and Nicaragua in Central America and have generated distractive tsunamis along these coasts. It is necessary to determine appropriate fault models before large tsunamis hit the coast. In this study, first, fault parameters were estimated from the W-phase inversion, and then an appropriate fault model was determined from the fault parameters and scaling relationships with a depth dependent rigidity. The method was tested for four large earthquakes, the 1992 Nicaragua tsunami earthquake (Mw7.7), the 2001 El Salvador earthquake (Mw7.7), the 2004 El Astillero earthquake (Mw7.0), and the 2012 El Salvador-Nicaragua earthquake (Mw7.3), which occurred off El Salvador and Nicaragua in Central America. The tsunami numerical simulations were carried out from the determined fault models. We found that the observed tsunami heights, run-up heights, and inundation areas were reasonably well explained by the computed ones. Therefore, our method for tsunami early warning purpose should work to estimate a fault model which reproduces tsunami heights near the coast of El Salvador and Nicaragua due to large earthquakes in the subduction zone.

  12. Methodology for Developing Hydrological Models Based on an Artificial Neural Network to Establish an Early Warning System in Small Catchments

    Directory of Open Access Journals (Sweden)

    Ivana Sušanj

    2016-01-01

    Full Text Available In some situations, there is no possibility of hazard mitigation, especially if the hazard is induced by water. Thus, it is important to prevent consequences via an early warning system (EWS to announce the possible occurrence of a hazard. The aim and objective of this paper are to investigate the possibility of implementing an EWS in a small-scale catchment and to develop a methodology for developing a hydrological prediction model based on an artificial neural network (ANN as an essential part of the EWS. The methodology is implemented in the case study of the Slani Potok catchment, which is historically recognized as a hazard-prone area, by establishing continuous monitoring of meteorological and hydrological parameters to collect data for the training, validation, and evaluation of the prediction capabilities of the ANN model. The model is validated and evaluated by visual and common calculation approaches and a new evaluation for the assessment. This new evaluation is proposed based on the separation of the observed data into classes based on the mean data value and the percentages of classes above or below the mean data value as well as on the performance of the mean absolute error.

  13. An SIS Epidemic Model with Stage Structure and a Delay

    Institute of Scientific and Technical Information of China (English)

    Yah-ni Xiao; Lan-sun Chen

    2002-01-01

    A disease transmission model of SIS type with stage structure and a delay is formulated. Stability of the disease free equilibrium, and existence, uniqueness, and stability of an endemic equilibrium, are investigated for the model. The stability results are stated in terms of a key threshold parameter. The effects of stage structure and time delay on dynamical behavior of the infectious disease are analyzed. It is shown that stage structure has no effect on the epidemic model and Hopf bifurcation can occur as the time delay increases.

  14. The Sausage Machine: A New Two-Stage Parsing Model.

    Science.gov (United States)

    Frazier, Lyn; Fodor, Janet Dean

    1978-01-01

    The human sentence parsing device assigns phrase structure to sentences in two steps. The first stage parser assigns lexical and phrasal nodes to substrings of words. The second stage parser then adds higher nodes to link these phrasal packages together into a complete phrase marker. This model is compared with others. (Author/RD)

  15. Wind gust warning verification

    Science.gov (United States)

    Primo, Cristina

    2016-07-01

    Operational meteorological centres around the world increasingly include warnings as one of their regular forecast products. Warnings are issued to warn the public about extreme weather situations that might occur leading to damages and losses. In forecasting these extreme events, meteorological centres help their potential users in preventing the damage or losses they might suffer. However, verifying these warnings requires specific methods. This is due not only to the fact that they happen rarely, but also because a new temporal dimension is added when defining a warning, namely the time window of the forecasted event. This paper analyses the issues that might appear when dealing with warning verification. It also proposes some new verification approaches that can be applied to wind warnings. These new techniques are later applied to a real life example, the verification of wind gust warnings at the German Meteorological Centre ("Deutscher Wetterdienst"). Finally, the results obtained from the latter are discussed.

  16. Warning Signs of Bullying

    Science.gov (United States)

    ... to talk to kids about bullying. Respond to Bullying Learn how to respond to bullying . From stopping ... Text Size: A A A Warning Signs for Bullying There are many warning signs that may indicate ...

  17. Construction of an Early Risk Warning Model of Organizational Resilience: An Empirical Study Based on Samples of R&D Teams

    Directory of Open Access Journals (Sweden)

    Si-hua Chen

    2016-01-01

    Full Text Available Facing fierce competition, it is critical for organizations to keep advantages either actively or passively. Organizational resilience is the ability of an organization to anticipate, prepare for, respond to, and adapt to incremental change and sudden disruptions in order to survive and prosper. It is of particular importance for enterprises to apprehend the intensity of organizational resilience and thereby judge their abilities to withstand pressure. By conducting an exploratory factor analysis and a confirmatory factor analysis, this paper clarifies a five-factor model for organizational resilience of R&D teams. Moreover, based on it, this paper applies fuzzy integrated evaluation method to build an early risk warning model for organizational resilience of R&D teams. The application of the model to a company shows that the model can adequately evaluate the intensity of organizational resilience of R&D teams. The results are also supposed to contribute to applied early risk warning theory.

  18. Numerical and experimental modelling of the radial compressor stage

    Science.gov (United States)

    Syka, Tomáš; Matas, Richard; LuÅáček, Ondřej

    2016-06-01

    This article deals with the description of the numerical and experimental model of the new compressor stage designed for process centrifugal compressors. It's the first member of the new stages family developed to achieve the state of the art thermodynamic parameters. This stage (named RTK01) is designed for high flow coefficient with 3D shaped impeller blades. Some interesting findings were gained during its development. The article is focused mainly on some interesting aspects of the development methodology and numerical simulations improvement, not on the specific stage properties. Conditions and experimental equipment, measured results and their comparison with ANSYS CFX and NUMECA FINE/Turbo CFD simulations are described.

  19. Streamlining environmental product declarations: a stage model

    Science.gov (United States)

    Lefebvre, Elisabeth; Lefebvre, Louis A.; Talbot, Stephane; Le Hen, Gael

    2001-02-01

    General public environmental awareness and education is increasing, therefore stimulating the demand for reliable, objective and comparable information about products' environmental performances. The recently published standard series ISO 14040 and ISO 14025 are normalizing the preparation of Environmental Product Declarations (EPDs) containing comprehensive information relevant to a product's environmental impact during its life cycle. So far, only a few environmentally leading manufacturing organizations have experimented the preparation of EPDs (mostly from Europe), demonstrating its great potential as a marketing weapon. However the preparation of EPDs is a complex process, requiring collection and analysis of massive amounts of information coming from disparate sources (suppliers, sub-contractors, etc.). In a foreseeable future, the streamlining of the EPD preparation process will require product manufacturers to adapt their information systems (ERP, MES, SCADA) in order to make them capable of gathering, and transmitting the appropriate environmental information. It also requires strong functional integration all along the product supply chain in order to ensure that all the information is made available in a standardized and timely manner. The goal of the present paper is two fold: first to propose a transitional model towards green supply chain management and EPD preparation; second to identify key technologies and methodologies allowing to streamline the EPD process and subsequently the transition toward sustainable product development

  20. Risk pre-warning of tender evaluation for civil projects:an outlier detection model

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The marking scheme method removes the low scores of the contractor's attributes given by experts when the overall score is calculated, which may result in that a contractor with some latent risks will win the project. In order to remedy the above defect of the marking scheme method, an outlier detection model, which is one mission of knowledge discovery in data, is established on the basis of the sum of similar coefficients. Then, the model is applied to the historical score data of tender evaluation for ci...

  1. A kinetic model for the first stage of pygas upgrading

    Directory of Open Access Journals (Sweden)

    J. L. de Medeiros

    2007-03-01

    Full Text Available Pyrolysis gasoline - PYGAS - is an intermediate boiling product of naphtha steam cracking with a high octane number and high aromatic/unsaturated contents. Due to stabilization concerns, PYGAS must be hydrotreated in two stages. The first stage uses a mild trickle-bed conversion for removing extremely reactive species (styrene, dienes and olefins prior to the more severe second stage where sulfured and remaining olefins are hydrogenated in gas phase. This work addresses the reaction network and two-phase kinetic model for the first stage of PYGAS upgrading. Nonlinear estimation was used for model tuning with kinetic data obtained in bench-scale trickle-bed hydrogenation with a commercial Pd/Al2O3 catalyst. On-line sampling experiments were designed to study the influence of variables - temperature and spatial velocity - on the conversion of styrene, dienes and olefins.

  2. IMPULSIVE VACCINATION OF SIRS EPIDEMIC MODEL WITH STAGE-STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The period of infection is partitioned into the early and later stages according to the development process of infection. The infected individuals in the different stages have the different ability of transmitting disease. The constant recruitment rate and exponential natural death, as well as the disease-related death and pulse vaccination are incorporated into the model. Through the discrete dynamical system determined by the stroboscopic map, we obtain the exact infection-free periodic solution to the sy...

  3. Dynamic Modelling of the Two-stage Gasification Process

    DEFF Research Database (Denmark)

    Gøbel, Benny; Henriksen, Ulrik B.; Houbak, Niels

    1999-01-01

    A two-stage gasification pilot plant was designed and built as a co-operative project between the Technical University of Denmark and the company REKA.A dynamic, mathematical model of the two-stage pilot plant was developed to serve as a tool for optimising the process and the operating conditions...... of the gasification plant.The model consists of modules corresponding to the different elements in the plant. The modules are coupled together through mass and heat conservation.Results from the model are compared with experimental data obtained during steady and unsteady operation of the pilot plant. A good...

  4. Nonequilibrium stage modelling of dividing wall columns and experimental validation

    Science.gov (United States)

    Hiller, Christoph; Buck, Christina; Ehlers, Christoph; Fieg, Georg

    2010-11-01

    Dealing with complex process units like dividing wall columns pushes the focus on the determination of suitable modelling approaches. For this purpose a nonequilibrium stage model is developed. The successful validation is achieved by an experimental investigation of fatty alcohol mixtures under vacuum condition at pilot scale. Aim is the recovery of high purity products. The proposed model predicts the product qualities and temperature profiles very well.

  5. Modelling the initial stage of porous alumina growth during anodization

    Science.gov (United States)

    Aryslanova, E. M.; Alfimov, A. V.; Chivilikhin, S. A.

    2013-05-01

    Artificially on the surface of aluminum there may be build a thick layer of Al2O3, which has a porous structure. In this paper we present a model of growth of porous alumina in the initial stage of anodizing, identifying dependencies anodizing parameters on the rate of growth of the film and the distance between the pores and as a result of the created model equations were found for changes in the disturbance of alumina for the initial stage of anodizing aluminum oxide porous border aluminum-alumina and alumina-electrolyte, with the influence of surface diffusion of aluminum oxide.

  6. Comparing Methodologies for Developing an Early Warning System: Classification and Regression Tree Model versus Logistic Regression. REL 2015-077

    Science.gov (United States)

    Koon, Sharon; Petscher, Yaacov

    2015-01-01

    The purpose of this report was to explicate the use of logistic regression and classification and regression tree (CART) analysis in the development of early warning systems. It was motivated by state education leaders' interest in maintaining high classification accuracy while simultaneously improving practitioner understanding of the rules by…

  7. Urban Flood Warning Systems using Radar Technologies

    Science.gov (United States)

    Fang, N.; Bedient, P. B.

    2013-12-01

    There have been an increasing number of urban areas that rely on weather radars to provide accurate precipitation information for flood warning purposes. As non-structural tools, radar-based flood warning systems can provide accurate and timely warnings to the public and private entities in urban areas that are prone to flash floods. The wider spatial and temporal coverage from radar increases flood warning lead-time when compared to rain and stream gages alone. The Third Generation Rice and Texas Medical Center (TMC) Flood Alert System (FAS3) has been delivering warning information with 2 to 3 hours of lead time and a R2 value of 93% to facility personnel in a readily understood format for more than 50 events in the past 15 years. The current FAS utilizes NEXRAD Level II radar rainfall data coupled with a real-time hydrologic model (RTHEC-1) to deliver warning information. The system has a user-friendly dashboard to provide rainfall maps, Google Maps based inundation maps, hydrologic predictions, and real-time monitoring at the bayou. This paper will evaluate its reliable performance during the recent events occurring in 2012 and 2013 and the development of a similar radar-based flood warning system for the City of Sugar Land, Texas. Having a significant role in the communication of flood information, FAS marks an important step towards the establishment of an operational and reliable flood warning system for flood-prone urban areas.

  8. Topological Modeling of a One Stage Spur Gear Transmission

    Institute of Scientific and Technical Information of China (English)

    MILADI CHAABANE Mariem; PLATEAUX Rgis; CHOLEY Jean-Yves; KARRA Chafik; RIVIERE Alain; HADDAR Mohamed

    2014-01-01

    Finding a basis of unification for the modeling of mechatronic systems is the search subject of several works. This paper is a part of a general research designed to the application of topology as a new approach for the modeling of mechatronic systems. Particularly, the modeling of a one stage spur gear transmission using a topological approach is tackled. This approach is based on the concepts of topological collections and transformations and implemented using the MGS(modeling of general systems) language. The topological collections are used to specify the interconnection laws of the one stage spur gear transmission and the transformations are used to specify the local behavior laws of its different components. In order to validate this approach, simulation results are presented and compared with those obtained with MODELICA language using Dymola solver. Since good results are achieved, this approach might be used as a basis of unification for the modeling of mechatronic systems.

  9. Topological modeling of a one stage spur gear transmission

    Science.gov (United States)

    Miladi Chaabane, Mariem; Plateaux, Régis; Choley, Jean-Yves; Karra, Chafik; Riviere, Alain; Haddar, Mohamed

    2014-09-01

    Finding a basis of unification for the modeling of mechatronic systems is the search subject of several works. This paper is a part of a general research designed to the application of topology as a new approach for the modeling of mechatronic systems. Particularly, the modeling of a one stage spur gear transmission using a topological approach is tackled. This approach is based on the concepts of topological collections and transformations and implemented using the MGS(modeling of general systems) language. The topological collections are used to specify the interconnection laws of the one stage spur gear transmission and the transformations are used to specify the local behavior laws of its different components. In order to validate this approach, simulation results are presented and compared with those obtained with MODELICA language using Dymola solver. Since good results are achieved, this approach might be used as a basis of unification for the modeling of mechatronic systems.

  10. Two-stage local M-estimation of additive models

    Institute of Scientific and Technical Information of China (English)

    JIANG JianCheng; LI JianTao

    2008-01-01

    This paper studies local M-estimation of the nonparametric components of additive models. A two-stage local M-estimation procedure is proposed for estimating the additive components and their derivatives. Under very mild conditions, the proposed estimators of each additive component and its derivative are jointly asymptotically normal and share the same asymptotic distributions as they would be if the other components were known. The established asymptotic results also hold for two particular local M-estimations: the local least squares and least absolute deviation estimations. However,for general two-stage local M-estimation with continuous and nonlinear ψ-functions, its implementation is time-consuming. To reduce the computational burden, one-step approximations to the two-stage local M-estimators are developed. The one-step estimators are shown to achieve the same efficiency as the fully iterative two-stage local M-estimators, which makes the two-stage local M-estimation more feasible in practice. The proposed estimators inherit the advantages and at the same time overcome the disadvantages of the local least-squares based smoothers. In addition, the practical implementation of the proposed estimation is considered in details. Simulations demonstrate the merits of the two-stage local M-estimation, and a real example illustrates the performance of the methodology.

  11. Two-stage local M-estimation of additive models

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper studies local M-estimation of the nonparametric components of additive models.A two-stage local M-estimation procedure is proposed for estimating the additive components and their derivatives.Under very mild conditions,the proposed estimators of each additive component and its derivative are jointly asymptotically normal and share the same asymptotic distributions as they would be if the other components were known.The established asymptotic results also hold for two particular local M-estimations:the local least squares and least absolute deviation estimations.However,for general two-stage local M-estimation with continuous and nonlinear ψ-functions,its implementation is time-consuming.To reduce the computational burden,one-step approximations to the two-stage local M-estimators are developed.The one-step estimators are shown to achieve the same effciency as the fully iterative two-stage local M-estimators,which makes the two-stage local M-estimation more feasible in practice.The proposed estimators inherit the advantages and at the same time overcome the disadvantages of the local least-squares based smoothers.In addition,the practical implementation of the proposed estimation is considered in details.Simulations demonstrate the merits of the two-stage local M-estimation,and a real example illustrates the performance of the methodology.

  12. The protection motivation theory within the stages of the transtheoretical model - stage-specific interplay of variables and prediction of exercise stage transitions.

    Science.gov (United States)

    Lippke, Sonia; Plotnikoff, Ronald C

    2009-05-01

    Two different theories of health behaviour have been chosen with the aim of theory integration: a continuous theory (protection motivation theory, PMT) and a stage model (transtheoretical model, TTM). This is the first study to test whether the stages of the TTM moderate the interrelation of PMT-variables and the mediation of motivation, as well as PMT-variables' interactions in predicting stage transitions. Hypotheses were tested regarding (1) mean patterns, stage pair-comparisons and nonlinear trends using ANOVAs; (2) prediction-patterns for the different stage groups employing multi-group structural equation modelling (MSEM) and nested model analyses; and (3) stage transitions using binary logistic regression analyses. Adults (N=1,602) were assessed over a 6 month period on their physical activity stages, PMT-variables and subsequent behaviour. (1) Particular mean differences and nonlinear trends in all test variables were found. (2) The PMT adequately fitted the five stage groups. The MSEM revealed that covariances within threat appraisal and coping appraisal were invariant and all other constrains were stage-specific, i.e. stage was a moderator. Except for self-efficacy, motivation fully mediated the relationship between the social-cognitive variables and behaviour. (3) Predicting stage transitions with the PMT-variables underscored the importance of self-efficacy. Only when threat appraisal and coping appraisal were high, stage movement was more likely in the preparation stage. Results emphasize stage-specific differences of the PMT mechanisms, and hence, support the stage construct. The findings may guide further theory building and research integrating different theoretical approaches.

  13. Communication of emergency public warnings: A social science perspective and state-of-the-art assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mileti, D.S. (Colorado State Univ., Fort Collins, CO (USA)); Sorensen, J.H. (Oak Ridge National Lab., TN (USA))

    1990-08-01

    More than 200 studies of warning systems and warning response were reviewed for this social science perspective and state-of-the-art assessment of communication of emergency public warnings. The major findings are as follows. First, variations in the nature and content of warnings have a large impact on whether or not the public heeds the warning. Relevant factors include the warning source; warning channel; the consistency, credibility, accuracy, and understandability of the message; and the warning frequency. Second, characteristics of the population receiving the warning affect warning response. These include social characteristics such as gender, ethnicity and age, social setting characteristics such as stage of life or family context, psychological characteristics such as fatalism or risk perception, and knowledge characteristics such as experience or training. Third, many current myths about public response to emergency warning are at odds with knowledge derived from field investigations. Some of these myths include the keep it simple'' notion, the cry wolf'' syndrome, public panic and hysteria, and those concerning public willingness to respond to warnings. Finally, different methods of warning the public are not equally effective at providing an alert and notification in different physical and social settings. Most systems can provide a warning given three or more hours of available warning time. Special systems such as tone-alert radios are needed to provide rapid warning. 235 refs., 8 figs., 2 tabs.

  14. The study on stage financing model of IT project investment.

    Science.gov (United States)

    Chen, Si-hua; Xu, Sheng-hua; Lee, Changhoon; Xiong, Neal N; He, Wei

    2014-01-01

    Stage financing is the basic operation of venture capital investment. In investment, usually venture capitalists use different strategies to obtain the maximum returns. Due to its advantages to reduce the information asymmetry and agency cost, stage financing is widely used by venture capitalists. Although considerable attentions are devoted to stage financing, very little is known about the risk aversion strategies of IT projects. This paper mainly addresses the problem of risk aversion of venture capital investment in IT projects. Based on the analysis of characteristics of venture capital investment of IT projects, this paper introduces a real option pricing model to measure the value brought by the stage financing strategy and design a risk aversion model for IT projects. Because real option pricing method regards investment activity as contingent decision, it helps to make judgment on the management flexibility of IT projects and then make a more reasonable evaluation about the IT programs. Lastly by being applied to a real case, it further illustrates the effectiveness and feasibility of the model.

  15. Thermal properties Forsmark. Modelling stage 2.3 Complementary analysis and verification of the thermal bedrock model, stage 2.

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan; Wrafter, John; Laendell, Maerta (Geo Innova AB (Sweden)); Back, Paer-Erik; Rosen, Lars (Sweco AB (Sweden))

    2008-11-15

    This report present the results of thermal modelling work for the Forsmark area carried out during modelling stage 2.3. The work complements the main modelling efforts carried out during modelling stage 2.2. A revised spatial statistical description of the rock mass thermal conductivity for rock domain RFM045 is the main result of this work. Thermal modelling of domain RFM045 in Forsmark model stage 2.2 gave lower tail percentiles of thermal conductivity that were considered to be conservatively low due to the way amphibolite, the rock type with the lowest thermal conductivity, was modelled. New and previously available borehole data are used as the basis for revised stochastic geological simulations of domain RFM045. By defining two distinct thermal subdomains, these simulations have succeeded in capturing more of the lithological heterogeneity present. The resulting thermal model for rock domain RFM045 is, therefore, considered to be more realistic and reliable than that presented in model stage 2.2. The main conclusions of modelling efforts in model stage 2.3 are: - Thermal modelling indicates a mean thermal conductivity for domain RFM045 at the 5 m scale of 3.56 W/(mK). This is slightly higher than the value of 3.49 W/(mK) derived in model stage 2.2. - The variance decreases and the lower tail percentiles increase as the scale of observation increases from 1 to 5 m. Best estimates of the 0.1 percentile of thermal conductivity for domain RFM045 are 2.24 W/(mK) for the 1 m scale and 2.36 W/(mK) for the 5 m scale. This can be compared with corresponding values for domain RFM029 of 2.30 W/(mK) for the 1 m scale and 2.87 W/(mK)for the 5 m scale. - The reason for the pronounced lower tail in the thermal conductivity distribution for domain RFM045 is the presence of large bodies of the low-conductive amphibolite. - The modelling results for domain RFM029 presented in model stage 2.2 are still applicable. - As temperature increases, the thermal conductivity decreases

  16. Research on early warning of food security using a system dynamics model: evidence from Jiangsu province in China.

    Science.gov (United States)

    Xu, Jianling; Ding, Yi

    2015-01-01

    Analyzing the early warning of food security, this paper sets the self-sufficiency rate as the principal indicator in a standpoint of supplement. It is common to use the quantitative methods to forecast and warning the insecurity. However, this paper considers more about the probable outcome when the government intervenes. By constructing the causal feedbacks among grain supplement, demand, productive input, and the policy factors to simulate the future food security in Jiangsu province, conclusions can be drawn as the following: (1) The situation of food security is insecure if the self-sufficiency rate is under 68.3% according to the development of system inertia. (2) it is difficult to guarantee the food security in Jiangsu just depending on the increase of grain sown area. (3) The valid solution to ensure the food security in Jiangsu is to improve the productivity.

  17. Evaluation of Flood Forecast and Warning in Elbe river basin - Impact of Forecaster's Strategy

    Science.gov (United States)

    Danhelka, Jan; Vlasak, Tomas

    2010-05-01

    model operation, experience and forecasting strategy differs between responsible forecasting offices. Warning is based on model outputs interpretation by hydrologists-forecaster. Warning hit rate reached 0.60 for threshold set to lowest flood stage of which 0.11 was underestimation of flood degree (miss 0.22, false alarm 0.28). Critical success index of model forecast was 0.34, while the same criteria for warning reached 0.55. We assume that the increase accounts not only to change of scale from single forecasting point to region for warning, but partly also to forecaster's added value. There is no official warning strategy preferred in the Czech Republic (f.e. tolerance towards higher false alarm rate). Therefore forecaster decision and personal strategy is of great importance. Results show quite successful warning for 1st flood level exceedance, over-warning for 2nd flood level, but under-warning for 3rd (highest) flood level. That suggests general forecaster's preference of medium level warning (2nd flood level is legally determined to be the start of the flood and flood protection activities). In conclusion human forecaster's experience and analysis skill increases flood warning performance notably. However society preference should be specifically addressed in the warning strategy definition to support forecaster's decision making.

  18. Modeling the superovulation stage in in vitro fertilization.

    Science.gov (United States)

    Yenkie, Kirti M; Diwekar, Urmila M; Bhalerao, Vibha

    2013-11-01

    In vitro fertilization (IVF) is the most common technique in assisted reproductive technology and in most cases the last resort for infertility treatment. It has four basic stages: superovulation, egg retrieval, insemination/fertilization, and embryo transfer. Superovulation is a drug-induced method to enable multiple ovulation per menstrual cycle. The success of IVF majorly depends upon successful superovulation, defined by the number and similar quality of eggs retrieved in a cycle. Modeling the superovulation stage can help in predicting the outcomes of IVF before the cycle is complete. In this paper, we developed a model for superovulation stage. The model is adapted from the theory of batch crystallization. The aim of crystallization is to get maximum crystals of similar size and purity, while superovulation aims at eggs of similar quality and size. The rate of crystallization and superovulation are both dependent on the process conditions and varies with time. The kinetics of follicle growth is modeled as a function of injected hormones and the follicle properties are represented in terms of the moments. The results from the model prediction were verified with the known data from Jijamata Hospital, Nanded, India. The predictions were found to be in agreement with the actual observations.

  19. Application of regional physically-based landslide early warning model: tuning of the input parameters and validation of the results

    Science.gov (United States)

    D'Ambrosio, Michele; Tofani, Veronica; Rossi, Guglielmo; Salvatici, Teresa; Tacconi Stefanelli, Carlo; Rosi, Ascanio; Benedetta Masi, Elena; Pazzi, Veronica; Vannocci, Pietro; Catani, Filippo; Casagli, Nicola

    2017-04-01

    runs in real-time by assimilating weather data and uses Monte Carlo simulation techniques to manage the geotechnical and hydrological input parameters. In this context, an assessment of the factors controlling the geotechnical and hydrological features is crucial in order to understand the occurrence of slope instability mechanisms and to provide reliable forecasting of the hydrogeological hazard occurrence, especially in relation to weather events. In particular, the model and the soil characterization were applied in back analysis, in order to assess the reliability of the model through validation of the results with landslide events that occurred during the period. The validation was performed on four past events of intense rainfall that have affected Valle d'Aosta region between 2008 and 2010 years triggering fast shallows landslides. The simulations show substantial improvement of the reliability of the results compared to the use of literature parameters. A statistical analysis of the HIRESSS outputs in terms of failure probability has been carried out in order to define reliable alert levels for regional landslide early warning systems.

  20. Hydrogeological conceptual model development and numerical modelling using CONNECTFLOW, Forsmark modelling stage 2.3

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven (SF GeoLogic AB, Taeby (Sweden)); Hartley, Lee; Jackson, Peter; Roberts, David (Serco TAP (United Kingdom)); Marsic, Niko (Kemakta Konsult AB, Stockholm (Sweden))

    2008-05-15

    Three versions of a site descriptive model (SDM) have been completed for the Forsmark area. Version 0 established the state of knowledge prior to the start of the site investigation programme. Version 1.1 was essentially a training exercise and was completed during 2004. Version 1.2 was a preliminary site description and concluded the initial site investigation work (ISI) in June 2005. Three modelling stages are planned for the complete site investigation work (CSI). These are labelled stage 2.1, 2.2 and 2.3, respectively. An important component of each of these stages is to address and continuously try to resolve discipline-specific uncertainties of importance for repository engineering and safety assessment. Stage 2.1 included an updated geological model for Forsmark and aimed to provide a feedback from the modelling working group to the site investigation team to enable completion of the site investigation work. Stage 2.2 described the conceptual understanding and the numerical modelling of the bedrock hydrogeology in the Forsmark area based on data freeze 2.2. The present report describes the modelling based on data freeze 2.3, which is the final data freeze in Forsmark. In comparison, data freeze 2.3 is considerably smaller than data freeze 2.2. Therefore, stage 2.3 deals primarily with model confirmation and uncertainty analysis, e.g. verification of important hypotheses made in stage 2.2 and the role of parameter uncertainty in the numerical modelling. On the whole, the work reported here constitutes an addendum to the work reported in stage 2.2. Two changes were made to the CONNECTFLOW code in stage 2.3. These serve to: 1) improve the representation of the hydraulic properties of the regolith, and 2) improve the conditioning of transmissivity of the deformation zones against single-hole hydraulic tests. The changes to the modelling of the regolith were made to improve the consistency with models made with the MIKE SHE code, which involved the introduction

  1. Stochastic stage-structured modeling of the adaptive immune system

    Energy Technology Data Exchange (ETDEWEB)

    Chao, D. L. (Dennis L.); Davenport, M. P. (Miles P.); Forrest, S. (Stephanie); Perelson, Alan S.,

    2003-01-01

    We have constructed a computer model of the cytotoxic T lymphocyte (CTL) response to antigen and the maintenance of immunological memory. Because immune responses often begin with small numbers of cells and there is great variation among individual immune systems, we have chosen to implement a stochastic model that captures the life cycle of T cells more faithfully than deterministic models. Past models of the immune response have been differential equation based, which do not capture stochastic effects, or agent-based, which are computationally expensive. We use a stochastic stage-structured approach that has many of the advantages of agent-based modeling but is more efficient. Our model can provide insights into the effect infections have on the CTL repertoire and the response to subsequent infections.

  2. Modeling heart rate variability including the effect of sleep stages

    Science.gov (United States)

    Soliński, Mateusz; Gierałtowski, Jan; Żebrowski, Jan

    2016-02-01

    We propose a model for heart rate variability (HRV) of a healthy individual during sleep with the assumption that the heart rate variability is predominantly a random process. Autonomic nervous system activity has different properties during different sleep stages, and this affects many physiological systems including the cardiovascular system. Different properties of HRV can be observed during each particular sleep stage. We believe that taking into account the sleep architecture is crucial for modeling the human nighttime HRV. The stochastic model of HRV introduced by Kantelhardt et al. was used as the initial starting point. We studied the statistical properties of sleep in healthy adults, analyzing 30 polysomnographic recordings, which provided realistic information about sleep architecture. Next, we generated synthetic hypnograms and included them in the modeling of nighttime RR interval series. The results of standard HRV linear analysis and of nonlinear analysis (Shannon entropy, Poincaré plots, and multiscale multifractal analysis) show that—in comparison with real data—the HRV signals obtained from our model have very similar properties, in particular including the multifractal characteristics at different time scales. The model described in this paper is discussed in the context of normal sleep. However, its construction is such that it should allow to model heart rate variability in sleep disorders. This possibility is briefly discussed.

  3. Using a landslide inventory from online news to evaluate the performance of warning models for rainfall-induced landslides in Italy

    Science.gov (United States)

    Pecoraro, Gaetano; Calvello, Michele

    2017-04-01

    In Italy rainfall-induced landslides pose a significant and widespread hazard, resulting in a large number of casualties and enormous economic damages. Mitigation of such a diffuse risk cannot be attained with structural measures only. With respect to the risk to life, early warning systems represent a viable and useful tool for landslide risk mitigation over wide areas. Inventories of rainfall-induced landslides are critical to support investigations of where and when landslides have happened and may occur in the future, i.e. to establish reliable correlations between rainfall characteristics and landslide occurrences. In this work a parametric study has been conducted to evaluate the performance of correlation models between rainfall and landslides over the Italian territory using the "FraneItalia" database, an inventory of landslides retrieved from online Italian journalistic news. The information reported for each record of this database always include: the site of occurrence of the landslides, the date of occurrence, the source of the news. Multiple landslides occurring in the same date, within the same province or region, are inventoried together in one single record of the database, in this case also reporting the number of landslides of the event. Each record the database may also include, if the related information is available: hour of occurrence; typology, volume and material of the landslide; activity phase; effects on people, structures, infrastructures, cars or other elements. The database currently contains six complete years of data (2010-2015), including more than 4000 landslide reports, most of them triggered by rainfall. For the aim of this study, different rainfall-landslides correlation models have been tested by analysing the reported landslides, within all the 144 zones identified by the national civil protection for weather-related warnings in Italy, in relation to satellite-based precipitations estimates from the Global Precipitation

  4. Early warning of freshwater salinization due to upward brine displacement by species transport simulations combined with a hydrochemical genesis model

    Science.gov (United States)

    Langer, Maria; Kühn, Michael

    2016-04-01

    Shallow groundwater resources could be possibly affected by intruding brines, which are displaced along hydraulically conductive faults as result of subsurface activities like CO2 injection. To avoid salinization of potable freshwater aquifers an early detection of intruding saline water is necessary, especially in regions where an initial geogenic salinization already exists. Our study is based on work of Tillner et al. [1] and Langer et al. [2] who investigated the influence of permeable fault systems on brine displacement for the prospective storage site Beeskow-Birkholz in the Northeast German Basin. With a 3D regional scale model considering the deep groundwater system, they demonstrated that the existence of hydraulically conductive faults is not necessarily an exclusion criterion for potential injection sites, because salinization of shallower aquifers strongly depends on the effective damage zone volume, the initial salinity distribution and overlying reservoirs [2], while permeability of fault zones does not influence salinization of shallower aquifers significantly [1]. Here we extracted a 2D cross section regarding the upper 220 m of the study area mainly represented by shallow freshwater aquifers, but also considering an initial geogenic salinization [3]. We took flow rates of the intruding brines from the previous studies [2] and implemented species transport simulations with the program code SHEMAT [4]. Results are investigated and interpreted with the hydrochemical genesis model GEBAH [5] which has been already applied as early warning of saltwater intrusions into freshwater aquifers and surface water [6]. GEBAH allows a categorization of groundwater by the ion ratios of the dissolved components and offers a first indicative determination for an existence and the intensity of saline water intrusion in shallow groundwater aquifer, independent of the concentration of the solution. With our model we investigated the migration of saline water through a

  5. A Two-stage Polynomial Method for Spectrum Emissivity Modeling

    OpenAIRE

    Qiu, Qirong; Liu, Shi; Teng, Jing; Yan, Yong

    2015-01-01

    Spectral emissivity is a key in the temperature measurement by radiation methods, but not easy to determine in a combustion environment, due to the interrelated influence of temperature and wave length of the radiation. In multi-wavelength radiation thermometry, knowing the spectral emissivity of the material is a prerequisite. However in many circumstances such a property is a complex function of temperature and wavelength and reliable models are yet to be sought. In this study, a two stages...

  6. Modifications of some simple One-stage Randomized Response Models to Two-stage in complex surveys

    Directory of Open Access Journals (Sweden)

    Mohammad Rafiq

    2016-06-01

    Full Text Available Warner (1965 introduced a Randomized Response Technique (RRT to minimize bias due to non- response or false response. Thereafter, several researchers have made significant contribution in the development and modification of different Randomized Response Models. We have modified a few one-stage Simple Randomized Response Models to two-stage randomized response models in complex surveys and found that our developed models are more efficient.

  7. Geology - Background complementary studies. Forsmark modelling stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Michael B. [Geological Survey of Sweden, Uppsala (Sweden); Skagius, Kristina [Kemakta Konsult AB, Stockholm (Sweden)] (eds.)

    2007-09-15

    During Forsmark model stage 2.2, seven complementary geophysical and geological studies were initiated by the geological modelling team, in direct connection with and as a background support to the deterministic modelling of deformation zones. One of these studies involved a field control on the character of two low magnetic lineaments with NNE and NE trends inside the target volume. The interpretation of these lineaments formed one of the late deliveries to SKB that took place after the data freeze for model stage 2.2 and during the initial stage of the modelling work. Six studies involved a revised processing and analysis of reflection seismic, refraction seismic and selected oriented borehole radar data, all of which had been presented earlier in connection with the site investigation programme. A prime aim of all these studies was to provide a better understanding of the geological significance of indirect geophysical data to the geological modelling team. Such essential interpretative work was lacking in the material acquired in connection with the site investigation programme. The results of these background complementary studies are published together in this report. The titles and authors of the seven background complementary studies are presented below. Summaries of the results of each study, with a focus on the implications for the geological modelling of deformation zones, are presented in the master geological report, SKB-R--07-45. The sections in the master report, where reference is made to each background complementary study and where the summaries are placed, are also provided. The individual reports are listed in the order that they are referred to in the master geological report and as they appear in this report. 1. Scan line fracture mapping and magnetic susceptibility measurements across two low magnetic lineaments with NNE and NE trend, Forsmark. Jesper Petersson, Ulf B. Andersson and Johan Berglund. 2. Integrated interpretation of surface and

  8. Gear Defect Modeling of a Multiple-Stage Gear Train

    Directory of Open Access Journals (Sweden)

    Andrew Sommer

    2011-01-01

    Full Text Available This study demonstrates the transient and steady state dynamic loading on teeth within a two-stage gear transmission arising from backlash and geometric manufacturing errors by utilizing a nonlinear multibody dynamics software model. Backlash between gear teeth which is essential to provide better lubrication on tooth surfaces and to eliminate interference is included as a defect and a necessary part of transmission design. Torsional vibration is shown to cause teeth separation and double-sided impacts in unloaded and lightly loaded gearing drives. Vibration and impact force distinctions between backlash and combinations of transmission errors are demonstrated under different initial velocities and load conditions. The backlash and manufacturing errors in the first stage of the gear train are distinct from those of the second stage. By analyzing the signal at a location between the two stages, the mutually affected impact forces are observed from different gear pairs, a phenomenon not observed from single pair of gears. Frequency analysis shows the appearance of side band modulations as well as harmonics of the gear mesh frequency. A joint time-frequency response analysis during startup illustrates the manner in which contact forces increase during acceleration.

  9. Combustion Model FOr Staged Circulating Fluidized Bed BOiler

    Institute of Scientific and Technical Information of China (English)

    FandJianhua; LuQinggang; 等

    1997-01-01

    A mathematical model for atmospheric staged circulating fluidized bed combustion,which takes fluid dynamics,combustion,heat transfer,pollutants formation and retention,into account was developed in the institute of Engineering Thermophysics(IET)recently.The model of gas solid flow at the bottom of the combustor was treated by the two-phase theory of fluidized bed and in the upper region as a core-annulus flow structure.The chemical species CO,CO2,H2,H2O,CH4,O2 and N2 were considered in the reaction process.The mathematical model consisted of sub-modeles of fluid namics,coal heterogeneous and gas homogeneous chemical reactions.heat transfer,particle fragmentation and attrition,mass and energy balance tec.The developed code was applied to simulate an operating staged circulating fluidized bed combustion boiler of early design and the results were in good agreement with the operating data.The main submodels and simulation results are given in this paoper.

  10. Research on Dynamic Early Warning Model of Oilfield Production%油田生产动态预警模型研究

    Institute of Scientific and Technical Information of China (English)

    李春生; 魏军; 王博; 王素玲

    2013-01-01

    As the development of Daqing oil field in the middle and late stage of oil field production,various profession has accumulated a large amount of valuable data,these data not only reflect the petroleum exploitation development path,but also record the abnormal pro-duction declined in the process of oilfield development,and the take measures to increase production of the abnormal. Based on the sup-port vector machine,dynamic early warning model is established. By finding the historical production data of changes in production,find abnormal alarm formation mode. Based on the real-time monitoring for oil field development data,can judge in advance the abnormal production decline,and take targeted measures to ensure the benign operation of crude oil production. The eighth of Daqing oil field plant history samples are trained and validated,it is proved that the model for oilfield production abnormal condition has a high prediction accu-racy. Experimental results show that the model is effective,and the model is further improved correlation method.%  随着大庆油田的开发进入中后期,油田生产中的各个专业都积累了大量宝贵的专业数据,这些数据不仅反映了石油开采的发展轨迹,并且记录了油田开发过程中出现的产量异常下降情况,以及针对异常所采取的增产措施。文中建立了基于支持向量机的动态预警模型,通过寻找历史生产数据中的变化规律,找到生产异常报警形成模式,通过对油田开发动态数据的实时监测,可以达到提前判断出产量的异常下降,以便及早采取针对性措施,确保原油生产的良性运行。通过对大庆油田第八采油厂的历史样本进行了训练和验证,证明模型对于油田生产中发生的异常情况具有较高的的预测准确性。实验证明模型的有效性,并且提出对模型进一步改进的相关方法。

  11. Geology Forsmark. Site descriptive modelling Forsmark - stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Michael B. [Geological Survey of Sweden, Uppsala (Sweden); Fox, Aaron; La Pointe, Paul [Golder Associates Inc (United States); Simeonov, Assen [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Isaksson, Hans [GeoVista AB, Luleaa (Sweden); Hermanson, Jan; Oehman, Johan [Golder Associates AB, Stockholm (Sweden)

    2007-10-15

    The geological work during stage 2.2 has involved the development of deterministic models for rock domains (RFM) and deformation zones (ZFM), the identification and deterministic modelling of fracture domains (FFM) inside the candidate volume, i.e. the parts of rock domains that are not affected by deformation zones, and the development of statistical models for fractures and minor deformation zones (geological discrete fracture network modelling or geological DFN modelling). The geological DFN model addresses brittle structures at a scale of less than 1 km, which is the lower cut-off in the deterministic modelling of deformation zones. In order to take account of variability in data resolution, deterministic models for rock domains and deformation zones are presented in both regional and local model volumes, while the geological DFN model is valid within specific fracture domains inside the north-western part of the candidate volume, including the target volume. The geological modelling work has evaluated and made use of: A revised bedrock geological map at the ground surface. Geological and geophysical data from 21 cored boreholes and 33 percussion boreholes. Detailed mapping of fractures and rock units along nine excavations or large surface outcrops. Data bearing on the characterisation (including kinematics) of deformation zones. Complementary geochronological and other rock and fracture analytical data. Lineaments identified on the basis of airborne and high-resolution ground magnetic data. A reprocessing of both surface and borehole reflection seismic data. Seismic refraction data. The outputs of the deterministic modelling work are geometric models in RVS format and detailed property tables for rock domains and deformation zones, and a description of fracture domains. The outputs of the geological DFN modelling process are recommended parameters or statistical distributions that describe fracture set orientations, radius sizes, volumetric intensities

  12. Stabilizing effect of cannibalism in a two stages population model.

    Science.gov (United States)

    Rault, Jonathan; Benoît, Eric; Gouzé, Jean-Luc

    2013-03-01

    In this paper we build a prey-predator model with discrete weight structure for the predator. This model will conserve the number of individuals and the biomass and both growth and reproduction of the predator will depend on the food ingested. Moreover the model allows cannibalism which means that the predator can eat the prey but also other predators. We will focus on a simple version with two weight classes or stage (larvae and adults) and present some general mathematical results. In the last part, we will assume that the dynamics of the prey is fast compared to the predator's one to go further in the results and eventually conclude that under some conditions, cannibalism can stabilize the system: more precisely, an unstable equilibrium without cannibalism will become almost globally stable with some cannibalism. Some numerical simulations are done to illustrate this result.

  13. 旅游危机预警的BP神经网络模型及应用%Application of BP Neural Network Model in Tourism Crisis Early Warning System

    Institute of Scientific and Technical Information of China (English)

    王汉斌; 李晓峰

    2012-01-01

    The development of tourism faces many crises, such as war, disease and natural disasters. This thesis analyzed the factors that affect tourism development, selected the early warning indicators which gave tourism the most profound influence, combined with the date sample of related indexes, applied the BP neural network technology and established a warning system based on the BP neural network model. With the neural network toolbox in the MATLAB for early warning simulation experiment and detection, it proved that the model had a good training performance and high early warning accuracy, which is useful for tourism crisis early warning, detection and analysis in China.%从分析影响旅游业发展的因素出发,选择了对旅游业发展影响最大的危机预警指标,并结合相关数据样本,应用BP神经网络技术,研究建立一种基于BP神经网络模型的旅游危机预警系统,借助MATLAB中的神经网络工具箱进行仿真训练和检测,训练结果表明模型性能良好,预警准确率高,能够很好的用来对旅游危机进行预警、检测和分析研究.

  14. Research on Early Warning Model of the Stroke Incidence%脑卒中发病预警模型研究

    Institute of Scientific and Technical Information of China (English)

    夏英

    2012-01-01

    以2012年全国大学生数学建模竞赛c题为背景,对脑卒中住院病例中的高危人群进行了统计分析,用主成分分析法建立高危人群的预警模型,并给出发病率高低判断的程序流程图及一些干预措施.%Based on the 2012 National Undergraduate Mathematical Contest in modeling C ( MCM), the article gives data filtering on stroke impatients in high-risk. The principal component analysis method is used to estab lish early warning model of populations at risk. Program flow diagram to judge the incidence level and some inter vention measures are given.

  15. A Dual-Stage Two-Phase Model of Selective Attention

    Science.gov (United States)

    Hubner, Ronald; Steinhauser, Marco; Lehle, Carola

    2010-01-01

    The dual-stage two-phase (DSTP) model is introduced as a formal and general model of selective attention that includes both an early and a late stage of stimulus selection. Whereas at the early stage information is selected by perceptual filters whose selectivity is relatively limited, at the late stage stimuli are selected more efficiently on a…

  16. Early warning of West Nile virus mosquito vector: climate and land use models successfully explain phenology and abundance of Culex pipiens mosquitoes in north-western Italy.

    Science.gov (United States)

    Rosà, Roberto; Marini, Giovanni; Bolzoni, Luca; Neteler, Markus; Metz, Markus; Delucchi, Luca; Chadwick, Elizabeth A; Balbo, Luca; Mosca, Andrea; Giacobini, Mario; Bertolotti, Luigi; Rizzoli, Annapaola

    2014-06-12

    West Nile Virus (WNV) is an emerging global health threat. Transmission risk is strongly related to the abundance of mosquito vectors, typically Culex pipiens in Europe. Early-warning predictors of mosquito population dynamics would therefore help guide entomological surveillance and thereby facilitate early warnings of transmission risk. We analysed an 11-year time series (2001 to 2011) of Cx. pipiens mosquito captures from the Piedmont region of north-western Italy to determine the principal drivers of mosquito population dynamics. Linear mixed models were implemented to examine the relationship between Cx. pipiens population dynamics and environmental predictors including temperature, precipitation, Normalized Difference Water Index (NDWI) and the proximity of mosquito traps to urban areas and rice fields. Warm temperatures early in the year were associated with an earlier start to the mosquito season and increased season length, and later in the year, with decreased abundance. Early precipitation delayed the start and shortened the length of the mosquito season, but increased total abundance. Conversely, precipitation later in the year was associated with a longer season. Finally, higher NDWI early in the year was associated with an earlier start to the season and increased season length, but was not associated with abundance. Proximity to rice fields predicted higher total abundance when included in some models, but was not a significant predictor of phenology. Proximity to urban areas was not a significant predictor in any of our models. Predicted variations in start of the season and season length ranged from one to three weeks, across the measured range of variables. Predicted mosquito abundance was highly variable, with numbers in excess of 1000 per trap per year when late season temperatures were low (average 21°C) to only 150 when late season temperatures were high (average 30°C). Climate data collected early in the year, in conjunction with local land

  17. Landslide risk mitigation by means of early warning systems

    Science.gov (United States)

    Calvello, Michele

    2017-04-01

    Among the many options available to mitigate landslide risk, early warning systems may be used where, in specific circumstances, the risk to life increases above tolerable levels. A coherent framework to classify and analyse landslide early warning systems (LEWS) is herein presented. Once the objectives of an early warning strategy are defined depending on the scale of analysis and the type of landslides to address, the process of designing and managing a LEWS should synergically employ technical and social skills. A classification scheme for the main components of LEWSs is proposed for weather-induced landslides. The scheme is based on a clear distinction among: i) the landslide model, i.e. a functional relationship between weather characteristics and landslide events considering the geotechnical, geomorphological and hydro-geological characterization of the area as well as an adequate monitoring strategy; ii) the warning model, i.e. the landslide model plus procedures to define the warning events and to issue the warnings; iii) the warning system, i.e. the warning model plus warning dissemination procedures, communication and education tools, strategies for community involvement and emergency plans. Each component of a LEWS is related to a number of actors involved with their deployment, operational activities and management. For instance, communication and education, community involvement and emergency plans are all significantly influenced by people's risk perception and by operational aspects system managers need to address in cooperation with scientists.

  18. The Innovation Research of Financial Early-Warning Index Measurement

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The period economic fluctuation is vital for an enterprise to exist and further develop,it directly affect the enterprise financial health.So,it is significant to build up financial early-warning index and measure the warning condition that the enterprise faces and take the effective measures to eliminate. We criticize Altman's Z calculating model and build up some new indexes for enterprise financial early-warning condition measuring and making sound decision.

  19. 基于AHP和BPNN的海事网格风险预警模型%Maritime grid risk early-warning model based on AHP and BPNN

    Institute of Scientific and Technical Information of China (English)

    胡志武; 吕鑫鑫; 王胜正

    2014-01-01

    To solve the problem that the risk evaluation of present maritime grid management is limited to the meshing process,the single evaluation method and the low reliability,a maritime grid risk early-warning model is established based on Analytic Hierarchy Process (AHP),BackPropagation Neural Net-work (BPNN),and the theories and methods of system engineering and grid management. First,the maritime grid risk influencing factors are analyzed to establish a risk evaluation index system. Second, the risk level of each maritime grid is defined by AHP,and the future periodic grid risk level is predicted by BPNN. Finally,the risk early-warning level of maritime grid is determined by combining the risk eval-uation results of the above two methods. The model increases the reliability and accuracy of maritime grid risk early-warning. It can provide information support for risk control of the maritime department and en-hance the effect of grid management.%为解决现阶段海事网格化管理的风险评价局限于网格划分过程、评价方法单一、可靠性低的问题,以系统工程和网格化管理的理论和方法为基础,基于层次分析法(Analytic Hierarchy Process,AHP)和反向传播神经网络(BackPropagation Neural Network,BPNN),建立海事网格风险预警模型。首先,对海事网格风险影响因素进行分析,建立风险评价指标体系;然后,运用AHP界定各海事网格风险等级,再运用BPNN预测未来周期网格的风险等级;最后,综合上述两种方法的风险评估结果,确立海事网格风险预警等级。模型增加了海事网格风险预警的可靠性和准确性,可为海事部门提供风险控制的信息支撑,提升网格化管理的效果。

  20. Application of Machine Vision to Vehicle Automatic Collision Warning Algorithm

    Institute of Scientific and Technical Information of China (English)

    WANG Jiang-feng; GAO Feng; XU Guo-yan; YAO Sheng-zhuo

    2008-01-01

    Using the new technologies such as information technology, communication technology and electronic control technology, vehicle collision warning system(CWS) can acquire road condition, adjacent vehicle march condition as well as its dynamics performance continuously, then it can forecast the oncoming potential collision and give a warning. Based on the analysis of driver's driving behavior, algorithm's warning norms are determined. Based on warning norms adopting machine vision method, the cooperation collision warning algorithm(CWA) model with multi-input and multi-output is established which is used in supporting vehicle CWS. The CWA is tested using the actual data and the result shows that this algorithm can identify and carry out warning for vehicle collision efficiently, which has important meaning for improving the vehicle travel safety.

