WorldWideScience

Sample records for active defrost scheme

  1. An active defrost scheme with a balanced energy consumption and food quality loss in supermarket refrigeration systems

    DEFF Research Database (Denmark)

    Cai, Junping; Stoustrup, Jakob; Rasmussen, Bjarne Dindler

    2008-01-01

    This paper introduces food quality as a new parameter, together with energy, to determine an optimal cooling time between defrost cycles. A new defrost-on-demand scheme is proposed. It uses a feedback loop consisting of on-line model updating and estimation as well as a model based optimization. ...

  2. Minimizing quality deteriorations of refrigerated foodstuffs as a side effect of defrosting

    DEFF Research Database (Denmark)

    Cai, Junping; Stoustrup, Jakob

    2008-01-01

    This paper proposes an optimization scheme for traditional refrigeration systems with hysteresis controllers and scheduled defrosts. It aims at minimizing the side effect of defrost cycles on the storage quality of refrigerated foodstuffs in supermarkets. By utilizing the thermal mass of air and...... products inside a display cabinet, this optimization scheme forces the compressor to work harder and cool down more prior to the scheduled defrosts, thus guaranteeing the product temperature after defrost cycles still to be within a controlled safe level....

  3. Defrost Temperature Termination in Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL; Sharma, Vishaldeep [ORNL

    2011-11-01

    The objective of this project was to determine the potential energy savings associated with implementing demand defrost strategies to defrost supermarket refrigerated display case evaporators, as compared to the widely accepted current practice of controlling display case defrost cycles with a preset timer. The defrost heater energy use of several representative display case types was evaluated. In addition, demand defrost strategies for refrigerated display cases as well as those used in residential refrigerator/freezers were evaluated. Furthermore, it is anticipated that future work will include identifying a preferred defrost strategy, with input from Retail Energy Alliance members. Based on this strategy, a demand defrost system will be designed which is suitable for supermarket refrigerated display cases. Limited field testing of the preferred defrost strategy will be performed in a supermarket environment.

  4. Supermarket Defrost Cycles As Flexible Reserve

    DEFF Research Database (Denmark)

    Pedersen, Rasmus; Sloth, Christoffer; Wisniewski, Rafal;

    2015-01-01

    This work analyses how supermarket defrost cycles can be used as flexible reserve in a smart grid context. The consumption flexibility originates from being able to shift defrost cycles in time, while adhering to the underlying refrigeration systems constraints. It is shown how this time constrai......This work analyses how supermarket defrost cycles can be used as flexible reserve in a smart grid context. The consumption flexibility originates from being able to shift defrost cycles in time, while adhering to the underlying refrigeration systems constraints. It is shown how this time...

  5. Energy demand and comparison of current defrosting technologies of frozen raw materials in defrosting tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Bezovsky, Marek [Slovenske Elektrarne, a.s., Power Plant Vojany, 076 73 Vojany (Slovakia); Stricik, Michal [The Faculty of Business Economics with seat in Kosice of University of Economics in Bratislava (Slovakia); Prascakova, Maria [Institute of Geotechnics, Slovak Academy of Sciences, Kosice (Slovakia)

    2010-08-15

    The optimization process of coal defrosting in defrosting tunnels is solved in this article. Individual technical solutions of defrosting tunnels, as well as energy demands, are dealt with in this report. Defrosting tunnels are used for the defrosting of deep-frozen substrates like coal, ore or powdery substances. There are two different ways of defrosting. The first one is based on convective heating and the second one on radiant heating. Nowadays, convective heating is used much more than radiant heating. However, theory and practice show that the radiant heating is much more efficient. The aim of this article is to describe the design and construction of a multifunctional method of a defrosting tunnel. In the second stage we make experimental measurements of convective and radiant methods of defrosting on a built model. Its third aim is to make energy and economy assessments of defrosting process on the model. Finally, to implement the acquired knowledge in the practice, determining the conditions, in which the change of present-day convective defrosting technology to the new radiant technology becomes effective. (author)

  6. The Effect of Various Methods of Defrosting on Microbial Contamination of Frozen Banana Shrimp (Penaeus merguiensis)

    Institute of Scientific and Technical Information of China (English)

    Ladan Mansouri-Najand

    2012-01-01

    Objective: Background and aim: The most common and the best way of preventing microbial decay of marine foods is using freezing technology and the cycles and methods of defrosting have considerable effect on microbial changes of frozen shrimp. Shrimp is one of the marine foods that due to high active water (aw) and neutral PH and autolytic enzymes have high decay. Thus, in this study the effect of various methods of defrosts on microbial contamination of shrimp was investigated. Methods: This study was an empirical design on Penaeus merguiensis. The shrimps were divided into three groups including 1- peeled and headless (PUD), 2- Complete, 3- Headless (with skin) being frosted and defrosted in three cycles. Each group of shrimp was classified in terms of the type of defrosting method in three groups as 1- Microwave, 2- Refrigerator, 3-Water and were investigated in 3 cycles with the interval of 4 days. In this investigation, the total bacteria, Psychrophil bacteria, coliforms and Staphylococcus aureus were counted in private culture mediums. For data analysis, repeated measure Anova was used. Results: All the bacteria including Psychrophil bacteria, coliforms and Staphylococcus aureus during the cycles had significant reduction process and this reduction showed significant reduction in complete shrimp and defrosting with refrigerator compared to other groups (P<0.05). Conclusions: According to the results, complete shrimp was the best kind of shrimp in terms of microbial load. Thus, avoiding temperature changes during transportation and avoiding unduly defrosts in maintaining the quality of the frozen shrimp is proposed.

  7. Bonus schemes and trading activity

    NARCIS (Netherlands)

    Pikulina, E.S.; Renneboog, L.D.R.; ter Horst, J.R.; Tobler, P.N.

    2014-01-01

    Little is known about how different bonus schemes affect traders' propensity to trade and which bonus schemes improve traders' performance. We study the effects of linear versus threshold bonus schemes on traders' behavior. Traders buy and sell shares in an experimental stock market on the basis of

  8. Development of a demand defrost controller. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Borton, D.N. [Power Kinetics, Troy, NY (United States); Walker, D.H. [Foster-Miller, Inc., Waltham, MA (United States)

    1993-10-01

    The purpose of this project was to develop and commercialize a demand defrost controller that initiates defrosts of refrigeration systems only when required. The standard method of control is a time clock that usually defrosts too often, which wastes energy. The controller developed by this project uses an algorithm based on the temperature difference between the discharge and return of the display case air curtain along with several time settings to defrost only when needed. This controller was field tested in a supermarket where it controlled defrost of the low-temperature display cases. According to test results the controller could reduce annual energy consumption by 20,000 and 62,000 kWh for hot gas and electric defrost, respectively. The controller saves electric demand as well as energy, is adaptable to ambient air conditions, and provides valuable savings throughout the year. The savings are greatest for low-temperature systems that use the most energy. A less tangible benefit of the demand controller is the improvement in food quality that results from fewer defrosts.

  9. Measured impacts of supermarket humidity level on defrost performance and refrigerating system energy use

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, H.I.; Khattar, M.

    1999-07-01

    This paper presents field-monitor data from two supermarkets where the impact of space humidity on refrigerating system energy use was evaluated. Direct digital control (DDC) systems were used at both stores to collect 15-minute monitored data. At Store A in Minneapolis, the DDC system was used to monitor system performance as well as to implement temperature-terminated control in place of time-terminated control on 16 refrigerated zones using hot gas defrost. At Store B in Indianapolis, the DDC system was used to quantify the performance trends for the single compressor rack system with electric defrost. The results at Store B showed that refrigerating system energy use decreases by nearly 10 kWh/day for each 1% drop in space relative humidity, or about 0.4% of average annual system energy use. This value includes the impact of reduced latent loads, the reduction in direct energy use and imposed load from reduced electric defrost heater operation, and the smaller imposed load from reduced anti-sweat heater energy use. The measured reductions agree well with the impact predicted using the calculation methods developed by Howell (1933b) in ASHRAE Research Project 596. At Store A, the measured data show that implementing temperature-terminated defrost reduced refrigerating system energy use by nearly 70 kWh/day over the winter period when the average space humidity was 22% RH. The savings from temperature-terminated defrost increase by 4 kWh/day per each 1% drop in relative humidity. At both stores, the same type of mechanical controls were used to duty cycle the anti-sweat heaters based on store dew point. Anti-sweat heater electricity use was observed to decrease by 4.6 kWh/day at Store B and 3.4 kWh/day at Store A for each 1% drop in relative humidity. At Store A, a more aggressive control scheme was implemented with the DDC system that reduced anti-sweat heater energy use by 7.8 kWh/day per % RH. The more aggressive control approach was reported to properly

  10. An experimental study on defrosting heat supplies and energy consumptions during a reverse cycle defrost operation for an air source heat pump

    International Nuclear Information System (INIS)

    For a space heating air source heat pump (ASHP) unit, when its outdoor coil surface temperature is below both the air dew point temperature and the freezing point of water, frost will form on its outdoor coil surface. Frosting affects its operational performance and energy efficiency. Therefore, periodic defrosting is necessary. Currently, the most widely used standard defrosting method for ASHP units is reverse cycle defrost. The energy that should have been used for space heating is used to melt frost, vaporize the melted frost off outdoor coil surface and heat ambient air during defrosting. It is therefore necessary to study the sources of heat supplies and the end-uses of the heat supplied during a reverse cycle defrost operation. In this paper, firstly, an experimental setup is described and experimental procedures are detailed. This is followed by reporting the experimental results and the evaluation of defrosting efficiency for the experimental ASHP unit. Finally, an evaluation of defrosting heat supplies and energy consumptions during a revere cycle defrost operation for the experimental ASHP unit is presented. The experimental and evaluation results indicated that the heat supply from indoor air contributed to 71.8% of the total heat supplied for defrosting and 59.4% of the supplied energy was used for melting frost. The maximum defrosting efficiency could be up to 60.1%. - Highlights: ► Heat supply and consumption during reverse cycle defrost was experimentally studied. ► Indoor air contributed to >70% of total heat supply when indoor fan was turned on. ► ∼60% of the supplied energy was used for melting frost. ► Alternate heat supply other than indoor air should be explored.

  11. Frost formation and defrost control parameters for open multideck refrigerated food display cabinets

    Energy Technology Data Exchange (ETDEWEB)

    Tassou, S.A.; Datta, D. [Brunel Univ., Dept. of Mechanical Engineering, Uxbridge (United Kingdom); Marriott, D. [Safeway Stores plc, Hayes (United Kingdom)

    2001-04-03

    In order to achieve the required air and product temperatures in refrigerated food display cabinets, the evaporator coils, which are normally located in the base of the cabinets, operate at temperatures below the freezing point of water. The air which is circulated over the evaporator coil is cooled below its dew point and water vapour present in the air condenses and eventually freezes on the coil surface. With continuous operation of the coil, frost will accumulate on the coil surface leading to a decrease both in the air flowrate and in the overall heat transfer coefficient. In order to maintain satisfactory performance, evaporator coils are defrosted periodically. Although different defrost control strategies can be employed, for simplicity and cost considerations, defrosting in supermarket refrigeration systems is usually controlled by a pre-set time cycle. It is widely acknowledge, however, that time-based defrost may cause a number of unnecessary defrost cycles and this reduces the energy efficiency of the refrigeration systems as well as the accuracy of temperature control of the cabinets. Implementing defrost only when it is needed or on 'demand' should reduce the number of defrost cycles and lead to savings in energy and improved product quality. This paper reports on field and experimental investigations on the processes of frosting and defrosting of medium-temperature display cabinet evaporator coils. The results show that for medium-temperature refrigeration applications where the environment temperature is kept reasonably constant, the store humidity is the primary parameter influencing the rate of frost formation. Using relative humidity as a control parameter the defrost frequency can be reduced considerably without affecting cabinet performance and product integrity. Alongside the effect of relative humidity, the paper also considers the effects of other performance parameters on the processes of frosting and defrosting such as cooling

  12. 49 CFR 571.103 - Standard No. 103; Windshield defrosting and defogging systems.

    Science.gov (United States)

    2010-10-01

    ... defrosting and defogging systems. S1. Scope. This standard specifies requirements for windshield defrosting... passenger vehicles, trucks, and buses. S3. Definitions. Road load means the power output required to move a... driveline friction, rolling friction, and air resistance. S4. Requirements. (a) Except as provided...

  13. Continuous heating of an air-source heat pump during defrosting and improvement of energy efficiency

    International Nuclear Information System (INIS)

    Highlights: • The newly designed dual hot gas spray defrosting method was examined. • Uninterrupted heating of an air source heat pump during defrosting. • We compared newly designed dual hot gas and traditional reverse cycle defrost. • Total energy efficiency was increased by 8% compared to traditional method. - Abstract: During winter operation, an air-source heat pump extracts heat from the cold outside air and releases the heat into the living space. At certain outside air conditions, when it operates in heating mode, frost can form on the air-cooled heat exchanger, decreasing the heating performance. Conventionally, reverse-cycle defrosting (RCD) has been the common method of frost removal. But this method requires the interruption of heating during defrosting, as well as a period of time to reheat the cooled pipes of the indoor units after defrosting. In this study, a new technology called continuous heating was developed, which utilize only a hot gas bypass valve to remove the frost from the outdoor heat exchanger and thus enabling the supply of hot air to indoors without any interruption. For this, a new high temperature and low pressure gas bypass method was designed, which is differentiated from the common high pressure hot gas bypass methods by its use of low pressure. Various refrigerant mass flow distributions were examined, and the most effective defrosting mass flow was 50% in this case. Heating capacity was increased by 17% because of continuous heating, and the cumulated energy efficiency was increased by 8% compared to the traditional reverse cycle defrosting over 4 h including two defrost operations. Also, cumulated energy efficiency was increased by 27% compared to electronic heaters that supply the same heating capacity during defrosting. By this new technology, it has been proved that continuous heating and energy savings could be achieved without adopting expensive technologies

  14. An active interferometer-stabilization scheme with linear phase control

    DEFF Research Database (Denmark)

    Vardhan Krishnamachari, Vishnu; Andresen, Esben Ravn; Potma, Eric Olaf

    2006-01-01

    We report a simple and robust computer-based active interferometer stabilization scheme which does not require modulation of the interfering beams and relies on an error signal which is linearly related to the optical path difference. In this setup, a non-collinearly propagating reference laser...... beam stabilizes the interference output of the laser light propagating collinearly through the interferometer. This stabilization scheme enables adjustable phase control with 20 ms switching times in the range from 0.02π radians to 6π radians at 632.8 nm....

  15. Design and Analysis of a Multiscale Active Queue Management Scheme

    Institute of Scientific and Technical Information of China (English)

    Qi-Jin Ji; Yong-Qiang Dong

    2006-01-01

    Since Internet is dominated by TCP-based applications, active queue management (AQM) is considered as an effective way for congestion control. However, most AQM schemes suffer obvious performance degradation with dynamic traffic. Extensive measurements found that Internet traffic is extremely bursty and possibly self-similar. We propose in this paper a new AQM scheme called multiscale controller (MSC) based on the understanding of traffic burstiness in multiple time scale. Different from most of other AQM schemes, MSC combines rate-based and queue-based control in two time scales. While the rate-based dropping on burst level (large time scales) determines the packet drop aggressiveness and is responsible for low and stable queuing delay, good robustness and responsiveness, the queue-based modulation of the packet drop probability on packet level (small time scales) will bring low loss and high throughput. Stability analysis is performed based on a fluid-flow model of the TCP/MSC congestion control system and simulation results show that MSC outperforms many of the current AQM schemes.

  16. A universal encoding scheme for MIMO transmission using a single active element for PSK modulation schemes

    DEFF Research Database (Denmark)

    Alrabadi, Osama; Papadias, C.B.; Kalis, A.;

    2009-01-01

    A universal scheme for encoding multiple symbol streams using a single driven element (and consequently a single radio frequency (RF) frontend) surrounded by parasitic elements (PE) loaded with variable reactive loads, is proposed in this paper. The proposed scheme is based on creating a MIMO...

  17. Does a physical activity referral scheme improve the physical activity among routine primary health care patients?

    OpenAIRE

    Leijon, Matti E; Bendtsen, Preben; Nilsen, Per; Festin, Karin; Ståhle, A

    2009-01-01

    Physical activity referral (PAR) schemes or concepts occur in varying forms. Because few physical activity intervention studies have been carried out in routine health care settings, it is difficult to translate research findings into daily practice. The aim of this study was to analyze the effectiveness of a PAR scheme implemented in routine primary health care. The study did not include a control group and was based on the ordinary staff's work efforts and follow-up measures. During a 2-yea...

  18. A novel defrosting method using heat energy dissipated by the compressor of an air source heat pump

    International Nuclear Information System (INIS)

    Highlights: • A novel defrosting method using heat energy dissipated by the compressor was developed and examined. • During the defrosting process, mean temperature difference between the air entering and leaving the indoor coil reached 4.1 °C. • Compared to the traditional method, defrosting time was shortened by 65% while the resuming heating period disappeared. • For the defrosting operation, the total energy consumption was less than 27.9% compared to the traditional method. - Abstract: When an air source heat pump (ASHP) unit is used for space heating at low ambient temperatures in winter, frost may form on its outdoor coil surface. Since the accumulated frost adversely affects its performance and energy efficiency, periodic defrosting of the outdoor coil is necessary. Currently, the reverse-cycle defrosting (RCD) method is widely used for the defrosting of ASHP. However, this operation interrupts space heating during the defrosting process. A time lag occurs to resume heating at end of the defrosting cycle. Moreover, frequent reversing of the 4-way valve may cause mass leakage of the refrigerant, even make the system unsafe. Furthermore, some amount of heat is dissipated to the atmosphere through the compressor casing. To improve the defrosting process and use this waste heat, a novel ASHP unit is developed. The space is heated during the defrosting process using the heat dissipated by the compressor. Experiments using both the RCD method and the novel reverse cycle defrosting (NRCD) method developed in this study are conducted on an ASHP unit of 8.9 kW nominal heating capacity. The experimental results indicated that in the NRCD method, the discharge and suction pressures are increased by 0.33 MPa and 0.14 MPa, respectively, the defrosting time is shortened by 65% while the resuming heating period vanished with the NRCD method, and that the total energy consumption in comparison to RCD method is reduced by 27.9% during the period which is composed

  19. Performances of air source heat pump system for a kind of mal-defrost phenomenon appearing in moderate climate conditions

    International Nuclear Information System (INIS)

    Highlights: ► Mal-defrost performances of ASHP in moderate environment are investigated. ► The system COP decreases to 2.3 under environment temperature of 7.9 °C. ► The decrease of the ASHP heating capacity can get to 43.4%. ► The origins of this special mal-defrost phenomenon were discussed. ► Suggestions were proposed to modify the current defrosting control strategies. - Abstract: To quantify the performance drop of the air source heat pump (ASHP) system under a special kind of mal-defrost phenomenon appearing in moderate climate conditions, a field test was conducted for 8 days at the initial stage of a heating season in Beijing, China. The mal-defrost was found with the more than 60% frosted area of the outdoor heat exchanger after the system running 5 days. During this frosting period, the system COP was significantly degraded, only 2.3 under an environment temperature of 7.9 °C. Comparing the test data before and after frosting, it was found that the mal-defrost decreased the COP up to 40.4% and the heating capacity to 43.4%. Such low energy efficiency continued quite a long time until the defrost control was started up manually by the authors. After defrosting, the COP reclaimed to the normal level of 5.0. The origins of this special mal-defrost phenomenon were discussed. And some suggestions were proposed to modify the current defrosting control strategy, which were helpful to avoid the mal-defrost problem in the current ASHP system and therefore improve the system performances

  20. A new numerical scheme for the simulation of active magnetic regenerators

    DEFF Research Database (Denmark)

    Torregrosa-Jaime, B.; Engelbrecht, Kurt; Payá, J.;

    2014-01-01

    A 1D model of a parallel-plate active magnetic regenerator (AMR) has been developed based on a new numerical scheme. With respect to the implicit scheme, the new scheme achieves accurate results, minimizes computational time and prevents numerical errors. The model has been used to check...

  1. Influence of supermarket environmental parameters on the frosting and defrosting of vertical multideck display cabinets

    Energy Technology Data Exchange (ETDEWEB)

    Tassou, S.A.; Datta, D.

    1999-07-01

    This paper reports on results of investigations to identify and quantify the effect of in-store environmental conditions on frost accumulation on the evaporator coils of open multideck refrigerated display cabinets. Field and environmental chamber-based tests have shown that both ambient relative humidity and temperature of a store have a significant effect on the rate of frost formation on the evaporator coils, with the effect of relative humidity being much more pronounced than the effect of temperature. In supermarkets where a fixed-time defrost control strategy is employed, it is possible that cabinets are defrosted too infrequently at high relative humidities, resulting in high product temperatures, and too frequently at low relative humidities, resulting in excessive energy consumption. Considerable opportunity exists for the application of more sophisticated defrost control strategies, both to save energy and improve temperature control.

  2. Control strategy and experimental study on a novel defrosting method for air-source heat pump

    International Nuclear Information System (INIS)

    A new defrosting method - the sensible heat defrosting method, aiming at shelving the various disadvantages of the conventional reverse cycle defrosting was proposed in this paper. The mechanism and process of this method was analysed. To guarantee the reliability, the self-organizing control algorithm with self-learning function was introduced based on the cardinal fuzzy control algorithm. Moreover, the control strategy was enacted; the corresponding self-organizing fuzzy control system was developed; the Micro Controller Unit (MCU) based control unit was accomplished; and the experimental study was conducted to investigate the sample machine of air-source heat pump system. The results of the experiments showed that the self-organizing control algorithm has good control characteristic and effect. On one hand, the adverse shock from the conventional reverse cycle defrosting to the refrigeration system could be avoided through this proposed method; on the other hand, the 'oil rush' could also be eliminated. Besides, the thermal comfort could be greatly improved since the temperature fluctuation range of the supplied water is narrowed by applying this new method in practice.

  3. An experimental investigation on reverse-cycle defrosting performance for an air source heat pump using an electronic expansion valve

    International Nuclear Information System (INIS)

    Highlights: ► We experimentally studied the defrost performance under two EEV control strategies. ► The two EEV control strategies were fully open and controlled by a DS controller. ► When the EEV was under the DS controller, higher defrosting efficiency was obtained. -- Abstract: When an air source heat pump (ASHP) operates in heating mode, frost can be accumulated on the surface of its finned outdoor coil. Frosting deteriorates the operation and energy efficiency of the ASHP and periodic defrosting becomes necessary. Currently the most widely used standard defrosting method for ASHPs is reverse cycle defrost. On the other hand, electronic expansion valves (EEVs) are commonly used in heat pump/refrigeration systems, including ASHP units, as throttle regulators of refrigerant flow. This paper reports on an experimental investigation of the performance of a reverse cycle defrost operation for a 6.5 kW experimental heating capacity residential ASHP whose outdoor coil had four-parallel refrigerant circuits, and with an EEV as the refrigerant flow throttle regulator. The detailed descriptions of the experimental ASHP unit and the experimental procedures of ASHP are firstly presented. This is followed by reporting the comparative experiments of two control strategies for the EEV to investigate their effects on defrosting performance: the EEV being fully open and the EEV being regulated by a degree of refrigerant superheat (DS) controller. Experimental results revealed that when the EEV was regulated by the DS controller during defrosting, a higher defrosting efficiency and less heat wastage would be resulted in.

  4. An efficient numerical scheme for the simulation of parallel-plate active magnetic regenerators

    DEFF Research Database (Denmark)

    Torregrosa-Jaime, Bárbara; Corberán, José M.; Payá, Jorge;

    2015-01-01

    A one-dimensional model of a parallel-plate active magnetic regenerator (AMR) is presented in this work. The model is based on an efficient numerical scheme which has been developed after analysing the heat transfer mechanisms in the regenerator bed. The new finite difference scheme optimally...

  5. Does Mixed Reimbursement Schemes Affect Hospital Activity and Productivity? An Analysis of the Case of Denmark

    DEFF Research Database (Denmark)

    Hansen, Xenia Brun; Bech, Mickael; Jakobsen, Mads Leth;

    2013-01-01

    The majority of public hospitals in Scandinavia are reimbursed through a mixture of two prospective reimbursement schemes, block grants (a fixed amount independent of the number of patients treated) and activity-based financing (ABF). This article contributes theoretically to the existing...... whether different incentives affects the performance of hospitals regarding activity and productivity differently. Information on Danish reimbursement schemes has been collected from documents provided by the regional governments and through interviews with regional administrations. The data cover...

  6. A comparative study of the active force control schemes applied to robot arm

    International Nuclear Information System (INIS)

    In this paper, a comparative study of three different types of active force control (AFC) schemes applied to a robotic arm is described. The study particularly focuses on the techniques to compute the estimated inertia matrix (ΙΝ) of a robotic manipulator necessary for the execution of the AFC strategy since the computation of (ΙΝ) is the common central theme to all AFC-based schemes. The first of the three AFC schemes is based on the conventional method of obtaining (ΙΝ), the second uses artificial neural network while the third incorporates an iterative learning algorithm. The study also discusses the characteristics of the (ΙΝ) curves obtained, the trajectory track performance of the schemes and the effects of the modelled disturbances. The robustness of all the AFC schemes are also ascertained in the study. (Author)

  7. Knowledge-Based Trajectory Error Pattern Method Applied to an Active Force Control Scheme

    Directory of Open Access Journals (Sweden)

    Endra Pitowarno, Musa Mailah, Hishamuddin Jamaluddin

    2012-08-01

    Full Text Available The active force control (AFC method is known as a robust control scheme that dramatically enhances the performance of a robot arm particularly in compensating the disturbance effects. The main task of the AFC method is to estimate the inertia matrix in the feedback loop to provide the correct (motor torque required to cancel out these disturbances. Several intelligent control schemes have already been introduced to enhance the estimation methods of acquiring the inertia matrix such as those using neural network, iterative learning and fuzzy logic. In this paper, we propose an alternative scheme called Knowledge-Based Trajectory Error Pattern Method (KBTEPM to suppress the trajectory track error of the AFC scheme. The knowledge is developed from the trajectory track error characteristic based on the previous experimental results of the crude approximation method. It produces a unique, new and desirable error pattern when a trajectory command is forced. An experimental study was performed using simulation work on the AFC scheme with KBTEPM applied to a two-planar manipulator in which a set of rule-based algorithm is derived. A number of previous AFC schemes are also reviewed as benchmark. The simulation results show that the AFC-KBTEPM scheme successfully reduces the trajectory track error significantly even in the presence of the introduced disturbances.Key Words:  Active force control, estimated inertia matrix, robot arm, trajectory error pattern, knowledge-based.

  8. Demonstration of a 4-Sensor Folded Sangac Sensor Array with Active Phase Biasing Scheme

    Institute of Scientific and Technical Information of China (English)

    Zhang-Qi Song; Ming-Ye Yang; Xue-Liang Zhang; Yong-Ming Hu

    2008-01-01

    A 4-sensor folded Sagnae sensor array with an active phase biasing scheme is presented. The overlapping of the signal and noise pulse is avoided through a time division multiplexing scheme and the noise pulses is eliminated almost completely. The scheme can address 16 sensors when the repeat frequency of input pulse is at 68.3 kHz. The alternative phase bias technique is demonstrated, which can provide sensors with stable phase bias. The future benefit of this technique is that the 1/f noise in the circuit can be suppressed.

  9. A Lightning Activity Forecast Scheme Developed for Summer Thunderstorms in South China

    Institute of Scientific and Technical Information of China (English)

    WANG Fei; ZHANG Yijun; DONG Wansheng

    2010-01-01

    Based on the relationship between lightning flash density and radar echoes and a statistical analysis using satellite and radar observations,a scheme was introduced into the mesoscale model GRAPES(Global and Regional Assimilation and PrEdiction System)to forecast the cloud to ground(CC)flash activities.Because the relationship is a necessary but not sufficient condition for lightning,an additional constraint condition related to temperature of cloud top is added into the scheme to determine whether the lightning activity really occurs.Only if the lightning activity meets the criterion to occur,the CG flash density in a grid is considered to be valid.This was proved to be necessary for reducing the false prediction.Two cases that occurred on the edge of the subtropical high in coastal regions of South China were simulated to examine the efficiency of the scheme.The results showed that the scheme was capable of forecasting lightning activities in South China.The simulated lightning areas agreed with the CG flash observations,and the CG flash density forecast by the model was also consistent with observational results in magnitude.In consideration of the forecast aging of the explicit cloud microphysical scheme in GRAPES,lightning activities can now be forecast accurately within 6 h.

  10. Smartphone-Based Patients' Activity Recognition by Using a Self-Learning Scheme for Medical Monitoring.

    Science.gov (United States)

    Guo, Junqi; Zhou, Xi; Sun, Yunchuan; Ping, Gong; Zhao, Guoxing; Li, Zhuorong

    2016-06-01

    Smartphone based activity recognition has recently received remarkable attention in various applications of mobile health such as safety monitoring, fitness tracking, and disease prediction. To achieve more accurate and simplified medical monitoring, this paper proposes a self-learning scheme for patients' activity recognition, in which a patient only needs to carry an ordinary smartphone that contains common motion sensors. After the real-time data collection though this smartphone, we preprocess the data using coordinate system transformation to eliminate phone orientation influence. A set of robust and effective features are then extracted from the preprocessed data. Because a patient may inevitably perform various unpredictable activities that have no apriori knowledge in the training dataset, we propose a self-learning activity recognition scheme. The scheme determines whether there are apriori training samples and labeled categories in training pools that well match with unpredictable activity data. If not, it automatically assembles these unpredictable samples into different clusters and gives them new category labels. These clustered samples combined with the acquired new category labels are then merged into the training dataset to reinforce recognition ability of the self-learning model. In experiments, we evaluate our scheme using the data collected from two postoperative patient volunteers, including six labeled daily activities as the initial apriori categories in the training pool. Experimental results demonstrate that the proposed self-learning scheme for activity recognition works very well for most cases. When there exist several types of unseen activities without any apriori information, the accuracy reaches above 80 % after the self-learning process converges.

  11. Smartphone-Based Patients' Activity Recognition by Using a Self-Learning Scheme for Medical Monitoring.

    Science.gov (United States)

    Guo, Junqi; Zhou, Xi; Sun, Yunchuan; Ping, Gong; Zhao, Guoxing; Li, Zhuorong

    2016-06-01

    Smartphone based activity recognition has recently received remarkable attention in various applications of mobile health such as safety monitoring, fitness tracking, and disease prediction. To achieve more accurate and simplified medical monitoring, this paper proposes a self-learning scheme for patients' activity recognition, in which a patient only needs to carry an ordinary smartphone that contains common motion sensors. After the real-time data collection though this smartphone, we preprocess the data using coordinate system transformation to eliminate phone orientation influence. A set of robust and effective features are then extracted from the preprocessed data. Because a patient may inevitably perform various unpredictable activities that have no apriori knowledge in the training dataset, we propose a self-learning activity recognition scheme. The scheme determines whether there are apriori training samples and labeled categories in training pools that well match with unpredictable activity data. If not, it automatically assembles these unpredictable samples into different clusters and gives them new category labels. These clustered samples combined with the acquired new category labels are then merged into the training dataset to reinforce recognition ability of the self-learning model. In experiments, we evaluate our scheme using the data collected from two postoperative patient volunteers, including six labeled daily activities as the initial apriori categories in the training pool. Experimental results demonstrate that the proposed self-learning scheme for activity recognition works very well for most cases. When there exist several types of unseen activities without any apriori information, the accuracy reaches above 80 % after the self-learning process converges. PMID:27106584

  12. A study of the reverse cycle defrosting performance on a multi-circuit outdoor coil unit in an air source heat pump – Part I: Experiments

    International Nuclear Information System (INIS)

    Highlights: ► We experimental study the defrosting performance on a multi-circuit outdoor coil unit in an ASHP unit. ► We find that defrosting is quicker on the airside of upper circuits than that on the lower circuits. ► We discuss the effects of downwards flowing of the melted frost along the outdoor coil surface on defrosting performance. -- Abstract: When an air source heat pump (ASHP) unit operates in heating mode, frost can be accumulated on the surface of its finned outdoor coil which normally has multiple parallel circuits on its refrigerant side for minimized refrigerant pressure loss and enhanced heat transfer efficiency. On its airside, however, there is usually no segmentation corresponding to the number of refrigerant circuit. Frosting deteriorates the operation and energy efficiency of the ASHP unit and periodic defrosting becomes necessary. Currently the most widely used standard defrosting method for ASHPs is reverse cycle defrost. This paper, the first part of a two-part series, reports on the experimental part of a study of the reverse cycle defrosting performance on a multi-circuit outdoor coil unit in an experimental 6.5 kW heating capacity residential ASHP unit. Firstly the experimental ASHP unit is described and experimental procedures detailed. Secondly, the experimental results are reported. This is followed by the discussion on the effects of downwards flowing of the melted frost along a multi-circuit outdoor coil surface on defrosting performance. Finally, the evaluation of the defrosting efficiency for the experimental ASHP unit is provided. In the second part of the series, a modeling analysis on the effects of downwards flowing of the melted frost along the multi-circuit outdoor coil surface on defrosting performance of the experimental ASHP unit will be presented.

  13. Design and Performance Research of a Chaotic Secure Communication Scheme Based on Active-Passive Synchronization

    Institute of Scientific and Technical Information of China (English)

    ZHANGXingzhou; SONGChunyan; QIAOYulong

    2005-01-01

    A new scheme of chaotic secure communication based on active-passive synchronization is proposed.Not only the complexity of system is reduced, but also the capability is enhanced. At the same time, it does not destroy the correlation. The experimental results show that the proposed method can recover signals well. Because the system is very sensitive to the parameters, which reaches the level of asynchronous method, and it can resist the attack of decryption methods to chaotic synchronization, the scheme is safe.

  14. Experimental analysis of an air-source transcritical CO2 heat pump water heater using the hot gas bypass defrosting method

    International Nuclear Information System (INIS)

    When an air-source CO2 heat pump water heater operates at low ambient temperatures in cold regions in winter, frost can form on the coil surface of its outdoor evaporator. The frost substantially affects the operating performance and energy efficiency of CO2 heat pump water heaters and hence periodic defrosting is essential. In this paper, defrosting characteristics of an air-source CO2 heat pump water heater using the hot gas bypass defrosting method is experimentally studied at different ambient conditions. An experimental setup is developed for this purpose and experimental procedures are detailed. Thereafter, the pressure and temperature in the outdoor evaporator, at the compressor and gas cooler outlets are evaluated during the defrosting period. An energy analysis is then performed of different system components during the defrosting process. Results indicate that 35% of the supplied energy is used for melting the frost, and 7.6% is used to heat the evaporator tubes and fins. About 57.4% of the supplied energy is consumed to increase the internal energy of the gas cooler. The typical efficiency of the hot gas bypass defrosting method applied in the CO2 heat pump water heater ranges from 30 to 40%. It increases with increasing dry bulb temperature, and decreasing relative humidity. - Highlights: • Hot gas bypass defrosting method for transcritical CO2 heat pumps was studied. • An experimental setup was established in an environmental laboratory. • The temperature, pressure and energy consumptions in the system were analysed. • The efficiency of hot gas bypass defrosting method ranged from 30 to 40%. • The effect of ambient conditions on defrosting efficiency was investigated

  15. Camera Sensor Activation Scheme for Target Tracking in Wireless Visual Sensor Networks

    OpenAIRE

    Wei Li

    2013-01-01

    Target tracking has become an elementary task in wireless visual sensor networks (WVSNs). In this paper, we propose a camera sensor activation scheme for target tracking in WVSN. Our objective is to balance the tradeoff between the accuracy of target tracking and the resources of networks. By studying the sensing model and deployments of cameras, an observation correlation coefficient is derived to describe the correlation characteristics of visual information observed by cameras with overlap...

  16. Engineering and manufacture of a high-efficiency, automatic defrosting refrigerator-freezer

    Science.gov (United States)

    Bohman, R. H.; Harrison, R. L.

    The engineering effort and method of manufacture used to build thirty-six high efficiency, automatic defrosting, refrigerator-freezers are described. It was determined that an 18 cubic ft. model would be suited for the market test. Calculations were made to establish its physical size and insulation thicknesses were specified. The heat leaks were calculated using a computer program and the calculation established the expected heat flow when operated in a 90 F ambient with a 5 F freezer and a 38 F fresh food compartment. The program was also used to determine expected performance when various refrigeration system components and configurations were considered. The engineering design and the component selection are discussed. The sequences of prototype testing are followed.

  17. Beginning of fish defrosting by using non-destructive ultrasonic technique

    International Nuclear Information System (INIS)

    During the experiments carried out on the monitoring and the study of fish defrosting by an ultrasonic technique, we have difficulties in detecting the beginning of the thawing which is an important criterion of fish quality control. To address this problem, we use the Singular Value Decomposition method (SVD) which is a mathematical tool that permits to separate the high and low energies of an histogram. The image representing low energy signals indicates the start of the thawing by showing an echo that was hidden in the original image for cod fish. Using transducers for central frequencies above 500 kHz the observed results are not very good. Therefore, this method is suitable for fish which fat content is medium or low.

  18. Agent-based power sharing scheme for active hybrid power sources

    Science.gov (United States)

    Jiang, Zhenhua

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

  19. A magnetic resonance spectroscopy driven initialization scheme for active shape model based prostate segmentation.

    Science.gov (United States)

    Toth, Robert; Tiwari, Pallavi; Rosen, Mark; Reed, Galen; Kurhanewicz, John; Kalyanpur, Arjun; Pungavkar, Sona; Madabhushi, Anant

    2011-04-01

    Segmentation of the prostate boundary on clinical images is useful in a large number of applications including calculation of prostate volume pre- and post-treatment, to detect extra-capsular spread, and for creating patient-specific anatomical models. Manual segmentation of the prostate boundary is, however, time consuming and subject to inter- and intra-reader variability. T2-weighted (T2-w) magnetic resonance (MR) structural imaging (MRI) and MR spectroscopy (MRS) have recently emerged as promising modalities for detection of prostate cancer in vivo. MRS data consists of spectral signals measuring relative metabolic concentrations, and the metavoxels near the prostate have distinct spectral signals from metavoxels outside the prostate. Active Shape Models (ASM's) have become very popular segmentation methods for biomedical imagery. However, ASMs require careful initialization and are extremely sensitive to model initialization. The primary contribution of this paper is a scheme to automatically initialize an ASM for prostate segmentation on endorectal in vivo multi-protocol MRI via automated identification of MR spectra that lie within the prostate. A replicated clustering scheme is employed to distinguish prostatic from extra-prostatic MR spectra in the midgland. The spatial locations of the prostate spectra so identified are used as the initial ROI for a 2D ASM. The midgland initializations are used to define a ROI that is then scaled in 3D to cover the base and apex of the prostate. A multi-feature ASM employing statistical texture features is then used to drive the edge detection instead of just image intensity information alone. Quantitative comparison with another recent ASM initialization method by Cosio showed that our scheme resulted in a superior average segmentation performance on a total of 388 2D MRI sections obtained from 32 3D endorectal in vivo patient studies. Initialization of a 2D ASM via our MRS-based clustering scheme resulted in an average

  20. Enhancing Educational Research and Development Activity through Small Grant Schemes: A Case Study

    Science.gov (United States)

    Morris, Clare; Fry, Heather

    2006-01-01

    There are many funding schemes in existence for small projects in educational development, but fewer equivalent research schemes. Data from an evaluation of two schemes at one institution are used as the catalyst for considering such schemes in wider contextual and theoretical perspectives. The evaluation analysed success rate data, project…

  1. Novel active fault-tolerant control scheme and its application to a double inverted pendulum system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    On the basis of the gain-scheduled H∞ design strategy,a novel active fault-tolerant control scheme is proposed.Under the assumption that the effects of faults on the state-space matrices of systems can be of affine parameter dependence,a reconfigurable robust H∞ linear parameter varying controller is developed.The designed controller is a function of the fault effect factors that can be derived online by using a well-trained neural network.To demonstrate the effectiveness of the proposed method,a double inverted pendulum system,with a fault in the motor tachometer loop,is considered.

  2. Effect of gamma-irradiation on frozen shrimps for inactivation of microorganisms and shelf-life extension under defrosted

    International Nuclear Information System (INIS)

    The effect of gamma-irradiation on inactivation of microorganisms in frozen shrimps was investigated for improving the hygienic quality and shelf-life after defrosted. Count of total aerobic bacteria in three different kinds of frozen shrimps were decreased below 104 per gram at 4 kGy of irradiation, and showed the similar pattern of inactivation curves under the same frozen condition . Coliforms were eliminated below 4 kGy of irradiation. Radiation-resistance of aerobic bacteria in frozen condition was larger than defrosted condition, and the necessary dose for inactivation of aerobic bacteria below the count of 104 per gram was required 3 kGy at defrosted condition, and 4 kGy at frozen condition. However, freezing could remarkably reduce the production of radiation induced off-odor from shrimps. Trimethylamine content in frozen shrimps did not get effect up to 50 kGy irradiation. Vibrio parahaemolyticus was isolated from 1 to 3 numbers in 100g of frozen shrimps, and necessary dose for elimination was decided as 1.5 to 2.0 kGy in frozen shrimps. Shelf-life of irradiated shrimps at 3 and 5 kGy was found to be 6 days at the storage condition of 5degC, whereas the unirradiated samples were putrefied below 3 days of storage. (author)

  3. Formation scheme and antioxidant activity of a novel Maillard pigment, pyrrolothiazolate, formed from cysteine and glucose.

    Science.gov (United States)

    Noda, Kyoko; Terasawa, Naoko; Murata, Masatsune

    2016-06-15

    We recently identified 6-hydroxy-3[R],7a[S]-dimethyl-7-oxo-2,3-dihydropyrrolo[2,1-b]thiazole-3-calboxylic acid, a novel pyrrolothiazole derivative carrying a carboxy group and named pyrrolothiazolate, as a Mallard pigment formed from l-cysteine and d-glucose. Here we described the formation of its enantiomer, the plausible formation scheme of pyrrolothiazolate, and its antioxidant activity. When d-cysteine was used instead of l-cysteine in the reaction mixture, the enantiomer of pyrrolothiazolate was obtained. The carbon at position 1 of glucose was incorporated into two methyl groups of pyrrolothiazolate. The pigment was considered to be formed through 1-deoxyglucosone (1-DG). The dehydrated isomer of 1-DG would be condensed with the thiol and amino groups of cysteine. This condensate was dehydrated and cyclized to form pyrrolothiazolate. This compound was an antioxidant showing radical scavenging activity. PMID:26987433

  4. A New Decoding Scheme for Errorless Codes for Overloaded CDMA with Active User Detection

    CERN Document Server

    Mousavi, Ali; Marvasti, Farokh

    2010-01-01

    Recently, a new class of binary codes for overloaded CDMA systems are proposed that not only has the ability of errorless communication but also suitable for detecting active users. These codes are called COWDA [1]. In [1], a Maximum Likelihood (ML) decoder is proposed for this class of codes. Although the proposed scheme of coding/decoding show impressive performance, the decoder can be improved. In this paper by assuming more practical conditions for the traffic in the system, we suggest an algorithm that increases the performance of the decoder several orders of magnitude (the Bit-Error-Rate (BER) is divided by a factor of 400 in some Eb/N0's The algorithm supposes the Poison distribution for the time of activation/deactivation of the users.

  5. Performance Analysis Of Active Queue Management AQM In VOIP Using Different Voice Encoder Scheme

    Directory of Open Access Journals (Sweden)

    Samir Eid Mohammed

    2015-08-01

    Full Text Available Abstract Voice over Internet Protocol VoIP is a rapidly growing technology that enables transport of voice over data networks such as Ethernet Wide area networks WANs due to this important different codec scheme is developed to meet the QoS requirements. This thesis presents a comprehensive study about the impact of active queue management AQM on Voice over Internet Protocol VoIP quality of service using different codec scheme such as G711 G723 G729 and GSM using simulations tools. The evaluation is done using the OPNET Modeler which provides a convenient and easy-to-use platform for simulating large scale networks and this also give a power to go through different levels of designing a network even with the ability to program the mechanism you want which is used here to implement two types of AQM mechanism which is not included by default in the OPNET and these two mechanisms are ARED and GRED. The performance metrics used in the study are jitter throughput and delay. The study shows that G.711 and G729 codecs in a simulation gives a significant result for the performance of VoIP that codec G711 and G.729A has acceptable throughput and less deviation of received to transmit packet as compared to GSM and G.723 also average delay like end to end delay and Voice jitter is lesser in codec G711 and G.729 as compared to the other two referenced codecs.

  6. Defrosting the digital library: bibliographic tools for the next generation web.

    Directory of Open Access Journals (Sweden)

    Duncan Hull

    2008-10-01

    Full Text Available Many scientists now manage the bulk of their bibliographic information electronically, thereby organizing their publications and citation material from digital libraries. However, a library has been described as "thought in cold storage," and unfortunately many digital libraries can be cold, impersonal, isolated, and inaccessible places. In this Review, we discuss the current chilly state of digital libraries for the computational biologist, including PubMed, IEEE Xplore, the ACM digital library, ISI Web of Knowledge, Scopus, Citeseer, arXiv, DBLP, and Google Scholar. We illustrate the current process of using these libraries with a typical workflow, and highlight problems with managing data and metadata using URIs. We then examine a range of new applications such as Zotero, Mendeley, Mekentosj Papers, MyNCBI, CiteULike, Connotea, and HubMed that exploit the Web to make these digital libraries more personal, sociable, integrated, and accessible places. We conclude with how these applications may begin to help achieve a digital defrost, and discuss some of the issues that will help or hinder this in terms of making libraries on the Web warmer places in the future, becoming resources that are considerably more useful to both humans and machines.

  7. Defrosting the digital library: bibliographic tools for the next generation web.

    Science.gov (United States)

    Hull, Duncan; Pettifer, Steve R; Kell, Douglas B

    2008-10-01

    Many scientists now manage the bulk of their bibliographic information electronically, thereby organizing their publications and citation material from digital libraries. However, a library has been described as "thought in cold storage," and unfortunately many digital libraries can be cold, impersonal, isolated, and inaccessible places. In this Review, we discuss the current chilly state of digital libraries for the computational biologist, including PubMed, IEEE Xplore, the ACM digital library, ISI Web of Knowledge, Scopus, Citeseer, arXiv, DBLP, and Google Scholar. We illustrate the current process of using these libraries with a typical workflow, and highlight problems with managing data and metadata using URIs. We then examine a range of new applications such as Zotero, Mendeley, Mekentosj Papers, MyNCBI, CiteULike, Connotea, and HubMed that exploit the Web to make these digital libraries more personal, sociable, integrated, and accessible places. We conclude with how these applications may begin to help achieve a digital defrost, and discuss some of the issues that will help or hinder this in terms of making libraries on the Web warmer places in the future, becoming resources that are considerably more useful to both humans and machines.

  8. The destructive negative binomial cure rate model with a latent activation scheme.

    Science.gov (United States)

    Cancho, Vicente G; Bandyopadhyay, Dipankar; Louzada, Francisco; Yiqi, Bao

    2013-07-01

    A new flexible cure rate survival model is developed where the initial number of competing causes of the event of interest (say lesions or altered cells) follow a compound negative binomial (NB) distribution. This model provides a realistic interpretation of the biological mechanism of the event of interest as it models a destructive process of the initial competing risk factors and records only the damaged portion of the original number of risk factors. Besides, it also accounts for the underlying mechanisms that leads to cure through various latent activation schemes. Our method of estimation exploits maximum likelihood (ML) tools. The methodology is illustrated on a real data set on malignant melanoma, and the finite sample behavior of parameter estimates are explored through simulation studies.

  9. Half-Duplex Active Eavesdropping in Fast Fading Channels: A Block-Markov Wyner Secrecy Encoding Scheme

    CERN Document Server

    Amariucai, George T

    2010-01-01

    In this paper we study the problem of half-duplex active eavesdropping in fast fading channels. The active eavesdropper is a more powerful adversary than the classical eavesdropper. It can choose between two functional modes: eavesdropping the transmission between the legitimate parties (Ex mode), and jamming it (Jx mode) -- the active eavesdropper cannot function in full duplex mode. We consider a conservative scenario, when the active eavesdropper can choose its strategy based on the legitimate transmitter-receiver pair's strategy -- and thus the transmitter and legitimate receiver have to plan for the worst. We show that conventional physical-layer secrecy approaches perform poorly (if at all), and we introduce a novel encoding scheme, based on very limited and unsecured feedback -- the Block-Markov Wyner (BMW) encoding scheme -- which outperforms any schemes currently available.

  10. Developing a Coding Scheme to Analyse Creativity in Highly-constrained Design Activities

    DEFF Research Database (Denmark)

    Dekoninck, Elies; Yue, Huang; Howard, Thomas J.;

    2010-01-01

    This work is part of a larger project which aims to investigate the nature of creativity and the effectiveness of creativity tools in highly-constrained design tasks. This paper presents the research where a coding scheme was developed and tested with a designer-researcher who conducted two rounds...... of design and analysis on a highly constrained design task. This paper shows how design changes can be coded using a scheme based on creative ‘modes of change’. The coding scheme can show the way a designer moves around the design space, and particularly the strategies that are used by a creative designer...... to skip from one ‘train of solutions’ to new avenues. The coding scheme can be made more robust by: ensuring design change is always coded relative to a reference design; tightening up definitions of ‘system’, ‘element’ and ‘function’; and using a matrix to develop a more complete set of codes. A much...

  11. An active 3-dimensional localization scheme for femtocell subscribers using E-UTRAN

    KAUST Repository

    Mohammed, Aquil Mirza

    2012-05-01

    Femtocells provide an efficient solution to overcome the indoor coverage problems and also to deal with the traffic within Macro cells. The possibility of localizing femtocell subscriber stations based on the timing ranging advance parameter (TRAP), obtained from E-UTRAN (Evolved UMTS Terrestrial Radio Access Network), within the network signal internals is challenging and is studied throughout in this paper. The principle approach to localization based on Euclidean distances from multiple base stations is outlined.We investigate the specifications of the timing parameters or TRAP used for air interface of 4G network as they relate to calculating the subscriber distances. Computer simulation is used to demonstrate the localization accuracy using multiple base station networks when estimating likely locations of femtocell subscribers stations on a twodimensional coordinate mapping system. However, we further extend our simulations to demonstrate expected location accuracy of subscriber stations, for multiple base station networks, on a three dimensional coordinate mapping scheme. The possibility of of error-fixes shows eight times greater accuracy than in previous results is expected to achieve by applying timing advance techniques to Global System for Mobile communications networks, by using a two-dimensional coordinate mapping scheme. We later compare our study with the effect of global positioning system (GPS) by using a three-dimensional coordinate mapping scheme, which is predicted to give an 72.4 cms accuracy of subscriber station location. © 2012 IEEE.

  12. Is MGNREG Scheme complementary to fishing activities? A study on some selected states of India

    Directory of Open Access Journals (Sweden)

    Chiranjib Neogi

    2016-01-01

    Full Text Available Freshwater fish output is taken as a proxy variable for empirical assessment of indirect benefits in terms of enhanced quantity of freshwater fish (output cultivation. It is not unlikely to assess empirically the productivity of subsidized public scheme when rural development or rural asset generations are underlined in the said scheme, MGNREG Act, 2005. Rainwater harvesting is a major component part of the scheme since about 49.5 per cent of the total fund is already utilized on water conservation and obviously it has an impact on the cultivation of freshwater fish output. Time series data on annual expenditure on MGNREG and corresponding freshwater fish output at the state level are taken during the period 2006-07 to 2013-14 for 16 major Indian states. Fixed effect model and random effect models are being applied and the Hausman specification test suggests that fixed effect model is more appropriate than random effect model. Significant differences among the intercepts of the selected states are revealed as per F test. The results of fixed effect panel regression establish that fish output is enhanced by 0.000257 thousand tones or 0.26 tones if MGNREG expenditure rises by one crore or 10 million rupees.

  13. A Repetitive Control Scheme Aimed at Compensating the 6k + 1 Harmonics for a Three-Phase Hybrid Active Filter

    DEFF Research Database (Denmark)

    Luo, Zhaoxu; Su, Mei; Yang, Jian;

    2016-01-01

    is reduced, and the possibility of amplifying and even injecting any harmonic noises into the system is avoided to a great extent. Moreover, the proposed repetitive scheme is used in the control of a three-phase hybrid active power filter. The experimental results validate the effectiveness of the proposed......The traditional repetitive controller has relatively worse stability and poor transient performance because it generates infinite gain at all the integer multiples of the fundamental frequency, and its control action is postponed by one fundamental period (T0). To improve these disadvantages, many...... repetitive controllers with reduced delay time have been proposed, which can selectively compensate the odd harmonics or 6k ± 1 harmonics with delay time reduced to T0/2 and T0/3, respectively. To further study in this area, this paper proposes an improved repetitive scheme implemented in a stationary...

  14. An experimental study on the negative effects of downwards flow of the melted frost over a multi-circuit outdoor coil in an air source heat pump during reverse cycle defrosting

    International Nuclear Information System (INIS)

    Highlights: • A special experimental rig was built and its details are reported. • The negative effects of downwards flowing of the melted frost were shown. • Defrosting duration was shortened after installing water collecting trays. • Temperature of melted frost decreased after installing trays. - Abstract: When the surface temperature of the outdoor coil in an air source heat pump (ASHP) unit is lower than both freezing point of water and the air dew point, frost can be formed and accumulated over outdoor coil surface. Frosting affects the energy efficiency, and periodic defrosting therefore is necessary. Reverse cycle defrosting is currently the most widely used defrosting method. A previous related study has indicated that during reverse cycle defrosting, downwards flow of the melted frost over a multi-circuit outdoor coil could affect the defrosting performance, without however giving detailed quantitative analysis of the effects. Therefore an experimental study on the effects has been carried out and a quantitative analysis conducted using the experimental data. In this paper, the detailed description of an experimental ASHP unit which was specifically built up is firstly reported. This is followed by presenting experimental results. Result analysis and conclusions are finally given

  15. A repetitive control scheme aiming to compensate the 6k+1 harmonics for three-phase hybrid active filter

    DEFF Research Database (Denmark)

    Luo, Zhaoxu; Su, Mei; Yang, Jian;

    2016-01-01

    in stationary reference frame, which only compensates the 6k+1 harmonics (e.g. -5, +7, -11, +13) in three-phase systems and reduces the time delay to T0/6 . So compared with the earlier reduced delay time repetitive controllers, the robustness and transient performance is further improved, the waste of control...... effort is reduced, and the possibility of amplifying and even injecting any harmonic noises into system is avoided to the greatest extent. Moreover, the proposed repetitive scheme is used in the control of a three-phase hybrid active power filter. The experimental results validate the effectiveness...

  16. Experimental study of an air-source heat pump for simultaneous heating and cooling - Part 2: Dynamic behaviour and two-phase thermosiphon defrosting technique

    International Nuclear Information System (INIS)

    Highlights: → Experimental study of an air-source heat pump for simultaneous heating and cooling. → Operating sequences alternating between heating, cooling and simultaneous modes. → Validation of the high pressure control system. → Validation of the non-penalizing two-phase thermosiphon defrosting sequence. - Abstract: This article presents the concepts of an air-source heat pump for simultaneous heating and cooling (HPS) designed for hotels and smaller residential, commercial and office buildings in which simultaneous needs in heating and cooling are frequent. The main advantage of the HPS is to carry out simultaneously space heating and space cooling with the same energy input. Ambient air is used as a balancing source to run a heating or a cooling mode. The second advantage is that, during winter, energy recovered by the subcooling of the refrigerant is stored at first in a water tank and used subsequently as a cold source at the water evaporator to improve the average performance and to carry out defrosting of the air evaporator using a two-phase thermosiphon. Unlike conventional air-source heat pumps, defrosting is carried out without stopping the heat production. A R407C HPS prototype was built and tested. The basic concepts of the HPS are detailed in part1 of this article . Its performance on defined operating conditions corresponds to the data given by the selection software of the compressor manufacturer. In the present part of this article, the operation of the high pressure control system, the transitions between heating, cooling and simultaneous modes and the defrosting sequence are analysed and validated experimentally.

  17. Active control for drag reduction in turbulent channel flow: the opposition control schemes revisited

    Science.gov (United States)

    Wang, Yin-Shan; Huang, Wei-Xi; Xu, Chun-Xiao

    2016-10-01

    The opposition control schemes first proposed by Choi et al (1994 J. Fluid Mech. 262 75) employing wall-normal (v) and spanwise (w) velocity are revisited in the present study by performing direct numerical simulation to turbulent channel flow at R{e}τ = 180. Special attention is paid to the combined control, in which the wall-normal and spanwise velocities are imposed at the wall just instantaneously opposite to those at a small distance to the wall. In comparison to the v- and w-controls, combined-control could achieve the best drag reduction rate and control efficiency, with the greatest suppression of turbulence intensities. The influence of control on the statistical properties of vortices is scrutinized. By control, the numbers of vortices with every circulation and radius apparently decrease at the same normal location near the wall, while the vortex radius scaled by the actual wall-friction velocity almost remains the same. The streamwise vortices and the induced Reynolds shear stress undergo the greatest suppression by combined control. It is shown that combined control achieves a better efficacy, attributed to the co-work of the mechanisms of the v- and w-controls. At a higher Reynolds number R{e}τ = 1000, combined control is also more effective than v- and w-controls. The better suppression effect on the outer large scales is the primary reason for the larger drag reduction rate in combined control.

  18. Source Driver Channel Reduction Schemes Employing Corresponding Pixel Alignments for Current Programming Active-Matrix Organic Light-Emitting Diode Displays

    Science.gov (United States)

    Hong, Soon-Kwang; Oh, Du-Hwan; Jeong, Seok-Hee; Park, Young-Ju; Kim, Byeong-Koo; Ha, Yong-Min; Jang, Jin

    2008-03-01

    We propose two types of novel scheme for reducing the number of output channels of driver-integrated circuit (D-IC) for the current programming compensation pixel structures of active-matrix organic light-emitting diodes (AMOLEDs). One is a 2:1 data demultiplexing technique that can reduce the number of output channels of D-IC by half. The proposed second scheme is a vertically aligned red (R), green (G), and blue (B) subpixel scheme instead of a horizontally aligned R-G-B subpixel one, which is regarded as the conventional pixel alignment scheme. We have also successfully implemented these schemes in a 2.4-in.-sized QCIF + (176 × RGB × 220) AMOLED using p-type excimer laser annealing (ELA) low-temperature polycrystalline silicon (LTPS) technology and evaluated key performance characteristics.

  19. Robust and fast schemes in broadband active noise and vibration control

    NARCIS (Netherlands)

    Fraanje, Petrus Rufus

    2004-01-01

    This thesis presents robust and fast active control algorithms for the suppression of broadband noise and vibration disturbances. Noise disturbances, e.g., generated by engines in airplanes and cars or by air ow, can be reduced by means of passive or active methods.

  20. Integrated separation scheme for measuring a suite of fission and activation products from a fresh mixed fission and activation product sample

    International Nuclear Information System (INIS)

    Mixed fission and activation materials resulting from various nuclear processes and events contain a wide range of isotopes for analysis spanning almost the entire periodic table. This work describes the production of a complex synthetic sample containing fission products, activation products, and irradiated soil, and determines the percent chemical recovery of select isotopes through the integrated chemical separation scheme. Based on the results of this experiment, a complex synthetic sample can be prepared with low atom/fission ratios and isotopes of interest accurately and precisely measured following an integrated chemical separation method. (author)

  1. Oleate lipase activity in Gardnerella vaginalis and reconsideration of existing biotype schemes

    Directory of Open Access Journals (Sweden)

    Moncla Bernard J

    2009-04-01

    Full Text Available Abstract Background Gardnerella vaginalis is a facultative gram positive organism that requires subculture every 1–2 days to maintain viability. It has been linked with bacterial vaginosis (BV, a syndrome that has been associated with increased risk for preterm delivery, pelvic inflammatory disease and HIV acquisition. About 10% of the G. vaginalis isolates have been reported to produce sialidase, but there have not been any studies relating sialidase production and biotype. Sialidase activity is dramatically increased in the vaginal fluid of women with BV and bacterial sialidases have been shown to increase the infectivity of HIV in vitro. There are 8 different biotypes of G. vaginalis. Biotypes 1–4 produce lipase and were reported to be associated with BV and the association of these biotypes with BV is under dispute. Other studies have demonstrated that G. vaginalis biotype 1 can stimulate HIV-1 production. Because of the discrepancies in the literature we compared the methods used to biotype G. vaginalis and investigated the relationship of biotype and sialidase production. Results A new medium for maintenance of Gardnerella vaginalis which allows survival for longer than one week is described. Some isolates only grew well under anaerobic conditions. Sialidase producing isolates were observed in 5 of the 6 biotypes tested. Using 4-methylumbelliferyl-oleate to determine lipase activity, instead of egg yolk agar, resulted in erroneous biotypes and does not provide reliable results. Conclusion Previous studies associating G. vaginalis biotype with bacterial vaginosis were methodologically flawed, suggesting there is not an association of G. vaginalis biotypes and bacterial vaginosis. Sialidase activity was observed in 5 of the 8 biotypes.

  2. GPU-based Monte Carlo Dust Radiative Transfer Scheme Applied to Active Galactic Nuclei

    Science.gov (United States)

    Heymann, Frank; Siebenmorgen, Ralf

    2012-05-01

    A three-dimensional parallel Monte Carlo (MC) dust radiative transfer code is presented. To overcome the huge computing-time requirements of MC treatments, the computational power of vectorized hardware is used, utilizing either multi-core computer power or graphics processing units. The approach is a self-consistent way to solve the radiative transfer equation in arbitrary dust configurations. The code calculates the equilibrium temperatures of two populations of large grains and stochastic heated polycyclic aromatic hydrocarbons. Anisotropic scattering is treated applying the Heney-Greenstein phase function. The spectral energy distribution (SED) of the object is derived at low spatial resolution by a photon counting procedure and at high spatial resolution by a vectorized ray tracer. The latter allows computation of high signal-to-noise images of the objects at any frequencies and arbitrary viewing angles. We test the robustness of our approach against other radiative transfer codes. The SED and dust temperatures of one- and two-dimensional benchmarks are reproduced at high precision. The parallelization capability of various MC algorithms is analyzed and included in our treatment. We utilize the Lucy algorithm for the optical thin case where the Poisson noise is high, the iteration-free Bjorkman & Wood method to reduce the calculation time, and the Fleck & Canfield diffusion approximation for extreme optical thick cells. The code is applied to model the appearance of active galactic nuclei (AGNs) at optical and infrared wavelengths. The AGN torus is clumpy and includes fluffy composite grains of various sizes made up of silicates and carbon. The dependence of the SED on the number of clumps in the torus and the viewing angle is studied. The appearance of the 10 μm silicate features in absorption or emission is discussed. The SED of the radio-loud quasar 3C 249.1 is fit by the AGN model and a cirrus component to account for the far-infrared emission.

  3. Colour schemes

    DEFF Research Database (Denmark)

    van Leeuwen, Theo

    2013-01-01

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

  4. Immersion freezing of supermicron mineral dust particles: freezing results, testing different schemes for describing ice nucleation, and ice nucleation active site densities.

    Science.gov (United States)

    Wheeler, M J; Mason, R H; Steunenberg, K; Wagstaff, M; Chou, C; Bertram, A K

    2015-05-14

    Ice nucleation on mineral dust particles is known to be an important process in the atmosphere. To accurately implement ice nucleation on mineral dust particles in atmospheric simulations, a suitable theory or scheme is desirable to describe laboratory freezing data in atmospheric models. In the following, we investigated ice nucleation by supermicron mineral dust particles [kaolinite and Arizona Test Dust (ATD)] in the immersion mode. The median freezing temperature for ATD was measured to be approximately -30 °C compared with approximately -36 °C for kaolinite. The freezing results were then used to test four different schemes previously used to describe ice nucleation in atmospheric models. In terms of ability to fit the data (quantified by calculating the reduced chi-squared values), the following order was found for ATD (from best to worst): active site, pdf-α, deterministic, single-α. For kaolinite, the following order was found (from best to worst): active site, deterministic, pdf-α, single-α. The variation in the predicted median freezing temperature per decade change in the cooling rate for each of the schemes was also compared with experimental results from other studies. The deterministic model predicts the median freezing temperature to be independent of cooling rate, while experimental results show a weak dependence on cooling rate. The single-α, pdf-α, and active site schemes all agree with the experimental results within roughly a factor of 2. On the basis of our results and previous results where different schemes were tested, the active site scheme is recommended for describing the freezing of ATD and kaolinite particles. We also used our ice nucleation results to determine the ice nucleation active site (INAS) density for the supermicron dust particles tested. Using the data, we show that the INAS densities of supermicron kaolinite and ATD particles studied here are smaller than the INAS densities of submicron kaolinite and ATD particles

  5. Downstream Activities at the Felda Land Development Scheme: Analysis on Motivational Factors of Women’s Participation in Business Activities

    OpenAIRE

    N.A.H. Idris; N.H.M. Salleh; W. Endut

    2014-01-01

    Federal Land Development Authority (FELDA) in Malaysia has been a successful land development agency for the past fifty-two years. Established on 1 July 1956, it is the main government instrument in reducing rural poverty in the Federation of Malaya. FELDA itself has grown into a conglomerate with numerous subsidiaries and joint-venture companies engaged in a variety of related upstream and downstream business. This paper deals with women’s participation in downstream activities. It provides ...

  6. Inspection scheme

    International Nuclear Information System (INIS)

    As part of the Danish RERTR Program, three fuel elements with LEU U3O8-Al fuel and three fuel elements with LEU U3Si2-Al fuel were manufactured by NUKEM for irradiation testing in the DR-3 reactor at the Risoe National Laboratory in Denmark. The inspection scheme for the elements with U3O8-Al fuel is presented here as an illustration only. The inspection scheme for the elements with U3Si2-Al fuel was very similar. In this example, all document numbers, drawing numbers, and form numbers have been deleted or replaced with a generic identification. (author)

  7. Health Professionals' Perspectives on Exercise Referral and Physical Activity Promotion in Primary Care: Findings from a Process Evaluation of the National Exercise Referral Scheme in Wales

    Science.gov (United States)

    Din, Nafees U.; Moore, Graham F.; Murphy, Simon; Wilkinson, Clare; Williams, Nefyn H.

    2015-01-01

    Background and objectives: Referring clinicians' experiences of exercise referral schemes (ERS) can provide valuable insights into their uptake. However, most qualitative studies focus on patient views only. This paper explores health professionals' perceptions of their role in promoting physical activity and experiences of a National Exercise…

  8. The Realization of a CO2 Heat Pump Defrosting Method%一种CO2热泵除霜方法的实现

    Institute of Scientific and Technical Information of China (English)

    杨军红

    2016-01-01

    空气源CO2热泵在冬季运行时,由于外部环境温度低、空气湿度大等原因,往往会在蒸发器表面形成霜层,从而降低热泵运行效率,甚至影响热泵机组的正常运行,根据CO2热泵的实际应用,设计一种CO2热泵智能除霜方法,用于解决空气源CO2热泵低温、高湿环境下的除霜问题。%Air source CO2 heat pump running in winter, due to the external environment of low temperature, high air humidity and so on, often formation frost layer in the evaporator surface, thereby reducing the efficiency of the heat pump, and even affect the normal operation of the heat pump units, this paper will according to the practical application of the CO2 heat pump, design a CO2 heat pump intelligent defrosting method, is used to solve the CO2 air source heat pump defrost problem under the low temperature, high humidity environment.

  9. MANIFESTATION OF THE EFFECT OF CRYOSELECTION IN CARP OFFSPRINGS OBTAINED FROM DEFROSTED SPERM SUSPENSION WITH MODIFIED CRYOPROTECTIVE SOLUTIONS

    Directory of Open Access Journals (Sweden)

    V. Cherepnin

    2016-09-01

    Full Text Available Purpose. The purpose of these studies was to evaluate the effect of the cryoselection of carp sperm of multiple age groups depending on the quality of thawed sperm after modification of the composite cryoprotective medium, which was used for the dilution of native sperm before freezing. Methodology. Coenzyme B12 (cobamamide, blood plasma of Prussian carp (Carassius gibelio, which was subjected to natural cold-acclimation, and purified protein antifreeze tmAFP isolated from larval mealworm (Tenebrio molitor, which also was subjected to natural cold-acclimation, were sued as modifiers. Findings. The results of the study demonstrated that qualitative and quantitative characteristics of the defrosted sperm, results of the incubation, rearing of embryos and larvae of Nyvky scaled carp (NLC, as well as fish culture parameters of produced young-of-the-year depended from on the composition of cryoprotective medium. The best results were demonstrated for the experimental groups, obtained with the use of the cryoprotective solution supplemented with purified antifreeze protein tmAFP. The larvae obtained from the sperm cryopreserved with the addition of cryoprotective medium TmAFP had better resistance to dehydration, surpassing the experimental groups obtained from the modifiers of Prussian carp plasma and cobamamide. There is a consolidation in the action of the related extracellular cryoprotectors, which were isolated from the cold-resistant organisms. And carp produced with their used demonstrated better performance during their rearing. The fact can be established that the manifestation of cryoselective effect depends on the integrity of sperm hereditary material and does not depend on the effect of extremely low temperatures on the cell membranes. Originality. There were the first experiments, where Prussian carp plasma and antifreeze protein tmAFP were used as extracellular cryoprotectors. Practical value. The modifications of composite

  10. Tabled Execution in Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Willcock, J J; Lumsdaine, A; Quinlan, D J

    2008-08-19

    Tabled execution is a generalization of memorization developed by the logic programming community. It not only saves results from tabled predicates, but also stores the set of currently active calls to them; tabled execution can thus provide meaningful semantics for programs that seemingly contain infinite recursions with the same arguments. In logic programming, tabled execution is used for many purposes, both for improving the efficiency of programs, and making tasks simpler and more direct to express than with normal logic programs. However, tabled execution is only infrequently applied in mainstream functional languages such as Scheme. We demonstrate an elegant implementation of tabled execution in Scheme, using a mix of continuation-passing style and mutable data. We also show the use of tabled execution in Scheme for a problem in formal language and automata theory, demonstrating that tabled execution can be a valuable tool for Scheme users.

  11. Development and experiment about recombination heating circulation defrosting system of mini cold storage house%微型冷库复合加热循环除霜系统的研制与试验

    Institute of Scientific and Technical Information of China (English)

    赵松松; 杨昭; 陈爱强; 张娜; 陈明锋; 刘兴华

    2015-01-01

    针对冷冻冷藏库传统除霜方法高能耗、冷库温湿度波动大等缺陷,通过设计系统除霜结构,完善控制策略,研发了一种智能除霜方法。复合加热循环除霜采用时间—压差联合智能控制策略界定最佳除霜点,配备排管辅助制冷技术,基于欧姆龙PLC高精度控制系统使各设备协同完成除霜过程。对复合加热循环除霜系统进行试验研究,对比分析不同除霜方法的工作性能及能耗情况。结果显示:相比于传统电加热除霜,复合加热循环除霜过程冷库温度波动减小3.8℃,相对湿度波动降低21.1百分点,除霜时间缩短14 min,系统除霜节能率达34.5%。%In recent years, mini cold storage house has developed rapidly. The evaporator is extremely easy to frost as a result of locating in the condition of low temperature and high humidity. However, defrosting energy consumption accounts for more than 10% of system’s total energy consumption. To overcome the defect about high energy consumption, temperature and humidity fluctuation of traditional defrosting technology in mini cold storage house, we investigated a new framework by changing the structure of the defrosting system and optimizing the control technology. Firstly, we developed a new defrosting system named as recombination heating circulation defrosting (RHCD) based on overhead coil auxiliary refrigeration. After that, the time-differential pressure (TDP) combining intelligent control method was used innovatively to determine the best defrosting point. Finally, OMRON programmable logic controller was applied to combine some devices to finish the defrosting. In the defrosting process, the electric-air valves installed on the incubator were closed timely to restrain heat and vapor into the cold storage house, and hot air flow was forced to circulate in the bypass channel under the working of blowers. Meanwhile overhead coil auxiliary refrigeration system was

  12. Supporting Innovation Activities of SMEs with Innovation Vouchers Scheme%英国实施创新券计划支持中小企业创新

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      英国技术战略委员会(TSB)最新推出创新券计划(Innovation Vouchers Scheme),专门支持中小企业创新活动。作为英国政府推出新的创新资助工具之一,该计划资助对象明确、资助目标清晰,资助重点突出,并且在资助方式上跟以往科技计划比较有所创新。通过对TSB推出的创新券计划资助标准和原则、资助领域和重点以及申请和资助流程进行详细介绍和分析,简要总结出创新券计划的几个特点,以为我国有关科技计划和创新基金实施提供参考。%The Innovation Vouchers Scheme was launched by Technology Strategy Board (TSB) of UK in 2012 as a new funding tool to support the innovation activities of SMEs specifically. The objects and priorities of Innovation Vouchers Scheme are clearly defined and the funding mode of the scheme has a big difference from other S&T programs. This paper introduced the funding standards and principles of the scheme, analyzed its funding priorities and application procedure, and summarized the new characteristics of Innovation Vouchers Scheme, hoping to provide a useful reference for the policy making and implement of innovation plan and programs in China.

  13. Nonstandard finite difference schemes

    Science.gov (United States)

    Mickens, Ronald E.

    1995-01-01

    The major research activities of this proposal center on the construction and analysis of nonstandard finite-difference schemes for ordinary and partial differential equations. In particular, we investigate schemes that either have zero truncation errors (exact schemes) or possess other significant features of importance for numerical integration. Our eventual goal is to bring these methods to bear on problems that arise in the modeling of various physical, engineering, and technological systems. At present, these efforts are extended in the direction of understanding the exact nature of these nonstandard procedures and extending their use to more complicated model equations. Our presentation will give a listing (obtained to date) of the nonstandard rules, their application to a number of linear and nonlinear, ordinary and partial differential equations. In certain cases, numerical results will be presented.

  14. New Driving Scheme to Improve Hysteresis Characteristics of Organic Thin Film Transistor-Driven Active-Matrix Organic Light Emitting Diode Display

    Science.gov (United States)

    Yamamoto, Toshihiro; Nakajima, Yoshiki; Takei, Tatsuya; Fujisaki, Yoshihide; Fukagawa, Hirohiko; Suzuki, Mitsunori; Motomura, Genichi; Sato, Hiroto; Tokito, Shizuo; Fujikake, Hideo

    2011-02-01

    A new driving scheme for an active-matrix organic light emitting diode (AMOLED) display was developed to prevent the picture quality degradation caused by the hysteresis characteristics of organic thin film transistors (OTFTs). In this driving scheme, the gate electrode voltage of a driving-OTFT is directly controlled through the storage capacitor so that the operating point for the driving-OTFT is on the same hysteresis curve for every pixel after signal data are stored in the storage capacitor. Although the number of OTFTs in each pixel for the AMOLED display is restricted because OTFT size should be large enough to drive organic light emitting diodes (OLEDs) due to their small carrier mobility, it can improve the picture quality for an OTFT-driven flexible OLED display with the basic two transistor-one capacitor circuitry.

  15. Fabrication of Z-scheme Ag3PO4/MoS2 composites with enhanced photocatalytic activity and stability for organic pollutant degradation

    Science.gov (United States)

    Zhu, Chaosheng; Zhang, Lu; Jiang, Bo; Zheng, Jingtang; Hu, Ping; Li, Sujuan; Wu, Mingbo; Wu, Wenting

    2016-07-01

    In this study, highly efficient visible-light-driven Ag3PO4/MoS2 composite photocatalysts with different weight ratios of MoS2 were prepared via the ethanol-water mixed solvents precipitation method and characterized by ICP, XRD, HRTEM, FE-SEM, BET, XPS, UV-vis DRS and PL analysis. Under visible-light irradiation, Ag3PO4/MoS2 composites exhibit excellent photocatalytic activity towards the degradation of organic pollutants in aqueous solution. The optimal composite with 0.648 wt% MoS2 content exhibits the highest photocatalytic activity, which can degrade almost all MB under visible-light irradiation within 60 min. Recycling experiments confirmed that the Ag3PO4/MoS2 catalysts had superior cycle performance and stability. The photocatalytic activity enhancement of Ag3PO4/MoS2 photocatalysts can be mainly ascribed to the efficient separation of photogenerated charge carriers and the stronger oxidation and reduction ability through a Z-scheme system composed of Ag3PO4, Ag and MoS2, in which Ag particles act as the charge separation center. The high photocatalytic stability is due to the successful inhibition of the photocorrosion of Ag3PO4 by transferring the photogenerated electrons of Ag3PO4 to MoS2. The evidence of the Z-scheme photocatalytic mechanism of the composite photocatalysts could be obtained from the active species trapping experiments and the photoluminescence technique.

  16. In-situ preparation of Z-scheme AgI/Bi5O7I hybrid and its excellent photocatalytic activity

    Science.gov (United States)

    Cui, Min; Yu, Jingxiong; Lin, Hongjun; Wu, Ying; Zhao, Leihong; He, Yiming

    2016-11-01

    The aim of this work was to synthesize, characterize and evaluate the photocatalytic activity of AgI/Bi5O7I composite photocatalyst under visible light irradiation. The photocatalyst was prepared by a simple one-step ionic reaction between Bi5O7I microrods and AgNO3 solutions, and was characterized by various techniques including X-ray diffraction (XRD), Raman spectroscopy (Raman), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence spectroscopy (PL). The characterizations indicate that AgI particles were closely anchored on Bi5O7I micronods. During the photocataytic reaction, the composite was actually an Ag-AgI-Bi5O7I ternary system. The plasmonic effect of the formed Ag nanoparticles improved the visible light absorption performance, which benefits the photocatalytic reaction. However, more important was the formed heterojunction structure in the composite, which efficiently promoted the separation of electron-hole pairs by a plasmonic Z-scheme mechanism, and ultimately enhanced the photocatalytic activity. The optimal AgI/Bi5O7I composite showed a RhB degradation rate of 0.046 min-1, which was 3.83 and 6.57 times higher than those of Bi5O7I and AgI, respectively. This work may provide some insight into the design of novel and highly efficient Z-scheme visible-light photocatalysts.

  17. News Schemes for Activity Recognition Systems Using PCA-WSVM, ICA-WSVM, and LDA-WSVM

    Directory of Open Access Journals (Sweden)

    M’hamed Bilal Abidine

    2015-08-01

    Full Text Available Feature extraction and classification are two key steps for activity recognition in a smart home environment. In this work, we used three methods for feature extraction: Principal Component Analysis (PCA, Independent Component Analysis (ICA, and Linear Discriminant Analysis (LDA. The new features selected by each method are then used as the inputs for a Weighted Support Vector Machines (WSVM classifier. This classifier is used to handle the problem of imbalanced activity data from the sensor readings. The experiments were implemented on multiple real-world datasets with Conditional Random Fields (CRF, standard Support Vector Machines (SVM, Weighted SVM, and combined methods PCA+WSVM, ICA+WSVM, and LDA+WSVM showed that LDA+WSVM had a higher recognition rate than other methods for activity recognition.

  18. An Enhanced Droop Control Scheme for Resilient Active Power Sharing in Paralleled Two-Stage PV Inverter Systems

    DEFF Research Database (Denmark)

    Liu, Hongpeng; Yang, Yongheng; Wang, Xiongfei;

    2016-01-01

    generation) due to the intermittency. In that case, unbalance in active power generation may occur among the paralleled systems. Additionally, most droop-controlled systems have been assumed to be a single dc-ac inverter with a fixed dc input source. The dc-dc converter as the front-end of a two...

  19. Electromyographic activity of hand muscles in a motor coordination game: effect of incentive scheme and its relation with social capital.

    Directory of Open Access Journals (Sweden)

    Roberto Censolo

    Full Text Available BACKGROUND: A vast body of social and cognitive psychology studies in humans reports evidence that external rewards, typically monetary ones, undermine intrinsic motivation. These findings challenge the standard selfish-rationality assumption at the core of economic reasoning. In the present work we aimed at investigating whether the different modulation of a given monetary reward automatically and unconsciously affects effort and performance of participants involved in a game devoid of visual and verbal interaction and without any perspective-taking activity. METHODOLOGY/PRINCIPAL FINDINGS: Twelve pairs of participants were submitted to a simple motor coordination game while recording the electromyographic activity of First Dorsal Interosseus (FDI, the muscle mainly involved in the task. EMG data show a clear effect of alternative rewards strategies on subjects' motor behavior. Moreover, participants' stock of relevant past social experiences, measured by a specifically designed questionnaire, was significantly correlated with EMG activity, showing that only low social capital subjects responded to monetary incentives consistently with a standard rationality prediction. CONCLUSIONS/SIGNIFICANCE: Our findings show that the effect of extrinsic motivations on performance may arise outside social contexts involving complex cognitive processes due to conscious perspective-taking activity. More importantly, the peculiar performance of low social capital individuals, in agreement with standard economic reasoning, adds to the knowledge of the circumstances that makes the crowding out/in of intrinsic motivation likely to occur. This may help in improving the prediction and accuracy of economic models and reconcile this puzzling effect of external incentives with economic theory.

  20. National youth schemes in Malaysia: a survey.

    OpenAIRE

    Phan-Thuy, N

    1983-01-01

    ILO pub-WEP pub. Working paper on activities and training programmes of the national youth organization in Malaysia - discusses youth unemployment, youth scheme objectives (partic. Integration of rural youth in economic development and community development), institutional framework, activities (leadership development, vocational training, cooperatives, etc.), financing and training participation rate; includes a cost benefit analysis of four land settlement schemes and suggestions for youth ...

  1. Pixel-Level Digital-to-Analog Conversion Scheme with Compensation of Thin-Film-Transistor Variations for Compact Integrated Data Drivers of Active Matrix Organic Light Emitting Diodes

    Science.gov (United States)

    Kim, Tae-Wook; Park, Sang-Gyu; Choi, Byong-Deok

    2011-03-01

    The previous pixel-level digital-to-analog-conversion (DAC) scheme that implements a part of a DAC in a pixel circuit turned out to be very efficient for reducing the peripheral area of an integrated data driver fabricated with low-temperature polycrystalline silicon thin-film transistors (LTPS TFTs). However, how the pixel-level DAC can be compatible with the existing pixel circuits including compensation schemes of TFT variations and IR drops on supply rails, which is of primary importance for active matrix organic light emitting diodes (AMOLEDs) is an issue in this scheme, because LTPS TFTs suffer from random variations in their characteristics. In this paper, we show that the pixel-level DAC scheme can be successfully used with the previous compensation schemes by giving two examples of voltage- and current-programming pixels. The previous pixel-level DAC schemes require additional two TFTs and one capacitor, but for these newly proposed pixel circuits, the overhead is no more than two TFTs by utilizing the already existing capacitor. In addition, through a detailed analysis, it has been shown that the pixel-level DAC can be expanded to a 4-bit resolution, or be applied together with 1:2 demultiplexing driving for 6- to 8-in. diagonal XGA AMOLED display panels.

  2. 适用主动配电网的差动保护方案研究%Differential protection scheme to apply to active distribution network

    Institute of Scientific and Technical Information of China (English)

    李瑞生

    2015-01-01

    为了解决主动配电网双向潮流对电缆型配电网保护影响,分析了DER接入电缆型配电网对保护带来的问题,提出了适用于主动配电网的差动保护方案。差动保护方案配置集中式线路差动与就地式母线差动保护,适用于电缆线路的配电自动化。DTU 采用内置以太网通信技术,采用专用光纤通道“手拉手”连接。基于光纤通道实现DTU 数据同步,DTU 进出电流传输至集中式差动保护装置,由集中式差动保护装置实现配电网线路保护,DTU就地实现环网柜母线保护,能很好地满足电缆线路ADN接入DG对保护的要求。设计开发了相应的DTU及集中式差动保护装置,应用在实际的电缆线路ADN系统,具有很好的应用前景。%To solve the cable line distribution network protection impact of active distribution network bi-directional current, this paper analyzes the protection problem of the DER access and puts forward the scheme adapt to active distribution network differential protection. The scheme disposes centralized line differential protection and decentralized bus differential protection locally, which is suitable for cable line distribution automation. DTU adopts built-in Ethernet port technology, uses dedicated fiber channel hand in hand to connect. Based on fiber channel to realize synchronous sampling, DTU transfers current-in line and current-out line to centralized differential protection device, centralized differential protection device realizes distribution network line protection, DTU realizes ring main unit bus protection, which can well solve those problems of DG access. Corresponding DTU and centralized protection device are designed and used in the practical cable line ADN system, which has good application prospect.

  3. Finite Boltzmann schemes

    NARCIS (Netherlands)

    Sman, van der R.G.M.

    2006-01-01

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

  4. Scheme Program Documentation Tools

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2004-01-01

    This paper describes and discusses two different Scheme documentation tools. The first is SchemeDoc, which is intended for documentation of the interfaces of Scheme libraries (APIs). The second is the Scheme Elucidator, which is for internal documentation of Scheme programs. Although the tools...... are separate and intended for different documentation purposes they are related to each other in several ways. Both tools are based on XML languages for tool setup and for documentation authoring. In addition, both tools rely on the LAML framework which---in a systematic way---makes an XML language available...

  5. CSR schemes in agribusiness

    DEFF Research Database (Denmark)

    Pötz, Katharina Anna; Haas, Rainer; Balzarova, Michaela

    2013-01-01

    of schemes that can be categorized on focus areas, scales, mechanisms, origins, types and commitment levels. Research limitations/implications – The findings contribute to conceptual and empirical research on existing models to compare and analyse CSR standards. Sampling technique and depth of analysis limit...... this research, but the authors offer insights into patterns of CSR standard development in agribusiness and point to important research avenues. Practical implications – These findings can help agribusiness managers to select and analyse CSR standards and other forms of CSR guidance. Social implications...... – Standard and guidance setting activities can be expected to have real-life effects on CSR outcomes. These effects need to be better understood by policy makers and stakeholders. The authors' meta-analysis contributes to further research on who or what influences standard development. Originality...

  6. Convertible Proxy Signcryption Scheme

    Institute of Scientific and Technical Information of China (English)

    李继国; 李建中; 曹珍富; 张亦辰

    2004-01-01

    In 1996, Mambo et al introduced the concept of proxy signature. However, proxy signature can only provide the delegated authenticity and cannot provide confidentiality. Recently, Gamage et al and Chan and Wei proposed different proxy signcryption schemes respectively, which extended the concept of proxy signature.However, only the specified receiver can decrypt and verify the validity of proxy signcryption in their schemes.To protect the receiver' s benefit in case of a later dispute, Wu and Hsu proposed a convertible authenticated encryption scheme, which carn enable the receiver to convert signature into an ordinary one that can be verified by anyone. Based on Wu and Hsu' s scheme and improved Kim' s scheme, we propose a convertible proxy signcryption scheme. The security of the proposed scheme is based on the intractability of reversing the one-way hash function and solving the discrete logarithm problem. The proposed scheme can satisfy all properties of strong proxy signature and withstand the public key substitution attack and does not use secure channel. In addition, the proposed scheme can be extended to convertible threshold proxy signcryption scheme.

  7. Stateless Transitive Signature Schemes

    Institute of Scientific and Technical Information of China (English)

    MA Chun-guang; CAI Man-chun; YANG Yi-xian

    2004-01-01

    A new practical method is introduced to transform the stateful transitive signature scheme to stateless one without the loss of security. According to the approach, two concrete stateless transitive signature schemes based on Factoring and RSA are presented respectively. Under the assumption of the hardness of factoring and one-more- RSA-inversion problem, both two schemes are secure under the adaptive chosen-message attacks in random oracle model.

  8. Monitoring of the ground surface temperature and the active layer in NorthEastern Canadian permafrost areas using remote sensing data assimilated in a climate land surface scheme.

    Science.gov (United States)

    Marchand, N.; Royer, A.; Krinner, G.; Roy, A.

    2014-12-01

    Projected future warming is particularly strong in the Northern high latitudes where increases of temperatures are up to 2 to 6 °C. Permafrost is present on 25 % of the northern hemisphere lands and contain high quantities of « frozen » carbon, estimated at 1400 Gt (40 % of the global terrestrial carbon). The aim of this study is to improve our understanding of the climate evolution in arctic areas, and more specifically of land areas covered by snow. The objective is to describe the ground temperature year round including under snow cover, and to analyse the active layer thickness evolution in relation to the climate variability. We use satellite data (fusion of MODIS land surface temperature « LST » and microwave AMSR-E brightness temperature « Tb ») assimilated in the Canadian Land Surface Scheme (CLASS) of the Canadian climate model coupled with a simple radiative transfer model (HUT). This approach benefits from the advantages of each of the data type in order to complete two objectives : 1- build a solid methodology for retrieving the ground temperature, with and without snow cover, in taïga and tundra areas ; 2 - from those retrieved ground temperatures, derive the summer melt duration and the active layer depth. We describe the coupling of the models and the methodology that adjusts the meteorological input parameters of the CLASS model (mainly air temperature and precipitations derived from the NARR database) in order to minimise the simulated LST and Tb ouputs in comparison with satellite measurements. Using ground-based meteorological data as validation references in NorthEastern Canadian tundra, the results show that the proposed approach improves the soil temperatures estimates when using the MODIS LST and Tb at 10 and 19 GHz to constrain the model in comparison with the model outputs without satellite data. Error analysis is discussed for the summer period (2.5 - 4 K) and for the snow covered winter period (2 - 3.5 K). Further steps are

  9. Multiresolution signal decomposition schemes

    NARCIS (Netherlands)

    Goutsias, J.; Heijmans, H.J.A.M.

    1998-01-01

    [PNA-R9810] Interest in multiresolution techniques for signal processing and analysis is increasing steadily. An important instance of such a technique is the so-called pyramid decomposition scheme. This report proposes a general axiomatic pyramid decomposition scheme for signal analysis and synthes

  10. Succesful labelling schemes

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn; Stacey, Julia

    2001-01-01

    labelling schemes. Mass communication such as TV commercials will have very different impact on each of the four segments. It might be possible to increase the knowledge of 'the labelling blind' from 52% to 75%, but the use of the label would only rise from 16% to 18%. The awareness percentage of 'the...... to carry out a campaign targeted at this segment. The awareness percentage is already 92 % and 67% of the respondents believe they know the meaning of the scheme. But it stands to reason to study whether the respondents actually know what the labelling scheme stands for or if they just think they do....... If there is discrepancy between their perceptions of the contents of the schemes, this might be the reason why the scheme is not observed when they shop....

  11. AUTISTIC CHILDREN PROTECTION SCHEME

    Directory of Open Access Journals (Sweden)

    Dragan LUKIC

    1998-09-01

    Full Text Available The present article sets forth the theoretical grounds which make the basis for the organizational scheme of the autistic persons social protection. This protection consists of the below listed forms of work:· Health service with the role of an early detection and participation in the creation of rehabilitation programs;· Social protection with its programs of work from the diagnostics where the defectologist makes a team together with the physician and the psychologists to the systems of rehabilitation institutions where the defectologist’s is the main responsibility.The present article underlines two facts, namely:· that an autistic person requires to be followed and every spare moment used to promote and advance the activities the doer commenced himself instead of having him carry out the programs which are beyond his internal motivations and which he finds emotionally inaccessible;· that and form of work organization with autistic persons must subordinate its administrative part to the basic professional requirements this kind of disorder (handicap sets in front of each professional.

  12. Can adding web-based support to UK primary care exercise referral schemes improve patients’ physical activity levels? Findings from an internal pilot study.

    Directory of Open Access Journals (Sweden)

    Adrian Taylor

    2015-10-01

    Full Text Available Background: Promoting physical activity (PA via primary care exercise referral schemes (ERS is common but there is no rigorous evidence for long term changes in PA (Pavey et al, 2011 among those with chronic conditions. From July 2015, for 15 months, the e-coachER trial began to recruit 1400 patients (in SW England, Birmingham and Glasgow with one or more chronic conditions including diabetes, obesity, hypertension, osteoarthritis, or depression, who are eligible and about to attend an ERS. The two-arm parallel RCT is powered to determine if the addition of a web-based, interactive, theory-driven and evidence-based support system called e-coachER (hosted on the ‘LifeGuide’ platform will result in at least 10% more patients who do 150 mins or more per week of accelerometer assessed moderate or vigorous physical activity (MVPA at 12 months. Recruitment into the trial is within primary care, using both mail-merged patient invitations and opportunistic GP invitations (and exercise referrals. Within the trial, after participants are screened, provide consent and complete baseline assessments, they are randomised to receive usual ERS at each site or usual ERS plus a mailed Welcome Pack with registration details to access e-coachER on-line. Inclusion criteria for entering the trial are: (1 Aged 16-74 years; (2 with one or more of the following: obesity (BMI 30-35, hypertension (SBP 140-179 or DBP 90-109, type 2 diabetes, lower limb osteoarthritis, recent history of treatment for depression; (3 Participants who are in the two lowest (of four groups using the GP Physical Activity Questionnaire; (4 have an e-mail address and access to the internet; (5 Eligible for an ERS. The intervention rationale, design and content are reported in another presentation. Aims: This presentation will provide initial findings from a 3 month internal pilot phase with a focus on trial recruitment and initial intervention engagement. We will present data on the

  13. A Fuzzy Commitment Scheme

    CERN Document Server

    Al-saggaf, Alawi A

    2008-01-01

    This paper attempt has been made to explain a fuzzy commitment scheme. In the conventional Commitment schemes, both committed string m and valid opening key are required to enable the sender to prove the commitment. However there could be many instances where the transmission involves noise or minor errors arising purely because of the factors over which neither the sender nor the receiver have any control. The fuzzy commitment scheme presented in this paper is to accept the opening key that is close to the original one in suitable distance metric, but not necessarily identical. The concept itself is illustrated with the help of simple situation.

  14. Scheme of energy utilities

    International Nuclear Information System (INIS)

    This scheme defines the objectives relative to the renewable energies and the rational use of the energy in the framework of the national energy policy. It evaluates the needs and the potentialities of the regions and preconizes the actions between the government and the territorial organizations. The document is presented in four parts: the situation, the stakes and forecasts; the possible actions for new measures; the scheme management and the regional contributions analysis. (A.L.B.)