  1. Using the life history model to set the stage(s) of growth and senescence in bioarchaeology and paleodemography.

    Science.gov (United States)

    Roksandic, Mirjana; Armstrong, Stephanie D

    2011-07-01

    Paleodemography, the study of demographic parameters of past human populations, relies on assumptions including biological uniformitarianism, stationary populations, and the ability to determine point age estimates from skeletal material. These assumptions have been widely criticized in the literature and various solutions have been proposed. The majority of these solutions rely on statistical modeling, and have not seen widespread application. Most bioarchaeologists recognize that our ability to assess chronological age is inherently limited, and have instead resorted to large, qualitative, age categories. However, there has been little attempt in the literature to systematize and define the stages of development and ageing used in bioarchaeology. We propose that stages should be based in the human life history pattern, and their skeletal markers should have easily defined and clear endpoints. In addition to a standard five-stage developmental model based on the human life history pattern, current among human biologists, we suggest divisions within the adult stage that recognize the specific nature of skeletal samples. We therefore propose the following eight stages recognizable in human skeletal development and senescence: infancy, early childhood, late childhood, adolescence, young adulthood, full adulthood, mature adulthood, and senile adulthood. Striving toward a better prediction of chronological ages will remain important and could eventually help us understand to what extent past societies differed in the timing of these life stages. Furthermore, paleodemographers should try to develop methods that rely on the type of age information accessible from the skeletal material, which uses life stages, rather than point age estimates.

  2. Applying the "Model of recovering alcoholics' behavior stages and goal setting" to nursing practice.

    Science.gov (United States)

    Wing, D M

    1993-08-01

    In 1990, the author developed the Model of Recovering Alcoholics' Behavior Stages and Goal Setting as a result of grounded theory research. The model explains the natural progression of recovery through four behavior stages. Each stage is characterized by specific patient goals. Application of the model provides a framework for nursing care planning that is both stage-focused and patient-centered. In this article, the author discusses nursing intervention in relation to the model.

  3. Mathematical modeling of a single stage ultrasonically assisted distillation process.

    Science.gov (United States)

    Mahdi, Taha; Ahmad, Arshad; Ripin, Adnan; Abdullah, Tuan Amran Tuan; Nasef, Mohamed M; Ali, Mohamad W

    2015-05-01

    The ability of sonication phenomena in facilitating separation of azeotropic mixtures presents a promising approach for the development of more intensified and efficient distillation systems than conventional ones. To expedite the much-needed development, a mathematical model of the system based on conservation principles, vapor-liquid equilibrium and sonochemistry was developed in this study. The model that was founded on a single stage vapor-liquid equilibrium system and enhanced with ultrasonic waves was coded using MATLAB simulator and validated with experimental data for ethanol-ethyl acetate mixture. The effects of both ultrasonic frequency and intensity on the relative volatility and azeotropic point were examined, and the optimal conditions were obtained using genetic algorithm. The experimental data validated the model with a reasonable accuracy. The results of this study revealed that the azeotropic point of the mixture can be totally eliminated with the right combination of sonication parameters and this can be utilized in facilitating design efforts towards establishing a workable ultrasonically intensified distillation system.

  4. Dengue outlook for the World Cup in Brazil: an early warning model framework driven by real-time seasonal climate forecasts.

    Science.gov (United States)

    Lowe, Rachel; Barcellos, Christovam; Coelho, Caio A S; Bailey, Trevor C; Coelho, Giovanini Evelim; Graham, Richard; Jupp, Tim; Ramalho, Walter Massa; Carvalho, Marilia Sá; Stephenson, David B; Rodó, Xavier

    2014-07-01

    With more than a million spectators expected to travel among 12 different cities in Brazil during the football World Cup, June 12-July 13, 2014, the risk of the mosquito-transmitted disease dengue fever is a concern. We addressed the potential for a dengue epidemic during the tournament, using a probabilistic forecast of dengue risk for the 553 microregions of Brazil, with risk level warnings for the 12 cities where matches will be played. We obtained real-time seasonal climate forecasts from several international sources (European Centre for Medium-Range Weather Forecasts [ECMWF], Met Office, Meteo-France and Centro de Previsão de Tempo e Estudos Climáticos [CPTEC]) and the observed dengue epidemiological situation in Brazil at the forecast issue date as provided by the Ministry of Health. Using this information we devised a spatiotemporal hierarchical Bayesian modelling framework that enabled dengue warnings to be made 3 months ahead. By assessing the past performance of the forecasting system using observed dengue incidence rates for June, 2000-2013, we identified optimum trigger alert thresholds for scenarios of medium-risk and high-risk of dengue. Our forecasts for June, 2014, showed that dengue risk was likely to be low in the host cities Brasília, Cuiabá, Curitiba, Porto Alegre, and São Paulo. The risk was medium in Rio de Janeiro, Belo Horizonte, Salvador, and Manaus. High-risk alerts were triggered for the northeastern cities of Recife (p(high)=19%), Fortaleza (p(high)=46%), and Natal (p(high)=48%). For these high-risk areas, particularly Natal, the forecasting system did well for previous years (in June, 2000-13). This timely dengue early warning permits the Ministry of Health and local authorities to implement appropriate, city-specific mitigation and control actions ahead of the World Cup. European Commission's Seventh Framework Research Programme projects DENFREE, EUPORIAS, and SPECS; Conselho Nacional de Desenvolvimento Científico e Tecnol

  5. A Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success

    Science.gov (United States)

    Luong, Ming; Stevens, Jeff

    2015-01-01

    The Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success, a theoretical stages-of-growth model, explains long-term success in IT outsourcing relationships. Research showed the IT outsourcing relationship life cycle consists of four distinct, sequential stages: contract, transition, support, and partnership. The model was…

  6. A stage-based model of manatee population dynamics

    Science.gov (United States)

    Runge, M.C.; Langtimm, C.A.; Kendall, W.L.

    2004-01-01

    A stage-structured population model for the Florida manatee (Trichechus manatus latirostris) was developed that explicitly incorporates uncertainty in parameter estimates. The growth rates calculated with this model reflect the status of the regional populations over the most recent 10-yr period. The Northwest and Upper St. Johns River regions have growth rates (8) of 1.037 (95% interval, 1.016?1.056) and 1.062 (1.037?1.081), respectively. The Southwest region has a growth rate of 0.989 (0.946?1.024), suggesting this population has been declining at about 1.1% per year. The estimated growth rate in the Atlantic region is 1.010 (0.988?1.029), but there is some uncertainty about whether adult survival rates have been constant over the last 10 yr; using the mean survival rates from the most recent 5-yr period, the estimated growth rate in this region is 0.970 (0.938?0.998). Elasticity analysis indicates that the most effective management actions should seek to increase adult survival rates. Decomposition of the uncertainty in the growth rates indicates that uncertainty about population status can best be reduced through increased monitoring of adult survival rate.

  7. CoopEUS EMSO-OOI Case Study: Tsunami Modelling and Early Warning Systems for Near Source Areas (Mediterranean, Juan de Fuca).

    Science.gov (United States)

    Best, M.; Beranzoli, L.; Chierici, F.; Delaney, J. R.; Embriaco, D.; Galbraith, N.; Huber, R.; Orcutt, J. A.; Weller, R. A.

    2014-12-01

    There is a need for tsunami modeling and early warning systems for near-source areas. For example this is a common public safety threat in the Mediterranean and Juan de Fuca/NE Pacific Coast of N.A.; Regions covered by the EMSO and OOI ocean observatories respectively. Through the CoopEUS EU-US cooperation project, a number of environmental research infrastructures have come together to coordinate efforts on environmental challenges; this tsunami case study tackles one such challenge. There is a mutual need of tsunami event field data and modeling to deepen our experience in testing methodology and developing real-time data processing. Tsunami field data are already available for past events, part of this use case compares these for compatibility, gap analysis, and model groundtruthing. It also reviews sensors needed and harmonizes instrument settings. Sensor metadata and registries are compared, harmonized, and aligned. Data policies and access are also compared and assessed for gap analysis. Modelling algorithms are compared and tested against archived and real-time data. This case study will then be extended to other related tsunami data and model sources globally with similar geographic and seismic scenarios (e.g. DONET, ONC).

  8. Model of unplanned smoking initiation of children and adolescents: an integrated stage model of smoking behavior.

    Science.gov (United States)

    Kremers, S P J; Mudde, A N; De Vries, H

    2004-05-01

    Two lines of psychological research have attempted to spell out the stages of adolescent smoking initiation. The first has focused on behavioral stages of smoking initiation, while the second line emphasized motivational stages. A large international sample of European adolescents (N = 10,170, mean age = 13.3 years) was followed longitudinally. Self-reported motivational and behavioral stages of smoking initiation were integrated, leading to the development of the Model of Unplanned Smoking Initiation of Children and Adolescents (MUSICA). The MUSICA postulates that youngsters experiment with smoking while they are in an unmotivated state as regards their plans for smoking regularly in the future. More than 95% of the total population resided in one of the seven stages distinguished by MUSICA. The probability of starting to smoke regularly during the 12 months follow-up period increased with advanced stage assignment at baseline. Unique social cognitive predictors of stage progression from the various stages were identified, but effect sizes of predictors of transitions were small. The integration of motivational and behavioral dimensions improves our understanding of the process of smoking initiation. In contrast to current theories of smoking initiation, adolescent uptake of smoking behavior was found to be an unplanned action.

  9. Perceived Health Benefits and Soy Consumption Behavior: Two-Stage Decision Model Approach

    OpenAIRE

    Moon, Wanki; Balasubramanian, Siva K.; Rimal, Arbindra

    2005-01-01

    A two-stage decision model is developed to assess the effect of perceived soy health benefits on consumers' decisions with respect to soy food. The first stage captures whether or not to consume soy food, while the second stage reflects how often to consume. A conceptual/analytical framework is also employed, combining Lancaster's characteristics model and Fishbein's multi-attribute model. Results show that perceived soy health benefits significantly influence both decision stages. Further, c...

  10. Warning Triggers in Environmental Hazards: Who Should Be Warned to Do What and When?

    Science.gov (United States)

    Cova, Thomas J; Dennison, Philip E; Li, Dapeng; Drews, Frank A; Siebeneck, Laura K; Lindell, Michael K

    2016-07-13

    Determining the most effective public warnings to issue during a hazardous environmental event is a complex problem. Three primary questions need to be answered: Who should take protective action? What is the best action? and When should this action be initiated? Warning triggers provide a proactive means for emergency managers to simultaneously answer these questions by recommending that a target group take a specified protective action if a preset environmental trigger condition occurs (e.g., warn a community to evacuate if a wildfire crosses a proximal ridgeline). Triggers are used to warn the public across a wide variety of environmental hazards, and an improved understanding of their nature and role promises to: (1) advance protective action theory by unifying the natural, built, and social themes in hazards research into one framework, (2) reveal important information about emergency managers' risk perception, situational awareness, and threat assessment regarding threat behavior and public response, and (3) advance spatiotemporal models for representing the geography and timing of disaster warning and response (i.e., a coupled natural-built-social system). We provide an overview and research agenda designed to advance our understanding and modeling of warning triggers.

  11. Three-Month Real-Time Dengue Forecast Models: An Early Warning System for Outbreak Alerts and Policy Decision Support in Singapore

    Science.gov (United States)

    Shi, Yuan; Liu, Xu; Kok, Suet-Yheng; Rajarethinam, Jayanthi; Liang, Shaohong; Yap, Grace; Chong, Chee-Seng; Lee, Kim-Sung; Tan, Sharon S.Y.; Chin, Christopher Kuan Yew; Lo, Andrew; Kong, Waiming; Ng, Lee Ching; Cook, Alex R.

    2015-01-01

    Background: With its tropical rainforest climate, rapid urbanization, and changing demography and ecology, Singapore experiences endemic dengue; the last large outbreak in 2013 culminated in 22,170 cases. In the absence of a vaccine on the market, vector control is the key approach for prevention. Objectives: We sought to forecast the evolution of dengue epidemics in Singapore to provide early warning of outbreaks and to facilitate the public health response to moderate an impending outbreak. Methods: We developed a set of statistical models using least absolute shrinkage and selection operator (LASSO) methods to forecast the weekly incidence of dengue notifications over a 3-month time horizon. This forecasting tool used a variety of data streams and was updated weekly, including recent case data, meteorological data, vector surveillance data, and population-based national statistics. The forecasting methodology was compared with alternative approaches that have been proposed to model dengue case data (seasonal autoregressive integrated moving average and step-down linear regression) by fielding them on the 2013 dengue epidemic, the largest on record in Singapore. Results: Operationally useful forecasts were obtained at a 3-month lag using the LASSO-derived models. Based on the mean average percentage error, the LASSO approach provided more accurate forecasts than the other methods we assessed. We demonstrate its utility in Singapore’s dengue control program by providing a forecast of the 2013 outbreak for advance preparation of outbreak response. Conclusions: Statistical models built using machine learning methods such as LASSO have the potential to markedly improve forecasting techniques for recurrent infectious disease outbreaks such as dengue. Citation: Shi Y, Liu X, Kok SY, Rajarethinam J, Liang S, Yap G, Chong CS, Lee KS, Tan SS, Chin CK, Lo A, Kong W, Ng LC, Cook AR. 2016. Three-month real-time dengue forecast models: an early warning system for outbreak

  12. Prototyping an Early-warning System for Rainfall-triggered Landslides on a Regional Scale Using a Physically-based Model and Remote Sensing Datasets

    Science.gov (United States)

    Liao, Z.; Hong, Y.; Kirschbaum, D. B.; Fukuoka, H.; Sassa, K.; Karnawati, D.; Fathani, F.

    2010-12-01

    Recent advancements in the availability of remotely sensed datasets provide an opportunity to advance the predictability of rainfall-triggered landslides at larger spatial scales. An early-warning system based on a physical landslide model and remote sensing information is used to simulate the dynamical response of the soil water content to the spatiotemporal variability of rainfall in complex terrain. The system utilizes geomorphologic datasets including a 30-meter ASTER DEM, a 1-km downscaled FAO soil map, and satellite-based Tropical Rainfall Measuring Mission (TRMM) precipitation. The applied physical model SLIDE (SLope-Infiltration-Distributed Equilibrium) defines a direct relationship between a factor of safety and the rainfall depth on an infinite slope. This prototype model is applied to a case study in Honduras during Hurricane Mitch in 1998 and a secondary case of typhoon-induced shallow landslides over Java Island, Indonesia. In Honduras, two study areas were selected which cover approximately 1,200 square kilometers and where a high density of shallow landslides occurred. The results were quantitatively evaluated using landslide inventory data compiled by the United States Geological Survey (USGS) following Hurricane Mitch, and show a good agreement between the modeling results and observations. The success rate for accurately estimating slope failure locations reached as high as 78% and 75%, while the error indices were 35% and 49%, respectively for each of the two selected study areas. Advantages and limitations of this application are discussed with respect to future assessment and challenges of performing a slope-stability estimation using coarse data at 1200 square kilometers. In Indonesia, the system has been applied over the whole Java Island. The prototyped early-warning system has been enhanced by integration of a susceptibility mapping and a precipitation forecasting model (i.e. Weather Research Forecast). The performance has been evaluated

  13. An early warning system for flash floods in Egypt

    Science.gov (United States)

    Cools, J.; Abdelkhalek, A.; El Sammany, M.; Fahmi, A. H.; Bauwens, W.; Huygens, M.

    2009-09-01

    This paper describes the development of the Flash Flood Manager, abbreviated as FlaFloM. The Flash Flood Manager is an early warning system for flash floods which is developed under the EU LIFE project FlaFloM. It is applied to Wadi Watier located in the Sinai peninsula (Egypt) and discharges in the Red Sea at the local economic and tourist hub of Nuweiba city. FlaFloM consists of a chain of four modules: 1) Data gathering module, 2) Forecasting module, 3) Decision support module or DSS and 4) Warning module. Each module processes input data and consequently send the output to the following module. In case of a flash flood emergency, the final outcome of FlaFloM is a flood warning which is sent out to decision-makers. The ‘data gathering module’ collects input data from different sources, validates the input, visualise data and exports it to other modules. Input data is provided ideally as water stage (h), discharge (Q) and rainfall (R) through real-time field measurements and external forecasts. This project, however, as occurs in many arid flash flood prone areas, was confronted with a scarcity of data, and insufficient insight in the characteristics that release a flash flood. Hence, discharge and water stage data were not available. Although rainfall measurements are available through classical off line rain gauges, the sparse rain gauges network couldn’t catch the spatial and temporal characteristics of rainfall events. To overcome this bottleneck, we developed rainfall intensity raster maps (mm/hr) with an hourly time step and raster cell of 1*1km. These maps are derived through downscaling from two sources of global instruments: the weather research and forecasting model (WRF) and satellite estimates from the Tropical Rainfall Measuring Mission (TRMM). The ‘forecast module’ comprises three numerical models that, using data from the gathering module performs simulations on command: a rainfall-runoff model, a river flow model, and a flood model. A

  14. Research and Application of a Variety of Meteorology and Environment Monitoring and Early Warning Model about High Voltage Transmission Line’ s Operating Conditions%高压线路运行环境监测预警研究

    Institute of Scientific and Technical Information of China (English)

    杨莉; 赵薇; 沈映泉; 罗学礼; 王森

    2014-01-01

    With the transmission line condition monitoring of the fine level continues to increase,the research on a variety of envi-ronmental information model which is combination of different environmental factors and is established from the perspective of fusion analysis about multiple data is needed� For the Yunnan-specific environmental factors,this paper established fires and ice monito-ring and early warning model based on temperature,humidity,wind speed and other factors� This model monitoring and early warn-ing the high-voltage transmission Yunnan line operating condition� Practical application shows that the early warning model is accu-rately and efficiently,which can effectively cover an iceberg early warning fire and other disasters,in order to protect the safety and stable operation of transmission lines.%介绍从多种数据融合分析的角度建立开展多种环境信息模型的研究�本文针对云南省特有的环境因素,建立了基于温度、湿度、风速等因素的覆冰和山火监测预警模型,对云南省高压输电线路运行工况进行监测预警,实际应用表明预警模型精确有效,能够有效地对覆冰山火等灾害进行预警,从而保障输电线路的安全稳定运行。

  15. 基于黏滑失稳与突变理论的煤与瓦斯突出预警模型%Early-warning model of coal and gas outburst based on the stick-slip and catastrophe theory

    Institute of Scientific and Technical Information of China (English)

    郭德勇; 李佳乃; 王彦凯

    2013-01-01

    在矿井瓦斯地质研究基础上,根据煤与瓦斯突出黏滑机理和突变理论,建立了煤与瓦斯突出黏滑失稳-突变理论预警模型。以瓦斯因素和地质因素为煤与瓦斯突出预警的控制变量,将其归类分化为相应的预警指标,提出了突出危险等级划分指标的界限,利用模糊数学推导出突变模糊隶属度函数,选择对应突变模型计算出突出警情的突变级数。以潞安环能股份有限公司余吾煤业为例对煤与瓦斯突出黏滑失稳-突变预警模型的可行性进行了验证。%According to gas-geological research, an early-warning model of coal and gas outburst was built based on the stick-slip and catastrophe theory. In the model, gas factors and geological factors were considered as control variables of coal and gas outburst early-warning and were classified to the corresponding early warning indexes, then the coal and gas outburst grades of danger were determined and their warning index limits were divided. Fuzzy mathematics was used to deduce the mutation fuzzy membership function, and the catastrophe series, which can reflect the outburst, was worked out by means of choosing the corresponding mutation model. An example of Yuwu Coal Mine of Lu’an Environmental Energy Development Co., Ltd. verified the feasibility of this early-warning model.

  16. A match-mismatch test of a stage model of behaviour change in tobacco smoking

    NARCIS (Netherlands)

    Dijkstra, A; Conijn, B; De Vries, H

    2006-01-01

    Aims An innovation offered by stage models of behaviour change is that of stage-matched interventions. Match-mismatch studies are the primary test of this idea but also the primary test of the validity of stage models. This study aimed at conducting such a test among tobacco smokers using the Social

  17. A match-mismatch test of a stage model of behaviour change in tobacco smoking

    NARCIS (Netherlands)

    Dijkstra, A; Conijn, B; De Vries, H

    2006-01-01

    Aims An innovation offered by stage models of behaviour change is that of stage-matched interventions. Match-mismatch studies are the primary test of this idea but also the primary test of the validity of stage models. This study aimed at conducting such a test among tobacco smokers using the Social

  18. Faculty Development: A Stage Model Matched to Blended Learning Maturation

    Science.gov (United States)

    Fetters, Michael L.; Duby, Tova Garcia

    2011-01-01

    Faculty development programs are critical to the implementation and support of curriculum innovation. In this case study, the authors present lessons learned from ten years of experience in faculty development programs created to support innovation in technology enhanced learning. Stages of curriculum innovation are matched to stages of faculty…

  19. Recasting the warning-response problem

    DEFF Research Database (Denmark)

    Meyer, C.O.; Otto, F.; Brante, J.;

    2010-01-01

    , accepted, prioritized and responded to by policy-makers. This has led to a simplistic understanding of how communicative, cognitive and political processes involving a range of actors can influence both the perception as well as the response to warnings. The paper also criticizes that many normative...... judgments about the desirability of preventive action are suffering from hindsight bias and insufficient attention to balancing problems related to risk substitution, opportunity costs and moral hazard. In response to these deficits, the paper puts forward a modified model of warning as a persuasive process...

  20. Error reduction and representation in stages (ERRIS) in hydrological modelling for ensemble streamflow forecasting

    Science.gov (United States)

    Li, Ming; Wang, Q. J.; Bennett, James C.; Robertson, David E.

    2016-09-01

    This study develops a new error modelling method for ensemble short-term and real-time streamflow forecasting, called error reduction and representation in stages (ERRIS). The novelty of ERRIS is that it does not rely on a single complex error model but runs a sequence of simple error models through four stages. At each stage, an error model attempts to incrementally improve over the previous stage. Stage 1 establishes parameters of a hydrological model and parameters of a transformation function for data normalization, Stage 2 applies a bias correction, Stage 3 applies autoregressive (AR) updating, and Stage 4 applies a Gaussian mixture distribution to represent model residuals. In a case study, we apply ERRIS for one-step-ahead forecasting at a range of catchments. The forecasts at the end of Stage 4 are shown to be much more accurate than at Stage 1 and to be highly reliable in representing forecast uncertainty. Specifically, the forecasts become more accurate by applying the AR updating at Stage 3, and more reliable in uncertainty spread by using a mixture of two Gaussian distributions to represent the residuals at Stage 4. ERRIS can be applied to any existing calibrated hydrological models, including those calibrated to deterministic (e.g. least-squares) objectives.

  1. Optimization of an industrial retrofitted heat exchanger network, using a stage-wise model

    Energy Technology Data Exchange (ETDEWEB)

    Kovac Kralj, Anita [Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova 17, Maribor 2000 (Slovenia)

    2010-12-15

    The heat exchanger network (HEN) can be optimized using the stage-wise model of superstructure representation, as proposed by Yee and Grossmann. This model can be easily solved regarding both trivial problems, and serious and complex new industrial design plants. In this paper, a stage-wise model for new designs is extended for retrofits by using a stage-wise model for a retrofitted HEN. This method using a stage-wise model is very general; it can be used in new designs as well as during existing process integration. The methodology of the stage-wise model for retrofitted HEN can be used to solve HENs easily and well enough, over a short time, and simultaneously. A mathematical model of stage-wise for retrofit HEN can include additional equations and limitations for retrofits. This model was tested by using a retrofitted methanol process generating an additional profit of 189,200 EUR/a. (author)

  2. A new French flash flood warning service

    Directory of Open Access Journals (Sweden)

    de Saint-Aubin Céline

    2016-01-01

    Full Text Available The French State services in charge of flood forecasting supervise about 22,000 km among the 120,000 km of the French rivers within a warning procedure called Vigilance Crues (http://www.vigicrues.gouv.fr. Some recent dramatic flood events on small watershed not covered by Vigilance Crues highlight the need for a new warning procedure to anticipate violent flash floods that regularly affect rapid river-basins. Thus the concept emerged of an automatic warning service specifically dedicated to local crisis managers. This service will be less elaborated than Vigilance Crues, probably with false alarms and missed events sometimes, but it will deliver a first information. The generation of the warning is based on a simple rainfall-runoff hydrological model developed by Irstea on all French rivers, fed with radar-gauge rainfall grids provided by Meteo-France. Every fifteen minutes, the hydrological model estimates the discharges on the rivers eligible to the service and determine if certain thresholds corresponding to a high or very high flood are likely to be exceeded. The last step of the real-time system is to determine which municipalities are concerned with flood risk and send them an automatic warning by voice call, optionally by sms or email. A specific web interface is available for users to monitor the evolution of the flood risk on maps that are updated every 15 minutes. This new flash flood warning service will be operational early 2017 as a free service for about 8,000 French municipalities.

  3. Using an adjusted Serfling regression model to improve the early warning at the arrival of peak timing of influenza in Beijing.

    Directory of Open Access Journals (Sweden)

    Xiaoli Wang

    Full Text Available Serfling-type periodic regression models have been widely used to identify and analyse epidemic of influenza. In these approaches, the baseline is traditionally determined using cleaned historical non-epidemic data. However, we found that the previous exclusion of epidemic seasons was empirical, since year-year variations in the seasonal pattern of activity had been ignored. Therefore, excluding fixed 'epidemic' months did not seem reasonable. We made some adjustments in the rule of epidemic-period removal to avoid potentially subjective definition of the start and end of epidemic periods. We fitted the baseline iteratively. Firstly, we established a Serfling regression model based on the actual observations without any removals. After that, instead of manually excluding a predefined 'epidemic' period (the traditional method, we excluded observations which exceeded a calculated boundary. We then established Serfling regression once more using the cleaned data and excluded observations which exceeded a calculated boundary. We repeated this process until the R2 value stopped to increase. In addition, the definitions of the onset of influenza epidemic were heterogeneous, which might make it impossible to accurately evaluate the performance of alternative approaches. We then used this modified model to detect the peak timing of influenza instead of the onset of epidemic and compared this model with traditional Serfling models using observed weekly case counts of influenza-like illness (ILIs, in terms of sensitivity, specificity and lead time. A better performance was observed. In summary, we provide an adjusted Serfling model which may have improved performance over traditional models in early warning at arrival of peak timing of influenza.

  4. Using an adjusted Serfling regression model to improve the early warning at the arrival of peak timing of influenza in Beijing.

    Science.gov (United States)

    Wang, Xiaoli; Wu, Shuangsheng; MacIntyre, C Raina; Zhang, Hongbin; Shi, Weixian; Peng, Xiaomin; Duan, Wei; Yang, Peng; Zhang, Yi; Wang, Quanyi

    2015-01-01

    Serfling-type periodic regression models have been widely used to identify and analyse epidemic of influenza. In these approaches, the baseline is traditionally determined using cleaned historical non-epidemic data. However, we found that the previous exclusion of epidemic seasons was empirical, since year-year variations in the seasonal pattern of activity had been ignored. Therefore, excluding fixed 'epidemic' months did not seem reasonable. We made some adjustments in the rule of epidemic-period removal to avoid potentially subjective definition of the start and end of epidemic periods. We fitted the baseline iteratively. Firstly, we established a Serfling regression model based on the actual observations without any removals. After that, instead of manually excluding a predefined 'epidemic' period (the traditional method), we excluded observations which exceeded a calculated boundary. We then established Serfling regression once more using the cleaned data and excluded observations which exceeded a calculated boundary. We repeated this process until the R2 value stopped to increase. In addition, the definitions of the onset of influenza epidemic were heterogeneous, which might make it impossible to accurately evaluate the performance of alternative approaches. We then used this modified model to detect the peak timing of influenza instead of the onset of epidemic and compared this model with traditional Serfling models using observed weekly case counts of influenza-like illness (ILIs), in terms of sensitivity, specificity and lead time. A better performance was observed. In summary, we provide an adjusted Serfling model which may have improved performance over traditional models in early warning at arrival of peak timing of influenza.

  5. Development of a Driving Risk Model Based on Speed Choice: A Case Study to Evaluate the Safety Effects of In-Vehicle Traffic Warning Information

    National Research Council Canada - National Science Library

    KIM, Wonchul; ZHANG, Junyi; FUJIWARA, Akimasa

    2016-01-01

    .... Speed data were collected via an on-site driving experiment on the Sanyo Expressway in Hiroshima Prefecture in Japan in 2009 to examine the impact of in-vehicle traffic warning information (IVTWI) on traffic safety...

  6. Three Stage Equilibrium Model for Coal Gasification in Entrained Flow Gasifiers Based on Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    KONG Xiangdong; ZHONG Weimin; DU Wenli; QIAN Feng

    2013-01-01

    A three stage equilibrium model is developed for coal gasification in the Texaco type coal gasifiers based on Aspen Plus to calculate the composition of product gas,carbon conversion,and gasification temperature.The model is divided into three stages including pyrolysis and combustion stage,char gas reaction stage,and gas phase reaction stage.Part of the water produced in the pyrolysis and combustion stage is assumed to be involved in the second stage to react with the unburned carbon.Carbon conversion is then estimated in the second stage by steam participation ratio expressed as a function of temperature.And the gas product compositions are calculated from gas phase reactions in the third stage.The simulation results are consistent with published experimental data.

  7. Development of a flood-warning network and flood-inundation mapping for the Blanchard River in Ottawa, Ohio

    Science.gov (United States)

    Whitehead, Matthew T.

    2011-01-01

    Digital flood-inundation maps of the Blanchard River in Ottawa, Ohio, were created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Department of Agriculture, Natural Resources Conservation Service and the Village of Ottawa, Ohio. The maps, which correspond to water levels (stages) at the USGS streamgage at Ottawa (USGS streamgage site number 04189260), were provided to the National Weather Service (NWS) for incorporation into a Web-based flood-warning Network that can be used in conjunction with NWS flood-forecast data to show areas of predicted flood inundation associated with forecasted flood-peak stages. Flood profiles were computed by means of a step-backwater model calibrated to recent field measurements of streamflow. The step-backwater model was then used to determine water-surface-elevation profiles for 12 flood stages with corresponding streamflows ranging from less than the 2-year and up to nearly the 500-year recurrence-interval flood. The computed flood profiles were used in combination with digital elevation data to delineate flood-inundation areas. Maps of the Village of Ottawa showing flood-inundation areas overlain on digital orthophotographs are presented for the selected floods. As part of this flood-warning network, the USGS upgraded one streamgage and added two new streamgages, one on the Blanchard River and one on Riley Creek, which is tributary to the Blanchard River. The streamgage sites were equipped with both satellite and telephone telemetry. The telephone telemetry provides dual functionality, allowing village officials and the public to monitor current stage conditions and enabling the streamgage to call village officials with automated warnings regarding flood stage and/or predetermined rates of stage increase. Data from the streamgages serve as a flood warning that emergency management personnel can use in conjunction with the flood-inundation maps by to determine a course of action when flooding is imminent.

  8. Research on Multi-Stage Inventory Model by Markov Decision Process

    Science.gov (United States)

    Rong, Ke

    This paper researched multi-stage inventory system and established limited inventory Markov model, on the other hand it induced DP algorithm of limited inventory Markov model. The results proved that the reorder point of multi-stage inventory system can guarantee demand, and also allows the storage costs to a minimum level in accordance with the above model.

  9. A Spatial Correlation Model of Peak Ground Acceleration and Response Spectra Based on Data of the Istanbul Earthquake Rapid Response and Early Warning System

    Science.gov (United States)

    Wagener, Thomas; Goda, Katsuichiro; Erdik, Mustafa; Daniell, James; Wenzel, Friedemann

    2016-04-01

    Ground motion intensity measures such as the peak ground acceleration (PGA) and the pseudo spectral acceleration (PSA) at two sites due to the same seismic event are correlated. The spatial correlation needs to be considered when modelling ground-motion fields for seismic loss assessments, since it can have a significant influence on the statistical moments and probability distribution of aggregated seismic loss of a building portfolio. Empirical models of spatial correlation of ground motion intensity measures exist only for a few seismic regions in the world such as Japan, Taiwan and California, since for this purpose a dense observation network of earthquake ground motion is required. The Istanbul Earthquake Rapid Response and Early Warning System (IERREWS) provides one such dense array with station spacing of typically 2 km in the urban area of Istanbul. Based on the records of eight small to moderate (Mw3.5 - Mw5.1) events, which occurred since 2003 in the Marmara region, we establish a model of intra-event spatial correlation for PGA and PSA up to the natural period of 1.0 s. The results indicate that the correlation coefficients of PGA and short-period PSA decay rapidly with increasing interstation distance, resulting in correlation lengths of approximately 2-3 km, while correlation lengths at longer natural periods (above 0.5 s) exceed 5 km. Finally, we implement the correlation model in a Monte Carlo simulation to evaluate economic loss in Istanbul's district Zeytinburnu due to an Mw7.2 scenario earthquake.

  10. Worm Warning and Optimization of Nonlinear Propagation Model%蠕虫预警及非线性传播模型优化

    Institute of Scientific and Technical Information of China (English)

    佟晓筠; 王翥

    2011-01-01

    At present there are some worm intrusion detection systems which detect network worms only by using worm propagation properties and have high false alarm rate.This paper analyzed worm non-linear propagation models, realized the optimization of worm model, and proposed distributed worm propagation model.Then a distributed worm detection technology was designed according to the distributed worm propagation model.The system uses rule-based detection method to monitor network worms, and the console side manages and coordinates detection work of the client sides.The experimental results show that the technology is a good solution to worm warning and worm detection, which can give an alarm with high detection rate and low false alarm rate.%目前已有一些蠕虫检测系统利用蠕虫传播特性进行检测,误报率高,不能对大范围网络进行检测.为此,首先对蠕虫传播模型进行了分析和优化,提出了新蠕虫分布式传播模型.针对该模型提出了分布式蠕虫检测技术,亦即采用基于规则的检测方法监控网络蠕虫,控制台管理和协调多个检测端的工作.实验结果表明,该方法能够很好地预警蠕虫的传播行为并进行监控和报警,具有高检测率和低误报率.

  11. R0-modeling as a tool for early warning and surveillance of exotic vector borne diseases in Denmark

    DEFF Research Database (Denmark)

    Bødker, Rene

    2011-01-01

    the surveillance on periods and areas with high R0 estimates even if the actual value of these estimates are difficult to interpret. Furthermore running R0 models on historic outbreaks in Europe may be used to fit estimates for R0 for these data. When comparing the model R0 to the observed value of R0 a correction...

  12. R0-modeling as a tool for early warning and surveillance of exotic vector borne diseases in Denmark

    DEFF Research Database (Denmark)

    Bødker, Rene; Kristensen, Birgit; Græsbøll, Kaare;

    with high R0 estimates even if the actual value of these estimates are difficult to interpret. Furthermore running R0 models on historic outbreaks in Europe may be used to fit estimates for R0 for these data. When comparing the model R0 to the observed value of R0 a correction factor is obtained that may...

  13. 49 CFR 234.259 - Warning time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Warning time. 234.259 Section 234.259..., Inspection, and Testing Inspections and Tests § 234.259 Warning time. Each crossing warning system shall be tested for the prescribed warning time at least once every 12 months and when the warning system...

  14. Harmful algal bloom forecast system for SW Ireland. Part II: Are operational oceanographic models useful in a HAB warning system.

    Science.gov (United States)

    Cusack, Caroline; Dabrowski, Tomasz; Lyons, Kieran; Berry, Alan; Westbrook, Guy; Salas, Rafael; Duffy, Conor; Nolan, Glenn; Silke, Joe

    2016-03-01

    This study investigated the application of a three-dimensional physical hydrodynamic model in a harmful algal bloom forecast system for Bantry Bay, southwest Ireland. Modelled oceanographic conditions were studied and used to help understand observed changes in the chemical and biological patterns from the national biotoxins and phytoplankton monitoring program. The study focused on two toxic events in 2013. An upwelling event was predicted by the model prior to the appearance and population increase of potentially toxic diatoms, Pseudo-nitzschia, and associated domoic acid in shellfish. A downwelling episode was provided as a forecast in the model prior to the arrival of a Dinophysis bloom and detection of its associated biotoxins in Bay shellfish. The modelled forecast products developed included expected surface, mid-depth and bottom current pathways at the mouth of the Bay and on the adjacent shelf. The rate and direction of water volume flow at the mouth and mid-bay sections were produced by the model to examine predicted upwelling and downwelling pulses. The model also calculated the evolution of water properties (temperature, salinity and density) with depth along the Bay axis and on the adjacent continental shelf. Direct measurements of water properties at a fixed point, mid-bay, were comparable to model calculations. The operational model for southwest Ireland produces a reliable 3-day physical hydrodynamic forecast of the dominant regional physical processes that result in water exchange events between Bantry Bay and its adjacent shelf. While simulated physical hydrodynamics were provided as a 3-day forecast, the upwelling and downwelling signals from the model, closely linked to toxic HAB episodes, were evident up to 10 days prior to the contamination of shellfish in the Bay.

  15. A Study of 1-N Early Warning Framework Model and Its Application to Flood Control and Disaster Reduction%1?N预警发布架构模型的研究及防洪减灾应用

    Institute of Scientific and Technical Information of China (English)

    左仲元

    2012-01-01

    This paper presents 1-N framework model for early warning of small and medium-sized natural disasters, elaborates on structural features and functions of the model, and analyzes construction of 1-N early warning region, development of early warning system, and model of its application in view of flood control and disaster reduction. The model has achieved excellent disaster allevia- tion efficiency and has been awarded the Hunan Provincial Third Prizes for Progress in Science and Technology in 2011.%提出了用于中小尺度自然灾害预警发布的1-N预警发布架构模型,阐述了模型的结构特点和功能,并从防洪减灾角度出发,分析1-N预警区域的构建、预警系统研制和应用模式。研究成果已在湖南省防汛减灾中应用,取得了较好的减灾效益,同时获得了2011年度湖南省科技进步三等奖。

  16. An experimentally validated simulation model for a four-stage spray dryer

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

    2017-01-01

    is divided into four consecutive stages: a primary spray drying stage, two heated fluid bed stages, and a cooling fluid bed stage. Each of these stages in the model is assumed ideally mixed and the dynamics are described by mass- and energy balances. These balance equations are coupled with constitutive...... equations such as a thermodynamic model, the water evaporation rate, the heat transfer rates, and an equation for the stickiness of the powder (glass transition temperature). Laboratory data is used to model the equilibrium moisture content and the glass transition temperature of the powder. The resulting...... mathematical model is an index-1 differential algebraic equation (DAE) model with 12 states, 9 inputs, 8 disturbances, and 30 parameters. The parameters in the model are identified from well-excited experimental data obtained from the industrialtype spray dryer. The simulated outputs ofthe model are validated...

  17. Structural neuroimaging across early-stage psychosis: Aberrations in neurobiological trajectories and implications for the staging model.

    Science.gov (United States)

    Bartholomeusz, Cali F; Cropley, Vanessa L; Wannan, Cassandra; Di Biase, Maria; McGorry, Patrick D; Pantelis, Christos

    2017-05-01

    This review critically examines the structural neuroimaging evidence in psychotic illness, with a focus on longitudinal imaging across the first-episode psychosis and ultra-high-risk of psychosis illness stages. A thorough search of the literature involving specifically longitudinal neuroimaging in early illness stages of psychosis was conducted. The evidence supporting abnormalities in brain morphology and altered neurodevelopmental trajectories is discussed in the context of a clinical staging model. In general, grey matter (and, to a lesser extent, white matter) declines across multiple frontal, temporal (especially superior regions), insular and parietal regions during the first episode of psychosis, which has a steeper trajectory than that of age-matched healthy counterparts. Although the ultra-high-risk of psychosis literature is considerably mixed, evidence indicates that certain volumetric structural aberrations predate psychotic illness onset (e.g. prefrontal cortex thinning), while other abnormalities present in ultra-high-risk of psychosis populations are potentially non-psychosis-specific (e.g. hippocampal volume reductions). We highlight the advantages of longitudinal designs, discuss the implications such studies have on clinical staging and provide directions for future research.

  18. Three-stage approach for dynamic traffic temporal-spatial model

    Institute of Scientific and Technical Information of China (English)

    陆化普; 孙智源; 屈闻聪

    2016-01-01

    In order to describe the characteristics of dynamic traffic flow and improve the robustness of its multiple applications, a dynamic traffic temporal-spatial model (DTTS) is established. With consideration of the temporal correlation, spatial correlation and historical correlation, a basic DTTS model is built. And a three-stage approach is put forward for the simplification and calibration of the basic DTTS model. Through critical sections pre-selection and critical time pre-selection, the first stage reduces the variable number of the basic DTTS model. In the second stage, variable coefficient calibration is implemented based on basic model simplification and stepwise regression analysis. Aimed at dynamic noise estimation, the characteristics of noise are summarized and an extreme learning machine is presented in the third stage. A case study based on a real-world road network in Beijing, China, is carried out to test the efficiency and applicability of proposed DTTS model and the three-stage approach.

  19. Stability of an HIV/AIDS Treatment Model with Different Stages

    Directory of Open Access Journals (Sweden)

    Hai-Feng Huo

    2015-01-01

    Full Text Available An HIV/AIDS treatment model with different stages is proposed in this paper. The stage of the HIV infection is divided into two stages, that is, HIV-positive in the asymptomatic stage of HIV infection and HIV-positive individuals in the pre-AIDS stage. The fact that some individuals with HIV-positive individuals after the treatment can be transformed into the compartment of HIV-positive individuals in the asymptomatic stage of HIV infection, the compartment of HIV-positive individuals in the pre-AIDS stage, or the compartment of individuals with full-blown AIDS is also considered. Mathematical analyses establish the idea that the global dynamics of the HIV/AIDS model are determined by the basic reproduction number R0. The disease-free equilibrium is globally asymptotically stable if R01 for a special case. Numerical simulations are also conducted to support the analytic results.

  20. Testing the transtheoretical model for fruit intake: comparing web-based tailored stage-matched and stage-mismatched feedback.

    Science.gov (United States)

    de Vet, Emely; de Nooijer, Jascha; de Vries, Nanne K; Brug, Johannes

    2008-04-01

    A match-mismatch test was conducted to test the transtheoretical model applied to fruit intake. Precontemplators and contemplators were randomly assigned to receive a web-based individualized precontemplation feedback (PCF), contemplation feedback (CF) or action feedback (AF) letter promoting fruit intake. Immediately and 1 week after reading this letter, post-test measures were obtained. Fruit intake increased significantly between pre- and post-test in contemplators, but not in precontemplators. No differences between the feedback conditions were found in fruit intake, stage progression, use or credibility of the feedback in precontemplators and contemplators. In precontemplators, also no differences between the conditions were found in personal relevance of the feedback. Contemplators, however, rated AF as more personally relevant than PCF or CF. To conclude, the present study failed to show superiority of stage-matched information in the promotion of fruit intake.

  1. Counseling Family Members of Addicts/Alcoholics: The Stages of Change Model

    Science.gov (United States)

    van Wormer, Katherine

    2008-01-01

    This article adapts the stages of change model, a model in which specific interventions of harm reduction are directed toward the client's readiness for treatment, as a guiding framework for counseling family members of alcoholics/addicts. Interventions at each stage of the family's readiness for change, from precontemplation to action, are…

  2. In vivo research using early life stage models.

    Science.gov (United States)

    Seabra, Rita; Bhogal, Nirmala

    2010-01-01

    Scientists, for a variety of reasons, need to carry out in vivo research. Since experiments that require the use of adult animals pose various logistical, economical and ethical issues, the use of embryonic and larval forms of some organisms are potentially attractive alternatives. Early life stages are appealing because, in general, large numbers of individuals can be maintained in relatively simple housing, minimising costs, and their use involves fewer legal formalities. With this succinct review, we aim to provide an overview of different biological issues that have been successfully explored with the help of eggs, embryos and larvae from the frog, zebrafish and chicken.

  3. Time-dependent sleep stage transition model based on heart rate variability.

    Science.gov (United States)

    Takeda, Toki; Mizuno, Osamu; Tanaka, Tomohiro

    2015-01-01

    A new model is proposed to automatically classify sleep stages using heart rate variability (HRV). The generative model, based on the characteristics that the distribution and the transition probabilities of sleep stages depend on the elapsed time from the beginning of sleep, infers the sleep stage with a Gibbs sampler. Experiments were conducted using a public data set consisting of 45 healthy subjects and the model's classification accuracy was evaluated for three sleep stages: wake state, rapid eye movement (REM) sleep, and non-REM sleep. Experimental results demonstrated that the model provides more accurate sleep stage classification than conventional (naive Bayes and Support Vector Machine) models that do not take the above characteristics into account. Our study contributes to improve the quality of sleep monitoring in the daily life using easy-to-wear HRV sensors.

  4. Modelled Stage Elevation Shoreline 1274 m3s

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Using widely-available software intended for modeling rivers, a new one-dimensional hydraulic model was developed for the Colorado River through Grand Canyon from...

  5. Modelled Stage Elevation Shoreline 878 m3s

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Using widely-available software intended for modeling rivers, a new one-dimensional hydraulic model was developed for the Colorado River through Grand Canyon from...

  6. Modelled Stage Elevation Shoreline 2747 m3s

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Using widely-available software intended for modeling rivers, a new one-dimensional hydraulic model was developed for the Colorado River through Grand Canyon from...

  7. Modelled Stage Elevation Shoreline 708 m3s

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Using widely-available software intended for modeling rivers, a new one-dimensional hydraulic model was developed for the Colorado River through Grand Canyon from...

  8. The Transtheoretical model for fruit, vegetable and fish consumption: associations between intakes, stages of change and stage transition determinants

    Directory of Open Access Journals (Sweden)

    de Vries Nanne K

    2006-06-01

    Full Text Available Abstract Background Cardiovascular diseases are caused by multiple behavioral factors, including different dietary factors. We examined to what extent fruit, vegetable and fish consumption are related, and whether behavioral determinants vary across these dietary behaviors from a Transtheoretical model perspective. Methods Data were collected among 1142 participants (T0; response rate 46% selected from an Internet panel, who were followed-up one-week later (T1; N = 1055, response rate 92%. Mean age was 35.4 (SD = 11.9 years, 35% was male, and most respondents were of Dutch origin (90%. Of the respondents, 13%, 44% and 43% had a low, medium or high level of education, respectively. Electronic questionnaires assessed fruit, vegetable and fish intake (food frequency questionnaires, stages of change, decisional balance and self-efficacy, for each of these three behaviors. Results Stages of change and (changes in fruit, vegetable and fish intake were only weakly associated; decisional balance and self-efficacy were more strongly associated. Some presumed predictors of stage transitions were similar for fruit, vegetable, and fish intake, i.e., strong pros predicted progress out of precontemplators and low self-efficacy predicted relapse from action/maintenance for all behaviors. However, progress out of contemplation and out of preparation showed different patterns for fruit, vegetable and fish intake. Conclusion The weak associations between intakes and potential determinants for fruit, vegetable, and fish consumption do not warrant an integrated dietary change approach targeting the same determinants for each behavior.

  9. Staged diabetes management. Toward an integrated model of diabetes care.

    Science.gov (United States)

    Mazze, R S; Etzwiler, D D; Strock, E; Peterson, K; McClave, C R; Meszaros, J F; Leigh, C; Owens, L W; Deeb, L C; Peterson, A

    1994-06-01

    This paper introduces a new and innovative approach to diabetes management in the primary-care setting. Staged diabetes management (SDM) represents a four-year effort to develop and test a data-based approach to diabetes management that could be easily adapted to a variety of health-care settings in which diabetes management is principally under the direction of primary-care physicians was limited access to specialists. After testing under controlled circumstances at the International Diabetes Center (Minneapolis, MN), SDM was subjected to substantial field trials under conditions that represent the scope and variety of primary-care practices in diabetes. The following represents the work of several investigators who independently undertook a review of SDM.

  10. Estimation of Large-Scale Implicit Models Using 2-Stage Methods

    Directory of Open Access Journals (Sweden)

    Rolf Henriksen

    1985-01-01

    Full Text Available The problem of estimating large scale implicit (non-recursive models by two- stage methods is considered. The first stage of the methods is used to construct or estimate an explicit form of the total model, by constructing a minimal stochastic realization of the system. This model is then subsequently used in the second stage to generate instrumental variables for the purpose of estimating each sub-model separately. This latter stage can be carried out by utilizing a generalized least squares method, but most emphasis is put on utilizing decentralized filtering algorithms and a prediction error formulation. A note about the connection between the original TSLS-method (two-stage least squares method and stochastic realization is also made.

  11. Consideration sets, intentions and the inclusion of "don't know" in a two-stage model for voter choice

    NARCIS (Netherlands)

    Paap, R; van Nierop, E; van Heerde, HJ; Wedel, M; Franses, PH; Alsem, KJ

    2005-01-01

    We present a statistical model for voter choice that incorporates a consideration set stage and final vote intention stage. The first stage involves a multivariate probit (MVP) model to describe the probabilities that a candidate or a party gets considered. The second stage of the model is a

  12. Intervention model of real-time warning on multidrug-resistant organisms%多药耐药菌实时预警干预模式研究

    Institute of Scientific and Technical Information of China (English)

    陆燕; 张群; 殷瑾; 袁璐

    2013-01-01

    OBJECTIVE To explore the management of intervention model of real-time warning on multidrug-resistant organism (MDROs) and observe the effect. METHODS By means of the real-time monitoring system for alarming 447 strains of MDROs in 2012, the department of nosocomial infection control in joint with the microbiology laboratory and the clinical departments worked together to conduct a prospective investigation and intervention. RESULTS Compared with 66. 0% in 2011, the implementation rate of contact isolation of MDROs was 86. 0% in 2012, increasing by 20. 0% ; the isolation rate of common MDROs dropped by 18. 3% , the methicillin-resistant Staphylococcus aureus dropped by 10. 6%, carbapenems-resistant Escherichia coli 5. 7%, Klebsiella pneumoniae 30.8%, Acinetobacter baumannii 19.5%, and Pseudomonas aeruginosa 26.1%. The utilization rate of antimicrobial agents dropped by 6. 8%; the cost of antibiotic drugs per person decreased by 203. 1 yuan, the incidence of nosocomial infections dropped by 0. 5% , and the rate of etiological examination increased by 5. 2%. CONCLUSION Using the real-time warning on MDROs as the intervention method for monitoring and control and implementing the contact isolation measures in the first place can effectively to prevent the spread of MDROs.%目的 探讨多药耐药菌实时预警干预模式的管理与效果.方法 应用医院感染实时监测系统,医院感染管理科与微生物实验室及临床科室,三位一体,对医院2012年447株多药耐药菌采用计算机自动预警,进行前瞻性调查与干预.结果 2012年多药耐药菌接触隔离执行率86.0%,较2011年66.0%上升20.0%,常见多药耐药菌检出率下降18.3%,其中耐甲氧西林金黄色葡萄球菌(MRSA)、耐碳青霉烯类大肠埃希菌、肺炎克雷伯菌、鲍氏不动杆菌、铜绿假单胞菌检出率分别下降10.6%、5.7%、30.8%、19.5%、26.1%,抗菌药物使用率下降6.8%,人均抗菌药物费用下降203.1

  13. Research and application of a hybrid model based on dynamic fuzzy synthetic evaluation for establishing air quality forecasting and early warning system: A case study in China.

    Science.gov (United States)

    Xu, Yunzhen; Du, Pei; Wang, Jianzhou

    2017-04-01

    As the atmospheric environment pollution has been becoming more and more serious in China, it is highly desirable to develop a scientific and effective early warning system that plays a great significant role in analyzing and monitoring air quality. However, establishing a robust early warning system for warning the public in advance and ameliorating air quality is not only an extremely challenging task but also a public concerned problem for human health. Most previous studies are focused on improving the prediction accuracy, which usually ignore the significance of uncertainty information and comprehensive evaluation concerning air pollutants. Therefore, in this paper a novel robust early warning system was successfully developed, which consists of three modules: evaluation module, forecasting module and characteristics estimating module. In this system, a new dynamic fuzzy synthetic evaluation is proposed and applied to determine air quality levels and primary pollutants, which can be regarded as the research objectives; Moreover, to further mine and analyze the characteristics of air pollutants, four different distribution functions and interval forecasting method are also employed that can not only provide predictive range, confidence level and the other uncertain information of the pollutants future values, but also assist decision-makers in reducing and controlling the emissions of atmospheric pollutants. Case studies utilizing hourly PM2.5, PM10 and SO2 data collected from Tianjin and Shanghai in China are applied as illustrative examples to estimate the effectiveness and efficiency of the proposed system. Experimental results obviously indicated that the developed novel early warning system is much suitable for analyzing and monitoring air pollution, which can also add a novel viable option for decision-makers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. The Construction of Early-warning Index System in Regional Circular Economy of China

    Directory of Open Access Journals (Sweden)

    Kang Yanqing

    2017-01-01

    Full Text Available In this paper, the model of early warning system for circular economy development system was studied, the early-warning system for circular economy provides a quantitative model to support the pollution control. Specifically, this paper built an early warning index system of regional circular economy, and put forward the measure model for the development of circular economy. In addition, this paper constructed prediction model of the circulation economy development. Finally, by the proposed early warning model, this paper analysed the circular economy of Henan province and targeted policy suggestions were put forward for the construction of circular economy of Henan province.