  15. Indirect visual cryptography scheme

    Science.gov (United States)

    Yang, Xiubo; Li, Tuo; Shi, Yishi

    2015-10-01

    Visual cryptography (VC), a new cryptographic scheme for image. Here in encryption, image with message is encoded to be N sub-images and any K sub-images can decode the message in a special rules (N>=2, 2images are printed on transparency and stacked exactly, the message of original image will be decrypted by human visual system, but any K-1 of them get no information about it. This cryptographic scheme can decode concealed images without any cryptographic computations, and it has high security. But this scheme lacks of hidden because of obvious feature of sub-images. In this paper, we introduce indirect visual cryptography scheme (IVCS), which encodes sub-images to be pure phase images without visible strength based on encoding of visual cryptography. The pure phase image is final ciphertexts. Indirect visual cryptography scheme not only inherits the merits of visual cryptography, but also raises indirection, hidden and security. Meanwhile, the accuracy alignment is not required any more, which leads to the strong anti-interference capacity and robust in this scheme. System of decryption can be integrated highly and operated conveniently, and its process of decryption is dynamic and fast, which all lead to the good potentials in practices.

  16. Secure Order-Specified Multisignature Scheme Based on DSA

    Institute of Scientific and Technical Information of China (English)

    YANG Muxiang; SU Li; LI Jun; HONG Fan

    2006-01-01

    In multisignature schemes signers can sign either in a linear order or not in any specified order, but neither of them is adequate in some scenarios where require mixture using of orderless and ordered multisignature. Most order-specified multisignatures specified the orders as linear ones. In this paper, we proposed an order-specified multisignature scheme based on DSA secure against active insider attack. To our knowledge, it is the first order-specified multisignature scheme based on DSA signature scheme, in which signers can sign in flexible order represented by series-parallel graphs. In the multisignature scheme verification to both signers and signing order are available. The security of the scheme is proved by reduce to an identification scheme that is proved have some concrete security. The running time of verifying a signature is comparable to previous schemes while the running time of multisignature generation and the space needed is less than those schemes.

  17. XTR-Kurosawa-Desmedt Scheme

    Institute of Scientific and Technical Information of China (English)

    DING XIU-HUAN; FU ZHI-GUO; ZHANG SHU-GONG

    2009-01-01

    This paper proposes an XTR version of the Kurosawa-Desmedt scheme. Our scheme is secure against adaptive choeen-ciphertext attack under the XTR version of the Decisional Diffie-Hellman assumption in the standard model. Comparing efficiency between the Kurosawa-Desmedt scheme and the proposed XTR-Kurosawa-Desmedt scheme, we find that the proposed scheme is more efficient than the Kurosawa-Desmedt scheme both in communication and computation without compromising security.

  18. Link Monotonic Allocation Schemes

    NARCIS (Netherlands)

    Slikker, M.

    1999-01-01

    A network is a graph where the nodes represent players and the links represent bilateral interaction between the players. A reward game assigns a value to every network on a fixed set of players. An allocation scheme specifies how to distribute the worth of every network among the players. This allo

  19. Alternative health insurance schemes

    DEFF Research Database (Denmark)

    Keiding, Hans; Hansen, Bodil O.

    2002-01-01

    In this paper, we present a simple model of health insurance with asymmetric information, where we compare two alternative ways of organizing the insurance market. Either as a competitive insurance market, where some risks remain uninsured, or as a compulsory scheme, where however, the level...... competitive insurance; this situation turns out to be at least as good as either of the alternatives...

  20. Enhanced arbitrated quantum signature scheme using Bell states

    Science.gov (United States)

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

    2014-06-01

    We investigate the existing arbitrated quantum signature schemes as well as their cryptanalysis, including intercept-resend attack and denial-of-service attack. By exploring the loopholes of these schemes, a malicious signatory may successfully disavow signed messages, or the receiver may actively negate the signature from the signatory without being detected. By modifying the existing schemes, we develop counter-measures to these attacks using Bell states. The newly proposed scheme puts forward the security of arbitrated quantum signature. Furthermore, several valuable topics are also presented for further research of the quantum signature scheme.

  1. On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme

    Directory of Open Access Journals (Sweden)

    Wang Daoshun

    2010-01-01

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

  2. The Picard Scheme

    OpenAIRE

    Kleiman, Steven L.

    2013-01-01

    We develop in detail most of the theory of the Picard scheme that Grothendieck sketched in two Bourbaki talks and in commentaries on them. Also, we review in brief much of the rest of the theory developed by Grothendieck and by others. But we begin with a twelve-page historical introduction, which traces the development of the ideas from Bernoulli to Grothendieck, and which may appeal to a wider audience.

  3. Fabrication and characterization of novel Z-scheme photocatalyst WO{sub 3}/g-C{sub 3}N{sub 4} with high efficient visible light photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shifu, E-mail: chshifu@chnu.edu.cn [Department of Chemistry, Anhui Science and Technology University, Anhui, Fengyang 233100 (China); Department of Chemistry, Huaibei Normal University, Anhui, Huaibei 235000 (China); Hu, Yingfei; Jiang, Xiaoliang; Meng, Sugang; Fu, Xianliang [Department of Chemistry, Huaibei Normal University, Anhui, Huaibei 235000 (China)

    2015-01-15

    Developing a high-efficiency visible light photocatalyst is always a research hotspot in photocatalytic field. In this study, a novel Z-scheme photocatalyst WO{sub 3}/g-C{sub 3}N{sub 4} with high efficient visible light photocatalytic activity was prepared via ball milling and heat treatment methods. The photocatalyst was characterized by X-ray powder diffraction (XRD), UV–vis diffuse reflection spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron spin resonance (ESR), and photoluminescence (PL). The photocatalytic activity was evaluated by degradation of methylene blue (MB) and fuchsin (BF) under visible light illumination. The results showed that composite WO{sub 3}/g-C{sub 3}N{sub 4} exhibits a much higher photocatalytic activity than a single g-C{sub 3}N{sub 4}. The rate constants of photocatalytic degradation of MB and BF for WO{sub 3}(5.0 wt.%)/g-C{sub 3}N{sub 4} are 4.77 times and 3.84 times that of pure g-C{sub 3}N{sub 4}. The characterization results by physical and chemical methods demonstrated that composite WO{sub 3}/g-C{sub 3}N{sub 4} is a typical Z-scheme photocatalyst. The enhancement of the photocatalytic activity may be attributed to the formation of the Z-scheme system between g-C{sub 3}N{sub 4} and WO{sub 3}, which could result in the photoexcited electrons of g-C{sub 3}N{sub 4} and photoexcited holes of WO{sub 3} participating in oxidation and reduction reactions, respectively. - Graphical abstract: When WO{sub 3} is combined with g-C{sub 3}N{sub 4}, a Z-scheme system photocatalyst may be formed because of the short distance between the VB of g-C{sub 3}N{sub 4} and the CB of WO{sub 3}. Consequently, the photogenerated electrons in the CB of g-C{sub 3}N{sub 4} and holes in the VB of WO{sub 3} exhibit excellent reduction and oxidation ability, respectively. - Highlights: • WO{sub 3}/g-C{sub 3}N{sub 4} photocatalyst with high efficient visible light activity was prepared. • The WO{sub 3}/g

  4. Development of a nitrogen-cooled cryoprobe with non-electric defrosting for use in corporeal cavities; Entwicklung einer stickstoffgekuehlten Kryosonde mit nicht-elektrischer Abtauung fuer den Einsatz in Koerperhoehlen

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, B. [Inst. fuer Luft- und Kaeltetechnik GmbH, Dresden (Germany); Herzog, R. [Inst. fuer Luft- und Kaeltetechnik GmbH, Dresden (Germany); Krantz, H. [Medizinische Akademie Dresden (Germany); Spoerl, E. [Medizinische Akademie Dresden (Germany)

    1994-12-31

    Cryotherapy has been used succesfully for about 20 years in the treatment of benign and malignant neoplasms of the skin or mucous membranes. A problematic circumstance is that cryoprobes applied while still body-warm induce formation of large ice crystals during the cooling process. To evade the adhesive forces developed by these crystals the probe must be defrosted at the end of the procedure. Cryoprobes for use in corporeal cavities must therefore be designed to specific technical requirements. This paper presents target specifications for the new development of a gynaecological cryoprobe. In this connection it explains the thermodynamic principle of function, its constructional realisation, and the technical concept employed for the design of a cryoprobe. (BWI) [Deutsch] Die Kryotherapie wird seit etwa 20 Jahren mit Erfolg zur Behandlung von gut- und boesartigen Neubildungen der Haut und der Schleimhaut eingesetzt. Bei koerperwarm aufgesetzten Kryosoden bilden sich allerdings waehrend des Abkuehlprozesses groessere Eiskristalle heraus, die Haftkraefte ausloesen, so dass die Sonde nach Therapieende abgetaut werden muss. Bei der Anwendung von Kryosonden in Koerperhoehlen ergeben sich deshalb besondere technische Forderungen. Der vorliegende Beitrag stellt die Zielstellung fuer die Neuentwicklung einer gynaekologischen Kryosonde vor. In diesem Zusammenhang wird auf das thermodynamische Funktionsprinzip sowie die konstruktive Umsetzung und das geraetetechnische Konzept eingegangen. (BWI)

  5. A PRACTICAL PROXY SIGNATURE SCHEME

    Directory of Open Access Journals (Sweden)

    Sattar Aboud

    2012-01-01

    Full Text Available A proxy signature scheme is a variation of the ordinary digital signature scheme which enables a proxy signer to generate signatures on behalf of an original signer. In this paper, we present two efficient types of proxy signature scheme. The first one is the proxy signature for warrant partial delegation combines an advantage of two well known warrant partial delegation schemes. This proposed proxy signature scheme is based on the difficulty of solving the discrete logarithm problem. The second proposed scheme is based on threshold delegation the proxy signer power to sign the message is share. We claim that the proposed proxy signature schemes meet the security requirements and more practical than the existing proxy signature schemes.

  6. Two Improved Digital Signature Schemes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, two improved digital signature schemes are presented based on the design of directed signaturescheme [3]. The peculiarity of the system is that only if the scheme is specific recipient, the signature is authenticated.Since the scheme adds the screen of some information parameters, the difficulty of deciphered keys and the security ofdigital signature system are increased.

  7. A New Deferred Sentencing Scheme

    Directory of Open Access Journals (Sweden)

    N. K. Chakravarti

    1968-10-01

    Full Text Available A new deferred sentencing scheme resembling double sampling scheme has been suggested from viewpoint of operational and administrative. It is recommended particularly when the inspection is destructive. The O.C. curves of the scheme for two sample sizes of 5 and 10 have been given.

  8. Reminiscences about numerical schemes

    CERN Document Server

    Godunov, Sergei K

    2008-01-01

    This preprint appeared firstly in Russian in 1997. Some truncated versions of this preprint were published in English and French, here a fully translated version is presented. The translation in English was done by O. V. Feodoritova and V. Deledicque to whom I express my gratitude. In the present paper I will describe how the first variant of the Godunov's scheme has been elaborated in 1953-1954 and tell about all modifications realized by myself (until 1969) and the group of scientists from the Institute of Applied Mathematics in Moscow (which has become the M.V.Keldysh Institute of Applied Mathematics).

  9. CONSIDERATIONS CONCERNING GUARANTEE SCHEMES

    Directory of Open Access Journals (Sweden)

    EMILIA CLIPICI

    2013-05-01

    Full Text Available When a large withdrawal from banks occurs, customers withdraw their deposits, so banks are likely to go bankrupt because of liquidity problems. There are several mechanisms that allow the banking system to avoid the phenomenon of massive withdrawals from banks. The most effective one is the deposit insurance. The deposit insurance is seen primarily as a means of protecting depositors of credit institutions, and secondly as a means of ensuring the stability of the banking system. This article described deposit guarantee scheme in Romania and other country.

  10. Pixel-Level Digital-to-Analog Conversion Scheme for Compact Data Drivers of Active Matrix Organic Light-Emitting Diodes with Low-Temperature Polycrystalline Silicon Thin-Film Transistors

    Science.gov (United States)

    Tae-Wook Kim,; Byong-Deok Choi,

    2010-03-01

    This paper shows that a part of a digital-to-analog conversion (DAC) function can be included in a pixel circuit to save the circuit area of an integrated data driver fabricated with low-temperature polycrystalline silicon thin-film transistors (LTPS-TFTs). Because the pixel-level DAC can be constructed by two TFTs and one small capacitor, the pixel circuit does not become markedly complex. The design of an 8-bit DAC, which combines a 6-bit resistor-string-based DAC and a 2-bit pixel-level DAC for a 4-in. diagonal VGA format active matrix organic light-emitting diode (AMOLED), is shown in detail. In addition, analysis results are presented, revealing that the 8-bit DAC scheme including a 2-bit pixel-level DAC with 1:3 demultiplexing can be applied to very high video formats, such as XGA, for a 3 to 4-in. diagonal AMOLED. Even for a 9- to 12-in. diagonal AMOLED, the proposed scheme can still be applied to the XGA format, even though no demultiplexing is allowed. The total height of the proposed 8-bit DAC is approximately 960 μm, which is almost one-half of that of the previous 6-bit resistor-string-based DAC.

  11. Secure mediated certificateless signature scheme

    Institute of Scientific and Technical Information of China (English)

    YANG Chen; MA Wen-ping; WANG Xin-mei

    2007-01-01

    Ju et al proposed a certificateless signature scheme with instantaneous revocation by introducing security mediator (SEM) mechanism. This article presents a detailed cryptoanalysis of this scheme and shows that, in their proposed scheme, once a valid signature has been produced, the signer can recover his private key information and the instantaneous revocation property will be damaged. Furthermore, an improved mediated signature scheme, which can eliminate these disadvantages, is proposed, and security proof of the improved scheme under elliptic curve factorization problem (ECFP) assumption and bilinear computational diffie-hellman problem (BCDH) assumption is also proposed.

  12. Scheme of thinking quantum systems

    International Nuclear Information System (INIS)

    A general approach describing quantum decision procedures is developed. The approach can be applied to quantum information processing, quantum computing, creation of artificial quantum intelligence, as well as to analyzing decision processes of human decision makers. Our basic point is to consider an active quantum system possessing its own strategic state. Processing information by such a system is analogous to the cognitive processes associated to decision making by humans. The algebra of probability operators, associated with the possible options available to the decision maker, plays the role of the algebra of observables in quantum theory of measurements. A scheme is advanced for a practical realization of decision procedures by thinking quantum systems. Such thinking quantum systems can be realized by using spin lattices, systems of magnetic molecules, cold atoms trapped in optical lattices, ensembles of quantum dots, or multilevel atomic systems interacting with electromagnetic field

  13. Design of a direct Z-scheme photocatalyst: Preparation and characterization of Bi{sub 2}O{sub 3}/g-C{sub 3}N{sub 4} with high visible light activity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinfeng [Department of Chemistry, Anhui Science and Technology University, Anhui, Fengyang 233100 (China); Department of Chemistry, Huaibei Normal University, Anhui, Huaibei 235000 (China); Hu, Yingfei; Jiang, Xiaoliang [Department of Chemistry, Huaibei Normal University, Anhui, Huaibei 235000 (China); Chen, Shifu, E-mail: chshifu@chnu.edu.cn [Department of Chemistry, Anhui Science and Technology University, Anhui, Fengyang 233100 (China); Department of Chemistry, Huaibei Normal University, Anhui, Huaibei 235000 (China); Meng, Sugang; Fu, Xianliang [Department of Chemistry, Huaibei Normal University, Anhui, Huaibei 235000 (China)

    2014-09-15

    Graphical abstract: - Highlights: • A direct Z-scheme photocatalyst Bi{sub 2}O{sub 3}/g-C{sub 3}N{sub 4} was prepared. • The photocatalyst exhibited a much higher activity than pure g-C{sub 3}N{sub 4}. • Bi{sub 2}O{sub 3}/g-C{sub 3}N{sub 4} as a typical Z-scheme photocatalyst was proved. • e{sup −} in the CB of Bi{sub 2}O{sub 3} and h{sup +} in the VB of g-C{sub 3}N{sub 4} are quickly combined. • e{sup −} in the CB of g-C{sub 3}N{sub 4} and h{sup +} in the VB of Bi{sub 2}O{sub 3} participate in redox reaction. - Abstract: A direct Z-scheme photocatalyst Bi{sub 2}O{sub 3}/g-C{sub 3}N{sub 4} was prepared by ball milling and heat treatment methods. The photocatalyst was characterized by X-ray powder diffraction (XRD), UV–vis diffuse reflection spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) surface areas, photoluminescence technique (PL), and electron spin resonance (ESR) technology. The photocatalytic activity was evaluated by degradation of methylene blue (MB) and rhodamine B (RhB). The results showed that Bi{sub 2}O{sub 3}/g-C{sub 3}N{sub 4} exhibited a much higher photocatalytic activity than pure g-C{sub 3}N{sub 4} under visible light illumination. The rate constants of MB and RhB degradation for Bi{sub 2}O{sub 3}(1.0 wt.%)/g-C{sub 3}N{sub 4} are about 3.4 and 5 times that of pure g-C{sub 3}N{sub 4}, respectively. The migration of photogenerated carriers adopts a Z-scheme mechanism. The photoexcited electrons in the CB of Bi{sub 2}O{sub 3} and photogenerated holes in the VB of g-C{sub 3}N{sub 4} are quickly combined, so the photoexcited electrons in the CB of g-C{sub 3}N{sub 4} and holes in the VB of Bi{sub 2}O{sub 3} participate in reduction and oxidation reactions, respectively. ·O{sub 2}{sup −}, ·OH and h{sup +} are the major reactive species for the Bi{sub 2}O{sub 3}/g-C{sub 3}N{sub 4} photocatalytic system.

  14. BI-DIRECTIONAL ANONYMOUS IDENTITY AUTHENTICATION SCHEME FOR CLOUD COMPUTING BASED ON SECURITY ACTIVE BUNDLE%基于安全活跃束S AB的匿名双向云身份认证方案

    Institute of Scientific and Technical Information of China (English)

    张琼文; 吴承荣

    2014-01-01

    Dynamic and transparent cloud brings infinite possibility to people’s life;meanwhile it also imposes greater challenges on theincreasing privacy and security problems of digital identity in virtual world.Digital identity has a close relationship with information services.Before accessing or sharing the resources,the identities of both users and services providers should be authenticated each other.In particular,when the identity theft is rampant,telling authentication on users,partners and cloud services providers is the crucial measurement.Weanalyse the status quo of cloud identity authentication and the challenges encountering,and propose a scheme named “security active bundle(SAB)cloud identity authentication”based on predicate encryption and Active Bundle idea,which realises the bi-directional anonymousauthentication between the end user and the cloud,or among the clouds.This scheme strengthens the privacy protection of personal sensitiveinformation and no longer depends on the trusted third party,etc.%动态透明的云给人们的生活带来了无限的可能,同时也对虚拟世界中与日俱增的数字身份的隐私和安全问题提出了更大的挑战。数字身份和信息服务有着密切关系,在访问或分享资源前,用户和服务双方的身份都有必要先通过认证。特别是当身份窃取猖獗的时候,有力地用户认证、合作伙伴认证、云服务提供商认证等是至关重要的措施。分析云身份认证的现状和面临的挑战,基于谓词加密和Active Bundle思想提出了安全活跃束SAB(Security Active Bundle)云身份认证方案,实现了终端用户与云以及云之间的双向匿名认证,加强了个人敏感信息隐私保护和不再依赖可信第三方等。

  15. Improved Ternary Subdivision Interpolation Scheme

    Institute of Scientific and Technical Information of China (English)

    WANG Huawei; QIN Kaihuai

    2005-01-01

    An improved ternary subdivision interpolation scheme was developed for computer graphics applications that can manipulate open control polygons unlike the previous ternary scheme, with the resulting curve proved to be still C2-continuous. Parameterizations of the limit curve near the two endpoints are given with expressions for the boundary derivatives. The split joint problem is handled with the interpolating ternary subdivision scheme. The improved scheme can be used for modeling interpolation curves in computer aided geometric design systems, and provides a method for joining two limit curves of interpolating ternary subdivisions.

  16. The impact of revised simplified Arakawa-Schubert scheme on the simulation of mean and diurnal variability associated with active and break phases of Indian summer monsoon using CFSv2

    Science.gov (United States)

    Ganai, Malay; Krishna, R. Phani Murali; Mukhopadhyay, P.; Mahakur, M.

    2016-08-01

    The impact of revised simplified Arakawa-Schubert (RSAS) convective parameterization scheme in Climate Forecast System (CFS) version 2 (CFSv2) on the simulation of active and break phases of Indian summer monsoon (ISM) has been investigated. The results revealed that RSAS showed better fidelity in simulating monsoon features from diurnal to daily scales during active and break periods as compared to SAS simulation. Prominent improvement can be noted in simulating diurnal phase of precipitation in RSAS over central India (CI) and equatorial Indian Ocean (EIO) region during active periods. The spatial distribution of precipitation largely improved in RSAS simulation during active and break episodes. CFSv2 with SAS simulation has noticeable dry bias over CI and wet bias over EIO region which appeared to be largely reduced in RSAS simulation during both phases of the intraseasonal oscillation (ISO). During active periods, RSAS simulates more realistic probability distribution function (PDF) in good agreement with the observation. The relative improvement has been identified in outgoing longwave radiation, monsoon circulations, and vertical velocities in RSAS over SAS simulation. The improvement of rainfall distribution appears to be contributed by proper simulation of convective rainfall in RSAS. CFSv2 with RSAS simulation is able to simulate observed diurnal cycle of rainfall over CI. It correctly reproduces the time of maximum rainfall over CI. It is found that the improved feedback between moisture and convective processes in RSAS may be attributed to its improved simulation. Besides improvement, RSAS could not reproduce proper tropospheric temperature, cloud hydrometeors over ISM domain which shows the scope for future development.

  17. Can adding web-based support to UK primary care exercise referral schemes improve patients’ physical activity levels? Intervention development for the e-coachER study.

    Directory of Open Access Journals (Sweden)

    Adrian Taylor

    2015-10-01

    -monitoring health behaviour and health, as well as modifiable options for local physical activity options. Conclusion: The Lifeguide platform for e-coachER is able to collect data on individual usage, and this will be used, along with semi-structured interviews, to conduct a process evaluation to fully understand if, for whom, and how the intervention facilitated long-term PA changes. Supported with funding from the NIHR (HTA Project: 13/25/20

  18. Hermite-interpolatory subdivision schemes

    NARCIS (Netherlands)

    Kuijt, Frans; Damme, van Ruud

    1998-01-01

    Stationary interpolatory subdivision schemes for Hermite data that consist of function values and first derivatives are examined. A general class of Hermite-interpolatory subdivision schemes is proposed, and some of its basic properties are stated. The goal is to characterise and construct certain c

  19. Homographic scheme for Riccati equation

    CERN Document Server

    Dubois, François

    2011-01-01

    In this paper we present a numerical scheme for the resolution of matrix Riccati equation, usualy used in control problems. The scheme is unconditionnaly stable and the solution is definite positive at each time step of the resolution. We prove the convergence in the scalar case and present several numerical experiments for classical test cases.

  20. On stochastic finite difference schemes

    OpenAIRE

    Gyongy, Istvan

    2013-01-01

    Finite difference schemes in the spatial variable for degenerate stochastic parabolic PDEs are investigated. Sharp results on the rate of $L_p$ and almost sure convergence of the finite difference approximations are presented and results on Richardson extrapolation are established for stochastic parabolic schemes under smoothness assumptions.

  1. Cost Based Droop Schemes for Economic Dispatch in Islanded Microgrids

    DEFF Research Database (Denmark)

    Chen, Feixiong; Chen, Minyou; Li, Qiang;

    2016-01-01

    In this paper, cost based droop schemes are proposed, to minimize the total active power generation cost in an islanded microgrid (MG), while the simplicity and decentralized nature of the droop control are retained. In cost based droop schemes, the incremental costs of distributed generators (DGs......) are embedded into the droop schemes, where the incremental cost is a derivative of the DG cost function with respect to output power. In the steady state, DGs share a single common frequency, and cost based droop schemes equate incremental costs of DGs, thus minimizing the total active power generation cost......, in terms of the equal incremental cost principle. Finally, simulation results in an islanded MG with high penetration of intermittent renewable energy sources are presented, to demonstrate the eectiveness, as well as plug and play capability of the cost based droop schemes....

  2. Multiuser Switched Diversity Scheduling Schemes

    CERN Document Server

    Shaqfeh, Mohammad; Alouini, Mohamed-Slim

    2012-01-01

    Multiuser switched-diversity scheduling schemes were recently proposed in order to overcome the heavy feedback requirements of conventional opportunistic scheduling schemes by applying a threshold-based, distributed, and ordered scheduling mechanism. The main idea behind these schemes is that slight reduction in the prospected multiuser diversity gains is an acceptable trade-off for great savings in terms of required channel-state-information feedback messages. In this work, we characterize the achievable rate region of multiuser switched diversity systems and compare it with the rate region of full feedback multiuser diversity systems. We propose also a novel proportional fair multiuser switched-based scheduling scheme and we demonstrate that it can be optimized using a practical and distributed method to obtain the feedback thresholds. We finally demonstrate by numerical examples that switched-diversity scheduling schemes operate within 0.3 bits/sec/Hz from the ultimate network capacity of full feedback sys...

  3. Coordinated renewable energy support schemes

    DEFF Research Database (Denmark)

    Morthorst, P.E.; Jensen, S.G.

    2006-01-01

    This paper illustrates the effect that can be observed when support schemes for renewable energy are regionalised. Two theoretical examples are used to explain interactive effects on, e.g., the price of power, conditions for conventional power producers, and changes in import and export of power...... RES-E support schemes already has a common liberalised power market. In this case the introduction of a common support scheme for renewable technologies will lead to more efficient sitings of renewable plants, improving economic and environmental performance of the total power system...

  4. An 8-bit Data Driving Scheme Based on Two-Step Digital-to-Analog Conversion for Integrated Data Drivers of Active-Matrix Organic Light-Emitting Diodes

    Science.gov (United States)

    Kim, Tae-Wook; Choi, Byong-Deok

    2012-03-01

    The two-step digital-to-analog conversion (DAC) scheme has been reported to be very area-efficient for thin-film transistor-liquid crystal display (TFT-LCD) data driver ICs, but it is not as well suited as it is for polycrystalline silicon (poly-Si) TFT integrated circuits. The charge redistribution in the two-step DAC process requires an operational amplifier in principle, which is most challenging for poly-Si TFT circuits. The proposed two-step DAC for active-matrix organic light-emitting diodes (AMOLEDs) makes the operational amplifier unnecessary by appropriately exploiting the preexisting capacitors in the pixel to compensate for the characteristic variations of TFTs. Moreover, the second-step DAC occurs at the same time as threshold voltage compensation, and it does not require additional time. By thoroughly analyzing area efficiency depending on the resolution decomposition between the first- and second-step DACs, we found that 5-bit coarse plus 3-bit fine DACs are best in terms of circuit area. When we designed a layout of the proposed 8-bit DAC on the basis of the 4 µm design rules, the DAC circuit area is no more than 72×637 µm2, which, to the best of our knowledge, is the most compact to date.

  5. Scheme Design for the Giant Forging Hydraulic Press Active Synchronous Control System%巨型模锻液压机主动同步控制方案的设计

    Institute of Scientific and Technical Information of China (English)

    刘忠伟

    2012-01-01

    The synchronous control system is the essential device to the giant forging hydraulic press. Its synchronization control performance will directly determine product quality. The main causes of working cylinder asynchronism and its effect on synchronous control performance were analyzed. According to the practical problems of synchronous control application, an active synchronism control scheme was proposed based on multi-point driver.%同步控制系统是巨型模锻液压机上必备的关键装置,其同步控制性能的好坏将直接决定产品的质量.在分析主工作缸不同步的成因及对同步控制性能影响的基础上,根据巨型模锻液压机同步控制的实际应用问题,提出一种基于多点驱动的主动同步控制方案.

  6. The Influence of Second-Hand Cigarette Smoke Exposure during Childhood and Active Cigarette Smoking on Crohn's Disease Phenotype Defined by the Montreal Classification Scheme in a Western Cape Population, South Africa.

    Directory of Open Access Journals (Sweden)

    Tawanda Chivese

    Full Text Available Smoking may worsen the disease outcomes in patients with Crohn's disease (CD, however the effect of exposure to second-hand cigarette smoke during childhood is unclear. In South Africa, no such literature exists. The aim of this study was to investigate whether disease phenotype, at time of diagnosis of CD, was associated with exposure to second-hand cigarette during childhood and active cigarette smoking habits.A cross sectional examination of all consecutive CD patients seen during the period September 2011-January 2013 at 2 large inflammatory bowel disease centers in the Western Cape, South Africa was performed. Data were collected via review of patient case notes, interviewer-administered questionnaire and clinical examination by the attending gastroenterologist. Disease phenotype (behavior and location was evaluated at time of diagnosis, according to the Montreal Classification scheme. In addition, disease behavior was stratified as 'complicated' or 'uncomplicated', using predefined definitions. Passive cigarette smoke exposure was evaluated during 3 age intervals: 0-5, 6-10, and 11-18 years.One hundred and ninety four CD patients were identified. Cigarette smoking during the 6 months prior to, or at time of diagnosis was significantly associated with ileo-colonic (L3 disease (RRR = 3.63; 95% CI, 1.32-9.98, p = 0.012 and ileal (L1 disease (RRR = 3.54; 95% CI, 1.06-11.83, p = 0.040 compared with colonic disease. In smokers, childhood passive cigarette smoke exposure during the 0-5 years age interval was significantly associated with ileo-colonic CD location (RRR = 21.3; 95% CI, 1.16-391.55, p = 0.040. No significant association between smoking habits and disease behavior at diagnosis, whether defined by the Montreal scheme, or stratified as 'complicated' vs 'uncomplicated', was observed.Smoking habits were associated with ileo-colonic (L3 and ileal (L1 disease at time of diagnosis in a South African cohort.

  7. Good governance for pension schemes

    CERN Document Server

    Thornton, Paul

    2011-01-01

    Regulatory and market developments have transformed the way in which UK private sector pension schemes operate. This has increased demands on trustees and advisors and the trusteeship governance model must evolve in order to remain fit for purpose. This volume brings together leading practitioners to provide an overview of what today constitutes good governance for pension schemes, from both a legal and a practical perspective. It provides the reader with an appreciation of the distinctive characteristics of UK occupational pension schemes, how they sit within the capital markets and their social and fiduciary responsibilities. Providing a holistic analysis of pension risk, both from the trustee and the corporate perspective, the essays cover the crucial role of the employer covenant, financing and investment risk, developments in longevity risk hedging and insurance de-risking, and best practice scheme administration.

  8. A Novel Iris Segmentation Scheme

    Directory of Open Access Journals (Sweden)

    Chen-Chung Liu

    2014-01-01

    Full Text Available One of the key steps in the iris recognition system is the accurate iris segmentation from its surrounding noises including pupil, sclera, eyelashes, and eyebrows of a captured eye-image. This paper presents a novel iris segmentation scheme which utilizes the orientation matching transform to outline the outer and inner iris boundaries initially. It then employs Delogne-Kåsa circle fitting (instead of the traditional Hough transform to further eliminate the outlier points to extract a more precise iris area from an eye-image. In the extracted iris region, the proposed scheme further utilizes the differences in the intensity and positional characteristics of the iris, eyelid, and eyelashes to detect and delete these noises. The scheme is then applied on iris image database, UBIRIS.v1. The experimental results show that the presented scheme provides a more effective and efficient iris segmentation than other conventional methods.

  9. Efficient and provably secure identification scheme without random oracles

    Institute of Scientific and Technical Information of China (English)

    LI Yan-ping; WANG Yu-min

    2009-01-01

    The research on the identification scheme is an important and active area in computer and communication security. A series of identification schemes were proposed to improve the efficiency and security of the protocols by various methods. Based on the hardness assumption of the discrete logarithm problem in a gap Diffie-Hellman group and the difficulty of the collusion attack algorithm with k traitors, an efficient identification scheme is presented. Without random oracle models, the proposed scheme is then proved secure against impersonation and reset attacks in both concurrent and reset attack setting. Since the proposed scheme is simple, memory-saving, computation-efficient, and perfectly-secure, it is well suitable for use in smart cards.

  10. Breeding schemes in reindeer husbandry

    Directory of Open Access Journals (Sweden)

    Lars Rönnegård

    2003-04-01

    Full Text Available The objective of the paper was to investigate annual genetic gain from selection (G, and the influence of selection on the inbreeding effective population size (Ne, for different possible breeding schemes within a reindeer herding district. The breeding schemes were analysed for different proportions of the population within a herding district included in the selection programme. Two different breeding schemes were analysed: an open nucleus scheme where males mix and mate between owner flocks, and a closed nucleus scheme where the males in non-selected owner flocks are culled to maximise G in the whole population. The theory of expected long-term genetic contributions was used and maternal effects were included in the analyses. Realistic parameter values were used for the population, modelled with 5000 reindeer in the population and a sex ratio of 14 adult females per male. The standard deviation of calf weights was 4.1 kg. Four different situations were explored and the results showed: 1. When the population was randomly culled, Ne equalled 2400. 2. When the whole population was selected on calf weights, Ne equalled 1700 and the total annual genetic gain (direct + maternal in calf weight was 0.42 kg. 3. For the open nucleus scheme, G increased monotonically from 0 to 0.42 kg as the proportion of the population included in the selection programme increased from 0 to 1.0, and Ne decreased correspondingly from 2400 to 1700. 4. In the closed nucleus scheme the lowest value of Ne was 1300. For a given proportion of the population included in the selection programme, the difference in G between a closed nucleus scheme and an open one was up to 0.13 kg. We conclude that for mass selection based on calf weights in herding districts with 2000 animals or more, there are no risks of inbreeding effects caused by selection.

  11. An arbitrated quantum signature scheme

    CERN Document Server

    Zeng, G; Zeng, Guihua; Keitel, Christoph H.

    2002-01-01

    The general principle for a quantum signature scheme is proposed and investigated based on ideas from classical signature schemes and quantum cryptography. The suggested algorithm is implemented by a symmetrical quantum key cryptosystem and Greenberger-Horne-Zeilinger (GHZ) triplet states and relies on the availability of an arbitrator. We can guarantee the unconditional security of the algorithm, mostly due to the correlation of the GHZ triplet states and the use of quantum one-time pads.

  12. Active surveillance scheme in three Romanian hospitals reveals a high prevalence and variety of carbapenamase-producing Gram-negative bacteria: a pilot study, December 2014 to May 2015.

    Science.gov (United States)

    Timofte, Dorina; Panzaru, Carmen Valentina; Maciuca, Iuliana Elena; Dan, Maria; Mare, Anca Delia; Man, Adrian; Toma, Felicia

    2016-06-23

    We report the findings of an active surveillance scheme for detection of asymptomatic carriers with carbapenemase-producing Gram-negative bacteria (CP-GNB) in Romanian hospitals. During a pilot study from December 2014 to May 2015, faecal cultures were screened in three hospitals (two large, one medium-size) for patients newly admitted to selected wards or inpatients transferred from other wards to an intensive-care unit. The study revealed a high prevalence of CP-GNB detected in 22/27 and 28/38 of the carbapenem non-susceptible isolates from Hospitals 1 and 3, respectively. CP-GNB identified through faecal screening included NDM-1-producing Serratia marcescens and Klebsiella pneumoniae, OXA-48-producing K. pneumoniae and OXA-23-producing Acinetobacter baumannii. The distribution of the CP-GNB varied between the hospitals, with NDM-1-producing S. marcescens and K. pneumoniae being prevalent in the north-central part of the country and OXA-23/24-producing A. baumannii, OXA-48-producing K.pneumoniae, Morganella morganii and VIM-2-producing Escherichia coli/Pseudomonas aeruginosa detected in the north-east of the country. Conjugation studies showed that carbapenem resistance was transferable and PCR-based replicon typing identified blaNDM-1 on IncFIIs in S. marcescens and K. pneumoniae from Hospital 1 and blaOXA-48 on IncL plasmids in all Klebsiella spp. isolates from Hospitals 1 and 3. Our findings underline the importance of active surveillance for detection of CP-GNB asymptomatic faecal carriers and suggest a likely endemic spread of CP-GNB in Romania. PMID:27363583

  13. Efficient Password-Typed Key Agreement Scheme

    CERN Document Server

    Aboud, Sattar J

    2010-01-01

    In this paper, we will study Lee, Kim and Yoo, a verifier password typed key agreement scheme and demonstrate that the scheme is not secure. Then, the authors will propose an enhanced verifier typed key agreement scheme relied on Lee, Kim and Yoo scheme and demonstrate that the propose scheme resists against password guessing attack and stolen verifier attack. The authors are claimed that the proposed scheme is more secure and efficient compare with Lee, Kim and Yoo.

  14. Top-quark pair production in a running mass scheme

    Energy Technology Data Exchange (ETDEWEB)

    Dowling, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

    2013-11-15

    Between the Tevatron and LHC, top-quark physics is now becoming an area for precision physics. This has lead to an increase in theoretical activity to match the experimental accuracy of top anti-top production. We discuss the difficulty in properly defining the top-quark mass as measured by experiments and present results for differential distributions of top-quark pair production in a running mass scheme. The use of such a scheme shows better convergence in the perturbative expansion and improves the scale dependence as opposed to the typical on-shell scheme.

  15. Robust Fallback Scheme for the Danish Automatic Voltage Control System

    DEFF Research Database (Denmark)

    Qin, Nan; Dmitrova, Evgenia; Lund, Torsten;

    2015-01-01

    This paper proposes a fallback scheme for the Danish automatic voltage control system. It will be activated in case of the local station loses telecommunication to the control center and/or the local station voltage violates the acceptable operational limits. It cuts in/out switchable and tap......-able shunts to maintain the voltage locally. The fallback scheme is fully selfregulated according to the predefined triggering logic. In order to keep the robustness and avoid many shunts are being triggered in a short term, the inverse time characteristic is used to trigger switching one by one. This scheme...

  16. Multiuser switched diversity scheduling schemes

    KAUST Repository

    Shaqfeh, Mohammad

    2012-09-01

    Multiuser switched-diversity scheduling schemes were recently proposed in order to overcome the heavy feedback requirements of conventional opportunistic scheduling schemes by applying a threshold-based, distributed, and ordered scheduling mechanism. The main idea behind these schemes is that slight reduction in the prospected multiuser diversity gains is an acceptable trade-off for great savings in terms of required channel-state-information feedback messages. In this work, we characterize the achievable rate region of multiuser switched diversity systems and compare it with the rate region of full feedback multiuser diversity systems. We propose also a novel proportional fair multiuser switched-based scheduling scheme and we demonstrate that it can be optimized using a practical and distributed method to obtain the feedback thresholds. We finally demonstrate by numerical examples that switched-diversity scheduling schemes operate within 0.3 bits/sec/Hz from the ultimate network capacity of full feedback systems in Rayleigh fading conditions. © 2012 IEEE.

  17. Nonlinear secret image sharing scheme.

    Science.gov (United States)

    Shin, Sang-Ho; Lee, Gil-Je; Yoo, Kee-Young

    2014-01-01

    Over the past decade, most of secret image sharing schemes have been proposed by using Shamir's technique. It is based on a linear combination polynomial arithmetic. Although Shamir's technique based secret image sharing schemes are efficient and scalable for various environments, there exists a security threat such as Tompa-Woll attack. Renvall and Ding proposed a new secret sharing technique based on nonlinear combination polynomial arithmetic in order to solve this threat. It is hard to apply to the secret image sharing. In this paper, we propose a (t, n)-threshold nonlinear secret image sharing scheme with steganography concept. In order to achieve a suitable and secure secret image sharing scheme, we adapt a modified LSB embedding technique with XOR Boolean algebra operation, define a new variable m, and change a range of prime p in sharing procedure. In order to evaluate efficiency and security of proposed scheme, we use the embedding capacity and PSNR. As a result of it, average value of PSNR and embedding capacity are 44.78 (dB) and 1.74t⌈log2 m⌉ bit-per-pixel (bpp), respectively.

  18. Energy partitioning schemes: a dilemma.

    Science.gov (United States)

    Mayer, I

    2007-01-01

    Two closely related energy partitioning schemes, in which the total energy is presented as a sum of atomic and diatomic contributions by using the "atomic decomposition of identity", are compared on the example of N,N-dimethylformamide, a simple but chemically rich molecule. Both schemes account for different intramolecular interactions, for instance they identify the weak C-H...O intramolecular interactions, but give completely different numbers. (The energy decomposition scheme based on the virial theorem is also considered.) The comparison of the two schemes resulted in a dilemma which is especially striking when these schemes are applied for molecules distorted from their equilibrium structures: one either gets numbers which are "on the chemical scale" and have quite appealing values at the equilibrium molecular geometries, but exhibiting a counter-intuitive distance dependence (the two-center energy components increase in absolute value with the increase of the interatomic distances)--or numbers with too large absolute values but "correct" distance behaviour. The problem is connected with the quick decay of the diatomic kinetic energy components. PMID:17328441

  19. Energy partitioning schemes: a dilemma.

    Science.gov (United States)

    Mayer, I

    2007-01-01

    Two closely related energy partitioning schemes, in which the total energy is presented as a sum of atomic and diatomic contributions by using the "atomic decomposition of identity", are compared on the example of N,N-dimethylformamide, a simple but chemically rich molecule. Both schemes account for different intramolecular interactions, for instance they identify the weak C-H...O intramolecular interactions, but give completely different numbers. (The energy decomposition scheme based on the virial theorem is also considered.) The comparison of the two schemes resulted in a dilemma which is especially striking when these schemes are applied for molecules distorted from their equilibrium structures: one either gets numbers which are "on the chemical scale" and have quite appealing values at the equilibrium molecular geometries, but exhibiting a counter-intuitive distance dependence (the two-center energy components increase in absolute value with the increase of the interatomic distances)--or numbers with too large absolute values but "correct" distance behaviour. The problem is connected with the quick decay of the diatomic kinetic energy components.

  20. Nonlinear secret image sharing scheme.

    Science.gov (United States)

    Shin, Sang-Ho; Lee, Gil-Je; Yoo, Kee-Young

    2014-01-01

    Over the past decade, most of secret image sharing schemes have been proposed by using Shamir's technique. It is based on a linear combination polynomial arithmetic. Although Shamir's technique based secret image sharing schemes are efficient and scalable for various environments, there exists a security threat such as Tompa-Woll attack. Renvall and Ding proposed a new secret sharing technique based on nonlinear combination polynomial arithmetic in order to solve this threat. It is hard to apply to the secret image sharing. In this paper, we propose a (t, n)-threshold nonlinear secret image sharing scheme with steganography concept. In order to achieve a suitable and secure secret image sharing scheme, we adapt a modified LSB embedding technique with XOR Boolean algebra operation, define a new variable m, and change a range of prime p in sharing procedure. In order to evaluate efficiency and security of proposed scheme, we use the embedding capacity and PSNR. As a result of it, average value of PSNR and embedding capacity are 44.78 (dB) and 1.74t⌈log2 m⌉ bit-per-pixel (bpp), respectively. PMID:25140334

  1. Pension scheme in Austria

    Directory of Open Access Journals (Sweden)

    Greta Alikaj

    2015-07-01

    Full Text Available Driven by unfavorable demographic developments and unsustainable, outdated or fragmented systems, pension reform has been at the top of political agendas across the globe for many years now (Prinz, Stanovnik & Stropnik, 2000. Over the last two decades, almost all western European countries have been trimming their public pension systems in an effort to strengthen pension sustainability. One main target of reform was to increase the retirement age. Other measures (e.g. changing the pension calculation, broadening the assessment base, changing the adjustment mechanism were designed to lower replacement rates. The reform process in the wide range of countries addressed by this survey differs considerably from country to country. This is why Allianz first introduced the Pension Sustainability Index (PSI, which combines the various characteristics of pension systems with the factors that influence them to help track and evaluate policy changes made in different countries around the world. In addressing the sustainability of a country’s public pension system, the PSI can give an indication of a country’s need for reforms to maintain long-term financial sustainability. This can be difficult to assess given the many country-specific institutional, technical and legal parameters. The PSI is able to evaluate the long-term sustainability of national pension systems and thus the pressure on governments to reform these (International pension Papers, 1.2014. The speed of reform, however, differs between countries. Those which recently introduced major reforms were able to improve in the PSI ranking because of active steps taken, while others were lost in comparison due to their passive policymaking.

  2. Discrete-time H-infinity robust active queue management scheme for uncertain TCP flow model%不确定TCP流模型的离散H∞鲁棒主动队列管理算法

    Institute of Scientific and Technical Information of China (English)

    周川; 何俊伟; 陈庆伟

    2013-01-01

    Considering the problem of congestion control for the time-varying and uncertain TCP/IP network, we proposed a novel discrete-time robust active queue management (AQM) scheme based on H-infinity feedback control for the TCP flow model with link capacity disturbance and parameter uncertainties simultaneously. In this method, the bandwidth occupied by short-lived connections is treated as the external disturbances, and the effect of both delay and parameter uncertainties is taken into account for the TCP/AQM system model. By using Lyapunov stability theory and LMI techniques, we propose a discrete-time robust H-infinity AQM controller to guarantee the asymptotic stability and robustness of the queue length response of a router queues. Finally the NS-2 simulation results demonstrate effectiveness of the proposed method.%针对TCP/IP网络存在参数时变和不确定性下的拥塞控制问题,提出一种新的基于H∞状态反馈控制的离散鲁棒主动列队管理算法(AQM).该方法针对不确定TCP流模型,将短期突发流所占据的带宽作为系统的外部干扰,同时考虑时滞和参数不确定性因素,基于Lyapunov稳定性理论和线性矩阵不等式技术,设计了离散鲁棒状态反馈控制器以保证路由器队列响应的稳定性和鲁棒性.最后,通过NS-2仿真验证了本文方法的有效性.

  3. Study on the sudation function of sweat gland-like cells differentiated from umbilical cord mesenchymal stem cells after being frozen and defrosted%汗腺样细胞经冻存复苏后再生汗腺功能的研究

    Institute of Scientific and Technical Information of China (English)

    马奎; 鲁刚; 杨思明; 孙同柱; 付小兵; 盛志勇

    2011-01-01

    To explore the biological characteristics and the function of sweat gland-like cells trans-differentiated from umbilical cord mcscnchymal stem cells (UCMSCs) after being deep freeze storage. Methods; Human UCMSCs and sweat gland cells were isolated, cultured and identified with specific markers. They were co-cultured to transform the UCMSCs to sweat gland-like cells. After being deep frozen and defrosted, the stem cells, which exhibited the phenotype of sweat gland cells, were implanted into scald injured paws of nude mice. The regeneration of the sweat gland cells was observed. Results;The transdiffcrcntiatcd sweat gland-like cells were successfully implanted into the scald paws of nude mice after being frozen and defrosted, which regenerated the function of perspiration. Pathological observation showed that sweat glands were regenerated. Conclusions: UCMSCs can be transdiffcrcntiatcd into sweat gland-like cells in vitro, and the deep frozen and defrosted sweat gland like cells can be implanted into a fresh wound to regenerate sweat glands.%目的:研究由人脐带间充质干细胞(UCMSCs)分化而来的汗腺样细胞在冻存与复苏后的生物学活性与促汗腺再生能力.方法:分离培养人UCMSCs 和人汗腺细胞,通过两种细胞共培养方式促进UCMSCs向汗腺细胞分化.分化后的干细胞经冻存、复苏处理后,局部移植于裸鼠烫伤脚掌,通过组织学观察和发汗试验观察汗腺组织再生修复情况.结果:由UCMSCs分化而来的汗腺样细胞经冻存、复苏、移植于裸鼠脚掌创面后,能够在创面形成汗腺结构并具有发汗功能.结论:UCMSCs经诱导分化为汗腺样细胞后,经冻存和复苏处理,在体移植后仍能够有效促进受损汗腺的修复与再生,有望为大面积重度烧伤患者汗腺的修复提供充足的种子细胞.

  4. FODA - TDMA satellite access scheme: description, implementation and environment simulation

    OpenAIRE

    Celandroni, Nedo; Ferro, Erina

    1987-01-01

    A Fifo Ordered Demand Assignment-TDMA (FODA) satellite access scheme is briefly presented and few notes about the current implementation are given. The scheme is designed to handle together packetized data, voice and immages traffic in a multiple access satellite broadcast channel of Mbits band. The channel is shared by as many as 64 simultaneously active earth stations capable to optimally share the channel capacity and also to multiplex the different traffic types, incoming from satellite u...

  5. Doppler Shift Compensation Schemes in VANETs

    Directory of Open Access Journals (Sweden)

    F. Nyongesa

    2015-01-01

    Full Text Available Over the last decade vehicle-to-vehicle (V2V communication has received a lot of attention as it is a crucial issue in intravehicle communication as well as in Intelligent Transportation System (ITS. In ITS the focus is placed on integration of communication between mobile and fixed infrastructure to execute road safety as well as nonsafety information dissemination. The safety application such as emergence alerts lays emphasis on low-latency packet delivery rate (PDR, whereas multimedia and infotainment call for high data rates at low bit error rate (BER. The nonsafety information includes multimedia streaming for traffic information and infotainment applications such as playing audio content, utilizing navigation for driving, and accessing Internet. A lot of vehicular ad hoc network (VANET research has focused on specific areas including channel multiplexing, antenna diversity, and Doppler shift compensation schemes in an attempt to optimize BER performance. Despite this effort few surveys have been conducted to highlight the state-of-the-art collection on Doppler shift compensation schemes. Driven by this cause we survey some of the recent research activities in Doppler shift compensation schemes and highlight challenges and solutions as a stock-taking exercise. Moreover, we present open issues to be further investigated in order to address the challenges of Doppler shift in VANETs.

  6. A robust anonymous biometric-based remote user authentication scheme using smart cards

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Das

    2015-04-01

    Full Text Available Several biometric-based remote user authentication schemes using smart cards have been proposed in the literature in order to improve the security weaknesses in user authentication system. In 2012, An proposed an enhanced biometric-based remote user authentication scheme using smart cards. It was claimed that the proposed scheme is secure against the user impersonation attack, the server masquerading attack, the password guessing attack, and the insider attack and provides mutual authentication between the user and the server. In this paper, we first analyze the security of An’s scheme and we show that this scheme has three serious security flaws in the design of the scheme: (i flaw in user’s biometric verification during the login phase, (ii flaw in user’s password verification during the login and authentication phases, and (iii flaw in user’s password change locally at any time by the user. Due to these security flaws, An’s scheme cannot support mutual authentication between the user and the server. Further, we show that An’s scheme cannot prevent insider attack. In order to remedy the security weaknesses found in An’s scheme, we propose a new robust and secure anonymous biometric-based remote user authentication scheme using smart cards. Through the informal and formal security analysis, we show that our scheme is secure against all possible known attacks including the attacks found in An’s scheme. The simulation results of our scheme using the widely-accepted AVISPA (Automated Validation of Internet Security Protocols and Applications tool ensure that our scheme is secure against passive and active attacks. In addition, our scheme is also comparable in terms of the communication and computational overheads with An’s scheme and other related existing schemes. As a result, our scheme is more appropriate for practical applications compared to other approaches.

  7. Electrical Injection Schemes for Nanolasers

    DEFF Research Database (Denmark)

    Lupi, Alexandra; Chung, Il-Sug; Yvind, Kresten

    2014-01-01

    Three electrical injection schemes based on recently demonstrated electrically pumped photonic crystal nanolasers have been numerically investigated: 1) a vertical p-i-n junction through a post structure; 2) a lateral p-i-n junction with a homostructure; and 3) a lateral p-i-n junction....... For this analysis, the properties of different schemes, i.e., electrical resistance, threshold voltage, threshold current, and internal efficiency as energy requirements for optical interconnects are compared and the physics behind the differences is discussed....

  8. ERM Scheme for Quantile Regression

    Directory of Open Access Journals (Sweden)

    Dao-Hong Xiang

    2013-01-01

    Full Text Available This paper considers the ERM scheme for quantile regression. We conduct error analysis for this learning algorithm by means of a variance-expectation bound when a noise condition is satisfied for the underlying probability measure. The learning rates are derived by applying concentration techniques involving the ℓ2-empirical covering numbers.

  9. Homogenization scheme for acoustic metamaterials

    KAUST Repository

    Yang, Min

    2014-02-26

    We present a homogenization scheme for acoustic metamaterials that is based on reproducing the lowest orders of scattering amplitudes from a finite volume of metamaterials. This approach is noted to differ significantly from that of coherent potential approximation, which is based on adjusting the effective-medium parameters to minimize scatterings in the long-wavelength limit. With the aid of metamaterials’ eigenstates, the effective parameters, such as mass density and elastic modulus can be obtained by matching the surface responses of a metamaterial\\'s structural unit cell with a piece of homogenized material. From the Green\\'s theorem applied to the exterior domain problem, matching the surface responses is noted to be the same as reproducing the scattering amplitudes. We verify our scheme by applying it to three different examples: a layered lattice, a two-dimensional hexagonal lattice, and a decorated-membrane system. It is shown that the predicted characteristics and wave fields agree almost exactly with numerical simulations and experiments and the scheme\\'s validity is constrained by the number of dominant surface multipoles instead of the usual long-wavelength assumption. In particular, the validity extends to the full band in one dimension and to regimes near the boundaries of the Brillouin zone in two dimensions.

  10. Robust Threshold Guillou-Quisquater Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; ZHANG Zhen-feng; FENG Deng-guo

    2005-01-01

    The deficiencies of the first threshold GuillouQuisquater signature scheme presented by Li-San Liu, ChengKang Chu and Wen-Guey Tzeng are analysised at first, and then a new threshold Guillou-Quisquater signature scheme is presented. The new scheme is unforgeable and robust against any adaptive adversary if the base Guillou-Quisquater signature scheme is unforgeable under the chosen message attack and computing the discrete logarithm modulo a prime is hard.This scheme can also achieve optimal resilience. However,the new scheme does not need the assumption that N is the product of two safe primes. The basic signature scheme underlying the new scheme is exactly Guillou-Quisquater signature scheme, and the additional strong computation assumption introduced by the first threshold Guillou-Quisquater scheme is weaken.

  11. Secure Undeniable Threshold Proxy Signature Scheme

    Directory of Open Access Journals (Sweden)

    Sattar J. Aboud

    2014-01-01

    Full Text Available the threshold proxy signature scheme allows the original signer to delegate a signature authority to the proxy group to cooperatively sign message on behalf of an original signer. In this paper, we propose a new scheme which includes the features and benefits of the RSA scheme. Also, we will evaluate the security of undeniable threshold proxy signature scheme with known signers. We find that the existing threshold proxy scheme is insecure against the original signer forgery. In this paper, we show the cryptanalysis of an existed scheme. Additional, we propose the secure, undeniable and known signers threshold proxy signature scheme which answers the drawback of an existed scheme. We also demonstrate that a threshold proxy signature suffers from a conspiracy of an original signer and a secret share dealer, that the scheme is commonly forgeable, and cannot offer undeniable. We claim that the proposed scheme offers the undeniable characteristic.

  12. Fair Electronic Payment Scheme Based on DSA

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-bin; HONG Fan; ZHU Xian

    2005-01-01

    We present a multi-signature scheme based on DSA and describes a fair electronic payment scheme based on improved DSA signatures. The scheme makes both sides in equal positions during the course of electronic transaction. A Trusted Third Party (TTP) is involved in the scheme to guarantee the fairness of the scheme for both sides. However, only during the course of registration and dispute resolution will TTP be needed. TTP is not needed during the normal payment stage.

  13. a Study of Multiplexing Schemes for Voice and Data.

    Science.gov (United States)

    Sriram, Kotikalapudi

    Voice traffic variations are characterized by on/off transitions of voice calls, and talkspurt/silence transitions of speakers in conversations. A speaker is known to be in silence for more than half the time during a telephone conversation. In this dissertation, we study some schemes which exploit speaker silences for an efficient utilization of the transmission capacity in integrated voice/data multiplexing and in digital speech interpolation. We study two voice/data multiplexing schemes. In each scheme, any time slots momentarily unutilized by the voice traffic are made available to data. In the first scheme, the multiplexer does not use speech activity detectors (SAD), and hence the voice traffic variations are due to call on/off only. In the second scheme, the multiplexer detects speaker silences using SAD and transmits voice only during talkspurts. The multiplexer with SAD performs digital speech interpolation (DSI) as well as dynamic channel allocation to voice and data. The performance of the two schemes is evaluated using discrete-time modeling and analysis. The data delay performance for the case of English speech is compared with that for the case of Japanese speech. A closed form expression for the mean data message delay is derived for the single-channel single-talker case. In a DSI system, occasional speech losses occur whenever the number of speakers in simultaneous talkspurt exceeds the number of TDM voice channels. In a buffered DSI system, speech loss is further reduced at the cost of delay. We propose a novel fixed-delay buffered DSI scheme. In this scheme, speech fill-in/hangover is not required because there are no variable delays. Hence, all silences that naturally occur in speech are fully utilized. Consequently, a substantial improvement in the DSI performance is made possible. The scheme is modeled and analyzed in discrete -time. Its performance is evaluated in terms of the probability of speech clipping, packet rejection ratio, DSI

  14. A NEW TWO-DIMENSIONAL SIGNAL DECOMPOSITION SCHEME USING THE EXTREME-LIFTING SCHEME

    Institute of Scientific and Technical Information of China (English)

    Liu Baofang; Ping Xijian; Deng Guanglin; Shao Meizhen

    2001-01-01

    This paper discusses the signal decomposition method using the extreme-lifting scheme and two two-dimensional decomposition schemes: separable one-dimensional scheme and two-dimensional scheme with quincunx sampling. The structure of the relation "~" between Ex and Ey of these two schemes is symmetrical and both these two schemes have shortcomings)An unsymmetrical scheme of the extreme-lifting scheme is proposed in this paper, which canbe directly used to decompose two-dimensional image and can get better decomposition result than the two schemes with little computation cost.

  15. WEIGHTED COMPACT SCHEME FOR SHOCK CAPTURING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new class of finite difference schemes--the weighted compact schemes are proposed. According to the idea of the WENO schemes, the weighted compact scheme is constructed by a combination of the approximations of derivatives on candidate stencils with properly assigned weights so that the non-oscillatory property is achieved when discontinuities appear. The primitive function reconstruction method of ENO schemes is applied to obtain the conservative form of the weighted compact scheme. This new scheme not only preserves the characteristic of standard compact schemes and achieves high order accuracy and high resolution using a compact stencil,but also can accurately capture shock waves and discontinuities without oscillation, Numerical examples show that the new scheme is very promising and successful.``

  16. Ion Polarization Scheme for MEIC

    CERN Document Server

    Kondratenko, A M; Filatov, Yu N; Derbenev, Ya S; Lin, F; Morozov, V S; Zhang, Y

    2016-01-01

    The choice of a figure 8 shape for the booster and collider rings of MEIC opens wide possibilities for preservation of the ion polarization during beam acceleration as well as for control of the polarization at the collider's interaction points. As in the case of accelerators with Siberian snakes, the spin tune is energy independent but is equal to zero instead of one half. The figure-8 topology eliminates the effect of arcs on the spin motion. There appears a unique opportunity to control the polarization of any particle species including deuterons, using longitudinal fields of small integrated strength (weak solenoids). Contrary to existing schemes, using weak solenoids in figure-8 colliders, one can control the polarization at the interaction points without essentially any effect on the beam's orbital characteristics. A universal scheme for control of the polarization using weak solenoids provides an elegant solution to the problem of ion acceleration completely eliminating resonant beam depolarization. It...

  17. Project financing renewable energy schemes

    International Nuclear Information System (INIS)

    The viability of many Renewable Energy projects is critically dependent upon the ability of these projects to secure the necessary financing on acceptable terms. The principal objective of the study was to provide an overview to project developers of project financing techniques and the conditions under which project finance for Renewable Energy schemes could be raised, focussing on the potential sources of finance, the typical project financing structures that could be utilised for Renewable Energy schemes and the risk/return and security requirements of lenders, investors and other potential sources of financing. A second objective is to describe the appropriate strategy and tactics for developers to adopt in approaching the financing markets for such projects. (author)

  18. Validation scheme for diagnostic tests

    International Nuclear Information System (INIS)

    The aim was to develop a scheme for the validation of assays developed in the research laboratory for the successful transfer and implementation in the diagnostic laboratory. Although logistically, temporally and economically challenging, proper validation minimizes the chance of failure and increases the possibility of successful transfer and implementation in the diagnostic laboratory. A properly validated assay, which includes good design, good quality control and good documentation, reduces the chances of liability and increases confidence in the assay both nationally and internationally

  19. Practical E-Payment Scheme

    Directory of Open Access Journals (Sweden)

    Mohammad Al-Fayoumi

    2010-05-01

    Full Text Available E-payment is now one of the most central research areas in e-commerce, mainly regarding online and offline payment scenarios. Customers are generally passive in e-commerce transaction. Relied on a blind signature, this paper introduces an e-payment protocol, in which customers have more initiative, and can terminate the transaction before possible cheats, its security is enhanced. Moreover, the cost of workers and communications falls down considerably while the cost of trusted authority and protecting information is increased. As there is no trusted authority in the proposed scheme, network overcrowding and conspiracy problems can be avoided. Furthermore, the protocol satisfies fairness and non-repudiation. This helps merchant and bank to speed up the financial transaction process and to give user instant services at any time. Also, in this paper, we will discuss an important e-payment protocol namely pay-word scheme and examine its advantages and limitations, which encourages the authors to improve the scheme that keeps all characteristics intact without compromise of the security robustness. The suggested protocol employs the idea of blind signature with the thought of hash chain. We will compare the proposed protocol with pay-word protocol and demonstrate that the proposed protocol offers more security and efficiency, which makes the protocol workable for real world services.

  20. A biometric signcryption scheme without bilinear pairing

    Science.gov (United States)

    Wang, Mingwen; Ren, Zhiyuan; Cai, Jun; Zheng, Wentao

    2013-03-01

    How to apply the entropy in biometrics into the encryption and remote authentication schemes to simplify the management of keys is a hot research area. Utilizing Dodis's fuzzy extractor method and Liu's original signcryption scheme, a biometric identity based signcryption scheme is proposed in this paper. The proposed scheme is more efficient than most of the previous proposed biometric signcryption schemes for that it does not need bilinear pairing computation and modular exponentiation computation which is time consuming largely. The analysis results show that under the CDH and DL hard problem assumption, the proposed scheme has the features of confidentiality and unforgeability simultaneously.

  1. An enhanced biometric authentication scheme for telecare medicine information systems with nonce using chaotic hash function.

    Science.gov (United States)

    Das, Ashok Kumar; Goswami, Adrijit

    2014-06-01

    Recently, Awasthi and Srivastava proposed a novel biometric remote user authentication scheme for the telecare medicine information system (TMIS) with nonce. Their scheme is very efficient as it is based on efficient chaotic one-way hash function and bitwise XOR operations. In this paper, we first analyze Awasthi-Srivastava's scheme and then show that their scheme has several drawbacks: (1) incorrect password change phase, (2) fails to preserve user anonymity property, (3) fails to establish a secret session key beween a legal user and the server, (4) fails to protect strong replay attack, and (5) lacks rigorous formal security analysis. We then a propose a novel and secure biometric-based remote user authentication scheme in order to withstand the security flaw found in Awasthi-Srivastava's scheme and enhance the features required for an idle user authentication scheme. Through the rigorous informal and formal security analysis, we show that our scheme is secure against possible known attacks. In addition, we simulate our scheme for the formal security verification using the widely-accepted AVISPA (Automated Validation of Internet Security Protocols and Applications) tool and show that our scheme is secure against passive and active attacks, including the replay and man-in-the-middle attacks. Our scheme is also efficient as compared to Awasthi-Srivastava's scheme. PMID:24888983

  2. Sellafield Site (including Drigg) emergency scheme manual

    International Nuclear Information System (INIS)

    This Scheme defines the organisation and procedures available should there be an accident at the Sellafield Site which results in, or may result in, the release of radioactive material, or the generation of a high radiation field, which might present a hazard to employees and/or the general public. Several categories of emergencies on the Sellafield Site are mentioned; a building emergency which is confined to one building, a Site emergency standby when the effects of a building emergency go outside that building, a Site emergency alert (District Emergency Standby) when a release of activity affects Site operations and could have serious Site effects and a District Emergency Alert when a radioactivity release may interfere with the normal activity of the General Public. A Drigg Emergency Standby situation would operate similarly at the Drigg Site. The detailed arrangements and responsibilities of appointed personnel are set out in this manual. (UK)

  3. Secret sharing scheme with inherited characteristic

    Institute of Scientific and Technical Information of China (English)

    Ye Zhenjun; Meng Fanzhen

    2006-01-01

    To assure the shareholders can look for their "legal" attorneys to renew the secret, once the secret sharing scheme is initialized, a secret sharing scheme with inherited characteristic is constructed. In this scheme, each shareholder can produce a new share by his algorithm, which is equivalent to the primary one. Together with other shares, the primary secret can be renewed. Since this scheme is constructed not by replacing the primary share with a new share produced by the dealer in his primitive secret sharing scheme, so no matter how much shares the shareholder produces, these shares can not be gathered together to renew the secret in this scheme. Compared with the existing secret sharing schemes, this scheme provides more agility for the shareholders by investing each of them a function but not affect its security.

  4. Ghana - Ghana Compact I Irrigation Schemes

    Data.gov (United States)

    Millenium Challenge Corporation — The Millennium Development Authority (MiDA) financed the construction of a new irrigation scheme in Kpong and the renovation of two irrigation schemes in Botanga...

  5. TVD schemes for open channel flow

    Science.gov (United States)

    Delis, A. I.; Skeels, C. P.

    1998-04-01

    The Saint Venant equations for modelling flow in open channels are solved in this paper, using a variety of total variation diminishing (TVD) schemes. The performance of second- and third-order-accurate TVD schemes is investigated for the computation of free-surface flows, in predicting dam-breaks and extreme flow conditions created by the river bed topography. Convergence of the schemes is quantified by comparing error norms between subsequent iterations. Automatically calculated time steps and entropy corrections allow high CFL numbers and smooth transition between different conditions. In order to compare different approaches with TVD schemes, the most accurate of each type was chosen. All four schemes chosen proved acceptably accurate. However, there are important differences between the schemes in the occurrence of clipping, overshooting and oscillating behaviour and in the highest CFL numbers allowed by a scheme. These variations in behaviour stem from the different orders and inherent properties of the four schemes.

  6. Elliptic Curve Blind Digital Signature Schemes

    Institute of Scientific and Technical Information of China (English)

    YOULin; YANGYixian; WENQiaoyan

    2003-01-01

    Blind signature schemes are important cryptographic protocols in guaranteeing the privacy or anonymity of the users.Three new blind signature schemes and their corresponding generalizations are pro-posed. Moreover, their securities are simply analyzed.

  7. EFFICIENCY PROBLEMS RELATED TO PERMANGANATE OXIDATION SCHEMES

    Science.gov (United States)

    Oxidation schemes for the in-situ destruction of chlorinated solvents, using potassium permanganate, are receiving considerable attention. Indication from field studies and from our own work are that permanganate oxidation schemes have inherent problems that could severely limit...

  8. Wireless Broadband Access and Accounting Schemes

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, we propose two wireless broadband access and accounting schemes. In both schemes, the accounting system adopts RADIUS protocol, but the access system adopts SSH and SSL protocols respectively.

  9. Linear multi-secret sharing schemes

    Institute of Scientific and Technical Information of China (English)

    XIAO Liangliang; LIU Mulan

    2005-01-01

    In this paper the linear multi-secret sharing schemes are studied by using monotone span programs. A relation between computing monotone Boolean functions by using monotone span programs and realizing multi-access structures by using linear multisecret sharing schemes is shown. Furthermore, the concept of optimal linear multi-secret sharing scheme is presented and the several schemes are proved to be optimal.

  10. Improvement of publicly verifiable authenticated encryption scheme

    Institute of Scientific and Technical Information of China (English)

    LEI Fei-yu; CHEN Wen; MA Chang-she; CHEN Ke-fei

    2007-01-01

    A weakness of unforgeability is found in Ma and Chen scheme, and the root cause is the susceptive linear design in the scheme. In order to avoid the weakness and susceptive linear design, an improvement by means of two mechanisms including quadratic residue and composite discrete logarithm is proposed, which can defeat the forgery attacks in Ma and Chen scheme. The new scheme remains good confidentiality, public verifiability and efficiency.

  11. Arbitrated quantum signature scheme with message recovery

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hwayean; Hong, Changho; Kim, Hyunsang; Lim, Jongin; Yang, Hyung Jin

    2004-02-16

    Two quantum signature schemes with message recovery relying on the availability of an arbitrator are proposed. One scheme uses a public board and the other does not. However both schemes provide confidentiality of the message and a higher efficiency in transmission.

  12. Quantum Signature Scheme with Weak Arbitrator

    Science.gov (United States)

    Luo, Ming-Xing; Chen, Xiu-Bo; Yun, Deng; Yang, Yi-Xian

    2012-07-01

    In this paper, we propose one quantum signature scheme with a weak arbitrator to sign classical messages. This scheme can preserve the merits in the original arbitrated scheme with some entanglement resources, and provide a higher efficiency in transmission and reduction the complexity of implementation. The arbitrator is costless and only involved in the disagreement case.

  13. Population Monotonic Path Schemes for Simple Games

    NARCIS (Netherlands)

    Ciftci, B.B.; Borm, P.E.M.; Hamers, H.J.M.

    2006-01-01

    A path scheme for a simple game is composed of a path, i.e., a sequence of coalitions that is formed during the coalition formation process and a scheme, i.e., a payoff vector for each coalition in the path.A path scheme is called population monotonic if a player's payoff does not decrease as the pa

  14. A Model of Hierarchical Key Assignment Scheme

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhigang; ZHAO Jing; XU Maozhi

    2006-01-01

    A model of the hierarchical key assignment scheme is approached in this paper, which can be used with any cryptography algorithm. Besides, the optimal dynamic control property of a hierarchical key assignment scheme will be defined in this paper. Also, our scheme model will meet this property.

  15. COMPARISON OF VISUAL CRYPTOGRAPHIC SCHEMES

    Directory of Open Access Journals (Sweden)

    M.Amarnath Reddy,

    2011-05-01

    Full Text Available Visual cryptography technique allows the visual information to be encrypted in such a way that their decryption can be performed by human visual system. This technique used to encrypt a image into shares such that stacking a sufficient number of shares reveals the secret images. In visual cryptography there are different technique like sub pixel, error diffusion, Boolean operation etc. Visual cryptography can be applied for copyright for images, access control to user images, Visual authentication and identification any kind images of images like (normal or digital. This paper compares various visual cryptography schemes in terms of security, quality of images, contrast, and reliability of images.

  16. Update on the Pyramid Scheme

    CERN Document Server

    Banks, Tom

    2012-01-01

    We summarize recent work in which we attempt to make a consistent model of LHC physics, from the Pyramid Scheme. The models share much with the NMSSM, in particular, enhanced tree level contributions to the Higgs mass and a preference for small tan {\\beta}. There are 3 different singlet fields, and a new strongly coupled gauge theory, so the constraints of perturbative unification are quite different. We outline our general approach to the model, which contains a Kahler potential for three of the low energy fields, which is hard to calculate. Detailed calculations, based on approximations to the Kahler potential, will be presented in a future publication.

  17. REMINDER: Saved Leave Scheme (SLS)

    CERN Multimedia

    2003-01-01

    Transfer of leave to saved leave accounts Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'* annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No 22B) can be transferred to the saved leave account at the end of the leave year (30 September). We remind you that unused leave of all those taking part in the saved leave scheme at the closure of the leave year accounts is transferred automatically to the saved leave account on that date. Therefore, staff members have no administrative steps to take. In addition, the transfer, which eliminates the risk of omitting to request leave transfers and rules out calculation errors in transfer requests, will be clearly shown in the list of leave transactions that can be consulted in EDH from October 2003 onwards. Furthermore, this automatic leave transfer optimizes staff members' chances of benefiting from a saved leave bonus provided that they ar...

  18. Optimal Timer Based Selection Schemes

    CERN Document Server

    Shah, Virag; Yim, Raymond

    2009-01-01

    Timer-based mechanisms are often used to help a given (sink) node select the best helper node among many available nodes. Specifically, a node transmits a packet when its timer expires, and the timer value is a monotone non-increasing function of its local suitability metric. The best node is selected successfully if no other node's timer expires within a 'vulnerability' window after its timer expiry, and so long as the sink can hear the available nodes. In this paper, we show that the optimal metric-to-timer mapping that (i) maximizes the probability of success or (ii) minimizes the average selection time subject to a minimum constraint on the probability of success, maps the metric into a set of discrete timer values. We specify, in closed-form, the optimal scheme as a function of the maximum selection duration, the vulnerability window, and the number of nodes. An asymptotic characterization of the optimal scheme turns out to be elegant and insightful. For any probability distribution function of the metri...

  19. Modification of QUICK scheme by skew points

    Energy Technology Data Exchange (ETDEWEB)

    Mirzaei, M.; Mohammadi, R.; Malekzadeh, M. [K.N. Toosi Univ. of Technology, Aerospace Engineering Dept., Tehran (Iran, Islamic Republic of)]. E-mail: Mirzaei@kntu.ac.ir

    2005-07-01

    This paper presents a new method for convective flux approximation based on inclusions of skew points. The scheme uses the truncated terms of QUICK scheme and with the aid of an equation extracted from momentum equations, the skew points will appear in the convective flux formula. The results show that the presented scheme has better accuracy than the other schemes. Diffusion fluxes are approximated using power law scheme and for evaluation of the performance of the presented method several test cases were carried out and the results are compared with the results of other numerical works and experimental data. (author)

  20. On symmetric and upwind TVD schemes

    Science.gov (United States)

    Yee, H. C.

    1986-01-01

    The performance of the upwind and symmetric total variation diminishing (TVD) schemes in viscous and inviscid airfoil steady-state calculations is considered, and the extension of the implicit second-order-accurate TVD scheme for hyperbolic systems of conservative laws in curvilinear coordinates is discussed. For two-dimensional steady-state applications, schemes are implemented in a conservative noniterative alternating direction implicit form, and results illustrate that the algorithm produces a fairly good solution for an RAE2822 airfoil calculation. The study demonstrates that the symmetric TVD scheme is as accurate as the upwind TVD scheme, while requiring less computational effort than it.

  1. A New Signature Scheme with Shared Verification

    Institute of Scientific and Technical Information of China (English)

    JIA Xiao-yun; LUO Shou-shan; YUAN Chao-wei

    2006-01-01

    With expanding user demands, digital signature techniques are also being expanded greatly, from single signature and single verification techniques to techniques supporting multi-users. This paper presents a new digital signature scheme vith shared verification based on the fiat-shamir signature scheme. This scheme is suitable not only for digital signatures of one public key, but also for situations where multiple public keys are required. In addition, the scheme can resist all kinds of collusion, making it more practicable and safer. Additionally it is more efficient than other schemes.

  2. Exact Finite Difference Scheme and Nonstandard Finite Difference Scheme for Burgers and Burgers-Fisher Equations

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2014-01-01

    Full Text Available We present finite difference schemes for Burgers equation and Burgers-Fisher equation. A new version of exact finite difference scheme for Burgers equation and Burgers-Fisher equation is proposed using the solitary wave solution. Then nonstandard finite difference schemes are constructed to solve two equations. Numerical experiments are presented to verify the accuracy and efficiency of such NSFD schemes.

  3. Exact Finite Difference Scheme and Nonstandard Finite Difference Scheme for Burgers and Burgers-Fisher Equations

    OpenAIRE

    Lei Zhang; Lisha Wang; Xiaohua Ding

    2014-01-01

    We present finite difference schemes for Burgers equation and Burgers-Fisher equation. A new version of exact finite difference scheme for Burgers equation and Burgers-Fisher equation is proposed using the solitary wave solution. Then nonstandard finite difference schemes are constructed to solve two equations. Numerical experiments are presented to verify the accuracy and efficiency of such NSFD schemes.

  4. Hybrid scheme for Brownian semistationary processes

    DEFF Research Database (Denmark)

    Bennedsen, Mikkel; Lunde, Asger; Pakkanen, Mikko S.

    We introduce a simulation scheme for Brownian semistationary processes, which is based on discretizing the stochastic integral representation of the process in the time domain. We assume that the kernel function of the process is regularly varying at zero. The novel feature of the scheme is to...... approximate the kernel function by a power function near zero and by a step function elsewhere. The resulting approximation of the process is a combination of Wiener integrals of the power function and a Riemann sum, which is why we call this method a hybrid scheme. Our main theoretical result describes the...... asymptotics of the mean square error of the hybrid scheme and we observe that the scheme leads to a substantial improvement of accuracy compared to the ordinary forward Riemann-sum scheme, while having the same computational complexity. We exemplify the use of the hybrid scheme by two numerical experiments...

  5. Hybrid Transmission Scheme for MIMO Relay Channels

    Directory of Open Access Journals (Sweden)

    Guangming Xu

    2009-11-01

    Full Text Available To improve the achievable rate for the MIMO channels, we propose a hybrid transmission (HT scheme that mixes half-duplex decode-and-forward cooperative relaying transmission (DFRH)with direct transmission (DT. In the HT scheme, the source message is divided into two parts: one is transmitted by DFRH scheme and another is transmitted by DT scheme. Precoding and decoding are considered to convert the original MIMO relay channel into several parallel subchannels so that resource allocation can be easily performed. We focus on the spatial subchannel and power allocation problem. The objective of this problem is to maximize the total achievable rate under the constraints of joint total transmission power. Simulation results show that significant capacity gain can be achieved by the HT scheme compared to the DT scheme and the pure DFRH scheme.

  6. A New Proxy Signature Scheme with Message Recovery Using Self-Certified Public Key

    Institute of Scientific and Technical Information of China (English)

    LI Ji-guo; ZHANG Yi-chen; ZHU Yue-long

    2005-01-01

    A proxy signature scheme with message recovery using self-certified public key is proposed, which withstands public key substitution attacks, active attacks, and forgery attacks. The proposed scheme accomplishes the tasks of public key verification, proxy signature verification, and message recovery in a logically single step. In addition, the proposed scheme satisfies all properties of strong proxy signature and does not use secure channel in the communication between the original signer and the proxy signature signer.

  7. A NEW ANONYMITY CONTROLLED E-CASH SCHEME

    Institute of Scientific and Technical Information of China (English)

    Zhang Fangguo; Wang Changjie; Wang Yumin

    2002-01-01

    E-cash is a type of very important electronic payment systems. The complete anonymity of E-cash can be used for criminal activities, so E-cash should be anonymity controlled.Moreover, Elliptic Curve Cryptography(ECC) has been regard as the mainstream of current public cryptography . In this paper, a new anonymity controlled E-cash scheme based on ECC for the first time and using a new technology-one-time key pairs digital signature is designed, and its security and efficiency are analyzed. In our scheme, the coin tracing and owner tracing can be implemented.

  8. Electrical injection schemes for nanolasers

    DEFF Research Database (Denmark)

    Lupi, Alexandra; Chung, Il-Sug; Yvind, Kresten

    2013-01-01

    The performance of injection schemes among recently demonstrated electrically pumped photonic crystal nanolasers has been investigated numerically. The computation has been carried out at room temperature using a commercial semiconductor simulation software. For the simulations two electrical...... of 3 InGaAsP QWs on an InP substrate has been chosen for the modeling. In the simulations the main focus is on the electrical and optical properties of the nanolasers i.e. electrical resistance, threshold voltage, threshold current and wallplug efficiency. In the current flow evaluation the lowest...... threshold current has been achieved with the lateral electrical injection through the BH; while the lowest resistance has been obtained from the current post structure even though this model shows a higher current threshold because of the lack of carrier confinement. Final scope of the simulations...

  9. Staggered Schemes for Fluctuating Hydrodynamics

    CERN Document Server

    Balboa, F; Delgado-Buscalioni, R; Donev, A; Fai, T; Griffith, B; Peskin, C S

    2011-01-01

    We develop numerical schemes for solving the isothermal compressible and incompressible equations of fluctuating hydrodynamics on a grid with staggered momenta. We develop a second-order accurate spatial discretization of the diffusive, advective and stochastic fluxes that satisfies a discrete fluctuation-dissipation balance, and construct temporal discretizations that are at least second-order accurate in time deterministically and in a weak sense. Specifically, the methods reproduce the correct equilibrium covariances of the fluctuating fields to third (compressible) and second (incompressible) order in the time step, as we verify numerically. We apply our techniques to model recent experimental measurements of giant fluctuations in diffusively mixing fluids in a micro-gravity environment [A. Vailati et. al., Nature Communications 2:290, 2011]. Numerical results for the static spectrum of non-equilibrium concentration fluctuations are in excellent agreement between the compressible and incompressible simula...

  10. Network Regulation and Support Schemes

    DEFF Research Database (Denmark)

    Ropenus, Stephanie; Schröder, Sascha Thorsten; Jacobsen, Henrik

    2009-01-01

    -in tariffs to market-based quota systems, and network regulation approaches, comprising rate-of-return and incentive regulation. National regulation and the vertical structure of the electricity sector shape the incentives of market agents, notably of distributed generators and network operators....... This article seeks to investigate the interactions between the policy dimensions of support schemes and network regulation and how they affect the deployment of distributed generation. Firstly, a conceptual analysis examines how the incentives of the different market agents are affected. In particular......, it will be shown that there frequently exists a trade-off between the creation of incentives for distributed generators and for distribution system operators to facilitate the integration of distributed generation. Secondly, the interaction of these policy dimensions is analyzed, including case studies based...

  11. A lightweight target-tracking scheme using wireless sensor network

    International Nuclear Information System (INIS)

    This paper describes a lightweight target-tracking scheme using wireless sensor network, where randomly distributed sensor nodes take responsibility for tracking the moving target based on the acoustic sensing signal. At every localization interval, a backoff timer algorithm is performed to elect the leader node and determine the transmission order of the localization nodes. An adaptive active region size algorithm based on the node density is proposed to select the optimal nodes taking part in localization. An improved particle filter algorithm performed by the leader node estimates the target state based on the selected nodes' acoustic energy measurements. Some refinements such as optimal linear combination algorithm, residual resampling algorithm, Markov chain Monte Carlo method are introduced in the scheme to improve the tracking performance. Simulation results validate the efficiency of the proposed tracking scheme

  12. Control Scheme for Distributed Generator Providing Network Voltage Support

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The distributed generator over the last 30 years has posed several challenges when they are connected to a distributed network. The most immediate problem is to change the voltage at the connection point depending on the power supplied to the network and may cause it to exceed statutory limits. This paper describes a new control scheme for a distributed generator for supporting the voltage control in the network, thus ensuring the distributed generator to contribute to network voltage management. The scheme performance is demonstrated by a model for a distributed generator connected to a distribution network. The result shows that using the new control scheme, the distribution network voltage constraints are maintained while maximizing the active power delivered by distributed generators.

  13. High resolution TVD schemes for interface tracking

    Science.gov (United States)

    Nandi, K.; Walker, S. P.; Date, A. W.

    2016-06-01

    A first order upwind difference scheme (UDS) is routinely adopted for representing convection terms in a discretised space. UDS provides stable solutions. However it also introduces false diffusion in situations in which the flow direction is oblique relative to the numerical grid or when the cell-Peclet number is large. In order to predict sharp interface, higher order upwind schemes are preferred because of they reduce numerical dissipation. In interfacial flows, density and viscosity vary sharply in space. Representation of convective terms by Total variation diminishing (TVD) schemes ensures reduced smearing without impairing convergence property. TVD schemes develop formulae for interpolation of a cell-face value of the transported variable. If the interpolated value is bounded by the neighbouring nodal values then the scheme is `Bounded'. However, not all TVD schemes possess this property of `Boundedness'. The Normalised Variable Diagram (NVD) defines a domain within which the TVD scheme is bounded. Thus by combining the features of both TVD schemes and ensuring that they fall with the defined area of NVD, the convergence as well as the boundedness of a computational scheme can be ensured. In this paper, six different higher order schemes are considered some which are TVD bounded or unbounded, to solve the well known interface tracking problem of Rayleigh-Taylor Instability. To the best of our knowledge, a comparison of combined TVD/NVD principles in the case of interface tracking problems has not been reported in published literature.

  14. Upwind schemes for the equations of magnetohydrodynamics

    International Nuclear Information System (INIS)

    This dissertation is concerned with applications of upwind schemes to ideal MHD equations. Difficulties in the construction of different schemes are discussed, and for Roe-type schemes a construction method is proposed, based on existence of a mean value Jacobian. It is shown that, in general, the procedure should be done numerically. Then a simplification of the procedure is shown by considering different simple averages. Basic properties of the scheme are preserved, i.e., first order of accuracy and high resolution of stationary discontinuities. Using the Roe-type schemes, explicit schemes to deal with the different time scales problem are considered. It is shown how one can numerically modify characteristic speeds so that the large time steps can be taken. Under certain restrictions convergence of the modified scheme to the weak solution of the system of conservation laws is proved. The Riemann problem for the MHD equations is shown, and an existence of a mixed wave is shown, i.e., switch-off or -on shock followed by an expansion rarefaction wave of the same family. Finally, numerical experiments using 2nd order high resolution schemes are conducted to support the above statements. Performance of the upwind scheme is compared with implicit and centered explicit schemes

  15. A Signature Scheme with Non-Repudiation

    Institute of Scientific and Technical Information of China (English)

    XIN Xiangjun; GUO Xiaoli; XIAO Guozhen

    2006-01-01

    Based on the Schnorr signature scheme, a new signature scheme with non-repudiation is proposed. In this scheme, only the signer and the designated receiver can verify the signature signed by the signer, and if necessary, both the signer and the designated receiver can prove and show the validity of the signature signed by the signer. The proof of the validity of the signature is noninteractive and transferable. To verify and prove the validity of the signature, the signer and the nominated receiver needn't store extra information besides the signature. At the same time, neither the signer nor the designated receiver can deny a valid signature signed. Then, there is no repudiation in this new signature scheme. According to the security analysis of this scheme, it is found the proposed scheme is secure against existential forgery on adaptive chosen message attack.

  16. CLOUD COMPUTING AND ITS PRICING SCHEMES

    Directory of Open Access Journals (Sweden)

    Varun Kamra

    2012-04-01

    Full Text Available Cloud computing is a rapidly emerging technology which involves deployment of various services like software, web services and virtualized infrastructure, as a product on public, private or hybrid clouds on lease basis. These services are charged by the respective pricing scheme for the cloud. The price varies with the number and type of data structures used for query execution. In this paper we describe static and dynamic pricing schemes for cloud cache. In static pricing scheme the prices are fixed for different resources which remain constant with time. Static pricing scheme does not benefit the service provider because it does not reflect the current market value. The dynamic pricing scheme can adapt as the time changes. According to the demand of a resource the pricing is done in dynamic pricing scheme so as to maximize the profit of the service provider. In addition to this, our paper explains characteristics and the delivery models for cloud computing in short.

  17. On Optimal Designs of Some Censoring Schemes

    Directory of Open Access Journals (Sweden)

    Dr. Adnan Mohammad Awad

    2016-03-01

    Full Text Available The main objective of this paper  is to explore suitability of some entropy-information measures for introducing a new optimality censoring criterion and to apply it to some censoring schemes from some underlying life-time models.  In addition, the  paper investigates four related issues namely; the  effect of the parameter of parent distribution on optimal scheme, equivalence of schemes based on Shannon and Awad sup-entropy measures, the conjecture that the optimal scheme is one stage scheme, and  a conjecture by Cramer and Bagh (2011 about Shannon minimum and maximum schemes when parent distribution is reflected power. Guidelines for designing an optimal censoring plane are reported together with theoretical and numerical results and illustrations.

  18. A privacy preserving secure and efficient authentication scheme for telecare medical information systems.

    Science.gov (United States)

    Mishra, Raghavendra; Barnwal, Amit Kumar

    2015-05-01

    The Telecare medical information system (TMIS) presents effective healthcare delivery services by employing information and communication technologies. The emerging privacy and security are always a matter of great concern in TMIS. Recently, Chen at al. presented a password based authentication schemes to address the privacy and security. Later on, it is proved insecure against various active and passive attacks. To erase the drawbacks of Chen et al.'s anonymous authentication scheme, several password based authentication schemes have been proposed using public key cryptosystem. However, most of them do not present pre-smart card authentication which leads to inefficient login and password change phases. To present an authentication scheme with pre-smart card authentication, we present an improved anonymous smart card based authentication scheme for TMIS. The proposed scheme protects user anonymity and satisfies all the desirable security attributes. Moreover, the proposed scheme presents efficient login and password change phases where incorrect input can be quickly detected and a user can freely change his password without server assistance. Moreover, we demonstrate the validity of the proposed scheme by utilizing the widely-accepted BAN (Burrows, Abadi, and Needham) logic. The proposed scheme is also comparable in terms of computational overheads with relevant schemes. PMID:25750176

  19. Space Vector Pulse Width Modulation Scheme for a Seven-Phase Voltage Source Inverter

    Directory of Open Access Journals (Sweden)

    Mohd. Arif Khan

    2011-09-01

    Full Text Available This paper analyses a simple space vector PWM (SVPWM scheme for a seven-phase voltage source inverter. At first the conventional method of producing sinusoidal output voltage  by utilizing six active and a zero space vectors are used to synthesis the input reference and then new PWM scheme called time equivalent space vector PWM is presented.  A comparison of the proposed scheme with the conventional scheme is presented based on various performance indices. Extensive Simulation results are provided to validate the findings

  20. Analysis of Paper reduction schemes to develop selection criteria for ofdm signals

    International Nuclear Information System (INIS)

    This paper presents a review of different PAPR (Peak to Average Power Ratio) reduction schemes of OFDM (Orthogonal Frequency Division Multiplexing) signals. The schemes that have been considered include Clipping and Filtering, Coding, ACE (Active Contstellation Extension), SLM (Selected Mapping), PTS (Partial Transmit Sequence), TI (Tone Injection) and TR (Tone Reservation). A comparative analysis has been carried out qualitatively. It has been demonstrated how these schemes can be combined with MIMO (Multiple Input Multiple Output) technologies. Finally, criteria for selection of PAPR reduction schemes of OFDM systems are discussed. (author)

  1. Blind Signature Scheme Based on Chebyshev Polynomials

    Directory of Open Access Journals (Sweden)

    Maheswara Rao Valluri

    2011-12-01

    Full Text Available A blind signature scheme is a cryptographic protocol to obtain a valid signature for a message from a signer such that signer’s view of the protocol can’t be linked to the resulting message signature pair. This paper presents blind signature scheme using Chebyshev polynomials. The security of the given scheme depends upon the intractability of the integer factorization problem and discrete logarithms ofChebyshev polynomials.

  2. Multi-object quantum traveling ballot scheme

    Institute of Scientific and Technical Information of China (English)

    Yuan Li; Guihua Zeng

    2009-01-01

    Based on quantum mechanics, a traveling ballot scheme with anonymity and secrecy is introduced to realize voting. By searching the objects in large amount of data bases, every voter may cast votes to his desired candidates. Therefore, the proposed scheme may be applied to voting with a great deal of candidates, such as network voting and so on. The security analysis of the present scheme is also performed.

  3. Payment schemes for environmental services in watersheds

    OpenAIRE

    Food and Agriculture Organization of the United Nations.‏ United Nations Development Programme

    2004-01-01

    Payment schemes for environmental services (PES) are innovative instruments for natural resources management which are increasingly being applied in Latin America. In a watershed context, PES schemes generally involve the implementation of market mechanisms to compensate upstream landowners in order to maintain or modify a particular land use that is affecting the availability and/or quality of the water resources for downstream users. The Regional Forum on Payment Schemes for Environmental S...

  4. SYNCHRONIZATION RECOVERY SCHEME IN WATERMARKING DETECTION

    Institute of Scientific and Technical Information of China (English)

    Xiao Weiwei; Zhang Li; Ji Zhen; Zhang Jihong

    2003-01-01

    Most proposed digital watermarking algorithms are sensitive to geometric attacksbecause the synchronization information of watermark embedding and detection is destroyed. Inthis letter a novel synchronization recovery scheme based on image normalization is proposed. Thepresented scheme does not require the original image and can be applied to various watermarksystems. A wavelet-based watermarking scheme is proposed as an example and experimentalresults show that it is robust to geometric attacks.

  5. Quantum Authentication Scheme Based on Entanglement Swapping

    Science.gov (United States)

    Penghao, Niu; Yuan, Chen; Chong, Li

    2016-01-01

    Based on the entanglement swapping, a quantum authentication scheme with a trusted- party is proposed in this paper. With this scheme, two users can perform mutual identity authentication to confirm each other's validity. In addition, the scheme is proved to be secure under circumstances where a malicious attacker is capable of monitoring the classical and quantum channels and has the power to forge all information on the public channel.

  6. The Pharmaceutical Benefits Scheme 2003–2004

    OpenAIRE

    Harvey, Ken J

    2005-01-01

    The Pharmaceutical Benefits Scheme (PBS) grew by 8% in 2003–04; a slower rate than the 12.0% pa average growth over the last decade. Nevertheless, the sustainability of the Scheme remained an ongoing concern given an aging population and the continued introduction of useful (but increasingly expensive) new medicines. There was also concern that the Australia-United States Free Trade Agreement could place further pressure on the Scheme. In 2003, as in 2002, the government proposed a 27% increa...

  7. Numerical schemes for low Mach wave breaking

    OpenAIRE

    Golay, Frédéric; Helluy, Philippe

    2007-01-01

    International audience In this work, we describe a finite volume scheme for the compu- tation of incompressible air-water flows. We use an artificial compressibility approach that permits us to use a completely explicit scheme. We describe successively the low Mach preconditioning of the scheme, the Riemann solver and the non-conservative approach that is used to suppress velocity-pressure oscillations, the second order extensions and the parallel implementation. Then it is applied to the ...