  15. A Study on the Psychological Crisis Early-Warning Model for Students of Pre-school Education Major%幼师生心理危机预警模型研究

    Institute of Scientific and Technical Information of China (English)

    林琳

    2011-01-01

    幼师生心理危机是影响学校稳定和发展的重要因素。针对预警在幼师生心理危机管理中的重要性,结合心理危机产生的原因,提出了幼师生心理危机预警指标体系。考虑到指标信息的模糊性,引入多层次模糊综合评判方法,建立了幼师生心理危机预警模型,以期在实践中得到应用。%The psychological crisis of students' of pre-school education major is an important factor influencing the stability and development of the school. In view of the importance of early warning in management of psychological crisis of students of pre-school education major and the causes of psychological crisis, this paper proposes the psychological crisis early- warning system for students of pre-school education major. Taking into account the ambiguity of index information, multi- level fussy comprehensive evaluation is introduced to construct a psychological crisis early-warning model for students of preschool education major, aiminz to be annlied in nractice.

  16. A Quaternary-Stage User Interest Model Based on User Browsing Behavior and Web Page Classification

    Institute of Scientific and Technical Information of China (English)

    Zongli Jiang; Hang Su

    2012-01-01

    The key to personalized search engine lies in user model. Traditional personalized model results in that the search results of secondary search are partial to the long-term interests, besides, forgetting to the long-term interests disenables effective recollection of user interests. This paper presents a quaternary-stage user interest model based on user browsing behavior and web page classification, which consults the principles of cache and recycle bin in operating system, by setting up an illuminating text-stage and a recycle bin interest-stage in front and rear of the traditional interest model respectively to constitute the quaternary-stage user interest model. The model can better reflect the user interests, by using an adaptive natural weight and its calculation method, and by efficiently integrating user browsing behavior and web document content.

  17. Beyond two-stage models for lung carcinogenesis in the Mayak workers: implications for plutonium risk.

    Directory of Open Access Journals (Sweden)

    Sascha Zöllner

    Full Text Available Mechanistic multi-stage models are used to analyze lung-cancer mortality after Plutonium exposure in the Mayak-workers cohort, with follow-up until 2008. Besides the established two-stage model with clonal expansion, models with three mutation stages as well as a model with two distinct pathways to cancer are studied. The results suggest that three-stage models offer an improved description of the data. The best-fitting models point to a mechanism where radiation increases the rate of clonal expansion. This is interpreted in terms of changes in cell-cycle control mediated by bystander signaling or repopulation following cell killing. No statistical evidence for a two-pathway model is found. To elucidate the implications of the different models for radiation risk, several exposure scenarios are studied. Models with a radiation effect at an early stage show a delayed response and a pronounced drop-off with older ages at exposure. Moreover, the dose-response relationship is strongly nonlinear for all three-stage models, revealing a marked increase above a critical dose.

  18. Modelling a Compliant-Based Precise Positioning Stage

    Directory of Open Access Journals (Sweden)

    Giedrius Augustinavičius

    2012-12-01

    Full Text Available The paper presents modelling precise dual axis flexure-based precision positioning systems for micro-positioning applications. The positioning system is featured with monolithic architecture, flexure-based joints and piezo stacks. Its workspace has been evaluated via analytical approaches. Amplification mechanism is optimally designed. The mathematical model of the positioning system has been derived and verified by resorting to finite element analysis (FEA. The established analytical and (FEA models are helpful for optimizing reliable architecture and improving the performance of the positioning system.

  19. Urban flood risk warning under rapid urbanization.

    Science.gov (United States)

    Chen, Yangbo; Zhou, Haolan; Zhang, Hui; Du, Guoming; Zhou, Jinhui

    2015-05-01

    In the past decades, China has observed rapid urbanization, the nation's urban population reached 50% in 2000, and is still in steady increase. Rapid urbanization in China has an adverse impact on urban hydrological processes, particularly in increasing the urban flood risks and causing serious urban flooding losses. Urban flooding also increases health risks such as causing epidemic disease break out, polluting drinking water and damaging the living environment. In the highly urbanized area, non-engineering measurement is the main way for managing urban flood risk, such as flood risk warning. There is no mature method and pilot study for urban flood risk warning, the purpose of this study is to propose the urban flood risk warning method for the rapidly urbanized Chinese cities. This paper first presented an urban flood forecasting model, which produces urban flood inundation index for urban flood risk warning. The model has 5 modules. The drainage system and grid dividing module divides the whole city terrain into drainage systems according to its first-order river system, and delineates the drainage system into grids based on the spatial structure with irregular gridding technique; the precipitation assimilation module assimilates precipitation for every grids which is used as the model input, which could either be the radar based precipitation estimation or interpolated one from rain gauges; runoff production module classifies the surface into pervious and impervious surface, and employs different methods to calculate the runoff respectively; surface runoff routing module routes the surface runoff and determines the inundation index. The routing on surface grid is calculated according to the two dimensional shallow water unsteady flow algorithm, the routing on land channel and special channel is calculated according to the one dimensional unsteady flow algorithm. This paper then proposed the urban flood risk warning method that is called DPSIR model based

  20. Modelling and Control of the Multi-stage Cable Pulley-driven Flexible-joint Robot

    OpenAIRE

    Phongsaen Pitakwatchara

    2014-01-01

    This work is concerned with the task space impedance control of a robot driven through a multi-stage nonlinear flexible transmission system. Specifically, a two degrees-of-freedom cable pulley-driven flexible-joint robot is considered. Realistic modelling of the system is developed within the bond graph modelling framework. The model captures the nonlinear compliance behaviour of the multi-stage cable pulley transmission system, the spring effect of the augmented counterbalancing mechanism, t...

  1. Analysing outsourcing policies in an asset management context: a six-stage model

    OpenAIRE

    Schoenmaker, R.; Verlaan, J.G.

    2013-01-01

    Asset managers of civil infrastructure are increasingly outsourcing their maintenance. Whereas maintenance is a cyclic process, decisions to outsource decisions are often project-based, and confusing the discussion on the degree of outsourcing. This paper presents a six-stage model that facilitates the top-down discussion for analysing the degree of outsourcing maintenance. The model is based on the cyclic nature of maintenance. The six-stage model can: (1) give clear statements about the pre...

  2. Research of internet worm warning system based on system identification

    Institute of Scientific and Technical Information of China (English)

    Tao ZHOU; Guanzhong DAI; Huimin YE

    2006-01-01

    The frequent explosion of Internet worms has been one of the most serious problems in cyberspace security.In this paper, by analyzing the worm's propagation model, we propose a new worm warning system based on the method of system identification, and use recursive least squares algorithm to estimate the worm's infection rate. The simulation result shows the method we adopted is an efficient way to conduct Internet worm warning.

  3. Evaluation of a prognostic model for risk of relapse in stage I seminoma surveillance

    DEFF Research Database (Denmark)

    Chung, Peter; Daugaard, Gedske; Tyldesley, Scott

    2015-01-01

    A prognostic model for relapse risk in stage I seminoma managed by surveillance after orchiectomy has been developed but has not been independently validated. Individual data on 685 stage I seminoma surveillance patients managed between 1998 and 2005 at three cancer centers were retrospectively...... useful, highly discriminating prognostic model remains elusive in stage I seminoma surveillance as we were unable to validate the previously developed model. However, primary tumor size retained prognostic importance and a scale of relapse risk based on the unit increment of tumor size was developed...

  4. [Prognostic model of the space station contamination stage].

    Science.gov (United States)

    Zlotovol'skiĭ, V M; Smolenskaia, G S

    1998-01-01

    Forty two non-metallic materials, 8 human metabolites and a process liquid (ethylene glycol) were selected for development of a prognostic model of space station contamination by harmful trace admixtures (HTAs). Removal technologies made allowance for absorption by atmospheric condensate (AC) and filter adsorption. Calculations took in 18 HTAs representative of 8 classes of compounds. Simulation modeling allowed to determine HTA migration rates and percent ratio (1), calculate concentrations of contaminants in the atmosphere and atmospheric condensate (2), and to assess filter efficiency by comparison of loads on the filter and a refrigeration/drying set (3). Comparison of empirical and measured data permitted conclusions about adequacy of the model and its potentiality for predicting ramifications of nominal and contingency situations.

  5. Targeted labeling of early-​stage tumor spheroid in chorioallantoic membrane model with upconversion nanoparticles

    NARCIS (Netherlands)

    K. Liu; J.A. Holz; Y. Ding; X. Liu; Y. Zhang; L. Tu; X. Kong; B. Priem; A. Nadort; S.A.G. Lambrechts; M.C.G. Aalders; W.J. Buma; Y. Liu; H. Zhang

    2015-01-01

    In vivo detection of cancer at early-​stage, i.e. smaller than 2 mm, is a challenge in biomedicine. In this work target labeling of early-​stage tumor spheroid (∼500 μm) is realized for the first time in chick embryo chorioallantoic membrane (CAM) model with monoclonal antibody functionalized upconv

  6. Relations of Transtheoretical Model Stage, Self-Efficacy, and Voluntary Physical Activity in African American Preadolescents

    Science.gov (United States)

    Annesi, James J.; Faigenbaum, Avery D.; Westcott, Wayne L.

    2010-01-01

    The transtheoretical model (TTM; Prochaska, DiClemente, & Norcross, 1992) suggests that, at any point, an individual is in one of five stages-of-change related to adopting a behavior. People sequentially advance in stage but may also maintain or even regress, based on personal and environmental factors (Nigg, 2005). A classic study published in…

  7. Why Are There Developmental Stages in Language Learning? A Developmental Robotics Model of Language Development

    Science.gov (United States)

    Morse, Anthony F.; Cangelosi, Angelo

    2017-01-01

    Most theories of learning would predict a gradual acquisition and refinement of skills as learning progresses, and while some highlight exponential growth, this fails to explain why natural cognitive development typically progresses in stages. Models that do span multiple developmental stages typically have parameters to "switch" between…

  8. Relations of Transtheoretical Model Stage, Self-Efficacy, and Voluntary Physical Activity in African American Preadolescents

    Science.gov (United States)

    Annesi, James J.; Faigenbaum, Avery D.; Westcott, Wayne L.

    2010-01-01

    The transtheoretical model (TTM; Prochaska, DiClemente, & Norcross, 1992) suggests that, at any point, an individual is in one of five stages-of-change related to adopting a behavior. People sequentially advance in stage but may also maintain or even regress, based on personal and environmental factors (Nigg, 2005). A classic study published in…

  9. Why Are There Developmental Stages in Language Learning? A Developmental Robotics Model of Language Development

    Science.gov (United States)

    Morse, Anthony F.; Cangelosi, Angelo

    2017-01-01

    Most theories of learning would predict a gradual acquisition and refinement of skills as learning progresses, and while some highlight exponential growth, this fails to explain why natural cognitive development typically progresses in stages. Models that do span multiple developmental stages typically have parameters to "switch" between…

  10. Building performance simulation in the early design stage: An introduction to integrated dynamic models

    DEFF Research Database (Denmark)

    Negendahl, Kristoffer

    2015-01-01

    Designing with building performance simulation feedback in the early design stage has existed since the early days of computational modeling. However, as a consequence of a fragmented building industry building performance simulations (BPSs) in the early design stage are closely related to who is...

  11. A developmental model of hierarchical stage structure in objective moral judgements

    NARCIS (Netherlands)

    J. Boom; P.C.M. Molenaar

    1989-01-01

    A hierarchical structural model of moral judgment is proposed in which an S is characterized as occupying a particular moral stage. During development, the S's characteristic stage progresses along a latent, ordered dimension in an age-dependent way. Evaluation of prototypic statements representativ

  12. Novel three-stage kinetic model for aqueous benzene adsorption on activated carbon.

    Science.gov (United States)

    Choi, Jae-Woo; Choi, Nag-Choul; Lee, Soon-Jae; Kim, Dong-Ju

    2007-10-15

    We propose a novel kinetic model for adsorption of aqueous benzene onto both granular activated carbon (GAC) and powdered activated carbon (PAC). The model is based on mass conservation of benzene coupled with three-stage adsorption: (1) the first portion for an instantaneous stage or external surface adsorption, (2) the second portion for a gradual stage with rate-limiting intraparticle diffusion, and (3) the third portion for a constant stage in which the aqueous phase no longer interacts with activated carbon. An analytical solution of the kinetic model was validated with the kinetic data obtained from aqueous benzene adsorption onto GAC and PAC in batch experiments with two different solution concentrations (C(0)=300 mg L(-1), 600 mg L(-1)). Experimental results revealed that benzene adsorption for the two concentrations followed three distinct stages for PAC but two stages for GAC. The analytical solution could successfully describe the kinetic adsorption of aqueous benzene in the batch reaction system, showing a fast instantaneous adsorption followed by a slow rate-limiting adsorption and a final long constant adsorption. Use of the two-stage model gave incorrect values of adsorption coefficients in the analytical solution due to inability to describe the third stage.

  13. Scrum integration in stage-gate models for collaborative product development

    DEFF Research Database (Denmark)

    Sommer, Anita Friis; Slavensky, Andreas; Nguyen, Vivi Thuy

    2013-01-01

    to differentiate from low-cost competitors and increase PD performance, some industrial manufacturers now seek competitive advantage by experimenting with new ways for collaborative PD. This includes integrating customer-focused agile process models, like Scrum, from the software industry into their existing PD...... models. Thus, instead of replacing traditional stage-gate models agile methods are currently integrated in existing PD models generating hybrid solution for collaborative PD. This paper includes a study of three industrial cases that have successfully integrated Scrum into a stage-gate process model...... for collaborative PD. The paper introduces the three functional hybrid models, including impact on PD performance, PD roles and customer collaboration....

  14. Flash floods: forecasting and warning

    National Research Council Canada - National Science Library

    Sene, Kevin

    2013-01-01

    .... Floods of this type are often characterised by fast flowing deep water and a high debris content which - combined with the short lead time available for warnings - add to the risk to people and property...

  15. The Media Adoption Stage Model of Technology for Art Therapy

    Science.gov (United States)

    Peterson, Brent Christian

    2010-01-01

    This study examined survey data from professional credentialed members of the American Art Therapy Association and 8 follow up interviews to determine how art therapists adopt or reject technology and/or new digital media for therapeutic use with their clients. Using Rogers's (2003) "diffusion of innovation" model, the author identified a…

  16. Dynamic Modelling of a Single Stage Cylindrical Gearbox

    Directory of Open Access Journals (Sweden)

    Zoltan Korka

    2010-10-01

    Full Text Available Gearboxes are frequently used in machine systems for power transmission, speed variation and/or working direction. Dynamic modelling of gear vibration offers a better understanding of the vibration generation mechanisms as well as the dynamic behaviour of the gear transmission in the presence of gear tooth damage.

  17. Thermal properties. Site descriptive modelling Forsmark - stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Back, Paer-Erik; Wrafter, John; Sundberg, Jan [Geo Innova AB (Sweden); Rosen, L ars [Sweco Viak AB (Sweden)

    2007-09-15

    The lithological data acquired from boreholes and mapping of the rock surface need to be reclassified into thermal rock classes, TRCs. The main reason is to simplify the simulations. The lithological data are used to construct models of the transition between different TRCs, thus describing the spatial statistical structure of each TRC. The result is a set of transition probability models that are used in the simulation of TRCs. The intermediate result of this first stochastic simulation is a number of realisations of the geology, each one equally probable. Based on the thermal data, a spatial statistical thermal model is constructed for each TRC. It consists of a statistical distribution and a variogram for each TRC. These are used in the stochastic simulation of thermal conductivity and the result is a number of equally probable realisations of thermal conductivity for the domain. In the next step, the realisations of TRCs (lithology) and thermal conductivity are merged, i.e. each realisation of geology is filled with simulated thermal conductivity values. The result is a set of realisations of thermal conductivity that considers both the difference in thermal properties between different TRCs, and the variability within each TRC. If the result is desired in a scale different from the simulation scale, i.e. the canister scale, upscaling of the realisations can be performed. The result is a set of equally probable realisations of thermal properties. The presented methodology was applied to rock domain RFM029 and RFM045. The main results are sets of realisations of thermal properties that can be used for further processing, most importantly for statistical analysis and numerical temperature simulations for the design of repository layout (distances between deposition holes). The main conclusions of the thermal modelling are: The choice of scale has a profound influence on the distribution of thermal conductivity values. The variance decreases and the lower tail

  18. [Classification of human sleep stages based on EEG processing using hidden Markov models].

    Science.gov (United States)

    Doroshenkov, L G; Konyshev, V A; Selishchev, S V

    2007-01-01

    The goal of this work was to describe an automated system for classification of human sleep stages. Classification of sleep stages is an important problem of diagnosis and treatment of human sleep disorders. The developed classification method is based on calculation of characteristics of the main sleep rhythms. It uses hidden Markov models. The method is highly accurate and provides reliable identification of the main stages of sleep. The results of automatic classification are in good agreement with the results of sleep stage identification performed by an expert somnologist using Rechtschaffen and Kales rules. This substantiates the applicability of the developed classification system to clinical diagnosis.

  19. A model for a liquid membrane separation stage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The coupled mixer-settlers having a common settling zone suggested for use to extract fission products from a conversion reactor blanket are analogues of membrane apparatuses and at a first glance in terms of hydrodynamics do not differ from conventional mixer-settlers. However, the common settling zone complicates both the design solutions and their modelling. For example, different emulsion types can result in mixers and it is not known how this fact will affect phenomena such as separation rates, disperse phase entrainment under conditions close to flooding. For initial studies of the feasibility of the process in principle and the primary optimization of the structure of the transfer scheme one needs to have a model and a program to calculate the statics of a multistage membrane facility of this type.

  20. The discovery of processing stages: analyzing EEG data with hidden semi-Markov models.

    Science.gov (United States)

    Borst, Jelmer P; Anderson, John R

    2015-03-01

    In this paper we propose a new method for identifying processing stages in human information processing. Since the 1860s scientists have used different methods to identify processing stages, usually based on reaction time (RT) differences between conditions. To overcome the limitations of RT-based methods we used hidden semi-Markov models (HSMMs) to analyze EEG data. This HSMM-EEG methodology can identify stages of processing and how they vary with experimental condition. By combining this information with the brain signatures of the identified stages one can infer their function, and deduce underlying cognitive processes. To demonstrate the method we applied it to an associative recognition task. The stage-discovery method indicated that three major processes play a role in associative recognition: a familiarity process, an associative retrieval process, and a decision process. We conclude that the new stage-discovery method can provide valuable insight into human information processing.

  1. Anatomy of Historical Tsunamis: Lessons Learned for Tsunami Warning

    Science.gov (United States)

    Igarashi, Y.; Kong, L.; Yamamoto, M.; McCreery, C. S.

    2011-11-01

    Tsunamis are high-impact disasters that can cause death and destruction locally within a few minutes of their occurrence and across oceans hours, even up to a day, afterward. Efforts to establish tsunami warning systems to protect life and property began in the Pacific after the 1946 Aleutian Islands tsunami caused casualties in Hawaii. Seismic and sea level data were used by a central control center to evaluate tsunamigenic potential and then issue alerts and warnings. The ensuing events of 1952, 1957, and 1960 tested the new system, which continued to expand and evolve from a United States system to an international system in 1965. The Tsunami Warning System in the Pacific (ITSU) steadily improved through the decades as more stations became available in real and near-real time through better communications technology and greater bandwidth. New analysis techniques, coupled with more data of higher quality, resulted in better detection, greater solution accuracy, and more reliable warnings, but limitations still exist in constraining the source and in accurately predicting propagation of the wave from source to shore. Tsunami event data collected over the last two decades through international tsunami science surveys have led to more realistic models for source generation and inundation, and within the warning centers, real-time tsunami wave forecasting will become a reality in the near future. The tsunami warning system is an international cooperative effort amongst countries supported by global and national monitoring networks and dedicated tsunami warning centers; the research community has contributed to the system by advancing and improving its analysis tools. Lessons learned from the earliest tsunamis provided the backbone for the present system, but despite 45 years of experience, the 2004 Indian Ocean tsunami reminded us that tsunamis strike and kill everywhere, not just in the Pacific. Today, a global intergovernmental tsunami warning system is coordinated

  2. TWO-STAGE DECISION MODEL OF SOY FOOD CONSUMPTION BEHAVIOR

    OpenAIRE

    Rimal, Arbindra; Balasubramanian, Siva K.; Moon, Wanki

    2004-01-01

    Our study examined the role of soy health benefits in consumers' soy consumption decision. Given the large number of respondents who reported no consumption of soy products per month, it was important to model the decision of whether or not to participate in soy market separately from the consumption intensity decision. Estimation results demonstrate that knowledge of health benefits affects both the likelihood of participation and consumption intensity. That is, consumers with higher soy hea...

  3. Variation transmission model for setting acceptance criteria in a multi-staged pharmaceutical manufacturing process.

    Science.gov (United States)

    Montes, Richard O

    2012-03-01

    Pharmaceutical manufacturing processes consist of a series of stages (e.g., reaction, workup, isolation) to generate the active pharmaceutical ingredient (API). Outputs at intermediate stages (in-process control) and API need to be controlled within acceptance criteria to assure final drug product quality. In this paper, two methods based on tolerance interval to derive such acceptance criteria will be evaluated. The first method is serial worst case (SWC), an industry risk minimization strategy, wherein input materials and process parameters of a stage are fixed at their worst-case settings to calculate the maximum level expected from the stage. This maximum output then becomes input to the next stage wherein process parameters are again fixed at worst-case setting. The procedure is serially repeated throughout the process until the final stage. The calculated limits using SWC can be artificially high and may not reflect the actual process performance. The second method is the variation transmission (VT) using autoregressive model, wherein variation transmitted up to a stage is estimated by accounting for the recursive structure of the errors at each stage. Computer simulations at varying extent of variation transmission and process stage variability are performed. For the scenarios tested, VT method is demonstrated to better maintain the simulated confidence level and more precisely estimate the true proportion parameter than SWC. Real data examples are also presented that corroborate the findings from the simulation. Overall, VT is recommended for setting acceptance criteria in a multi-staged pharmaceutical manufacturing process.

  4. Late stages of stellar evolution in population models

    Science.gov (United States)

    Maraston, Claudia

    2015-04-01

    My contribution to Roger's celebration symposium focuses on the treatment of late stellar evolutionary phases in stellar population models, reviewing the state of art and discussing some very recent developments, ranging from local stellar clusters up to distant galaxies at high redshift. I shall focus in particular on the Thermally Pulsating Asymptotic Giant Branch, about which a vivid discussion has been ongoing since a few years. I shall present renewed evidence in favour of a sizable contribution from this phase for matching the observed spectral energy distribution of distant massive galaxies. I shall also discuss the possible reasons why such a conclusion has been controversial in the recent literature. Stellar population models are the magic tool to shape the physics of galaxies out of their observed light, and enter virtually all papers presented at this symposium. In a collective effort to properly treat all relevant aspects of the modelling, we split the discussion into six contributions given by experts in the field, as our present to Roger and his outstanding career.

  5. Marginal estimation for multi-stage models: waiting time distributions and competing risks analyses.

    Science.gov (United States)

    Satten, Glen A; Datta, Somnath

    2002-01-15

    We provide non-parametric estimates of the marginal cumulative distribution of stage occupation times (waiting times) and non-parametric estimates of marginal cumulative incidence function (proportion of persons who leave stage j for stage j' within time t of entering stage j) using right-censored data from a multi-stage model. We allow for stage and path dependent censoring where the censoring hazard for an individual may depend on his or her natural covariate history such as the collection of stages visited before the current stage and their occupation times. Additional external time dependent covariates that may induce dependent censoring can also be incorporated into our estimates, if available. Our approach requires modelling the censoring hazard so that an estimate of the integrated censoring hazard can be used in constructing the estimates of the waiting times distributions. For this purpose, we propose the use of an additive hazard model which results in very flexible (robust) estimates. Examples based on data from burn patients and simulated data with tracking are also provided to demonstrate the performance of our estimators.

  6. ANALYSIS OF AN SI EPIDEMIC MODEL WITH NONLINEAR TRANSMISSION AND STAGE STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    陆忠华; 高淑京; 陈兰荪

    2003-01-01

    A disease transmission model of SI type with stage structure is formulated.The stability of disease free equilibrium, the existence and uniqueness of an endemic equi-librium, the existence of a global attractor are investigated.

  7. Three stage maturity model in SME’s toward industry 4.0

    OpenAIRE

    Jaione Ganzarain; Nekane Errasti

    2016-01-01

    Purpose: To address the challenges regarding the concept of Industry 4.0 and the diversification methodology and based on the strategic guidance towards Industry 4.0, we propose a process model as a guiding framework for Industry 4.0 collaborative diversification vision, strategy and action building. In this paper we suggest a stage process model to guide and train companies to identify new opportunities for diversification within Industry 4.0. Systematically carrying out the stages will take...

  8. Numerical and experimental modelling of the centrifugal compressor stage – setting the model of impellers with 2D blades

    Directory of Open Access Journals (Sweden)

    Matas Richard

    2017-01-01

    Full Text Available The article deals with a description of results from research and development of a radial compressor stage. The experimental compressor and used numerical models are briefly described. In the first part, the comparisons of characteristics obtained experimentally and by numerical simulations for stage with vaneless diffuser are described. In the second part, the results for stage with vanned diffuser are presented. The results are relevant for next studies in research and development process.

  9. Modelling early stages of relativistic heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Ruggieri M.

    2016-01-01

    Full Text Available In this study we model early time dynamics of relativistic heavy ion collisions by an initial color-electric field which then decays to a plasma by the Schwinger mechanism. The dynamics of the many particles system produced by the decay is described by relativistic kinetic theory, taking into account the backreaction on the color field by solving self-consistently the kinetic and the field equations. Our main results concern isotropization and thermalization for a 1+1D expanding geometry. In case of small η/s (η/s ≲ 0.3 we find τisotropization ≈ 0.8 fm/c and τthermalization ≈ 1 fm/c in agreement with the common lore of hydrodynamics.

  10. Air quality early-warning system for cities in China

    Science.gov (United States)

    Xu, Yunzhen; Yang, Wendong; Wang, Jianzhou

    2017-01-01

    Air pollution has become a serious issue in many developing countries, especially in China, and could generate adverse effects on human beings. Air quality early-warning systems play an increasingly significant role in regulatory plans that reduce and control emissions of air pollutants and inform the public in advance when harmful air pollution is foreseen. However, building a robust early-warning system that will improve the ability of early-warning is not only a challenge but also a critical issue for the entire society. Relevant research is still poor in China and cannot always satisfy the growing requirements of regulatory planning, despite the issue's significance. Therefore, in this paper, a hybrid air quality early-warning system was successfully developed, composed of forecasting and evaluation. First, a hybrid forecasting model was proposed as an important part of this system based on the theory of "decomposition and ensemble" and combined with the advanced data processing technique, support vector machine, the latest bio-inspired optimization algorithm and the leave-one-out strategy for deciding weights. Afterwards, to intensify the research, fuzzy evaluation was performed, which also plays an indispensable role in the early-warning system. The forecasting model and fuzzy evaluation approaches are complementary. Case studies using daily air pollution concentrations of six air pollutants from three cities in China (i.e., Taiyuan, Harbin and Chongqing) are used as examples to evaluate the efficiency and effectiveness of the developed air quality early-warning system. Experimental results demonstrate that both the accuracy and the effectiveness of the developed system are greatly superior for air quality early warning. Furthermore, the application of forecasting and evaluation enables the informative and effective quantification of future air quality, offering a significant advantage, and can be employed to develop rapid air quality early-warning systems.

  11. Loss Function Based Ranking in Two-Stage, Hierarchical Models

    Science.gov (United States)

    Lin, Rongheng; Louis, Thomas A.; Paddock, Susan M.; Ridgeway, Greg

    2009-01-01

    Performance evaluations of health services providers burgeons. Similarly, analyzing spatially related health information, ranking teachers and schools, and identification of differentially expressed genes are increasing in prevalence and importance. Goals include valid and efficient ranking of units for profiling and league tables, identification of excellent and poor performers, the most differentially expressed genes, and determining “exceedances” (how many and which unit-specific true parameters exceed a threshold). These data and inferential goals require a hierarchical, Bayesian model that accounts for nesting relations and identifies both population values and random effects for unit-specific parameters. Furthermore, the Bayesian approach coupled with optimizing a loss function provides a framework for computing non-standard inferences such as ranks and histograms. Estimated ranks that minimize Squared Error Loss (SEL) between the true and estimated ranks have been investigated. The posterior mean ranks minimize SEL and are “general purpose,” relevant to a broad spectrum of ranking goals. However, other loss functions and optimizing ranks that are tuned to application-specific goals require identification and evaluation. For example, when the goal is to identify the relatively good (e.g., in the upper 10%) or relatively poor performers, a loss function that penalizes classification errors produces estimates that minimize the error rate. We construct loss functions that address this and other goals, developing a unified framework that facilitates generating candidate estimates, comparing approaches and producing data analytic performance summaries. We compare performance for a fully parametric, hierarchical model with Gaussian sampling distribution under Gaussian and a mixture of Gaussians prior distributions. We illustrate approaches via analysis of standardized mortality ratio data from the United States Renal Data System. Results show that SEL

  12. 78 FR 8535 - Medicare Program: Comprehensive End-Stage Renal Disease Care Model Announcement

    Science.gov (United States)

    2013-02-06

    ... Disease Care Model Announcement AGENCY: Centers for Medicare & Medicaid Services (CMS), HHS. ACTION... the testing of the Comprehensive End- Stage Renal Disease (ESRD) Care Model, a new initiative from the... (CHIP) beneficiaries. We are interested in identifying models designed to improve care for...

  13. A Multi-Stage Optimization Model With Minimum Energy Consumption-Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    S. Krishnakumar

    2012-09-01

    Full Text Available Optimization models related with routing, bandwidth utilization and power consumption are developed in the wireless mesh computing environment using the operations research techniques such as maximal flow model, transshipment model and minimax optimizing algorithm. The Path creation algorithm is used to find the multiple paths from source to destination.A multi-stage optimization model is developed by combining the multi-path optimization model, optimization model in capacity utilization and energy optimization model and minimax optimizing algorithm. The input to the multi-stage optimization model is a network with many source and destination. The optimal solution obtained from this model is a minimum energy consuming path from source to destination along with the maximum data rate over each link. The performance is evaluated by comparing the data rate values of superimposed algorithm and minimax optimizing algorithm. The main advantage of this model is the reduction of traffic congestion in the network.

  14. A four-stage hybrid model for hydrological time series forecasting.

    Science.gov (United States)

    Di, Chongli; Yang, Xiaohua; Wang, Xiaochao

    2014-01-01

    Hydrological time series forecasting remains a difficult task due to its complicated nonlinear, non-stationary and multi-scale characteristics. To solve this difficulty and improve the prediction accuracy, a novel four-stage hybrid model is proposed for hydrological time series forecasting based on the principle of 'denoising, decomposition and ensemble'. The proposed model has four stages, i.e., denoising, decomposition, components prediction and ensemble. In the denoising stage, the empirical mode decomposition (EMD) method is utilized to reduce the noises in the hydrological time series. Then, an improved method of EMD, the ensemble empirical mode decomposition (EEMD), is applied to decompose the denoised series into a number of intrinsic mode function (IMF) components and one residual component. Next, the radial basis function neural network (RBFNN) is adopted to predict the trend of all of the components obtained in the decomposition stage. In the final ensemble prediction stage, the forecasting results of all of the IMF and residual components obtained in the third stage are combined to generate the final prediction results, using a linear neural network (LNN) model. For illustration and verification, six hydrological cases with different characteristics are used to test the effectiveness of the proposed model. The proposed hybrid model performs better than conventional single models, the hybrid models without denoising or decomposition and the hybrid models based on other methods, such as the wavelet analysis (WA)-based hybrid models. In addition, the denoising and decomposition strategies decrease the complexity of the series and reduce the difficulties of the forecasting. With its effective denoising and accurate decomposition ability, high prediction precision and wide applicability, the new model is very promising for complex time series forecasting. This new forecast model is an extension of nonlinear prediction models.

  15. Hydrogeological characterisation and modelling of deformation zones and fracture domains, Forsmark modelling stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven (SF GeoLogic AB, Taeby (SE)); Leven, Jakob (Swedish Nuclear Fuel and Waste Management Co., Stockholm (SE)); Hartley, Lee; Jackson, Peter; Joyce, Steve; Roberts, David; Swift, Ben (Serco Assurance, Harwell (GB))

    2007-09-15

    The work reported here collates the structural-hydraulic information gathered in 21 cored boreholes and 32 percussion-drilled boreholes belonging to Forsmark site description, modelling stage 2.2. The analyses carried out provide the hydrogeological input descriptions of the bedrock in Forsmark needed by the end users Repository Engineering, Safety Assessment and Environmental Impact Assessment; that is, hydraulic properties of deformation zones and fracture domains. The same information is also needed for constructing 3D groundwater flow models of the Forsmark site and surrounding area. The analyses carried out render the following conceptual model regarding the observed heterogeneity in deformation zone transmissivity: We find the geological division of the deterministically modelled deformation zones into eight categories (sets) useful from a hydrogeological point of view. Seven of the eight categories are steeply dipping, WNW, NW, NNW, NNE, NE, ENE and EW, and on is gently dipping, G. All deformation zones, regardless of orientation (strike and dip), are subjected to a substantial decrease in transmissivity with depth. The data gathered suggest a contrast of c. 20,000 times for the uppermost one kilometre of bedrock, i.e. more than four orders of magnitude. The hydraulic properties below this depth are not investigated. The lateral heterogeneity is also substantial but more irregular in its appearance. For instance, for a given elevation and deformation zone category (orientation), the spatial variability in transmissivity within a particular deformation zone appears to be as large as the variability between all deformation zones. This suggests that the lateral correlation length is shorter than the shortest distance between two adjacent observation points and shorter than the category spacing. The observation that the mean transmissivity of the gently-dipping deformation zones is c. one to two orders of magnitude greater than the mean transmissivities of all

  16. Physically based landslide warning at regional scale

    Science.gov (United States)

    Canli, Ekrem; Mergili, Martin; Glade, Thomas

    2017-04-01

    Albeit advancements in the past within the field of geotechnical engineering have led to an increasing in situ damage control in many parts of the world, heavy rainstorms still cause severe damage by triggering landslides. Landslides are usually restricted to the local scale when taking into consideration single events, however, they often tend to occur spatially abundant which makes them a regional phenomenon. This makes the necessity of regional-scale early warning systems (EWS) indispensable. When dealing with landslide EWS, it is impossible to cover all potential early warning situations. Although the calculation of rainfall thresholds is the most common approach for assessing regional landslide early warning, they only represent a simplification of the physical processes involved. In most cases, indeed, there is more than just this one causative factor involved. Here, we present an early prototype for a regional, physically based landslide EWS driven by real-time spatio-temporal rainfall data. Instead of assuming uniform rainfall over a certain area, an automated geostatistical approach is suggested which allows approximating real-time spatially distributed, hourly rainfall predictions based on gauged rainfall data available on the internet. The methodology presented in this study is especially suitable for the implementation in warning systems that contain predefined thresholds and for landslides related to a progressive increase of soil saturation and/or a rising groundwater table. The transient rainfall infiltration and grid-based slope stability (TRIGRS) model is used in a modified way to compute transient pore-pressure changes and associated changes in the factor of safety due to rainfall infiltration. The geotechnical properties involved are probabilistically integrated within certain predefined ranges to account for the inherent spatial uncertainties. The result is an automatically generated probability of failure raster map that is updated hourly based

  17. Scrum integration in stage-gate models for collaborative product development

    DEFF Research Database (Denmark)

    Sommer, Anita Friis; Slavensky, Andreas; Nguyen, Vivi Thuy

    2013-01-01

    The relevance of collaborative Product Development (PD) is rising with the decrease of product life cycles combined with growing customer demands. Industrial manufacturers now experience competition in the global market, where differentiation is necessary for survival. Hence, in order...... models. Thus, instead of replacing traditional stage-gate models agile methods are currently integrated in existing PD models generating hybrid solution for collaborative PD. This paper includes a study of three industrial cases that have successfully integrated Scrum into a stage-gate process model...

  18. Stability patterns for a size-structured population model and its stage-structured counterpart

    DEFF Research Database (Denmark)

    Zhang, Lai; Pedersen, Michael; Lin, Zhigui

    2015-01-01

    In this paper we compare a general size-structured population model, where a size-structured consumer feeds upon an unstructured resource, to its simplified stage-structured counterpart in terms of equilibrium stability. Stability of the size-structured model is understood in terms of an equivalent...... delayed system consisting of a renewal equation for the consumer population birth rate and a delayed differential equation for the resource. Results show that the size- and stage-structured models differ considerably with respect to equilibrium stability, although the two models have completely identical...

  19. EVALUATING EFFECTIVENESS OF MOBILE BROWSER SECURITY WARNINGS

    Directory of Open Access Journals (Sweden)

    Ronak Shah

    2016-09-01

    Full Text Available This work precisely evaluates whether browser security warnings are as ineffective as proposed by popular sentiments and past writings. This research used different kinds of Android mobile browsers as well as desktop browsers to evaluate security warnings. Security experts and developers should give emphasis on making a user aware of security warnings and should not neglect aim of communicating this to users. Security experts and system architects should emphasis the goal of communicating security information to end users. In most of the browsers, security warnings are not emphasized, and browsers simply do not show warnings, or there are a number of ways to hide those warnings of malicious sites. This work precisely finds that how inconsistent browsers really are in prompting security warnings. In particular, majority of the modern mobile web browsers are vulnerable to these security threats. We find inconsistency in SSL warnings among web browsers. Based on this work, we make recommendations for warning designers and researchers.

  20. A quantification model for apoptosis in mouse embryos in the early stage of fetation

    Institute of Scientific and Technical Information of China (English)

    WANG PengFei; FU JianHua; MA WanYun; CHEN DieYan; Lü DanYu; BAI WenJia

    2009-01-01

    Apoptosis is the most important inducement and modulator for embryos in the early stage of fetation, i.e. after the 8-cell stage, mostly the morula and blastula stage, to proceed to the stage of nonlinear development. Using a two-photon laser scanning microscopy (TPLSM) system, we obtained 3-dimensional (3D) fluorescent images of preimplantation mouse embryos. A model for quantification was established. The statistical results for the spatial location of apoptosis bodies in embryos was obtained following image processing, as well as investigation of the kinetics of apoptosis. It was found that most (70%) apoptosis occurred in the trophectoderm, and the departure between the centroid and geometric center of embryos had a step transition when embryos developed into the 32-cell stage,which was consistent with the theoretical prediction that the blastocele would induce a symmetry break of the distribution of cells in embryos.

  1. A quantification model for apoptosis in mouse embryos in the early stage of fetation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Apoptosis is the most important inducement and modulator for embryos in the early stage of fetation, i.e. after the 8-cell stage, mostly the morula and blastula stage, to proceed to the stage of nonlinear development. Using a two-photon laser scanning microscopy (TPLSM) system, we obtained 3-dimensional (3D) fluorescent images of preimplantation mouse embryos. A model for quantification was established. The statistical results for the spatial location of apoptosis bodies in embryos was obtained following image processing, as well as investigation of the kinetics of apoptosis. It was found that most (70%) apoptosis occurred in the trophectoderm, and the departure between the centroid and geometric center of embryos had a step transition when embryos developed into the 32-cell stage, which was consistent with the theoretical prediction that the blastocele would induce a symmetry break of the distribution of cells in embryos.

  2. Multisensory in-car warning signals for collision avoidance.

    Science.gov (United States)

    Ho, Cristy; Reed, Nick; Spence, Charles

    2007-12-01

    A driving simulator study was conducted in order to assess the relative utility of unimodal auditory, unimodal vibrotactile, and combined audiotactile (i.e., multisensory) in-car warning signals to alert and inform drivers of likely front-to-rear-end collision events in a situation modeled on real-world driving. The implementation of nonvisual in-car warning signals may have important safety implications in lessening any visual overload during driving. Multisensory integration can provide synergistic facilitation effects. The participants drove along a rural road in a car-following scenario in either the presence or absence of a radio program in the background. The brake light signals of the lead vehicle were also unpredictably either enabled or disabled on a trial-by-trial basis. The results showed that the participants initiated their braking responses significantly more rapidly following the presentation of audiotactile warning signals than following the presentation of either unimodal auditory or unimodal vibrotactile warning signals. Multisensory warning signals offer a particularly effective means of capturing driver attention in demanding situations such as driving. The potential value of such multisensory in-car warning signals is explained with reference to recent cognitive neuroscience research.

  3. Stages of Change Model for Participation in Physical Activity during Pregnancy

    Directory of Open Access Journals (Sweden)

    Lene Annette Hagen Haakstad

    2013-01-01

    Full Text Available Background. The transtheoretical model (TTM has been successful in promoting health behavioral change in the general population. However, there is a scant knowledge about physical activity in relation to the TTM during pregnancy. Hence, the aims of the present study were (1 to assess readiness to become or stay physically active according to the TTM and (2 to compare background and health variables across the TTM. Methods. Healthy pregnant women (n=467 were allocated to the study from Oslo University Hospital, Norway. The participants filled in a validated self-administered questionnaire, physical activity pregnancy questionnaire (PAPQ in gestation, weeks 32–36. The questionnaire contained 53 questions with one particular question addressing the TTM and the five stages: (1 precontemplation stage, (2 contemplation stage, (3 preparation stage, (4 action stage, and (5 maintenance stage. Results. More than half of the participants (53% were involved in regular exercise (stages 4-5; however, only six specified that they had recently started an exercise program (stage 4. About 33% reported engaging in some physical activity, but not regularly (stage 3. The results showed that receiving advice from health professionals to exercise during pregnancy increased the likeliness of being in stages 4-5, while higher age, multiparity, pregravid overweight, unhealthy eating habits, pelvic girdle pain, and urinary incontinence were more prevalent with low readiness to change exercise habits (stages 1–3. Conclusion. According to the TTM, more than half of the participants reported to be physically active. Moreover, most of the participants classified as inactive showed a high motivational readiness or intention to increase their physical activity level. Hence, pregnancy may be a window of opportunity for the establishment of long-term physical activity habits.

  4. Early warning signals of desertification transitions in semiarid ecosystems

    Science.gov (United States)

    Corrado, Raffaele; Cherubini, Anna Maria; Pennetta, Cecilia

    2014-12-01

    The identification of early warning signals for regime shifts in ecosystems is of crucial importance given their impact in terms of economic and social effects. We present here the results of a theoretical study on the desertification transition in semiarid ecosystems under external stress. We performed numerical simulations based on a stochastic cellular automaton model, and we studied the dynamics of the vegetation clusters in terms of percolation theory, assumed as an effective tool for analyzing the geometrical properties of the clusters. Focusing on the role played by the strength of external stresses, measured by the mortality rate m , we followed the progressive degradation of the ecosystem for increasing m , identifying different stages: first, the fragmentation transition occurring at relatively low values of m , then the desertification transition at higher mortality rates, and finally the full desertification transition corresponding to the extinction of the vegetation and the almost complete degradation of the soil, attained at the maximum value of m . For each transition we calculated the spanning probabilities as functions of m and the percolation thresholds according to different spanning criteria. The identification of the different thresholds is proposed as an useful tool for monitoring the increasing degradation of real-world finite-size systems. Moreover, we studied the time fluctuations of the sizes of the biggest clusters of vegetated and nonvegetated cells over the entire range of mortality values. The change of sign in the skewness of the size distributions, occurring at the fragmentation threshold for the biggest vegetation cluster and at the desertification threshold for the nonvegetated cluster, offers new early warning signals for desertification. Other new and robust indicators are given by the maxima of the root-mean-square deviation of the distributions, which are attained respectively inside the fragmentation interval, for the

  5. An Enhanced Preventive Maintenance Optimization Model Based on a Three-Stage Failure Process

    Directory of Open Access Journals (Sweden)

    Ruifeng Yang

    2015-01-01

    Full Text Available Nuclear power plants are highly complex systems and the issues related to their safety are of primary importance. Probabilistic safety assessment is regarded as the most widespread methodology for studying the safety of nuclear power plants. As maintenance is one of the most important factors for affecting the reliability and safety, an enhanced preventive maintenance optimization model based on a three-stage failure process is proposed. Preventive maintenance is still a dominant maintenance policy due to its easy implementation. In order to correspond to the three-color scheme commonly used in practice, the lifetime of system before failure is divided into three stages, namely, normal, minor defective, and severe defective stages. When the minor defective stage is identified, two measures are considered for comparison: one is that halving the inspection interval only when the minor defective stage is identified at the first time; the other one is that if only identifying the minor defective stage, the subsequent inspection interval is halved. Maintenance is implemented immediately once the severe defective stage is identified. Minimizing the expected cost per unit time is our objective function to optimize the inspection interval. Finally, a numerical example is presented to illustrate the effectiveness of the proposed models.

  6. Applying a stage model of behavior change to colon cancer screening.

    Science.gov (United States)

    Costanza, Mary E; Luckmann, Roger; Stoddard, Anne M; Avrunin, Jill S; White, Mary Jo; Stark, Jennifer R; Clemow, Lynn; Rosal, Milagros C

    2005-01-01

    There has been limited use of stages of change models in characterizing colorectal cancer (CRC) screening. We assess the applicability of the Precaution Adoption Model (PAPM) by determining the distribution of stages of adoption and by elucidating differences among stages. The study is based on 1394 responses (69%) to a survey mailed in 2002 to patients in a primary care population. Survey measures included: self-reported CRC screening, sociodemographic characteristics, health system characteristics, attitudes and beliefs about CRC screening, perceived vulnerability to CRC, and worry about CRC. The main outcome was PAPM stage of adoption of CRC screening based on the ACS preferred guidelines: colonoscopy every 10 years alone or the combination annual FOBT plus sigmoidoscopy every 5 years. 57% were up-to-date with at least one test; 36% were up-to-date with the ACS preferred guidelines; provider recommendation, positive family history of CRC, and positive decisional balance score were significantly associated with higher compared to lower PAPM stages. The combination of PAPM stage assignment and other factors provides useful information for designing tailored interventions. There are special challenges in developing and interpreting PAPM stage assignments when a guideline offers multiple pathways to adherence and recommends a combination of two tests as a preferred option.

  7. Macro finance early warning system

    Institute of Scientific and Technical Information of China (English)

    Guihuan ZHENG; Xun ZHANG; Wei SHANG; Shanying XU

    2009-01-01

    In this paper, a financial early warning informa-tion system is developed based on the multi-dimensional cli-mate approach that is featured with a multi-dimensional in-dex construction and the relevant multi-dimensional analy-sis. Requirement analysis and design issues of building an information system supporting this multi-dimensional cli-mate approach are discussed in detail. And a case using this system to study the macro financial issues is presented to illustrate how the proposed multi-dimensional approach works in the information system we design. This research is an interdisciplinary work of economic theories, macro finan-cial empirical studies, and software engineering. With ad-vanced macro financial early warning theories implemented in a web application, the Macro Financial Early Warning System (FEWS) developed in this research has been proved to be effective in a trial running in the Forecasting research institute of the Chinese Academy of Sciences.

  8. Modelling of two-stage anaerobic digestion using the IWA Anaerobic Digestion Model No. 1 (ADM1).

    Science.gov (United States)

    Blumensaat, F; Keller, J

    2005-01-01

    The aim of the study presented was to implement a process model to simulate the dynamic behaviour of a pilot-scale process for anaerobic two-stage digestion of sewage sludge. The model implemented was initiated to support experimental investigations of the anaerobic two-stage digestion process. The model concept implemented in the simulation software package MATLAB/Simulink is a derivative of the IWA Anaerobic Digestion Model No.1 (ADM1) that has been developed by the IWA task group for mathematical modelling of anaerobic processes. In the present study the original model concept has been adapted and applied to replicate a two-stage digestion process. Testing procedures, including balance checks and 'benchmarking' tests were carried out to verify the accuracy of the implementation. These combined measures ensured a faultless model implementation without numerical inconsistencies. Parameters for both, the thermophilic and the mesophilic process stage, have been estimated successfully using data from lab-scale experiments described in literature. Due to the high number of parameters in the structured model, it was necessary to develop a customised procedure that limited the range of parameters to be estimated. The accuracy of the optimised parameter sets has been assessed against experimental data from pilot-scale experiments. Under these conditions, the model predicted reasonably well the dynamic behaviour of a two-stage digestion process in pilot scale.

  9. Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application

    OpenAIRE

    Zhanghua Lian; Ying Zhang; Xu Zhao; Shidong Ding; Tiejun Lin

    2015-01-01

    Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs, but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time. In view of this, based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well, mechanical models were established for three working cases of multiple packer setting, ...

  10. Simulink Model of the Ares I Upper Stage Main Propulsion System

    Science.gov (United States)

    Burchett, Bradley T.

    2008-01-01

    A numerical model of the Ares I upper stage main propulsion system is formulated based on first principles. Equation's are written as non-linear ordinary differential equations. The GASP fortran code is used to compute thermophysical properties of the working fluids. Complicated algebraic constraints are numerically solved. The model is implemented in Simulink and provides a rudimentary simulation of the time history of important pressures and temperatures during re-pressurization, boost and upper stage firing. The model is validated against an existing reliable code, and typical results are shown.

  11. Modified landfill gas generation rate model of first-order kinetics and two-stage reaction

    Institute of Scientific and Technical Information of China (English)

    Jiajun CHEN; Hao WANG; Na ZHANG

    2009-01-01

    This investigation was carried out to establish a new domestic landfill gas (LFG) generation rate model that takes into account the impact ofleachate recirculation. The first-order kinetics and two-stage reaction (FKTSR) model of the LFG generation rate includes mechanisms of the nutrient balance for biochemical reaction in two main stages. In this study, the FKTSR model was modified by the introduction of the outflow function and the organic acid conversion coefficient in order to represent the in-situ condition of nutrient loss through leachate. Laboratory experiments were carried out to simulate the impact of leachate recirculation and verify the modified FKTSR model. The model calibration was then calculated by using the experimental data. The results suggested that the new model was in line with the experimental data. The main parameters of the modified FKTSR model, including the LFG production potential (L0), the reaction rate constant in the first stage (K1), and the reaction rate constant in the second stage (K2) of 64.746 L, 0.202 d-1, and 0.338 d-1,respectively, were comparable to the old ones of 42.069 L,0.231 d-1, and 0.231 d-1. The new model is better able to explain the mechanisms involved in LFG generation.

  12. Two-stage estimation in copula models used in family studies

    DEFF Research Database (Denmark)

    Andersen, Elisabeth Anne Wreford

    2005-01-01

    In this paper register based family studies provide the motivation for studying a two-stage estimation procedure in copula models for multivariate failure time data. The asymptotic properties of the estimators in both parametric and semi-parametric models are derived, generalising the approach by...