  8. New Certificateless Blind Ring Signature Scheme

    Directory of Open Access Journals (Sweden)

    Hua Sun

    2013-07-01

    Full Text Available A new certificateless blind ring signature scheme was proposed in this paper. The scheme could not only avoid the problem of certificate management of public key certificate cryptography, but also overcome the inherent key-escrow problem of identity-based public key cryptography. In the last, by using bilinear pairing technique, it was proved that this scheme satisfied the security of existential unforgeability, blindness and unconditional anonymity.

  9. Input Scheme for Hindi Using Phonetic Mapping

    OpenAIRE

    Joshi, Nisheeth; Mathur, Iti

    2010-01-01

    Written Communication on Computers requires knowledge of writing text for the desired language using Computer. Mostly people do not use any other language besides English. This creates a barrier. To resolve this issue we have developed a scheme to input text in Hindi using phonetic mapping scheme. Using this scheme we generate intermediate code strings and match them with pronunciations of input text. Our system show significant success over other input systems available.

  10. Darboux transformations for a 6-point scheme

    OpenAIRE

    Nieszporski, Maciej

    2006-01-01

    We introduce (binary) Darboux transformation for general differential equation of the second order in two independent variables. We present a discrete version of the transformation for a 6-point difference scheme. The scheme is appropriate to solving a hyperbolic type initial-boundary value problem. We discuss several reductions and specifications of the transformations as well as construction of other Darboux covariant schemes by means of existing ones. In particular we introduce a 10-point ...

  11. Acceleration of Runge-Kutta integration schemes

    OpenAIRE

    Udwadia, Firdaus E.; Phailaung Phohomsiri

    2004-01-01

    A simple accelerated third-order Runge-Kutta-type, fixed time step, integration scheme that uses just two function evaluations per step is developed. Because of the lower number of function evaluations, the scheme proposed herein has a lower computational cost than the standard third-order Runge-Kutta scheme while maintaining the same order of local accuracy. Numerical examples illustrating the computational efficiency and accuracy are presented and the actual speedup when the accelerated alg...

  12. Incorporating Partner Practice and Writing and Self-Regulation into the Theme Scheme Program.

    Science.gov (United States)

    Williams, Joanna P.

    2003-01-01

    This article discusses activities developed for the "Theme Scheme," an instructional program for elementary and middle school children at risk for failure. "Theme Scheme" is a listening and reading comprehension program that uses peer-assisted learning strategies and writing exercises to teach students to understand text at an abstract,…

  13. A new access scheme in OFDMA systems

    Institute of Scientific and Technical Information of China (English)

    GU Xue-lin; YAN Wei; TIAN Hui; ZHANG Ping

    2006-01-01

    This article presents a dynamic random access scheme for orthogonal frequency division multiple access (OFDMA) systems. The key features of the proposed scheme are:it is a combination of both the distributed and the centralized schemes, it can accommodate several delay sensitivity classes,and it can adjust the number of random access channels in a media access control (MAC) frame and the access probability according to the outcome of Mobile Terminals access attempts in previous MAC frames. For floating populated packet-based networks, the proposed scheme possibly leads to high average user satisfaction.

  14. Efficient Certificateless Signcryption Scheme from Weil Pairing

    Directory of Open Access Journals (Sweden)

    Gang Yu

    2011-08-01

    Full Text Available Certificateless signcryption has both the advantage of certificateless public key cryptography, which overcome the escrow problem inherited from identity based cryptography without the use of certificates as in traditional public key cryptography, and signcryption which can fulfill both the functions of signature and encryption in a logical signal step. In this paper, we explicit the security model for certificateless signcryption and propose an efficient certificateless signcryption scheme from Weil pairings. The new scheme not only can be proved to be secure in our model but also can simultaneously provide public verifiability and forward security. Furthermore, compared with existing schemes, the new scheme is more efficient.

  15. An Improved Proxy Multi-Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    GU Li-ze; ZHANG Sheng; YANG Yi-xian

    2005-01-01

    Based on the Kim-like's proxy multi-signature scheme[1],an improved proxy multi-signature scheme is proposed.The new scheme overcomes the two problems in the Kim-like's proxy multi-signature scheme:(1)Security issue(every original signer can forge a valid proxy multi-signature for any message);(2)Efficiency issue(both the size of the proxy multi-signature and the efficiency of signature checking are dependent on the number of the original signers).

  16. Optimizing Decision Tree Attack on CAS Scheme

    Directory of Open Access Journals (Sweden)

    PERKOVIC, T.

    2016-05-01

    Full Text Available In this paper we show a successful side-channel timing attack on a well-known high-complexity cognitive authentication (CAS scheme. We exploit the weakness of CAS scheme that comes from the asymmetry of the virtual interface and graphical layout which results in nonuniform human behavior during the login procedure, leading to detectable variations in user's response times. We optimized a well-known probabilistic decision tree attack on CAS scheme by introducing this timing information into the attack. We show that the developed classifier could be used to significantly reduce the number of login sessions required to break the CAS scheme.

  17. The UNCLE finite element scheme

    International Nuclear Information System (INIS)

    A completely general finite element scheme, implemented in the UKAEA Reactor Group is outlined. UNCLE is not a complete, self-contained program. It is a framework of routines that provide the common services required by all general purpose finite element programs, whether for heat transfer, stress analysis or any other linear (or piece-wise linear) problem. These services are: input of mesh, geometry, loads (etc) and material data: matrix and load vector calculation and assembly (including handling of standard boundary conditions); solution of global matrix (elimination and conjugate gradient methods); output (printed and graphical) of initial geometry, displacements, stresses, final geometry etc; facilities for iteration for non-linear problems and time integration; mass matrix reduction, dynamic analysis of reduced problem and expansion of displacements to full problem. The framework is written to handle 1, 2, 3 or more dimensions equally efficiently. To produce a general purpose program for a particular range of applications it is only necessary to provide a set of element subroutines specialised to the application (heat transfer, framework analysis, continuum stress analysis etc)

  18. Improvement of Laih and Yen's multisignature scheme

    Institute of Scientific and Technical Information of China (English)

    谢琪; 于秀源

    2004-01-01

    A new attack is proposed to show that a specified group of verifiers can cooperate to forge the signature for any message by secret key substitution due to the leaked secret key or by the group public key adjustment because of the renewed members. This paper presents the improvement scheme which overcomes the security weakness of Laih and Yen's scheme.

  19. Consolidation of the health insurance scheme

    CERN Multimedia

    Association du personnel

    2009-01-01

    In the last issue of Echo, we highlighted CERN’s obligation to guarantee a social security scheme for all employees, pensioners and their families. In that issue we talked about the first component: pensions. This time we shall discuss the other component: the CERN Health Insurance Scheme (CHIS).

  20. Mobile Machine for E-payment Scheme

    Directory of Open Access Journals (Sweden)

    Sattar J Aboud

    2010-11-01

    Full Text Available In this article e-payment scheme by mobile machine is considered. The requirements for a mobile machine in e-payment are presented, particularly when merchant employing accounts for payments and when using advertising. In the proposed scheme we will use the public key infrastructure and certificate for authenticate purchaser and merchant and to secure the communication between them.

  1. Mixed ultrasoft/norm-conserved pseudopotential scheme

    DEFF Research Database (Denmark)

    Stokbro, Kurt

    1996-01-01

    A variant of the Vanderbilt ultrasoft pseudopotential scheme, where the norm conservation is released for only one or a few angular channels, is presented. Within this scheme some difficulties of the truly ultrasoft pseudopotentials are overcome without sacrificing the pseudopotential softness. (...

  2. A New Public-Key Encryption Scheme

    Institute of Scientific and Technical Information of China (English)

    Hai-Bo Tian; Xi Sun; Yu-Min Wang

    2007-01-01

    This paper proposes a new public-key encryption scheme which removes one element from the public-key tuple of the original Cramer-Shoup scheme.As a result, a ciphertext is not a quadruple but a triple at the cost of a strong assumption,the third version of knowledge of exponent assumption (KEA3).Under assumptions of KEA3, a decision Diffie-Hellman (DDH) and a variant of target collision resistance (TCRv), the new scheme is proved secure against indistinguishable adaptive chosen ciphertext attack (IND-CCA2).This scheme is as efficient as Damgard ElGamal (DEG) scheme when it makes use of a well-known algorithm for product of exponentiations.The DEG scheme is recently proved IND-CCA1 secure by Bellare and Palacio in ASIACRYPT 2004 under another strong assumption.In addition to our IND-CCA2 secured scheme, we also believe that the security proof procedure itself provides a well insight for ElGamal-based encryption schemes which are secure in real world.

  3. Finite volume renormalization scheme for fermionic operators

    OpenAIRE

    Monahan, Christopher; Orginos, Kostas

    2013-01-01

    We propose a new finite volume renormalization scheme. Our scheme is based on the Gradient Flow applied to both fermion and gauge fields and, much like the Schr\\"odinger functional method, allows for a nonperturbative determination of the scale dependence of operators using a step-scaling approach. We give some preliminary results for the pseudo-scalar density in the quenched approximation.

  4. Unconditionnally stable scheme for Riccati equation

    CERN Document Server

    Dubois, François; 10.1051/proc:2000003

    2011-01-01

    We present a numerical scheme for the resolution of matrix Riccati equation used in control problems. The scheme is unconditionnally stable and the solution is definite positive at each time step of the resolution. We prove the convergence in the scalar case and present several numerical experiments for classical test cases.

  5. Evaluating arguments based on Toulmin's scheme

    NARCIS (Netherlands)

    Verheij, Bart; Hitchcock, D; Verheij, B

    2006-01-01

    Toulmin's scheme for the layout of arguments (1958) represents an influential tool for the analysis of arguments. The scheme enriches the traditional premises-conclusion model of arguments by distinguishing additional elements, like warrant, backing and rebuttal. The present paper contains a formal

  6. Novel Link Adaptation Schemes for OFDM System

    Institute of Scientific and Technical Information of China (English)

    LEI Ming; CAI Peng; XU Yue-shan; ZHANG Ping

    2003-01-01

    Orthogonal Frequency Division Multiplexing (OFDM) is the most promising technique supporting the high data rate transmission. The combination of the link adaptation and OFDM can further increase the spectral efficiency. In this paper, we put forward two link adaptation schemes for OFDM system which have the advantages of both flexibility and practicability. Both of the two novel link adaptation schemes are based on the iterative mechanism to allocate the bit and power to subcarriers according to their channel gains and noisy levels which are assumed to be already known at the transmitter. The candidate modulation modes are determined freely before the link adaptation schemes are performed. The distinction between the two novel link adaptation schemes is that in the novel scheme A, the modulation mode is upgraded to the neighboring higher-order mode, while in the novel scheme B the modulation is upgraded to the genuine optimal mode. Therefore, the novel scheme A has the advantage of lower complexity and the novel scheme B has the advantage of higher spectral efficiency.

  7. A Secure Threshold Group Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaoming; Fu Fangwei

    2003-01-01

    The threshold group signature is an important kind of signature. So far, many threshold group signature schemes have been proposed, but most of them suffer from conspiracy attack and are insecure. In this paper, a secure threshold group signature scheme is proposed. It can not only satisfy the properties of the threshold group signature, but also withstand the conspiracy attack

  8. A hierarchical classification scheme of psoriasis images

    DEFF Research Database (Denmark)

    Maletti, Gabriela Mariel; Ersbøll, Bjarne Kjær

    2003-01-01

    A two-stage hierarchical classification scheme of psoriasis lesion images is proposed. These images are basically composed of three classes: normal skin, lesion and background. The scheme combines conventional tools to separate the skin from the background in the first stage, and the lesion from...

  9. Cornering (3+1) sterile neutrino schemes

    CERN Document Server

    Maltoni, M; Valle, José W F

    2001-01-01

    Using the most recent atmospheric neutrino data, as well as short-baseline and tritium $\\beta$-decay data we show that (3+1) sterile neutrino schemes are severely disfavored, in contrast to the theoretically favored (2+2) schemes.

  10. Two level scheme solvers for nuclear spectroscopy

    Science.gov (United States)

    Jansson, Kaj; DiJulio, Douglas; Cederkäll, Joakim

    2011-10-01

    A program for building level schemes from γ-spectroscopy coincidence data has been developed. The scheme builder was equipped with two different algorithms: a statistical one based on the Metropolis method and a more logical one, called REMP (REcurse, Merge and Permute), developed from scratch. These two methods are compared both on ideal cases and on experimental γ-ray data sets. The REMP algorithm is based on coincidences and transition energies. Using correct and complete coincidence data, it has solved approximately half a million schemes without failures. Also, for incomplete data and data with minor errors, the algorithm produces consistent sub-schemes when it is not possible to obtain a complete scheme from the provided data.

  11. Splitting scheme for poroelasticity and thermoelasticity problems

    Science.gov (United States)

    Vabishchevich, P. N.; Vasil'eva, M. V.; Kolesov, A. E.

    2014-08-01

    Boundary value problems in thermoelasticity and poroelasticity (filtration consolidation) are solved numerically. The underlying system of equations consists of the Lamé stationary equations for displacements and nonstationary equations for temperature or pressure in the porous medium. The numerical algorithm is based on a finite-element approximation in space. Standard stability conditions are formulated for two-level schemes with weights. Such schemes are numerically implemented by solving a system of coupled equations for displacements and temperature (pressure). Splitting schemes with respect to physical processes are constructed, in which the transition to a new time level is associated with solving separate elliptic problems for the desired displacements and temperature (pressure). Unconditionally stable additive schemes are constructed by choosing a weight of a three-level scheme.

  12. Comparison among sea surface roughness schemes

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Based on the measurements from the US National Data Buoy Center 3-m discus buoy site No.44004 (38.5°N, 70.47°W) from January 1 to March 31 of 2003, with the COARE algorithm (Version 3.0), the results from four parameterization schemes developed recently for sea surface aerodynamic roughness length were compared with each other. Calculations of frictional speed u*, drag coefficient Cd and wind stress τ indicate that the calculated frictional velocities from the four schemes (8.50%-16.20%, the normalized standard error estimate, or NSEE), the computed drag coefficients and wind stress (respectively 15.08%-28.67% and 17.26%-50.59% NSEE) are reasonable. Schemes YT96 and GW03 are consistent. The O02 scheme gives overestimated values for u* and Cd. Schemes TY01 and GW03 display discontinuous characteristics in handling young wave data.

  13. An Efficient Forward Secure Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    YU Jia; KONG Fan-yu; LI Da-xing

    2006-01-01

    A new efficient forward secure signature scheme based on bilinear pairings is presented in this paper.Each complexity of key generation, key update, signing and verifying algorithms in this scheme is O(1) in terms of the total number of time periods T. Because a new structure in node secret key storage and a unique strategy in key update are employed, the signing and verifying costs don't grow when T increases. At the same time, the key generation and key update algorithms are efficiently constructed thanks to using the pre-order traversal technique of binary trees. Compared with other schemes based on bilinear pairings, the signature size in this scheme is very short, which doesn't change with T increasing. The scheme is forward secure in random oracle model assuming CDH problem is hard.

  14. A massive momentum-subtraction scheme

    CERN Document Server

    Boyle, Peter; Khamseh, Ava

    2016-01-01

    We introduce a new massive renormalization scheme, denoted mSMOM, as a modification of the existing RI/SMOM scheme. We use SMOM for defining renormalized fermion bilinears in QCD at non-vanishing fermion mass. This scheme has properties similar to those of the SMOM scheme, such as the use of non-exceptional symmetric momenta, while in contrast to SMOM, it defines the renormalized fields away from the chiral limit. Here we discuss some of the properties of mSMOM, and present non-perturbative arguments for deriving some renormalization constants. The results of a 1-loop calculation in dimensional regularization are briefly summarised to illustrate some properties of the scheme.

  15. Threshold Decryption Scheme with Multiple Policies

    Institute of Scientific and Technical Information of China (English)

    FEI Ru-chun; WANG Li-na

    2005-01-01

    Based on the difficulty in computing discrete logarithm and square root on some special conditions, we propose a basic threshold secret sharing scheme for multiple secrets with multiple policies, which allows a group of users to share multiple secret keys and only one secret shadow to be kept by each user. An efficient threshold decryption scheme with multiple policies is designed on the basis of the basic threshold scheme. This decryption scheme allows multiple secret keys to be shared among a group of users, and each user to keep only one secret shadow. Different public keys can be used to encrypt documents. If and only if the number of cooperated users who keep the secret shadows is greater than or equal to the threshold value of the corresponding secret key,they can cooperate to decrypt the documents. It is proved that the proposed scheme has very strong security, unless the attackers can solve the discrete logarithm problem and the square root problem.

  16. A DRM Scheme Using File Physical Information

    Directory of Open Access Journals (Sweden)

    Cheng Qu

    2015-05-01

    Full Text Available A digital file has both the content and physical information, however the latter was not fully made use of in previous digital rights management (DRM systems. This paper introduces the idea of making use of file physical information to improve the system security and provides a scheme based on this idea to resist the replay attack in DRM systems. In our scheme, compared to commonly used schemes, we remove the dependency on continuous online connection from the client-side to the server-side or the usage of tamper-proof hardware, such as Trusted Platform Module (TPM. The scheme is appropriate for offline digital content usage. Primary experiments demonstrate that our scheme is secure enough to be put into practice use.

  17. Labelling schemes: From a consumer perspective

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn; Stacey, Julia

    2000-01-01

    . A recent MAPP study has investigated the value consumers attach the Government-controlled labels 'Ø-mærket' and 'Den Blå Lup' and the private supermarket label 'Mesterhakket' when they purchase minced meat. The results reveal four consumer segments that use labelling schemes for food products very......Labelling of food products attracts a lot of political attention these days. As a result of a number of food scandals, most European countries have acknowledged the need for more information and better protection of consumers. Labelling schemes are one way of informing and guiding consumers....... However, initiatives in relation to labelling schemes seldom take their point of departure in consumers' needs and expectations; and in many cases, the schemes are defined by the institutions guaranteeing the label. It is therefore interesting to study how consumers actually value labelling schemes...

  18. A novel key management scheme using biometrics

    Science.gov (United States)

    Sui, Yan; Yang, Kai; Du, Yingzi; Orr, Scott; Zou, Xukai

    2010-04-01

    Key management is one of the most important issues in cryptographic systems. Several important challenges in such a context are represented by secure and efficient key generation, key distribution, as well as key revocation. Addressing such challenges requires a comprehensive solution which is robust, secure and efficient. Compared to traditional key management schemes, key management using biometrics requires the presence of the user, which can reduce fraud and protect the key better. In this paper, we propose a novel key management scheme using iris based biometrics. Our newly proposed scheme outperforms traditional key management schemes as well as some existing key-binding biometric schemes in terms of security, diversity and/or efficiency.

  19. On stability of difference schemes. Central schemes for hyperbolic conservation laws with source terms

    OpenAIRE

    Mond, M.; Borisov, V. S.

    2009-01-01

    The stability of difference schemes for, in general, hyperbolic systems of conservation laws with source terms are studied. The basic approach is to investigate the stability of a non-linear scheme in terms of its cor- responding scheme in variations. Such an approach leads to application of the stability theory for linear equation systems to establish stability of the corresponding non-linear scheme. It is established the notion that a non-linear scheme is stable if and only if the correspon...

  20. An Efficient and Practical Smart Card Based Anonymity Preserving User Authentication Scheme for TMIS using Elliptic Curve Cryptography.

    Science.gov (United States)

    Amin, Ruhul; Islam, S K Hafizul; Biswas, G P; Khan, Muhammad Khurram; Kumar, Neeraj

    2015-11-01

    In the last few years, numerous remote user authentication and session key agreement schemes have been put forwarded for Telecare Medical Information System, where the patient and medical server exchange medical information using Internet. We have found that most of the schemes are not usable for practical applications due to known security weaknesses. It is also worth to note that unrestricted number of patients login to the single medical server across the globe. Therefore, the computation and maintenance overhead would be high and the server may fail to provide services. In this article, we have designed a medical system architecture and a standard mutual authentication scheme for single medical server, where the patient can securely exchange medical data with the doctor(s) via trusted central medical server over any insecure network. We then explored the security of the scheme with its resilience to attacks. Moreover, we formally validated the proposed scheme through the simulation using Automated Validation of Internet Security Schemes and Applications software whose outcomes confirm that the scheme is protected against active and passive attacks. The performance comparison demonstrated that the proposed scheme has lower communication cost than the existing schemes in literature. In addition, the computation cost of the proposed scheme is nearly equal to the exiting schemes. The proposed scheme not only efficient in terms of different security attacks, but it also provides an efficient login, mutual authentication, session key agreement and verification and password update phases along with password recovery.

  1. Simulation study on the efficiencies of MOET nucleus breeding schemes applying marker assisted selection in dairy cattle

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Advantages of breeding schemes using genetic marker information and/or multiple ovulation and embryo transfer(MOET) technology over the traditional approach were extensively evaluated through simulation.Milk yield was the trait of interest and QTL was the genetic marker utilized.Eight dairy cattle breeding scenarios were considered,i.e.,traditional progeny testing breeding scheme(denoted as STANPT),GASPT scheme including a pre-selection of young bulls entering progeny testing based on their own QTL information,MOETPT scheme using MOET technology to generate young bulls and a selection of young bulls limited within the full-sib family,GAMOPT scheme adopting both QTL pre-selection and MOET technology,COMBPT scheme using a mixed linear model which considered QTL genotype instead of the BLUP model in GAMOPT,and three non-progeny testing schemes,i.e.the MOET,GAMO and COMB schemes,corresponding to MOETPT,GAMOPT and COMBPT with progeny testing being part of the system.Animals were selected based on their breeding value which was estimated under an animal model framework.Sequential selection over 17 years was performed in the simulations and 30 replicates were designed for each scenario.The influences of using QTL information and MOET technology on favorable QTL allele frequency,true breeding values,polygenetic breeding values and the accumulated genetic superiority were extensively evaluated,for five different populations including active sires,lactating cows,bull dams,bull sires,and young bulls.The results showed that the combined schemes significantly outperformed other approaches wherein accumulated true breeding value progressed.The difference between schemes exclusively using QTL information or MOET technology was not significant.The STANPT scheme was the least efficient among the 8 schemes.The schemes using MOET technology had a higher polygenetic response than others in the 17th year.The increases of frequency of the favorable QTL allele varied more greatly across

  2. Simulation study on the efficiencies of MOET nucleus breeding schemes applying marker assisted selection in dairy cattle

    Institute of Scientific and Technical Information of China (English)

    LUO WeiZhen; WANG YaChun; ZHANG Yuan

    2009-01-01

    Advantages of breeding schemes using genetic marker information and/or multiple ovulation and em-bryo transfer (MOET) technology over the traditional approach were extensively evaluated through simulation. Milk yield was the trait of interest and QTL was the genetic marker utilized. Eight dairy cattle breeding scenarios were considered, i.e., traditional progeny testing breeding scheme (denoted as STANPT), GASPT scheme including a pre-selection of young bulls entering progeny testing based on their own QTL information, MOETPT scheme using MOET technology to generate young bulls and a selection of young bulls limited within the full-sib family, GAMOPT scheme adopting both QTL pre-selection and MOET technology, COMBPT scheme using a mixed linear model which considered QTL genotype instead of the BLUP model in GAMOPT, and three non-progeny testing schemes, i.e. the MOET, GAMO and COMB schemes, corresponding to MOETPT, GAMOPT and COMBPT with progeny testing being part of the system. Animals were selected based on their breeding value which was es-timated under an animal model framework. Sequential selection over 17 years was performed in the simulations and 30 replicates were designed for each scenario. The influences of using QTL informa-tion and MOET technology on favorable QTL allele frequency, true breeding values, polygenetic breeding values and the accumulated genetic superiority were extensively evaluated, for five different populations including active sires, lactating cows, bull dams, bull sires, and young bulls. The results showed that the combined schemes significantly outperformed other approaches wherein accumulated true breeding value progressed. The difference between schemes exclusively using QTL information or MOET technology was not significant. The STANPT scheme was the least efficient among the 8 schemes. The schemes using MOET technology had a higher polygenetic response than others in the 17th year. The increases of frequency of the favorable QTL

  3. Complex Modelling Scheme Of An Additive Manufacturing Centre

    Science.gov (United States)

    Popescu, Liliana Georgeta

    2015-09-01

    This paper presents a modelling scheme sustaining the development of an additive manufacturing research centre model and its processes. This modelling is performed using IDEF0, the resulting model process representing the basic processes required in developing such a centre in any university. While the activities presented in this study are those recommended in general, changes may occur in specific existing situations in a research centre.

  4. Quality Model of Foodstuff in the Control of Refrigerated Display Cabinet

    OpenAIRE

    Cai, Junping; Risum, Jørgen; Thybo, Claus

    2006-01-01

    Commercial refrigerating systems need to be defrosted regularly to maintain a satisfactory performance. When defrosting the evaporator coil, the air temperature inside the display cabinet will increase, and float outside the normal temperature range for a period of time, the question is what happens to the food inside during this period, when we look at the quality factor?This paper discusses quality model of foodstuff, different scenarios of defrost scheme are simulated, questions such as ho...

  5. Quality Model of Foodstuff in a Refrigerated Display Cabinet

    OpenAIRE

    Cai, Junping; Risum, Jørgen; Thybo, Claus

    2006-01-01

    Commercial refrigerating systems need to be defrosted regularly to maintain a satisfactory performance. When defrosting the evaporator coil, the air temperature inside the display cabinet will increase, and float outside the normal temperature range for a period of time, the question is what happens to the food inside during this period, when we look at the quality factor?This paper discusses quality model of foodstuff, different scenarios of defrost scheme are simulated, questions such as ho...

  6. Secure Electronic Cash Scheme with Anonymity Revocation

    Directory of Open Access Journals (Sweden)

    Baoyuan Kang

    2016-01-01

    Full Text Available In a popular electronic cash scheme, there are three participants: the bank, the customer, and the merchant. First, a customer opens an account in a bank. Then, he withdraws an e-cash from his account and pays it to a merchant. After checking the electronic cash’s validity, the merchant accepts it and deposits it to the bank. There are a number of requirements for an electronic cash scheme, such as, anonymity, unforgeability, unreusability, divisibility, transferability, and portability. Anonymity property of electronic cash schemes can ensure the privacy of payers. However, this anonymity property is easily abused by criminals. In 2011, Chen et al. proposed a novel electronic cash system with trustee-based anonymity revocation from pairing. On demand, the trustee can disclose the identity for e-cash. But, in this paper we point out that Chen et al.’s scheme is subjected to some drawbacks. To contribute secure electronic cash schemes, we propose a new offline electronic cash scheme with anonymity revocation. We also provide the formally security proofs of the unlinkability and unforgeability. Furthermore, the proposed scheme ensures the property of avoiding merchant frauds.

  7. Testing hydrodynamics schemes in galaxy disc simulations

    Science.gov (United States)

    Few, C. G.; Dobbs, C.; Pettitt, A.; Konstandin, L.

    2016-08-01

    We examine how three fundamentally different numerical hydrodynamics codes follow the evolution of an isothermal galactic disc with an external spiral potential. We compare an adaptive mesh refinement code (RAMSES), a smoothed particle hydrodynamics code (SPHNG), and a volume-discretized mesh-less code (GIZMO). Using standard refinement criteria, we find that RAMSES produces a disc that is less vertically concentrated and does not reach such high densities as the SPHNG or GIZMO runs. The gas surface density in the spiral arms increases at a lower rate for the RAMSES simulations compared to the other codes. There is also a greater degree of substructure in the SPHNG and GIZMO runs and secondary spiral arms are more pronounced. By resolving the Jeans length with a greater number of grid cells, we achieve more similar results to the Lagrangian codes used in this study. Other alterations to the refinement scheme (adding extra levels of refinement and refining based on local density gradients) are less successful in reducing the disparity between RAMSES and SPHNG/GIZMO. Although more similar, SPHNG displays different density distributions and vertical mass profiles to all modes of GIZMO (including the smoothed particle hydrodynamics version). This suggests differences also arise which are not intrinsic to the particular method but rather due to its implementation. The discrepancies between codes (in particular, the densities reached in the spiral arms) could potentially result in differences in the locations and time-scales for gravitational collapse, and therefore impact star formation activity in more complex galaxy disc simulations.

  8. Different options for noble gas categorization schemes

    Science.gov (United States)

    Kalinowski, Martin

    2010-05-01

    For noble gas monitoring it is crucial to support the decision makers who need to decide whether a decection may indicate a potential nuclear test. Several parameters are available that may help to distinguish a legitimate civilian source from a nuclear explosion. The most promising parameters are: (a) Anomaly observations with respect to the history of concentrations found at that site. (b) Isotopic activity ratios can be used to separate a nuclear reactor domain from the parameter space that is specific for nuclear explosions. (c) Correlation with source-receptor-sensitivities related to known civilian sources as determined by atmospheric transport simulations. A combination of these can be used to categorize an observation. So far, several initial ideas have been presented but the issue of noble gas categorisation has been postponed with the argument that further scientific studies and additional experience have to be awaited. This paper presents the principles of different options for noble gas categorisation and considers how they would meet the interests of different classes of member states. It discusses under different points of view what might be the best approach for the noble gas categorisation scheme.

  9. A Spatial Domain Quantum Watermarking Scheme

    Science.gov (United States)

    Wei, Zhan-Hong; Chen, Xiu-Bo; Xu, Shu-Jiang; Niu, Xin-Xin; Yang, Yi-Xian

    2016-07-01

    This paper presents a spatial domain quantum watermarking scheme. For a quantum watermarking scheme, a feasible quantum circuit is a key to achieve it. This paper gives a feasible quantum circuit for the presented scheme. In order to give the quantum circuit, a new quantum multi-control rotation gate, which can be achieved with quantum basic gates, is designed. With this quantum circuit, our scheme can arbitrarily control the embedding position of watermark images on carrier images with the aid of auxiliary qubits. Besides reversely acting the given quantum circuit, the paper gives another watermark extracting algorithm based on quantum measurements. Moreover, this paper also gives a new quantum image scrambling method and its quantum circuit. Differ from other quantum watermarking schemes, all given quantum circuits can be implemented with basic quantum gates. Moreover, the scheme is a spatial domain watermarking scheme, and is not based on any transform algorithm on quantum images. Meanwhile, it can make sure the watermark be secure even though the watermark has been found. With the given quantum circuit, this paper implements simulation experiments for the presented scheme. The experimental result shows that the scheme does well in the visual quality and the embedding capacity. Supported by the National Natural Science Foundation of China under Grant Nos. 61272514, 61170272, 61373131, 61121061, 61411146001, the program for New Century Excellent Talents under Grant No. NCET-13-0681, the National Development Foundation for Cryptological Research (Grant No. MMJJ201401012) and the Fok Ying Tung Education Foundation under Grant No. 131067, and the Shandong Provincial Natural Science Foundation of China under Grant No. ZR2013FM025

  10. Consistency of non-minimal renormalisation schemes

    CERN Document Server

    Jack, I

    2016-01-01

    Non-minimal renormalisation schemes such as the momentum subtraction scheme (MOM) have frequently been used for physical computations. The consistency of such a scheme relies on the existence of a coupling redefinition linking it to MSbar. We discuss the implementation of this procedure in detail for a general theory and show how to construct the relevant redefinition up to three-loop order, for the case of a general theory of fermions and scalars in four dimensions and a general scalar theory in six dimensions.

  11. CONVERGENCE OF SUBDIVISION SCHEMES IN Lp SPACES

    Institute of Scientific and Technical Information of China (English)

    WuZhengchang

    2001-01-01

    Abstract. In this paper it is proved that Lp solutions of a refinement equation exist if and only ifthe corresponding subdivision scheme with suitable initial function converges in Lp without anyassumption on the stability of the solutions of the refinement equation. A characterization forconvergence of subdivision scheme is also given in terms of the refinement mask. Thus a com-plete answer to the relation between the existence of Lp solutions of the refinement equation andthe convergence of the corresponding subdivision schemes is given.

  12. A SUBDIVISION SCHEME FOR VOLUMETRIC MODELS

    Institute of Scientific and Technical Information of China (English)

    GhulamMustafa; LiuXuefeng

    2005-01-01

    In this paper, a subdivision scheme which generalizes a surface scheme in previous papers to volume meshes is designed. The scheme exhibits significant control over shrink-age/size of volumetric models. It also has the ability to conveniently incorporate boundaries and creases into a smooth limit shape of models. The method presented here is much simpler and easier as compared to MacCracken and Joy's. This method makes no restrictions on the local topology of meshes. Particularly, it can be applied without any change to meshes of nonmanifold topology.

  13. Cognitive radio networks dynamic resource allocation schemes

    CERN Document Server

    Wang, Shaowei

    2014-01-01

    This SpringerBrief presents a survey of dynamic resource allocation schemes in Cognitive Radio (CR) Systems, focusing on the spectral-efficiency and energy-efficiency in wireless networks. It also introduces a variety of dynamic resource allocation schemes for CR networks and provides a concise introduction of the landscape of CR technology. The author covers in detail the dynamic resource allocation problem for the motivations and challenges in CR systems. The Spectral- and Energy-Efficient resource allocation schemes are comprehensively investigated, including new insights into the trade-off

  14. Renormalization schemes: Where do we stand?

    International Nuclear Information System (INIS)

    We consider the status of the current approaches to the application of the renormalization program to the standard SU2L x U1 theory from the standpoint of the interplay of the scheme chosen for such an application and the attendant high-precision tests of the respective loop effects. We thus review the available schemes and discuss their theoretical relationships. We also show how such schemes stand in numerical relation to one another in the context of high-precision Z0 physics, as an illustration. 15 refs., 2 figs., 2 tabs

  15. TVD finite difference schemes and artificial viscosity

    Science.gov (United States)

    Davis, S. F.

    1984-01-01

    The total variation diminishing (TVD) finite difference scheme can be interpreted as a Lax-Wendroff scheme plus an upwind weighted artificial dissipation term. If a particular flux limiter is chosen and the requirement for upwind weighting is removed, an artificial dissipation term which is based on the theory of TVD schemes is obtained which does not contain any problem dependent parameters and which can be added to existing MacCormack method codes. Numerical experiments to examine the performance of this new method are discussed.

  16. Improved Quantum Signature Scheme with Weak Arbitrator

    Science.gov (United States)

    Su, Qi; Li, Wen-Min

    2013-09-01

    In this paper, we find a man-in-the-middle attack on the quantum signature scheme with a weak arbitrator (Luo et al., Int. J. Theor. Phys., 51:2135, 2012). In that scheme, the authors proposed a quantum signature based on quantum one way function which contains both verifying the signer phase and verifying the signed message phase. However, after our analysis we will show that Eve can adopt different strategies in respective phases to forge the signature without being detected. Then we present an improved scheme to increase the security.

  17. Galilean invariant resummation schemes of cosmological perturbations

    CERN Document Server

    Peloso, Marco

    2016-01-01

    Many of the methods proposed so far to go beyond Standard Perturbation Theory break invariance under time-dependent boosts (denoted here as extended Galilean Invariance, or GI). This gives rise to spurious large scale effects which spoil the small scale predictions of these approximation schemes. By using consistency relations we derive fully non-perturbative constraints that GI imposes on correlation functions. We then introduce a method to quantify the amount of GI breaking of a given scheme, and to correct it by properly tailored counterterms. Finally, we formulate resummation schemes which are manifestly GI, discuss their general features, and implement them in the so called Time-Flow, or TRG, equations.

  18. A classification scheme for chimera states

    Science.gov (United States)

    Kemeth, Felix P.; Haugland, Sindre W.; Schmidt, Lennart; Kevrekidis, Ioannis G.; Krischer, Katharina

    2016-09-01

    We present a universal characterization scheme for chimera states applicable to both numerical and experimental data sets. The scheme is based on two correlation measures that enable a meaningful definition of chimera states as well as their classification into three categories: stationary, turbulent, and breathing. In addition, these categories can be further subdivided according to the time-stationarity of these two measures. We demonstrate that this approach is both consistent with previously recognized chimera states and enables us to classify states as chimeras which have not been categorized as such before. Furthermore, the scheme allows for a qualitative and quantitative comparison of experimental chimeras with chimeras obtained through numerical simulations.

  19. Mission Mangalam scheme: Ex ploring the opportunities.

    Directory of Open Access Journals (Sweden)

    Dr. Pallavi A. Upadhyay*,

    2015-01-01

    Full Text Available Background Mission Mangalam has been launched by the Gujarat Government in 2010.It is an integrated poverty alleviation approach and an initiative to empower women. Mission Mangalam is helping women to earn their livelihood and to become independent. These Sakhimandals are linked to banks to fulfill the requirement of fund. Sakhimandals get financial assistance from banks. Some of the core benefits of the scheme can be linked with the health sector as well; Objectives (1 To review the scheme of Mission Mangalam (2 To explore the possibility of health linkage with the scheme (3 To study the perception of beneficiaries and their socio- demographic profile; Methodology: A cross sectional study. Samplesize-152 women members of Sakhimandals in Saraspur ward. Health of all the members of Mandals of Saraspur was checked by the Ahmedabad Municipal Corporation. Women of Sakhimandals were interviewed to understand their perception about the scheme as well as about any other health benefit they have experienced for themselves or their family members. 3 Additionally, Community based survey of 50 BPL families was carried out to assess the proportion of families covered under the scheme of Mission Mangalam. Results: Mean age of these women (n=152 was 31.81 years with SD=6.74. Education of maximum number 71(47% of women was up to secondary. Mean income was 5460 Rs/month with SD=1840 .Mean of number of family members is 5.4. 109 (72% women are residing in chali area. 98(64% women were told about this scheme by social worker, others were told about the scheme by her friend or UCD official. Paired t test was carried out to find increase in Hb levels of the beneficiary women. It was found to be significant (p=0.007, t=15.64. Age of women is associated with habit to save money. (p=0.003. There are only 22 (44% out of 50 families visited, who have at least one member enrolled under the scheme. More stringent efforts for universal coverage have to be made by

  20. Higher order Godunov schemes for isothermal hydrodynamics

    Science.gov (United States)

    Balsara, Dinshaw S.

    1994-01-01

    In this paper we construct higher order Godunov schemes for isothermal flow. Isothermal hydrodynamics serves as a good representation for several systems of astrophysical interest. The schemes designed here have second-order accuracy in space and time and some are third-order accurate for advection. Moreover, several ingredients of these schemes are essential components of even higher order. The methods designed here have excellent ability to represent smooth flow yet capture shocks with high resolution. Several test problems are presented. The algorithms presented here are compared with other algorithms having a comparable formal order of accuracy.

  1. Algebraic K-theory of generalized schemes

    DEFF Research Database (Denmark)

    Anevski, Stella Victoria Desiree

    Nikolai Durov has developed a generalization of conventional scheme theory in which commutative algebraic monads replace commutative unital rings as the basic algebraic objects. The resulting geometry is expressive enough to encompass conventional scheme theory, tropical algebraic geometry...... and geometry over the field with one element. It also permits the construction of important Arakelov theoretical objects, such as the completion \\Spec Z of Spec Z. In this thesis, we prove a projective bundle theorem for the eld with one element and compute the Chow rings of the generalized schemes Sp\\ec ZN......, appearing in the construction of \\Spec Z....

  2. Efficient Scheme for Entangling Two Distant Atoms

    Institute of Scientific and Technical Information of China (English)

    PING Yong-Li; LU Dao-Ming; XU Li-Xin; ZHENG Shi-Biao; CHANG Bao-Rong; LIU Hong-Ya

    2008-01-01

    A scheme is presented for the generation of entangled states for two atoms trapped in two distant cavities. In the scheme each atom is resonantly coupled with the respective cavity mode and driven by a strong classical field. The detection of a photon decaying from the cavities and passing through a beam-splitter collapses the atoms to an entangled state. The required atom-field interaction time is very short and thus the decoherence effect is suppressed. Our scheme is within the reach of presently available cavity QED techniques.

  3. Camouflage, Color Schemes, and Cubism.

    Science.gov (United States)

    Guhin, Paula

    2002-01-01

    Presents an art activity where students learn about Cubism and color mixing. Explains that the students create camouflaged animals after learning about the work, "Female Torso" (Pablo Picasso). Includes directions for how to create the pictures and states that the assignment can be used with students of all ages. (CMK)

  4. DEVELOPMENT AND APPLICATIONS OF WENO SCHEMES IN CONTINUUM PHYSICS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper briefly presents the general ideas of high order accurate weighted essentially non-oscillatory (WENO) schemes, and describes the similarities and differences of the two classes of WENO schemes: finite volume schemes and finite difference schemes. We also briefly mention a recent development of WENO schemes,namely an adaptive approach within the finite difference framework using smooth time dependent curvilinear coordinates.``

  5. Scheme of thinking quantum systems

    OpenAIRE

    V. I. YUKALOV; Sornette, D.

    2009-01-01

    A general approach describing quantum decision procedures is developed. The approach can be applied to quantum information processing, quantum computing, creation of artificial quantum intelligence, as well as to analyzing decision processes of human decision makers. Our basic point is to consider an active quantum system possessing its own strategic state. Processing information by such a system is analogous to the cognitive processes associated to decision making by humans. The algebra of p...

  6. Modified bunch filling scheme for Indus-2

    International Nuclear Information System (INIS)

    Currently Indus-2 is operated with all bunches filled mode. It may be required to fill the ring with different bunch filling patterns in future as per requirements of the users and also to mitigate the problems of ion trapping and beam instabilities. In Indus-2 one can store beam current in maximum of 291 bunches. A bunch-filling scheme has been evolved in which, it is possible to fill Indus-2 with different filling patterns. In the earlier scheme, three patterns of bunch filling are proposed namely all bunches, three symmetric bunches and a single bunch. In this scheme there is problem of bunch overlapping in the buckets, if more than one bunch is extracted from the booster. In the new scheme, a formulation has been derive to avoid the overlapping of bunches. (author)

  7. Secure Wake-Up Scheme for WBANs

    Science.gov (United States)

    Liu, Jing-Wei; Ameen, Moshaddique Al; Kwak, Kyung-Sup

    Network life time and hence device life time is one of the fundamental metrics in wireless body area networks (WBAN). To prolong it, especially those of implanted sensors, each node must conserve its energy as much as possible. While a variety of wake-up/sleep mechanisms have been proposed, the wake-up radio potentially serves as a vehicle to introduce vulnerabilities and attacks to WBAN, eventually resulting in its malfunctions. In this paper, we propose a novel secure wake-up scheme, in which a wake-up authentication code (WAC) is employed to ensure that a BAN Node (BN) is woken up by the correct BAN Network Controller (BNC) rather than unintended users or malicious attackers. The scheme is thus particularly implemented by a two-radio architecture. We show that our scheme provides higher security while consuming less energy than the existing schemes.

  8. On the Optimality of Quantum Encryption Schemes

    CERN Document Server

    Kerenidis, I; Kerenidis, Iordanis; Nagaj, Daniel

    2005-01-01

    It is known that 2 bits of entropy are necessary and sufficient to perfectly encrypt a quantum bit (quantum one-time pad). In this paper, we investigate the approximate encryption of single qubits and find the optimal trade-off between the approximation measure epsilon and the amount of classical entropy used. Then, we consider n-qubit encryption schemes which are a composition of independent single-qubit schemes. We give the optimal independent encryption scheme in the 2-norm and prove that composition in the infinity-norm is strictly worse than in the 2-norm. Last, we provide a counterexample to show that the encryption scheme of Ambainis-Smith based on small-bias sets does not work in the infinity-norm.

  9. Autonomous Droop Scheme With Reduced Generation Cost

    DEFF Research Database (Denmark)

    Nutkani, Inam Ullah; Loh, Poh Chiang; Wang, Peng;

    2014-01-01

    Droop schemes have traditionally been applied to the control of parallel synchronous generators in power systems. It has subsequently been brought over to the control of distributed generators (DGs) in microgrids with the same retained objective of proportional power sharing based on ratings....... This objective might, however, not suit microgrids well since DGs are usually of different types, unlike synchronous generators. Other factors like cost, efficiency, and emission penalty of each DG at different loading must be considered since they contribute directly to the total generation cost (TGC......) of the microgrid. To reduce this TGC without relying on fast communication links, an autonomous droop scheme is proposed here, whose resulting power sharing is decided by the individual DG generation costs. Comparing it with the traditional scheme, the proposed scheme retains its simplicity and it is hence more...

  10. Broadcast encryption schemes based on RSA

    Institute of Scientific and Technical Information of China (English)

    MU Ning-bo; HU Yu-pu; OU Hai-wen

    2009-01-01

    Three broadcast schemes for small receiver set using the property of RSA modulus are presented. They can solve the problem of data redundancy when the size of receiver set is small. In the proposed schemes, the center uses one key to encrypt the message and can revoke authorization conveniently. Every authorized user only needs to store one decryption key of a constant size. Among these three schemes, the first one has indistinguishability against adaptive chosen ciphertext attack (IND-CCA2) secure, and any collusion of authorized users cannot produce a new decryption key but the sizes of encryption modulus and ciphertext are linear in the number of receivers. In the second scheme, the size of ciphertext is half of the first one and any two authorized users can produce a new decryption key, but the center can identify them using the traitor tracing algorithm. The third one is the most efficient but the center cannot identify the traitors exactly.

  11. Lifting scheme of symmetric tight wavelets frames

    Institute of Scientific and Technical Information of China (English)

    ZHUANG BoJin; YUAN WeiTao; PENG LiZhong

    2008-01-01

    This paper proposes a method to realize the lifting scheme of tight frame wavelet filters. As for 4-channel tight frame wavelet filter, the tight frame transforms' ma-trix is 2×4, but the lifting scheme transforms' matrix must be 4×4. And in the case of 3-channel tight frame wavelet filter, the transforms' matrix is 2×3, but the lifting scheme transforms' matrix must be 3×3. In order to solve this problem, we intro-duce two concepts: transferred polyphase matrix for 4-channel filters and trans-ferred unitary matrix for 3-channel filters. The transferred polyphase matrix is sym-metric/antisymmetric. Thus, we use this advantage to realize the lifting scheme.

  12. Certificateless universal designated verifier signature schemes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Universal designated verifier signature schemes allows a signature holder to designate the signature to a desire designated verifier, in such a way that only designated verifier can verify this signature, but is unable to convince anyone else of this fact.The previous constructions of universal designated verifier signature rely on the underlying public key infrastructure, that needs both signers and verifiers to verify the authenticity of the public keys, and hence, the certificates are required.This article presents the first model and construction of the certificateless universal designated verifier signature scheme, in which the certificates are not needed.The proposed scheme satisfies all the requirements of the universal designated verifier signature in the certificateless system.Security proofs are provided for the scheme based on the random oracle model, assuming that the Bilinear diffie-hellman (BDH) problem is hard to solve.

  13. The Effective Key Length of Watermarking Schemes

    CERN Document Server

    Bas, Patrick

    2012-01-01

    Whereas the embedding distortion, the payload and the robustness of digital watermarking schemes are well understood, the notion of security is still not completely well defined. The approach proposed in the last five years is too theoretical and solely considers the embedding process, which is half of the watermarking scheme. This paper proposes a new measurement of watermarking security, called the effective key length, which captures the difficulty for the adversary to get access to the watermarking channel. This new methodology is applied to additive spread spectrum schemes where theoretical and practical computations of the effective key length are proposed. It shows that these schemes are not secure as soon as the adversary gets observations in the Known Message Attack context.

  14. A lightweight authentication scheme with user untraceability

    Institute of Scientific and Technical Information of China (English)

    Kuo-Hui YEH

    2015-01-01

    With the rapid growth of electronic commerce and associated demands on variants of Internet based applications, application systems providing network resources and business services are in high demand around the world. To guarantee ro-bust security and computational efficiency for service retrieval, a variety of authentication schemes have been proposed. How-ever, most of these schemes have been found to be lacking when subject to a formal security analysis. Recently, Changet al. (2014) introduced a formally provable secure authentication protocol with the property of user-untraceability. Unfortunately, based on our analysis, the proposed scheme fails to provide the property of user-untraceability as claimed, and is insecure against user impersonation attack, server counterfeit attack, and man-in-the-middle attack. In this paper, we demonstrate the details of these malicious attacks. A security enhanced authentication scheme is proposed to eliminate all identified weaknesses.

  15. A New Efficient Mobile Micropayment Scheme

    Institute of Scientific and Technical Information of China (English)

    FU Xiong; YANG Zong-kai; LANG Wei-min; TAN Yun-meng

    2004-01-01

    This paper proposes a micropayment scheme designed for GSM mobile scenario, where the overload of computation, storage and communication for mobile phone is reduced by directing operations normally performed by the mobile user to the static portion of the network in view of its limited capability. Messages which received and sent during the payment are very simple and public key infrastructure is not needed, which reduces delay and removes the possibility of incomplete payment due to communications failures. Furthermore, all the information related to payment is encrypted by a shared symmetric key in our scheme, so the privacy of the mobile user is protected and the security of information is guaranteed. Compared with other mobile micropayment schemes in existence, no public-key operation is required, which minimizes the computation and storage overhead dramatically. In addition, restricted anonymous is also provided in our scheme.

  16. Twin-Schnorr: a security upgrade for the Schnorr identity-based identification scheme.

    Science.gov (United States)

    Chin, Ji-Jian; Tan, Syh-Yuan; Heng, Swee-Huay; Phan, Raphael Chung-Wei

    2015-01-01

    Most identity-based identification (IBI) schemes proposed in recent literature are built using pairing operations. This decreases efficiency due to the high operation costs of pairings. Furthermore, most of these IBI schemes are proven to be secure against impersonation under active and concurrent attacks using interactive assumptions such as the one-more RSA inversion assumption or the one-more discrete logarithm assumption, translating to weaker security guarantees due to the interactive nature of these assumptions. The Schnorr-IBI scheme was first proposed through the Kurosawa-Heng transformation from the Schnorr signature. It remains one of the fastest yet most secure IBI schemes under impersonation against passive attacks due to its pairing-free design. However, when required to be secure against impersonators under active and concurrent attacks, it deteriorates greatly in terms of efficiency due to the protocol having to be repeated multiple times. In this paper, we upgrade the Schnorr-IBI scheme to be secure against impersonation under active and concurrent attacks using only the classical discrete logarithm assumption. This translates to a higher degree of security guarantee with only some minor increments in operational costs. Furthermore, because the scheme operates without pairings, it still retains its efficiency and superiority when compared to other pairing-based IBI schemes. PMID:25692179

  17. Twin-Schnorr: A Security Upgrade for the Schnorr Identity-Based Identification Scheme

    Directory of Open Access Journals (Sweden)

    Ji-Jian Chin

    2015-01-01

    Full Text Available Most identity-based identification (IBI schemes proposed in recent literature are built using pairing operations. This decreases efficiency due to the high operation costs of pairings. Furthermore, most of these IBI schemes are proven to be secure against impersonation under active and concurrent attacks using interactive assumptions such as the one-more RSA inversion assumption or the one-more discrete logarithm assumption, translating to weaker security guarantees due to the interactive nature of these assumptions. The Schnorr-IBI scheme was first proposed through the Kurosawa-Heng transformation from the Schnorr signature. It remains one of the fastest yet most secure IBI schemes under impersonation against passive attacks due to its pairing-free design. However, when required to be secure against impersonators under active and concurrent attacks, it deteriorates greatly in terms of efficiency due to the protocol having to be repeated multiple times. In this paper, we upgrade the Schnorr-IBI scheme to be secure against impersonation under active and concurrent attacks using only the classical discrete logarithm assumption. This translates to a higher degree of security guarantee with only some minor increments in operational costs. Furthermore, because the scheme operates without pairings, it still retains its efficiency and superiority when compared to other pairing-based IBI schemes.

  18. Sellafield site (including Drigg) emergency scheme manual

    International Nuclear Information System (INIS)

    This Emergency Scheme defines the organisation and procedures available should there be an accident at the Sellafield Site which results in, or may result in, the release of radioactive material, or the generation of a high radiation field, which might present a hazard to employees and/or the general public. This manual covers the general principles of the total emergency scheme and those detailed procedures which are not specific to any single department. (U.K.)

  19. Splitting schemes for poroelasticity and thermoelasticity problems

    OpenAIRE

    Kolesov, A. E.; Vabishchevich, P. N.; Vasilyeva, M. V.

    2013-01-01

    In this work, we consider the coupled systems of linear unsteady partial differential equations, which arise in the modeling of poroelasticity processes. Stability estimates of weighted difference schemes for the coupled system of equations are presented. Approximation in space is based on the finite element method. We construct splitting schemes and give some numerical comparisons for typical poroelasticity problems. The results of numerical simulation of a 3D problem are presented. Special ...

  20. A comparison of ENO and TVD schemes

    Science.gov (United States)

    Chang, Shih-Hung; Liou, Meng-Sing

    1988-01-01

    The numerical performance of a second-order upwind-based TVD scheme is compared with that of a uniform second-order ENO scheme on shock capturing. The cases considered include flows with Mach numbers of 2.9, 5.0, and 10.0. For cases with Mach numbers of 5.0 and 10.0, the computed ENO results are inferior to the corresponding TVD results.

  1. On nonstandard finite difference schemes in biosciences

    Science.gov (United States)

    Anguelov, R.; Dumont, Y.; Lubuma, J. M.-S.

    2012-10-01

    We design, analyze and implement nonstandard finite difference (NSFD) schemes for some differential models in biosciences. The NSFD schemes are reliable in three directions. They are topologically dynamically consistent for onedimensional models. They can replicate the global asymptotic stability of the disease-free equilibrium of the MSEIR model in epidemiology whenever the basic reproduction number is less than 1. They preserve the positivity and boundedness property of solutions of advection-reaction and reaction-diffusion equations.

  2. AI & Law, logic and argument schemes

    OpenAIRE

    Prakken, Henry

    2006-01-01

    This paper reviews the history of AI & Law research from the perspective of argument schemes. It starts with the observation that logic, although very well applicable to legal reasoning when there is uncertainty, vagueness and disagreement, is too abstract to give a fully satisfactory classification of legal argument types. It therefore needs to be supplemented with an argument-scheme approach, which classifies arguments not according to their logical form but according to their content, in p...

  3. A classification scheme for chimera states

    OpenAIRE

    Kemeth, Felix P.; Haugland, Sindre W.; Schmidt, Lennart; Kevrekidis, Ioannis G.; Krischer, Katharina

    2016-01-01

    We present a universal characterization scheme for chimera states applicable to both numerical and experimental data sets. The scheme is based on two correlation measures that enable a meaningful definition of chimera states as well as their classification into three categories: stationary, turbulent and breathing. In addition, these categories can be further subdivided according to the time-stationarity of these two measures. We demonstrate that this approach both is consistent with previous...

  4. Basis scheme of personnel training system

    International Nuclear Information System (INIS)

    Basic scheme of the training system for NPP personnel of CEZ-EDU personnel training system is described in detail. This includes: specific training both basic and periodic, and professional training meaning specialized and continuous training. The following schemes are shown: licence acquisition and authorisation for PWR-440 Control Room Personnel; upgrade training for job positions of Control Room personnel; maintaining and refresh training; module training for certificate acquisition of servicing shift and operating personnel

  5. A modified scheme for biotyping Gardnerella vaginalis.

    Science.gov (United States)

    Benito, R; Vazquez, J A; Berron, S; Fenoll, A; Saez-Neito, J A

    1986-06-01

    A scheme is proposed for biotyping Gardnerella vaginalis, based on detection of hippurate hydrolysis, beta-galactosidase (ONPG) and lipase, and fermentation of arabinose, galactose and xylose. Seventeen biotypes were found among 197 strains from asymptomatic women and patients with bacterial vaginosis (non-specific vaginitis). The distribution of biotypes was similar in both populations but some biotypes were found more frequently in patients. The proposed scheme is compared with those previously described.

  6. A networked registration scheme for enhancing trust

    OpenAIRE

    Pickering, J Adrian; Gutteridge, Christopher

    2009-01-01

    Society has widely adopted use of electronic data without sufficient attention to the problems of non-repudiation (NR). A universal, transparent scheme is needed to replace the traditional paper-based model that people are familiar with. A registration scheme is proposed that uses a network of registration servers run in a way that is robust to legal and technical challenge. Any user can register potential electronic evidence with one or more of these servers. This enables a user to later ass...

  7. Renormalization Scheme Dependence and Renormalization Group Summation

    CERN Document Server

    McKeon, D G C

    2016-01-01

    We consider logarithmic contributions to the free energy, instanton effective action and Laplace sum rules in QCD that are a consequence of radiative corrections. Upon summing these contributions by using the renormalization group, all dependence on the renormalization scale parameter mu cancels. The renormalization scheme dependence in these processes is examined, and a renormalization scheme is found in which the effect of higher order radiative corrections is absorbed by the behaviour of the running coupling.

  8. An Instability of the Godunov Scheme

    OpenAIRE

    Bressan, Alberto; Jenssen, Helge Kristian; Baiti, Paolo

    2005-01-01

    We construct a solution to a $2\\times 2$ strictly hyperbolic system of conservation laws, showing that the Godunov scheme \\cite{Godunov59} can produce an arbitrarily large amount of oscillations. This happens when the speed of a shock is close to rational, inducing a resonance with the grid. Differently from the Glimm scheme or the vanishing viscosity method, for systems of conservation laws our counterexample indicates that no a priori BV bounds or $L^1$ stability estimates can in general be...

  9. Electronic Payment Scheme to Prevent the Treachery

    Institute of Scientific and Technical Information of China (English)

    FAN Kai; ZHANG Jun; KOU Weidong; XIAO Guozhen

    2006-01-01

    Treachery is one of the restrictions to the development of electronic commerce. To prevent the treachery from the participants in electronic commerce, in this paper a secure electronic payment scheme is proposed and its security is analyzed. This scheme can prevent the treachery only with the aid of an un-trusted third party. It is very simple and it also improves the security and provides the non-repudiation, accountability, fairness and privacy.

  10. The AGROVOC Concept Scheme : A Walkthrough

    OpenAIRE

    Rajbhandari, Sachit; Keizer, Johannes

    2012-01-01

    The Food and Agriculture Organization is developing a concept based multilingual vocabulary management tool to manage thesauri, authority lists and glossaries expressed as concept schemes ready to be used in a linked data environment. In this paper, we described the evolution of the AGROVOC thesaurus to AGROVOC Concept Scheme based on OWL (web ontology language) model and now shifting to SKOS (simple knowledge organization system) model. The paper explained why and how it evolved ...

  11. Binary Schemes of Vapor Bubble Growth

    Science.gov (United States)

    Zudin, Yu. B.

    2015-05-01

    A problem on spherically symmetric growth of a vapor bubble in an infi nite volume of a uniformly superheated liquid is considered. A description of the limiting schemes of bubble growth is presented. A binary inertial-thermal bubble growth scheme characterized by such specifi c features as the "three quarters" growth law and the effect of "pressure blocking" in a vapor phase is considered.

  12. Traffic calming schemes : opportunities and implementation strategies.

    OpenAIRE

    Schagen, I.N.L.G. van (samenst.)

    2003-01-01

    Commissioned by the Swedish National Road Authority, this report aims to provide a concise overview of knowledge of and experiences with traffic calming schemes in urban areas, both on a technical level and on a policy level. Traffic calming refers to a combination of network planning and engineering measures to enhance road safety as well as other aspects of liveability for the citizens. More specifically, in the current report the starting point is that traffic calming schemes in residentia...

  13. Simplification of the unified gas kinetic scheme.

    Science.gov (United States)

    Chen, Songze; Guo, Zhaoli; Xu, Kun

    2016-08-01

    The unified gas kinetic scheme (UGKS) is an asymptotic preserving (AP) scheme for kinetic equations. It is superior for transition flow simulation and has been validated in the past years. However, compared to the well-known discrete ordinate method (DOM), which is a classical numerical method solving the kinetic equations, the UGKS needs more computational resources. In this study, we propose a simplification of the unified gas kinetic scheme. It allows almost identical numerical cost as the DOM, but predicts numerical results as accurate as the UGKS. In the simplified scheme, the numerical flux for the velocity distribution function and the numerical flux for the macroscopic conservative quantities are evaluated separately. The equilibrium part of the UGKS flux is calculated by analytical solution instead of the numerical quadrature in velocity space. The simplification is equivalent to a flux hybridization of the gas kinetic scheme for the Navier-Stokes (NS) equations and the conventional discrete ordinate method. Several simplification strategies are tested, through which we can identify the key ingredient of the Navier-Stokes asymptotic preserving property. Numerical tests show that, as long as the collision effect is built into the macroscopic numerical flux, the numerical scheme is Navier-Stokes asymptotic preserving, regardless the accuracy of the microscopic numerical flux for the velocity distribution function. PMID:27627418

  14. Simplification of the unified gas kinetic scheme

    Science.gov (United States)

    Chen, Songze; Guo, Zhaoli; Xu, Kun

    2016-08-01

    The unified gas kinetic scheme (UGKS) is an asymptotic preserving (AP) scheme for kinetic equations. It is superior for transition flow simulation and has been validated in the past years. However, compared to the well-known discrete ordinate method (DOM), which is a classical numerical method solving the kinetic equations, the UGKS needs more computational resources. In this study, we propose a simplification of the unified gas kinetic scheme. It allows almost identical numerical cost as the DOM, but predicts numerical results as accurate as the UGKS. In the simplified scheme, the numerical flux for the velocity distribution function and the numerical flux for the macroscopic conservative quantities are evaluated separately. The equilibrium part of the UGKS flux is calculated by analytical solution instead of the numerical quadrature in velocity space. The simplification is equivalent to a flux hybridization of the gas kinetic scheme for the Navier-Stokes (NS) equations and the conventional discrete ordinate method. Several simplification strategies are tested, through which we can identify the key ingredient of the Navier-Stokes asymptotic preserving property. Numerical tests show that, as long as the collision effect is built into the macroscopic numerical flux, the numerical scheme is Navier-Stokes asymptotic preserving, regardless the accuracy of the microscopic numerical flux for the velocity distribution function.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-02-01

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

  16. A NEW SCHEME BASED ON THE MI SCHEME AND ITS ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    Jiao Luyao; Li Yifa; Qiao Shuaiting

    2013-01-01

    This article aims at designing a new Multivariate Quadratic (MQ) public-key scheme to avoid the linearization attack and differential attack against the Matsumoto-Imai (MI) scheme.Based on the original scheme,our new scheme,named the Multi-layer MI (MMI) scheme,has a structure of multi-layer central map.Firstly,this article introduces the MI scheme and describes linearization attack and differential attack; then prescribes the designation of MMI in detail,and proves that MMI can resist both linearization attack and differential attack.Besides,this article also proves that MMI can resist recent eXtended Linearization (XL)-like methods.In the end,this article concludes that MMI also maintains the efficiency of MI.

  17. Sustitución del descongelante sintético de semen por leche de vaca para la inseminación de hembras bovinas - Substitution of the defrost of synthetic semen for milk of it vacates for the insemination of bovine females

    Directory of Open Access Journals (Sweden)

    Botello A. R.

    2011-01-01

    Full Text Available ResumenEl presente trabajo propone sustituir el descongelante sintético para semen bovino (DSSB por leche de vaca, como opción sostenible en los programas de inseminación artificial (IA de las hembras bovinas. Por un período de cuatro años (2005 - 2008 se investigaron 780 animales del cruce (Holstein x Cebú con condición corporal mayor e igual a 3,5 y se conformaron dos tratamientos, cada uno compuesto por 390 animales, al primer grupo se le aplicó IA con DSBS y al segundo con leche de vaca, a los que se les midió: la proporción de gestación y nacimientos. Las proporciones fueron comparadas por una prueba de hipótesis de Z.SummaryThe present work intends to substitute the defrost of synthetic bovine semen (DSBS for cow milk, as sustainable alternative in the programs of artificial insemination (AI of the bovine females. For a four year period (2005-2008 780 animals of the cross-breed (Holstein x Cebú were investigated with more corporal condition and similar to 3,5 and they conformed to two treatments, each one composed by 390 animals, to the first group was applied AI with DSBS and a second with cow milk, to those that were measured: the gestation proportion and births. The proportions were compared by a test of hypothesis of Z.

  18. Modelling of Substrate Noise and Mitigation Schemes for UWB Systems

    DEFF Research Database (Denmark)

    Shen, Ming; Mikkelsen, Jan H.; Larsen, Torben

    2012-01-01

    The last chapter of this first part of the book, chapter seven, is devoted to Modeling of Substrate Noise and Mitigation Schemes for Ultrawideband (UWB) systems, and is written by Ming Shen, Jan H. Mikkelsen, and Torben Larsen from Aalborg University, Denmark. In highly integrated mixed...... with narrow-band circuits. This chapter presents a study on the modeling and mitigation of substrate noise in mixed-signal integrated circuits (ICs), focusing on UWB system/circuit designs. Experimental impact evaluation of substrate noise on UWB circuits is presented. It shows how a wide-band circuit can...... be affected by substrate noise. This chapter also presents a new analytical model for the estimation of the spectral content of the switching noise. In addition a novel active noise mitigation scheme based on spectral information is presented....

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

    OpenAIRE

    Caprio, M. A.

    2005-01-01

    LevelScheme is a scientific figure preparation system for Mathematica. The main emphasis is upon the construction of level schemes, or level energy diagrams, as used in nuclear, atomic, molecular, and hadronic physics. LevelScheme also provides a general infrastructure for the preparation of publication-quality figures, including support for multipanel and inset plotting, customizable tick mark generation, and various drawing and labeling tasks. Coupled with Mathematica's plotting functions a...

  20. Scheme to Implement Scheme 1 → M Economical Phase-Covariant Telecloning via Cavity QED

    Institute of Scientific and Technical Information of China (English)

    LIU Qi; ZHANG Wen-Hai; YE Liu

    2008-01-01

    We propose an experimentally feasible scheme to implement the economical 1 → M(M = 2k + 1) phase-covariant telecloning without ancilla based on cavity QED. The scheme requires cavity-assisted collision processes between atoms, which cross through the off-resonant cavity field in the vacuum states. During the telecloning process, the cavity is only virtually excited and it thus greatly prolongs the efficient decoherent time. Therefore, our scheme may be realized in experiment in future.

  1. Cryptanalysis and Improvement of Piveteau Signature Scheme with Message Recovery

    Institute of Scientific and Technical Information of China (English)

    李子臣; 成军祥; 戴一奇

    2003-01-01

    Piveteau signature scheme allows message recovery but the methodology differs from that of the Nyberg-Rueppel schemes. This paper analyzes the security of the Piveteau scheme by designing some attacks. Two improved methods to Piveteau signature scheme and Nyberg-Rueppel schemes were developed to avoid these weaknesses. Analyses of the security of the improved schemes prove that the improved methods can effectively handle the attacks proposed in this paper.

  2. 臭氧-生物活性炭工艺设计中工程方案的选择%Selection of Engineering Scheme in Ozone/Biological Activated Carbon Process Design

    Institute of Scientific and Technical Information of China (English)

    李世峰

    2012-01-01

    Ozone/biological activated carbon ( O3/BAC ) process was developed on the basis of biological activated carbon process, which is recognized as one of the most effective advanced treatment processes in removing organic pollutants and odor from drinking water in the world at present. With the implementation of the Standards for Drinking Water Quality ( GB 5749 - 2006 ) , O3/BAC process has been widely used in upgrading and reconstruction of water treatment plants. In the design, selection of gas source for ozone generator and design of activated carbon tank type related to project investment, operation cost and operation management. In order to facilitate the upgrading and reconstruction project of water treatment plants, it needs to choose the ozone source and tank type reasonably according to the actual situation of the plant.%臭氧-生物活性炭(O3-BAC)工艺是在生物活性炭工艺基础上发展起来的,是目前世界上公认的去除饮用水中有机污染物、嗅味等较为有效的深度处理工艺之一.随着《生活饮用水卫生标准》( GB 5749-2006)的实施,臭氧-生物活性炭工艺广泛应用于给水厂的提标改造中.在其设计中,臭氧气源的选择和活性炭池池型的设计关系到工程的投资、运行成本的高低以及操作管理的难易,需根据各给水厂的实际情况,合理选择臭氧气源和活性炭池池型,以利于给水厂提标改造工程的实施.

  3. Feasibility analysis of two identity- based proxy ring signature schemes

    Institute of Scientific and Technical Information of China (English)

    Wang Huaqun; Zhang Lijun; Zhao Junxi

    2007-01-01

    Recently , proxy ring signature schemes have been shown to be useful in various applications , such as electronic polling, electronic payment, etc. Although many proxy ring signature schemes have been proposed, there are only two identity- based proxy ring signature schemes have been proposed until now, I.e., Cheng's scheme and Lang's scheme. It's unlucky that the two identity- based proxy ring signature schemes are unfeasible . This paper points out the reasons why the two identity- based proxy ring signature schemes are unfeasible. In order to design feasible and efficient identity-based proxy ring signature schemes from bilinear pairings , we have to search for other methods .

  4. Combining image-processing and image compression schemes

    Science.gov (United States)

    Greenspan, H.; Lee, M.-C.

    1995-01-01

    An investigation into the combining of image-processing schemes, specifically an image enhancement scheme, with existing compression schemes is discussed. Results are presented on the pyramid coding scheme, the subband coding scheme, and progressive transmission. Encouraging results are demonstrated for the combination of image enhancement and pyramid image coding schemes, especially at low bit rates. Adding the enhancement scheme to progressive image transmission allows enhanced visual perception at low resolutions. In addition, further progressing of the transmitted images, such as edge detection schemes, can gain from the added image resolution via the enhancement.

  5. Identification Schemes from Key Encapsulation Mechanisms

    Science.gov (United States)

    Anada, Hiroaki; Arita, Seiko

    We propose a generic conversion from a key encapsulation mechanism (KEM) to an identification (ID) scheme. The conversion derives the security for ID schemes against concurrent man-in-the-middle (cMiM) attacks from the security for KEMs against adaptive chosen ciphertext attacks on one-wayness (one-way-CCA2). Then, regarding the derivation as a design principle of ID schemes, we develop a series of concrete one-way-CCA2 secure KEMs. We start with El Gamal KEM and prove it secure against non-adaptive chosen ciphertext attacks on one-wayness (one-way-CCA1) in the standard model. Then, we apply a tag framework with the algebraic trick of Boneh and Boyen to make it one-way-CCA2 secure based on the Gap-CDH assumption. Next, we apply the CHK transformation or a target collision resistant hash function to exit the tag framework. And finally, as it is better to rely on the CDH assumption rather than the Gap-CDH assumption, we apply the Twin DH technique of Cash, Kiltz and Shoup. The application is not “black box” and we do it by making the Twin DH technique compatible with the algebraic trick. The ID schemes obtained from our KEMs show the highest performance in both computational amount and message length compared with previously known ID schemes secure against concurrent man-in-the-middle attacks.

  6. Short-Term Saved Leave Scheme

    CERN Multimedia

    2007-01-01

    As announced at the meeting of the Standing Concertation Committee (SCC) on 26 June 2007 and in http://Bulletin No. 28/2007, the existing Saved Leave Scheme will be discontinued as of 31 December 2007. Staff participating in the Scheme will shortly receive a contract amendment stipulating the end of financial contributions compensated by save leave. Leave already accumulated on saved leave accounts can continue to be taken in accordance with the rules applicable to the current scheme. A new system of saved leave will enter into force on 1 January 2008 and will be the subject of a new implementation procedure entitled "Short-term saved leave scheme" dated 1 January 2008. At its meeting on 4 December 2007, the SCC agreed to recommend the Director-General to approve this procedure, which can be consulted on the HR Department’s website at the following address: https://cern.ch/hr-services/services-Ben/sls_shortterm.asp All staff wishing to participate in the new scheme a...

  7. Short-Term Saved Leave Scheme

    CERN Multimedia

    HR Department

    2007-01-01

    As announced at the meeting of the Standing Concertation Committee (SCC) on 26 June 2007 and in http://Bulletin No. 28/2007, the existing Saved Leave Scheme will be discontinued as of 31 December 2007. Staff participating in the Scheme will shortly receive a contract amendment stipulating the end of financial contributions compensated by save leave. Leave already accumulated on saved leave accounts can continue to be taken in accordance with the rules applicable to the current scheme. A new system of saved leave will enter into force on 1 January 2008 and will be the subject of a new im-plementation procedure entitled "Short-term saved leave scheme" dated 1 January 2008. At its meeting on 4 December 2007, the SCC agreed to recommend the Director-General to approve this procedure, which can be consulted on the HR Department’s website at the following address: https://cern.ch/hr-services/services-Ben/sls_shortterm.asp All staff wishing to participate in the new scheme ...

  8. Simple theory for designing tidal power schemes

    Science.gov (United States)

    Prandle, D.

    Basic parameters governing the design of tidal power schemes are identified and converted to dimensionless form by reference to (i) the mean tidal range and (ii) the surface area of the enclosed basin. Optimum values for these dimensionless parameters are derived and comparison made with actual engineering designs. A theoretical framework is thus established which can be used (i) to make a rudimentary design at any specific location or (ii) to compare and evaluate designs for various locations. Both one-way (flood or ebb) and two-way (flood and ebb) schemes are examined and, theoretically, the two-way scheme is shown to be more efficient. However, in practice, two-way schemes suffer disadvantages arising from (i) two-way flow through both turbines and sluices and (ii) lower average turbine heads. An important dimensional aspect of tidal power schemes is that, while energy extracted is proportional to the tidal amplitude squared, the requisite sluicing area is proportional to the square root of the tidal amplitude. In consequence, sites with large tidal amplitudes are best suited to tidal power development whereas for sites with low tidal amplitudes sluicing costs may be prohibitive.

  9. Dynamic Localization Schemes in Malicious Sensor Networks

    Directory of Open Access Journals (Sweden)

    Kaiqi Xiong

    2009-10-01

    Full Text Available Wireless sensor networks (WSN have recently shown many potential military and civilian applications, especially those used in hostile environments where malicious adversaries can be present. The accuracy of location information is critical for such applications. It is impractical to have a GPS device on each sensor in WSN due to costs. Most of the existing location discovery schemes can only be used in the trusted environment. Recent research has addressed security issues in sensor network localization, but to the best of our knowledge, none have completely solved the secure localization problem. In this paper, we propose novel schemes for secure dynamic localization in sensor networks. These proposed schemes can tolerate up to 50% of beacon nodes being malicious, and they have linear computation time with respect to the number of reference nodes. Our security analysis has showed that our schemes are applicable and resilient to attacks from adversaries. We have further conducted simulations to analyze and compare the performance of these schemes, and to indicate when each should be used. The efficiencies of each method shows why we needed to propose multiple methods.

  10. Financial incentive schemes in primary care

    Directory of Open Access Journals (Sweden)

    Gillam S

    2015-09-01

    Full Text Available Stephen Gillam Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge, Cambridge, UK Abstract: Pay-for-performance (P4P schemes have become increasingly common in primary care, and this article reviews their impact. It is based primarily on existing systematic reviews. The evidence suggests that P4P schemes can change health professionals' behavior and improve recorded disease management of those clinical processes that are incentivized. P4P may narrow inequalities in performance comparing deprived with nondeprived areas. However, such schemes have unintended consequences. Whether P4P improves the patient experience, the outcomes of care or population health is less clear. These practical uncertainties mirror the ethical concerns of many clinicians that a reductionist approach to managing markers of chronic disease runs counter to the humanitarian values of family practice. The variation in P4P schemes between countries reflects different historical and organizational contexts. With so much uncertainty regarding the effects of P4P, policy makers are well advised to proceed carefully with the implementation of such schemes until and unless clearer evidence for their cost–benefit emerges. Keywords: financial incentives, pay for performance, quality improvement, primary care

  11. Effects of small irrigation schemes in farm resource production and climate change adaptation practices in Nepal

    Directory of Open Access Journals (Sweden)

    Kabi Prasad Pokhrel

    2013-04-01

    Full Text Available This paper is an attempt to evaluate the socio-economic as well as environmental impacts of small irrigation schemes in different parts of Nepal so as to help in formulating future policies on small irrigation schemes and subsidy programs. The paper has clearly pointed out the operation and management structure in each of the selected schemes have been playing significant role to increase the farm resource productivity, reduce poverty level, improve farmer participation and to manage available environmental resources in sustainable way. Furthermore, the functions and effectiveness of the Irrigation Management Committees (IMCs and Water Users Groups (WUGs, farmers groups (FG and cooperatives have been actively participated in the overall activities of small scale irrigation schemes to implement effectively.

  12. Arbitrated quantum signature schemes without using entangled states

    CERN Document Server

    Zou, Xiangfu

    2010-01-01

    A digital signature is a mathematical scheme for demonstrating the authenticity of a digital message or document. For signing quantum messages, some arbitrated quantum signature schemes have being proposed. However, in the existing literature, arbitrated quantum signature schemes depend on entanglement. In this paper, we present two arbitrated quantum signature schemes without utilizing entangled states in the signing phase and the verifying phase. The first proposed scheme can preserve the merits in the existing schemes. Then, we point out, in this scheme and the prior schemes, there exists a problem that Bob can repudiate the integrality of the signatures. To conquer this problem, we construct another arbitrated quantum signature scheme without using quantum entangled states but using a public board. The new scheme has three advantages: it does not utilize entangled states while it can preserve all merits in the existing schemes; the integrality of the signature can avoid being disavowed by the receiver; an...

  13. Multi-Level Secret Sharing Scheme for Mobile Ad-Hoc Networks

    Directory of Open Access Journals (Sweden)

    P.V. Siva Kumar

    2015-09-01

    Full Text Available In this paper, we are concerned with security for Mobile Ad-hoc Networks (MANETs using threshold cryptography. When we are applying cryptography to MANETs, key management schemes must provide the cryptographic keys in a secure manner and storing the secret information within the nodes, thwarting the activities of malicious nodes inside a network and is how to distribute the role of the trusted authority among the nodes. Mobile ad hoc networks (MANETs represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, ad-hoc network topologies. Secret Sharing Scheme is a method which distributes shares of a secret to a set of participants in such a way that only authorized subset of participants can uniquely reconstruct the secret and an unauthorized subset can get no information about the secret. In this paper we present a new multilevel secret sharing scheme by extending the Shamir’s to the case that the global threshold is strictly greater than the sum of the compartment thresholds and we indicate how to use the threshold secret sharing schemes based on polynomial interpolation. These schemes are based on one-way functions (Discrete Logarithm which are computationally perfect. In the first scheme the number of public shares grows exponentially with the number of participants. To overcome this disadvantage we proposed two efficient schemes in which the number of public shares ate linearly proportional to the number of participants. Both these schemes are similar except that in the third scheme the identities of the participants are also hidden. In this we also addressed the problem of malicious shareholders that aim to corrupt a secret sharing scheme. To prevent such a threat, legitimate shareholders must detect any modification of shares that has not been issued by a node responsible for the sharing of secret S.

  14. Compression scheme for geophysical electromagnetic inversions

    Science.gov (United States)

    Abubakar, A.

    2014-12-01

    We have developed a model-compression scheme for improving the efficiency of the regularized Gauss-Newton inversion algorithm for geophysical electromagnetic applications. In this scheme, the unknown model parameters (the conductivity/resistivity distribution) are represented in terms of a basis such as Fourier and wavelet (Haar and Daubechies). By applying a truncation criterion, the model may then be approximated by a reduced number of basis functions, which is usually much less than the number of the model parameters. Further, because the geophysical electromagnetic measurements have low resolution, it is sufficient for inversion to only keep the low-spatial frequency part of the image. This model-compression scheme accelerates the computational time and also reduces the memory usage of the Gauss-Newton method. We are able to significantly reduce the algorithm computational complexity without compromising the quality of the inverted models.

  15. COPROX fixed bed reactor - temperature control schemes

    Energy Technology Data Exchange (ETDEWEB)

    Giunta, P.; Moreno, M.; Marino, F.; Amadeo, N.; Lobarde, M. [Laboratorio de Procesos Cataliticos, Facultad de Ingenieria, Universidad de Buenos Aires, Buenos Aires (Argentina)

    2012-06-15

    Different temperature control schemes for the COPROX stage of a 5-kW fuel cell system were analyzed. It was found that, among the schemes proposed, i.e., co- and countercurrent heat exchange, single adiabatic reactor and series of adiabatic reactors with interstage heat exchange, the best choice for temperature control was the series of adiabatic reactors with interstage heat exchange. This scheme represented the best way to keep the average temperature around 443 K, which was found to be the most suitable temperature for selectivity towards CO oxidation. If hydrogen is produced from ethanol steam reforming, the heat withdrawal can be carried out by the water/ethanol reformer feed mixture, thus contributing to the energy integration of the overall system. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. An ECC-Based Blind Signature Scheme

    Directory of Open Access Journals (Sweden)

    Fuh-Gwo Jeng

    2010-08-01

    Full Text Available Cryptography is increasingly applied to the E-commerce world, especially to the untraceable payment system and the electronic voting system. Protocols for these systems strongly require the anonymous digital signature property, and thus a blind signature strategy is the answer to it. Chaum stated that every blind signature protocol should hold two fundamental properties, blindness and intractableness. All blind signature schemes proposed previously almost are based on the integer factorization problems, discrete logarithm problems, or the quadratic residues, which are shown by Lee et al. that none of the schemes is able to meet the two fundamental properties above. Therefore, an ECC-based blind signature scheme that possesses both the above properties is proposed in this paper.

  17. Loading Schemes for Downlink OFDMA Systems

    Institute of Scientific and Technical Information of China (English)

    KONG Jian; LIU Fang; WANG Wen-bo; LIU Yuan-an

    2004-01-01

    In this paper we study the subcarrier and bit allocation strategies for downlink OFDMA system. Our optimization objective is to find optimum subcarrier and bit assignment minimizing the total transmitted power with the constraints on BER and data rate for all users. We divide this problem into three steps: resource allocation, subcarrier assignment and single-user power and bit allocation. For the first two steps we propose new algorithms. Various loading schemes constitute by combining these algorithms as well as algorithms proposed in Ref . [ 6 ]. Simulation results demonstrate that our proposed suboptimal loading scheme can achieve performance closer to the near optimal algorithm in Ref . [ 8 ] with much lower complexity than schemes in Ref .[6].

  18. Threshold Ring Signature Scheme Based on TPM

    Institute of Scientific and Technical Information of China (English)

    Gong Bei; Jiang Wei; Lin Li; Li Yu; Zhang Xing

    2012-01-01

    The conventional ring signature schemes cannot address the scenario where the rank of members of the ring needs to be distinguished, for example, in electronically commerce application. To solve this problem, we presented a Trusted Platform Module (TPM)-based threshold ring signature schen. Employing a reliable secret Share Distribution Center (SDC), the proposed approach can authenticate the TPM-based identity rank of members of the ring but not track a specific member's identity. A subset including t members with the same identity rank is built. With the signing cooperation of t members of the subset, the ring signature based on Chinese remainder theorem is generated. We proved the anonymity and unforgeability of the proposed scheme and compared it with the threshold ring signature based on Lagrange interpolation polynomial. Our scheme is relatively simpler to calculate.

  19. Multi-Seed Key Distribution Scheme Test

    Institute of Scientific and Technical Information of China (English)

    XIE Yumin; SHI Feng; MING Yang; Muhammad Kamran; YANG Xiaoxu

    2006-01-01

    The key problem of securing multicast is to generate, distribute and update Session Encryption Key(SEK). Polynomial expansion with multi-seed(MPE) scheme is an approach which is based on Polynomial expansion(PE) scheme and overcomes PE's shortage. Its operation is demonstrated by using multi-seed, the group member is partitioned to many subgroups. While updating the SEK, computation is needed only in one of subgroups, the other of them will use the computation history to update their SEK. The key problems to design a MPE scheme application includes to find a feasible one way function as well as to generate a Strict Prime Number(SPN). Those technologies with multi-seed and computation history concepts make MPE as a good choice in practical applications. A prototype test system is designed and solutions of all above mentioned problems are included in this proposed paper.

  20. Scheme for multistep resonance photoionization of atoms

    Science.gov (United States)

    Liu, Bo; Ning, Xi-Jing

    2001-07-01

    Traditional schemes for multistep resonance photoionization of atoms let every employed laser beam interact with the atoms simultaneously. In such a situation, analyses via time-dependent Schrödinger equation show that high ionization probability requires all the laser beams must be intense enough. In order to decrease laser intensity, we proposed a scheme that the laser beam used to pump the excited atoms (in a higher bound state) into an autoionization state does not interact with the atoms until all the population is transferred by the other lasers from a ground state to the bound state. As an interesting example, we examined three-step photoionization of 235U with our scheme, showing that the intensity of two laser beams can be lowered by two orders of magnitude without losing high ionization probability.

  1. Power Control Scheme of D-Statcom

    Directory of Open Access Journals (Sweden)

    A. Sai Krishna,

    2014-06-01

    Full Text Available This paper presents an instantaneous power control scheme of D-STATCOM for power factor and harmonic compensation. The control strategy has been introduced in order to enhance some steady-state performances and elimination of power quality disturbances. Power factor and harmonic current of a controlled feeder section are two vital roles in steady-state power distribution system operation. In this paper, a control scheme with constant power and sinusoidal current compensation is exploited. And the proposed control scheme is designed to correct the power factor. In order to correct the power factor, a power factor control loop is required and therefore included in the control block. The DC voltage across the DC link capacitor must be large enough and kept constant at that value to stabilize the compensation. Therefore, DC link voltage regulator must be added to the control loop. Simulation is performed in two cases.

  2. IPCT: A scheme for mobile authentication

    Directory of Open Access Journals (Sweden)

    Vishnu Shankar

    2016-09-01

    Full Text Available Mobile is becoming a part of everyone's life and as their power of computation and storage is rising and cost is coming down. Most of mobile phone users have a lot of private data which they want to protect from others (La Polla et al., 2013. It means user must be authenticated properly for accessing the mobile resources. Normally user is authenticated using text passwords, PIN, face recognition or patterns etc. All these methods are used but they have some shortcomings. In this paper we have seen various existing methods of mobile authentications and proposed our improved mobile authentication IPCT scheme. We have compared our Image Pass Code with tapping scheme with existing techniques and shown that our scheme is better than existing techniques.

  3. Optimal Sales Schemes for Network Goods

    DEFF Research Database (Denmark)

    Parakhonyak, Alexei; Vikander, Nick

    This paper examines the optimal sequencing of sales in the presence of network externalities. A firm sells a good to a group of consumers whose payoff from buying is increasing in total quantity sold. The firm selects the order to serve consumers so as to maximize expected sales. It can serve all...... consumers simultaneously, serve them all sequentially, or employ any intermediate scheme. We show that the optimal sales scheme is purely sequential, where each consumer observes all previous sales before choosing whether to buy himself. A sequential scheme maximizes the amount of information available...... to consumers, allowing success to breed success. Failure can also breed failure, but this is made less likely by consumers’ desire to influence one another’s behavior. We show that when consumers differ in the weight they place on the network externality, the firm would like to serve consumers with lower...

  4. A numerical scheme for multifluid magnetohydrodynamics

    CERN Document Server

    Falle, S A

    2003-01-01

    This paper describes a numerical scheme for multi-fluid hydrodynamics in the limit of small mass densities of the charged particles. The inertia of the charged particles can then be neglected, which makes it possible to write an evolution equation for the magnetic field that can be solved using an implicit scheme. This avoids the severe restriction on the stable timestep that would otherwise arise at high resolution, or when the Hall effect is large. Numerical tests show that the scheme can accurately model steady multi-fluid shock structures both with and without sub-shocks. Although the emphasis is on shocks in molecular clouds, a multi-dimensional version of this code could be applied to any Astrophysical flow in which ambi-polar diffusion or the Hall effect, or both play a significant role.

  5. Tradable white certificate schemes : what can we learn from tradable green certificate schemes?

    NARCIS (Netherlands)

    Oikonomou, Vlasis; Mundaca, Luis

    2008-01-01

    In this paper, we analyze the experiences gained from tradable green certificate (TGC) schemes and extract some policy lessons that can lead to a successful design of a market-based approach for energy efficiency improvement, alias tradable white certificate schemes. We use tradable green certificat

  6. Autonomous droop scheme with reduced generation cost

    DEFF Research Database (Denmark)

    Nutkani, Inam Ullah; Loh, Poh Chiang; Blaabjerg, Frede

    2013-01-01

    Droop scheme has been widely applied to the control of Distributed Generators (DGs) in microgrids for proportional power sharing based on their ratings. For standalone microgrid, where centralized management system is not viable, the proportional power sharing based droop might not suit well since...... DGs are usually of different types unlike synchronous generators. This paper presents an autonomous droop scheme that takes into consideration the operating cost, efficiency and emission penalty of each DG since all these factors directly or indirectly contributes to the Total Generation Cost (TGC...

  7. On the Dynamics of TVD Schemes

    Science.gov (United States)

    Yee, H. C.; Sweby, P. K.; Kutler, Paul (Technical Monitor)

    1994-01-01

    The dynamics of a class of TVD schemes for model hyperbolic and parabolic equations is studied numerically using a highly parallel supercomputer (CM-5). The objective is to utilize the highly parallel property of the CM-5 to reveal the reliable time step and entropy parameter ranges, and the degree of compressible flux limiters to avoid slow convergence and the production of nonphysical numerical solutions. We choose to study the nonlinear stability property of TVD schemes numerically since it is otherwise not amenable analytically.

  8. Security problem on arbitrated quantum signature schemes

    Science.gov (United States)

    Choi, Jeong Woon; Chang, Ku-Young; Hong, Dowon

    2011-12-01

    Many arbitrated quantum signature schemes implemented with the help of a trusted third party have been developed up to now. In order to guarantee unconditional security, most of them take advantage of the optimal quantum one-time encryption based on Pauli operators. However, in this paper we point out that the previous schemes provide security only against a total break attack and show in fact that there exists an existential forgery attack that can validly modify the transmitted pair of message and signature. In addition, we also provide a simple method to recover security against the proposed attack.

  9. How the Pharmaceutical Benefits Scheme began.

    Science.gov (United States)

    Goddard, Martyn S

    2014-07-01

    Seventy years ago, the Curtin wartime government introduced legislation for a Pharmaceutical Benefits Scheme (PBS). It was a response to the need to provide access to a wave of antibiotic drugs - sulfonamides, streptomycin, penicillin - to the whole population, not only to the minority able to afford them. The scheme was immediately and successfully opposed by doctors and the conservative opposition, which saw in universal health care an underhand plan to nationalise medicine. There were two High Court challenges, two referendums and a constitutional amendment; but it was not until 1960 that Australians had the comprehensive PBS envisaged by Curtin in 1944. PMID:25047771

  10. Cheater identifiable visual secret sharing scheme

    Institute of Scientific and Technical Information of China (English)

    Gan Zhi; Chen Kefei

    2005-01-01

    The visual secret sharing scheme proposed by Naor and Shamir provides a way to encrypt a secret black-white image into shares. A qualified group of participants can recover the secret message without using any cryptographic computation. But the original scheme can easily be corrupted by malicious participant. We propose an extension of VSS(visual secret sharing) to identify cheaters before the secret is recovered. Without the need for any additional information and cryptographic computation, every participant can verify the validity of shares of other participants, thus the security of VSS is enhanced.

  11. Security problem on arbitrated quantum signature schemes

    CERN Document Server

    Choi, Jeong Woon; Hong, Dowon

    2011-01-01

    Until now, there have been developed many arbitrated quantum signature schemes implemented with a help of a trusted third party. In order to guarantee the unconditional security, most of them take advantage of the optimal quantum one-time encryption method based on Pauli operators. However, we in this paper point out that the previous schemes only provides a security against total break and actually show that there exists a simple existential forgery attack to validly modify the transmitted pair of message and signature. In addition, we also provide a simple method to recover the security against the proposed attack.

  12. UPWIND FINITE VOLUME SCHEMES FOR SEMICONDUCTOR DEVICE

    Institute of Scientific and Technical Information of China (English)

    杨青

    2003-01-01

    The mathematical model of semiconductor devices is described by the initial boundary value problem of a system of three nonlinear partial differential equations.One equation in elliptic form is for the electrostatic potential;two equations of convection-dominated diffusion type are for the electron and hole concentrations.Finite volume element procedure are put forward for the electrostatic potential,while upwind volume element schemes for the two concentration equations.Error estimates in L2norm for our numerical schemes are derived.

  13. ARQ scheme reinforced with past acknowledgement signals

    Science.gov (United States)

    Nakamura, Makoto; Takada, Yasushi

    An ARQ (automatic-repeat-request) scheme that can reduce the influence of backward channel errors for bidirectional data transmission systems is proposed. The main feature of the scheme is that both present and past acknowledgement signals are utilized to decide whether the data signals should be retransmitted or not. Throughput performance is analyzed in both go-back-N and selective-repeat ARQ. A small number of returned past acknowledgement signals are required to improve the throughput efficiency. For an ideal selective-repeat ARQ with an infinite buffer, increasing the number of returned past acknowledgement signals makes the throughput efficiency asymptotically close to the upper bound.

  14. Clocking Scheme for Switched-Capacitor Circuits

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper

    1998-01-01

    A novel clocking scheme for switched-capacitor (SC) circuits is presented. It can enhance the understanding of SC circuits and the errors caused by MOSFET (MOS) switches. Charge errors, and techniques to make SC circuits less sensitive to them are discussed.......A novel clocking scheme for switched-capacitor (SC) circuits is presented. It can enhance the understanding of SC circuits and the errors caused by MOSFET (MOS) switches. Charge errors, and techniques to make SC circuits less sensitive to them are discussed....

  15. Accelerated Simulation Scheme for Solving Financial Problems

    Directory of Open Access Journals (Sweden)

    Farshid Mehrdoust

    2014-03-01

    Full Text Available The Monte Carlo simulation method uses random sampling to study properties of systems with components that behave in a random state. More precisely, the idea is to simulate on the computer the behavior of these systems by randomly generating the variables describing the behavior of their components. In this paper, we propose an efficient and reliable simulation scheme based on Monte Carlo algorithm and combining two variance reduction procedures. We simulate a European option price numerically using the proposed simulation scheme.