  13. Why Are There Developmental Stages in Language Learning? A Developmental Robotics Model of Language Development.

    Science.gov (United States)

    Morse, Anthony F; Cangelosi, Angelo

    2017-02-01

    Most theories of learning would predict a gradual acquisition and refinement of skills as learning progresses, and while some highlight exponential growth, this fails to explain why natural cognitive development typically progresses in stages. Models that do span multiple developmental stages typically have parameters to "switch" between stages. We argue that by taking an embodied view, the interaction between learning mechanisms, the resulting behavior of the agent, and the opportunities for learning that the environment provides can account for the stage-wise development of cognitive abilities. We summarize work relevant to this hypothesis and suggest two simple mechanisms that account for some developmental transitions: neural readiness focuses on changes in the neural substrate resulting from ongoing learning, and perceptual readiness focuses on the perceptual requirements for learning new tasks. Previous work has demonstrated these mechanisms in replications of a wide variety of infant language experiments, spanning multiple developmental stages. Here we piece this work together as a single model of ongoing learning with no parameter changes at all. The model, an instance of the Epigenetic Robotics Architecture (Morse et al 2010) embodied on the iCub humanoid robot, exhibits ongoing multi-stage development while learning pre-linguistic and then basic language skills. Copyright © 2016 Cognitive Science Society, Inc.

  14. Desire versus efficacy in smokers' paradoxical reactions to pictorial health warnings for cigarettes.

    Directory of Open Access Journals (Sweden)

    Daniel Romer

    Full Text Available Pictorial health warnings on cigarette packs create aversive emotional reactions to smoking and induce thoughts about quitting; however, contrary to models of health behavior change, they do not appear to alter intentions to quit smoking. We propose and test a novel model of intention to quit an addictive habit such as smoking (the efficacy-desire model that can explain this paradoxical effect. At the core of the model is the prediction that self-efficacy and desire to quit an addictive habit are inversely related. We tested the model in an online experiment that randomly exposed smokers (N = 3297 to a cigarette pack with one of three increasing levels of warning intensity. The results supported the model's prediction that despite the effects of warnings on aversion to smoking, intention to quit smoking is an inverted U-shape function of the smoker's self-efficacy for quitting. In addition, smokers with greater (lesser quit efficacy relative to smoking efficacy increase (decrease intentions to quit. The findings show that previous failures to observe effects of pictorial warning labels on quit intentions can be explained by the contradictory individual differences that warnings produce. Thus, the model explains the paradoxical finding that quit intentions do not change at the population level, even though smokers recognize the implications of warnings. The model suggests that pictorial warnings are effective for smokers with stronger quit-efficacy beliefs and provides guidance for how cigarette warnings and tobacco control strategies can be designed to help smokers quit.

  15. Modeling screening, prevention, and delaying of Alzheimer's disease: an early-stage decision analytic model

    Directory of Open Access Journals (Sweden)

    Siemers Eric R

    2010-04-01

    Full Text Available Abstract Background Alzheimer's Disease (AD affects a growing proportion of the population each year. Novel therapies on the horizon may slow the progress of AD symptoms and avoid cases altogether. Initiating treatment for the underlying pathology of AD would ideally be based on biomarker screening tools identifying pre-symptomatic individuals. Early-stage modeling provides estimates of potential outcomes and informs policy development. Methods A time-to-event (TTE simulation provided estimates of screening asymptomatic patients in the general population age ≥55 and treatment impact on the number of patients reaching AD. Patients were followed from AD screen until all-cause death. Baseline sensitivity and specificity were 0.87 and 0.78, with treatment on positive screen. Treatment slowed progression by 50%. Events were scheduled using literature-based age-dependent incidences of AD and death. Results The base case results indicated increased AD free years (AD-FYs through delays in onset and a reduction of 20 AD cases per 1000 screened individuals. Patients completely avoiding AD accounted for 61% of the incremental AD-FYs gained. Total years of treatment per 1000 screened patients was 2,611. The number-needed-to-screen was 51 and the number-needed-to-treat was 12 to avoid one case of AD. One-way sensitivity analysis indicated that duration of screening sensitivity and rescreen interval impact AD-FYs the most. A two-way sensitivity analysis found that for a test with an extended duration of sensitivity (15 years the number of AD cases avoided was 6,000-7,000 cases for a test with higher sensitivity and specificity (0.90,0.90. Conclusions This study yielded valuable parameter range estimates at an early stage in the study of screening for AD. Analysis identified duration of screening sensitivity as a key variable that may be unavailable from clinical trials.

  16. Prey-Predator Model with Two-Stage Infection in Prey: Concerning Pest Control

    Directory of Open Access Journals (Sweden)

    Swapan Kumar Nandi

    2015-01-01

    Full Text Available A prey-predator model system is developed; specifically the disease is considered into the prey population. Here the prey population is taken as pest and the predators consume the selected pest. Moreover, we assume that the prey species is infected with a viral disease forming into susceptible and two-stage infected classes, and the early stage of infected prey is more vulnerable to predation by the predator. Also, it is assumed that the later stage of infected pests is not eaten by the predator. Different equilibria of the system are investigated and their stability analysis and Hopf bifurcation of the system around the interior equilibriums are discussed. A modified model has been constructed by considering some alternative source of food for the predator population and the dynamical behavior of the modified model has been investigated. We have demonstrated the analytical results by numerical analysis by taking some simulated set of parameter values.

  17. Finite difference modeling of sinking stage curved beam based on revised Vlasov equations

    Institute of Scientific and Technical Information of China (English)

    张磊; 朱真才; 沈刚; 曹国华

    2015-01-01

    For the static analysis of the sinking stage curved beam, a finite difference model was presented based on the proposed revised Vlasov equations. First, revised Vlasov equations for thin-walled curved beams with closed sections were deduced considering the shear strain on the mid-surface of the cross-section. Then, the finite difference formulation of revised Vlasov equations was implemented with the parabolic interpolation based on Taylor series. At last, the finite difference model was built by substituting geometry and boundary conditions of the sinking stage curved beam into the finite difference formulation. The validity of present work is confirmed by the published literature and ANSYS simulation results. It can be concluded that revised Vlasov equations are more accurate than the original one in the analysis of thin-walled beams with closed sections, and that present finite difference model is applicable in the evaluation of the sinking stage curved beam.

  18. The CSS and The Two-Staged Methods for Parameter Estimation in SARFIMA Models

    Directory of Open Access Journals (Sweden)

    Erol Egrioglu

    2011-01-01

    Full Text Available Seasonal Autoregressive Fractionally Integrated Moving Average (SARFIMA models are used in the analysis of seasonal long memory-dependent time series. Two methods, which are conditional sum of squares (CSS and two-staged methods introduced by Hosking (1984, are proposed to estimate the parameters of SARFIMA models. However, no simulation study has been conducted in the literature. Therefore, it is not known how these methods behave under different parameter settings and sample sizes in SARFIMA models. The aim of this study is to show the behavior of these methods by a simulation study. According to results of the simulation, advantages and disadvantages of both methods under different parameter settings and sample sizes are discussed by comparing the root mean square error (RMSE obtained by the CSS and two-staged methods. As a result of the comparison, it is seen that CSS method produces better results than those obtained from the two-staged method.

  19. Sugary Drink Warnings Hit Home with Teens

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160860.html Sugary Drink Warnings Hit Home With Teens Fewer choose sweetened ... Health warning labels can steer teens away from sugary drinks, a new study suggests. "The average teen in ...

  20. Joint Typhoon Warning Center (JTWC) Storm Wallets

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Joint Typhoon Warning Center (JTWC) is responsible for typhoon forecasts and warnings for the Western Pacific and Indian Ocean basins. After each storm, the JTWC...

  1. 基于向量自回归模型的中国食物安全预警%China’s food security and early-warning system based on vector autoregression (VAR) model

    Institute of Scientific and Technical Information of China (English)

    吕新业

    2013-01-01

      该文基于1980-2011年的人均粮食、禽蛋、肉类和水产品的产量和消费量数据,以及4类产品的价格指数数据,构建了中国食物安全预警的指标体系,运用向量自回归模型(VAR)对食物安全指标进行预测,再采用主成分法合成食物安全总指数,在此基础上对2012-2013年的食物安全状况进行预警分析。结果表明:基于1980-2011年的数据得到2012年和2013年的食物安全总指数分别为62和74。通过对2011年的预警值与实际值的比较,得到该预警模型的预测误差仅为4.2%,说明该模型系统的预测精度较高,可以用于未来中国食物安全预警研究。总体来看,2012-2013年中国食物安全状况为轻警。%Food safety pre-warning is the process including the application of the pre-warning theory and method, analysis and evaluation of relevant indicators reflecting food safety conditions, prediction of safety development and sounding the pre-warning. China’s food safety pre-warning supply derived from the study of China's grain security early warning system, which can be divided into a traditional warning model and a modern warning model. The traditional model is mainly based on the predictions of the trend of the grain production growth rate, predictions of grain supply and demand, predictions of grain staff indexes, predictions of grain fluctuation cycle, and predictions of prosperity. Based on China’s per capita production and consumption of grain, eggs, meat, aquaculture products, and the price indexes of these four types of products from 1980 to 2011, this study establishes the index for China’s food safety early-warning system. The Vector Autoregression Model (VAR) is used to predict China’s food safety indicators, and the Principal Component statistical method is used to synthesize the aggregated food safety index, and China’s food safety in 2012 and 2013 are projected. Specifically, this study

  2. TARGET ANALYSIS OF SUZHOU CREEK REHABILITATION PROJECT STAGE II:BASED ON WATER QUALITY MODEL

    Institute of Scientific and Technical Information of China (English)

    LIAO Zhen-liang; XU Zu-xin

    2004-01-01

    The Suzhou Creek is a seriously polluted tidal river in Shanghai. The Suzhou Creek Rehabilitation Project was launched in 1998, and the total investment will surpass 10 billion yuan RMB. It is important to assess the effectiveness of the project and ascertain its targets. In this study, by analyzing the achievements of Suzhou Creek Rehabilitation Project (Stage I) and its remaining problems, the main tasks of the Project Stage II are proposed. These works are wastewater interception, sediment dredging, bidirectional water diversion, and reconstruction of municipal pump stations. The water quality model established with USEPA's WASP is employed to analyze the quantitative targets of the Project Stage II. In the Project Stage II, the water quality of mainstream and tributaries will be improved continuously, the valus of CODCr, BOD5, DO in the mainstream will steadily attain Class IV according to the National Surface Water Quality Standard, and the ecological environment of Suzhou Creek with continuously recover.

  3. A three-stage stochastic optimization model for the Brazilian biodiesel supply chain

    Directory of Open Access Journals (Sweden)

    Pedro Senna

    2016-01-01

    Full Text Available Abstract The Brazilian program for biodiesel use highlights the production of biodiesel from castor seeds. Biodiesel is a non-polluting energy source that has the potential to promote prosperity by creating jobs in poor regions of Brazil. However, the infrastructure, logistics, and proper facilities are lacking. A variety of approaches to optimizing the biodiesel supply chain have been proposed. The goal is to minimize the grain storage and transportation costs. This paper presents a comparison between a two-stage model and a multistage (three-stage stochastic model to optimize the biodiesel supply chain. The comparison between these formulations shows that the flexibility gain provided by the multistage model results in a lower total logistic cost. The optimum for the three-stage model was 7,700,019 (BRL, compared to 8,628,002 (BRL for the two-stage model, representing a savings of 927,983 (BRL. We highlight that this model offers a real solution for castor supply chain design (considering uncertainty in the Brazilian semiarid region, which is a poorer region of the country, thus making cost reduction mandatory.

  4. Autobiography and Anorexia: A Qualitative Alternative to Prochaska and DiClemente's Stages of Change Model

    OpenAIRE

    Félix Díaz; Natalia Solano Pinto; Irene Solbes

    2012-01-01

    In this article, we propose a qualitative approach to the study of the ways in which people face good and poor health issues. During the last 30 years, Prochaska and DiClemente's "trans-theoretical model" (1982, 1983, 1984, 1986, 1992) has gained relevance as a model to assess disposition for change in patients. We revise the features of the model and its common techniques to assess stages of change, underlining its methodological and conceptual problems. Particularly, we discuss the paradoxe...

  5. Analysis and modeling of infrasound from a four-stage rocket launch.

    Science.gov (United States)

    Blom, Philip; Marcillo, Omar; Arrowsmith, Stephen

    2016-06-01

    Infrasound from a four-stage sounding rocket was recorded by several arrays within 100 km of the launch pad. Propagation modeling methods have been applied to the known trajectory to predict infrasonic signals at the ground in order to identify what information might be obtained from such observations. There is good agreement between modeled and observed back azimuths, and predicted arrival times for motor ignition signals match those observed. The signal due to the high-altitude stage ignition is found to be low amplitude, despite predictions of weak attenuation. This lack of signal is possibly due to inefficient aeroacoustic coupling in the rarefied upper atmosphere.

  6. Demonstration of the Cascadia G‐FAST geodetic earthquake early warning system for the Nisqually, Washington, earthquake

    Science.gov (United States)

    Crowell, Brendan; Schmidt, David; Bodin, Paul; Vidale, John; Gomberg, Joan S.; Hartog, Renate; Kress, Victor; Melbourne, Tim; Santillian, Marcelo; Minson, Sarah E.; Jamison, Dylan

    2016-01-01

    A prototype earthquake early warning (EEW) system is currently in development in the Pacific Northwest. We have taken a two‐stage approach to EEW: (1) detection and initial characterization using strong‐motion data with the Earthquake Alarm Systems (ElarmS) seismic early warning package and (2) the triggering of geodetic modeling modules using Global Navigation Satellite Systems data that help provide robust estimates of large‐magnitude earthquakes. In this article we demonstrate the performance of the latter, the Geodetic First Approximation of Size and Time (G‐FAST) geodetic early warning system, using simulated displacements for the 2001Mw 6.8 Nisqually earthquake. We test the timing and performance of the two G‐FAST source characterization modules, peak ground displacement scaling, and Centroid Moment Tensor‐driven finite‐fault‐slip modeling under ideal, latent, noisy, and incomplete data conditions. We show good agreement between source parameters computed by G‐FAST with previously published and postprocessed seismic and geodetic results for all test cases and modeling modules, and we discuss the challenges with integration into the U.S. Geological Survey’s ShakeAlert EEW system.

  7. On the use of Bayesian decision theory for issuing natural hazard warnings.

    Science.gov (United States)

    Economou, T; Stephenson, D B; Rougier, J C; Neal, R A; Mylne, K R

    2016-10-01

    Warnings for natural hazards improve societal resilience and are a good example of decision-making under uncertainty. A warning system is only useful if well defined and thus understood by stakeholders. However, most operational warning systems are heuristic: not formally or transparently defined. Bayesian decision theory provides a framework for issuing warnings under uncertainty but has not been fully exploited. Here, a decision theoretic framework is proposed for hazard warnings. The framework allows any number of warning levels and future states of nature, and a mathematical model for constructing the necessary loss functions for both generic and specific end-users is described. The approach is illustrated using one-day ahead warnings of daily severe precipitation over the UK, and compared to the current decision tool used by the UK Met Office. A probability model is proposed to predict precipitation, given ensemble forecast information, and loss functions are constructed for two generic stakeholders: an end-user and a forecaster. Results show that the Met Office tool issues fewer high-level warnings compared with our system for the generic end-user, suggesting the former may not be suitable for risk averse end-users. In addition, raw ensemble forecasts are shown to be unreliable and result in higher losses from warnings.

  8. On the use of Bayesian decision theory for issuing natural hazard warnings

    Science.gov (United States)

    Economou, T.; Stephenson, D. B.; Rougier, J. C.; Neal, R. A.; Mylne, K. R.

    2016-10-01

    Warnings for natural hazards improve societal resilience and are a good example of decision-making under uncertainty. A warning system is only useful if well defined and thus understood by stakeholders. However, most operational warning systems are heuristic: not formally or transparently defined. Bayesian decision theory provides a framework for issuing warnings under uncertainty but has not been fully exploited. Here, a decision theoretic framework is proposed for hazard warnings. The framework allows any number of warning levels and future states of nature, and a mathematical model for constructing the necessary loss functions for both generic and specific end-users is described. The approach is illustrated using one-day ahead warnings of daily severe precipitation over the UK, and compared to the current decision tool used by the UK Met Office. A probability model is proposed to predict precipitation, given ensemble forecast information, and loss functions are constructed for two generic stakeholders: an end-user and a forecaster. Results show that the Met Office tool issues fewer high-level warnings compared with our system for the generic end-user, suggesting the former may not be suitable for risk averse end-users. In addition, raw ensemble forecasts are shown to be unreliable and result in higher losses from warnings.

  9. 30 CFR 56.14208 - Warning devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Warning devices. 56.14208 Section 56.14208 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Safety Practices and Operational Procedures § 56.14208 Warning devices. (a) Visible warning devices...

  10. 30 CFR 57.14208 - Warning devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Warning devices. 57.14208 Section 57.14208... Equipment Safety Practices and Operational Procedures § 57.14208 Warning devices. (a) Visible warning devices shall be used when parked mobile equipment creates a hazard to persons in other mobile...

  11. 30 CFR 57.14214 - Train warnings.

    Science.gov (United States)

    2010-07-01

    ... Equipment Safety Practices and Operational Procedures § 57.14214 Train warnings. A warning that is audible above the surrounding noise level shall be sounded— (a) Immediately prior to moving trains; (b) When... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Train warnings. 57.14214 Section...

  12. 30 CFR 56.14214 - Train warnings.

    Science.gov (United States)

    2010-07-01

    ... Safety Practices and Operational Procedures § 56.14214 Train warnings. A warning that is audible above the surrounding noise level shall be sounded— (a) Immediately prior to moving trains; (b) When trains... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Train warnings. 56.14214 Section...

  13. 基于极大熵投影寻踪组合法的水资源预警评价模型%Warning Evaluation Model of Water Resources Based on Set of Legal Projection Pursuit of the Maximum Entropy

    Institute of Scientific and Technical Information of China (English)

    任永泰; 李丽

    2011-01-01

    利用基于极大熵准则赋权和基于实数加速遗传算法的投影寻踪方法相结合的组合附权法确定了各预警指标的权重;采用层次分析法计算水资源可持续利用复合系统中各子系统所占权重;利用综合评价模型计算出哈尔滨市水资源可持续发展指数;最终得到哈尔滨市水资源可持续利用预警结果.%The weights of each warning index are determined by combination enables law which is based on the maximum entropy criterion empowerment and projection pursuit method of real accelerating genetic algorithm; Using analytic hierarchy process to calculate the weights of each subsystem in composite system of water resources sustainable utilization; Sustainable development index of Harbin water resources is calculated by using comprehensive evaluation model; Warning results of Harbin water resources sustainable utilization are got eventually.

  14. 无人机警戒雷达仿真系统的建模与仿真%Research on Modeling and Simulation of UAV Warning Radar

    Institute of Scientific and Technical Information of China (English)

    张耀中; 张建东; 史国庆

    2016-01-01

    针对海面静止和移动目标的探测、感知、识别、成像等问题,建立了由数据/控制接口、人机界面及多个算法模块组成的无人机警戒雷达仿真系统。系统采用模块化方法对目标运动特性、环境特性和警戒雷达的功能特性进行建模与仿真,主要用于模拟现实装备中此类载荷的基本功能,从数字化仿真层面实现了无人机警戒雷达载荷功能的再现与性能测试,并能完成与指挥控制台之间的信息交互,同时系统具有很好的可扩展性,可以作为整个作战仿真系统的一部分,嵌入到更复杂的作战仿真系统中。%For the stationary and moving target detection,awareness,recognition,imaging and other issues in the sea environment,the simulation system of UAV warning radar which is composed of the data/control interface,human-machine interface and other function algorithm modules is designed. In the simulation system modular approach for the target movement characteristics,environmental characteristics and feature functions of the warning radar,which mainly used to simulating the basic functions of the real equipment are adopted. The feature function and performance testing of UAV warning radar from the digital level is realized. Our simulation system can interchange information with the command console via the Ethernet bus. At the same time,the system has good scalability,which can be used as part of the whole combat simulation system.

  15. Key Parameters Estimation and Adaptive Warning Strategy for Rear-End Collision of Vehicle

    Directory of Open Access Journals (Sweden)

    Xiang Song

    2015-01-01

    Full Text Available The rear-end collision warning system requires reliable warning decision mechanism to adapt the actual driving situation. To overcome the shortcomings of existing warning methods, an adaptive strategy is proposed to address the practical aspects of the collision warning problem. The proposed strategy is based on the parameter-adaptive and variable-threshold approaches. First, several key parameter estimation algorithms are developed to provide more accurate and reliable information for subsequent warning method. They include a two-stage algorithm which contains a Kalman filter and a Luenberger observer for relative acceleration estimation, a Bayesian theory-based algorithm of estimating the road friction coefficient, and an artificial neural network for estimating the driver’s reaction time. Further, the variable-threshold warning method is designed to achieve the global warning decision. In the method, the safety distance is employed to judge the dangerous state. The calculation method of the safety distance in this paper can be adaptively adjusted according to the different driving conditions of the leading vehicle. Due to the real-time estimation of the key parameters and the adaptive calculation of the warning threshold, the strategy can adapt to various road and driving conditions. Finally, the proposed strategy is evaluated through simulation and field tests. The experimental results validate the feasibility and effectiveness of the proposed strategy.

  16. Impact of social preparedness on flood early warning systems

    Science.gov (United States)

    Girons Lopez, M.; Di Baldassarre, G.; Seibert, J.

    2017-01-01

    Flood early warning systems play a major role in the disaster risk reduction paradigm as cost-effective methods to mitigate flood disaster damage. The connections and feedbacks between the hydrological and social spheres of early warning systems are increasingly being considered as key aspects for successful flood mitigation. The behavior of the public and first responders during flood situations, determined by their preparedness, is heavily influenced by many behavioral traits such as perceived benefits, risk awareness, or even denial. In this study, we use the recency of flood experiences as a proxy for social preparedness to assess its impact on the efficiency of flood early warning systems through a simple stylized model and implemented this model using a simple mathematical description. The main findings, which are based on synthetic data, point to the importance of social preparedness for flood loss mitigation, especially in circumstances where the technical forecasting and warning capabilities are limited. Furthermore, we found that efforts to promote and preserve social preparedness may help to reduce disaster-induced losses by almost one half. The findings provide important insights into the role of social preparedness that may help guide decision-making in the field of flood early warning systems.

  17. Towards a Humanized Mouse Model of Liver Stage Malaria Using Ectopic Artificial Livers

    Science.gov (United States)

    Ng, Shengyong; March, Sandra; Galstian, Ani; Gural, Nil; Stevens, Kelly R.; Mota, Maria M.; Bhatia, Sangeeta N.

    2017-01-01

    The malaria liver stage is an attractive target for antimalarial development, and preclinical malaria models are essential for testing such candidates. Given ethical concerns and costs associated with non‐human primate models, humanized mouse models containing chimeric human livers offer a valuable alternative as small animal models of liver stage human malaria. The best available human liver chimeric mice rely on cellular transplantation into mice with genetically engineered liver injury, but these systems involve a long and variable humanization process, are expensive, and require the use of breeding-challenged mouse strains which are not widely accessible. We previously incorporated primary human hepatocytes into engineered polyethylene glycol (PEG)-based nanoporous human ectopic artificial livers (HEALs), implanted them in mice without liver injury, and rapidly generated human liver chimeric mice in a reproducible and scalable fashion. By re-designing the PEG scaffold to be macroporous, we demonstrate the facile fabrication of implantable porous HEALs that support liver stage human malaria (P. falciparum) infection in vitro, and also after implantation in mice with normal liver function, 60% of the time. This proof-of-concept study demonstrates the feasibility of applying a tissue engineering strategy towards the development of scalable preclinical models of liver stage malaria infection for future applications. PMID:28361899

  18. A two-stage cascade model of BOLD responses in human visual cortex.

    Directory of Open Access Journals (Sweden)

    Kendrick N Kay

    Full Text Available Visual neuroscientists have discovered fundamental properties of neural representation through careful analysis of responses to controlled stimuli. Typically, different properties are studied and modeled separately. To integrate our knowledge, it is necessary to build general models that begin with an input image and predict responses to a wide range of stimuli. In this study, we develop a model that accepts an arbitrary band-pass grayscale image as input and predicts blood oxygenation level dependent (BOLD responses in early visual cortex as output. The model has a cascade architecture, consisting of two stages of linear and nonlinear operations. The first stage involves well-established computations-local oriented filters and divisive normalization-whereas the second stage involves novel computations-compressive spatial summation (a form of normalization and a variance-like nonlinearity that generates selectivity for second-order contrast. The parameters of the model, which are estimated from BOLD data, vary systematically across visual field maps: compared to primary visual cortex, extrastriate maps generally have larger receptive field size, stronger levels of normalization, and increased selectivity for second-order contrast. Our results provide insight into how stimuli are encoded and transformed in successive stages of visual processing.

  19. A two-stage broadcast message propagation model in social networks

    Science.gov (United States)

    Wang, Dan; Cheng, Shun-Jun

    2016-11-01

    Message propagation in social networks is becoming a popular topic in complex networks. One of the message types in social networks is called broadcast message. It refers to a type of message which has a unique and unknown destination for the publisher, such as 'lost and found'. Its propagation always has two stages. Due to this feature, rumor propagation model and epidemic propagation model have difficulty in describing this message's propagation accurately. In this paper, an improved two-stage susceptible-infected-removed model is proposed. We come up with the concept of the first forwarding probability and the second forwarding probability. Another part of our work is figuring out the influence to the successful message transmission chance in each level resulting from multiple reasons, including the topology of the network, the receiving probability, the first stage forwarding probability, the second stage forwarding probability as well as the length of the shortest path between the publisher and the relevant destination. The proposed model has been simulated on real networks and the results proved the model's effectiveness.

  20. Dynamics Analysis of an HIV Infection Model including Infected Cells in an Eclipse Stage

    Directory of Open Access Journals (Sweden)

    Shengyu Zhou

    2013-01-01

    Full Text Available In this paper, an HIV infection model including an eclipse stage of infected cells is considered. Some quicker cells in this stage become productively infected cells, a portion of these cells are reverted to the uninfected class, and others will be latent down in the body. We consider CTL-response delay in this model and analyze the effect of time delay on stability of equilibrium. It is shown that the uninfected equilibrium and CTL-absent infection equilibrium are globally asymptotically stable for both ODE and DDE model. And we get the global stability of the CTL-present equilibrium for ODE model. For DDE model, we have proved that the CTL-present equilibrium is locally asymptotically stable in a range of delays and also have studied the existence of Hopf bifurcations at the CTL-present equilibrium. Numerical simulations are carried out to support our main results.

  1. Diagnosis and Early Warning of Wind Turbine Faults Based on Cluster Analysis Theory and Modified ANFIS

    Directory of Open Access Journals (Sweden)

    Quan Zhou

    2017-07-01

    Full Text Available The construction of large-scale wind farms results in a dramatic increase of wind turbine (WT faults. The failure mode is also becoming increasingly complex. This study proposes a new model for early warning and diagnosis of WT faults to solve the problem of Supervisory Control And Data Acquisition (SCADA systems, given that the traditional threshold method cannot provide timely warning. First, the characteristic quantity of fault early warning and diagnosis analyzed by clustering analysis can obtain in advance abnormal data in the normal threshold range by considering the effects of wind speed. Based on domain knowledge, Adaptive Neuro-fuzzy Inference System (ANFIS is then modified to establish the fault early warning and diagnosis model. This approach improves the accuracy of the model under the condition of absent and sparse training data. Case analysis shows that the effect of the early warning and diagnosis model in this study is better than that of the traditional threshold method.

  2. Stages of decompensation in combat-related posttraumatic stress disorder: a new conceptual model.

    Science.gov (United States)

    Wang, S; Wilson, J P; Mason, J W

    1996-01-01

    This conceptual article presents a model of severe, chronic combat-related PTSD based on several years of longitudinal clinical observations of Vietnam veterans. The model describes a repeating cycle of decompensation that profoundly disrupts the veteran's life. There appear to be "stages" of decompensation that can be described clinically and may be distinct physiologically. The stages describe a wide range of functioning, from adaptive to totally dysfunctional PTSD core symptoms, as well as several other dimensions of clinical functioning, such as affect regulation, defenses, ego states, interactions with the environment, capacity for self-destruction/suicide and capacity for attachment and insight are described for each stage. Clinical and research implications are discussed.

  3. A Novel Kinetic Model of Liquid Nitrogen's Explosive Boiling at the Initial Stage

    Institute of Scientific and Technical Information of China (English)

    HUAI Xiu-Lan; DONG Zhao-Yi; LI Zhi-Gang; YIN Tie-Nan; ZOU Yu

    2007-01-01

    The liquid nitrogen's explosive boiling characteristics under transient high heat flux have attracted increasing attentions of researchers over the world due to its wide applications. Although some experiments have been performed, the process and the characteristics at the initial stage, especially within 1μs, have not been described reasonably yet. Based on the related experiments and theoretical analysis, a novel kinetic model combined with quasi-fluid idea is presented to analyse the characteristics of liquid nitrogen's explosive boiling at the initial stage. The results indicate that the model can appropriately describe the liquid nitrogen's explosive boiling. The behaviour and the heat transfer characteristics of a single bubble are very different from those of the bubble cluster, thus the behaviour of individual bubbles could not be directly applied to describe the explosive boiling process at the initial stage.

  4. Wavelet analysis of the seismograms for tsunami warning

    Directory of Open Access Journals (Sweden)

    A. Chamoli

    2010-10-01

    Full Text Available The complexity in the tsunami phenomenon makes the available warning systems not much effective in the practical situations. The problem arises due to the time lapsed in the data transfer, processing and modeling. The modeling and simulation needs the input fault geometry and mechanism of the earthquake. The estimation of these parameters and other aprior information increases the utilized time for making any warning. Here, the wavelet analysis is used to identify the tsunamigenesis of an earthquake. The frequency content of the seismogram in time scale domain is examined using wavelet transform. The energy content in high frequencies is calculated and gives a threshold for tsunami warnings. Only first few minutes of the seismograms of the earthquake events are used for quick estimation. The results for the earthquake events of Andaman Sumatra region and other historic events are promising.

  5. Dynamic models of staged gasification processes. Documentation of gasification simulator; Dynamiske modeller a f trinopdelte forgasningsprocesser. Dokumentation til forgasser simulator

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-02-15

    In connection with the ERP project 'Dynamic modelling of staged gasification processes' a gasification simulator has been constructed. The simulator consists of: a mathematical model of the gasification process developed at Technical University of Denmark, a user interface programme, IGSS, and a communication interface between the two programmes. (BA)

  6. POT Early-Warning Model of Dam Based on Game Theory and its Application%基于博弈论的大坝POT预警模型及其应用

    Institute of Scientific and Technical Information of China (English)

    谢珊珊; 周衡

    2016-01-01

    A model based on Game Theory and POT model has been established to determine warming index of concrete dam. The Game The⁃ory was applied to determine the comprehensive index weight and then the deformation entropy of multi measured point was established based on entropy theory. The POT model in Extreme Value Theory was introduced to implement the early⁃warning index estimation, according to the threshold, the analysis samples were obtained from the deformation entropy data exceeding the threshold, which satisfied the generalized Pa⁃reto Distribution. The generalized Pareto Distribution function of the data exceeding the threshold was determined. The early⁃warning index could be calculated by the combination of above distribution function and the dam failure probability. Finally, a certain concrete dam in Ya⁃long River was used as the modeling object and the result indicates that the obtained early⁃warning index can describe objectively the actual status of dam engineering.%引入极值理论,提出了基于博弈论的POT变形预警模型。对于多测点原型观测数据,以博弈论确定其综合权重,以信息熵理论构建多测点的变形熵,通过POT模型设置一定的阈值,选取变形熵的超限值作为建模对象,利用广义帕累托分布拟合超限数据子样,以失效概率给出其变形预警值。将该方法用于雅砻江流域某混凝土拱坝的大坝预警实践,结果表明,与传统的单测点处理方法相比,该模型可以得出更加合理的结果,更能反映工程实际。

  7. What makes us think? A three-stage dual-process model of analytic engagement.

    Science.gov (United States)

    Pennycook, Gordon; Fugelsang, Jonathan A; Koehler, Derek J

    2015-08-01

    The distinction between intuitive and analytic thinking is common in psychology. However, while often being quite clear on the characteristics of the two processes ('Type 1' processes are fast, autonomous, intuitive, etc. and 'Type 2' processes are slow, deliberative, analytic, etc.), dual-process theorists have been heavily criticized for being unclear on the factors that determine when an individual will think analytically or rely on their intuition. We address this issue by introducing a three-stage model that elucidates the bottom-up factors that cause individuals to engage Type 2 processing. According to the model, multiple Type 1 processes may be cued by a stimulus (Stage 1), leading to the potential for conflict detection (Stage 2). If successful, conflict detection leads to Type 2 processing (Stage 3), which may take the form of rationalization (i.e., the Type 1 output is verified post hoc) or decoupling (i.e., the Type 1 output is falsified). We tested key aspects of the model using a novel base-rate task where stereotypes and base-rate probabilities cued the same (non-conflict problems) or different (conflict problems) responses about group membership. Our results support two key predictions derived from the model: (1) conflict detection and decoupling are dissociable sources of Type 2 processing and (2) conflict detection sometimes fails. We argue that considering the potential stages of reasoning allows us to distinguish early (conflict detection) and late (decoupling) sources of analytic thought. Errors may occur at both stages and, as a consequence, bias arises from both conflict monitoring and decoupling failures.

  8. Two-stage residual inclusion estimation: addressing endogeneity in health econometric modeling.

    Science.gov (United States)

    Terza, Joseph V; Basu, Anirban; Rathouz, Paul J

    2008-05-01

    The paper focuses on two estimation methods that have been widely used to address endogeneity in empirical research in health economics and health services research-two-stage predictor substitution (2SPS) and two-stage residual inclusion (2SRI). 2SPS is the rote extension (to nonlinear models) of the popular linear two-stage least squares estimator. The 2SRI estimator is similar except that in the second-stage regression, the endogenous variables are not replaced by first-stage predictors. Instead, first-stage residuals are included as additional regressors. In a generic parametric framework, we show that 2SRI is consistent and 2SPS is not. Results from a simulation study and an illustrative example also recommend against 2SPS and favor 2SRI. Our findings are important given that there are many prominent examples of the application of inconsistent 2SPS in the recent literature. This study can be used as a guide by future researchers in health economics who are confronted with endogeneity in their empirical work.

  9. Incorporating Hydroepidemiology into the Epidemia Malaria Early Warning System

    Science.gov (United States)

    Wimberly, M. C.; Merkord, C. L.; Henebry, G. M.; Senay, G. B.

    2014-12-01

    Early warning of the timing and locations of malaria epidemics can facilitate the targeting of resources for prevention and emergency response. In response to this need, we are developing the Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessment (EPIDEMIA) computer system. EPIDEMIA incorporates software for capturing, processing, and integrating environmental and epidemiological data from multiple sources; data assimilation techniques that continually update models and forecasts; and a web-based interface that makes the resulting information available to public health decision makers. The system will enable forecasts that incorporate lagged responses to environmental risk factors as well as information about recent trends in malaria cases. Because the egg, larval, and pupal stages of mosquito development occur in aquatic habitats, information about the spatial and temporal distributions of stagnant water bodies is critical for modeling malaria risk. Potential sources of hydrological data include satellite-derived rainfall estimates, evapotranspiration (ET) calculated using a simplified surface energy balance model, and estimates of soil moisture and fractional water cover from passive microwave radiometry. We used partial least squares regression to analyze and visualize seasonal patterns of these variables in relation to malaria cases using data from 49 districts in the Amhara region of Ethiopia. Seasonal patterns of rainfall were strongly associated with the incidence and seasonality of malaria across the region, and model fit was improved by the addition of remotely-sensed ET and soil moisture variables. The results highlight the importance of remotely-sensed hydrological data for modeling malaria risk in this region and emphasize the value of an ensemble approach that utilizes multiple sources of information about precipitation and land surface wetness. These variables will be incorporated into the forecasting models at

  10. Prediction of Pathological Stage in Patients with Prostate Cancer: A Neuro-Fuzzy Model.

    Directory of Open Access Journals (Sweden)

    Georgina Cosma

    Full Text Available The prediction of cancer staging in prostate cancer is a process for estimating the likelihood that the cancer has spread before treatment is given to the patient. Although important for determining the most suitable treatment and optimal management strategy for patients, staging continues to present significant challenges to clinicians. Clinical test results such as the pre-treatment Prostate-Specific Antigen (PSA level, the biopsy most common tumor pattern (Primary Gleason pattern and the second most common tumor pattern (Secondary Gleason pattern in tissue biopsies, and the clinical T stage can be used by clinicians to predict the pathological stage of cancer. However, not every patient will return abnormal results in all tests. This significantly influences the capacity to effectively predict the stage of prostate cancer. Herein we have developed a neuro-fuzzy computational intelligence model for classifying and predicting the likelihood of a patient having Organ-Confined Disease (OCD or Extra-Prostatic Disease (ED using a prostate cancer patient dataset obtained from The Cancer Genome Atlas (TCGA Research Network. The system input consisted of the following variables: Primary and Secondary Gleason biopsy patterns, PSA levels, age at diagnosis, and clinical T stage. The performance of the neuro-fuzzy system was compared to other computational intelligence based approaches, namely the Artificial Neural Network, Fuzzy C-Means, Support Vector Machine, the Naive Bayes classifiers, and also the AJCC pTNM Staging Nomogram which is commonly used by clinicians. A comparison of the optimal Receiver Operating Characteristic (ROC points that were identified using these approaches, revealed that the neuro-fuzzy system, at its optimal point, returns the largest Area Under the ROC Curve (AUC, with a low number of false positives (FPR = 0.274, TPR = 0.789, AUC = 0.812. The proposed approach is also an improvement over the AJCC pTNM Staging Nomogram (FPR

  11. Approximate queueing models for capacitated multi-stage inventory systems under base-stock control

    NARCIS (Netherlands)

    Avsar, Zeynep Müge; Zijm, Willem H.M.

    2014-01-01

    A queueing analysis is presented for base-stock controlled multi-stage production-inventory systems with capacity constraints. The exact queueing model is approximated by replacing some state-dependent conditional probabilities (that are used to express the transition rates) by constants. Two

  12. Realizing joined-up government: Dynamic capabilities and stage models for transformation

    NARCIS (Netherlands)

    Klievink, B.; Janssen, M.

    2009-01-01

    Joining up remains a high priority on the e-government agenda and requires extensive transformation. Stage models are predictable patterns which exist in the growth of organizations and unfold as discrete time periods that result in discontinuity and can help e-government development towards joined-

  13. Using Five Stage Model to Design of Collaborative Learning Environments in Second Life

    Science.gov (United States)

    Orhan, Sevil; Karaman, M. Kemal

    2014-01-01

    Specifically Second Life (SL) among virtual worlds draws attention of researchers to form collaborative learning environments (Sutcliffe & Alrayes, 2012) since it could be used as a rich platform to simulate a real environment containing many collaborative learning characteristics and interaction tools within itself. Five Stage Model (FSM)…

  14. Periodic Solutions of a Delayed Predator-Prey Model with Stage Structure for Prey

    Institute of Scientific and Technical Information of China (English)

    Rui Xu; Lan-sun Chen; Fei-long Hao

    2004-01-01

    A periodic predator-prey model with stage structure for prey and time delays due to negative feedbackand gestation of predator is proposed. By using Gaines and Mawhin's continuation theorem of coincidencedegree theory, su.cient conditions are derived for the existence of positive periodic solutions to the proposedmodel. Numerical simulations are presented to illustrate the feasibility of our main result.

  15. PERIODIC SOLUTION AND ALMOST PERIODIC SOLUTION OF NONAUTONOMOUS COMPETITIVE MODEL WITH STAGE STRUCTURE AND HARVESTING

    Institute of Scientific and Technical Information of China (English)

    YaoZhijian

    2005-01-01

    In this paper, a two-species nonautonomous competitive model with stage structure and harvesting is considered. Sufficient conditions for the existence, uniqueness, global attractivity of positive periodic solution and the existence, uniform asvmntotic stability of almost neriodic solution are obtained.

  16. Wallas' Four-Stage Model of the Creative Process: More than Meets the Eye?

    Science.gov (United States)

    Sadler-Smith, Eugene

    2015-01-01

    Based on a detailed reading of Graham Wallas' "Art of Thought" (1926) it is argued that his four-stage model of the creative process (Preparation, Incubation, Illumination, Verification), in spite of holding sway as a conceptual anchor for many creativity researchers, does not reflect accurately Wallas' full account of the creative…

  17. ADM1-based modeling of methane production from acidified sweet sorghum extractin a two stage process

    DEFF Research Database (Denmark)

    Antonopoulou, Georgia; Gavala, Hariklia N.; Skiadas, Ioannis

    2012-01-01

    The present study focused on the application of the Anaerobic Digestion Model 1 οn the methane production from acidified sorghum extract generated from a hydrogen producing bioreactor in a two-stage anaerobic process. The kinetic parameters for hydrogen and volatile fatty acids consumption were...

  18. Bayesian Analysis for Linearized Multi-Stage Models in Quantal Bioassay.

    Science.gov (United States)

    Kuo, Lynn; Cohen, Michael P.

    Bayesian methods for estimating dose response curves in quantal bioassay are studied. A linearized multi-stage model is assumed for the shape of the curves. A Gibbs sampling approach with data augmentation is employed to compute the Bayes estimates. In addition, estimation of the "relative additional risk" and the "risk specific…

  19. Violent Victimization and Perpetration during Adolescence: Developmental Stage Dependent Ecological Models

    Science.gov (United States)

    Matjasko, Jennifer L.; Needham, Belinda L.; Grunden, Leslie N.; Farb, Amy Feldman

    2010-01-01

    Using a variant of the ecological-transactional model and developmental theories of delinquency on a nationally representative sample of adolescents, the current study explored the ecological predictors of violent victimization, perpetration, and both for three different developmental stages during adolescence. We examined the relative influence…

  20. Thermal modelling approaches to enable mitigation measures implementation for salmonid gravel stages in hydropeaking rivers

    Science.gov (United States)

    Casas-Mulet, R.; Alfredsen, K. T.

    2016-12-01

    The dewatering of salmon spawning redds can lead to early life stages mortality due to hydropeaking operations, with higher impact on the alevins stages as they have lower tolerance to dewatering than the eggs. Targeted flow-related mitigations measures can reduce such mortality, but it is essential to understand how hydropeaking change thermal regimes in rivers and may impact embryo development; only then optimal measures can be implemented at the right development stage. We present a set of experimental approaches and modelling tools for the estimation of hatch and swim-up dates based on water temperature data in the river Lundesokna (Norway). We identified critical periods for gravel-stages survival and through comparing hydropeaking vs unregulated thermal and hydrological regimes, we established potential flow-release measures to minimise mortality. Modelling outcomes were then used assess the cost-efficiency of each measure. The combinations of modelling tools used in this study were overall satisfactory and their application can be useful especially in systems where little field data is available. Targeted measures built on well-informed modelling approaches can be pre-tested based on their efficiency to mitigate dewatering effects vs. the hydropower system capacity to release or conserve water for power production. Overall, environmental flow releases targeting specific ecological objectives can provide better cost-effective options than conventional operational rules complying with general legislation.

  1. Analysing outsourcing policies in an asset management context: a six-stage model

    NARCIS (Netherlands)

    Schoenmaker, R.; Verlaan, J.G.

    2013-01-01

    Asset managers of civil infrastructure are increasingly outsourcing their maintenance. Whereas maintenance is a cyclic process, decisions to outsource decisions are often project-based, and confusing the discussion on the degree of outsourcing. This paper presents a six-stage model that facilitates

  2. Analysing outsourcing policies in an asset management context: a six-stage model

    NARCIS (Netherlands)

    Schoenmaker, R.; Verlaan, J.G.

    2013-01-01

    Asset managers of civil infrastructure are increasingly outsourcing their maintenance. Whereas maintenance is a cyclic process, decisions to outsource decisions are often project-based, and confusing the discussion on the degree of outsourcing. This paper presents a six-stage model that facilitates

  3. Integrative health care model for climacteric stage women: design of the intervention

    Directory of Open Access Journals (Sweden)

    Pérez-Cuevas Ricardo

    2011-02-01

    Full Text Available Abstract Background Climacteric stage women experience significant biological, psychological and social changes. With demographic changes being observed in the growing number of climacteric stage women in Mexico, it is important to improve their knowledge about the climacteric stage and its potential associated problems, encourage their participation in screening programs, and promote the acquisition of healthy lifestyles. At Mexican health care institutions the predominant health care model for climacteric stage women has a biomedical perspective. Medical doctors provide mostly curative services and have limited support from other health professionals. This study aims to design an integrative health care model (IHCM: bio-psycho-social, multidisciplinary and women-centered applicable in primary care services aimed at climacteric stage women. Methods/Design We present the design, inclusion criteria and detailed description of an IHCM. The IHCM consists of collaborative and coordinated provision of services by a health team, which is involves a family doctor, nurse, psychologist, and the woman herself. The health team promotes the empowerment of women through individual and group counseling on the climacteric stage and health related self-care. The intervention lasts three months followed by a three-month follow-up period to evaluate the effectiveness of the model. The effectiveness of the model will be evaluated through the following aspects: health-related quality of life (HR-QoL, empowerment, self-efficacy and knowledge regarding the climacteric stage and health-related self-care activities, use of screening services, and improvement in lifestyles (regular leisure time physical activity and healthy diet. Discussion Participation in preventive activities should be encouraged among women in Mexico. Designing and evaluating the effectiveness of an integrative health care model for women at the climacteric stage, based on the empowerment approach

  4. Application of Early Warning and New Drug Inventory Procurement Model in Pharmacy in Daily Work%药品库存预警和新型采购模式在药库日常工作中的应用

    Institute of Scientific and Technical Information of China (English)

    张景双; 郭妹

    2016-01-01

    Objective To standardize and simplify the traditional purchasing model,and make the inventory rational,we introduce pharmacy inventory alert and new procurement model.Methods Design the reasonable inventory warning initial parameters first,secondtly pharmacy personne do the division setting of initial parametersl according to the actual working situation,then establish early warning upper and lower inventory and drug procurement plan quantity calculation formula. So as to automaticaly generate single drug purchase plan to record,analysis,compare the indicators of drug inventory parameters and workload in the old and new work model.ResultsThe inventory supply of new warning and purchasing model is closer to the optimum inventory days than the traditional model,warehouse personnel spend less time to complete procurement plan,average booking time of single invoice and the number of single variety monthly booking are significantly reduced,the lack of medicine and inventory backlog of the traditional model is obviously more than the new work mode of procurement.Conclusion The new warning and purchasing model make pharmacy inventory days more reasonable,avoid the backlog of drugs and lack of medicine,reduce the human consumption,improve the work efficiency.%目的:引入药库库存预警及新型采购模式,规范和简化传统采购模式,使在库库存量合理化。方法设计合理库存预警初始参数,药库人员根据实际工作情况对初始参数进行二次分化设定,建立库存预警上下限,得出药品采购计划量计算公式,从而自动生成药品采购计划单,记录、分析、比较在新旧工作模式下药品库存参数指标和工作量指标的差异。结果库存预警和新型采购模式下库存天数比传统模式更接近最适库存天数;库房人员完成采购计划单时间、单张发票平均入账时间和单品种月均入账次数都减少;传统模式出现库存积压、缺药的情况

  5. Experimental and modeling study of a two-stage pilot scale high solid anaerobic digester system.

    Science.gov (United States)

    Yu, Liang; Zhao, Quanbao; Ma, Jingwei; Frear, Craig; Chen, Shulin

    2012-11-01

    This study established a comprehensive model to configure a new two-stage high solid anaerobic digester (HSAD) system designed for highly degradable organic fraction of municipal solid wastes (OFMSW). The HSAD reactor as the first stage was naturally separated into two zones due to biogas floatation and low specific gravity of solid waste. The solid waste was retained in the upper zone while only the liquid leachate resided in the lower zone of the HSAD reactor. Continuous stirred-tank reactor (CSTR) and advective-diffusive reactor (ADR) models were constructed in series to describe the whole system. Anaerobic digestion model No. 1 (ADM1) was used as reaction kinetics and incorporated into each reactor module. Compared with the experimental data, the simulation results indicated that the model was able to well predict the pH, volatile fatty acid (VFA) and biogas production.

  6. Travelling wave and convergence in stage-structured reaction-diffusion competitive models with nonlocal delays

    Energy Technology Data Exchange (ETDEWEB)

    Xu Rui [Department of Applied Mathematics, Xi' an Jiaotong University, Xi' an 710049 (China)]. E-mail: rxu88@yahoo.com.cn; Chaplain, M.A.J. [Department of Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); Davidson, F.A. [Department of Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom)

    2006-11-15

    In this paper, we first investigate a stage-structured competitive model with time delays, harvesting, and nonlocal spatial effect. By using an iterative technique recently developed by Wu and Zou (Wu J, Zou X. Travelling wave fronts of reaction-diffusion systems with delay. J Dynam Differen Equat 2001;13:651-87), sufficient conditions are established for the existence of travelling front solution connecting the two boundary equilibria in the case when there is no positive equilibrium. The travelling wave front corresponds to an invasion by a stronger species which drives the weaker species to extinction. Secondly, we consider a stage-structured competitive model with time delays and nonlocal spatial effect when the domain is finite. We prove the global stability of each of the nonnegative equilibria and demonstrate that the more complex model studied here admits three possible long term behaviors: coexistence, bistability and dominance as is the case for the standard Lotka-Voltera competitive model.

  7. 水动力学模型在佛山市内涝预警中的应用研究%Application Research of Flow Dynamics Model Used in Flood Early Warning of Foshan

    Institute of Scientific and Technical Information of China (English)

    杜文印; 李娜; 王静

    2012-01-01

      The two-dimensional unsteady flow dynamics model uses Saint-Venant equations for basic mathematical equation to simulate open channel flow law of motion. Taking Foshan City center as range of study, future short-term rainfall which is predicted is one of the input conditions. Combining with high precision GIS city map, underground drainage network data, freshwater river and outer river water level, pumping station operation and so on, the two-dimensional unsteady flow dynamics model is used to simulate the effect of city by storm. City rainstorm waterlogging models and urban waterlogging warning system are used for urban waterlogging warning. Through the real-time monitoring and management of hydrological information, rainstorm waterlogging simulation, flood warning, hazard mapping and GIS applications etc, it provides decision-making basis and technical support for flood control, waterlogging forecast and emergency dispatch in Foshan.%  二维非恒定流水动力学模型以圣维南方程组为基本数学方程模拟明渠水流运动规律。以佛山市中心城区为研究范围,将预测的未来短时降雨情况作为输入条件之一,结合城区高精度数字地图、地下排水管网资料、内河涌及外江水位、泵站调度等信息,运用二维非恒定流水动力学模型模拟城区受暴雨影响情况,将城区暴雨内涝模型和城市内涝预警系统应用于城市内涝预警。通过水情信息的实时监测与管理、暴雨内涝模拟、洪水预警、风险图制作及 GIS 应用等技术手段,为佛山市城区的防汛、内涝预警和应急调度提供决策依据和技术支持。

  8. Three Stage Maturity Model in SME’s towards Industry 4.0

    OpenAIRE

    Ganzarain, Jaione; Errasti, Nekane

    2016-01-01

    Purpose: To address the challenges regarding the concept of Industry 4.0 and the diversification methodology and based on the strategic guidance towards Industry 4.0, we propose a process model as a guiding framework for Industry 4.0 collaborative diversification vision, strategy and action building. In this paper we suggest a stage process model to guide and train companies to identify new opportunities for diversification within Industry 4.0. Systematically carrying out the s...