  16. A compression tolerant scheme for image authentication

    Institute of Scientific and Technical Information of China (English)

    刘宝锋; 张文军; 余松煜

    2004-01-01

    Image authentication techniques used to protect the recipients against malicious forgery. In this paper, we propose a new image authentication technique based on digital signature. The authentication is verified by comparing the features of the each block in tested image with the corresponding features of the block recorded in the digital signature. The proposed authentication scheme is capable of distinguishing visible but non-malicious changes due to common processing operations from malicious changes. At last our experimental results show that the proposed scheme is not only efficient to protect integrity of image, but also with low computation,which are feasible for practical applications.

  17. A Survey of Unix Init Schemes

    CERN Document Server

    Royon, Yvan

    2007-01-01

    In most modern operating systems, init (as in "initialization") is the program launched by the kernel at boot time. It runs as a daemon and typically has PID 1. Init is responsible for spawning all other processes and scavenging zombies. It is also responsible for reboot and shutdown operations. This document describes existing solutions that implement the init process and/or init scripts in Unix-like systems. These solutions range from the legacy and still-in-use BSD and SystemV schemes, to recent and promising schemes from Ubuntu, Apple, Sun and independent developers. Our goal is to highlight their focus and compare their sets of features.

  18. LEARNING WITH ERROR BASED SEARCHABLE ENCRYPTION SCHEME

    Institute of Scientific and Technical Information of China (English)

    Zhang Jiuling; Deng Beixing; Li Xing

    2012-01-01

    A learning with error problem based encryption scheme that allows secure searching over the cipher text is proposed.Both the generation of cipher text and the trapdoor of the query are based on the problem of learning with errors.By performing an operation over the trapdoor and the cipher text,it is able to tell if the cipher text is the encryption of a plaintext.The secure searchable encryption scheme is both cipher text and trapdoor indistinguishable.The probabilities of missing and failing match occurrence in searching are both exponentially small.

  19. Verification of an objective analysis scheme

    International Nuclear Information System (INIS)

    An intermittent data assimilation scheme has been used to produce wind and precipitation fields during the 10 days after the explosion at the Chernobyl nuclear power plant on 25 April 1986. The wind fields are analyses, the precipitation fields have been generated by the forecast model part of the scheme. The precipitation fields are of fair quality. The quality of the wind fields has been monitored by the ensuing trajectories. These were found to describe the arrival times of radioactive air in good agreement with most observational data, taken all over Europe. The wind analyses are therefore considered to be reliable. 25 refs.; 13 figs

  20. A Modified Model Predictive Control Scheme

    Institute of Scientific and Technical Information of China (English)

    Xiao-Bing Hu; Wen-Hua Chen

    2005-01-01

    In implementations of MPC (Model Predictive Control) schemes, two issues need to be addressed. One is how to enlarge the stability region as much as possible. The other is how to guarantee stability when a computational time limitation exists. In this paper, a modified MPC scheme for constrained linear systems is described. An offline LMI-based iteration process is introduced to expand the stability region. At the same time, a database of feasible control sequences is generated offline so that stability can still be guaranteed in the case of computational time limitations. Simulation results illustrate the effectiveness of this new approach.

  1. Engineering images designed by fractal subdivision scheme.

    Science.gov (United States)

    Mustafa, Ghulam; Bari, Mehwish; Jamil, Saba

    2016-01-01

    This paper is concerned with the modeling of engineering images by the fractal properties of 6-point binary interpolating scheme. Association between the fractal behavior of the limit curve/surface and the parameter is obtained. The relationship between the subdivision parameter and the fractal dimension of the limit fractal curve of subdivision fractal is also presented. Numerical examples and visual demonstrations show that 6-point scheme is good choice for the generation of fractals for the modeling of fractal antennas, bearings, garari's and rock etc. PMID:27652066

  2. Comparison of actinides and fission products recycling scheme with the normal plutonium recycling scheme in fast reactors

    Directory of Open Access Journals (Sweden)

    Salahuddin Asif

    2013-01-01

    Full Text Available Multiple recycling of actinides and non-volatile fission products in fast reactors through the dry re-fabrication/reprocessing atomics international reduction oxidation process has been studied as a possible way to reduce the long-term potential hazard of nuclear waste compared to that resulting from reprocessing in a wet PUREX process. Calculations have been made to compare the actinides and fission products recycling scheme with the normal plutonium recycling scheme in a fast reactor. For this purpose, the Karlsruhe version of isotope generation and depletion code, KORIGEN, has been modified accordingly. An entirely novel fission product yields library for fast reactors has been created which has replaced the old KORIGEN fission products library. For the purposes of this study, the standard 26 groups data set, KFKINR, developed at Forschungszentrum Karlsruhe, Germany, has been extended by the addition of the cross-sections of 13 important actinides and 68 most important fission products. It has been confirmed that these 68 fission products constitute about 95% of the total fission products yield and about 99.5% of the total absorption due to fission products in fast reactors. The amount of fissile material required to guarantee the criticality of the reactor during recycling schemes has also been investigated. Cumulative high active waste per ton of initial heavy metal is also calculated. Results show that the recycling of actinides and fission products in fast reactors through the atomics international reduction oxidation process results in a reduction of the potential hazard of radioactive waste.

  3. A Hash Based Remote User Authentication and Authenticated Key Agreement Scheme for the Integrated EPR Information System.

    Science.gov (United States)

    Li, Chun-Ta; Weng, Chi-Yao; Lee, Cheng-Chi; Wang, Chun-Cheng

    2015-11-01

    To protect patient privacy and ensure authorized access to remote medical services, many remote user authentication schemes for the integrated electronic patient record (EPR) information system have been proposed in the literature. In a recent paper, Das proposed a hash based remote user authentication scheme using passwords and smart cards for the integrated EPR information system, and claimed that the proposed scheme could resist various passive and active attacks. However, in this paper, we found that Das's authentication scheme is still vulnerable to modification and user duplication attacks. Thereafter we propose a secure and efficient authentication scheme for the integrated EPR information system based on lightweight hash function and bitwise exclusive-or (XOR) operations. The security proof and performance analysis show our new scheme is well-suited to adoption in remote medical healthcare services.

  4. Energy Efficient MAC Scheme for Wireless Sensor Networks with High-Dimensional Data Aggregate

    Directory of Open Access Journals (Sweden)

    Seokhoon Kim

    2015-01-01

    Full Text Available This paper presents a novel and sustainable medium access control (MAC scheme for wireless sensor network (WSN systems that process high-dimensional aggregated data. Based on a preamble signal and buffer threshold analysis, it maximizes the energy efficiency of the wireless sensor devices which have limited energy resources. The proposed group management MAC (GM-MAC approach not only sets the buffer threshold value of a sensor device to be reciprocal to the preamble signal but also sets a transmittable group value to each sensor device by using the preamble signal of the sink node. The primary difference between the previous and the proposed approach is that existing state-of-the-art schemes use duty cycle and sleep mode to save energy consumption of individual sensor devices, whereas the proposed scheme employs the group management MAC scheme for sensor devices to maximize the overall energy efficiency of the whole WSN systems by minimizing the energy consumption of sensor devices located near the sink node. Performance evaluations show that the proposed scheme outperforms the previous schemes in terms of active time of sensor devices, transmission delay, control overhead, and energy consumption. Therefore, the proposed scheme is suitable for sensor devices in a variety of wireless sensor networking environments with high-dimensional data aggregate.

  5. Central difference TVD and TVB schemes for time dependent and steady state problems

    Science.gov (United States)

    Jorgenson, P.; Turkel, E.

    1992-01-01

    We use central differences to solve the time dependent Euler equations. The schemes are all advanced using a Runge-Kutta formula in time. Near shocks, a second difference is added as an artificial viscosity. This reduces the scheme to a first order upwind scheme at shocks. The switch that is used guarantees that the scheme is locally total variation diminishing (TVD). For steady state problems it is usually advantageous to relax this condition. Then small oscillations do not activate the switches and the convergence to a steady state is improved. To sharpen the shocks, different coefficients are needed for different equations and so a matrix valued dissipation is introduced and compared with the scalar viscosity. The connection between this artificial viscosity and flux limiters is shown. Any flux limiter can be used as the basis of a shock detector for an artificial viscosity. We compare the use of the van Leer, van Albada, mimmod, superbee, and the 'average' flux limiters for this central difference scheme. For time dependent problems, we need to use a small enough time step so that the CFL was less than one even though the scheme was linearly stable for larger time steps. Using a total variation bounded (TVB) Runge-Kutta scheme yields minor improvements in the accuracy.

  6. Central difference TVD schemes for time dependent and steady state problems

    Energy Technology Data Exchange (ETDEWEB)

    Jorgenson, P. (NASA Lewis Research Center, Cleveland, OH (United States)); Turkel, E. (Tel-Aviv Univ. (Israel))

    1993-08-01

    We use central difference to solve the time dependent Euler equations. The schemes are all advanced using a Runge-Kutta formula in time. Near shocks a second difference is added as an artificial viscosity. this reduces the scheme to a first-order upwind scheme at shocks. the switch that is used guarantees that the scheme is TVD. For steady state problems it is usually advantageous to relax this condition. Then small oscillations do not activate the switches and the convergence to a steady state is improved. To sharpen the shocks different coefficients are needed for different equations, so a matrix-valued dissipation is introduced and compared with the scalar viscosity. The connection between this artificial viscosity and flux limiters is shown. Any flux limiter can be used as the basis of shock detector for an artificial viscosity. We compare the use of the van Leer, van Albada, minmod, superbee, and the [open quotes]average[close quotes]flux limiters for this central difference scheme. For time dependent problems were need to use a small enough time step so that the CFL is less than one even though the scheme is linearly stable for larger time steps. Using a TVB Runge-Kutta scheme yields minor improvements in the accuracy. 14 refs., 10 figs.

  7. Ternary 4-Point Interpolating Scheme for Curve Sketching

    Directory of Open Access Journals (Sweden)

    Shahid S. Siddiqi

    2013-07-01

    Full Text Available Subdivision schemes as an alternative approach in computer graphics are very much appreciated, a new ternary 4-point interpolating subdivision scheme has been proposed that generates the smooth limiting curves of C2 continuity using a global control tension parameter. A comparison of the proposed subdivision scheme along with examples has been demonstrated with the existing schemes. Comparison established that the proposed subdivision scheme behaves better than the existing schemes for a wider range of tension parameter. The limiting curve of the scheme has been observed to be close to the control polygon.

  8. On a New Difference Scheme-ATVD2

    OpenAIRE

    Ogawa, Satoru; Wada, Yasuhiro; ISHIGURO, Tomiko; Takakura, Yoko; 小川, 哲; 和田, 安弘; 石黒, 登美子; 高倉, 葉子

    1988-01-01

    A new difference scheme ATVD2 is proposed, which is constructed by applying the modified flux method proposed by Harten for TVD2 (UNO2) scheme. The numerical experiment of ONERA-M6 wing test case shows the solutions of proposed scheme without artificial compression parameter almost coincide with those of Harten-Yee TVD scheme and Chakravarthy-Osher TVD scheme with maximum value of artificial compression parameter. This fact shows the proposed scheme is more accurate than other TVD schemes in ...

  9. Scheme of adaptive polarization filtering based on Kalman model

    Institute of Scientific and Technical Information of China (English)

    Song Lizhong; Qi Haiming; Qiao Xiaolin; Meng Xiande

    2006-01-01

    A new kind of adaptive polarization filtering algorithm in order to suppress the angle cheating interference for the active guidance radar is presented. The polarization characteristic of the interference is dynamically tracked by using Kalman estimator under variable environments with time. The polarization filter parameters are designed according to the polarization characteristic of the interference, and the polarization filtering is finished in the target cell. The system scheme of adaptive polarization filter is studied and the tracking performance of polarization filter and improvement of angle measurement precision are simulated. The research results demonstrate this technology can effectively suppress the angle cheating interference in guidance radar and is feasible in engineering.

  10. On the Equivalence of Regularization Schemes

    Institute of Scientific and Technical Information of China (English)

    YANG Ji-Feng

    2002-01-01

    We illustrate via the sunset diagram that dimensional regularization ‘deforms' the nonlocal contentsof multi-loop diagrams with its equivalence to cutoff regularization scheme recovered only after sub-divergence wassubtracted. Then we employed a differential equation approach for calculating loop diagrams to verify that dimensionalare argued especially in nonperturbativc perspective.

  11. The EU Greenhouse Gas Emissions Trading Scheme

    NARCIS (Netherlands)

    Woerdman, Edwin; Woerdman, Edwin; Roggenkamp, Martha; Holwerda, Marijn

    2015-01-01

    This chapter explains how greenhouse gas emissions trading works, provides the essentials of the Directive on the European Union Emissions Trading Scheme (EU ETS) and summarizes the main implementation problems of the EU ETS. In addition, a law and economics approach is used to discuss the dilemmas

  12. Implicit and semi-implicit schemes: algorithms

    NARCIS (Netherlands)

    Keppens, R.; Toth, G.; Botchev, M.A.; Ploeg, van der A.

    1999-01-01

    This study formulates general guidelines to extend an explicit code with a great variety of implicit and semi-implicit time integration schemes. The discussion is based on their specific implementation in the Versatile Advection Code, which is a general purpose software package for solving systems o

  13. Implicit and semi-implicit schemes: Algorithms

    NARCIS (Netherlands)

    Keppens, R.; Toth, G.; Botchev, M. A.; van der Ploeg, A.

    1999-01-01

    This study formulates general guidelines to extend an explicit code with a great variety of implicit and semi-implicit time integration schemes. The discussion is based on their specific implementation in the Versatile Advection Code, which is a general purpose software package for solving systems o

  14. A Recursive Threshold Visual Cryptography Scheme

    CERN Document Server

    Parakh, Abhishek

    2009-01-01

    This paper presents a recursive hiding scheme for 2 out of 3 secret sharing. In recursive hiding of secrets, the user encodes additional information about smaller secrets in the shares of a larger secret without an expansion in the size of the latter, thereby increasing the efficiency of secret sharing. We present applications of our proposed protocol to images as well as text.

  15. High Order Semi-Lagrangian Advection Scheme

    Science.gov (United States)

    Malaga, Carlos; Mandujano, Francisco; Becerra, Julian

    2014-11-01

    In most fluid phenomena, advection plays an important roll. A numerical scheme capable of making quantitative predictions and simulations must compute correctly the advection terms appearing in the equations governing fluid flow. Here we present a high order forward semi-Lagrangian numerical scheme specifically tailored to compute material derivatives. The scheme relies on the geometrical interpretation of material derivatives to compute the time evolution of fields on grids that deform with the material fluid domain, an interpolating procedure of arbitrary order that preserves the moments of the interpolated distributions, and a nonlinear mapping strategy to perform interpolations between undeformed and deformed grids. Additionally, a discontinuity criterion was implemented to deal with discontinuous fields and shocks. Tests of pure advection, shock formation and nonlinear phenomena are presented to show performance and convergence of the scheme. The high computational cost is considerably reduced when implemented on massively parallel architectures found in graphic cards. The authors acknowledge funding from Fondo Sectorial CONACYT-SENER Grant Number 42536 (DGAJ-SPI-34-170412-217).

  16. Optimal design of funded pension schemes

    NARCIS (Netherlands)

    Bovenberg, A.L.; Mehlkopf, R.J.

    2014-01-01

    This article reviews the literature on the optimal design and regulation of funded pension schemes. We first characterize optimal saving and investment over an individual’s life cycle. Within a stylized modeling framework, we explore optimal individual saving and investing behavior. Subsequently, va

  17. Harmonic generation with multiple wiggler schemes

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, R.; De Salvo, L.; Pierini, P. [Universita degli Studi, Milano (Italy)

    1995-02-01

    In this paper the authors give a simple theoretical description of the basic physics of the single pass high gain free electron laser (FEL), describing in some detail the FEL bunching properties and the harmonic generation technique with a multiple-wiggler scheme or a high gain optical klystron configuration.

  18. Pipe blowdown analysis using explicit numerical schemes

    International Nuclear Information System (INIS)

    Several explicit numerical schemes were investigated to solve the homogeneous equations of change for one-dimensional fluid flow and heat transfer. The most successful technique investigated is the alternating gradient method which is based on the two-step Lax-Wendroff procedure. Agreement with experimental results is very good. (U.S.)

  19. Performance Evaluation of Modified Signcryption Scheme

    Directory of Open Access Journals (Sweden)

    Bharat Gupta

    2012-12-01

    Full Text Available Before a message is sent out, the sender of the message would sign it using a digital signature scheme and then encrypt the message (and the signature use a private key encryption algorithm under a randomly chosen message encryption key. The random message encryption key would then be encrypted using the recipient's public key. We call this process two-step approach: “signature-then-encryption”. Concept signcryption, first proposed by Zheng, is a cryptography primitive which combines both the functions of digital signature and public key encryption in a logical single step, and with a computational cost and communication overhead are significantly lower than that needed by traditional signature then encryption. In Zheng’s scheme, the signature verification can be done recipient’s private key at receiverend and its security are based on mainly Discrete Logarithm Problem (DLP, reversing one way hash function. In proposed modified signcryption scheme, security is based on the intractability of three hard problems: Discrete Logarithm Problem, reversing one way hash function and to determine prime factors of a composit number. Proposed signcryption scheme has all the benefits of signcryption and is also able to resolve the dispute / problem of non repudiation by independent third party, without compromising with sender and recipient’s private keys.

  20. Security of Invertible Media Authentication Schemes Revisited

    Science.gov (United States)

    Dönigus, Daniel; Endler, Stefan; Fischlin, Marc; Hülsing, Andreas; Jäger, Patrick; Lehmann, Anja; Podrazhansky, Sergey; Schipp, Sebastian; Tews, Erik; Vowe, Sven; Walthart, Matthias; Weidemann, Frederik

    Dittmann, Katzenbeisser, Schallhart and Veith (SEC 2005) introduced the notion of invertible media authentication schemes, embedding authentication data in media objects via invertible watermarks. These invertible watermarks allow to recover the original media object (given a secret encryption key), as required for example in some medical applications where the distortion must be removable.

  1. AI & Law, logic and argument schemes

    NARCIS (Netherlands)

    Prakken, Henry

    2006-01-01

    This paper reviews the history of AI & Law research from the perspective of argument schemes. It starts with the observation that logic, although very well applicable to legal reasoning when there is uncertainty, vagueness and disagreement, is too abstract to give a fully satisfactory classification

  2. GVD compensation schemes with considering PMD

    Institute of Scientific and Technical Information of China (English)

    Aiying Yang(杨爱英); Anshi Xu(徐安士); Deming Wu(吴德明)

    2003-01-01

    Three group velocity dispersion (GVD) compensation schemes, i.e., the post-compensation, pre-compensation and hybrid-compensation schemes, are discussed with considering polarization mode disper-sion (PMD). In the 10- and 40-Gbit/s non-return-zero (NRZ) on-off-key (OOK) systems, three physicalfactors, Kerr effect, GVD and PMD are considered. The numerical results show that, when the impactof PMD is taken into account, the GVD pre-compensation scheme performs best with more than 1 dBbetter of average eye-opening penalty (EOP) when input power is up to 10 dBm in the 10-Gbit/s system.However the GVD post-compensation scheme perforns best for the case of 40 Gbit/s with input power lessthan 13 dBm, and GVD pre-compensation will be better if the input power increased beyond this range.The results are different from those already reported under the assumption that the impact of PMD isneglected. Therefore, the research in this paper provide a different insight into the system optimizationwhen PMD, Kerr effect and GVD are considered.

  3. Creating Culturally Sustainable Agri-Environmental Schemes

    Science.gov (United States)

    Burton, Rob J. F.; Paragahawewa, Upananda Herath

    2011-01-01

    Evidence is emerging from across Europe that contemporary agri-environmental schemes are having only limited, if any, influence on farmers' long-term attitudes towards the environment. In this theoretical paper we argue that these approaches are not "culturally sustainable," i.e. the actions are not becoming embedded within farming cultures as…

  4. The European Emissions Trading Scheme case law

    NARCIS (Netherlands)

    J.A.W. van Zeben

    2009-01-01

    Within European climate change and energy policy, the European Emissions Trading Scheme (EU ETS) occupies a prominent role. This article considers the developing case law of the European courts on the EU ETS. Specific attention is paid to the role of the different actors within the EU ETS and the im

  5. A Novel MBAFF Scheme of AVS

    Institute of Scientific and Technical Information of China (English)

    Jian-Wen Chen; Guo-Ping Li; Yun He

    2006-01-01

    Adaptive frame/field coding techniques have been adopted in many international video standards for interlaced sequence coding. When the frame/field adaptation is applied on the picture level, the coding efficiency is improved greatly,compared with the pure frame coding or the pure field coding. The picture-level adaptive frame/field coding (PAFF) selects frame coding or field coding once for one picture. If this frame/field adaptation is extended to Macro Block (MB) level, the coding efficiency will be further increased. In this paper, a novel MB-level adaptive frame/field (MBAFF) coding scheme is proposed. In the proposed MBAFF scheme, the top field of the current picture is used as a reference. The experiments are implemented on the platforms of Audio Video coding Standard (AVS) base profile and H.264/AVC, respectively. On the AVS platform, 0.35dB gain can be achieved averagely, compared with AVS1.0 anchor. On the H.264/AVC platform, 0.16dB gain can be achieved averagely, compared with MBAFF scheme of H.264/AVC. Additionally, an extensive subjective quality enhancement can be achieved by the proposed scheme.

  6. Value constraints in the CLP scheme

    NARCIS (Netherlands)

    Emden, M.H. van

    1996-01-01

    This paper addresses the question of how to incorporate constraint propagation into logic programming. A likely candidate is the CLP scheme, which allows one to exploit algorithmic opportunities while staying within logic programming semantics. CLP($cal R$) is an example: it combines logic programmi

  7. Multiresolution schemes for conservation laws with viscosity

    International Nuclear Information System (INIS)

    This paper presents multiresolution schemes for the efficient numerical solution of one-dimensional conservation laws with viscosity. The method, originally developed by A, Harten (Commun. Pure Appl. Math., to appear) for hyperbolic conservation laws, computes the cell average multiresolution representation of the solution which provides much information about the solution's regularity. As a consequence, the possibly expensive ENO (essentially nonoscillatory) reconstruction as well as numerous flux computations are performed only near discontinuities, and thereby the numerical solution procedure becomes considerably more efficient. The multiresolution scheme is also expected to open-quotes followclose quotes possibly unsteady irregularities from one time step to the next. When viscosity is added, predicting the location of the irregularity becomes a problem of estimating the change in shock thickness. To this end, we derive shock width estimates for our 1D prototype equations, which, when combined with the stability restriction of the numerical scheme, provide a reliable mechanism for enlarging the original multiresolution stencil. The numerical experiments for scalar conservation laws indicate the feasibility of multiresolution schemes for the viscous case as well

  8. Storage System Design Scheme in Virtualization Construction

    Institute of Scientific and Technical Information of China (English)

    Si Zhen-yu

    2012-01-01

    In order to improve resource utilization, it is necessary to integrate storage and data, and the emergence of cloud computing makes it possible. This paper analyzed the study of virtualization and cloud computing, proposed a new scheme based on virtualization, and established a shared storage platform, which made a good complement and perfected the centralized storage platform.

  9. Two modified discrete chirp Fourier transform schemes

    Institute of Scientific and Technical Information of China (English)

    樊平毅; 夏香根

    2001-01-01

    This paper presents two modified discrete chirp Fourier transform (MDCFT) schemes.Some matched filter properties such as the optimal selection of the transform length, and its relationship to analog chirp-Fourier transform are studied. Compared to the DCFT proposed previously, theoretical and simulation results have shown that the two MDCFTs can further improve the chirp rate resolution of the detected signals.

  10. Cross-ontological analytics for alignment of different classification schemes

    Science.gov (United States)

    Posse, Christian; Sanfilippo, Antonio P; Gopalan, Banu; Riensche, Roderick M; Baddeley, Robert L

    2010-09-28

    Quantification of the similarity between nodes in multiple electronic classification schemes is provided by automatically identifying relationships and similarities between nodes within and across the electronic classification schemes. Quantifying the similarity between a first node in a first electronic classification scheme and a second node in a second electronic classification scheme involves finding a third node in the first electronic classification scheme, wherein a first product value of an inter-scheme similarity value between the second and third nodes and an intra-scheme similarity value between the first and third nodes is a maximum. A fourth node in the second electronic classification scheme can be found, wherein a second product value of an inter-scheme similarity value between the first and fourth nodes and an intra-scheme similarity value between the second and fourth nodes is a maximum. The maximum between the first and second product values represents a measure of similarity between the first and second nodes.

  11. Probabilistic Performance Analysis of Fault Diagnosis Schemes

    Science.gov (United States)

    Wheeler, Timothy Josh

    The dissertation explores the problem of rigorously quantifying the performance of a fault diagnosis scheme in terms of probabilistic performance metrics. Typically, when the performance of a fault diagnosis scheme is of utmost importance, physical redundancy is used to create a highly reliable system that is easy to analyze. However, in this dissertation, we provide a general framework that applies to more complex analytically redundant or model-based fault diagnosis schemes. For each fault diagnosis problem in this framework, our performance metrics can be computed accurately in polynomial-time. First, we cast the fault diagnosis problem as a sequence of hypothesis tests. At each time, the performance of a fault diagnosis scheme is quantified by the probability that the scheme has chosen the correct hypothesis. The resulting performance metrics are joint probabilities. Using Bayes rule, we decompose these performance metrics into two parts: marginal probabilities that quantify the reliability of the system and conditional probabilities that quantify the performance of the fault diagnosis scheme. These conditional probabilities are used to draw connections between the fault diagnosis and the fields of medical diagnostic testing, signal detection, and general statistical decision theory. Second, we examine the problem of computing the performance metrics efficiently and accurately. To solve this problem, we examine each portion of the fault diagnosis problem and specify a set of sufficient assumptions that guarantee efficient computation. In particular, we provide a detailed characterization of the class of finite-state Markov chains that lead to tractable fault parameter models. To demonstrate that these assumptions enable efficient computation, we provide pseudocode algorithms and prove that their running time is indeed polynomial. Third, we consider fault diagnosis problems involving uncertain systems. The inclusion of uncertainty enlarges the class of systems

  12. Arbitrated quantum signature scheme based on reusable key

    Science.gov (United States)

    Yu, ChaoHua; Guo, GongDe; Lin, Song

    2014-11-01

    An arbitrated quantum signature scheme without using entangled states is proposed. In the scheme, by employing a classical hash function and random numbers, the secret keys of signer and receiver can be reused. It is shown that the proposed scheme is secure against several well-known attacks. Specifically, it can stand against the receiver's disavowal attack. Moreover, compared with previous relevant arbitrated quantum signature schemes, the scheme proposed has the advantage of less transmission complexity.

  13. Arbitrated quantum signature scheme based on reusable key

    Institute of Scientific and Technical Information of China (English)

    YU ChaoHua; GUO GongDe; LIN Song

    2014-01-01

    An arbitrated quantum signature scheme without using entangled states is proposed.In the scheme,by employing a classical hash function and random numbers,the secret keys of signer and receiver can be reused.It is shown that the proposed scheme is secure against several well-known attacks.Specifically,it can stand against the receiver's disavowal attack.Moreover,compared with previous relevant arbitrated quantum signature schemes,the scheme proposed has the advantage of less transmission complexity.

  14. Finite difference schemes for long-time integration

    Science.gov (United States)

    Haras, Zigo; Taasan, Shlomo

    1993-01-01

    Finite difference schemes for the evaluation of first and second derivatives are presented. These second order compact schemes were designed for long-time integration of evolution equations by solving a quadratic constrained minimization problem. The quadratic cost function measures the global truncation error while taking into account the initial data. The resulting schemes are applicable for integration times fourfold, or more, longer than similar previously studied schemes. A similar approach was used to obtain improved integration schemes.

  15. Simple Numerical Schemes for the Korteweg-deVries Equation

    Energy Technology Data Exchange (ETDEWEB)

    C. J. McKinstrie; M. V. Kozlov

    2000-12-01

    Two numerical schemes, which simulate the propagation of dispersive non-linear waves, are described. The first is a split-step Fourier scheme for the Korteweg-de Vries (KdV) equation. The second is a finite-difference scheme for the modified KdV equation. The stability and accuracy of both schemes are discussed. These simple schemes can be used to study a wide variety of physical processes that involve dispersive nonlinear waves.

  16. Implicit and semi-implicit schemes: Algorithms

    Science.gov (United States)

    Keppens, R.; Tóth, G.; Botchev, M. A.; van der Ploeg, A.

    1999-06-01

    This study formulates general guidelines to extend an explicit code with a great variety of implicit and semi-implicit time integration schemes. The discussion is based on their specific implementation in the Versatile Advection Code, which is a general purpose software package for solving systems of non-linear hyperbolic (and/or parabolic) partial differential equations, using standard high resolution shock capturing schemes. For all combinations of explicit high resolution schemes with implicit and semi-implicit treatments, it is shown how second-order spatial and temporal accuracy for the smooth part of the solutions can be maintained. Strategies to obtain steady state and time accurate solutions implicitly are discussed. The implicit and semi-implicit schemes require the solution of large linear systems containing the Jacobian matrix. The Jacobian matrix itself is calculated numerically to ensure the generality of this implementation. Three options are discussed in terms of applicability, storage requirements and computational efficiency. One option is the easily implemented matrix-free approach, but the Jacobian matrix can also be calculated by using a general grid masking algorithm, or by an efficient implementation for a specific Lax-Friedrich-type total variation diminishing (TVD) spatial discretization. The choice of the linear solver depends on the dimensionality of the problem. In one dimension, a direct block tridiagonal solver can be applied, while in more than one spatial dimension, a conjugate gradient (CG)-type iterative solver is used. For advection-dominated problems, preconditioning is needed to accelerate the convergence of the iterative schemes. The modified block incomplete LU-preconditioner is implemented, which performs very well. Examples from two-dimensional hydrodynamic and magnetohydrodynamic computations are given. They model transonic stellar outflow and recover the complex magnetohydrodynamic bow shock flow in the switch-on regime

  17. Information field dynamics for simulation scheme construction

    Science.gov (United States)

    Enßlin, Torsten A.

    2013-01-01

    Information field dynamics (IFD) is introduced here as a framework to derive numerical schemes for the simulation of physical and other fields without assuming a particular subgrid structure as many schemes do. IFD constructs an ensemble of nonparametric subgrid field configurations from the combination of the data in computer memory, representing constraints on possible field configurations, and prior assumptions on the subgrid field statistics. Each of these field configurations can formally be evolved to a later moment since any differential operator of the dynamics can act on fields living in continuous space. However, these virtually evolved fields need again a representation by data in computer memory. The maximum entropy principle of information theory guides the construction of updated data sets via entropic matching, optimally representing these field configurations at the later time. The field dynamics thereby become represented by a finite set of evolution equations for the data that can be solved numerically. The subgrid dynamics is thereby treated within auxiliary analytic considerations. The resulting scheme acts solely on the data space. It should provide a more accurate description of the physical field dynamics than simulation schemes constructed ad hoc, due to the more rigorous accounting of subgrid physics and the space discretization process. Assimilation of measurement data into an IFD simulation is conceptually straightforward since measurement and simulation data can just be merged. The IFD approach is illustrated using the example of a coarsely discretized representation of a thermally excited classical Klein-Gordon field. This should pave the way towards the construction of schemes for more complex systems like turbulent hydrodynamics.

  18. Electricity storage using a thermal storage scheme

    Science.gov (United States)

    White, Alexander

    2015-01-01

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

  19. Comparative trials in registration files of cardiovascular drugs : Comparator drugs and dosing schemes.

    NARCIS (Netherlands)

    Wieringa, NF; Vos, R; de Graeff, PA

    2001-01-01

    Registration files of 13 cardiovascular drugs were analysed with respect to the number of double-blind phase-III clinical trials, the use of placebo and active comparator drugs and their dosing schemes. Half of the 146 double-blind trials used active comparator drugs. The majority of files included

  20. ECSM: Energy Efficient Clustering Scheme for Mobile M2M Communication Networks

    Directory of Open Access Journals (Sweden)

    Mohammed Saeed Al-kahtani

    2014-02-01

    Full Text Available Scheduling the active and idle period of machine ty pe communication devices (MTC such as RFID tags, sensors and smart meters are significant ly important to achieve energy efficiency in the emerging machine to machine (M2M communication networks, which comprises thousands of resource constrained MTC devices (i.e., low data rate, energy and bandwidth. However, only a few studies exist in the literature on node scheduling schemes of M2M communication networks. Most of these schemes consider only the e nergy efficiency of MTC devices and do not support mobility. Thus, we introduce an energy effi cient, node scheduling scheme for mobile M2M (ECSM communication networks. The ECSM schedul ing scheme selects a minimum number of active MTC devices in each cluster and in creases the probability of network coverage. Simulation results show that the ECSM sch eduling scheme outperforms the existing cluster-based and well-known mobility centric LEACH -M and LEACH-ME schemes in terms of network energy consumption and lifetime.

  1. Bidirectional Partial Generalized Synchronization in Chaotic and Hyperchaotic Systems via a New Scheme

    Institute of Scientific and Technical Information of China (English)

    WANG Qi

    2006-01-01

    In this paper, a bidirectional partial generalized (lag, complete, and anticipated) synchronization of a class of continuous-time systems is defined. Then based on the active control idea, a new systematic and concrete scheme is developed to achieve bidirectional partial generalized (lag, complete, and anticipated) synchronization between two chaotic systems or between chaotic and hyperchaotic systems. With the help of symbolic-numerical computation,we choose the modified Chua system, Lorenz system, and the hyperchaotic Tamasevicius-Namajunas-Cenys system to illustrate the proposed scheme. Numerical simulations are used to verify the effectiveness of the proposed scheme. It is interesting that partialchaos synchronization not only can take place between two chaotic systems, but also can take place between chaotic and hyperchaotic systems. The proposed scheme can also be extended to research bidirectional partial generalized (lag, complete, and anticipated) synchronization between other dynamical systems.

  2. Research on a New Control Scheme of Photovoltaic Grid Power Generation System

    Directory of Open Access Journals (Sweden)

    Dong-Hui Li

    2014-01-01

    Full Text Available A new type of photovoltaic grid power generation system control scheme to solve the problems of the conventional photovoltaic grid power generation systems is presented. To aim at the oscillation and misjudgment of traditional perturbation observation method, an improved perturbation observation method comparing to the next moment power is proposed, combining with BOOST step-up circuit to realize the maximum power tracking. To counter the harmonic pollution problem in photovoltaic grid power generation system, the deadbeat control scheme in fundamental wave synchronous frequency rotating coordinate system of power grid is presented. A parameter optimization scheme based on positive feedback of active frequency shift island detection to solve the problems like the nondetection zone due to the import of disturbance in traditional island detection method is proposed. Finally, the results in simulation environment by MATLAB/Simulink simulation and experiment environment verify the validity and superiority of the proposed scheme.

  3. A novel control scheme for simultaneous elimination of imbalance, disturbance and voltage harmonic in power systems

    Institute of Scientific and Technical Information of China (English)

    Javad Olamaei; Farnoosh NarjabadiFam; Amid Nazeri

    2014-01-01

    In recent years, the increasing application of nonlinear and unbalanced electronic equipment and large single phase loads have made voltage imbalance a serious problem in power distribution systems. A novel approach has been proposed to eliminate voltage imbalance and disturbances. The main strategy of this scheme is based on series active filter. By improving control circuit toward existing schemes and proposing a new strategy to control the voltage amplitude, simultaneous elimination of voltage imbalance, faults, voltage harmonics and also compensation of voltage drop in transmission lines become possible. Eventually, the voltage on the load side is a perfectly balanced three phase voltage with specific proper amplitude. The proposed scheme has been simulated in a test network and the results show high capability of this scheme for the complete elimination of imbalance without phase shift.

  4. A classification scheme for risk assessment methods.

    Energy Technology Data Exchange (ETDEWEB)

    Stamp, Jason Edwin; Campbell, Philip LaRoche

    2004-08-01

    This report presents a classification scheme for risk assessment methods. This scheme, like all classification schemes, provides meaning by imposing a structure that identifies relationships. Our scheme is based on two orthogonal aspects--level of detail, and approach. The resulting structure is shown in Table 1 and is explained in the body of the report. Each cell in the Table represent a different arrangement of strengths and weaknesses. Those arrangements shift gradually as one moves through the table, each cell optimal for a particular situation. The intention of this report is to enable informed use of the methods so that a method chosen is optimal for a situation given. This report imposes structure on the set of risk assessment methods in order to reveal their relationships and thus optimize their usage.We present a two-dimensional structure in the form of a matrix, using three abstraction levels for the rows and three approaches for the columns. For each of the nine cells in the matrix we identify the method type by name and example. The matrix helps the user understand: (1) what to expect from a given method, (2) how it relates to other methods, and (3) how best to use it. Each cell in the matrix represent a different arrangement of strengths and weaknesses. Those arrangements shift gradually as one moves through the table, each cell optimal for a particular situation. The intention of this report is to enable informed use of the methods so that a method chosen is optimal for a situation given. The matrix, with type names in the cells, is introduced in Table 2 on page 13 below. Unless otherwise stated we use the word 'method' in this report to refer to a 'risk assessment method', though often times we use the full phrase. The use of the terms 'risk assessment' and 'risk management' are close enough that we do not attempt to distinguish them in this report. The remainder of this report is organized as follows. In

  5. Schemes for applying active lubrication to main engine bearings

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    the dynamics of the injection for a piezo-actuated oil injector and a mechanical-actuated oil injector are presented in this study. It is shown how the dynamics of the oil injection system is coupled to the dynamics of the bearing fluid film through equations. The global system is numerically solved using...... as a case of study a single-cylinder combustion engine, where the conventional lubrication of the main bearing is modified by applying radial oil injection using piezo-actuated injection. The performance of such a hybrid bearing is compared to an equivalent conventional lubricated bearing in terms...

  6. Scheme for Quantum Computing Immune to Decoherence

    Science.gov (United States)

    Williams, Colin; Vatan, Farrokh

    2008-01-01

    A constructive scheme has been devised to enable mapping of any quantum computation into a spintronic circuit in which the computation is encoded in a basis that is, in principle, immune to quantum decoherence. The scheme is implemented by an algorithm that utilizes multiple physical spins to encode each logical bit in such a way that collective errors affecting all the physical spins do not disturb the logical bit. The scheme is expected to be of use to experimenters working on spintronic implementations of quantum logic. Spintronic computing devices use quantum-mechanical spins (typically, electron spins) to encode logical bits. Bits thus encoded (denoted qubits) are potentially susceptible to errors caused by noise and decoherence. The traditional model of quantum computation is based partly on the assumption that each qubit is implemented by use of a single two-state quantum system, such as an electron or other spin-1.2 particle. It can be surprisingly difficult to achieve certain gate operations . most notably, those of arbitrary 1-qubit gates . in spintronic hardware according to this model. However, ironically, certain 2-qubit interactions (in particular, spin-spin exchange interactions) can be achieved relatively easily in spintronic hardware. Therefore, it would be fortunate if it were possible to implement any 1-qubit gate by use of a spin-spin exchange interaction. While such a direct representation is not possible, it is possible to achieve an arbitrary 1-qubit gate indirectly by means of a sequence of four spin-spin exchange interactions, which could be implemented by use of four exchange gates. Accordingly, the present scheme provides for mapping any 1-qubit gate in the logical basis into an equivalent sequence of at most four spin-spin exchange interactions in the physical (encoded) basis. The complexity of the mathematical derivation of the scheme from basic quantum principles precludes a description within this article; it must suffice to report

  7. On the Behavior of Upwind Schemes in the Low Mach Number Limit: II. Godunov Type Schemes

    OpenAIRE

    Guillard, Hervé; Murrone, Angelo

    2001-01-01

    This paper presents an analysis of Godunov scheme in the low Mach number regime. We study the Riemann problem and show that the interface pressure contains acoustic waves of order Mach even if the initial data are well prepared and contain only pressure fluctuations of order Mach squared. We then propose to modify the fluxes computed by Godunov type schemes by solving a preconditioned Riemann problem instead of the original one. This strategy is applied to VFRoe solvers where we show that it ...

  8. Simple and High-Accurate Schemes for Hyperbolic Conservation Laws

    Directory of Open Access Journals (Sweden)

    Renzhong Feng

    2014-01-01

    Full Text Available The paper constructs a class of simple high-accurate schemes (SHA schemes with third order approximation accuracy in both space and time to solve linear hyperbolic equations, using linear data reconstruction and Lax-Wendroff scheme. The schemes can be made even fourth order accurate with special choice of parameter. In order to avoid spurious oscillations in the vicinity of strong gradients, we make the SHA schemes total variation diminishing ones (TVD schemes for short by setting flux limiter in their numerical fluxes and then extend these schemes to solve nonlinear Burgers’ equation and Euler equations. The numerical examples show that these schemes give high order of accuracy and high resolution results. The advantages of these schemes are their simplicity and high order of accuracy.

  9. Numerical schemes for solving the Euler equations of gas dynamics

    International Nuclear Information System (INIS)

    The first-order upwind schemes of Godunov-Van Leer, Steger-Warming, Godunov, Roe, Osher and Glimm; Godunov type scheme I; the second-order upwind schemes of Van Leer, Fromm-Van Leer, Hancock-Van Leer, and Moretti; and the second-order centered schemes of Richtmyer, Mac Cormack, Lerat-Peyrat, and Jameson are described. Their performances for the shock-tube problem proposed by Sod are compared. The schemes of Godunov-Van Leer, Glimm, Fromm-Van Leer, and Hancock-Van Leer produced the best results. All the First-order upwind schemes, the Glimm scheme, the Jameson scheme, and the Hancock-Van Leer scheme can be extended to two dimensions in the finite element setting. 30 references

  10. An authentication scheme for secure access to healthcare services.

    Science.gov (United States)

    Khan, Muhammad Khurram; Kumari, Saru

    2013-08-01

    Last few decades have witnessed boom in the development of information and communication technologies. Health-sector has also been benefitted with this advancement. To ensure secure access to healthcare services some user authentication mechanisms have been proposed. In 2012, Wei et al. proposed a user authentication scheme for telecare medical information system (TMIS). Recently, Zhu pointed out offline password guessing attack on Wei et al.'s scheme and proposed an improved scheme. In this article, we analyze both of these schemes for their effectiveness in TMIS. We show that Wei et al.'s scheme and its improvement proposed by Zhu fail to achieve some important characteristics necessary for secure user authentication. We find that security problems of Wei et al.'s scheme stick with Zhu's scheme; like undetectable online password guessing attack, inefficacy of password change phase, traceability of user's stolen/lost smart card and denial-of-service threat. We also identify that Wei et al.'s scheme lacks forward secrecy and Zhu's scheme lacks session key between user and healthcare server. We therefore propose an authentication scheme for TMIS with forward secrecy which preserves the confidentiality of air messages even if master secret key of healthcare server is compromised. Our scheme retains advantages of Wei et al.'s scheme and Zhu's scheme, and offers additional security. The security analysis and comparison results show the enhanced suitability of our scheme for TMIS. PMID:23828650

  11. A novel cell search scheme for OFDM cellular systems

    Institute of Scientific and Technical Information of China (English)

    DING Ming; LUO Han-wen; WU Yun

    2007-01-01

    A novel cell search scheme for OFDM cellular systems is proposed. It is based on one OFDM symbol with several identical slots as preamble, the time domain repetition structure of which can be utilized to accomplish OFDM timing/frequency synchronization. The cell ID is comprised of two parts: a sub-carrier mask index g and a sequence index x. Each sub-carrier mask activates or deactivates some of the sub-carriers, after which a differentially coded sequence is loaded on pairs of the adjacent active sub-carriers. The user equipment (UE) recognizes the mask with index g via power detection of the received frequency domain signal. Then it estimates the index x from differential demodulation followed by detection of the frequency domain sequence. In order to improve the performance, a method of jointly estimating g and x is devised. Simulation results showed that the proposed scheme is able to support a very large number of cell IDs while maintaining a good performance even in bad multi-cell environment.

  12. Fuzzy Logic Controller Scheme for Floor Vibration Control

    Directory of Open Access Journals (Sweden)

    Nyawako Donald Steve

    2015-01-01

    Full Text Available The design of civil engineering floors is increasingly being governed by their vibration serviceability performance. This trend is the result of advancements in design technologies offering designers greater flexibilities in realising more lightweight, longer span and more open-plan layouts. These floors are prone to excitation from human activities. The present research work looks at analytical studies of active vibration control on a case study floor prototype that has been specifically designed to be representative of a real office floor structure. Specifically, it looks at tuning fuzzy control gains with the aim of adapting them to measured structural responses under human excitation. Vibration mitigation performances are compared with those of a general velocity feedback controller, and these are found to be identical in these sets of studies. It is also found that slightly less control force is required for the fuzzy controller scheme at moderate to low response levels and as a result of the adaptive gain, at very low responses the control force is close to zero, which is a desirable control feature. There is also saturation in the peak gain with the fuzzy controller scheme, with this gain tending towards the optimal feedback gain of the direct velocity feedback (DVF at high response levels for this fuzzy design.

  13. Hedge algorithm and Dual Averaging schemes

    CERN Document Server

    Baes, Michel

    2011-01-01

    We show that the Hedge algorithm, a method that is widely used in Machine Learning, can be interpreted as a particular instance of Dual Averaging schemes, which have recently been introduced by Nesterov for regret minimization. Based on this interpretation, we establish three alternative methods of the Hedge algorithm: one in the form of the original method, but with optimal parameters, one that requires less a priori information, and one that is better adapted to the context of the Hedge algorithm. All our modified methods have convergence results that are better or at least as good as the performance guarantees of the vanilla method. In numerical experiments, our methods significantly outperform the original scheme.

  14. Local discrimination scheme for some unitary operations

    Science.gov (United States)

    Cao, TianQing; Gao, Fei; Tian, GuoJing; Xie, ShuCui; Wen, QiaoYan

    2016-09-01

    It has been shown that for two different multipartite unitary operations U 1 and U 2, when tr( U 1 † U 2) = 0, they can always be perfectly distinguished by local operations and classical communication in the single-run scenario. However, how to find the detailed scheme to complete the local discrimination is still a fascinating problem. In this paper, aiming at some U 1 and U 2 acting on the bipartite and tripartite space respectively, especially for U 1 † U 2 locally unitary equivalent to the high dimensional X-type hermitian unitary matrix V with tr V = 0, we put forward the explicit local distinguishing schemes in the single-run scenario.

  15. Fixed Wordsize Implementation of Lifting Schemes

    Directory of Open Access Journals (Sweden)

    Tanja Karp

    2007-01-01

    Full Text Available We present a reversible nonlinear discrete wavelet transform with predefined fixed wordsize based on lifting schemes. Restricting the dynamic range of the wavelet domain coefficients due to a fixed wordsize may result in overflow. We show how this overflow has to be handled in order to maintain reversibility of the transform. We also perform an analysis on how large a wordsize of the wavelet coefficients is needed to perform optimal lossless and lossy compressions of images. The scheme is advantageous to well-known integer-to-integer transforms since the wordsize of adders and multipliers can be predefined and does not increase steadily. This also results in significant gains in hardware implementations.