  9. Three Stage Maturity Model in SME’s towards Industry 4.0

    OpenAIRE

    Jaione Ganzarain; Nekane Errasti

    2016-01-01

    Purpose: To address the challenges regarding the concept of Industry 4.0 and the diversification methodology and based on the strategic guidance towards Industry 4.0, we propose a process model as a guiding framework for Industry 4.0 collaborative diversification vision, strategy and action building. In this paper we suggest a stage process model to guide and train companies to identify new opportunities for diversification within Industry 4.0. Systematically carrying out the s...

  10. Bifurcation analysis on a delayed SIS epidemic model with stage structure

    Directory of Open Access Journals (Sweden)

    Kejun Zhuang

    2007-05-01

    Full Text Available In this paper, a delayed SIS (Susceptible Infectious Susceptible model with stage structure is investigated. We study the Hopf bifurcations and stability of the model. Applying the normal form theory and the center manifold argument, we derive the explicit formulas determining the properties of the bifurcating periodic solutions. The conditions to guarantee the global existence of periodic solutions are established. Also some numerical simulations for supporting the theoretical are given.

  11. Analysis, Predictive Modeling and Hoisted Object Impact Control in Hydro-cylinder Stage- Switching

    Directory of Open Access Journals (Sweden)

    S. V. Kobyzev

    2016-01-01

    Full Text Available The paper considers a problem of dynamic impact of hoisting mechanisms, which are based on the multistage hydro-cylinders, on the hoisted object. Hydro-cylinders have high specific characteristics, but there are also some drawbacks. One of them is an impact at the beginning and at the end of hoist and in switching the stages. And in case of switching the stages under certain conditions the impact in nature can be a high impact impulse. The paper explores the impacts at the beginning of hoist and when switching the stages.Numerical modeling is assumed to be a method of study. To build a mathematical model the following factors have been considered: geometrical cylinder parameters, hydraulic liquid compressibility, and friction between cylinder elements. Elasticity of ground, elasticity of rod, and elasticity of cylinder walls have been ignored.The modeling results allowed us to reveal a hydraulic nature of the stage-switching impact, introduce a formula to estimate the impact impulse value, show the friction effect on the impact impulse value and give a proposal to use a counter-pressure chamber to eliminate the stage-switching impact. An expression for the optimal counter-pressure is presented.The results obtained can find application in designing the new and upgrading the existing hoisting multistage hydro-cylinder mechanisms to increase a hoisting speed and simultaneously eliminate the impact on hoisted object.Compared to existing papers in the field concerned, this one concentrates on revealing a specific hydraulic nature of the stage-switching impact, without regard to dynamics and elasticity of the hoisting mechanism parts other than the cylinder itself.The achieved results find confirmation when compared to the numerical and field data published by other authors.

  12. Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application

    Directory of Open Access Journals (Sweden)

    Zhanghua Lian

    2015-03-01

    Full Text Available Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs, but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time. In view of this, based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well, mechanical models were established for three working cases of multiple packer setting, open differential-pressure sliding sleeve, and open ball-injection sliding sleeve under a hold-down packer. Moreover, mathematical models were respectively built for the above three cases. According to the Lame formula and Von Mises stress calculation formula for the thick-walled cylinder in the theory of elastic mechanics, a mathematical model was also established to calculate the equivalent stress for tubing string safety evaluation when the fracturing string was under the combined action of inner pressure, external squeezing force and axial stress, and another mathematical model was built for the mechanical strength and safety evaluation of multi-stage fracturing strings. In addition, a practical software was developed for the mechanical safety evaluation of horizontal well multi-stage fracturing strings according to the mathematical model developed for the mechanical calculation of the multi-packer string in horizontal wells. The research results were applied and verified in a gas well of Tahe Oilfield in the Tarim Basin with excellent effects, providing a theoretical basis and a simple and reliable technical means for optimal design and safety evaluation of safe operational parameters of multi-stage fracturing strings in horizontal wells.

  13. Geo-hazards risk zonation and warning system based on GIS in Anshan City of Liaoning

    Institute of Scientific and Technical Information of China (English)

    Zhishuang YANG; Mao PAN; Xiaopeng WANG

    2006-01-01

    Debris flow and Karst collapse are the main parts of geological disasters in Anshan, which have affected on the construction and development of the social economy of Anshan. In order to enhance the studies of rules of disaster and give scientific estimation and alarm ahead of schedule warning, we established the warning system of Anshan and investigated the corresponding software, which are based on the deep discussions about the crisis estimation and methods of prediction of disasters. In this paper, the foundation of model used in estimating the alarm ahead of schedule for disaster and the methods of appraisal for the alarm ahead of schedule are discussed. This system for warning and evaluating is the combination of the models of warning and GIS flat roof, with so many virtues, such as complete functions, convenience, applicability, which has considered the output of data, analyses of space, chooses of model, output of production, report of information for warning and the statements and help of system.

  14. NOAA/West coast and Alaska Tsunami warning center Atlantic Ocean response criteria

    Science.gov (United States)

    Whitmore, P.; Refidaff, C.; Caropolo, M.; Huerfano-Moreno, V.; Knight, W.; Sammler, W.; Sandrik, A.

    2009-01-01

    West Coast/Alaska Tsunami Warning Center (WCATWC) response criteria for earthquakesoccurring in the Atlantic and Caribbean basins are presented. Initial warning center decisions are based on an earthquake's location, magnitude, depth, distance from coastal locations, and precomputed threat estimates based on tsunami models computed from similar events. The new criteria will help limit the geographical extent of warnings and advisories to threatened regions, and complement the new operational tsunami product suite. Criteria are set for tsunamis generated by earthquakes, which are by far the main cause of tsunami generation (either directly through sea floor displacement or indirectly by triggering of sub-sea landslides).The new criteria require development of a threat data base which sets warning or advisory zones based on location, magnitude, and pre-computed tsunami models. The models determine coastal tsunami amplitudes based on likely tsunami source parameters for a given event. Based on the computed amplitude, warning and advisory zones are pre-set.

  15. Women's steps of change and entry into drug abuse treatment. A multidimensional stages of change model.

    Science.gov (United States)

    Brown, V B; Melchior, L A; Panter, A T; Slaughter, R; Huba, G J

    2000-04-01

    The Transtheoretical, or Stages of Change Model, has been applied to the investigation of help-seeking related to a number of addictive behaviors. Overall, the model has shown to be very important in understanding the process of help-seeking. However, substance abuse rarely exists in isolation from other health, mental health, and social problems. The present work extends the original Stages of Change Model by proposing "Steps of Change" as they relate to entry into substance abuse treatment programs for women. Readiness to make life changes in four domains-domestic violence, HIV sexual risk behavior, substance abuse, and mental health-is examined in relation to entry into four substance abuse treatment modalities (12-step, detoxification, outpatient, and residential). The Steps of Change Model hypothesizes that help-seeking behavior of substance-abusing women may reflect a hierarchy of readiness based on the immediacy, or time urgency, of their treatment issues. For example, women in battering relationships may be ready to make changes to reduce their exposure to violence before admitting readiness to seek substance abuse treatment. The Steps of Change Model was examined in a sample of 451 women contacted through a substance abuse treatment-readiness program in Los Angeles, California. A series of logistic regression analyses predict entry into four separate treatment modalities that vary. Results suggest a multidimensional Stages of Change Model that may extend to other populations and to other types of help-seeking behaviors.

  16. Screening for a Chronic Disease: A Multiple Stage Duration Model with Partial Observability.

    Science.gov (United States)

    Mroz, Thomas A; Picone, Gabriel; Sloan, Frank; Yashkin, Arseniy P

    2016-08-01

    We estimate a dynamic multi-stage duration model to investigate how early detection of diabetes can delay the onset of lower extremity complications and death. We allow for partial observability of the disease stage, unmeasured heterogeneity, and endogenous timing of diabetes screening. Timely diagnosis appears important. We evaluate the effectiveness of two potential policies to reduce the monetary costs of frequent screening in terms of lost longevity. Compared to the status quo, the more restrictive policy yields an implicit value for an additional year of life of about $50,000, while the less restrictive policy implies a value of about $120,000.

  17. Bifurcations of a singular prey-predator economic model with time delay and stage structure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xue [Institute of Systems Science, Northeastern University, Shenyang, Liaoning 110004 (China); Key Laboratory of Integrated Automation of Process Industry (Northeastern Univ.), Ministry of Education, Shenyang, Liaoning 110004 (China)], E-mail: zhangxueer@gmail.com; Zhang Qingling [Institute of Systems Science, Northeastern University, Shenyang, Liaoning 110004 (China); Key Laboratory of Integrated Automation of Process Industry (Northeastern Univ.), Ministry of Education, Shenyang, Liaoning 110004 (China)], E-mail: qlzhang@mail.neu.edu.cn; Liu Chao [Institute of Systems Science, Northeastern University, Shenyang, Liaoning 110004 (China); Key Laboratory of Integrated Automation of Process Industry (Northeastern Univ.), Ministry of Education, Shenyang, Liaoning 110004 (China); Xiang Zhongyi [Department of Mathematics, Hubei University for Nationalities, Enshi, Hubei 445000 (China)

    2009-11-15

    This paper studies a singular prey-predator economic model with time delay and stage structure. Compared with other researches on dynamics of prey-predator population, this model is described by differential-algebraic equations due to economic factor. For zero economic profit, this model exhibits three bifurcational phenomena: transcritical bifurcation, Hopf bifurcation and singular induced bifurcation. For positive economic profit, the model undergoes a saddle-node bifurcation at critical value of positive economic profit, and the increase of delay destabilizes the positive equilibrium point of the system and bifurcates into small amplitude periodic solution. Finally, by using Matlab software, numerical simulations illustrate the effectiveness of the results.

  18. Application of Seismic Array Processing to Tsunami Early Warning

    Science.gov (United States)

    An, C.; Meng, L.

    2015-12-01

    Tsunami wave predictions of the current tsunami warning systems rely on accurate earthquake source inversions of wave height data. They are of limited effectiveness for the near-field areas since the tsunami waves arrive before data are collected. Recent seismic and tsunami disasters have revealed the need for early warning to protect near-source coastal populations. In this work we developed the basis for a tsunami warning system based on rapid earthquake source characterisation through regional seismic array back-projections. We explored rapid earthquake source imaging using onshore dense seismic arrays located at regional distances on the order of 1000 km, which provides faster source images than conventional teleseismic back-projections. We implement this method in a simulated real-time environment, and analysed the 2011 Tohoku earthquake rupture with two clusters of Hi-net stations in Kyushu and Northern Hokkaido, and the 2014 Iquique event with the Earthscope USArray Transportable Array. The results yield reasonable estimates of rupture area, which is approximated by an ellipse and leads to the construction of simple slip models based on empirical scaling of the rupture area, seismic moment and average slip. The slip model is then used as the input of the tsunami simulation package COMCOT to predict the tsunami waves. In the example of the Tohoku event, the earthquake source model can be acquired within 6 minutes from the start of rupture and the simulation of tsunami waves takes less than 2 min, which could facilitate a timely tsunami warning. The predicted arrival time and wave amplitude reasonably fit observations. Based on this method, we propose to develop an automatic warning mechanism that provides rapid near-field warning for areas of high tsunami risk. The initial focus will be Japan, Pacific Northwest and Alaska, where dense seismic networks with the capability of real-time data telemetry and open data accessibility, such as the Japanese HiNet (>800

  19. Enterprise Social Network Relationship Model for Crisis Early Warning Information Gathering%面向危机信息采集的企业人际网络关系模型构建

    Institute of Scientific and Technical Information of China (English)

    郑德俊; 汪社教

    2011-01-01

    指出依托社会人际网络理论指导建立便于进行危机信息采集的内外人际网络关系模型,将有助于提高危机预警信息管理的准确性和有效性。分析关系强度理论和结构洞理论与企业危机信息采集的关系,提出依托关系强度理论构建企业内部人际网络模型,依托结构洞理论构建企业外部人际关系网络模型;认为可以通过社会人际网络获取危机预警信息,同时社会人际网络可为企业危机信息管理提供重要智力资源。%To gather crisis early-warning information is very difficult because of the complexity of crisis information. The construction of enterprise social network relationship model will contribute to the accuracy and effectiveness in crisis information management. The paper analyzes the relationship between crisis early warning information gathering and social network theory(i, e. , tie strength theory, the structural hole theory). It describes enterprise internal social network model based on structural holes theory and enterprise external social network model based on tie strength theory. At the end, the paper thinks that it can gather crisis information from social network, and social network provides some important intellectual resources for enterprise crisis information management.

  20. Early warning, warning or alarm systems for natural hazards? A generic classification.

    Science.gov (United States)

    Sättele, Martina; Bründl, Michael; Straub, Daniel

    2013-04-01

    Early warning, warning and alarm systems have gained popularity in recent years as cost-efficient measures for dangerous natural hazard processes such as floods, storms, rock and snow avalanches, debris flows, rock and ice falls, landslides, flash floods, glacier lake outburst floods, forest fires and even earthquakes. These systems can generate information before an event causes loss of property and life. In this way, they mainly mitigate the overall risk by reducing the presence probability of endangered objects. These systems are typically prototypes tailored to specific project needs. Despite their importance there is no recognised system classification. This contribution classifies warning and alarm systems into three classes: i) threshold systems, ii) expert systems and iii) model-based expert systems. The result is a generic classification, which takes the characteristics of the natural hazard process itself and the related monitoring possibilities into account. The choice of the monitoring parameters directly determines the system's lead time. The classification of 52 active systems moreover revealed typical system characteristics for each system class. i) Threshold systems monitor dynamic process parameters of ongoing events (e.g. water level of a debris flow) and incorporate minor lead times. They have a local geographical coverage and a predefined threshold determines if an alarm is automatically activated to warn endangered objects, authorities and system operators. ii) Expert systems monitor direct changes in the variable disposition (e.g crack opening before a rock avalanche) or trigger events (e.g. heavy rain) at a local scale before the main event starts and thus offer extended lead times. The final alarm decision incorporates human, model and organisational related factors. iii) Model-based expert systems monitor indirect changes in the variable disposition (e.g. snow temperature, height or solar radiation that influence the occurrence probability

  1. Empirical study on early warning of stock index futures manipulation based on logistic model%股指期货操纵预警的Logistic模型实证研究

    Institute of Scientific and Technical Information of China (English)

    熊熊; 张宇; 张维; 张永杰

    2011-01-01

    Most studies on early warning of the security market manipulation only focus on stock market or futures market. With the rapid development of Stock Index Futures, the early warning of Stock Index Futures manipulation becomes very important. This paper, based on Logistic Regression Model, uses the volatility and liquidity indicators to estimate the probability of Stock Index Futures Market manipulation and sets up a early warning model on Stock Index Futures Market manipulation. Further, the inter-day transaction data of Hang Seng Index Futures both during the period of manipulation and the period of non-manipulation are used to test our model. The empirical results show that this model can give good early warning on Stock Index Futures Market manipulation events. We also find that the trading volume and Open-int are significantly different between the manipulation period and non-manipulation period, but the changes of volatility and yield ratio aren't so significant. So we can use the trading volume and Open-int to distinguish the manipulation events. According to our empirical study, we find, during manipulation periods, there are significant changes in the probability of Stock Index Futures Market manipulation. Our' Logistic model can identify the manipulation in Stock Index Futures market effectively.%通过建立Logistic回归模型判别股指期货被操纵的可能性,将股指期货是否被操纵的问题转化为根据一定时期内股指期货市场的波动性以及流动性指标计算股指期货在一定时间内被操纵的概率,建立了股指期货操纵事件的预警模型.选取香港恒生指数期货操纵时段和对应的非操纵时段,进行了预警模型的实证检验,证明了该模型可以对股指期货操纵事件起到较好的预警作用.研究发现,在股指期货市场中,操纵期与非操纵期的交易量和空盘量显著不同,而反映市场波动性的收益率指标的变化并不显著,对操纵行为是否发生

  2. Storm Warnings on Lake Balaton,

    Science.gov (United States)

    1982-04-06

    magnitude of this effect. Consequently, the employees of the Storm Warning Service decided in the course of the summer 1962, to set up a cup -type... anemometer on a passenger ship regularly passing between Si6fok and Balatonfired, and to take wind measurements along this route across the Lake in a...along this route. During the measurements, the reading of the anemometer was taken at intervals and noted together with the time of reading. Since the

  3. VisionSense - An advanced lateral collision warning system

    OpenAIRE

    Dijck, T.; Heijden, van der, M.C.

    2005-01-01

    VisionSense is an advanced driver assistance system which combines a lateral collision warning system with vehicle-to-vehicle communication. This paper shows the results of user needs assessment and traffic safety modelling of VisionSense. User needs were determined by means of a Web-based survey. The results show, that VisionSense is most appreciated when it uses a light signal to warn the driver in a possibly hazardous situation on a highway. The willingness to pay is estimated at 300 Euros...

  4. Numerical modeling of the initial fluctuation condensation stage with charge drops

    Science.gov (United States)

    Averina, T. A.; Zmievskaya, G. I.

    2016-11-01

    This paper deals with a mathematical model of the phase transition of the first kind at the initial stage of forming drops in a liquid or in melted state in a volume of steam with a fixed charge on drops. The model of the process is represented by superposition of random diffusion and jump stochastic processes. The algorithms for solving stochastic differential equations (SDEs) of the model of processes, which form the cluster size, allow one to calculate a distribution function of drops according to their size. The kinetic approach makes possible evaluate the role of the Rayleigh capillary instability at the initial condensation stage and to employ the analysis of electrodispersion mechanisms in the production of metal and semiconductor powders.

  5. Modeling TGF-β in early stages of cancer tissue dynamics.

    Directory of Open Access Journals (Sweden)

    Gianluca Ascolani

    Full Text Available Recent works have highlighted a double role for the Transforming Growth Factor β (TGF-β: it inhibits cancer in healthy cells and potentiates tumor progression during late stage of tumorigenicity, respectively; therefore it has been termed the "Jekyll and Hyde" of cancer or, alternatively, an "excellent servant but a bad master". It remains unclear how this molecule could have the two opposite behaviours. In this work, we propose a TGF-β multi scale mathematical model at molecular, cellular and tissue scales. The multi scalar behaviours of the TGF-β are described by three coupled models built up together which can approximatively be related to distinct microscopic, mesoscopic, and macroscopic scales, respectively. We first model the dynamics of TGF-β at the single-cell level by taking into account the intracellular and extracellular balance and the autocrine and paracrine behaviour of TGF-β. Then we use the average estimates of the TGF-β from the first model to understand its dynamics in a model of duct breast tissue. Although the cellular model and the tissue model describe phenomena at different time scales, their cumulative dynamics explain the changes in the role of TGF-β in the progression from healthy to pre-tumoral to cancer. We estimate various parameters by using available gene expression datasets. Despite the fact that our model does not describe an explicit tissue geometry, it provides quantitative inference on the stage and progression of breast cancer tissue invasion that could be compared with epidemiological data in literature. Finally in the last model, we investigated the invasion of breast cancer cells in the bone niches and the subsequent disregulation of bone remodeling processes. The bone model provides an effective description of the bone dynamics in healthy and early stages cancer conditions and offers an evolutionary ecological perspective of the dynamics of the competition between cancer and healthy cells.

  6. NOAA-USGS Debris-Flow Warning System - Final Report

    Science.gov (United States)

    ,

    2005-01-01

    Landslides and debris flows cause loss of life and millions of dollars in property damage annually in the United States (National Research Council, 2004). In an effort to reduce loss of life by debris flows, the National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) and the U.S. Geological Survey (USGS) operated an experimental debris-flow prediction and warning system in the San Francisco Bay area from 1986 to 1995 that relied on forecasts and measurements of precipitation linked to empirical precipitation thresholds to predict the onset of rainfall-triggered debris flows. Since 1995, there have been substantial improvements in quantifying precipitation estimates and forecasts, development of better models for delineating landslide hazards, and advancements in geographic information technology that allow stronger spatial and temporal linkage between precipitation forecasts and hazard models. Unfortunately, there have also been several debris flows that have caused loss of life and property across the United States. Establishment of debris-flow warning systems in areas where linkages between rainfall amounts and debris-flow occurrence have been identified can help mitigate the hazards posed by these types of landslides. Development of a national warning system can help support the NOAA-USGS goal of issuing timely Warnings of potential debris flows to the affected populace and civil authorities on a broader scale. This document presents the findings and recommendations of a joint NOAA-USGS Task Force that assessed the current state-of-the-art in precipitation forecasting and debris-flow hazard-assessment techniques. This report includes an assessment of the science and resources needed to establish a demonstration debris-flow warning project in recently burned areas of southern California and the necessary scientific advancements and resources associated with expanding such a warning system to unburned areas and, possibly, to a

  7. Integrating life stages into ecological niche models: a case study on tiger beetles.

    Directory of Open Access Journals (Sweden)

    Angela Taboada

    Full Text Available Detailed understanding of a species' natural history and environmental needs across spatial scales is a primary requisite for effective conservation planning, particularly for species with complex life cycles in which different life stages occupy different niches and respond to the environment at different scales. However, niche models applied to conservation often neglect early life stages and are mostly performed at broad spatial scales. Using the endangered heath tiger beetle (Cicindela sylvatica as a model species, we relate presence/absence and abundance data of locally dispersing adults and sedentary larvae to abiotic and biotic variables measured in a multiscale approach within the geographic extent relevant to active conservation management. At the scale of hundreds of meters, fine-grained abiotic conditions (i.e., vegetation structure are fundamental determinants of the occurrence of both life stages, whereas the effect of biotic factors is mostly contained in the abiotic signature. The combination of dense heath vegetation and bare ground areas is thus the first requirement for the species' preservation, provided that accessibility to the suitable habitat is ensured. At a smaller scale (centimetres, the influence of abiotic factors on larval occurrence becomes negligible, suggesting the existence of important additional variables acting within larval proximity. Sustained significant correlations between neighbouring larvae in the models provide an indication of the potential impact of neighbourhood crowding on the larval niche within a few centimetres. Since the species spends the majority of its life cycle in the larval stage, it is essential to consider the hierarchical abiotic and biotic processes affecting the larvae when designing practical conservation guidelines for the species. This underlines the necessity for a more critical evaluation of the consequences of disregarding niche variation between life stages when estimating

  8. A multi-stage 3-D stress field modelling approach exemplified in the Bavarian Molasse Basin

    Science.gov (United States)

    Ziegler, Moritz O.; Heidbach, Oliver; Reinecker, John; Przybycin, Anna M.; Scheck-Wenderoth, Magdalena

    2016-09-01

    The knowledge of the contemporary in situ stress state is a key issue for safe and sustainable subsurface engineering. However, information on the orientation and magnitudes of the stress state is limited and often not available for the areas of interest. Therefore 3-D geomechanical-numerical modelling is used to estimate the in situ stress state and the distance of faults from failure for application in subsurface engineering. The main challenge in this approach is to bridge the gap in scale between the widely scattered data used for calibration of the model and the high resolution in the target area required for the application. We present a multi-stage 3-D geomechanical-numerical approach which provides a state-of-the-art model of the stress field for a reservoir-scale area from widely scattered data records. Therefore, we first use a large-scale regional model which is calibrated by available stress data and provides the full 3-D stress tensor at discrete points in the entire model volume. The modelled stress state is used subsequently for the calibration of a smaller-scale model located within the large-scale model in an area without any observed stress data records. We exemplify this approach with two-stages for the area around Munich in the German Molasse Basin. As an example of application, we estimate the scalar values for slip tendency and fracture potential from the model results as measures for the criticality of fault reactivation in the reservoir-scale model. The modelling results show that variations due to uncertainties in the input data are mainly introduced by the uncertain material properties and missing SHmax magnitude estimates needed for a more reliable model calibration. This leads to the conclusion that at this stage the model's reliability depends only on the amount and quality of available stress information rather than on the modelling technique itself or on local details of the model geometry. Any improvements in modelling and increases

  9. Global stability of a delayed mosquito-transmitted disease model with stage structure

    Directory of Open Access Journals (Sweden)

    B. G. Sampath Aruna Pradeep

    2015-01-01

    Full Text Available This article presents a new eco-epidemiological deterministic delay differential equation model considering a biological controlling approach on mosquitoes, for endemic dengue disease with variable host (human and variable vector (Aedes aegypti populations, and stage structure for mosquitoes. In this model, predator-prey interaction is considered by using larvae as prey and mosquito-fish as predator. We give a complete classification of equilibria of the model, and sufficient conditions for global stability/global attractivity of some equilibria are given by constructing suitable Lyapunov functionals and using Lyapunov-LaSalle invariance principle. Also, numerical simulations are presented to show the validity of our results.

  10. Early warning of critical transitions in biodiversity from compositional disorder

    DEFF Research Database (Denmark)

    Doncaster, C. Patrick; Alonso Chávez, Vasthi; Viguier, Clément;

    2016-01-01

    of species in the community. In a stochastic simulation, sequential correlations over time switch from positive to negative as keystones prevail over canaries, and back to positive with domination of weedy species. The model finds support in empirical tests on multi-decadal time series of fossil diatom...... the identification of early-warning signals from other metrics....

  11. Monte Carlo Error Analysis Applied to Core Formation: The Single-stage Model Revived

    Science.gov (United States)

    Cottrell, E.; Walter, M. J.

    2009-12-01

    The last decade has witnessed an explosion of studies that scrutinize whether or not the siderophile element budget of the modern mantle can plausibly be explained by metal-silicate equilibration in a deep magma ocean during core formation. The single-stage equilibrium scenario is seductive because experiments that equilibrate metal and silicate can then serve as a proxy for the early earth, and the physical and chemical conditions of core formation can be identified. Recently, models have become more complex as they try to accommodate the proliferation of element partitioning data sets, each of which sets its own limits on the pressure, temperature, and chemistry of equilibration. The ability of single stage models to explain mantle chemistry has subsequently been challenged, resulting in the development of complex multi-stage core formation models. Here we show that the extent to which extant partitioning data are consistent with single-stage core formation depends heavily upon (1) the assumptions made when regressing experimental partitioning data (2) the certainty with which regression coefficients are known and (3) the certainty with which the core/mantle concentration ratios of the siderophile elements are known. We introduce a Monte Carlo algorithm coded in MATLAB that samples parameter space in pressure and oxygen fugacity for a given mantle composition (nbo/t) and liquidus, and returns the number of equilibrium single-stage liquidus “solutions” that are permissible, taking into account the uncertainty in regression parameters and range of acceptable core/mantle ratios. Here we explore the consequences of regression parameter uncertainty and the impact of regression construction on model outcomes. We find that the form of the partition coefficient (Kd with enforced valence state, or D) and the handling of the temperature effect (based on 1-atm free energy data or high P-T experimental observations) critically affects model outcomes. We consider the most

  12. Dynamics of an HIV Model with Multiple Infection Stages and Treatment with Different Drug Classes.

    Science.gov (United States)

    Wang, Xia; Song, Xinyu; Tang, Sanyi; Rong, Libin

    2016-02-01

    Highly active antiretroviral therapy can effectively control HIV replication in infected individuals. Some clinical and modeling studies suggested that viral decay dynamics may depend on the inhibited stages of the viral replication cycle. In this paper, we develop a general mathematical model incorporating multiple infection stages and various drug classes that can interfere with specific stages of the viral life cycle. We derive the basic reproductive number and obtain the global stability results of steady states. Using several simple cases of the general model, we study the effect of various drug classes on the dynamics of HIV decay. When drugs are assumed to be 100% effective, drugs acting later in the viral life cycle lead to a faster or more rapid decay in viremia. This is consistent with some patient and experimental data, and also agrees with previous modeling results. When drugs are not 100% effective, the viral decay dynamics are more complicated. Without a second population of long-lived infected cells, the viral load decline can have two phases if drugs act at an intermediate stage of the viral replication cycle. The slopes of viral load decline depend on the drug effectiveness, the death rate of infected cells at different stages, and the transition rate of infected cells from one to the next stage. With a second population of long-lived infected cells, the viral load decline can have three distinct phases, consistent with the observation in patients receiving antiretroviral therapy containing the integrase inhibitor raltegravir. We also fit modeling prediction to patient data under efavirenz (a nonnucleoside reverse-transcriptase inhibitor) and raltegravir treatment. The first-phase viral load decline under raltegravir therapy is longer than that under efavirenz, resulting in a lower viral load at initiation of the second-phase decline in patients taking raltegravir. This explains why patients taking a raltegravir-based therapy were faster to achieve

  13. Warning against the dangers of wildfires in the Czech Republic

    Science.gov (United States)

    Mozny, M.; Bares, D.; Virag, M.; Stalmacher, J.

    2009-04-01

    Many fire risk models have been developed for various temporal and spatial scales and application purposes. The integrated warning service in the Czech Republic is used for wildfire risk assessment model of FDI (Fire Danger Index). The FDI model is being developed in the Doksany observatory based on evaluation of weather conditions. FDI model describes danger of wildfire for vegetation covered countryside. There are five levels of danger: 1 - very low risk, 2 - low risk, 3 - moderate risk, 4 - high risk, 5 - very high risk. Simply say higher index value, reflects to higher risk of wildfire. As input data, the model uses measured values from the Czech Hydrometeorological Institute stations network as well as ALADIN's model predicted conditions. The modelling process computes upper soil profile moisture, surface moistening and the spreading speed of fire. Early warning system for wildfires prevention in the Czech Republic is used since 2006.

  14. Reliability in the Power System Modeled in a Multi- Stage Stochastic Mixed Integer Programming Model

    DEFF Research Database (Denmark)

    Simonsen Nielsen, Michael Pascal

    Contributions from this article are that it takes the characteristics of the power system into account at different stages, which gives a more realistic presentation of the welfare aspects to be gained by an optimal operation/ dispatch of the power system. This article is utilizing a Multi...

  15. Colorimetric characterization of liquid crystal display using an improved two-stage model

    Institute of Scientific and Technical Information of China (English)

    Yong Wang; Haisong Xu

    2006-01-01

    @@ An improved two-stage model of colorimetric characterization for liquid crystal display (LCD) was proposed. The model included an S-shape nonlinear function with four coefficients for each channel to fit the Tone reproduction curve (TRC), and a linear transfer matrix with black-level correction. To compare with the simple model (SM), gain-offset-gain (GOG), S-curve and three-one-dimensional look-up tables (3-1D LUTs) models, an identical LCD was characterized and the color differences were calculated and summarized using the set of 7 × 7 × 7 digital-to-analog converter (DAC) triplets as test data. The experimental results showed that the model was outperformed in comparison with the GOG and SM ones, and near to that of the S-curve model and 3-1D LUTs method.

  16. Trading stages

    DEFF Research Database (Denmark)

    Steiner, Uli; Tuljapurkar, Shripad; Coulson, Tim

    2012-01-01

    Interest in stage-and age structured models has recently increased because they can describe quantitative traits such as size that are left out of age-only demography. Available methods for the analysis of effects of vital rates on lifespan in stage-structured models have not been widely applied ...... examples. Much of our approach relies on trading of time and mortality risk in one stage for time and risk in others. Our approach contributes to the new framework of the study of age- and stage-structured biodemography....

  17. Flow ensemble prediction for flash flood warnings at ungauged basins

    Science.gov (United States)

    Demargne, Julie; Javelle, Pierre; Organde, Didier; Caseri, Angelica; Ramos, Maria-Helena; de Saint Aubin, Céline; Jurdy, Nicolas

    2015-04-01

    Flash floods, which are typically triggered by severe rainfall events, are difficult to monitor and predict at the spatial and temporal scales of interest due to large meteorological and hydrologic uncertainties. In particular, uncertainties in quantitative precipitation forecasts (QPF) and quantitative precipitation estimates (QPE) need to be taken into account to provide skillful flash flood warnings with increased warning lead time. In France, the AIGA discharge-threshold flood warning system is currently being enhanced to ingest high-resolution ensemble QPFs from convection-permitting numerical weather prediction (NWP) models, as well as probabilistic QPEs, to improve flash flood warnings for small-to-medium (from 10 to 1000 km²) ungauged basins. The current deterministic AIGA system is operational in the South of France since 2005. It ingests the operational radar-gauge QPE grids from Météo-France to run a simplified hourly distributed hydrologic model at a 1-km² resolution every 15 minutes (Javelle et al. 2014). This produces real-time peak discharge estimates along the river network, which are subsequently compared to regionalized flood frequency estimates of given return periods. Warnings are then provided to the French national hydro-meteorological and flood forecasting centre (SCHAPI) and regional flood forecasting offices, based on the estimated severity of ongoing events. The calibration and regionalization of the hydrologic model has been recently enhanced to implement an operational flash flood warning system for the entire French territory. To quantify the QPF uncertainty, the COSMO-DE-EPS rainfall ensembles from the Deutscher Wetterdienst (20 members at a 2.8-km resolution for a lead time of 21 hours), which are available on the North-eastern part of France, were ingested in the hydrologic model of the AIGA system. Streamflow ensembles were produced and probabilistic flash flood warnings were derived for the Meuse and Moselle river basins and

  18. Tornado Warning Perception and Response: Integrating the Roles of Visual Design, Demographics, and Hazard Experience.

    Science.gov (United States)

    Schumann, Ronald L; Ash, Kevin D; Bowser, Gregg C

    2017-06-30

    Recent advancements in severe weather detection and warning dissemination technologies have reduced, but not eliminated, large-casualty tornado hazards in the United States. Research on warning cognition and behavioral response by the public has the potential to further reduce tornado-related deaths and injuries; however, less research has been conducted in this area compared to tornado research in the physical sciences. Extant research in this vein tends to bifurcate. One branch of studies derives from classic risk perception, which investigates cognitive, affective, and sociocultural factors in relation to concern and preparation for uncertain risks. Another branch focuses on psychological, social, and cultural factors implicated in warning response for rapid onset hazards, with attention paid to previous experience and message design. Few studies link risk perceptions with cognition and response as elicited by specific examples of warnings. The present study unites risk perception, cognition, and response approaches by testing the contributions of hypothesized warning response drivers in one set of path models. Warning response is approximated by perceived fear and intended protective action as reported by survey respondents when exposed to hypothetical tornado warning scenarios. This study considers the roles of hazard knowledge acquisition, information-seeking behaviors, previous experience, and sociodemographic factors while controlling for the effects of the visual warning graphic. Findings from the study indicate the primacy of a user's visual interpretation of a warning graphic in shaping tornado warning response. Results also suggest that information-seeking habits, previous tornado experience, and local disaster culture play strong influencing roles in warning response. © 2017 Society for Risk Analysis.

  19. A model of pyrolysis in a staged scheme of low-grade solid fuel gasification

    Science.gov (United States)

    Levin, A. A.; Shamansky, V. A.; Kozlov, A. N.

    2016-10-01

    The development and evolution of the theory of solid fuel combustion took place in the mid-20th century. The most studied research subject was sized fossil coal. At the same time the research on the fuels with a high yield of volatile matter (biomass) was limited due to insufficient data on kinetics of physical and chemical processes that occur at their heating. Obviously, the creation of a prospective low-tonnage technology for staged gasification of wooden biomass is possible only when a detailed mechanism of these processes is well understood and their kinetic parameters are known. This paper presents the initial results of the development of a model of wood pyrolysis in a screw reactor as the first stage of the multistage gasification process. One of the currently set goals in this research is to develop a mathematical model of heat and mass transfer processes to perform optimization calculations.

  20. Coupled simulation of CFD-flight-mechanics with a two-species-gas-model for the hot rocket staging

    Science.gov (United States)

    Li, Yi; Reimann, Bodo; Eggers, Thino

    2016-11-01

    The hot rocket staging is to separate the lowest stage by directly ignite the continuing-stage-motor. During the hot staging, the rocket stages move in a harsh dynamic environment. In this work, the hot staging dynamics of a multistage rocket is studied using the coupled simulation of Computational Fluid Dynamics and Flight Mechanics. Plume modeling is crucial for a coupled simulation with high fidelity. A 2-species-gas model is proposed to simulate the flow system of the rocket during the staging: the free-stream is modeled as "cold air" and the exhausted plume from the continuing-stage-motor is modeled with an equivalent calorically-perfect-gas that approximates the properties of the plume at the nozzle exit. This gas model can well comprise between the computation accuracy and efficiency. In the coupled simulations, the Navier-Stokes equations are time-accurately solved in moving system, with which the Flight Mechanics equations can be fully coupled. The Chimera mesh technique is utilized to deal with the relative motions of the separated stages. A few representative staging cases with different initial flight conditions of the rocket are studied with the coupled simulation. The torque led by the plume-induced-flow-separation at the aft-wall of the continuing-stage is captured during the staging, which can assist the design of the controller of the rocket. With the increasing of the initial angle-of-attack of the rocket, the staging quality becomes evidently poorer, but the separated stages are generally stable when the initial angle-of-attack of the rocket is small.

  1. Spallation Fragment Investigation on Nb, Au and Pb by Using Many Stage Dynamical Model

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The formation cross section of the nuclides production of proton-induced nuclear reactions withintermediate energy is of importance for a variety of applications. For instance, the mass and chargedistribution of residual products produced in the spallation reactions needs to be studied, because it canprovide useful information for the disposal of nuclear waste and residual radioactivity generated by thespallation neutron target system. At present work, we developed the many stage dynamical model

  2. Lumped-equivalent circuit model for multi-stage cascaded magnetoelectric dual-tunable bandpass filter

    Institute of Scientific and Technical Information of China (English)

    张秋实; 朱锋杰; 周浩淼

    2015-01-01

    A lumped-equivalent circuit model of a novel magnetoelectric tunable bandpass filter, which is realized in the form of multi-stage cascading between a plurality of magnetoelectric laminates, is established in this paper for convenient analysis. The multi-stage cascaded filter is degraded to the coupling microstrip filter with only one magnetoelectric laminate and then compared with the existing experiment results. The comparison reveals that the insertion loss curves predicted by the degraded circuit model are in good agreement with the experiment results and the predicted results of the electromagnetic field simulation, thus the validity of the model is verified. The model is then degraded to the two-stage cascaded magneto-electric filter with two magnetoelectric laminates. It is revealed that if the applied external bias magnetic or electric fields on the two magnetoelectric laminates are identical, then the passband of the filter will drift under the changed external field; that is to say, the filter has the characteristics of external magnetic field tunability and electric field tunability. If the applied external bias magnetic or electric fields on two magnetoelectric laminates are different, then the passband will disappear so that the switching characteristic is achieved. When the same magnetic fields are applied to the laminates, the passband bandwidth of the two-stage cascaded magnetoelectric filter with two magnetoelectric laminates becomes nearly doubled in comparison with the passband filter which contains only one magnetoelectric laminate. The bandpass effect is also improved obviously. This research will provide a theoretical basis for the design, preparation, and application of a new high performance magnetoelectric tunable microwave device.

  3. Life stage and resistance effects in modelling phosphine fumigation of Rhyzopertha dominica (F.)

    OpenAIRE

    Thorne, J.; Fulford, G.; Ridley, A.; Schlipalius, D.; P. Collins

    2010-01-01

    Resistance to phosphine in insect pests of stored grain is a serious problem and there is a world-wide need for the development of sustainable resistance management strategies. Here we introduce results from a new mathematical model of resistance development that includes all life stages, rates of oviposition, natural mortality and mortality under fumigation in relation to resistant genotype. The example we discuss is phosphine resistance in the lesser grain borer, Rhyzopertha dominica where ...

  4. Photon spectra from final stages of a primordial black hole evaporation in different theoretical models

    CERN Document Server

    Bugaev, Edgar; Petkov, Valery

    2007-01-01

    Possibilities of an experimental search for gamma-ray bursts from primordial black hole (PBH) evaporations in space are reconsidered. It is argued that the corresponding constraints which can be obtained in experiments with cosmic ray detectors strongly depend on theoretical approach used for a description of the PBH evaporation process. Predictions of several theoretical models for gamma-ray spectra from final stages of PBH life (integrated over time) are given.

  5. Cancerous Tumour Model Analysis and Constructing schemes of Anti-angiogenesis Therapy at an Early Stage

    Directory of Open Access Journals (Sweden)

    O. Yu. Mukhomorova

    2015-01-01

    Full Text Available Anti-angiogenesis therapy is an alternative and successfully employed method for treatment of cancerous tumour. However, this therapy isn't widely used in medicine because of expensive drugs. It leads naturally to elaboration of such treatment regimens which use minimum amount of drugs.The aim of the paper is to investigate the model of development of illness and elaborate appropriate treatment regimens in the case of early diagnosis of the disease. The given model reflects the therapy at an intermediate stage of the disease treatment. Further treatment is aimed to destroy cancer cells and may be continued by other means, which are not reflected in the model.Analysis of the main properties of the model was carried out with consideration of two types of auxiliary systems. In the first case, the system is considered without control, as a model of tumour development in the absence of medical treatment. The study of the equilibrium point and determination of its type allowed us to describe disease dynamics and to determine tumour size resulting in death. In the second case a model with a constant control was investigated. The study of its equilibrium point showed that continuous control is not sufficient to support satisfactory patient's condition, and it is necessary to elaborate more complex treatment regimens. For this purpose, we used the method of terminal problems consisting in the search for such program control which forces system to a given final state. Selecting the initial and final states is due to medical grounds.As a result, we found two treatment regimens | one-stage treatment regimen and multi-stage one. The properties of each treatment regimen are analyzed and compared. The total amount of used drugs was a criterion for comparing these two treatment regimens. The theoretical conclusions obtained in this work are supported by computer modeling in MATLAB environment.

  6. A Human Life-Stage Physiologically Based Pharmacokinetic and Pharmacodynamic Model for Chlorpyrifos: Development and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jordan N.; Hinderliter, Paul M.; Timchalk, Charles; Bartels, M. J.; Poet, Torka S.

    2014-08-01

    Sensitivity to chemicals in animals and humans are known to vary with age. Age-related changes in sensitivity to chlorpyrifos have been reported in animal models. A life-stage physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model was developed to computationally predict disposition of CPF and its metabolites, chlorpyrifos-oxon (the ultimate toxicant) and 3,5,6-trichloro-2-pyridinol (TCPy), as well as B-esterase inhibition by chlorpyrifos-oxon in humans. In this model, age-dependent body weight was calculated from a generalized Gompertz function, and compartments (liver, brain, fat, blood, diaphragm, rapid, and slow) were scaled based on body weight from polynomial functions on a fractional body weight basis. Blood flows among compartments were calculated as a constant flow per compartment volume. The life-stage PBPK/PD model was calibrated and tested against controlled adult human exposure studies. Model simulations suggest age-dependent pharmacokinetics and response may exist. At oral doses ≥ 0.55 mg/kg of chlorpyrifos (significantly higher than environmental exposure levels), 6 mo old children are predicted to have higher levels of chlorpyrifos-oxon in blood and higher levels of red blood cell cholinesterase inhibition compared to adults from equivalent oral doses of chlorpyrifos. At lower doses that are more relevant to environmental exposures, the model predicts that adults will have slightly higher levels of chlorpyrifos-oxon in blood and greater cholinesterase inhibition. This model provides a computational framework for age-comparative simulations that can be utilized to predict CPF disposition and biological response over various postnatal life-stages.

  7. Waterhammer Modeling for the Ares I Upper Stage Reaction Control System Cold Flow Development Test Article

    Science.gov (United States)

    Williams, Jonathan H.

    2010-01-01

    The Upper Stage Reaction Control System provides three-axis attitude control for the Ares I launch vehicle during active Upper Stage flight. The system design must accommodate rapid thruster firing to maintain the proper launch trajectory and thus allow for the possibility to pulse multiple thrusters simultaneously. Rapid thruster valve closure creates an increase in static pressure, known as waterhammer, which propagates throughout the propellant system at pressures exceeding nominal design values. A series of development tests conducted in the fall of 2009 at Marshall Space Flight Center were performed using a water-flow test article to better understand fluid performance characteristics of the Upper Stage Reaction Control System. A subset of the tests examined waterhammer along with the subsequent pressure and frequency response in the flight-representative system and provided data to anchor numerical models. This thesis presents a comparison of waterhammer test results with numerical model and analytical results. An overview of the flight system, test article, modeling and analysis are also provided.

  8. Two-stage model in perceptual learning: toward a unified theory.

    Science.gov (United States)

    Shibata, Kazuhisa; Sagi, Dov; Watanabe, Takeo

    2014-05-01

    Training or exposure to a visual feature leads to a long-term improvement in performance on visual tasks that employ this feature. Such performance improvements and the processes that govern them are called visual perceptual learning (VPL). As an ever greater volume of research accumulates in the field, we have reached a point where a unifying model of VPL should be sought. A new wave of research findings has exposed diverging results along three major directions in VPL: specificity versus generalization of VPL, lower versus higher brain locus of VPL, and task-relevant versus task-irrelevant VPL. In this review, we propose a new theoretical model that suggests the involvement of two different stages in VPL: a low-level, stimulus-driven stage, and a higher-level stage dominated by task demands. If experimentally verified, this model would not only constructively unify the current divergent results in the VPL field, but would also lead to a significantly better understanding of visual plasticity, which may, in turn, lead to interventions to ameliorate diseases affecting vision and other pathological or age-related visual and nonvisual declines.

  9. Fetal Origins of Life Stage Disease: A Zebrafish Model for the ...

    Science.gov (United States)

    In the U.S., childhood obesity has more than doubled in children and quadrupled in adolescents in the past 30 years, affects 35% of adults, and costs the U.S. healthcare industry >$200 billion annually. The chemical environment in the womb may cause susceptibility to different life-stage and life-long metabolic diseases including obesity. The challenge is to understand if exposures during developmentally sensitive windows impact life-stage disease, such as obesity, by increasing adipose tissue mass. In vitro models lack the integrated systems approach needed to assess adipose development, while mammalian models are impractical in a screen of thousands of chemicals. Therefore, an obesogen screening method was developed to interrogate bioactivity using a full systems approach, in a vertebrate zebrafish model with complete metabolic activity, at a time when the full signaling repertoire is expressed and active, to optimally examine how chemical dose and duration impact life-stage adipose mass. A time-line for adipose depot formation was mapped in zebrafish 6−14 days post fertilization (dpf) using the lipophilic dye, Nile Red, in combination with fluorescent microscopy. Those time points were then used to investigate the impact of embryonic tributyltin chloride (TBT, a known obesogen) exposure (10nM daily renewal, 0−5dpf) on adipose mass. Fluorescent microscopy revealed adipose depots that were larger and appeared 2 days earlier in TBT treated compared to contro

  10. Adaptive Urban Stormwater Management Using a Two-stage Stochastic Optimization Model

    Science.gov (United States)

    Hung, F.; Hobbs, B. F.; McGarity, A. E.

    2014-12-01

    In many older cities, stormwater results in combined sewer overflows (CSOs) and consequent water quality impairments. Because of the expense of traditional approaches for controlling CSOs, cities are considering the use of green infrastructure (GI) to reduce runoff and pollutants. Examples of GI include tree trenches, rain gardens, green roofs, and rain barrels. However, the cost and effectiveness of GI are uncertain, especially at the watershed scale. We present a two-stage stochastic extension of the Stormwater Investment Strategy Evaluation (StormWISE) model (A. McGarity, JWRPM, 2012, 111-24) to explicitly model and optimize these uncertainties in an adaptive management framework. A two-stage model represents the immediate commitment of resources ("here & now") followed by later investment and adaptation decisions ("wait & see"). A case study is presented for Philadelphia, which intends to extensively deploy GI over the next two decades (PWD, "Green City, Clean Water - Implementation and Adaptive Management Plan," 2011). After first-stage decisions are made, the model updates the stochastic objective and constraints (learning). We model two types of "learning" about GI cost and performance. One assumes that learning occurs over time, is automatic, and does not depend on what has been done in stage one (basic model). The other considers learning resulting from active experimentation and learning-by-doing (advanced model). Both require expert probability elicitations, and learning from research and monitoring is modelled by Bayesian updating (as in S. Jacobi et al., JWRPM, 2013, 534-43). The model allocates limited financial resources to GI investments over time to achieve multiple objectives with a given reliability. Objectives include minimizing construction and O&M costs; achieving nutrient, sediment, and runoff volume targets; and community concerns, such as aesthetics, CO2 emissions, heat islands, and recreational values. CVaR (Conditional Value at Risk) and

  11. Automatic detection and classification of sleep stages by multichannel EEG signal modeling.

    Science.gov (United States)

    Zhovna, Inna; Shallom, Ilan D

    2008-01-01

    In this paper a novel method for automatic detection and classification of sleep stages using a multichannel electroencephalography (EEG) is presented. Understanding the sleep mechanism is vital for diagnosis and treatment of sleep disorders. The EEG is one of the most important tools of studying and diagnosing sleep disorders. EEG signals waveforms activity interpretation is performed by visual analysis (a very difficult procedure). This research aim is to ease the difficulties involved in the existing manual process of EEG interpretation by proposing an automatic sleep stage detection and classification system. The suggested method based on Multichannel Auto Regressive (MAR) model. The multichannel analysis approach incorporates the cross correlation information existing between different EEG signals. In the training phase, we used the vector quantization (VQ) algorithm, Linde-Buzo-Gray (LBG) and sleep stage definition, by estimation of probability mass functions (pmf) per every sleep stage using Generalized Log Likelihood Ratio (GLLR) distortion. The classification phase was performed using Kullback-Leibler (KL) divergence. The results of this research are promising with classification accuracy rate of 93.2%. The results encourage continuation of this research in the sleep field and in other biomedical signals applications.

  12. STOCHASTIC DISCRETE MODEL OF TWO-STAGE ISOLATION SYSTEM WITH RIGID LIMITERS

    Institute of Scientific and Technical Information of China (English)

    HE Hua; FENG Qi; SHEN Rong-ying; WANG Yu

    2006-01-01

    The possible intermittent impacts of a two-stage isolation system with rigid limiters have been investigated. The isolation system is under periodic external excitation disturbed by small stationary Gaussian white noise after shock. The maximal impact Then in the period after shock, the zero order approximate stochastic discrete model and the first order approximate stochastic model are developed. The real isolation system of an MTU diesel engine is used to evaluate the established model. After calculating of the numerical example, the effects of noise excitation on the isolation system are discussed.The results show that the property of the system is complicated due to intermittent impact. The difference between zero order model and the first order model may be great.The effect of small noise is obvious. The results may be expected useful to the naval designers.

  13. New numerical model for thermal quenching mechanism in quartz based on two-stage thermal stimulation of thermoluminescence model

    Directory of Open Access Journals (Sweden)

    Ahmed Kadari

    2015-11-01

    Full Text Available The effect of thermal quenching plays an important role in the thermoluminescence (TL of quartz on which many applications of TL are based. The studies of the stability and kinetics of the 325 °C thermoluminescence peak in quartz are described by Wintle (1975, which show the occurrence of thermal quenching, the decrease in luminescence efficiency with rise in temperature. The thermal quenching of thermoluminescence in quartz was studied experimentally by several authors. The simulations work presented in the literature is based on the single-stage thermal stimulation model of thermoluminescence, in spite of that the mechanisms of this effect remain incomplete. This paper presents a new numerical model for thermal quenching in quartz, using the previously published two-stage thermal stimulation of thermoluminescence model.

  14. Dynamics of a Stage Structured Pest Control Model in a Polluted Environment with Pulse Pollution Input

    Directory of Open Access Journals (Sweden)

    Bing Liu

    2013-01-01

    Full Text Available By using pollution model and impulsive delay differential equation, we formulate a pest control model with stage structure for natural enemy in a polluted environment by introducing a constant periodic pollutant input and killing pest at different fixed moments and investigate the dynamics of such a system. We assume only that the natural enemies are affected by pollution, and we choose the method to kill the pest without harming natural enemies. Sufficient conditions for global attractivity of the natural enemy-extinction periodic solution and permanence of the system are obtained. Numerical simulations are presented to confirm our theoretical results.

  15. Model reduction techniques for dynamics analysis of ultra-precision linear stage

    Institute of Scientific and Technical Information of China (English)

    Xuedong CHEN; Zhixin LI

    2009-01-01

    Spring-damping elements are used to simplify the internal interaction in the proposed finite element (FE) model of an ultra-precision linear Stage. The dynamics behavior is studied. The comparison between mode shapes from the eigenvalue analysis shows that the components, except the translator, can represent system dynamics characteristics. A reduction approach is used to simplify the system in a dynamic studied. There is little difference between the vibration mode and the response analysis. The experimental modal analysis proves the validity of the reduction approach, which can be generalized to the development and dynamics characteristic study of a complex system model to obviously save computational resource.

  16. Simulation model of a single-stage lithium bromide-water absorption cooling unit

    Science.gov (United States)

    Miao, D.

    1978-01-01

    A computer model of a LiBr-H2O single-stage absorption machine was developed. The model, utilizing a given set of design data such as water-flow rates and inlet or outlet temperatures of these flow rates but without knowing the interior characteristics of the machine (heat transfer rates and surface areas), can be used to predict or simulate off-design performance. Results from 130 off-design cases for a given commercial machine agree with the published data within 2 percent.

  17. 33 CFR 127.113 - Warning signs.

    Science.gov (United States)

    2010-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas § 127.113 Warning signs. (a) The marine transfer...

  18. 33 CFR 127.207 - Warning alarms.

    Science.gov (United States)

    2010-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.207 Warning alarms. (a) The...

  19. Communicating risk information and warnings

    Science.gov (United States)

    Mileti, D. S.

    1990-01-01

    Major advances have occurred over the last 20 years about how to effectively communicate risk information and warnings to the public. These lessons have been hard won. Knowledge has mounted on the finding from social scientific studies of risk communication failures, successes and those which fell somewhere in between. Moreover, the last 2 decades have borne witness to the brith, cultivation, and blossoming of information sharing between those physical scientists who discover new information about risk and those communcation scientists who trace its diffusion and then measure pbulic reaction. 

  20. Three-stage fermentation and kinetic modeling of bioflocculant by Corynebacterium glutamicum

    Institute of Scientific and Technical Information of China (English)

    Liang Shen; Zhongtao An; Qingbiao Li; Chuanyi Yao; Yajuan Peng; Yuanpeng Wang; Ruihua Lai; Xu Deng; Ning He

    2015-01-01

    Fermentation of bioflocculant with Corynebacterium glutamicum was studied by way of kinetic modeling. Lorentzian modified Logistic model, time-corrected Luedeking–Piret and Luedeking–Piret type models were pro-posed and applied to describe the cell growth, bioflocculant synthesis and consumption of substrates, with the correlation of initial biomass concentration and initial glucose concentration, respectively. The results showed that these models could well characterize the batch culture process of C. glutamicum at various initial glucose con-centrations from 10.0 to 17.5 g·L−1. The initial biomass concentration could shorten the lag time of cel growth, while the maximum biomass concentration was achieved only at the optimal initial glucose concentration of 16.22 g·L−1. A novel three-stage fed-batch strategy for bioflocculant production was developed based on the model prediction, in which the lag phase, quick biomass growth and bioflocculant production stages were sequentially proceeded with the adjustment of glucose concentration and dissolved oxygen. Biomass of 2.23 g·L−1 was obtained and bioflocculant concentration was enhanced to 176.32 mg·L−1, 18.62% and 403.63%higher than those in the batch process, respectively, indicating an efficient fed-batch culture strategy for bioflocculant production.

  1. Three-dimensional computer modeling of birds proepicardium on different stages of embryogenesis

    Directory of Open Access Journals (Sweden)

    Pototskaya O.Yu.

    2009-01-01

    Full Text Available As the proepicardium is the source of many cell populations of the mature heart, including cell components of coronary vessels, its investigation became actual last time. It is known, that there are some differences between birds and mammalian proepicardium; one of them consists in the way, in which they contact to myocardium: mammalian proepicardium produce vesicles, which contact to atrioventricular groove, wile in birds there is no vesicles and whole protrusions of proepicardium attach to the heart. But, recent years it became evident, that in rat proepicardium there are no vesicles during all stages of its existence, and in birds there is a proepicardium-like structure producing vesicles, which attach to the heart. Thus, the goal of our research was to characterize changes in the shape of proepicardium during bird’s embryogenesis. We used Cobb 500 chick embryos as a material; on the basis of pictures of proepicardium serial sections, with the help of Photoshop CS2, Amira for microscopy 5.0, 3ds max 8.0 computer programs, we made three-dimensional models of proepicardium on 15, 16, 17, 18, 21 stages of development by V.Hamburger, H.Hamilton, 1951. The most important changes in proepicardium shape observed from 14 to 20 stages of development. During this period proepicardium appeared on the right horn of sinus venous, enlarged and formed several crests, which contacted to atrioventricular groove. Coalescence of these crests led to dorsal mesocardium formation. From 21 to 27 stages of development there were no significant changes in proepicardium shape; the area of its contact to sinus venous was grown downwards while the area of contact to the heart enlarged. No vesicles, no “finger-like protrusions” were observed on any stage of bird’s development.

  2. 上市公司财务预警的正则化逻辑回归模型%Regularized Logistic Regression Model in Financial Early-warning System with Listed Companies

    Institute of Scientific and Technical Information of China (English)

    张恒; 秦宾; 许金凤

    2011-01-01

    LI norm penalized logistic regression model is proposed based on regularization technique of statistical theory, Logistic regression model and L2 regularized logistic regression model are established. Combining two years' financial data of Shanghai-Shenzhen stock ST companies and normal counterparts, simulating experiment is conducted to analyze the financial early-warning system of listed companies. The results demonstrate the good performance and predicting accuracy of LI logistic regression model%基于统计学习理论的正则化技术构建L1(一范数约束惩罚)正则化的逻辑回归(Logistic Regression)模型,同比建立了logistic回归模型和L2(二范数约束惩罚)正则化的logistic回归模型,结合沪深股市ST公司和正常公司的T-3年和T-2年财务数据进行仿真实验用于上市公司财务预警实证分析.实验结果表明L1正则化的logistic回归模型的有效性,并且在保证模型预测精度的同时提高模型了解释性.

  3. Applying the Health Belief Model in Explaining the Stages of Exercise Change in Older Adults

    Directory of Open Access Journals (Sweden)

    Sas-Nowosielski Krzysztof

    2016-12-01

    Full Text Available Introduction. The benefits of physical activity (PA have been so well documented that there is no doubt about the significance of PA for personal and social health. Several theoretical models have been proposed with a view to understanding the phenomenon of PA and other health behaviours. The purpose of this study was to evaluate if and how the variables suggested in the Health Belief Model (HBM determine physical activity stages of change in older adults. Material and methods. A total of 172 students of Universities of the Third Age aged 54 to 75 (mean = 62.89 ± 4.83 years agreed to participate in the study, filling out an anonymous survey measuring their stage of exercise change and determinants of health behaviours proposed by the HBM, including: perceived benefits of physical activity, perceived barriers to physical activity, perceived severity of diseases associated with sedentary lifestyle, perceived susceptibility to these diseases, and self-efficacy. Results. The results only partially support the hypothesis that the HBM predicts intentions and behaviours related to the physical activity of older adults. Only two variables were moderately-to-strongly related to stages of exercise change, namely perceived barriers and self-efficacy. Conclusion. Interventions aimed at informing older adults about the benefits of physical activity and the threats associated with sedentary lifestyle can be expected to have rather a weak influence on their readiness for physical activity.

  4. Structured model of bacterial growth and tests with activated sludge in a one-stage and two-stage chemostat

    NARCIS (Netherlands)

    Harder, A.

    1979-01-01

    A kinetic model for a growing culture of micro-organisms was developed that correlated the biochemical structure of cells with quantitative physiological behaviour. The three-compartment model was adequate for simulation of continuous, batch and transient experiments with activated sludge fed on van

  5. A novel data-driven prognostic model for staging of colorectal cancer.

    Science.gov (United States)

    Manilich, Elena A; Kiran, Ravi P; Radivoyevitch, Tomas; Lavery, Ian; Fazio, Victor W; Remzi, Feza H

    2011-11-01

    The aim of this study was to develop a novel prognostic model that captures complex interplay among clinical and histologic factors to predict survival of patients with colorectal cancer after a radical potentially curative resection. Survival data of 2,505 colon cancer and 2,430 rectal cancer patients undergoing radical colorectal resection between 1969 and 2007 were analyzed by random forest technology. The effect of TNM and non-TNM factors such as histologic grade, lymph node ratio (number positive/number resected), type of operation, neoadjuvant and adjuvant treatment, American Society of Anesthesiologists (ASA) class, and age in staging and prognosis were evaluated. A forest of 1,000 random survival trees was grown using log-rank splitting. Competing risk-adjusted random survival forest methods were used to maximize survival prediction and produce importance measures of the predictor variables. Competing risk-adjusted 5-year survival after resection of colon and rectal cancer was dominated by pT stage (ie, tumor infiltration depth) and lymph node ratio. Increased lymph node ratio was associated with worse survival within the same pT stage for both colon and rectal cancer patients. Whereas survival for colon cancer was affected by ASA grade, the type of resection and neoadjuvant therapy had a strong effect on rectal cancer survival. A similar pattern in predicted survival rates was observed for patients with fewer than 12 lymph nodes examined. Our model suggests that lymph node ratio remains a significant predictor of survival in this group. A novel data-driven methodology predicts the survival times of patients with colorectal cancer and identifies patterns of cancer characteristics. The methods lead to stage groupings that could redefine the composition of TNM in a simple and orderly way. The higher predictive power of lymph node ratio as compared with traditional pN lymph node stage has specific implications and may address the important question of accuracy

  6. Integrating Growth Stage Deficit Irrigation into a Process Based Crop Model

    Science.gov (United States)

    Lopez, Jose R.; Winter, Jonathan M.; Elliott, Joshua; Ruane, Alex C.; Porter, Cheryl; Hoogenboom, Gerrit

    2017-01-01

    Current rates of agricultural water use are unsustainable in many regions, creating an urgent need to identify improved irrigation strategies for water limited areas. Crop models can be used to quantify plant water requirements, predict the impact of water shortages on yield, and calculate water productivity (WP) to link water availability and crop yields for economic analyses. Many simulations of crop growth and development, especially in regional and global assessments, rely on automatic irrigation algorithms to estimate irrigation dates and amounts. However, these algorithms are not well suited for water limited regions because they have simplistic irrigation rules, such as a single soil-moisture based threshold, and assume unlimited water. To address this constraint, a new modeling framework to simulate agricultural production in water limited areas was developed. The framework consists of a new automatic irrigation algorithm for the simulation of growth stage based deficit irrigation under limited seasonal water availability; and optimization of growth stage specific parameters. The new automatic irrigation algorithm was used to simulate maize and soybean in Gainesville, Florida, and first used to evaluate the sensitivity of maize and soybean simulations to irrigation at different growth stages and then to test the hypothesis that water productivity calculated using simplistic irrigation rules underestimates WP. In the first experiment, the effect of irrigating at specific growth stages on yield and irrigation water use efficiency (IWUE) in maize and soybean was evaluated. In the reproductive stages, IWUE tended to be higher than in the vegetative stages (e.g. IWUE was 18% higher than the well watered treatment when irrigating only during R3 in soybean), and when rainfall events were less frequent. In the second experiment, water productivity (WP) was significantly greater with optimized irrigation schedules compared to non-optimized irrigation schedules in

  7. Population balance modelling and multi-stage optimal control of a pulsed spray fluidized bed granulation.

    Science.gov (United States)

    Liu, Huolong; Li, Mingzhong

    2014-07-01

    In this work, one-dimensional population balance models (PBMs) have been developed to model a pulsed top-spray fluidized bed granulation. The developed PBMs have linked the key binder solution spray operating factors of the binder spray rate, atomizing air pressure and pulsed frequency of spray with the granule properties to predict granule growth behaviour in the pulsed spray fluidized bed granulation process at different operating conditions with accuracy. A multi-stage open optimal control strategy based on the developed PBMs was proposed to reduce the model mismatch, in which through adjusting the trajectory of the evolution of the granule size distribution at predefined sample intervals, to determine the optimal operating variables related to the binder spray including the spray rate of binding liquid, atomizing air pressure and pulsed frequency of spray. The effectiveness of the proposed modelling and multi-stage open optimal control strategies has been validated by experimental and simulation tests. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. A decision-analytic model for early stage breast cancer: lumpectomy vs mastectomy.

    Science.gov (United States)

    Büyükdamgaci-Alogan, G; Elele, T; Hayran, M; Erman, M; Kiliçkap, S

    2008-01-01

    The purpose was to construct a decision model that incorporated patient preferences over differing health state prospects and to analyze the decision context of early stage breast cancer patients in relation to two main surgical treatment options. A Markov chain was constructed to project the clinical history of breast carcinoma following surgery. A Multi Attribute Utility Model was developed for outcome evaluation. Transition probabilities were obtained by using subjective probability assessment. This study was performed on the sample population of female university students and utilities were elicited from these healthy volunteers. The results were validated by using Standard Gamble technique. Finally, Monte Carlo Simulation was utilized in Treeage-Pro 2006-Suit software program in order to calculate expected utility generated by each treatment option. The results showed that, if the subject had mastectomy, mean value for the quality adjusted life years gained was 6.42; on the other hand, if the preference was lumpectomy, it was 7.00 out of a possible 10 years. Sensitivity analysis on transition probabilities to local recurrence and salvaged states was performed and two threshold values were observed. Additionally, sensitivity analysis on utilities showed that the model was more sensitive to no evidence of disease state; however, was not sensitive to utilities of local recurrence and salvaged states. The decision model was developed with reasonable success for early stage breast cancer patients, and tested by using general public data. The results obtained from these data showed that lumpectomy was more favourable for these participants.

  9. New higher-order Godunov code for modelling performance of two-stage light gas guns

    Science.gov (United States)

    Bogdanoff, D. W.; Miller, R. J.

    1995-01-01

    A new quasi-one-dimensional Godunov code for modeling two-stage light gas guns is described. The code is third-order accurate in space and second-order accurate in time. A very accurate Riemann solver is used. Friction and heat transfer to the tube wall for gases and dense media are modeled and a simple nonequilibrium turbulence model is used for gas flows. The code also models gunpowder burn in the first-stage breech. Realistic equations of state (EOS) are used for all media. The code was validated against exact solutions of Riemann's shock-tube problem, impact of dense media slabs at velocities up to 20 km/sec, flow through a supersonic convergent-divergent nozzle and burning of gunpowder in a closed bomb. Excellent validation results were obtained. The code was then used to predict the performance of two light gas guns (1.5 in. and 0.28 in.) in service at the Ames Research Center. The code predictions were compared with measured pressure histories in the powder chamber and pump tube and with measured piston and projectile velocities. Very good agreement between computational fluid dynamics (CFD) predictions and measurements was obtained. Actual powder-burn rates in the gun were found to be considerably higher (60-90 percent) than predicted by the manufacturer and the behavior of the piston upon yielding appears to differ greatly from that suggested by low-strain rate tests.

  10. CONCEPTUAL MODEL OF STAGED FORMATION OF AN INDIVIDUAL CREATIVE METHOD OF AN ARCHITECT

    Directory of Open Access Journals (Sweden)

    Kolstet O. A.

    2016-03-01

    Full Text Available The article considers the development of a model of gradual formation of individual creative method of an architect in the propaedeutic level since preuniversity stage (with the involvement of distance training and its continuity of the first courses of architectural disciplines in high school in terms of the Rostov school of architecture. There have been examined some studies by Nechaev N.N. and Sulimenko S.D. at the architectural department of the Far Eastern Technical University, that have revealed a non-linear nature of the formation of spatial thinking and the need to develop a systematic approach in the propaedeutic phase of training. These studies formed the basis of a new conceptual model. A list of the input competence requirements for applicants entering architectural universities to ensure the quality of training at university propaedeutic phase is done. Methodological feature of the Rostov school of architecture, which is both a synthesis of problems in the field of threedimensional composition and design problems is revealed, as well as a combination of methods of modeling and manual architectural drawing with computer graphics (SketchUp, CorelDraw, Photoshop, AutoCad. The schemes of a number of separate stages of the formation of individual creative method of the architect, as well as the general scheme of the whole conceptual model is given

  11. A multi-stage compartmental model for HIV-infected individuals: I--waiting time approach.

    Science.gov (United States)

    Billard, L; Dayananda, P W A

    2014-03-01

    Traditionally, epidemic processes have focused on establishing systems of differential-difference equations governing the number of individuals at each stage of the epidemic. Except for simple situations such as when transition rates are linear, these equations are notoriously intractable mathematically. In this work, the process is described as a compartmental model. The model also allows for individuals to go directly from any prior compartment directly to a final stage corresponding to death. This allows for the possibility that individuals can die earlier due to some non-disease related cause. Then, the model is based on waiting times in each compartment. Survival probabilities of moving from a given compartment to another compartment are established. While our approach can be used for general epidemic processes, our framework is for the HIV/AIDS process. It is then possible to establish the impact of the HIV/AIDS epidemic process on, e.g., insurance premiums and payouts and health-care costs. The effect of changing model parameter values on these entities is investigated.

  12. A two-stage storage routing model for green roof runoff detention.

    Science.gov (United States)

    Vesuviano, Gianni; Sonnenwald, Fred; Stovin, Virginia

    2014-01-01

    Green roofs have been adopted in urban drainage systems to control the total quantity and volumetric flow rate of runoff. Modern green roof designs are multi-layered, their main components being vegetation, substrate and, in almost all cases, a separate drainage layer. Most current hydrological models of green roofs combine the modelling of the separate layers into a single process; these models have limited predictive capability for roofs not sharing the same design. An adaptable, generic, two-stage model for a system consisting of a granular substrate over a hard plastic 'egg box'-style drainage layer and fibrous protection mat is presented. The substrate and drainage layer/protection mat are modelled separately by previously verified sub-models. Controlled storm events are applied to a green roof system in a rainfall simulator. The time-series modelled runoff is compared to the monitored runoff for each storm event. The modelled runoff profiles are accurate (mean Rt(2) = 0.971), but further characterization of the substrate component is required for the model to be generically applicable to other roof configurations with different substrate.

  13. Modelled interglacial carbon cycle dynamics during the Holocene, the Eemian and Marine Isotope Stage (MIS) 11

    Science.gov (United States)

    Kleinen, Thomas; Brovkin, Victor; Munhoven, Guy

    2016-11-01

    Trends in the atmospheric concentration of CO2 during three recent interglacials - the Holocene, the Eemian and Marine Isotope Stage (MIS) 11 - are investigated using an earth system model of intermediate complexity, which we extended with process-based modules to consider two slow carbon cycle processes - peat accumulation and shallow-water CaCO3 sedimentation (coral reef formation). For all three interglacials, model simulations considering peat accumulation and shallow-water CaCO3 sedimentation substantially improve the agreement between model results and ice core CO2 reconstructions in comparison to a carbon cycle set-up neglecting these processes. This enables us to model the trends in atmospheric CO2, with modelled trends similar to the ice core data, forcing the model only with orbital and sea level changes. During the Holocene, anthropogenic CO2 emissions are required to match the observed rise in atmospheric CO2 after 3 ka BP but are not relevant before this time. Our model experiments show a considerable improvement in the modelled CO2 trends by the inclusion of the slow carbon cycle processes, allowing us to explain the CO2 evolution during the Holocene and two recent interglacials consistently using an identical model set-up.

  14. A hybrid deep neural network and physically based distributed model for river stage prediction

    Science.gov (United States)

    hitokoto, Masayuki; sakuraba, Masaaki

    2016-04-01

    We developed the real-time river stage prediction model, using the hybrid deep neural network and physically based distributed model. As the basic model, 4 layer feed-forward artificial neural network (ANN) was used. As a network training method, the deep learning technique was applied. To optimize the network weight, the stochastic gradient descent method based on the back propagation method was used. As a pre-training method, the denoising autoencoder was used. Input of the ANN model is hourly change of water level and hourly rainfall, output data is water level of downstream station. In general, the desirable input of the ANN has strong correlation with the output. In conceptual hydrological model such as tank model and storage-function model, river discharge is governed by the catchment storage. Therefore, the change of the catchment storage, downstream discharge subtracted from rainfall, can be the potent input candidate of the ANN model instead of rainfall. From this point of view, the hybrid deep neural network and physically based distributed model was developed. The prediction procedure of the hybrid model is as follows; first, downstream discharge was calculated by the distributed model, and then estimates the hourly change of catchment storage form rainfall and calculated discharge as the input of the ANN model, and finally the ANN model was calculated. In the training phase, hourly change of catchment storage can be calculated by the observed rainfall and discharge data. The developed model was applied to the one catchment of the OOYODO River, one of the first-grade river in Japan. The modeled catchment is 695 square km. For the training data, 5 water level gauging station and 14 rain-gauge station in the catchment was used. The training floods, superior 24 events, were selected during the period of 2005-2014. Prediction was made up to 6 hours, and 6 models were developed for each prediction time. To set the proper learning parameters and network

  15. Graphic Warning Labels Elicit Affective and Thoughtful Responses from Smokers: Results of a Randomized Clinical Trial.

    Directory of Open Access Journals (Sweden)

    Abigail T Evans

    Full Text Available Observational research suggests that placing graphic images on cigarette warning labels can reduce smoking rates, but field studies lack experimental control. Our primary objective was to determine the psychological processes set in motion by naturalistic exposure to graphic vs. text-only warnings in a randomized clinical trial involving exposure to modified cigarette packs over a 4-week period. Theories of graphic-warning impact were tested by examining affect toward smoking, credibility of warning information, risk perceptions, quit intentions, warning label memory, and smoking risk knowledge.Adults who smoked between 5 and 40 cigarettes daily (N = 293; mean age = 33.7, did not have a contra-indicated medical condition, and did not intend to quit were recruited from Philadelphia, PA and Columbus, OH. Smokers were randomly assigned to receive their own brand of cigarettes for four weeks in one of three warning conditions: text only, graphic images plus text, or graphic images with elaborated text.Data from 244 participants who completed the trial were analyzed in structural-equation models. The presence of graphic images (compared to text-only caused more negative affect toward smoking, a process that indirectly influenced risk perceptions and quit intentions (e.g., image->negative affect->risk perception->quit intention. Negative affect from graphic images also enhanced warning credibility including through increased scrutiny of the warnings, a process that also indirectly affected risk perceptions and quit intentions (e.g., image->negative affect->risk scrutiny->warning credibility->risk perception->quit intention. Unexpectedly, elaborated text reduced warning credibility. Finally, graphic warnings increased warning-information recall and indirectly increased smoking-risk knowledge at the end of the trial and one month later.In the first naturalistic clinical trial conducted, graphic warning labels are more effective than text-only warnings

  16. Comparing stochastic differential equations and agent-based modelling and simulation for early-stage cancer.

    Science.gov (United States)

    Figueredo, Grazziela P; Siebers, Peer-Olaf; Owen, Markus R; Reps, Jenna; Aickelin, Uwe

    2014-01-01

    There is great potential to be explored regarding the use of agent-based modelling and simulation as an alternative paradigm to investigate early-stage cancer interactions with the immune system. It does not suffer from some limitations of ordinary differential equation models, such as the lack of stochasticity, representation of individual behaviours rather than aggregates and individual memory. In this paper we investigate the potential contribution of agent-based modelling and simulation when contrasted with stochastic versions of ODE models using early-stage cancer examples. We seek answers to the following questions: (1) Does this new stochastic formulation produce similar results to the agent-based version? (2) Can these methods be used interchangeably? (3) Do agent-based models outcomes reveal any benefit when compared to the Gillespie results? To answer these research questions we investigate three well-established mathematical models describing interactions between tumour cells and immune elements. These case studies were re-conceptualised under an agent-based perspective and also converted to the Gillespie algorithm formulation. Our interest in this work, therefore, is to establish a methodological discussion regarding the usability of different simulation approaches, rather than provide further biological insights into the investigated case studies. Our results show that it is possible to obtain equivalent models that implement the same mechanisms; however, the incapacity of the Gillespie algorithm to retain individual memory of past events affects the similarity of some results. Furthermore, the emergent behaviour of ABMS produces extra patters of behaviour in the system, which was not obtained by the Gillespie algorithm.

  17. Comparing stochastic differential equations and agent-based modelling and simulation for early-stage cancer.

    Directory of Open Access Journals (Sweden)

    Grazziela P Figueredo

    Full Text Available There is great potential to be explored regarding the use of agent-based modelling and simulation as an alternative paradigm to investigate early-stage cancer interactions with the immune system. It does not suffer from some limitations of ordinary differential equation models, such as the lack of stochasticity, representation of individual behaviours rather than aggregates and individual memory. In this paper we investigate the potential contribution of agent-based modelling and simulation when contrasted with stochastic versions of ODE models using early-stage cancer examples. We seek answers to the following questions: (1 Does this new stochastic formulation produce similar results to the agent-based version? (2 Can these methods be used interchangeably? (3 Do agent-based models outcomes reveal any benefit when compared to the Gillespie results? To answer these research questions we investigate three well-established mathematical models describing interactions between tumour cells and immune elements. These case studies were re-conceptualised under an agent-based perspective and also converted to the Gillespie algorithm formulation. Our interest in this work, therefore, is to establish a methodological discussion regarding the usability of different simulation approaches, rather than provide further biological insights into the investigated case studies. Our results show that it is possible to obtain equivalent models that implement the same mechanisms; however, the incapacity of the Gillespie algorithm to retain individual memory of past events affects the similarity of some results. Furthermore, the emergent behaviour of ABMS produces extra patters of behaviour in the system, which was not obtained by the Gillespie algorithm.

  18. 基于Logistic回归模型的房地产上市公司财务危机预警研究%Financial Early-warning for Real Estate Listed Company Based on Logistic Regression Model

    Institute of Scientific and Technical Information of China (English)

    许珂; 卢海

    2012-01-01

    近年来房价不断上涨,我国政府采取了一系列紧缩政策来控制房价,对房地产上市公司产生了巨大影响,有部分公司因为资金链断裂而陷入困境。因此,对房地产上市公司的财务预警十分重要。文章采用非参数检验的方法,从反映企业各方面能力的20个财务指标中筛选出能显著区别ST和非ST上市公司的指标,建立Logistic回归模型,利用SPSS软件,对房地产上市公司的财务危机预警进行了研究。研究结果表明,基于Logistic回归模型的财务危机预警模型效果较好,具有良好的预测准确度。%In recent years,the housing prices keep rocketing,thus the Chinese government tried a series of means to stabilize the price,which had a tremendous impact on some companies,leading to their falling into trouble due to funding strand breaks.Therefore,the financial early warning is very important for real estate listed companies.The paper uses non-parameter test based on 20 financial ratios,in order to find financial ratios which can significantly indentify the different between ST and non-ST companies.And then it studies the financial early-warning for real estate listed company based on logistic regression model by using the SPSS software.The results show that the model based on logistic regression model is of good effect,and has good predictive accuracy.

  19. A Simple Early Warning System for Evaluating the Credit Portfolio's Quality

    Directory of Open Access Journals (Sweden)

    Nicolae Dardac

    2009-05-01

    Full Text Available The last decade has witnessed the development of a vast literature devoted to the study of several phenomena like banking crises or episodes of vulnerability and distress, characterized by inadequate capitalization, impairment of the asset quality and of the credit institutions' rating. The purpose of this study is to design an early warning system in order to highlight at an earlier stage the likelihood of deterioration of the Romanian banking system credit portfolio's quality. We have applied an econometric model which constitutes a reference for this type of analysis, having as purpose the identification of a significant correlation between increasing weight of bad loans in total assets, on the one hand, and a number of macroeconomic variables and indicators of the banking system, on the other hand.

  20. The GRENE-TEA Model Intercomparison Project (GTMIP: overview and experiment protocol for Stage 1

    Directory of Open Access Journals (Sweden)

    S. Miyazaki

    2015-04-01

    Full Text Available As part of the terrestrial branch of the Japan-funded Arctic Climate Change Research Project (GRENE-TEA, which aims to clarify the role and function of the Arctic terrestrial system in the climate system, and assess the influence of its changes on a global scale, this model intercomparison project (GTMIP is planned and being conducted to (1 enhance communication and understanding between the "minds and hands" (i.e., between the modelling and field scientists and (2 assess the uncertainty and variations stemming from variability in model implementation/design and in model outputs due to climatic and historical conditions in the Arctic terrestrial regions. This paper provides an overview and the experiment protocol of Stage 1 of the project, site simulations driven by statistically fitted data created using the GRENE-TEA site observations for the last three decades. The target metrics for the model evaluation cover key processes in both physics and biogeochemistry, including energy budgets, snow, permafrost, phenology, and carbon budgets. The preliminary results on four metrics (annual mean latent heat flux, annual maximum snow depth, gross primary production, and net ecosystem production already demonstrate the range of variations in reproducibility among existing models and sites. Full analysis on annual as well as seasonal time scales, to be conducted upon completion of model outputs submission, will delineate inter-dependence among the key processes, and provide the clue for improving the model performance.

  1. 30 CFR 75.208 - Warning devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Warning devices. 75.208 Section 75.208 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Roof Support § 75.208 Warning devices. Except during...

  2. 46 CFR 154.1830 - Warning sign.

    Science.gov (United States)

    2010-10-01

    ... (2) Facing outboard towards the water so that the sign may be seen from the water. (b) Except as provided in paragraph (e) of this section, each warning sign must have the following words: (1) Warning. (2) Dangerous Cargo. (3) No Visitors. (4) No Smoking. (5) No Open Lights. (c) Each letter in the words on...

  3. An Infrastructure for a Traffic Warning System

    DEFF Research Database (Denmark)

    Brønsted, Jeppe; Hansen, Klaus Marius; Kristensen, Lars Michael

    2005-01-01

    The LIWAS Trafc Warning System aims at providingearly warning to vehicles about road conditions, such aswhether the road is slippery. The LIWAS system is currentlybeing developed and consists of two main parts:sensors for determining the state of the road and a communicationinfrastructure support...

  4. An Infrastructure for a Traffic Warning System

    DEFF Research Database (Denmark)

    Brønsted, Jeppe; Hansen, Klaus Marius; Kristensen, Lars Michael

    2005-01-01

    The LIWAS Trafc Warning System aims at providingearly warning to vehicles about road conditions, such aswhether the road is slippery. The LIWAS system is currentlybeing developed and consists of two main parts:sensors for determining the state of the road and a communicationinfrastructure support...

  5. Modeling Humans as Reinforcement Learners: How to Predict Human Behavior in Multi-Stage Games

    Science.gov (United States)

    Lee, Ritchie; Wolpert, David H.; Backhaus, Scott; Bent, Russell; Bono, James; Tracey, Brendan

    2011-01-01

    This paper introduces a novel framework for modeling interacting humans in a multi-stage game environment by combining concepts from game theory and reinforcement learning. The proposed model has the following desirable characteristics: (1) Bounded rational players, (2) strategic (i.e., players account for one anothers reward functions), and (3) is computationally feasible even on moderately large real-world systems. To do this we extend level-K reasoning to policy space to, for the first time, be able to handle multiple time steps. This allows us to decompose the problem into a series of smaller ones where we can apply standard reinforcement learning algorithms. We investigate these ideas in a cyber-battle scenario over a smart power grid and discuss the relationship between the behavior predicted by our model and what one might expect of real human defenders and attackers.

  6. A behavioral stages model of classical (Pavlovian) conditioning: application to cognitive aging.

    Science.gov (United States)

    Powell, D A

    1999-01-01

    In the present article, it is argued that a five-stage sequential model of the behavioral and neurophysiological events that occur when organisms are exposed to signals predicting significant events suggests that classical conditioning produces multiple memory traces involving both excitatory and inhibitory processes. Further, these multiple brain structures and associated neurophysiological mechanisms are beginning to be understood; thus, using Pavlovian conditioning techniques to study aging and cognitive functions may provide insights into which brain structures or mechanisms are responsible for more general age-related declines in associative learning and memory. The evidence for this model is briefly reviewed and studies suggesting age-related effects on classical conditioning of various response systems are described within the context of the brain structures implicated by the model.

  7. Spatially-explicit matrix models. A mathematical analysis of stage-structured integrodifference equations.

    Science.gov (United States)

    Lutscher, Frithjof; Lewis, Mark A

    2004-03-01

    This paper is concerned with mathematical analysis of the 'critical domain-size' problem for structured populations. Space is introduced explicitly into matrix models for stage-structured populations. Movement of individuals is described by means of a dispersal kernel. The mathematical analysis investigates conditions for existence, stability and uniqueness of equilibrium solutions as well as some bifurcation behaviors. These mathematical results are linked to species persistence or extinction in connected habitats of different sizes or fragmented habitats; hence the framework is given for application of such models to ecology. Several approximations which reduce the complexity of integrodifference equations are given. A simple example is worked out to illustrate the analytical results and to compare the behavior of the integrodifference model to that of the approximations.

  8. ADM1-based modeling of methane production from acidified sweet sorghum extractin a two stage process

    DEFF Research Database (Denmark)

    Antonopoulou, Georgia; Gavala, Hariklia N.; Skiadas, Ioannis

    2012-01-01

    The present study focused on the application of the Anaerobic Digestion Model 1 οn the methane production from acidified sorghum extract generated from a hydrogen producing bioreactor in a two-stage anaerobic process. The kinetic parameters for hydrogen and volatile fatty acids consumption were...... estimated through fitting of the model equations to the data obtained from batch experiments. The simulation of the continuous reactor performance at all HRTs tested (20, 15 and 10d) was very satisfactory. Specifically, the largest deviation of the theoretical predictions against the experimental data...... was 12% for the methane production rate at the HRT of 20d while the deviation values for the 15 and 10 d HRT were 1.9% and 1.1%, respectively. The model predictions regarding pH, methane percentage in the gas phase and COD removal were in very good agreement with the experimental data with a deviation...

  9. Mathematical modeling of the heat treatment and combustion of a coal particle. III. Volatile escape stage

    Science.gov (United States)

    Enkhjargal, Kh.; Salomatov, V. V.

    2011-05-01

    The present paper is a continuation of previous publications of the authors in this journal in which two phases of the multistage process of combustion of a coal particle were considered in detail with the help of mathematical modeling: its radiation-convection heating and drying. In the present work, the escape dynamics of volatiles is investigated. The physico-mathematical model of the thermodestruction of an individual coal particle with a dominant influence of endothermal effects has been formulated. Approximate-analytical solutions of this model that are of paramount importance for detailed analysis of the influence of the physical and regime parameters on the escape dynamics of volatiles have been found. The results obtained form the basis for engineering calculations of the volatile escape stage and can be used successfully in the search for effective regimes of burning of various solid fuels, in particular, Shivé-Ovoos coal of Mongolia.

  10. MODELING OF THE DIVERSION CHANNEL CLOSURE FOR THE THIRD STAGE OF THE THREE GORGES PROJECT

    Institute of Scientific and Technical Information of China (English)

    Guangqian WANG; Baosheng WU; Junqiang XIA

    2004-01-01

    The closure of third stage diversion channel for the Three Gorges Dam is characterized by large closure discharge, large drop in water surface, and high gap velocity. 1D and 2D flow mathematical models were used in this paper to simulate the hydraulic conditions during the closure. The variation of discharge in the diversion channel and the drops in water surface shared by the upstream and downstream cofferdams were computed using the 1D model, and the detailed hydraulic patterns in the diversion channel were simulated using the 2D model. The computed results indicate that the designed closure scheme for discharge of 9,010 m3/s was feasible for construction, while the designed closure scheme for discharge of 12,200 m3/s was inapplicable.

  11. Effect of the initial stage of annealing on modeling of enthalpy relaxation in a hyperquenched glass

    DEFF Research Database (Denmark)

    Zhang, Yanfei; Guo, Xiaoju; Yue, Yuanzheng

    2013-01-01

    relaxation in both HQG and AHQG during the initial stage of both the sub-Tg and above-Tg annealing cannot be captured by the existing models. In this Letter we show that the combination of a modified stretched exponential equation [M. Peyron, et al., J. Magn. Reson, Series A 118 (1996) 214] and the recently......One of the major challenges in glass relaxation study is to establish a universal model describing the enthalpy relaxation in both the hyperquenched glass (HQG) (i.e., far from equilibrium) and the partially annealed hyperquenched glass(AHQG). In particular, the detailed features of the enthalpy...... proposed composite relaxation function [L. Hornboell, et al., Chem. Phys. Lett. 1-3 (2010) 37] is a reasonable approach for describing those features. In addition, our modeling results imply that the structural heterogeneity plays a crucial role in relaxation of HQG....

  12. Stage-dependent model for Hantavirus infection: The effect of the initial infection-free period

    Science.gov (United States)

    Reinoso, José A.; de la Rubia, F. Javier

    2013-04-01

    We propose a stage-dependent model with constant delay to study the effect of the initial infection-free period on the spread of Hantavirus infection in rodents. We analyze the model under various extreme weather conditions, in the context of the El Niño-La Niña Southern Oscillation phenomenon, and show how these variations determine the evolution of the system significantly. When the scenario corresponds to El Niño, the system presents a demographic explosion and a delayed outbreak of Hantavirus infection, whereas if the scenario is the opposite there is a rapid decline of the population, but with a possible persistence period that may imply a considerable risk for public health, a fact that is in agreement with available field data. We use the model to simulate a historical evolution that resembles the processes that occurred in the 1990s.

  13. Lack of miRNA misregulation at early pathological stages in Drosophila neurodegenerative disease models

    Directory of Open Access Journals (Sweden)

    Anita eReinhardt

    2012-10-01

    Full Text Available Late onset neurodegenerative diseases represent a major public health concern as the population in many countries ages. Both frequent diseases such as Alzheimer disease (AD, 14% incidence for 80-84 year old Europeans or Parkinson disease (PD, 1.4% prevalence for > 55 years old share, with other low-incidence neurodegenerative pathologies such as spinocerebellar ataxias (SCAs, 0.01% prevalence and frontotemporal lobar degeneration (FTLD, 0.02% prevalence, a lack of efficient treatment in spite of important research efforts. Besides significant progress, studies with animal models have revealed unexpected complexities in the degenerative process, emphasizing a need to better understand the underlying pathological mechanisms. Recently, microRNAs, a class of small regulatory non-coding RNAs, have been implicated in some neurodegenerative diseases. The current data supporting a role of miRNAs in PD, tauopathies, dominant ataxias and FTLD will first be discussed to emphasize the different levels of the pathological processes which may be affected by miRNAs. To investigate a potential involvement of miRNA dysregulation in the early stages of these neurodegenerative diseases we have used Drosophila models for 7 diseases (PD, 3 FTLD, 3 dominant ataxias that recapitulate many features of the human diseases. We performed deep sequencing of head small RNAs after 3 days of pathological protein expression in the fly head neurons. We found no evidence for a statistically significant difference in miRNA expression in this early stage of the pathological process. In addition, we could not identify small non coding CAG repeat RNAs (sCAG in polyQ disease models. Thus our data suggest that transcriptional deregulation of miRNAs or sCAG is unlikely to play a significant role in the initial stages of neurodegenerative diseases.

  14. Proteomics-based systems biology modeling of bovine germinal vesicle stage oocyte and cumulus cell interaction.

    Directory of Open Access Journals (Sweden)

    Divyaswetha Peddinti

    Full Text Available BACKGROUND: Oocytes are the female gametes which establish the program of life after fertilization. Interactions between oocyte and the surrounding cumulus cells at germinal vesicle (GV stage are considered essential for proper maturation or 'programming' of oocytes, which is crucial for normal fertilization and embryonic development. However, despite its importance, little is known about the molecular events and pathways involved in this bidirectional communication. METHODOLOGY/PRINCIPAL FINDINGS: We used differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT on bovine GV oocyte and cumulus cells and identified 811 and 1247 proteins in GV oocyte and cumulus cells, respectively; 371 proteins were significantly differentially expressed between each cell type. Systems biology modeling, which included Gene Ontology (GO and canonical genetic pathway analysis, showed that cumulus cells have higher expression of proteins involved in cell communication, generation of precursor metabolites and energy, as well as transport than GV oocytes. Our data also suggests a hypothesis that oocytes may depend on the presence of cumulus cells to generate specific cellular signals to coordinate their growth and maturation. CONCLUSIONS/SIGNIFICANCE: Systems biology modeling of bovine oocytes and cumulus cells in the context of GO and protein interaction networks identified the signaling pathways associated with the proteins involved in cell-to-cell signaling biological process that may have implications in oocyte competence and maturation. This first comprehensive systems biology modeling of bovine oocytes and cumulus cell proteomes not only provides a foundation for signaling and cell physiology at the GV stage of oocyte development, but are also valuable for comparative studies of other stages of oocyte development at the molecular level.

  15. Modelling and Control of the Multi-stage Cable Pulley-driven Flexible-joint Robot

    Directory of Open Access Journals (Sweden)

    Phongsaen Pitakwatchara

    2014-07-01

    Full Text Available This work is concerned with the task space impedance control of a robot driven through a multi-stage nonlinear flexible transmission system. Specifically, a two degrees-of-freedom cable pulley-driven flexible-joint robot is considered. Realistic modelling of the system is developed within the bond graph modelling framework. The model captures the nonlinear compliance behaviour of the multi-stage cable pulley transmission system, the spring effect of the augmented counterbalancing mechanism, the major loss throughout the system elements, and the typical inertial dynamics of the robot. Next, a task space impedance controller based on limited information about the angle and the current of the motors is designed. The motor current is used to infer the transmitted torque, by which the motor inertia may be modulated. The motor angle is employed to estimate the stationary distal robot link angle and the robot joint velocity. They are used in the controller to generate the desired damping force and to shape the potential energy of the flexible joint robot system to the desired configuration. Simulation and experimental results of the controlled system signify the competency of the proposed control law.

  16. Evaluation of a prognostic model for risk of relapse in stage I seminoma surveillance.

    Science.gov (United States)

    Chung, Peter; Daugaard, Gedske; Tyldesley, Scott; Atenafu, Eshetu G; Panzarella, Tony; Kollmannsberger, Christian; Warde, Padraig

    2015-01-01

    A prognostic model for relapse risk in stage I seminoma managed by surveillance after orchiectomy has been developed but has not been independently validated. Individual data on 685 stage I seminoma surveillance patients managed between 1998 and 2005 at three cancer centers were retrospectively analyzed. Variables including age and pathology of the primary tumor: small vessel invasion, tumor size, and invasion of rete testis were analyzed. Specifically median tumor size and rete testis invasion was tested to evaluate the performance of the published model. Median follow-up was 3.85 years (0.1-10.29), 88 patients relapsed and 5-year relapse-free rate was 85%. In univariate analysis, median tumor size (seminoma surveillance as we were unable to validate the previously developed model. However, primary tumor size retained prognostic importance and a scale of relapse risk based on the unit increment of tumor size was developed to help guide patients and clinicians in decision making. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  17. Non-linear Langevin model for the early-stage dynamics of electrospinning jets

    CERN Document Server

    Lauricella, Marco; Pisignano, Dario; Succi, Sauro

    2015-01-01

    We present a non-linear Langevin model to investigate the early-stage dynamics of electrified polymer jets in electrospinning experiments. In particular, we study the effects of air drag force on the uniaxial elongation of the charged jet, right after ejection from the nozzle. Numerical simulations show that the elongation of the jet filament close to the injection point is significantly affected by the non-linear drag exerted by the surrounding air. These result provide useful insights for the optimal design of current and future electrospinning experiments.

  18. Hormone-dependent Model on Seed Germination Sensitive to Growth Stage

    Science.gov (United States)

    Kawaguchi, Satoshi; Mimura, Masayasu; Ohya, Tomoyuki; Okabe, Hirotaka; Kai, Shoichi

    2000-04-01

    In the germination of seeds, there often observes cluster-formation of well-grown roots and the edge effect phenomenon.During germination and growth before starting photosynthesis, direct interaction such as competition for nutrition among hosts is rather weak because of self-supplying of nutrition.Instead, hormones play an important role and may cause the above experimental observations.In order to understand these aspects, we propose a growth model for root.The hormone effect and its growth-stage-dependent sensitivity are taken into consideration.It is discussed how the growth process of grouping roots is influenced by exogenous hormones secreted from roots.

  19. Dynamic behaviors of a delayed HIV model with stage-structure

    Science.gov (United States)

    Hao, Pengmiao; Fan, Dejun; Wei, Junjie; Liu, Qinghe

    2012-12-01

    Inspired by a simulation specific to a delayed HIV model with stage-structure, some dynamic behaviors are studied in this paper, including global stability of disease-free equilibrium and local Hopf bifurcation when taking the delay as a parameter. The corresponding characteristic equation is a transcendental equation, with the parameters delay-dependent, thus we use the conventional analysis introduced by Beretta and Kuang to obtain sufficient conditions to the existence of Hopf bifurcation. Then some properties of Hopf bifurcation such as direction, stability and period are determined, and several examples illustrate our results.

  20. Modeling and Nonlinear Control of Electric Power Stage in Hybrid Electric Vehicle

    DEFF Research Database (Denmark)

    Tahri, A.; El Fadil, H.; Guerrero, Josep M.;

    2014-01-01

    This paper deals with the problem of modeling and controlling the electric power stage of hybrid electric vehicle. The controlled system consists of a fuel cell (FC) as a main source, a supercapacitor as an auxiliary source, two DC-DC power converters, an inverter and a traction induction motor...... based approach is used to control the DC/DC power converters associated with the DC sources, the backstepping technique combined with the field oriented control strategy are invoked in order to control the induction motor. It is formally shown, using a theoretical analysis and simulation results...

  1. A Model of Isotope Separation in Cells at the Early Stages of Evolution.

    Science.gov (United States)

    Melkikh, A V; Bokunyaeva, A O

    2016-03-01

    The separation of the isotopes of certain ions can serve as an important criterion for the presence of life in the early stages of its evolution. A model of the separation of isotopes during their transport through the cell membrane is constructed. The dependence of the selection coefficient on various parameters is found. In particular, it is shown that the maximum efficiency of the transport of ions corresponds to the minimum enrichment coefficient. At the maximum enrichment, the efficiency of the transport system approaches ½. Calculated enrichment coefficients are compared with experimentally obtained values for different types of cells, and the comparison shows a qualitative agreement between these quantities.

  2. Dynamic modeling of a three-stage low-temperature ethanol reformer for fuel cell application

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Vanesa M.; Serra, Maria [Institut de Robotica i Informatica Industrial (CSIC-UPC), Llorens i Artigas 4-6, 08028 Barcelona (Spain); Lopez, Eduardo; Llorca, Jordi [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain)

    2009-07-01

    A low-temperature ethanol reformer based on a cobalt catalyst for the production of hydrogen has been designed aiming the feed of a fuel cell for an autonomous low-scale power production unit. The reformer comprises three stages: ethanol dehydrogenation to acetaldehyde and hydrogen over SnO{sub 2} followed by acetaldehyde steam reforming over Co(Fe)/ZnO catalyst and water gas shift reaction. Kinetic data have been obtained under different experimental conditions and a dynamic model has been developed for a tubular reformer loaded with catalytic monoliths for the production of the hydrogen required to feed a 1 kW PEMFC. (author)

  3. Flood and landslide warning based on rainfall thresholds and soil moisture indexes: the HEWS (Hydrohazards Early Warning System for Sicily

    Directory of Open Access Journals (Sweden)

    G. Brigandì

    2017-09-01

    Full Text Available The main focus of the paper is to present a flood and landslide early warning system, named HEWS (Hydrohazards Early Warning System, specifically developed for the Civil Protection Department of Sicily, based on the combined use of rainfall thresholds, soil moisture modelling and quantitative precipitation forecast (QPF. The warning system is referred to 9 different Alert Zones in which Sicily has been divided into and based on a threshold system of three different increasing critical levels: ordinary, moderate and high. In this system, for early flood warning, a Soil Moisture Accounting (SMA model provides daily soil moisture conditions, which allow to select a specific set of three rainfall thresholds, one for each critical level considered, to be used for issue the alert bulletin. Wetness indexes, representative of the soil moisture conditions of a catchment, are calculated using a simple, spatially-lumped rainfall–streamflow model, based on the SCS-CN method, and on the unit hydrograph approach, that require daily observed and/or predicted rainfall, and temperature data as input. For the calibration of this model daily continuous time series of rainfall, streamflow and air temperature data are used. An event based lumped rainfall–runoff model has been, instead, used for the derivation of the rainfall thresholds for each catchment in Sicily characterised by an area larger than 50 km2. In particular, a Kinematic Instantaneous Unit Hydrograph based lumped rainfall–runoff model with the SCS-CN routine for net rainfall was developed for this purpose. For rainfall-induced shallow landslide warning, empirical rainfall thresholds provided by Gariano et al. (2015 have been included in the system. They were derived on an empirical basis starting from a catalogue of 265 shallow landslides in Sicily in the period 2002–2012. Finally, Delft-FEWS operational forecasting platform has been applied to link input data, SMA model and rainfall

  4. Statistical geological discrete fracture network model. Forsmark modelling stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Aaron; La Pointe, Paul [Golder Associates Inc (United States); Simeonov, Assen [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hermanson, Jan; Oehman, Johan [Golder Associates AB, Stockholm (Sweden)

    2007-11-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is performing site characterization at two different locations, Forsmark and Laxemar, in order to locate a site for a final geologic repository for spent nuclear fuel. The program is built upon the development of Site Descriptive Models (SDMs) at specific timed data freezes. Each SDM is formed from discipline-specific reports from across the scientific spectrum. This report describes the methods, analyses, and conclusions of the geological modeling team with respect to a geological and statistical model of fractures and minor deformation zones (henceforth referred to as the geological DFN), version 2.2, at the Forsmark site. The geological DFN builds upon the work of other geological modelers, including the deformation zone (DZ), rock domain (RD), and fracture domain (FD) models. The geological DFN is a statistical model for stochastically simulating rock fractures and minor deformation zones as a scale of less than 1,000 m (the lower cut-off of the DZ models). The geological DFN is valid within four specific fracture domains inside the local model region, and encompassing the candidate volume at Forsmark: FFM01, FFM02, FFM03, and FFM06. The models are build using data from detailed surface outcrop maps and the cored borehole record at Forsmark. The conceptual model for the Forsmark 2.2 geological revolves around the concept of orientation sets; for each fracture domain, other model parameters such as size and intensity are tied to the orientation sets. Two classes of orientation sets were described; Global sets, which are encountered everywhere in the model region, and Local sets, which represent highly localized stress environments. Orientation sets were described in terms of their general cardinal direction (NE, NW, etc). Two alternatives are presented for fracture size modeling: - the tectonic continuum approach (TCM, TCMF) described by coupled size-intensity scaling following power law distributions

  5. The Commercial Bank Credit Risk Conduction Model and Correlation Study on the Early Warning Mechanism under the New Normal%新常态下商业银行信用风险传导模式与关联预警机制研究

    Institute of Scientific and Technical Information of China (English)

    孙勇军

    2016-01-01

    Closely related to the main business indicators of commercial bank asset quality and proift growth, especially in the period of economic downturn, the asset quality is the priority among priorities of commercial bank management. The potential risk of effective early warning and identiifcation is the key to ensure the stable quality of assets. The main early warning mechanism mainly adopts the bottom-up model, many early warning according to their own information, there is room for improvement. This paper aims to reveal the diffusion model and pathway of credit risk, explore "risk for a single customer exposure" for "more customer risk warning signal recognition, asset quality risk management and early warning work to develop new ideas.%商业银行的资产质量与利润增长等主要经营指标密切相关,尤其在经济下行期,资产质量更是商业银行管理的重中之重。有效预警与识别潜在风险是确保资产质量稳定的关键环节。主流预警机制主要采用自下而上模式,多根据企业自身信息进行预警,存在改善空间。本文旨在通过揭示信用风险的扩散模式和传导途径,探索将“单个客户风险暴露”识别为“更多客户的风险预警信号”,为资产质量管理和风险预警工作开拓新的思路。

  6. Targeted labeling of an early-stage tumor spheroid in a chorioallantoic membrane model with upconversion nanoparticles

    NARCIS (Netherlands)

    K. Liu; J.A. Holz; Y. Ding; X. Liu; Y. Zhang; L. Tu; X. Kong; B. Priem; A. Nadort; S.A.G. Lambrechts; M.C.G. Aalders; W.J. Buma; Y. Liu; H. Zhang

    2015-01-01

    In vivo detection of cancer at an early-stage, i.e. smaller than 2 mm, is a challenge in biomedicine. In this work target labeling of an early-stage tumor spheroid (similar to 500 mu m) is realized for the first time in a chick embryo chorioallantoic membrane (CAM) model with monoclonal antibody fun

  7. Chemical analysis of simulated high level waste glasses to support stage III sulfate solubility modeling

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-17

    The U.S. Department of Energy (DOE), Office of Environmental Management (EM) is sponsoring an international, collaborative project to develop a fundamental model for sulfate solubility in nuclear waste glass. The solubility of sulfate has a significant impact on the achievable waste loading for nuclear waste forms within the DOE complex. These wastes can contain relatively high concentrations of sulfate, which has low solubility in borosilicate glass. This is a significant issue for low-activity waste (LAW) glass and is projected to have a major impact on the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Sulfate solubility has also been a limiting factor for recent high level waste (HLW) sludge processed at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). The low solubility of sulfate in glass, along with melter and off-gas corrosion constraints, dictate that the waste be blended with lower sulfate concentration waste sources or washed to remove sulfate prior to vitrification. The development of enhanced borosilicate glass compositions with improved sulfate solubility will allow for higher waste loadings and accelerate mission completion.The objective of the current scope being pursued by SHU is to mature the sulfate solubility model to the point where it can be used to guide glass composition development for DWPF and WTP, allowing for enhanced waste loadings and waste throughput at these facilities. A series of targeted glass compositions was selected to resolve data gaps in the model and is identified as Stage III. SHU fabricated these glasses and sent samples to SRNL for chemical composition analysis. SHU will use the resulting data to enhance the sulfate solubility model and resolve any deficiencies. In this report, SRNL provides chemical analyses for the Stage III, simulated HLW glasses fabricated by SHU in support of the sulfate solubility model development.

  8. Perfect timing: urgency, not driving situations, influence the best timing to activate warnings.

    Science.gov (United States)

    Werneke, Julia; Kleen, Andro; Vollrath, Mark

    2014-03-01

    The aim of the study was to investigate the influence of different driving scenarios (urban, rural, highway) on the timing required by drivers from a two-stage warning system, based on car-to-car communication. Car-to-car communication systems are designed to inform drivers of potential hazards at an early stage, before they are visible to them. Here, questions arise as to how drivers acknowledge early warnings and when they should be informed (first stage) and warned (second stage). Hence, optimum timing for presenting the information was tested. A psychophysical method was used to establish the optimum timing in three driving scenarios at different speed limits (urban: 50 km/h, rural: 100 km/h, highway: 130 km/h). A total of 24 participants (11 female, 13 male; M = 29.1 years, SD = 11.6 years) participated in the study. The results showed that the optimum timing did not differ among the three scenarios.The first and second stages should ultimately be presented at different timings at each speed limit (first stage: 26.5 s, second stage: 12.1 s before a potential hazard). The results showed that well-selected timing for activating information and warning is crucial for the acceptance of these systems. Appropriate timing for presenting the information and warning can be derived for these systems. The findings will be integrated in further development of assistance systems based on car-to-x technology within the Car2X-Safety project of the Niedersächsisches Forschungszentrum Fahrzeugtechnik in Germany.This study was also supported by Chalmers University of Technology in Sweden.

  9. Validated Competing Event Model for the Stage I-II Endometrial Cancer Population

    Energy Technology Data Exchange (ETDEWEB)

    Carmona, Ruben; Gulaya, Sachin; Murphy, James D. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Rose, Brent S. [Harvard Radiation Oncology Program, Harvard Medical School, Boston, Massachusetts (United States); Wu, John; Noticewala, Sonal [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); McHale, Michael T. [Department of Reproductive Medicine, Division of Gynecologic Oncology, University of California San Diego, La Jolla, California (United States); Yashar, Catheryn M. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Vaida, Florin [Department of Family and Preventive Medicine, Biostatistics and Bioinformatics, University of California San Diego Medical Center, San Diego, California (United States); Mell, Loren K., E-mail: lmell@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States)

    2014-07-15

    Purpose/Objectives(s): Early-stage endometrial cancer patients are at higher risk of noncancer mortality than of cancer mortality. Competing event models incorporating comorbidity could help identify women most likely to benefit from treatment intensification. Methods and Materials: 67,397 women with stage I-II endometrioid adenocarcinoma after total hysterectomy diagnosed from 1988 to 2009 were identified in Surveillance, Epidemiology, and End Results (SEER) and linked SEER-Medicare databases. Using demographic and clinical information, including comorbidity, we sought to develop and validate a risk score to predict the incidence of competing mortality. Results: In the validation cohort, increasing competing mortality risk score was associated with increased risk of noncancer mortality (subdistribution hazard ratio [SDHR], 1.92; 95% confidence interval [CI], 1.60-2.30) and decreased risk of endometrial cancer mortality (SDHR, 0.61; 95% CI, 0.55-0.78). Controlling for other variables, Charlson Comorbidity Index (CCI) = 1 (SDHR, 1.62; 95% CI, 1.45-1.82) and CCI >1 (SDHR, 3.31; 95% CI, 2.74-4.01) were associated with increased risk of noncancer mortality. The 10-year cumulative incidences of competing mortality within low-, medium-, and high-risk strata were 27.3% (95% CI, 25.2%-29.4%), 34.6% (95% CI, 32.5%-36.7%), and 50.3% (95% CI, 48.2%-52.6%), respectively. With increasing competing mortality risk score, we observed a significant decline in omega (ω), indicating a diminishing likelihood of benefit from treatment intensification. Conclusion: Comorbidity and other factors influence the risk of competing mortality among patients with early-stage endometrial cancer. Competing event models could improve our ability to identify patients likely to benefit from treatment intensification.

  10. 基于人群搜索算法的上市公司的 Z-Score 模型财务预警研究%The Z-Score Model Financial Early Warning for Listed Companies Based on Seeker Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    赵海蕾; 周方召; 金德环

    2015-01-01

    针对传统的 Z-Score 财务预警模型预警能力的不足,导致无法准确判定上市公司的财务风险状况,将 SOA 算法的良好寻优能力和 Z-Score 财务预警模型结合起来,提出一种改进的 Z-Score 财务预警模型,构建出 SOA 算法优化 Z-Score 财务预警模型的适应度函数。仿真对比发现,改进的 Z-Score 财务预警模型其平均识别率高达96.33%,远远高于 SVM 算法和 AdaBoost 算法的平均识别率,改进的算法极大地提升了 Z-Score 财务预警模型的预测能力,使其更具适应性。%The conventional Z-Score model financial early warning lacks predicative power, making it impossible to accurately determine the financial risk profile of listed companies.It needs to be further optimized to enhance its power.This article combines the optimization ability of SOA with Z-Score financial early warning model algorithms,and proposes an improved Z-Score financial early warning model to construct a SOA algorithm optimization fitness function for the new early warning model.Our simulation result show that the improved Z-Score financial early warning model increases the average recognition rate up to 96.33%,much higher than the aver-age recognition rate of SVM algorithm and AdaBoost algorithm;and the improved algorithm greatly enhances the ability of the Z-Score Financial Early Warning Model by making it more a-daptable.

  11. A tri-stage cluster identification model for accurate analysis of seismic catalogs

    Directory of Open Access Journals (Sweden)

    S. J. Nanda

    2013-02-01

    Full Text Available In this paper we propose a tri-stage cluster identification model that is a combination of a simple single iteration distance algorithm and an iterative K-means algorithm. In this study of earthquake seismicity, the model considers event location, time and magnitude information from earthquake catalog data to efficiently classify events as either background or mainshock and aftershock sequences. Tests on a synthetic seismicity catalog demonstrate the efficiency of the proposed model in terms of accuracy percentage (94.81% for background and 89.46% for aftershocks. The close agreement between lambda and cumulative plots for the ideal synthetic catalog and that generated by the proposed model also supports the accuracy of the proposed technique. There is flexibility in the model design to allow for proper selection of location and magnitude ranges, depending upon the nature of the mainshocks present in the catalog. The effectiveness of the proposed model also is evaluated by the classification of events in three historic catalogs: California, Japan and Indonesia. As expected, for both synthetic and historic catalog analysis it is observed that the density of events classified as background is almost uniform throughout the region, whereas the density of aftershock events are higher near the mainshocks.

  12. Predictive Modeling of a Two-Stage Gearbox towards Fault Detection

    Directory of Open Access Journals (Sweden)

    Edward J. Diehl

    2016-01-01

    Full Text Available This paper presents a systematic approach to the modeling and analysis of a benchmark two-stage gearbox test bed to characterize gear fault signatures when processed with harmonic wavelet transform (HWT analysis. The eventual goal of condition monitoring is to be able to interpret vibration signals from nonstationary machinery in order to identify the type and severity of gear damage. To advance towards this goal, a lumped-parameter model that can be analyzed efficiently is developed which characterizes the gearbox vibratory response at the system level. The model parameters are identified through correlated numerical and experimental investigations. The model fidelity is validated first by spectrum analysis, using constant speed experimental data, and secondly by HWT analysis, using nonstationary experimental data. Model prediction and experimental data are compared for healthy gear operation and a seeded fault gear with a missing tooth. The comparison confirms that both the frequency content and the predicted, relative response magnitudes match with physical measurements. The research demonstrates that the modeling method in combination with the HWT data analysis has the potential for facilitating successful fault detection and diagnosis for gearbox systems.

  13. Two-Stage Single-Compartment Models to Evaluate Dissolution in the Lower Intestine.

    Science.gov (United States)

    Markopoulos, Constantinos; Vertzoni, Maria; Symillides, Mira; Kesisoglou, Filippos; Reppas, Christos

    2015-09-01

    The purpose was to propose two-stage single-compartment models for evaluating dissolution characteristics in distal ileum and ascending colon, under conditions simulating the bioavailability and bioequivalence studies in fasted and fed state by using the mini-paddle and the compendial flow-through apparatus (closed-loop mode). Immediate release products of two highly dosed active pharmaceutical ingredients (APIs), sulfasalazine and L-870,810, and one mesalamine colon targeting product were used for evaluating their usefulness. Change of medium composition simulating the conditions in distal ileum (SIFileum ) to a medium simulating the conditions in ascending colon in fasted state and in fed state was achieved by adding an appropriate solution in SIFileum . Data with immediate release products suggest that dissolution in lower intestine is substantially different than in upper intestine and is affected by regional pH differences > type/intensity of fluid convection > differences in concentration of other luminal components. Asacol® (400 mg/tab) was more sensitive to type/intensity of fluid convection. In all the cases, data were in line with available human data. Two-stage single-compartment models may be useful for the evaluation of dissolution in lower intestine. The impact of type/intensity of fluid convection and viscosity of media on luminal performance of other APIs and drug products requires further exploration.

  14. Two-stage Hidden Markov Model in Gesture Recognition for Human Robot Interaction

    Directory of Open Access Journals (Sweden)

    Nhan Nguyen-Duc-Thanh

    2012-07-01

    Full Text Available Hidden Markov Model (HMM is very rich in mathematical structure and hence can form the theoretical basis for use in a wide range of applications including gesture representation. Most research in this field, however, uses only HMM for recognizing simple gestures, while HMM can definitely be applied for whole gesture meaning recognition. This is very effectively applicable in Human‐Robot Interaction (HRI. In this paper, we introduce an approach for HRI in which not only the human can naturally control the robot by hand gesture, but also the robot can recognize what kind of task it is executing. The main idea behind this method is the 2‐stages Hidden Markov Model. The 1st HMM is to recognize the prime command‐like gestures. Based on the sequence of prime gestures that are recognized from the 1st stage and which represent the whole action, the 2nd HMM plays a role in task recognition. Another contribution of this paper is that we use the output Mixed Gaussian distribution in HMM to improve the recognition rate. In the experiment, we also complete a comparison of the different number of hidden states and mixture components to obtain the optimal one, and compare to other methods to evaluate this performance.

  15. PLASMODIUM PRE-ERYTHROCYTIC STAGES: BIOLOGY, WHOLE PARASITE VACCINES AND TRANSGENIC MODELS

    Directory of Open Access Journals (Sweden)

    Kota Arun Kumar

    2012-01-01

    Full Text Available Malaria remains one of the world’s worst health problems, which causes 216 million new cases and approximately 655,000 deaths every year WHO World Malaria Report, 2011. Malaria transmission to the mammalian host is initiated through a mosquito bite that delivers sporozoites into the vertebrate host. The injected sporozoites are selectively targeted to liver which is the first obligatory step in infection thus making this stage an attractive target for both drug and vaccine development. Research using rodent models of malaria has greatly facilitated the understanding of several aspects of pre-erythrocytic parasite biology and immunology. However, translation of this knowledge to combat Plasmodium falciparum infections still offers several challenges. We highlight in this review some of the recent advances in the field of Plasmodium sporozoite and liver stage biology and in the generation of whole organism attenuated vaccines. We also comment on the application of transgenic models central to Circumsporozoite Protein (CSP in understanding the mechanism of pre-erythrocytic immunity.

  16. Two-Stage Hidden Markov Model in Gesture Recognition for Human Robot Interaction

    Directory of Open Access Journals (Sweden)

    Nhan Nguyen-Duc-Thanh

    2012-07-01

    Full Text Available Hidden Markov Model (HMM is very rich in mathematical structure and hence can form the theoretical basis for use in a wide range of applications including gesture representation. Most research in this field, however, uses only HMM for recognizing simple gestures, while HMM can definitely be applied for whole gesture meaning recognition. This is very effectively applicable in Human-Robot Interaction (HRI. In this paper, we introduce an approach for HRI in which not only the human can naturally control the robot by hand gesture, but also the robot can recognize what kind of task it is executing. The main idea behind this method is the 2-stages Hidden Markov Model. The 1st HMM is to recognize the prime command-like gestures. Based on the sequence of prime gestures that are recognized from the 1st stage and which represent the whole action, the 2nd HMM plays a role in task recognition. Another contribution of this paper is that we use the output Mixed Gaussian distribution in HMM to improve the recognition rate. In the experiment, we also complete a comparison of the different number of hidden states and mixture components to obtain the optimal one, and compare to other methods to evaluate this performance.

  17. Earthquake early warning system using real-time signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Leach, R.R. Jr.; Dowla, F.U.

    1996-02-01

    An earthquake warning system has been developed to provide a time series profile from which vital parameters such as the time until strong shaking begins, the intensity of the shaking, and the duration of the shaking, can be derived. Interaction of different types of ground motion and changes in the elastic properties of geological media throughout the propagation path result in a highly nonlinear function. We use neural networks to model these nonlinearities and develop learning techniques for the analysis of temporal precursors occurring in the emerging earthquake seismic signal. The warning system is designed to analyze the first-arrival from the three components of an earthquake signal and instantaneously provide a profile of impending ground motion, in as little as 0.3 sec after first ground motion is felt at the sensors. For each new data sample, at a rate of 25 samples per second, the complete profile of the earthquake is updated. The profile consists of a magnitude-related estimate as well as an estimate of the envelope of the complete earthquake signal. The envelope provides estimates of damage parameters, such as time until peak ground acceleration (PGA) and duration. The neural network based system is trained using seismogram data from more than 400 earthquakes recorded in southern California. The system has been implemented in hardware using silicon accelerometers and a standard microprocessor. The proposed warning units can be used for site-specific applications, distributed networks, or to enhance existing distributed networks. By producing accurate, and informative warnings, the system has the potential to significantly minimize the hazards of catastrophic ground motion. Detailed system design and performance issues, including error measurement in a simple warning scenario are discussed in detail.

  18. Neural network strategies for issuing flood warning alerts

    Science.gov (United States)

    Abrahart, R.; Dawson, C.; See, L.; Wilby, R.

    2003-04-01

    Most neural network hydrological forecasting involves modelling standard combinations of traditional rainfall-runoff variables in a supervised learning environment. These computational solutions have to date produced reasonable approximations but various problems still exist in the manner of input and output data inadequacies and weak deterministic hydrological relationships. The supervised learning model also puts an arduous burden on the instructor mechanism which requires a comprehensive set of meaningful real-world input-output situations. It is argued that the information content on either side of the equation must be modified if such tools are to achieve improved performance and that alternative relationships might be used to build superior modelling solutions e.g. to predict Fourier Series Parameters instead of Measured Hydrological Variables. This paper thus compares alternative strategies that can be used to deliver neural network flood warning alerts based on a six-hour forecasting horizon for the River Ouse in Yorkshire - a river that experiences major floods. The first solution uses a standard neural network modelling procedure to predict river level outputs which are then classified into four flood alert codes: ALL CLEAR; FLOOD WATCH; FLOOD WARNING; SEVERE FLOOD WARNING. The other solutions use identical data inputs to predict a simpler output function that is easier to learn; comprising the four individual event codes modelled as a set of categorical entities. The non-standard approaches that are considered consist of: [i] single-winner, [ii] thermometer method and [iii] a self-organising map.

  19. Information systems in a changing climate: Early warnings and drought risk management

    Directory of Open Access Journals (Sweden)

    Roger S. Pulwarty

    2014-06-01

    Full Text Available Drought is among the most damaging, and least understood, of all “natural” hazards. Although some droughts last a single season and affect only small areas, the instrumental and paleoclimate records show that droughts have sometimes continued for decades and have impacted millions of square kilometers in North America, West Africa, and East Asia. To cross the spectrum of potential drivers and impacts, drought information systems have multiple sub-systems which include an integrated risk assessment, communication and decision support system of which early warning is a central component and output. An early warning system is much more than a forecast – it is a linked risk information (including people׳s perception of risk and communication system that actively engages communities involved in preparedness. There are numerous drought systems warning systems being implemented at different scales of governance. We draw on the lessons of over 21 drought early warning systems around the world, in both developing and developed countries and at regional, national and community levels. The successes illustrate that effective early warning depends upon a multi-sectoral and interdisciplinary collaboration among all concerned actors at each stage in the warning process from monitoring to response and evaluation. However, the links between the community-based approach and the national and global EWSs are relatively weak. Using the rich experience of information systems across the globe, this paper identifies pathways for knowledge management and action at the relevant scales for decision-making in response to a changing climate.

  20. Study on the early warning mechanism for the security of blast furnace hearths

    Science.gov (United States)

    Zhao, Hong-bo; Huo, Shou-feng; Cheng, Shu-sen

    2013-04-01

    The campaign life of blast furnace (BF) hearths has become the limiting factor for safety and high efficiency production of modern BFs. However, the early warning mechanism of hearth security has not been clear. In this article, based on heat transfer calculations, heat flux and erosion monitoring, the features of heat flux and erosion were analyzed and compared among different types of hearths. The primary detecting elements, mathematical models, evaluating standards, and warning methods were discussed. A novel early warning mechanism with the three-level quantificational standards was proposed for BF hearth security.

  1. THE IMPLEMENTATION OF THE 5E MODEL STAGES TO BUILD STUDENTS’ VOCABULARY

    Directory of Open Access Journals (Sweden)

    Muhammad Rochman

    2015-12-01

    Full Text Available There are stages of human to learn something. In early ages, they will learn simplest things to the complicated ones. A learning process of human is started with and introductory and it tries to connect with their prior knowledge to the new one. Children begin to curious about what they want to know and start to make some questions about what they want to know. In the process of finding the answers of their own questions, they will interact with others and try to share the knowledge in this process. The result of this study illustrates that the implementation of the 5E model in teaching vocabulary that can enhance the students’ vocabulary achievement and successfully encourages them to actively and enthusiastically take part in the teaching-learning process of vocabulary through group task. Keywords: implementation, vocabulary, vocabulary course, and 5E model

  2. Performance Testing of the Engineering Model Astro-H 3-stage ADR

    Science.gov (United States)

    Shirron, Peter J.; Kimball, Mark O.; DiPirro, Michael J.

    2013-01-01

    The Japanese Astro-H mission will include the Soft X-ray Spectrometer (SXS) instrument provided by NASA/GSFC. The SXS will perform imaging spectroscopy in the soft x-ray band using a 6x6 array of silicon microcalorimeters operated at 50 mK. The detectors are cooled by a 3-stage adiabatic demagnetization refrigerator (ADR), which is configured to use either a 1.3 K superfluid helium tank or a 4.5 K Joule-Thomson cryocooler as a heat sink. At present, the engineering model SXS, including the detectors and ADR, has been performance tested at GSFC and integrated with the EM dewar in Japan. The flight model SXS is currently being fabricated. This paper presents test results of the EM ADR and changes that will be implemented in the flight version.

  3. A three-stage colonization model for the peopling of the Americas.

    Directory of Open Access Journals (Sweden)

    Andrew Kitchen

    Full Text Available BACKGROUND: We evaluate the process by which the Americas were originally colonized and propose a three-stage model that integrates current genetic, archaeological, geological, and paleoecological data. Specifically, we analyze mitochondrial and nuclear genetic data by using complementary coalescent models of demographic history and incorporating non-genetic data to enhance the anthropological relevance of the analysis. METHODOLOGY/FINDINGS: Bayesian skyline plots, which provide dynamic representations of population size changes over time, indicate that Amerinds went through two stages of growth approximately 40,000 and approximately 15,000 years ago separated by a long period of population stability. Isolation-with-migration coalescent analyses, which utilize data from sister populations to estimate a divergence date and founder population sizes, suggest an Amerind population expansion starting approximately 15,000 years ago. CONCLUSIONS/SIGNIFICANCE: These results support a model for the peopling of the New World in which Amerind ancestors diverged from the Asian gene pool prior to 40,000 years ago and experienced a gradual population expansion as they moved into Beringia. After a long period of little change in population size in greater Beringia, Amerinds rapidly expanded into the Americas approximately 15,000 years ago either through an interior ice-free corridor or along the coast. This rapid colonization of the New World was achieved by a founder group with an effective population size of approximately 1,000-5,400 individuals. Our model presents a detailed scenario for the timing and scale of the initial migration to the Americas, substantially refines the estimate of New World founders, and provides a unified theory for testing with future datasets and analytic methods.

  4. [Quantitative models between canopy hyperspectrum and its component features at apple tree prosperous fruit stage].

    Science.gov (United States)

    Wang, Ling; Zhao, Geng-xing; Zhu, Xi-cun; Lei, Tong; Dong, Fang

    2010-10-01

    Hyperspectral technique has become the basis of quantitative remote sensing. Hyperspectrum of apple tree canopy at prosperous fruit stage consists of the complex information of fruits, leaves, stocks, soil and reflecting films, which was mostly affected by component features of canopy at this stage. First, the hyperspectrum of 18 sample apple trees with reflecting films was compared with that of 44 trees without reflecting films. It could be seen that the impact of reflecting films on reflectance was obvious, so the sample trees with ground reflecting films should be separated to analyze from those without ground films. Secondly, nine indexes of canopy components were built based on classified digital photos of 44 apple trees without ground films. Thirdly, the correlation between the nine indexes and canopy reflectance including some kinds of conversion data was analyzed. The results showed that the correlation between reflectance and the ratio of fruit to leaf was the best, among which the max coefficient reached 0.815, and the correlation between reflectance and the ratio of leaf was a little better than that between reflectance and the density of fruit. Then models of correlation analysis, linear regression, BP neural network and support vector regression were taken to explain the quantitative relationship between the hyperspectral reflectance and the ratio of fruit to leaf with the softwares of DPS and LIBSVM. It was feasible that all of the four models in 611-680 nm characteristic band are feasible to be used to predict, while the model accuracy of BP neural network and support vector regression was better than one-variable linear regression and multi-variable regression, and the accuracy of support vector regression model was the best. This study will be served as a reliable theoretical reference for the yield estimation of apples based on remote sensing data.

  5. Safe distance model and obstacle detection algorithms for a collision warning and collision avoidance system%汽车主动避撞系统的安全距离模型和目标检测算法

    Institute of Scientific and Technical Information of China (English)

    裴晓飞; 刘昭度; 马国成; 叶阳

    2012-01-01

    为辅助汽车驾驶员安全驾驶,开发了一种汽车主动避撞系统。该系统以"碰撞时间倒数"TTC-1作为评价指标,采用了基于危险系数ε进行分级报警与主动制动的安全距离模型,其关键参数按照驾驶员特性进行标定。基于自适应巡航系统(ACC)目标检测算法,设计了适用于避撞系统的毫米波雷达算法。基于捷达轿车,开发了用于避撞系统的软硬件平台,并在良好路面下分别进行了主动避撞试验和人为切换试验。实车试验表明:本系统的分级报警和主动制动功能,符合期望的TTC-1指标,提高了汽车的主动安全性,体现了驾驶员控制的优先性和协调性。%Safe-driving was assisted with key parameters calibrated according to the driver’s characteristics using a developed system of vehicle collision warning and collision avoidance (CW/CA). The system defines the inverse of time-to-collision (TTC-1) as the evaluation index with the grading warning and braking safe distance model adopted based on hazardous level ε. A millimeter waveradar obstacle detection method was designed with adaptive cruise control (ACC). The system configuration and control logic were designed based on a Jetta car with the collision avoidance test and the manual / automatic interaction test implemented on dry roads. The real car experiments show that the CW/CA system in accordance with desired TTC-1 index improves vehicle active safety, and embodies the driver’s priority and cooperation.

  6. Dynamic modeling of a single-stage downward firing, entrained flow gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Kasule, J., Turton, R., Bhattacharyya, D., Zitney, S.

    2012-01-01

    The gasifier is the heart of the integrated gasification combined cycle (IGCC), a technology that has emerged as an attractive alternative to conventional coal-fired power plant technology due to its higher efficiency and cleaner environmental performance especially with the option of CO{sub 2} capture and sequestration. Understanding the optimal performance of the gasifier is therefore paramount for the efficient operation of IGCC power plants. Numerous gasifier models of varying complexity have been developed to study the various aspects of gasifier performance. These range from simple one-dimensional (1D) process-type models to rigorous higher order 2-3D models based on computational fluid dynamics (CFD). Whereas high-fidelity CFD models can accurately predict most key aspects of gasifier performance, they are computationally expensive and typically take hours to days to execute on high-performance computers. Therefore, faster 1D partial differential equation (PDE)-based models are required for use in dynamic simulation studies, control system analysis, and training applications. A number of 1D gasifier models can be found in the literature, but most are steady-state models that have limited application in the practical operation of the gasifier. As a result, 1D PDE-based dynamic models are needed to further study and predict gasifier performance under a wide variety of process conditions and disturbances. In the current study, a 1D transient model of a single-stage downward-fired GE/Texaco-type entrained-flow gasifier has been developed. The model comprises mass, momentum and energy balances for the gas and solid phases. The model considers the initial gasification processes of water evaporation and coal devolatilization. In addition, the key heterogeneous and homogeneous chemical reactions have been modeled. The resulting time-dependent PDE model is solved using the well-known method of lines approach in Aspen Custom Modeler®, whereby the PDEs in the spatial

  7. Investigating mathematical models of immuno-interactions with early-stage cancer under an agent-based modelling perspective

    Science.gov (United States)

    2013-01-01

    Many advances in research regarding immuno-interactions with cancer were developed with the help of ordinary differential equation (ODE) models. These models, however, are not effectively capable of representing problems involving individual localisation, memory and emerging properties, which are common characteristics of cells and molecules of the immune system. Agent-based modelling and simulation is an alternative paradigm to ODE models that overcomes these limitations. In this paper we investigate the potential contribution of agent-based modelling and simulation when compared to ODE modelling and simulation. We seek answers to the following questions: Is it possible to obtain an equivalent agent-based model from the ODE formulation? Do the outcomes differ? Are there any benefits of using one method compared to the other? To answer these questions, we have considered three case studies using established mathematical models of immune interactions with early-stage cancer. These case studies were re-conceptualised under an agent-based perspective and the simulation results were then compared with those from the ODE models. Our results show that it is possible to obtain equivalent agent-based models (i.e. implementing the same mechanisms); the simulation output of both types of models however might differ depending on the attributes of the system to be modelled. In some cases, additional insight from using agent-based modelling was obtained. Overall, we can confirm that agent-based modelling is a useful addition to the tool set of immunologists, as it has extra features that allow for simulations with characteristics that are closer to the biological phenomena. PMID:23734575

  8. Determination of early warning signs for photocatalytic degradation of titanium white oil paints by means of surface analysis

    Science.gov (United States)

    van Driel, B. A.; Wezendonk, T. A.; van den Berg, K. J.; Kooyman, P. J.; Gascon, J.; Dik, J.

    2017-02-01

    Titanium white (TiO2) has been widely used as a pigment in the 20th century. However, its most photocatalytic form (anatase) can cause severe degradation of the oil paint in which it is contained. UV light initiates TiO2-photocatalyzed processes in the paint film, degrading the oil binder into volatile components resulting in chalking of the paint. This will eventually lead to severe changes in the appearance of a painting. To date, limited examples of degraded works of art containing titanium white are known due to the relatively short existence of the paintings in question and the slow progress of the degradation process. However, UV light will inevitably cause degradation of paint in works of art containing photocatalytic titanium white. In this work, a method to detect early warning signs of photocatalytic degradation of unvarnished oil paint is proposed, using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Consequently, a four-stage degradation model was developed through in-depth study of TiO2-containing paint films in various stages of degradation. The XPS surface analysis proved very valuable for detecting early warning signs of paint degradation, whereas the AFM results provide additional confirmation and are in good agreement with bulk gloss reduction.

  9. Lab-testing, predicting, and modeling multi-stage activated carbon adsorption of organic micro-pollutants from treated wastewater.

    Science.gov (United States)

    Zietzschmann, F; Altmann, J; Hannemann, C; Jekel, M

    2015-10-15

    Multi-stage reuse of powdered activated carbon (PAC) is often applied in practice for a more efficient exploitation of the PAC capacity to remove organic micro-pollutants (OMP). However, the adsorption mechanisms in multi-stage PAC reuse are rarely investigated, as large-scale experiments do not allow for systematic tests. In this study, a laboratory method for the separation of PAC/water suspensions and the subsequent reuse of the PAC and the water was developed. The method was tested on wastewater treatment plant (WWTP) effluent in a setup with up to 7 PAC reuse stages. The tests show that the overall OMP removal from WWTP effluent can be increased when reusing PAC. The reason is that a repeated adsorption in multi-stage PAC reuse results in similar equilibrium concentrations as a single-stage adsorption. Thus, a single relationship between solid and liquid phase OMP concentrations appears valid throughout all stages. This also means that the adsorption efficiency of multi-stage PAC reuse setups can be estimated from the data of a single-stage setup. Furthermore, the overall OMP removals in multi-stage setups coincide with the overall UV254 removals, and for each respective OMP one relationship to UV254 removal is valid throughout all stages. The results were modeled by a simple modification of the equivalent background compound model (EBCM) which was also used to simulate the additional OMP removals in multi-stage setups with up to 50 reuse stages. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Modelos de alerta para o controle da ferrugem-do-cafeeiro em lavouras com alta carga pendente Warning models for coffee rust control in growing areas with large fruit load

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Alves Meira

    2009-03-01

    Full Text Available O objetivo deste trabalho foi desenvolver árvores de decisão como modelos de alerta da ferrugem-do-cafeeiro em lavouras de café (Coffea arabica L. com alta carga pendente de frutos. Dados de incidência mensal da doença no campo coletados durante oito anos foram transformados em valores binários considerando limites de 5 e 10 pontos percentuais na taxa de infecção. Foi gerado um modelo para cada taxa de infecção binária a partir de dados meteorológicos e do espaçamento entre plantas. O alerta é indicado quando a taxa de infecção, prevista para o prazo de um mês, atingir ou ultrapassar o respectivo limite. A acurácia do modelo para o limite de 5 pontos percentuais foi de 81%, por validação cruzada, chegando até 89% segundo estimativa otimista. Esse modelo apresentou bons resultados para outras medidas de avaliação importantes, como sensitividade (80%, especificidade (83% e confiabilidades positiva (79% e negativa (84%. O modelo para o limite de 10 pontos percentuais teve acurácia de 79%, e não apresentou o mesmo equilíbrio entre as demais medidas. Em conjunto, esses modelos podem auxiliar na tomada de decisão referente ao controle da ferrugem-do-cafeeiro no campo. A indução de árvores de decisão é alternativa viável às técnicas convencionais de modelagem e facilita a compreensão dos modelos.The objective of this work was to develop decision trees as warning models of coffee (Coffea arabica L. rust in growing areas with large fruit load. Monthly data of disease incidence in the field collected during eight years were transformed into binary values considering limits of 5 and 10 percentage points in the infection rate. Models were generated from meteorological data and space between plants for each binary infection rate. The warning is indicated when the infection rate is expected to reach or exceed the respective limit in a month. The accuracy obtained by cross-validating the model to the limit of 5 percentage

  11. Flexible distributions for triple-goal estimates in two-stage hierarchical models

    Science.gov (United States)

    Paddock, Susan M.; Ridgeway, Greg; Lin, Rongheng; Louis, Thomas A.

    2009-01-01

    Performance evaluations often aim to achieve goals such as obtaining estimates of unit-specific means, ranks, and the distribution of unit-specific parameters. The Bayesian approach provides a powerful way to structure models for achieving these goals. While no single estimate can be optimal for achieving all three inferential goals, the communication and credibility of results will be enhanced by reporting a single estimate that performs well for all three. Triple goal estimates [Shen and Louis, 1998. Triple-goal estimates in two-stage hierarchical models. J. Roy. Statist. Soc. Ser. B 60, 455–471] have this performance and are appealing for performance evaluations. Because triple-goal estimates rely more heavily on the entire distribution than do posterior means, they are more sensitive to misspecification of the population distribution and we present various strategies to robustify triple-goal estimates by using nonparametric distributions. We evaluate performance based on the correctness and efficiency of the robustified estimates under several scenarios and compare empirical Bayes and fully Bayesian approaches to model the population distribution. We find that when data are quite informative, conclusions are robust to model misspecification. However, with less information in the data, conclusions can be quite sensitive to the choice of population distribution. Generally, use of a nonparametric distribution pays very little in efficiency when a parametric population distribution is valid, but successfully protects against model misspecification. PMID:19603088

  12. Integration of Life-Stage Physiologically Based Pharmacokinetic Models with Adverse Outcome Pathways and Environmental Exposure Models to Screen for Environmental Hazards

    Science.gov (United States)

    A Life-stage Physiologically-Based Pharmacokinetic (PBPK) model was developed to include descriptions of several life-stage events such as pregnancy, fetal development, the neonate and child growth. The overall modeling strategy was used for in vitro to in vivo (IVIVE) extrapolat...

  13. Vehicle Dynamics Approach to Driver Warning

    Directory of Open Access Journals (Sweden)

    Youssef A. Ghoneim

    2013-01-01

    Full Text Available This paper discusses a concept for enhanced active safety by introducing a driver warning system based on vehicle dynamics that predicts a potential loss of control condition prior to stability control activation. This real-time warning algorithm builds on available technologies such as the Electronic Stability Control (ESC. The driver warning system computes several indices based on yaw rate, side-slip velocity, and vehicle understeer using ESC sensor suite. An arbitrator block arbitrates between the different indices and determines the status index of the driving vehicle. The status index is compared to predetermined stability levels which correspond to high and low stability levels. If the index exceeds the high stability level, a warning signal (haptic, acoustic, or visual is issued to alert the driver of a potential loss of control and ESC activation. This alert will remain in effect until the index is less than the low stability level at which time the warning signal will be terminated. A vehicle speed advisory algorithm is integrated with the warning algorithm to provide a desired vehicle speed of a vehicle traveling on a curve. Simulation results and vehicle tests were conducted to illustrate the effectiveness of the warning algorithm.

  14. Measuring the adoption of consistent use of condoms using the stages of change model. AIDS Community Demonstration Projects.

    Science.gov (United States)

    Schnell, D J; Galavotti, C; Fishbein, M; Chan, D K

    1996-01-01

    The stages of behavior change model has been used to understand a variety of health behaviors. Since consistent condom use has been promoted as a risk-reduction behavior for prevention of human immunodeficiency virus (HIV) infection, an algorithm for staging the adoption of consistent condom use during vaginal sex was empirically developed using three considerations: HIV prevention efficacy, analogy with work on staging other health-related behaviors, and condom use data from groups at high risk for HIV infection. This algorithm suggests that the adoption of consistent condom use among persons at high risk can be meaningfully measured with the model. However, variations in the algorithm details affect both the interpretation of stages and apportionment of persons across stages.

  15. Connecting earthquake source products to local tsunami warning

    Science.gov (United States)

    Melgar, D.; Allen, R. M.

    2015-12-01

    Issuing warning of a tsunami in advance of its arrival to the coastlines immediately adjacent to large earthquakes remains a challenging problem. The heterogeneous development state of regional geophysical monitoring infrastructure across subduction zones worldwide means that a flexible approach to warning, capable of ingesting multiple data types and earthquake source products, is the most appealing. We will present results from the study of 3 recent large events that have been observed with diverse geophysical measurements; the 2011 Mw9.0 Tohoku-oki, the 2010 Mw8.8 Maule and 2014 Mw8.2 Iquique events. First, we will show that earthquake slip models derived from combination of land (GPS and strong motion) as well as off-shore (tide gauges, ocean-bottom pressure, and GPS buoy) can be coupled to tsunami propagation models to produce simulations that closely match the measured run-up at the local coastlines. Using these models as a baseline for validation we will demonstrate a methodology that takes advantage of simpler, but more readily available earthquake source products such as rapid point-source magnitude estimates from coastal GPS observations and regional moment tensors. We will show that while trading-off precision for speed, these simpler earthquake source models produce inundation forecasts reliable enough to be used for warning within minutes of earthquake onset. Most subduction zones around the world already have some geophysical infrastructure and are producing some form of real-time earthquake source product, our results strongly argue that by coupling these data products to tsunami propagation models local tsunami warning is possible at most subduction zones with already available infrastructure.

  16. Early warning of orographically induced floods and landslides in Western Norway

    Science.gov (United States)

    Leine, Ann-Live; Wang, Thea; Boje, Søren

    2017-04-01

    In Western Norway, landslides and debris flows are commonly initiated by short-term orographic rainfall or intensity peaks during a prolonged rainfall event. In recent years, the flood warning service in Norway has evolved from being solely a flood forecasting service to also integrating landslides into its early warning systems. As both floods and landslides are closely related to the same hydrometeorological processes, particularly in small catchments, there is a natural synergy between monitoring flood and landslide risk. The Norwegian Flood and Landslide Hazard Forecasting and Warning Service issues regional landslide hazard warnings based on hydrological models, threshold values, observations and weather forecasts. Intense rainfall events and/or orographic precipitation that, under certain topographic conditions, significantly increase the risk of debris avalanches and debris floods are lately receiving more research focus from the Norwegian warning service. Orographic precipitation is a common feature in W-Norway, when moist and relatively mild air arrives from the Atlantic. Steep mountain slopes covered by glacial till makes the region prone to landslides, as well as flooding. The operational early warning system in Norway requires constant improvement, especially with the enhanced number of intense rainfall events that occur in a warming climate. Here, we examine different cases of intense rainfall events which have lead to landslides and debris flows, as well as increased runoff in fast responding small catchments. The main objective is to increase the understanding of the hydrometeorological conditions related to these events, in order to make priorities for the future development of the warning service.

  17. Cable Overheating Risk Warning Method Based on Impedance Parameter Estimation in Distribution Network

    Science.gov (United States)

    Yu, Zhang; Xiaohui, Song; Jianfang, Li; Fei, Gao

    2017-05-01

    Cable overheating will lead to the cable insulation level reducing, speed up the cable insulation aging, even easy to cause short circuit faults. Cable overheating risk identification and warning is nessesary for distribution network operators. Cable overheating risk warning method based on impedance parameter estimation is proposed in the paper to improve the safty and reliability operation of distribution network. Firstly, cable impedance estimation model is established by using least square method based on the data from distribiton SCADA system to improve the impedance parameter estimation accuracy. Secondly, calculate the threshold value of cable impedance based on the historical data and the forecast value of cable impedance based on the forecasting data in future from distribiton SCADA system. Thirdly, establish risks warning rules library of cable overheating, calculate the cable impedance forecast value and analysis the change rate of impedance, and then warn the overheating risk of cable line based on the overheating risk warning rules library according to the variation relationship between impedance and line temperature rise. Overheating risk warning method is simulated in the paper. The simulation results shows that the method can identify the imedance and forecast the temperature rise of cable line in distribution network accurately. The result of overheating risk warning can provide decision basis for operation maintenance and repair.

  18. A Two-Stage Process Model of Sensory Discrimination: An Alternative to Drift-Diffusion.

    Science.gov (United States)

    Sun, Peng; Landy, Michael S

    2016-11-02

    Discrimination of the direction of motion of a noisy stimulus is an example of sensory discrimination under uncertainty. For stimuli that are extended in time, reaction time is quicker for larger signal values (e.g., discrimination of opposite directions of motion compared with neighboring orientations) and larger signal strength (e.g., stimuli with higher contrast or motion coherence, that is, lower noise). The standard model of neural responses (e.g., in lateral intraparietal cortex) and reaction time for discrimination is drift-diffusion. This model makes two clear predictions. (1) The effects of signal strength and value on reaction time should interact multiplicatively because the diffusion process depends on the signal-to-noise ratio. (2) If the diffusion process is interrupted, as in a cued-response task, the time to decision after the cue should be independent of the strength of accumulated sensory evidence. In two experiments with human participants, we show that neither prediction holds. A simple alternative model is developed that is consistent with the results. In this estimate-then-decide model, evidence is accumulated until estimation precision reaches a threshold value. Then, a decision is made with duration that depends on the signal-to-noise ratio achieved by the first stage. Sensory decision-making under uncertainty is usually modeled as the slow accumulation of noisy sensory evidence until a threshold amount of evidence supporting one of the possible decision outcomes is reached. Furthermore, it has been suggested that this accumulation process is reflected in neural responses, e.g., in lateral intraparietal cortex. We derive two behavioral predictions of this model and show that neither prediction holds. We introduce a simple alternative model in which evidence is accumulated until a sufficiently precise estimate of the stimulus is achieved, and then that estimate is used to guide the discrimination decision. This model is consistent with the

  19. Building an Early Warning System for Crude Oil Price Using Neural Network

    Directory of Open Access Journals (Sweden)

    Wonho Song

    2010-12-01

    Full Text Available In this paper, a crisis index for the oil price shock is defined and a neural network model is specified for the prediction of the crisis index. This paper contributes to the literature in three ways. First, we build an early warning system for crude oil price. Although the oil price became one of the most important price index recently, no research efforts have been made to build an early warning system for crude oil price. Second, the neural network (NN model is used to construct the early warning sysIn this paper, a crisis index for the oil price shock is defined and a neural network model is specified for the prediction of the crisis index. This paper contributes to the literature in three ways. First, we build an early warning system for crude oil price. Although the oil price became one of the most important price index recently, no research efforts have been made to build an early warning system for crude oil price. Second, the neural network (NN model is used to construct the early warning system. Most early warning systems are built based on the signaling approach. In this paper, we show that the neural network models are more flexible and have greater potential as EWS than the signaling approach. Third, we allow the multi-level crisis index. Previous models allowed only a zero/one crisis index whereas our model permits as many levels as possible. With this new model, we try to answer whether the oil price collapse following the historical peak in 2008 was predictable. We compare the results from the NN model with those from the ordered probit (OP model, and show that the oil price crisis and the following crash were predictable by the NN model, but not by the OP model.

  20. Birth, growth and progresses through the last twelve years of a regional scale landslide warning system

    Science.gov (United States)

    Fanti, Riccardo; Segoni, Samuele; Rosi, Ascanio; Lagomarsino, Daniela; Catani, Filippo

    2017-04-01

    SIGMA is a regional landslide warning system that operates in the Emilia Romagna region (Italy). In this work, we depict its birth and the continuous development process, still ongoing, after over a decade of operational employ. Traditionally, landslide rainfall thresholds are defined by the empirical correspondence between a rainfall database and a landslide database. However, in the early stages of the research, a complete catalogue of dated landslides was not available. Therefore, the prototypal version of SIGMA was based on rainfall thresholds defined by means of a statistical analysis performed over the rainfall time series. SIGMA was purposely designed to take into account both shallow and deep seated landslides and it was based on the hypothesis that anomalous or extreme values of accumulated rainfall are responsible for landslide triggering. The statistical distribution of the rainfall series was analyzed, and multiples of the standard deviation (σ) were used as thresholds to discriminate between ordinary and extraordinary rainfall events. In the warning system, the measured and the forecasted rainfall are compared with these thresholds. Since the response of slope stability to rainfall may be complex, SIGMA is based on a decision algorithm aimed at identifying short but exceptionally intense rainfalls and mild but exceptionally prolonged rains: while the former are commonly associated with shallow landslides, the latter are mainly associated with deep-seated landslides. In the first case, the rainfall threshold is defined by high σ values and short durations (i.e. a few days); in the second case, σ values are lower but the decision algorithm checks long durations (i.e. some months). The exact definition of "high" and "low" σ values and of "short" and "long" duration varied through time according as it was adjusted during the evolution of the model. Indeed, since 2005, a constant work was carried out to gather and organize newly available data (rainfall

  1. Staging of liver fibrosis in chronic hepatitis B patients with a composite predictive model:A comparative study

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM:To evaluate the efficacy of 6 noninvasive liver fibrosis models and to identify the most valuable model for the prediction of liver fibrosis stage in chronic hepatitis B(CHB) patients.METHODS:Seventy-eight CHB patients were consecutively enrolled in this study.Liver biopsy was performed and blood serum was obtained at admission.Histological diagnosis was made according to the METAVIR system.Significant fibrosis was defined as stage score ≥ 2,severe fibrosis as stage score ≥ 3.The diagnostic accuracy of ...

  2. Modeling polycyclic aromatic hydrocarbon bioaccumulation and metabolism in time-variable early life-stage exposures.

    Science.gov (United States)

    Mathew, Rooni; McGrath, Joy A; Di Toro, Dominic M

    2008-07-01

    Recent laboratory investigations into the bioaccumulation and toxicity of polycyclic aromatic hydrocarbons (PAH) have focused on low-level, time-variable exposures to early life-stage fish. Polycyclic aromatic hydrocarbon body-burden residues reported in these studies were lower than critical body-burden residues predicted by the target lipid model (TLM). To understand this discrepancy, a time-variable uptake and depuration model of PAH bioaccumulation was developed. Kinetic constants were fit using measured exposure and tissue concentrations. The resulting lipid-water partition coefficients (K(LW)) were uncorrelated with the octanol-water partition coefficient (K(OW))--a qualitatively unrealistic finding considering that numerous studies have reported a positive correlation between the two. Because PAHs are known to be metabolized, the comparison of K(LW) with K(OW) suggests that metabolism may be occurring in early life-stage fish. Therefore, the uptake and depuration model was modified to include metabolism while assuming linearity of K(LW) with K(OW). Calculated metabolism rates were positively correlated with K(OW)--a finding qualitatively similar to those of other studies. The present study provides a reasonable explanation for the discrepancy between the TLM predictions and the measured toxic effect levels. Given the time-variable exposure concentrations, the maximum measured body burdens used to relate to toxic effects may be underestimated. In addition, the maximum body burden of parent PAH plus metabolites may be a better measure in relating tissue concentrations to toxic effects. Incorporating these refinements in relating body burdens to toxic effects may result in a better comparison between TLM predictions and measured effect levels.

  3. A discrete stage-structured model of California newt population dynamics during a period of drought.

    Science.gov (United States)

    Jones, Marjorie T; Milligan, William R; Kats, Lee B; Vandergon, Thomas L; Honeycutt, Rodney L; Fisher, Robert N; Davis, Courtney L; Lucas, Timothy A

    2017-02-07

    We introduce a mathematical model for studying the population dynamics under drought of the California newt (Taricha torosa), a species of special concern in the state of California. Since 2012, California has experienced a record-setting drought, and multiple studies predict drought conditions currently underway will persist and even increase in severity. Recent declines and local extinctions of California newt populations in Santa Monica Mountain streams motivate our study of the impact of drought on newt population sizes. Although newts are terrestrial salamanders, they migrate to streams each spring to breed and lay eggs. Since egg and larval stages occur in water, a precipitation deficit due to drought conditions reduces the space for newt egg-laying and the necessary habitat for larval development. To mathematically forecast newt population dynamics, we develop a nonlinear system of discrete equations that includes demographic parameters such as survival rates for newt life stages and egg production, which depend on habitat availability and rainfall. We estimate these demographic parameters using 15 years of stream survey data collected from Cold Creek in Los Angeles County, California, and our model captures the observed decline of the parameterized Cold Creek newt population. Based upon data analysis, we predict how the number of available newt egg-laying sites varies with annual precipitation. Our model allows us to make predictions about how the length and severity of drought can affect the likelihood of persistence and the time to critical endangerment of a local newt population. We predict that sustained severe drought will critically endanger the newt population but that the newt population can rebound if a drought is sufficiently short.

  4. A discrete stage-structured model of California newt population dynamics during a period of drought

    Science.gov (United States)

    Jones, Marjorie T.; Milligan, William R.; Kats, Lee B.; Vandergon, Thomas L.; Honeycutt, Rodney L.; Fisher, Robert N.; Davis, Courtney L.; Lucas, Timothy A.

    2017-01-01

    We introduce a mathematical model for studying the population dynamics under drought of the California newt (Taricha torosa), a species of special concern in the state of California. Since 2012, California has experienced a record-setting drought, and multiple studies predict drought conditions currently underway will persist and even increase in severity. Recent declines and local extinctions of California newt populations in Santa Monica Mountain streams motivate our study of the impact of drought on newt population sizes. Although newts are terrestrial salamanders, they migrate to streams each spring to breed and lay eggs. Since egg and larval stages occur in water, a precipitation deficit due to drought conditions reduces the space for newt egg-laying and the necessary habitat for larval development. To mathematically forecast newt population dynamics, we develop a nonlinear system of discrete equations that includes demographic parameters such as survival rates for newt life stages and egg production, which depend on habitat availability and rainfall. We estimate these demographic parameters using 15 years of stream survey data collected from Cold Creek in Los Angeles County, California, and our model captures the observed decline of the parameterized Cold Creek newt population. Based upon data analysis, we predict how the number of available newt egg-laying sites varies with annual precipitation. Our model allows us to make predictions about how the length and severity of drought can affect the likelihood of persistence and the time to critical endangerment of a local newt population. We predict that sustained severe drought will critically endanger the newt population but that the newt population can rebound if a drought is sufficiently short.

  5. Geological, isothermal, and isobaric 3-D model construction in early stage of geothermal exploration

    Science.gov (United States)

    Saputra, M. P.; Suryantini; Catigtig, D.; Regandara, R.; Asnin, S. N.; Pratama, A. B.

    2016-09-01

    Construction of geology, thermal anomaly and pressure distribution of a geothermal system in the early stage of exploration where data is limited is described using a 3-D software, Leapfrog Geothermal. The geological 3-D model was developed from a topographic map (derived from DEM data), geological map and literature studies reported in an early geological survey. The isothermal 3-D model was constructed using reservoir temperature estimation from geothermometry calculated from chemical analyses on surface manifestations, available shallow gradient temperature hole data and the normal gradient temperature (3°C/100m) for a nonthermal area. The isobaric 3-D model was built using hydrostatic pressure where the hydrostatic pressure is determined by the product of the fluid density, acceleration due to gravity, and depth. Fluid density is given by saturated liquid density as a function of temperature. There are some constraints on the modelling result such as (1) within the predicted reservoir, the geothermal gradient is not constant but continues to increase, thus, creating an anomalously high temperature at depth, and (2) the lithology model is made by interpolating and extrapolating cross-sections whereas usually only two to three geology sections were available for this study. Hence, the modeller must understand the geology. An additional cross section was developed by the modeller which may not be as suitable as the geologist constructed sections. The results of this study can be combined with geophysical data such as gravity, geomagnetic, micro-tremor and resistivity data. The combination of geological, geochemical, isothermal, isobaric and geophysical data could be used in (1) estimating the geometry and size of the geothermal reservoir, (2) predicting the depth of top reservoir, and (3) creating well prognosis for exploration and production wells.

  6. Mechanical modelling of the Singoe deformation zone. Site descriptive modelling Forsmark stage 2.1

    Energy Technology Data Exchange (ETDEWEB)

    Glamheden, Rune; Maersk Hansen, Lars; Fredriksson, Anders; Bergkvist, Lars; Markstroem, Ingemar; Elfstroem, Mats [Golder Associates AB (Sweden)

    2007-02-15

    This project aims at demonstrating the theoretical approach developed by SKB for determination of mechanical properties of large deformation zones, in particular the Singoe deformation zone. Up to now, only bedrock and minor deformation zones have been characterized by means of this methodology, which has been modified for this project. The Singoe deformation zone is taken as a reference object to get a more comprehensive picture of the structure, which could be incorporated in a future version of the SDM of Forsmark. Furthermore, the Singoe Zone has been chosen because of available data from four tunnels. Scope of work has included compilation and analysis of geological information from site investigations and documentation of existing tunnels. Results have been analyzed and demonstrated by means of RVS-visualization. Numerical modelling has been used to obtain mechanical properties. Numerical modelling has also been carried out in order to verify the results by comparison of calculated and measured deformations. Compilation of various structures in the four tunnels coincides largely with a magnetic anomaly and also with the estimated width. Based on the study it is clear that the Singoe deformation zone has a heterogeneous nature. The number of fracture zones associated with the deformation zone varies on either side of the zone, as does the transition zone between host rock and the Singoe zone. The overall impression from the study is that the results demonstrate that the methodology used for simulating of equivalent mechanical properties is an applicable and adequate method, also in case of large deformation zones. Typical rock mechanical parameters of the Singoe deformations that can be used in the regional stress model considering the zone to be a single fracture are: 200 MPa/m in normal stiffness, 10-15 MPa/m in shear stiffness, 0.4 MPa in cohesion and 31.5 degrees in friction angle.

  7. Osteopontin expression and localization of Ca++ deposits in early stages of osteoarthritis in a rat model.

    Science.gov (United States)

    Martínez-Calleja, América; Velasquillo, Cristina; Vega-López, Marco; Arellano-Jiménez, M Josefina; Tsutsumi-Fujiyoshi, Victor K; Mondragón-Flores, Ricardo; Kouri-Flores, Juan B

    2014-07-01

    Calcium deposits have been related to articular cartilage (AC) degeneration and have been observed in late stages of osteoarthritis (OA). However, the role of those deposits, whether they induce the OA pathogenesis or they appear as a consequence of such process, is still unknown. In this work, we present the kinetics of expression and tissue localisation of osteopontin (OPN), a mineralisation biomarker, and calcium deposits in samples from (normal, sham) and osteoarthritic cartilage (in a rat model). Immunohistochemical and Western blot assays for OPN, as well as Alizarin red staining for calcium deposits were performed; superficial, middle, and deep zones of AC were analysed. An increased expression of OPN and calcium deposits was found in the osteoarthritic cartilage compared with that of control groups, particularly in the superficial zone of AC in early stages of OA. In addition, the expression and localisation of OPN and calcium deposits during the OA pathogenesis suggest that the pathological AC mineralisation starts in the superficial zone during OA pathogenesis.

  8. Planning an Agricultural Water Resources Management System: A Two-Stage Stochastic Fractional Programming Model

    Directory of Open Access Journals (Sweden)

    Liang Cui

    2015-07-01

    Full Text Available Irrigation water management is crucial for agricultural production and livelihood security in many regions and countries throughout the world. In this study, a two-stage stochastic fractional programming (TSFP method is developed for planning an agricultural water resources management system under uncertainty. TSFP can provide an effective linkage between conflicting economic benefits and the associated penalties; it can also balance conflicting objectives and maximize the system marginal benefit with per unit of input under uncertainty. The developed TSFP method is applied to a real case of agricultural water resources management of the Zhangweinan River Basin China, which is one of the main food and cotton producing regions in north China and faces serious water shortage. The results demonstrate that the TSFP model is advantageous in balancing conflicting objectives and reflecting complicated relationships among multiple system factors. Results also indicate that, under the optimized irrigation target, the optimized water allocation rate of Minyou Channel and Zhangnan Channel are 57.3% and 42.7%, respectively, which adapts the changes in the actual agricultural water resources management problem. Compared with the inexact two-stage water management (ITSP method, TSFP could more effectively address the sustainable water management problem, provide more information regarding tradeoffs between multiple input factors and system benefits, and help the water managers maintain sustainable water resources development of the Zhangweinan River Basin.

  9. Transcriptome profiling of the cysticercus stage of the laboratory model Taenia crassiceps, strain ORF.

    Science.gov (United States)

    García-Montoya, Gisela M; Mesa-Arango, Jairo A; Isaza-Agudelo, Juan P; Agudelo-Lopez, Sonia P; Cabarcas, Felipe; Barrera, Luis F; Alzate, Juan F

    2016-02-01

    Neurocysticercosis (NC) is a serious public health problem mainly in developing countries. NC caused by the cysticercus stage from cestode Taenia solium is considered by the WHO and ITFDE as a potentially eradicable disease. Definitive diagnosis of NC is challenging because of the unspecific clinical manifestations such as the non-definitive evidence presented by neuroimaging (in most cases) and the lack of definitive serological test. Taenia crassiceps (ORF strain) is a cestode closely related to T. solium and it has frequently been used as a source of antigens for immunodiagnostics. A murine model to study host immune response to infection has also been established by using T. crassiceps. Despite the extensive use of T. crassiceps for research, molecular information for this cestode is scarce in public databases. With the aim of providing more extensive information on T. crassiceps biology, an RNA-seq experiment and subsequent bioinformatic transcriptome processing of this cestode parasite mRNA in its cysticercus stage were carried out. A total of 227,082 read/ESTs were sequenced using the 454-GS FLX Titanium technology and assembled into 10,787 contigs. This transcriptome dataset represents new and valuable molecular information of the cestode T. crassiceps (ORF). This information will substantially improve public information and will help to achieve a better understanding of the biology of T. crassiceps and to identify target proteins for serodiagnosis and vaccination.

  10. One- and two-stage Arrhenius models for pharmaceutical shelf life prediction.

    Science.gov (United States)

    Fan, Zhewen; Zhang, Lanju

    2015-01-01

    One of the most challenging aspects of the pharmaceutical development is the demonstration and estimation of chemical stability. It is imperative that pharmaceutical products be stable for two or more years. Long-term stability studies are required to support such shelf life claim at registration. However, during drug development to facilitate formulation and dosage form selection, an accelerated stability study with stressed storage condition is preferred to quickly obtain a good prediction of shelf life under ambient storage conditions. Such a prediction typically uses Arrhenius equation that describes relationship between degradation rate and temperature (and humidity). Existing methods usually rely on the assumption of normality of the errors. In addition, shelf life projection is usually based on confidence band of a regression line. However, the coverage probability of a method is often overlooked or under-reported. In this paper, we introduce two nonparametric bootstrap procedures for shelf life estimation based on accelerated stability testing, and compare them with a one-stage nonlinear Arrhenius prediction model. Our simulation results demonstrate that one-stage nonlinear Arrhenius method has significant lower coverage than nominal levels. Our bootstrap method gave better coverage and led to a shelf life prediction closer to that based on long-term stability data.

  11. Complex Dynamics of a Continuous Bertrand Duopoly Game Model with Two-Stage Delay

    Directory of Open Access Journals (Sweden)

    Junhai Ma

    2016-07-01

    Full Text Available This paper studies a continuous Bertrand duopoly game model with two-stage delay. Our aim is to investigate the influence of delay and weight on the complex dynamic characteristics of the system. We obtain the bifurcation point of the system respect to delay parameter by calculating. In addition, the dynamic properties of the system are simulated by power spectrum, attractor, bifurcation diagram, the largest Lyapunov exponent, 3D surface chart, 4D Cubic Chart, 2D parameter bifurcation diagram, and 3D parameter bifurcation diagram. The results show that the stability of the system depends on the delay and weight, in order to maintain stability of price and ensure the firm profit, the firms must control the parameters in the reasonable region. Otherwise, the system will lose stability, and even into chaos, which will cause fluctuations in prices, the firms cannot be profitable. Finally, the chaos control of the system is carried out by a control strategy of the state variables’ feedback and parameter variation, which effectively avoid the damage of chaos to the economic system. Therefore, the results of this study have an important practical significance to make decisions with multi-stage delay for oligopoly firms.

  12. Utility of Modeling End-Stage Liver Disease in Children with Chronic Liver Disease

    Directory of Open Access Journals (Sweden)

    Hamid Reza Kianifar

    2014-01-01

    Full Text Available Introduction: Chronic liver diseases consist of wide spectrum disorders that may be complicated by cirrhosis and therefore need to transplantation. The pediatric end-stage liver disease (PELD score and model of end-stage liver disease (MELD score has been used as predictors of mortality chronic liver diseases listed for liver transplantation. The aim of this study is evaluation of relation between PELDMELD score and evidence of cirrhosis in children with choronic liver disease.   Materials and Method: This cross-sectional study conducted on 106 patients of chronic liver disease referred to Ghaem Haspital, Mashhad University of Medical Science, Iran during 24 months period (2010-2013. PELD and MELD score were calculated for all patients. Clincal and patholoogical findings of cirrhosis were recorded.   Results: Mean age of patients was 68/3 ± 41.8 months. Mean PELDMELD score was -1/59± 9/64. There was significant correlation between PELDMELD score and clinical icter, spelenomegaly, evidence of hepatopulminary syndrome, esophageal varices, evidence of cirrhosis in tissue specimences.   Conclusion: PELDMELD score appear to be benefit for detection of cirrhotic children among paients with choronic liver disease.

  13. Metamnemonic Control Over the Discriminability of Memory Evidence: A Signal Detection Analysis of Warning Effects in the Associative List Paradigm

    Science.gov (United States)

    Starns, Jeffrey J.; Lane, Sean M.; Alonzo, Jill D.; Roussel, Cristine C.

    2007-01-01

    According to signal detection theory (SDT), retrieval warnings may decrease false memory in the associative list paradigm either by inducing a conservative criterion shift or by decreasing the amount of evidence that critical theme words were studied. Fitting a SDT model to 12 existing datasets revealed suggestive evidence that warnings impact…

  14. Optimal models with maximizing probability of first achieving target value in the preceding stages

    Institute of Scientific and Technical Information of China (English)

    林元烈; 伍从斌; 康波大

    2003-01-01

    Decision makers often face the need of performance guarantee with some sufficiently high proba-bility. Such problems can be modelled using a discrete time Markov decision process (MDP) with a probabilitycriterion for the first achieving target value. The objective is to find a policy that maximizes the probabilityof the total discounted reward exceeding a target value in the preceding stages. We show that our formula-tion cannot be described by former models with standard criteria. We provide the properties of the objectivefunctions, optimal value functions and optimal policies. An algorithm for computing the optimal policies forthe finite horizon case is given. In this stochastic stopping model, we prove that there exists an optimal deter-ministic and stationary policy and the optimality equation has a unique solution. Using perturbation analysis,we approximate general models and prove the existence of ε-optimal policy for finite state space. We give anexample for the reliability of the satellite systems using the above theory. Finally, we extend these results tomore general cases.

  15. Numerical framework to model temporally resolved multi-stage dynamic systems.

    Science.gov (United States)

    Zakharov, M N; Bhasin, S; Szafran, A T; Mancini, M A; Jasuja, R

    2012-11-01

    Numerical modeling of steroid hormone signaling presents an exciting challenge involving spatiotemporal coordination of multiple events. Ligand binding in cytoplasm triggers dissociation and/or association of coregulators which subsequently regulate DNA binding and transcriptional activity in nucleus. In order to develop a comprehensive multi-stage model, it is imperative to follow not only the transcriptional outcomes but also the intermediate protein complexes. Accordingly, we developed a software toolkit for simulating complex biochemical pathways as a set of non-linear differential equations in LabVIEW (Laboratory Virtual Instrumentation and Engineering Workbench, National Instruments, Austin, TX) environment. The toolkit is visual, highly modular, loosely coupled with the rest of LabVIEW, scalable and extensible. The toolkit can be used to develop and validate biochemical models and estimate model parameters from existing experimental data. We illustrate the application of the toolkit for simulation of steroid hormone response in cells, and demonstrate how the toolkit can be employed for other biological and chemical systems as well. The software module presented here can be used stand-alone as well as built into data collection and analysis applications.

  16. An elliptical-pore model for late-stage planar viscous sintering

    Science.gov (United States)

    Crowdy, Darren G.

    2004-02-01

    A simple ‘elliptical-pore model’ of the shrinkage of compressible pores in late-stage planar viscous sintering is proposed. The model is in the spirit of matched asymptotics and relies on splitting the flow into an ‘inner’ and ‘outer’ problem. The inner problem in the vicinity of any given pore involves solving for its free-surface evolution exactly using complex-variable methods. The outer flow due to all other pores is assumed to be given by an assembly of point sinks/sources. As a test of the model, the evolution of a singly infinite periodic row of compressible pores is considered in detail. The effectiveness of the simple model is tested by comparison with a full numerical simulation. A novel boundary integral method based on Cauchy potentials and conformal mapping is used. In the case of pores with constant pressure, it is found that pores shrink faster than if in isolation. Compressible pores obeying the ideal gas law are also studied and are found to tend to a quasi-steady non-circular state. A higher-order model is also presented and compared with numerical simulations of the viscous sintering of a doubly periodic array of pores in Stokes flow.

  17. Autobiography and Anorexia: A Qualitative Alternative to Prochaska and DiClemente's Stages of Change Model

    Directory of Open Access Journals (Sweden)

    Félix Díaz

    2012-11-01

    Full Text Available In this article, we propose a qualitative approach to the study of the ways in which people face good and poor health issues. During the last 30 years, Prochaska and DiClemente's "trans-theoretical model" (1982, 1983, 1984, 1986, 1992 has gained relevance as a model to assess disposition for change in patients. We revise the features of the model and its common techniques to assess stages of change, underlining its methodological and conceptual problems. Particularly, we discuss the paradoxes set by "pre-contemplation" as a concept; the exogenous definition of human problems in terms of institutional and clinical criteria; and the ambiguity of the model, where the purpose of accompanying and orienting the patient contrasts with the imposition of problem definitions and solution strategies. We propose a narrative analysis of autobiographies of patients as an alternative that recasts their own notions of "change," "problem," and "vital trajectory." We illustrate this possibility with the analysis of an autobiographic interview with a woman who has a history of anorexia. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1203209

  18. A cooperation model based on CVaR measure for a two-stage supply chain

    Science.gov (United States)

    Xu, Xinsheng; Meng, Zhiqing; Shen, Rui

    2015-07-01

    In this paper, we introduce a cooperation model (CM) for the two-stage supply chain consisting of a manufacturer and a retailer. In this model, it is supposed that the objective of the manufacturer is to maximise his/her profit while the objective of the retailer is to minimise his/her CVaR while controlling the risk originating from fluctuation in market demand. In reality, the manufacturer and the retailer would like to choose their own decisions as to wholesale price and order quantity to optimise their own objectives, resulting the fact that the expected decision of the manufacturer and that of the retailer may conflict with each other. Then, to achieve cooperation, the manufacturer and the retailer both need to give some concessions. The proposed model aims to coordinate the decisions of the manufacturer and the retailer, and balance the concessions of the two in their cooperation. We introduce an s* - optimal equilibrium solution in this model, which can decide the minimum concession that the manufacturer and the retailer need to give for their cooperation, and prove that the s* - optimal equilibrium solution can be obtained by solving a goal programming problem. Further, the case of different concessions made by the manufacturer and the retailer is also discussed. Numerical results show that the CM is efficient in dealing with the cooperations between the supplier and the retailer.

  19. A Risk-Based Interval Two-Stage Programming Model for Agricultural System Management under Uncertainty

    Directory of Open Access Journals (Sweden)

    Ye Xu

    2016-01-01

    Full Text Available Nonpoint source (NPS pollution caused by agricultural activities is main reason that water quality in watershed becomes worse, even leading to deterioration. Moreover, pollution control is accompanied with revenue’s fall for agricultural system. How to design and generate a cost-effective and environmentally friendly agricultural production pattern is a critical issue for local managers. In this study, a risk-based interval two-stage programming model (RBITSP was developed. Compared to general ITSP model, significant contribution made by RBITSP model was that it emphasized importance of financial risk under various probabilistic levels, rather than only being concentrated on expected economic benefit, where risk is expressed as the probability of not meeting target profit under each individual scenario realization. This way effectively avoided solutions’ inaccuracy caused by traditional expected objective function and generated a variety of solutions through adjusting weight coefficients, which reflected trade-off between system economy and reliability. A case study of agricultural production management with the Tai Lake watershed was used to demonstrate superiority of proposed model. Obtained results could be a base for designing land-structure adjustment patterns and farmland retirement schemes and realizing balance of system benefit, system-failure risk, and water-body protection.

  20. Risk model in stage IB1-IIB cervical cancer with positive node after radical hysterectomy

    Directory of Open Access Journals (Sweden)

    Chen Z

    2016-05-01

    Full Text Available Zhilan Chen,1,2,* Kecheng Huang,1,* Zhiyong Lu,1,3 Song Deng,1,4 Jiaqiang Xiong,1 Jia Huang,1 Xiong Li,5 Fangxu Tang,1 Zhihao Wang,6 Haiying Sun,1 Lin Wang,1 Shasha Zhou,1 Xiaoli Wang,1 Yao Jia,1 Ting Hu,1 Juan Gui,7 Dongyi Wan,1 Ding Ma,1 Shuang Li,1 Shixuan Wang11Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Techonology, Wuhan, 2Department of Obstetrics and Gynecology, Wuhan General Hospital of Guangzhou Military Command, Wuhan, 3Hubei Key Laboratory of Embryonic Stem Cell Research, Tai-He Hospital, Hubei University of Medicine, Shiyan, Hubei, 4Department of Obstetrics and Gynecology, University Hospital of Hubei University for Nationalities, Enshi, Hubei, 5Department of Obstetrics and Gynecology, Wuhan Central Hospital, Wuhan, 6Department of Pathology and Pathophysiology, Key Laboratory of Ministry of Education of China for Neurological Disorders, Huazhong University of Science and Techonology, Wuhan, 7Department of Obstetrics and Gynecology, Renmin Hospital, Wuhan University, Wuhan, People’s Republic of China*These authors contributed equally to this workAbstract: The purpose of this study was to identify risk factors in patients with surgically treated node-positive IB1-IIB cervical cancer and to establish a risk model for disease-free survival (DFS and overall survival (OS. A total of 170 patients who underwent radical hysterectomy and bilateral pelvic lymphadenectomy as primary treatment for node-positive International Federation of Gynaecology and Obstetrics (FIGO stage IB1-IIB cervical cancer from January 2002 to December 2008 were retrospectively analyzed. Five published risk models were evaluated in this population. The variables, including common iliac lymph node metastasis and parametrial invasion, were independent predictors of outcome in a multivariate analysis using a Cox regression model. Three distinct prognostic groups (low, intermediate, and high risk

  1. Design Considerations and Research Needs for Expanding the Current Perceptual Model of Spatial Orientation into an In-Cockpit Spatial Disorientation Warning System

    Science.gov (United States)

    2016-11-30

    USAARL Report No. 2017-07 Design Considerations and Research Needs for Expanding the Current Perceptual Model of Spatial Orientation into an In...19b. TELEPHONE NUMBER (Include area code) 30-11-2016 Final Design Considerations and Research Needs for Expanding the Current Perceptual Model of... International Journal of Human-Computer Studies, 58, 697-718. Kelley, A. M., Grandizio, C. M., Estrada, A., & Crowley, J. C. (2014). Tactile cues

  2. Earthquake Early Warning using a Seismogeodetic Approach: An operational plan for Cascadia

    Science.gov (United States)

    Crowell, B. W.; Bodin, P.; Vidale, J. E.; Schmidt, D. A.; Melbourne, T. I.; Scrivner, C. W.; Santillan, V. M.; Szeliga, W. M.; Minson, S. E.; Bock, Y.; Melgar, D.

    2013-12-01

    We present an operational plan for implementing combined seismic and geodetic time series in an earthquake early warning system for Cascadia. The Cascadian subduction zone presents one of the greatest risks for a megaquake in the continental United States. Ascertaining the full magnitude and extent of large earthquakes is problematic for earthquake early warning systems due to instability when double integrating strong-motion records to ground displacement. This problem can be mitigated by augmenting earthquake early warning systems with real-time GPS data, allowing for the progression and spatial extent of large earthquakes to be better resolved due to GPS's ability to measure both dynamic and permanent displacements. The Pacific Northwest Seismic Network (PNSN) at the University of Washington is implementing an integrated seismogeodetic approach to earthquake early warning. Regional GPS data are provided by the Pacific Northwest Geodetic Array (PANGA) at Central Washington University. Precise Point Positioning (PPP) solutions are sent from PANGA to the PNSN through JSON formatted streams and processed with a Python-based quality control (QC) module. The QC module also ingest accelerations from PNSN seismic stations through the Earthworm seismic acquisition and processing system for the purpose of detecting outliers and Kalman filtering when collocated instruments exist. The QC module outputs time aligned and cleaned displacement waveforms to ActiveMQ, an XML-based messaging broker that is currently used in seismic early warning architecture. Earthquake characterization modules read displacement information from ActiveMQ when triggered by warnings from ElarmS earthquake early warning algorithm. Peak ground displacement and P-wave scaling relationships from Kalman filtered waveforms provide initial magnitude estimates. Additional modules perform more complex source modeling such as centroid moment tensors and slip inversions that characterize the full size and

  3. Numerical 3D Model of Viscous Turbulent Flow in One Stage Gas Turbine and Its Experimental Validation

    Institute of Scientific and Technical Information of China (English)

    Yu.V. STARODUBTSEV; I.G. GOGOLEV; V.G. SOLODOV

    2005-01-01

    @@ The paper describes 3D numerical Reynolds Averaged Navier-Stokes (RANS) model and approximate sector approach for viscous turbulent flow through flow path of one stage axial supercharge gas turbine of marine diesel engine. Computational data are tested by comparison with experimental data. The back step flow path opening and tip clearance jet are taken into account.This approach could be applied for variety of turbine theory and design tasks: for offer optimal design in order to minimize kinetic energy stage losses; for solution of partial supply problem; for analysis of flow pattern in near extraction stages; for estimation of rotational frequency variable forces on blades; for sector vane adjustment (with thin leading edges mainly), for direct flow modeling in the turbine etc. The development of this work could be seen in the direction of unsteady stage model application.

  4. Early warnings and missed alarms for abrupt monsoon transitions

    Science.gov (United States)

    Thomas, Z. A.; Kwasniok, F.; Boulton, C. A.; Cox, P. M.; Jones, R. T.; Lenton, T. M.; Turney, C. S. M.

    2015-12-01

    Palaeo-records from China demonstrate that the East Asian Summer Monsoon (EASM) is dominated by abrupt and large magnitude monsoon shifts on millennial timescales, switching between periods of high and weak monsoon rains. It has been hypothesized that over these timescales, the EASM exhibits two stable states with bifurcation-type tipping points between them. Here we test this hypothesis by looking for early warning signals of past bifurcations in speleothem δ18O records from Sanbao Cave and Hulu Cave, China, spanning the penultimate glacial cycle. We find that although there are increases in both autocorrelation and variance preceding some of the monsoon transitions during this period, it is only immediately prior to the abrupt monsoon shift at the penultimate deglaciation (Termination II) that statistically significant increases are detected. To supplement our data analysis, we produce and analyse multiple model simulations that we derive from these data. We find hysteresis behaviour in our model simulations with transitions directly forced by solar insolation. However, signals of critical slowing down, which occur on the approach to a bifurcation, are only detectable in the model simulations when the change in system stability is sufficiently slow to be detected by the sampling resolution of the data set. This raises the possibility that the early warning "alarms" were missed in the speleothem data over the period 224-150 kyr and it was only at the monsoon termination that the change in the system stability was sufficiently slow to detect early warning signals.

  5. Food safety knowledge and practice by the stages of change model in school children.

    Science.gov (United States)

    Kang, Nam-E; Kim, Ju Hyeon; Kim, Young Soon; Ha, Ae Wha

    2010-12-01

    In this study, 342 grade 4-6 elementary school students in Gyeonggi-do were recruited to determine their readiness to change food safety behavior and to compare their food safety knowledge and practices by the stages of change. The subjects were divided into three stages of change; the percentage of stage 1 (precontemplation) was 10.1%, the percentage of stage 2 (contemplation and preparation) was 62.4%, and that of stage 3 (action and maintenance) was 27.5%. Food safety knowledge scores in stage 3 (4.55) or stage 2 (4.50) children were significantly higher than those in stage 1 children (4.17) (P food safety behavior items "hand washing practice" and "avoidance of harmful food" were significantly different among the three groups (P food safety knowledge and practice. Age was significantly and negatively correlated with the total food safety behavior score (r = -0.142, P food safety (P < 0.01).

  6. Global Dynamics of a Predator-Prey Model with Stage Structure and Delayed Predator Response

    Directory of Open Access Journals (Sweden)

    Lili Wang

    2013-01-01

    Full Text Available A Holling type II predator-prey model with time delay and stage structure for the predator is investigated. By analyzing the corresponding characteristic equations, the local stability of each of feasible equilibria of the system is discussed. The existence of Hopf bifurcations at the coexistence equilibrium is established. By means of the persistence theory on infinite dimensional systems, it is proven that the system is permanent if the coexistence equilibrium exists. By using Lyapunov functionals and LaSalle’s invariance principle, it is shown that the predator-extinction equilibrium is globally asymptotically stable when the coexistence equilibrium is not feasible, and the sufficient conditions are obtained for the global stability of the coexistence equilibrium.

  7. A STAGE-STRUCTURED SI ECO-EPIDEMIOLOGICAL MODEL WITH TIME DELAY AND IMPULSIVE CONTROLLING

    Institute of Scientific and Technical Information of China (English)

    Xinzhu MENG; Lansun CHEN

    2008-01-01

    This paper formulates a robust stage-structured SI eco-epidemiological model with periodic constant pulse releasing of infectious pests with pathogens. The authors show that the conditions for global attractivity of the 'pest-eradication' periodic solution and permanence of the system depend on time delay, hence, the authors call it "profitless". Further, the authors present a pest management strategy in which the pest population is kept under the economic threshold level (ETL) when the pest population is uniformly persistent. By numerical analysis, the authors also show that constant maturation time delay for the susceptible pests and pulse releasing of the infectious pests can bring obvious effects on the dynamics of system.

  8. Global Stability of a Predator-prey Model with Stage Structure

    Institute of Scientific and Technical Information of China (English)

    WANG Li-li; XU Rui

    2015-01-01

    A Holling type III predator-prey model with stage structure for prey is investi-gated. By analyzing the corresponding characteristic equations, the local stability of each of feasible equilibria of the system is discussed. By using the uniformly persistence theory, the system is proven to be permanent if the coexistence equilibrium exists. By using Lyapunov functionals and LaSalle’s invariance principle, it is shown that the two boundary equilibria is globally asymptotically stable when the coexistence equilibrium is not feasible. By using compound matrix theory, the sucient conditions are obtained for the global stability of the coexistence equilibrium. At last, numerical simulations are carried out to illustrate the main results.

  9. Model for End-Stage Liver Disease and liver cirrhosis-related complications.

    Science.gov (United States)

    Bertot, Luis Calzadilla; Gomez, Eduardo Vilar; Almeida, Linnet Alonso; Soler, Enrique Arus; Perez, Luis Blanco

    2013-06-01

    The Model for End-Stage Liver Disease (MELD) score has gained wide acceptance for predicting survival in patients undergoing liver transplantation. The strength of this score remains in the mathematical formula derived from a multivariate Cox regression analysis; it is a continuous scale and lacks a ceiling or a floor effect with a wide range of discrimination. It is based on objective, reproducible, and readily available laboratory data and the wide range of samples which have been validated. Liver cirrhosis complications such as ascites, encephalopathy, spontaneous bacterial peritonitis and variceal bleeding were not considered in the MELD score underestimating their direct association with the severity of liver disease. In this regard, several recent studies have shown that clinical manifestations secondary to portal hypertension are good prognostic markers in cirrhotic patients and may add additional useful prognostic information to the current MELD. We review the feasibility of MELD score as a prognostic predictor in patients with liver cirrhosis-related complications.

  10. Multi-stage IT project evaluation: The flexibility value obtained by implementing and resolving Berk, Green and Naik (2004) model

    Science.gov (United States)

    Abid, Fathi; Guermazi, Dorra

    2009-11-01

    In this paper, we evaluate a multi-stage information technology investment project, by implementing and resolving Berk, Green and Naik's (2004) model, which takes into account specific features of IT projects and considers the real option to suspend investment at each stage. We present a particular case of the model where the project value is the solution of an optimal control problem with a single state variable. In this case, the model is more intuitive and tractable. The case study confirms the practical potential of the model and highlights the importance of the real-option approach compared to classical discounted cash flow techniques in the valuation of IT projects.

  11. On the modeling of a single-stage, entrained-flow gasifier using Aspen Custom Modeler (ACM)

    Energy Technology Data Exchange (ETDEWEB)

    Kasule, J.; Turton, R.; Bhattacharyya, D.; Zitney, S.

    2010-01-01

    Coal-fired gasifiers are the centerpiece of integrated gasification combined cycle (IGCC) power plants. The gasifier produces synthesis gas that is subsequently converted into electricity through combustion in a gas turbine. Several mathematical models have been developed to study the physical and chemical processes taking place inside the gasifier. Such models range from simple one-dimensional (1D) steady-state models to sophisticated dynamic 3D computational fluid dynamics (CFD) models that incorporate turbulence effects in the reactor. The practical operation of the gasifier is dynamic in nature but most 1D and some higher-dimensional models are often steady state. On the other hand, many higher order CFD-based models are dynamic in nature, but are too computationally expensive to be used directly in operability and controllability dynamic studies. They are also difficult to incorporate in the framework of process simulation software such as Aspen Plus Dynamics. Thus lower-dimensional dynamic models are still useful in these types of studies. In the current study, a 1D dynamic model for a single-stage, downward-firing, entrained-flow GE-type gasifier is developed using Aspen Custom Modeler{reg_sign} (ACM), which is a commercial equation-based simulator for creating, editing, and re-using models of process units. The gasifier model is based on mass, momentum, and energy balances for the solid and gas phases. The physical and chemical reactions considered in the model are drying, devolatilization/pyrolysis, gasification, combustion, and the homogeneous gas phase reactions. The dynamic gasifier model is being developed for use in a plant-wide dynamic model of an IGCC power plant. For dynamic simulation, the resulting highly nonlinear system of partial differential algebraic equations (PDAE) is solved in ACM using the well-known Method of Lines (MoL) approach. The MoL discretizes the space domain and leaves the time domain continuous, thereby converting the PDAE to

  12. Two-Stage orders sequencing system for mixed-model assembly

    Science.gov (United States)

    Zemczak, M.; Skolud, B.; Krenczyk, D.

    2015-11-01

    In the paper, the authors focus on the NP-hard problem of orders sequencing, formulated similarly to Car Sequencing Problem (CSP). The object of the research is the assembly line in an automotive industry company, on which few different models of products, each in a certain number of versions, are assembled on the shared resources, set in a line. Such production type is usually determined as a mixed-model production, and arose from the necessity of manufacturing customized products on the basis of very specific orders from single clients. The producers are nowadays obliged to provide each client the possibility to determine a huge amount of the features of the product they are willing to buy, as the competition in the automotive market is large. Due to the previously mentioned nature of the problem (NP-hard), in the given time period only satisfactory solutions are sought, as the optimal solution method has not yet been found. Most of the researchers that implemented inaccurate methods (e.g. evolutionary algorithms) to solving sequencing problems dropped the research after testing phase, as they were not able to obtain reproducible results, and met problems while determining the quality of the received solutions. Therefore a new approach to solving the problem, presented in this paper as a sequencing system is being developed. The sequencing system consists of a set of determined rules, implemented into computer environment. The system itself works in two stages. First of them is connected with the determination of a place in the storage buffer to which certain production orders should be sent. In the second stage of functioning, precise sets of sequences are determined and evaluated for certain parts of the storage buffer under certain criteria.

  13. Clinical applications of the Model for End-Stage Liver Disease (MELD in hepatic medicine

    Directory of Open Access Journals (Sweden)

    Lau T

    2013-02-01

    Full Text Available Tsang Lau, Jawad AhmadDivision of Liver Diseases, Mount Sinai School of Medicine, New York, USAAbstract: The Model for End-Stage Liver Disease (MELD score incorporates serum bilirubin, creatinine, and the international normalized ratio (INR into a formula that provides a continuous variable that is a very accurate predictor of 90-day mortality in patients with cirrhosis. It is currently utilized in the United States to prioritize deceased donor organ allocation for patients listed for liver transplantation. The MELD score is superior to other prognostic models in patients with end-stage liver disease, such as the Child–Turcotte–Pugh score, since it uses only objective criteria, and its implementation in 2002 led to a sharp reduction in the number of people waiting for liver transplant and reduced mortality on the waiting list without affecting posttransplant survival. Although mainly adopted for use in patients waiting for liver transplant, the MELD score has also proved to be an effective predictor of outcome in other situations, such as patients with cirrhosis going for surgery and patients with fulminant hepatic failure or alcoholic hepatitis. Several variations of the original MELD score, involving the addition of serum sodium or looking at the change in MELD over time, have been examined, and these may slightly improve its accuracy. The MELD score does have limitations in situations where the INR or creatinine may be elevated due to reasons other than liver disease, and its implementation for organ allocation purposes does not take into consideration several conditions that benefit from liver transplantation. The application of the MELD score in prioritizing patients for liver transplantation has been successful, but further studies and legislation are required to ensure a fair and equitable system.Keywords: MELD score, liver transplantation

  14. Properties of type IV plaster considering variation in the mold/model position during setting stage

    Directory of Open Access Journals (Sweden)

    Tarcisio José de Arruda Paes Junior

    2010-04-01

    Full Text Available Objective: To assess the influence of the position of the mold during the setting stage of type IV stone plaster Durone (Dentsply Ind. Com., Rio de Janeiro, Brazil, on the following properties: surface hardness and roughness. Methods: For the roughness test, two groups (n=6 in the form of pellets were prepared. In the first group, the surface of the base of the device was turned down during the plaster setting stage (N, in the second group this position was inverted, which has been described as an act of capsize it (E. For analysis, a roughness meter with reading precision of 0.01 μm was used. With regard to the hardness analysis, two groups with conical-shaped samples were obtained. The plasters were left to set under the same conditions of the mold/model position described for the previous experiment. Hardness measurement was performed in a durometer with a spherical penetrating tip for Rockwell readout. Three measurements were performed for each test specimen in both tests. Results: The hardness (N - 39.8, standard deviation = 3.3, E - 30.8, standard deviation = 5.6 and roughness data (N - 0.67, standard deviation = 0.17, E - 0.74, standard deviation = 0.13 submitted to the Student’s-t test (5% showed no statistically significant differences for the roughness test (0.489, but showed statistically significant differences for the hardness test (0.014. Conclusion: The variation in the mold/model position influenced the final characteristics of the specimens in terms of hardness, since those obtained with the capsize technique showed lower surface hardness, whereas for roughness these differences were not statistically significant.

  15. What Are the Warning Signs of Stroke?

    Science.gov (United States)

    ... Cardiovascular Conditions What Are the Warning Signs of Stroke? Brain tissue affected by blockage Stroke is the fifth leading cause of death in ... over 55 years old have more chance of stroke, and the risk gets greater as you get ...

  16. Drug Abuse Warning Network (DAWN-2008)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  17. Drug Abuse Warning Network (DAWN-2010)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  18. Drug Abuse Warning Network (DAWN-2011)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  19. National Weather Service County Warning Area Boundaries

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains polygons corresponding to the County Warning Areas (CWAs) of each Weather Forecast Office (WFO) in the National Weather Service (NWS).

  20. FDA Warns About Stem Cell Claims

    Science.gov (United States)

    ... Home For Consumers Consumer Updates FDA Warns About Stem Cell Claims Share Tweet Linkedin Pin it More sharing ... blood-forming system. back to top Regulation of Stem Cells FDA regulates stem cells in the U.S. to ...

  1. Drug Abuse Warning Network (DAWN-2004)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  2. Drug Abuse Warning Network (DAWN-2009)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  3. Drug Abuse Warning Network (DAWN-2007)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  4. Drug Abuse Warning Network (DAWN-2006)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  5. Drug Abuse Warning Network (DAWN-2005)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  6. Development of Flood Warning System

    Directory of Open Access Journals (Sweden)

    Joy J. Labo,

    2016-01-01

    Full Text Available Community-based early warning systems (CBEWS is a “people-centered” system and empowers individuals and communities threatened by hazards to act on sufficient time and in an appropriate manner to reduce the possibility of personal injury, loss of life, damage to property, environment and loss of livelihood. These things lead to the development of the device necessary for the protection of the community against flood hazards as it allows people to get prepared with sufficient time. An alarm system was developed to monitor the water level on Salog River that overflows during heavy rains. The water level sensors were submerged in a canal of water to test the functionality of the device before its installation. Computer programs were created to enhance the monitoring of water level: the River Monitor Software and the Water Level Monitor. The LED arrays emit light according to water level; green for low, orange for medium, and red for high. A siren also alarms with different intervals (30 seconds for low, 15 seconds for medium, and a continuous alarm for high. Automatic emergency lighting was integrated in the design and lights up during power outages powered by rechargeable sealed battery that charges when ac power is supplied to the device. Levels were established based on available data; low water level means awareness; medium water level means preparedness and high water level means immediate response is necessary.

  7. Initial stage of growth of single-walled carbon nanotubes: modeling and simulations.

    Science.gov (United States)

    Chaudhuri, I; Yu, Ming; Jayanthi, C S; Wu, S Y

    2014-03-19

    Because there are different pathways to grow carbon nanotubes (CNTs), a common mechanism for the synthesis of CNTs does not likely exist. However, after carbon atoms are liberated from carbon-containing precursors by catalysts or from pure carbon systems, a common feature, the nucleation of CNTs by electron mediation, does appear. We studied this feature using the initial stage of growth of single wall CNTs (SWCNTs) by transition metal nano-particle catalysts as the working example. To circumvent the bottleneck due to the size and simulation time, we used a model in which the metal droplet is represented by a jellium, and the effect of collisions between the carbon atoms and atoms of the catalyst is captured by charge transfers between the jellium and the carbon. The simulations were performed using a transferable semi-empirical Hamiltonian to model the interactions between carbon atoms in jellium. We annealed different initial configurations of carbon clusters in jellium as well as in a vacuum. We found that in jellium, elongated open tubular structures, precursors to the growth of SWCNTs, are formed. Our model was also shown to be capable of mimicking the continued growth when more atoms were placed near the open end of the tubular structure.

  8. Design of formative assessment model for professional behavior using stages of change theory.

    Science.gov (United States)

    Hashemi, Akram; Mirzazadeh, Azim; Shirazi, Mandana; Asghari, Fariba

    2016-01-01

    Background: Professionalism is a core competency of physicians. This study was conducted to design a model for formative assessment of professional commitment in medical students according to stages of change theory. Methods: In this qualitative study, data were collected through literature review & focus group interviews in the Tehran University of Medical Sciences in 2013 and analyzed using content analysis approach. Results: Review of the literature and results of focus group interviews led to design a formative assessment model of professional commitment in three phases, including pre-contemplation, contemplation, and readiness for behavior change that each one has interventional and assessment components. In the second phase of the study, experts' opinion collected in two main categories: the educational environment (factors related to students, students' assessment and educational program); and administrative problems (factors related to subcultures, policymakers or managers and budget). Moreover, there was a section of recommendations for each category related to curriculum, professors, students, assessments, making culture, the staff and reinforcing administrative factors. Conclusion: This type of framework analysis made it possible to develop a conceptual model that could be effective on forming the professional commitment and behavioral change in medical students.

  9. Three-stage Method for Identifying the Dynamic Model Parameters of Stranded Wire Helical Springs

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yu; WANG Shilong; ZHOU Jie; LI Chuan; SUN Shouli

    2015-01-01

    The dynamic behavior of the stranded wire helical spring is described by a modified Bouc-Wen model while the model parameters must be identified using an identification method and experimental data. Existing identification methods usually relies either solely nonlinear iterative algorithms or manually trial and error. Therefore, the identification process can be rather time consuming and effort taking. As a result, these methods are not ideal for engineering applications. To come up with a more practical method, a three-stage identification method is proposed. Periodic loading and identification simulations are carried out to verify the effectiveness of the proposed method. Noises are added to the simulated data to test the performance of the proposed method when dealing with noise contaminated data. The simulation results indicate that the proposed method is able to give satisfying results when the noise levels are set to be 0.01, 0.03, 0.05 and 0.07. In addition, the proposed method is also applied to experimental data and compared with an existing method. The experimental data is acquired through a periodic loading test. The experiment results suggest that the proposed method features better accuracy compared with the existing method. An effective approach is proposed for identifying the model parameters of the stranded wire helical spring.

  10. Statistical Model of the Early Stage of nucleus-nucleus collisions with exact strangeness conservation

    CERN Document Server

    Poberezhnyuk, R V; Gorenstein, M I

    2015-01-01

    The Statistical Model of the Early Stage, SMES, describes a transition between confined and deconfined phases of strongly interacting matter created in nucleus-nucleus collisions. The model was formulated in the late 1990s for central Pb+Pb collisions at the CERN SPS energies. It predicted several signals of the transition (onset of deconfinement) which were later observed by the NA49 experiment. The grand canonical ensemble was used to calculate entropy and strangeness production. This approximation is valid for reactions with mean multiplicities of particles carrying conserved charges being significantly larger than one. Recent results of NA61/SHINE on hadron production in inelastic p+p interactions suggest that the deconfinement may also take place in these reactions. However, in this case mean multiplicity of particles with non-zero strange charge is smaller than one. Thus for the modeling of p+p interactions the exact strangeness conservation has to be implemented in the SMES. This extension of the SMES ...

  11. A Two-Stage Queue Model to Optimize Layout of Urban Drainage System considering Extreme Rainstorms

    Directory of Open Access Journals (Sweden)

    Xinhua He

    2017-01-01

    Full Text Available Extreme rainstorm is a main factor to cause urban floods when urban drainage system cannot discharge stormwater successfully. This paper investigates distribution feature of rainstorms and draining process of urban drainage systems and uses a two-stage single-counter queue method M/M/1→M/D/1 to model urban drainage system. The model emphasizes randomness of extreme rainstorms, fuzziness of draining process, and construction and operation cost of drainage system. Its two objectives are total cost of construction and operation and overall sojourn time of stormwater. An improved genetic algorithm is redesigned to solve this complex nondeterministic problem, which incorporates with stochastic and fuzzy characteristics in whole drainage process. A numerical example in Shanghai illustrates how to implement the model, and comparisons with alternative algorithms show its performance in computational flexibility and efficiency. Discussions on sensitivity of four main parameters, that is, quantity of pump stations, drainage pipe diameter, rainstorm precipitation intensity, and confidence levels, are also presented to provide guidance for designing urban drainage system.

  12. A stage-structured, spatially explicit migration model for Myotis bats: mortality location affects system dynamics

    Science.gov (United States)

    Erickson, Richard A.; Thogmartin, Wayne E.; Russell, Robin E.; Diffendorfer, James E.; Jennifer A. Szymanski,; ,

    2014-01-01

    Bats are ecologically and economically important species because they consume insects, transport nutrients, and pollinate flowers.  Many species of bats, including those in the Myotis genus, are facing population decline and increased extinction risk.  Despite these conservation concerns, few models exist for providing insight into the population dynamics of bats in a spatially explicit context.  We developed a model for bats by considering the stage-structured colonial life history of Myotis bats with their annual migration behavior.  This model provided insight into network dynamics.  We specifically focused on two Myotis species living in the eastern United States: the Indiana bat (M. sodalis), which is a Federally listed endangered species, and the little brown bat (M. lucifugus), which is under consideration for listing as an endangered species.  We found that multiple equilibria exist for the local, migratory subpopulations even though the total population was constant.  These equilibria suggest the location and magnitude of stressors such as White-nose Syndrome, meteorological phenomena, or impacts of wind turbines on survival influence system dynamics and risk of population extirpation in difficult to predict ways.

  13. Early stages of insulin fibrillogenesis examined with ion mobility mass spectrometry and molecular modelling.

    Science.gov (United States)

    Cole, Harriet; Porrini, Massimiliano; Morris, Ryan; Smith, Tom; Kalapothakis, Jason; Weidt, Stefan; Mackay, C Logan; MacPhee, Cait E; Barran, Perdita E

    2015-10-21

    A prevalent type of protein misfolding causes the formation of β-sheet-rich structures known as amyloid fibrils. Research into the mechanisms of fibril formation has implications for both disease prevention and nanoscale templating technologies. This investigation into the aggregation of insulin utilises ion mobility mass spectrometry coupled with molecular modelling to identify and characterise oligomers formed during the 'lag' phase that precedes fibril growth. High resolution mass spectrometry and collision induced dissociation is used to unequivocally assign species as m/z coincident multimers or confomers, providing a robust analytical approach that supports the use of molecular dynamics to atomistically resolve the observed oligomers. We show that insulin oligomerises to form species In where 2 ≤ n ≤ 12 and within this set of oligomers we delineate over 60 distinct conformations, the most dominant of which are compact species. Modelling trained with experimental data suggests that the dominant compact dimers are enriched in β-sheet secondary structure and dominated by hydrophobic interactions, and provides a linear relationship between Rg and collision cross section. This approach provides detailed insight to the early stages of assembly of this much studied amyloidogenic protein, and can be used to inform models of nucleation and growth.

  14. Study on Early Warning Model of Legal Risks on Human Resources of Productive Employees in Petroleum Enterprises%石油企业生产型员工人力资源法律风险预警模型研究--以M 公司为例

    Institute of Scientific and Technical Information of China (English)

    胥莉; 杨帆; 张惠琴

    2015-01-01

    The study established early warning model of legal risk on human resources for productive employees of the petroleum enterprises .It completed screening index through the Delphi method ,determined the index weight through Analytic Hierarchy Process ,and calculated the risk level through Fuzzy comprehensive evaluation method .It also validated risk early warning model through the M company's Oil exploration project abroad .The manager can test legal risk of staff's site management based on the model and issue a warning signal .%针对石油企业生产型员工这一特殊群体,建立了人力资源法律风险预警模型。采用德尔菲法完成指标筛选确定指标预警区间,通过层次分析法计算指标权重,运用模糊数学综合评价法计算风险等级。并以我国M公司境外石油勘探项目为例对风险预警模型进行验证。管理者依据模型可以测试该类员工现场管理的法律风险,发出预警信号。

  15. The SuperNova Early Warning System

    OpenAIRE

    Scholberg, K.

    2008-01-01

    A core collapse in the Milky Way will produce an enormous burst of neutrinos in detectors world-wide. Such a burst has the potential to provide an early warning of a supernova's appearance. I will describe the nature of the signal, the sensitivity of current detectors, and SNEWS, the SuperNova Early Warning System, a network designed to alert astronomers as soon as possible after the detected neutrino signal.

  16. Internet sex and dating sites need warnings.

    Science.gov (United States)

    Tenore, Peter L

    2006-01-01

    For this issue's Commentary column, Peter L. Tenore, MD, discusses risk for infection with HIV or acquisition of sexually transmitted diseases associated with the use of the Internet to find sexual partners and presents results of an informal survey to determine whether Internet sites used to find sexual partners provide warnings about sexually transmitted diseases and HIV. He also calls for the operators of such sites to add warnings to their sites.

  17. 基于分布式水文模型的山洪预警临界雨量分析--以涔水南支小流域为例%Flash Flood Early-Warning Indicators Based on Distributed Hydrological Model-A Case Study in South Branch of Censhui Watershed

    Institute of Scientific and Technical Information of China (English)

    李昌志; 郭良; 刘昌军; 孙东亚

    2015-01-01

    基于我国山洪灾害雨量预警的需求,介绍了采用分布式水文模型分析临界雨量的基本思路与方法,以湖南省涔水南支小流域为例,探讨了流域内3个典型预警对象动态临界雨量的确定方法并获得了相应成果。分析认为,分布式水文模型可以较为详细地设置流域各部分产流、汇流以及洪水特征,有利于模拟山丘区小流域洪水,是同时分析多个对象临界雨量的有效方法;分析预警地点的预警流量是非常重要的前提和基础,流域汇流时间是非常重要的预警时段,应根据流域特征和防灾对象特点,确定一系列典型的预警时段;流域尺度土壤含水量对临界雨量有重要影响。%Using DHM (Distribution Hydrological Model) technique with detailed sub-basin delineation, this study introduces basic concepts and methods of analyzing warning indicators for flash flood early warning. Taking south branch of Censhui watershed in Hunan Province as an example, 3 typical early warning indicators for flash flood dynamic early warning were investigated. This research il ustrates that detailed watershed characteristics can be modeled in-depth by further delineate the watershed into smal er sub-basins to simulate spatial distribution of various basin parameters. The resulted runoff and flood hydrographs show better accuracy at al 3 early warning stations. It further confirms that time of concentration of a watershed is an important factor to warning rainfal duration, and the antecedent soil moisture condition of the watershed has significant impact to the critical rainfal .

  18. A Walk through TRIDEC's intermediate Tsunami Early Warning System

    Science.gov (United States)

    Hammitzsch, M.; Reißland, S.; Lendholt, M.

    2012-04-01

    integrates OGC Sensor Web Enablement (SWE) compliant sensor systems for the rapid detection of hazardous events, like earthquakes, sea level anomalies, ocean floor occurrences, and ground displacements. Using OGC Web Map Service (WMS) and Web Feature Service (WFS) spatial data are utilized to depict the situation picture. The integration of a simulation system to identify affected areas is considered using the OGC Web Processing Service (WPS). Warning messages are compiled and transmitted in the OASIS Common Alerting Protocol (CAP) together with addressing information defined via the OASIS Emergency Data Exchange Language - Distribution Element (EDXL-DE). The first system demonstrator has been designed and implemented to support plausible scenarios demonstrating the treatment of simulated tsunami threats with an essential subset of a National Tsunami Warning Centre (NTWC). The feasibility and the potentials of the implemented approach are demonstrated covering standard operations as well as tsunami detection and alerting functions. The demonstrator presented addresses information management and decision-support processes in a hypothetical natural crisis situation caused by a tsunami in the Eastern Mediterranean. Developments of the system are based to the largest extent on free and open source software (FOSS) components and industry standards. Emphasis has been and will be made on leveraging open source technologies that support mature system architecture models wherever appropriate. All open source software produced is foreseen to be published on a publicly available software repository thus allowing others to reuse results achieved and enabling further development and collaboration with a wide community including scientists, developers, users and stakeholders. This live demonstration is linked with the talk "TRIDEC Natural Crisis Management Demonstrator for Tsunamis" (EGU2012-7275) given in the session "Architecture of Future Tsunami Warning Systems" (NH5.7/ESSI1.7).