  16. Evaluating Parsing Schemes with Entropy Indicators

    CERN Document Server

    Lyon, C; Lyon, Caroline; Brown, Stephen

    1997-01-01

    This paper introduces an objective metric for evaluating a parsing scheme. It is based on Shannon's original work with letter sequences, which can be extended to part-of-speech tag sequences. It is shown that this regular language is an inadequate model for natural language, but a representation is used that models language slightly higher in the Chomsky hierarchy. We show how the entropy of parsed and unparsed sentences can be measured. If the entropy of the parsed sentence is lower, this indicates that some of the structure of the language has been captured. We apply this entropy indicator to support one particular parsing scheme that effects a top down segmentation. This approach could be used to decompose the parsing task into computationally more tractable subtasks. It also lends itself to the extraction of predicate/argument structure.

  17. OPERATIONAL MODAL ANALYSIS SCHEMES USING CORRELATION TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    Zheng Min; Shen Fan; Chen Huaihai

    2005-01-01

    For some large-scale engineering structures in operating conditions, modal parameters estimation must base itself on response-only data. This problem has received a considerable amount of attention in the past few years. It is well known that the cross-correlation function between the measured responses is a sum of complex exponential functions of the same form as the impulse response function of the original system. So this paper presents a time-domain operating modal identification global scheme and a frequency-domain scheme from output-only by coupling the cross-correlation function with conventional modal parameter estimation. The outlined techniques are applied to an airplane model to estimate modal parameters from response-only data.

  18. Verifiable threshold signature schemes against conspiracy attack

    Institute of Scientific and Technical Information of China (English)

    GAN Yuan-ju(甘元驹)

    2004-01-01

    In this study, the author has designed new verifiable (t,n) threshold untraceable signature schemes. The proposed schemes have the following properties:(1) Verification: The shadows of the secret distributed by the trusted center can be verified by all of the participants;(2) Security: Even if the number of the dishonest member is over the value of the threshold, they cannot get the system secret parameters ,such as the group secret key, and forge other member's individual signature;(3) Efficient verification: The verifier can verify the group signature easily and the verification time of the group signature is equivalent to that of an individual signature; (4) Untraceability: The signers of the group signature cannot be traced.

  19. Verifiable threshold signature schemes against conspiracy attack

    Institute of Scientific and Technical Information of China (English)

    甘元驹

    2004-01-01

    In this study, the author has designed new verifiable (t, n) threshold untraceable signature schemes. The proposed schemes have the following properties: ( 1 ) Verification: The shadows of the secret distributed by the trusted center can be verified by all of the participants; (2) Security: Even if the number of the dishonest member is over the value of the threshold, they cannot get the system secret parameters , such as the group secret key, and forge other member's individual signature; (3) Efficient verification: The verifier can verify the group signature easily and the verification time of the group signature is equivalent to that of an individual signature; (4) Untraceability: The signers of the group signature cannot be traced.

  20. Cryptanalysis to a Certificateless Threshold Signature Scheme

    Directory of Open Access Journals (Sweden)

    Wenjie Yang

    2012-10-01

    Full Text Available Certificateless public key cryptography is a new paradigm with two interesting features. On one hand, it keeps the certificate free property of identity-based public key cryptography (ID-PKC, while on the other hand, it gets rid of the inherent key escrow problem of ID-PKC. These two distinctive features make certificateless threshold signature schemes more applicable in practice as it removes the cost of transmitting and verifying the public key certificates of the participants who are involved in signing, and yet without the fear of key escrow. In this paper, we analyze the security of an existing certificateless threshold signature (CLTHS scheme recently proposed by Zhong et al.[26]. We show it is insure by demonstrating its three security drawbacks. Especially, we present a kind of public key replacement attack against it. Our attack reveals that it is subject to universal forgeries of type I adversaries

  1. Integrating Standard Dependency Schemes in QCSP Solvers

    Institute of Scientific and Technical Information of China (English)

    Ji-Wei Jin; Fei-Fei Ma; Jian Zhang

    2012-01-01

    Quantified constraint satisfaction problems (QCSPs) are an extension to constraint satisfaction problems (CSPs) with both universal quantifiers and existential quantifiers.In this paper we apply variable ordering heuristics and integrate standard dependency schemes in QCSP solvers.The technique can help to decide the next variable to be assigned in QCSP solving.We also introduce a new factor into the variable ordering heuristics:a variable's dep is the number of variables depending on it.This factor represents the probability of getting more candidates for the next variable to be assigned.Experimental results show that variable ordering heuristics with standard dependency schemes and the new factor dep can improve the performance of QCSP solvers.

  2. Cartesian Grid Method for Gas Kinetic Scheme

    CERN Document Server

    Chen, Songze; Li, Zhihui

    2015-01-01

    A Cartesian grid method combined with a simplified gas kinetic scheme is presented for subsonic and supersonic viscous flow simulation on complex geometries. Under the Cartesian mesh, the computational grid points are classified into four different categories, the fluid point, the solid point, the drop point, and the interpolation point. The boundaries are represented by a set of direction-oriented boundary points. A constrained weighted least square method is employed to evaluate the physical quantities at the interpolation points. Different boundary conditions, including isothermal boundary, adiabatic boundary, and Euler slip boundary, are presented by different interpolation strategies. We also propose a simplified gas kinetic scheme as the flux solver for both subsonic and supersonic flow computations. The methodology of constructing a simplified kinetic flux function can be extended to other flow systems. A few numerical examples are used to validate the Cartesian grid method and the simplified flux func...

  3. Employee Share Option Scheme And Employees’ Motivation

    Directory of Open Access Journals (Sweden)

    Rebecca Yew Ming Yian

    2011-06-01

    Full Text Available Employee stock options scheme (ESOS is a call option on the ordinary share of a company, issued as a form of non-cash compensation or as an incentive tool. ESOS gives an employee the right to buy shares at a fixed price for a defined number of years into the future. The trend toward broad-based share options may come to an end as companies are scaling back due to the changes in accounting standards. Similarly, companies in Malaysia, especially in the banking industry which originally offered share options to their employees are now pulling back this scheme. Does the movement to scale back share options affect employees’ motivation? This is an empirical question which this paper intends to explore. It is hope that the commercial banks will reconsider offering ESOS in rewarding their employees if the research finding indicates that it plays a significant role in motivating employees.

  4. A GENERALIZED CLASS OF PSNR SAMPLING SCHEME

    Directory of Open Access Journals (Sweden)

    D. Shukla

    2010-01-01

    Full Text Available In the present days of advanced electronic technologies in the field of communicationlike mobile phones, e-mail, internet etc. (and so forth the incentive based mail surveys are beingpopular due to their cost effectiveness and rapid approach to individuals. But, a majordisadvantage appears as mail surveys are affected by a huge amount of non-response of units inthe sample. The post-stratified non-response (PSNR scheme is used, in the stratified samplingset-up, when (i frames of stratum are unknown and (ii strata contain some non-responding units.This paper presents a general class of PSNR type sampling scheme by introducing three groupsof earmarked strata based on response pattern along-with two parameters pf the class. TheBayesian approach regarding utilization of prior knowledge (or guess of response pattern isintroduced in the proposed class for estimating the population mean. Several properties of theclass are derived and the results are numerically supported.

  5. Exclusion from the Health Insurance Scheme

    CERN Multimedia

    2003-01-01

    A CERN pensioner, member of the Organization's Health Insurance Scheme (CHIS), recently provided fake documents in support of claims for medical expenses, in order to receive unjustified reimbursement from the CHIS. The Administrator of the CHIS, UNIQA, suspected a case of fraud: Accordingly, an investigation and interview of the person concerned was carried out and brought the Organization to the conclusion that fraud had actually taken place. Consequently and in accordance with Article VIII 3.12 of the CHIS Rules, it was decided to exclude this member permanently from the CHIS. The Organization takes the opportunity to remind Scheme members that any fraud or attempt to fraud established within the framework of the CHIS exposes them to: - disciplinary action, according to the Staff Rules and Regulations, for CERN members of the personnel; - definitive exclusion from the CHIS for members affiliated on a voluntary basis. Human Resources Division Tel. 73635

  6. Properly designed emissions trading schemes do work!

    OpenAIRE

    Carmona, Rene; Fehr, Max; Hinz, Juri

    2009-01-01

    Emissions trading markets have been touted as the most efficient mechanism to achieve environmental goals at least cost. Whether in the form of voluntary markets or in a mandatory framework like in the first phase of the European Union (EU) Emission Trading Scheme (ETS), the regulator sets a cap on the emissions which can occur without penalty, and provides emissions allowances accordingly. The recipients are free to use these emission certificates to cover their emissions, or to sell them...

  7. Communication Scheme via Cascade Chaotic Systems

    Institute of Scientific and Technical Information of China (English)

    HUA Chang-Chun; GUAN Xin-Ping

    2004-01-01

    @@ A new chaotic communication scheme is constructed. Different from the existing literature, cascade chaotic systems are employed. Two cascade modes are considered. First, we investigate the input to state cascade mode;cascade systems between different kinds of chaotic systems are considered. Then the parameter cascade case of chaotic system is studied. Under the different cases, the corresponding receivers are designed, which can succeed in recovering the former emitted signal. Simulations are performed to verify the validity of the proposed main results.

  8. Lean mainstream schemes for Stata 8 graphics

    OpenAIRE

    Svend Juul

    2003-01-01

    The new Stata 8 graphics are powerful and flexible. Now, a few months after the first release, the graphics still have some shortcomings-both in design and in the manual documenting the program-but progress is being made. The graph layout used throughout the Graphics Reference Manual has led some users to underestimate the potential of the program. This paper presents two schemes for a lean layout, conforming to the mainstream in scientific publishing. Copyright 2003 by StataCorp LP.

  9. Thermodynamic scheme of inhomogeneous perfect fluid mixtures

    OpenAIRE

    Zarate, R D; Quevedo, Hernando

    2004-01-01

    We analyze the compatibility between the geometrodynamics and thermodynamics of a binary mixture of perfect fluids which describe inhomogeneous cosmological models. We generalize the thermodynamic scheme of general relativity to include the chemical potential of the fluid mixture with non-vanishing entropy production. This formalism is then applied to the case of Szekeres and Stephani families of cosmological models. The compatibility conditions turn out to impose symmetry conditions on the c...

  10. Droop Scheme With Consideration of Operating Costs

    DEFF Research Database (Denmark)

    Nutkani, I. U.; Loh, Poh Chiang; Blaabjerg, Frede

    2014-01-01

    Although many droop schemes have been proposed for distributed generator (DG) control in a microgrid, they mainly focus on achieving proportional power sharing based on the DG kVA ratings. Other factors like generation costs, efficiencies, and emission penalties at different loads have not been...... state will meet the intended objectives, as demonstrated in the experiment with a defined objective of minimizing the total microgrid operating cost....

  11. A simple Cartesian scheme for compressible multimaterials

    CERN Document Server

    Gorsse, Yannick; Milcent, Thomas; TELIB, Haysam

    2014-01-01

    We present a simple numerical method to simulate the interaction of two non-miscible compressible materials separated by an interface. The media considered may have significantly different physical properties and constitutive laws, describing for example fluids or hyperelastic solids. The model is fully Eulerian and the scheme is the same for all materials. We show stiff numerical illustrations in case of gas--gas, gas--water, gas--elastic solid interactions in the large deformation regime.

  12. Efficient Scheme for Chemical Flooding Simulation

    Directory of Open Access Journals (Sweden)

    Braconnier Benjamin

    2014-07-01

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

  13. Configuration spaces over Hilbert schemes and applications

    CERN Document Server

    Dias, Danielle

    1996-01-01

    The main themes of this book are to establish the triple formula without any hypotheses on the genericity of the morphism, and to develop a theory of complete quadruple points, which is a first step towards proving the quadruple point formula under less restrictive hypotheses. This book should be of interest to graduate students and researchers in the field of algebraic geometry. The reader is expected to have some basic knowledge of enumerative algebraic geometry and pointwise Hilbert schemes.

  14. Parasitology: United Kingdom National Quality Assessment Scheme.

    OpenAIRE

    Hawthorne, M; Chiodini, P L; Snell, J J; Moody, A H; Ramsay, A

    1992-01-01

    AIMS: To assess the results from parasitology laboratories taking part in a quality assessment scheme between 1986 and 1991; and to compare performance with repeat specimens. METHODS: Quality assessment of blood parasitology, including tissue parasites (n = 444; 358 UK, 86 overseas), and faecal parasitology, including extra-intestinal parasites (n = 205; 141 UK, 64 overseas), was performed. RESULTS: Overall, the standard of performance was poor. A questionnaire distributed to participants sho...

  15. Security Analysis of Electronic Identity Schemes

    OpenAIRE

    Amdam, Eli Sofie Finnøy

    2009-01-01

    This report is about electronic identity (eID) schemes and a security analysis in the Universal Composable (UC) security framework of Transport Layer Security (TLS) and OpenID. The security analysis show that secure communication session (scs) is realized by Transport Layer Security where TLS is the composition of the key exchange functionality with the message transmission of TLS record Layer. We also show that a TLS protocol, which is a composite protocol with the scs functionality, UC-real...

  16. Password Authentication Based on Fractal Coding Scheme

    OpenAIRE

    Al-Saidi, Nadia M. G.; Mohamad Rushdan Md. Said; Othman, Wan Ainun M.

    2012-01-01

    Password authentication is a mechanism used to authenticate user identity over insecure communication channel. In this paper, a new method to improve the security of password authentication is proposed. It is based on the compression capability of the fractal image coding to provide an authorized user a secure access to registration and login process. In the proposed scheme, a hashed password string is generated and encrypted to be captured together with the user identity using text to image ...

  17. A Proactive Maintenance Scheme for Wireless Systems

    OpenAIRE

    Walsh, Barbara; Farrell, Ronan

    2008-01-01

    In the wireless sector maintenance costs form a large part of the total network operating cost. This paper presents a proactive maintenance scheme for wireless systems which is aimed at reducing the high operational costs encountered in the wireless industry by decreasing maintenance costs and system downtime. An on-line monitoring system is used to identify performance degradation, as well as its possible sources via symbol frequency distribution analysis. It ensures that maintenance occurs ...

  18. Review of the Nursing Home Subvention Scheme

    OpenAIRE

    Department of Health

    2003-01-01

    Review of the Nursing Home Subvention Scheme The government decided in 1997 to approve proposals from the Minister for Finance for a process of expenditure reviews as a key part of the financial management systems that are central to the Strategic Management Initiative and are intended to ensure greater predictability in resource planning. The aims of the expenditure review process are as follows: Click here to download PDF 873kb

  19. Conservation agriculture is shaped through advisory schemes

    OpenAIRE

    Brives, Hélène; Riousset, Pauline; de Tourdonnet, Stephane

    2012-01-01

    This communication challenges the idea that participatory extension methods are required to develop more sustainable forms of agriculture. It is based on a comparison of two case studies presenting how Conservation Agriculture is promoted by a French agribusiness company. In one case a participatory extension scheme is organized when in the second case CA is promoted through technology transfer. The paper explores how do CA practices evolve when developed through participatory and non partici...

  20. Welfare Schemes and Social Protection in India

    OpenAIRE

    Raghbendra Jha

    2013-01-01

    This paper provides a broad overview of welfare schemes in India and their impact on social protection during a period of high economic growth. It summarizes India's performance with respect to select economic and social indicators relative to select low and middle income countries in the Asia Pacific region. It further overviews trends in some key select economic and social indicators for India and discusses India's attainment in Social Protection relative to an index of such protection prov...

  1. An iterative initialization scheme for mesoscale studies

    OpenAIRE

    Rao, G. V.; Fisherman, J.

    2011-01-01

    An iterative technique to produce an initial set of consistent meteorological variables on a mesoscale basis is constructed. The development follows closely the earlier pioneering study of Miyakoda & Moyer (1968) who examined the feasibility of such a technique for synoptic scale initialization utilizing the linearized barotropic equations. The proposed scheme, on the other hand, employs the primitive equations of motion and emphasizes the three-dimensional structure. Another difference i...

  2. INFORMATION FROM THE CERN HEALTH INSURANCE SCHEME

    CERN Multimedia

    Tel : 7-3635

    2002-01-01

    Please note that, from 1 July 2002, the tariff agreement between CERN and the Hôpital de la Tour will no longer be in force. As a result the members of the CERN Health Insurance Scheme will no longer obtain a 5% discount for quick payment of bills. More information on the termination of the agreement and the implications for our Health Insurance Scheme will be provided in the next issue of the CHIS Bull', due for publication in the first half of July. It will be sent to your home address, so, if you have moved recently, please check that your divisional secretariat has your current address. Tel.: 73635 The Organization's Health Insurance Scheme (CHIS) has launched its own Web pages, located on the Website of the Social & Statutory Conditions Group of HR Division (HR-SOC). The address is short and easy-to-remember www.cern.ch/chis The pages currently available concentrate on providing basic information. Over the coming months it is planned to fill out the details and introduce new topics. Please give us ...

  3. Log-scaling magnitude modulated watermarking scheme

    Institute of Scientific and Technical Information of China (English)

    LING HeFei; YUAN WuGang; ZOU FuHao; LU ZhengDing

    2007-01-01

    A real-time watermarking scheme with high robustness and security has been proposed based on modulating the log-scaling magnitudes of DCT coefficients,which is most suitable for JPEG images and MPEG streams. The watermark bit is encoded as the sign of the difference between the individual log-scaling magnitude of a group-region and the average one of all group-regions. The log-scaling magnitude can be modulated by modifying the low and middle frequency DCT coefficients imperceptibly. The robustness of scheme is not only dependent on those largest coefficients, but also on the other coefficients with the same proportion. It can embed 512 bits into an image with a size of 512×512, which can satisfy the payload requirement of most video watermarking applications. Moreover, the watermark embedding process only requires one-sixth of the time consumed during normal playing of video, and the watermark detection only requires one-twelfth of that, which can meet the real-time requirements of most video watermarking applications. Furthermore, the experimental results show that the presented scheme is transparent and robust to significant valumetric distortions (including additive noise, low-pass filtering, lossy compression and valumetric scaling) and a part of geometric distortions. It performs much better than the EMW algorithm in resisting all kinds of distortions except Gaussian noise with a larger deviation.

  4. Generalized support varieties for finite group schemes

    CERN Document Server

    Friedlander, Eric M

    2011-01-01

    We construct two families of refinements of the (projectivized) support variety of a finite dimensional module $M$ for a finite group scheme $G$. For an arbitrary finite group scheme, we associate a family of {\\it non maximal rank varieties} $\\Gamma^j(G)_M$, $1\\leq j \\leq p-1$, to a $kG$-module $M$. For $G$ infinitesimal, we construct a finer family of locally closed subvarieties $V^{\\ul a}(G)_M$ of the variety of one parameter subgroups of $G$ for any partition $\\ul a$ of $\\dim M$. For an arbitrary finite group scheme $G$, a $kG$-module $M$ of constant rank, and a cohomology class $\\zeta$ in $\\HHH^1(G,M)$ we introduce the {\\it zero locus} $Z(\\zeta) \\subset \\Pi(G)$. We show that $Z(\\zeta)$ is a closed subvariety, and relate it to the non-maximal rank varieties. We also extend the construction of $Z(\\zeta)$ to an arbitrary extension class $\\zeta \\in \\Ext^n_G(M,N)$ whenever $M$ and $N$ are $kG$-modules of constant Jordan type.

  5. New scheme of optical switch technology of time division

    Institute of Scientific and Technical Information of China (English)

    GAO Ze-hua; QI Yong-xing; JI Yue-feng; QIAN Zong-jue

    2006-01-01

    The optical time division switch scheme using optical scanning was proposed in this paper.Quick switching can be realized by the optical element and optical system based on the proposed scheme.The modulation velocity of the proposed scheme can be of the order of nanosecond,which is quick enough for the next generation of optical communication.This scheme will be a key technology in the optical network.The principle of the scheme is studied.The structure of the scheme is proposed and the performance is analyzed.

  6. Implicit Upwind Schemes for Low Mach Number Compressible Flows

    OpenAIRE

    Viozat, Cécile

    1997-01-01

    At low Mach number, the Roe scheme presents an excess of artificial viscosity. A correction of this scheme, which uses the preconditioning of Turkel, leads to an improvement of the solution. We refer to this new scheme as the Roe-Turkel scheme. We show that for the Roe-Turkel scheme the convergence of the numerical solution towards the exact solution depends only on the mesh size parameter whereas that of the Roe scheme depends on the ratio between mesh size parameter and Mach number. We also...

  7. Cryptanalytic Performance Appraisal of Improved CCH2 Proxy Multisignature Scheme

    Directory of Open Access Journals (Sweden)

    Raman Kumar

    2014-01-01

    Full Text Available Many of the signature schemes are proposed in which the t out of n threshold schemes are deployed, but they still lack the property of security. In this paper, we have discussed implementation of improved CCH1 and improved CCH2 proxy multisignature scheme based on elliptic curve cryptosystem. We have represented time complexity, space complexity, and computational overhead of improved CCH1 and CCH2 proxy multisignature schemes. We have presented cryptanalysis of improved CCH2 proxy multisignature scheme and showed that improved CCH2 scheme suffered from various attacks, that is, forgery attack and framing attack.

  8. Constructing of constraint preserving scheme for Einstein equations

    CERN Document Server

    Tsuchiya, Takuya

    2016-01-01

    We propose a new numerical scheme of evolution for the Einstein equations using the discrete variational derivative method (DVDM). We derive the discrete evolution equation of the constraint using this scheme and show the constraint preserves in the discrete level. In addition, to confirm the numerical stability using this scheme, we perform some numerical simulations by discretized equations with the Crank-Nicolson scheme and with the new scheme, and we find that the new discretized equations have better stability than that of the Crank-Nicolson scheme.

  9. Quality Model of Foodstuff in the Control of Refrigerated Display Cabinet

    DEFF Research Database (Denmark)

    Cai, Junping; Risum, Jørgen; Thybo, Claus

    2006-01-01

    happens to the food inside during this period, when we look at the quality factor? This paper discusses quality model of foodstuff, different scenarios of defrost scheme are simulated, questions such as how the defrost temperature and duration influence the food temperature, thus the food quality, as well...... as what is the optimal defrost scheme from food quality point of view are answered. This will serve as a prerequisite of designing of optimal control scheme for the commercial refrigeration system, aiming at optimizing a weighed cost function of both food quality and overall energy consumption of system....

  10. Quality Model of Foodstuff in a Refrigerated Display Cabinet

    DEFF Research Database (Denmark)

    Cai, Junping; Risum, Jørgen; Thybo, Claus

    2006-01-01

    happens to the food inside during this period, when we look at the quality factor? This paper discusses quality model of foodstuff, different scenarios of defrost scheme are simulated, questions such as how the defrost temperature and duration influence the food temperature, thus the food quality, as well...... as what is the optimal defrost scheme from food quality point of view are answered. This will serve as a prerequisite of designing of optimal control scheme for the commercial refrigeration system, aiming at optimizing a weighed cost function of both food quality and overall energy consumption of system....

  11. CERN Health Insurance Scheme (CHIS) Contributions – Changes for 2012

    CERN Multimedia

    HR Department

    2012-01-01

    Following the 2010 five-yearly review of financial and social conditions, which included the CERN Health Insurance Scheme (CHIS), the CERN Council decided in December 2010 to progressively increase the level of contributions over the period 2011-2015.   For 2012, the contribution rate of active and retired CHIS members will be 4.41%. The amounts of the fixed premiums for voluntarily insured members (e.g. users and associates) as well as the supplementary contributions for spouses with income from a professional activity increase accordingly : Voluntary contributions The full contribution based on Reference Salary II is now 1094 CHF per month. This fixed amount contribution is applied to voluntarily affiliated users and associates with normal coverage. Half of this amount (547 CHF) is applied to apprentices as well as to voluntarily affiliated users and associates with reduced coverage. Finally, an amount of 438 CHF is applied to children maintaining their insurance cover on a voluntary and tempo...

  12. Uncertainty of Microphysics Schemes in CRMs

    Science.gov (United States)

    Tao, W. K.; van den Heever, S. C.; Wu, D.; Saleeby, S. M.; Lang, S. E.

    2015-12-01

    Microphysics is the framework through which to understand the links between interactive aerosol, cloud and precipitation processes. These processes play a critical role in the water and energy cycle. CRMs with advanced microphysics schemes have been used to study the interaction between aerosol, cloud and precipitation processes at high resolution. But, there are still many uncertainties associated with these microphysics schemes. This has arisen, in part, from the fact microphysical processes cannot be measured directly; instead, cloud properties, which can be measured, are and have been used to validate model results. The utilization of current and future global high-resolution models is rapidly increasing and are at what has been traditional CRM resolutions and are using microphysics schemes that were developed in traditional CRMs. A potential NASA satellite mission called the Cloud and Precipitation Processes Mission (CaPPM) is currently being planned for submission to the NASA Earth Science Decadal Survey. This mission could provide the necessary global estimates of cloud and precipitation properties with which to evaluate and improve dynamical and microphysical parameterizations and the feedbacks. In order to facilitate the development of this mission, CRM simulations have been conducted to identify microphysical processes responsible for the greatest uncertainties in CRMs. In this talk, we will present results from numerical simulations conducted using two CRMs (NU-WRF and RAMS) with different dynamics, radiation, land surface and microphysics schemes. Specifically, we will conduct sensitivity tests to examine the uncertainty of the some of the key ice processes (i.e. riming, melting, freezing and shedding) in these two-microphysics schemes. The idea is to quantify how these two different models' respond (surface rainfall and its intensity, strength of cloud drafts, LWP/IWP, convective-stratiform-anvil area distribution) to changes of these key ice

  13. An Energy Efficient Mutual Authentication and Key Agreement Scheme Preserving Anonymity for Wireless Sensor Networks.

    Science.gov (United States)

    Lu, Yanrong; Li, Lixiang; Peng, Haipeng; Yang, Yixian

    2016-01-01

    WSNs (Wireless sensor networks) are nowadays viewed as a vital portion of the IoTs (Internet of Things). Security is a significant issue in WSNs, especially in resource-constrained environments. AKA (Authentication and key agreement) enhances the security of WSNs against adversaries attempting to get sensitive sensor data. Various AKA schemes have been developed for verifying the legitimate users of a WSN. Firstly, we scrutinize Amin-Biswas's currently scheme and demonstrate the major security loopholes in their works. Next, we propose a lightweight AKA scheme, using symmetric key cryptography based on smart card, which is resilient against all well known security attacks. Furthermore, we prove the scheme accomplishes mutual handshake and session key agreement property securely between the participates involved under BAN (Burrows, Abadi and Needham) logic. Moreover, formal security analysis and simulations are also conducted using AVISPA(Automated Validation of Internet Security Protocols and Applications) to show that our scheme is secure against active and passive attacks. Additionally, performance analysis shows that our proposed scheme is secure and efficient to apply for resource-constrained WSNs. PMID:27338382

  14. Gender and power contestations over water use in irrigation schemes: Lessons from the lake Chilwa basin

    Science.gov (United States)

    Nkhoma, Bryson; Kayira, Gift

    2016-04-01

    Over the past two decades, Malawi has been adversely hit by climatic variability and changes, and irrigation schemes which rely mostly on water from rivers have been negatively affected. In the face of dwindling quantities of water, distribution and sharing of water for irrigation has been a source of contestations and conflicts. Women who constitute a significant section of irrigation farmers in schemes have been major culprits. The study seeks to analyze gender contestations and conflicts over the use of water in the schemes developed in the Lake Chilwa basin, in southern Malawi. Using oral and written sources as well as drawing evidence from participatory and field observations conducted at Likangala and Domasi irrigation schemes, the largest schemes in the basin, the study observes that women are not passive victims of male domination over the use of dwindling waters for irrigation farming. They have often used existing political and traditional structures developed in the management of water in the schemes to competitively gain monopoly over water. They have sometimes expressed their agency by engaging in irrigation activities that fall beyond the control of formal rules and regulations of irrigation agriculture. Other than being losers, women are winning the battle for water and land resources in the basin.

  15. An Energy Efficient Mutual Authentication and Key Agreement Scheme Preserving Anonymity for Wireless Sensor Networks

    Science.gov (United States)

    Lu, Yanrong; Li, Lixiang; Peng, Haipeng; Yang, Yixian

    2016-01-01

    WSNs (Wireless sensor networks) are nowadays viewed as a vital portion of the IoTs (Internet of Things). Security is a significant issue in WSNs, especially in resource-constrained environments. AKA (Authentication and key agreement) enhances the security of WSNs against adversaries attempting to get sensitive sensor data. Various AKA schemes have been developed for verifying the legitimate users of a WSN. Firstly, we scrutinize Amin-Biswas’s currently scheme and demonstrate the major security loopholes in their works. Next, we propose a lightweight AKA scheme, using symmetric key cryptography based on smart card, which is resilient against all well known security attacks. Furthermore, we prove the scheme accomplishes mutual handshake and session key agreement property securely between the participates involved under BAN (Burrows, Abadi and Needham) logic. Moreover, formal security analysis and simulations are also conducted using AVISPA(Automated Validation of Internet Security Protocols and Applications) to show that our scheme is secure against active and passive attacks. Additionally, performance analysis shows that our proposed scheme is secure and efficient to apply for resource-constrained WSNs. PMID:27338382

  16. Cryptanalysis and Improvement of Digital Multisignature Scheme Based on RSA

    Institute of Scientific and Technical Information of China (English)

    SU Li; CUI Guo-hua; CHEN Jing; YUAN Jun

    2007-01-01

    Zhang et al. proposed a sequential multisignature scheme based on RSA. The scheme has advantages of low computation and communication costs, and so on. However, we find a problem in their scheme that the verifier can not distinguish whether the multisignature is signed by all the signers of the group or only by the last signer. Thus, any single signature created by the last signer can be used as a multisignature created by the whole group members. This paper proposes an improved scheme that can overcome the defect. In the new scheme, the identity messages of all the signers are added in the multisignature and used in verification phase, so that the verifier can know the signature is generated by which signers. Performance analysis shows that the proposed scheme costs less computation than the original scheme in both signature and verification phases. Furthermore, each partial signature is based on the signer's identity certificate, which makes the scheme more secure.

  17. Threshold Signature Scheme Based on Discrete Logarithm and Quadratic Residue

    Institute of Scientific and Technical Information of China (English)

    FEI Ru-chun; WANG Li-na

    2004-01-01

    Digital signature scheme is a very important research field in computer security and modern cryptography.A(k,n) threshold digital signature scheme is proposed by integrating digital signature scheme with Shamir secret sharing scheme.It can realize group-oriented digital signature, and its security is based on the difficulty in computing discrete logarithm and quadratic residue on some special conditions.In this scheme, effective digital signature can not be generated by any k-1 or fewer legal users, or only by signature executive.In addition, this scheme can identify any legal user who presents incorrect partial digital signature to disrupt correct signature, or any illegal user who forges digital signature.A method of extending this scheme to an Abelian group such as elliptical curve group is also discussed.The extended scheme can provide rapider computing speed and stronger security in the case of using shorter key.

  18. Statistical Hiding Fuzzy Commitment Scheme for Securing Biometric Templates

    Directory of Open Access Journals (Sweden)

    Alawi A. Al-Saggaf

    2013-04-01

    Full Text Available By considering the security flaws in cryptographic hash functions, any commitment scheme designed straight through hash function usage in general terms is insecure. In this paper, we develop a general fuzzy commitment scheme called an ordinary fuzzy commitment scheme (OFCS, in which many fuzzy commitment schemes with variety complexity assumptions is constructed. The scheme is provably statistical hiding (the advisory gets almost no statistically advantages about the secret message. The efficiency of our scheme offers different security assurance, and the trusted third party is not involved in the exchange of commitment.The characteristic of our scheme makes it useful for biometrics systems. If the biometrics template is compromised, then there is no way to use it directly again even in secure biometrics systems. This paper combines biometrics and OFCS to achieve biometric protection scheme using smart cards with renewability of protected biometrics template property.

  19. An improved identity-based proxy ring signature scheme

    Institute of Scientific and Technical Information of China (English)

    Lang Weimin; Yang Zongkai; Cheng Wenqing; Tan Yunmeng

    2005-01-01

    Proxy ring signature schemes have been shown to be useful in various applications, such as electronic polling, electronic payment, etc. In this paper, we point out that Lang's scheme is unreasonable and propose an improved Identity-based proxy ring scheme from bilinear pairings which is reasonable and overcomes the deficiencies of Lang's scheme. Our scheme can prevent the original signer from generating the proxy ring signature, thus the profits of the proxy signer are guaranteed. In addition, our scheme satisfies all the security requirements of proxy ring signature, I.e. Signer-ambiguity, non-forgeability, verification, non-deniability and distinguishability. As compared with Zhang's scheme, our scheme is a computational efficiency improvement for signature verification because the computational cost of bilinear pairings required is reduced from O(n) to O(1).

  20. A SINGLE STEP SCHEME WITH HIGH ACCURACY FOR PARABOLIC PROBLEM

    Institute of Scientific and Technical Information of China (English)

    陈传淼; 胡志刚

    2001-01-01

    A single step scheme with high accuracy for solving parabolic problem is proposed. It is shown that this scheme possesses good stability and fourth order accuracy with respect to both time and space variables, which are superconvergent.

  1. Some high resolution numerical schemes for hydrodynamic equation integration

    International Nuclear Information System (INIS)

    We present here some high resolution schemes for gas dynamical simulations in on space dimension. In case of Eulerian coordinates the schemes are formulated as a lagrangian step followed by a remap. We insist on numerical results

  2. A NEW EFFICIENT ID-BASED PROXY BLIND SIGNATURE SCHEME

    Institute of Scientific and Technical Information of China (English)

    Ming Yang; Wang Yumin

    2008-01-01

    In a proxy blind signature scheme, the proxy signer is allowed to generate a blind signature on behalf of the original signer. The proxy blind signature scheme is useful in several applications such as e-voting, e-payment, etc. Recently, Zheng, et al. presented an IDentity (ID)-based proxy blind signature. In this paper, a new efficient ID-based proxy blind signature scheme from bilinear pairings is proposed, which can satisfy the security properties of both the proxy signatures and the blind signature schemes. Analysis of the scheme efficiency shows that the new scheme is more efficient than Zheng, et al.'s scheme. The proposed scheme is more practical in the real world.

  3. An asynchronous spike event coding scheme for programmable analog arrays

    OpenAIRE

    Gouveia, L.C.; Koickal, T.; Hamilton, A.

    2008-01-01

    This paper presents a spike event coding scheme for the communication of analog signals in programmable analog arrays. In the scheme presented here no events are transmitted when the signals are constant leading to low power dissipation and traffic reduction in analog arrays. The design process and the implementation of the scheme in a programmable array context are explained. The validation of the presented scheme is performed using a speech signal. Finally, we demonstrate how the event code...

  4. An Identity-Based Strong Designated Verifier Proxy Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    WANG Qin; CAO Zhenfu

    2006-01-01

    In a strong designated verifier proxy signature scheme, a proxy signer can generate proxy signature on behalf of an original signer, but only the designated verifier can verify the validity of the proxy signature. In this paper, we first define the security requirements for strong designated verifier proxy signature schemes. And then we construct an identity-based strong designated verifier proxy signature scheme. We argue that the proposed scheme satisfies all of the security requirements.

  5. Direct scheme for measuring the geometric quantum discord

    CERN Document Server

    Jin, Jia-sen; Yu, Chang-shui; Song, He-shan

    2011-01-01

    We propose a scheme to directly measure the exact value of geometric quantum discord of an arbitrary two-qubit state. We only need to perform the projective measurement in the all anti-symmetric subspace and our scheme is parametrically efficient in contrast to the widely adopted quantum state tomography scheme in the sense of less parameter estimations and projectors. Moreover, the present scheme can be easily realized with the current experimental techniques.

  6. Cryptanalysis and Improvement of Signcryption Schemes on Elliptic Curves

    Institute of Scientific and Technical Information of China (English)

    LI Xiang-xue; CHEN Ke-fei; LI Shi-qun

    2005-01-01

    In this paper, we analyze two signcryption schemes on elliptic curves proposed by Zheng Yu-liang and Hideki Imai. We point out a serious problem with the schemes that the elliptic curve based signcryption schemes lose confidentiality to gain non-repudiation. We also propose two improvement versions that not only overcome the security leak inherent in the schemes but also provide public verifiability or forward security. Our improvement versions require smaller computing cost than that required by signature-thenencryption methods.

  7. An Advanced Threshold Secret Sharing Scheme for Identifying Cheaters

    Institute of Scientific and Technical Information of China (English)

    XIE Shu-cui; ZHANG Jian-zhong

    2003-01-01

    In this paper an advanced threshold secret sharing scheme for identifying cheaters is proposed by using authentication codes. The performance of the scheme is discussed. The results show that in the scheme the valid shareholders can not only identify the impersonation of an adversary, but also detect cheating of some valid shareholders. In particular one honest shareholder is able to detect cheating of other participants forming a collection, and the information rate of the scheme is higher than that of others.

  8. Quantum Communication Scheme Using Non-symmetric Quantum Channel

    Institute of Scientific and Technical Information of China (English)

    CAO Hai-Jing; CHEN Zhong-Hua; SONG He-Shan

    2008-01-01

    A theoretical quantum communication scheme based on entanglement swapping and superdense coding is proposed with a 3-dimensional Bell state and 2-dimensional Bell state function as quantum channel quantum key distribution and quantum secure direct communication can be simultaneously accomplished in the scheme. The scheme is secure and has high source capacity. At last, we generalize the quantum communication scheme to d-dimensional quantum channel.

  9. A Structured Multi-signature Scheme Against Forgery Attack

    Directory of Open Access Journals (Sweden)

    Wenjun Luo

    2011-12-01

    Full Text Available There are some classic structured multi-signature programs, such as Burmester’s, Harn’s and Lin’s schemes that can not resist inside attack and outside attack. In this paper, we briefly review Burmester’s program and relate safety analysis, Burmester’s scheme vulnerable to forgery attack. Then we propose a structured multi-signature scheme against forgery attack. In the new scheme, we increase the signature parameter verification to improve security.

  10. Verifiable (t, n) Threshold Signature Scheme Based on Elliptic Curve

    Institute of Scientific and Technical Information of China (English)

    WANG Hua-qun; ZHAO Jun-xi; ZHANG Li-jun

    2005-01-01

    Based on the difficulty of solving the ECDLP (elliptic curve discrete logarithm problem) on the finite field,we present a (t, n) threshold signature scheme and a verifiable key agreement scheme without trusted party. Applying a modified elliptic curve signature equation, we get a more efficient signature scheme than the existing ECDSA (elliptic curve digital signature algorithm) from the computability and security view. Our scheme has a shorter key, faster computation, and better security.

  11. Accuracy analysis of Lagrangian Godunov scheme using variational theory

    OpenAIRE

    VAN WAGENINGEN-KESSELS,K; LECLERCQ,L; VUIK,K; Hoogendoorn, S.; VAN LIT,H

    2010-01-01

    The kinematic wave model is used to describe dynamic traffic flow. The model equations are solved using the Lagrangian Godunov scheme. Previously, this scheme has been found to be more accurate than the traditional Eulerian Godunov scheme. Furthermore, the variational theory has been applied to solve the model equations even more accurately and under certain conditions exactly. Therefore, it can be used as a benchmark. We analyse the global error of the Lagrangian Godunov scheme. This is the ...

  12. An Efficient Proactive RSA Scheme for Ad Hoc Networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Rui-shan; CHEN Ke-fei

    2007-01-01

    A proactive threshold signature scheme is very important to tolerate mobile attack in mobile ad hoc networks. In this paper, we propose an efficient proactive threshold RSA signature scheme for ad hoc networks. The scheme consists of three protocols: the initial secret share distribution protocol, the signature generation protocol and the secret share refreshing protocol. Our scheme has three advantages. First, the signature generation protocol is efficient. Second, the signature generation protocol is resilient. Third, the share refreshing protocol is efficient.

  13. SWOT Analysis of IP Multimedia Sub System Security Authentication Schemes

    OpenAIRE

    Bukhari, Syed Majid Ali Shah; Khan, Inayat Ullah

    2009-01-01

    SWOT analysis is performed on IMS security authentication schemes to demonstrate the effectiveness of each schemes in terms of multiple parameters and associated dependencies for users and network operators. Due to SWOT tool we have been able to describe strengths, weakness, opportunities and threats in each authentication scheme separately. The analysis performed mostly based on the state of art studies, SWOT tool itself approximates authentication schemes but in the discussion chapter we il...

  14. A new configurational bias scheme for sampling supramolecular structures

    Energy Technology Data Exchange (ETDEWEB)

    De Gernier, Robin; Mognetti, Bortolo M., E-mail: bmognett@ulb.ac.be [Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, Code Postal 231, Campus Plaine, B-1050 Brussels (Belgium); Curk, Tine [Department of Chemistry, University of Cambridge, Cambridge CB2 1EW (United Kingdom); Dubacheva, Galina V. [Biosurfaces Unit, CIC biomaGUNE, Paseo Miramon 182, 20009 Donostia - San Sebastian (Spain); Richter, Ralf P. [Biosurfaces Unit, CIC biomaGUNE, Paseo Miramon 182, 20009 Donostia - San Sebastian (Spain); Université Grenoble Alpes, DCM, 38000 Grenoble (France); CNRS, DCM, 38000 Grenoble (France); Max Planck Institute for Intelligent Systems, 70569 Stuttgart (Germany)

    2014-12-28

    We present a new simulation scheme which allows an efficient sampling of reconfigurable supramolecular structures made of polymeric constructs functionalized by reactive binding sites. The algorithm is based on the configurational bias scheme of Siepmann and Frenkel and is powered by the possibility of changing the topology of the supramolecular network by a non-local Monte Carlo algorithm. Such a plan is accomplished by a multi-scale modelling that merges coarse-grained simulations, describing the typical polymer conformations, with experimental results accounting for free energy terms involved in the reactions of the active sites. We test the new algorithm for a system of DNA coated colloids for which we compute the hybridisation free energy cost associated to the binding of tethered single stranded DNAs terminated by short sequences of complementary nucleotides. In order to demonstrate the versatility of our method, we also consider polymers functionalized by receptors that bind a surface decorated by ligands. In particular, we compute the density of states of adsorbed polymers as a function of the number of ligand–receptor complexes formed. Such a quantity can be used to study the conformational properties of adsorbed polymers useful when engineering adsorption with tailored properties. We successfully compare the results with the predictions of a mean field theory. We believe that the proposed method will be a useful tool to investigate supramolecular structures resulting from direct interactions between functionalized polymers for which efficient numerical methodologies of investigation are still lacking.

  15. Vehicle scheduling schemes for commercial and emergency logistics integration.

    Science.gov (United States)

    Li, Xiaohui; Tan, Qingmei

    2013-01-01

    In modern logistics operations, large-scale logistics companies, besides active participation in profit-seeking commercial business, also play an essential role during an emergency relief process by dispatching urgently-required materials to disaster-affected areas. Therefore, an issue has been widely addressed by logistics practitioners and caught researchers' more attention as to how the logistics companies achieve maximum commercial profit on condition that emergency tasks are effectively and performed satisfactorily. In this paper, two vehicle scheduling models are proposed to solve the problem. One is a prediction-related scheme, which predicts the amounts of disaster-relief materials and commercial business and then accepts the business that will generate maximum profits; the other is a priority-directed scheme, which, firstly groups commercial and emergency business according to priority grades and then schedules both types of business jointly and simultaneously by arriving at the maximum priority in total. Moreover, computer-based simulations are carried out to evaluate the performance of these two models by comparing them with two traditional disaster-relief tactics in China. The results testify the feasibility and effectiveness of the proposed models. PMID:24391724

  16. Clarification of nuclear risk recognition scheme through dialogue forum

    International Nuclear Information System (INIS)

    The design framework and operational guidelines for conducting repetitive dialogue between public and nuclear engineers are described in this paper. An action research project named repetitive dialogue forum has been conducted in two municipalities where nuclear facilities were sited. The qualitative evaluation by public participants indicated that the public trust in the nuclear experts, known as the crucial factor for meaningful communication, was successfully established through the dialogue forum. In addition, the expert showed a marked psychological change from distrust to trust in public. Through a detailed analysis of the comments of the participants raised during the forums, the nuclear risk recognition scheme of the public was clarified. The constituents of the risk recognition scheme about nuclear facilities were identified as follows. The first is related to the technical risk recognition factor including purely technical risk, organizational elements and regulatory elements. The second is the social risk recognition factor including economical and mental elements. The last is the communication factor including the influence of mass media, difficulty in frank communication in local community etc. It became clear that the information provision activities conducted by the government and the nuclear industry were lack of in-depth understanding of actual information needs in the public. Provision of information contents consistent with our observations is recommended for reestablishment of public trust in expert and for more informative dialogical interactions. (author)

  17. Vehicle scheduling schemes for commercial and emergency logistics integration.

    Science.gov (United States)

    Li, Xiaohui; Tan, Qingmei

    2013-01-01

    In modern logistics operations, large-scale logistics companies, besides active participation in profit-seeking commercial business, also play an essential role during an emergency relief process by dispatching urgently-required materials to disaster-affected areas. Therefore, an issue has been widely addressed by logistics practitioners and caught researchers' more attention as to how the logistics companies achieve maximum commercial profit on condition that emergency tasks are effectively and performed satisfactorily. In this paper, two vehicle scheduling models are proposed to solve the problem. One is a prediction-related scheme, which predicts the amounts of disaster-relief materials and commercial business and then accepts the business that will generate maximum profits; the other is a priority-directed scheme, which, firstly groups commercial and emergency business according to priority grades and then schedules both types of business jointly and simultaneously by arriving at the maximum priority in total. Moreover, computer-based simulations are carried out to evaluate the performance of these two models by comparing them with two traditional disaster-relief tactics in China. The results testify the feasibility and effectiveness of the proposed models.

  18. Saturation Detection-Based Blocking Scheme for Transformer Differential Protection

    Directory of Open Access Journals (Sweden)

    Byung Eun Lee

    2014-07-01

    Full Text Available This paper describes a current differential relay for transformer protection that operates in conjunction with a core saturation detection-based blocking algorithm. The differential current for the magnetic inrush or over-excitation has a point of inflection at the start and end of each saturation period of the transformer core. At these instants, discontinuities arise in the first-difference function of the differential current. The second- and third-difference functions convert the points of inflection into pulses, the magnitudes of which are large enough to detect core saturation. The blocking signal is activated if the third-difference of the differential current is larger than the threshold and is maintained for one cycle. In addition, a method to discriminate between transformer saturation and current transformer (CT saturation is included. The performance of the proposed blocking scheme was compared with that of a conventional harmonic blocking method. The test results indicate that the proposed scheme successfully discriminates internal faults even with CT saturation from the magnetic inrush, over-excitation, and external faults with CT saturation, and can significantly reduce the operating time delay of the relay.

  19. Regulatory schemes to achieve optimal flux partitioning in bacterial metabolism

    Science.gov (United States)

    Tang, Lei-Han; Yang, Zhu; Hui, Sheng; Kim, Pan-Jun; Li, Xue-Fei; Hwa, Terence

    2012-02-01

    The flux balance analysis (FBA) offers a way to compute the optimal performance of a given metabolic network when the maximum incoming flux of nutrient molecules and other essential ingredients for biosynthesis are specified. Here we report a theoretical and computational analysis of the network structure and regulatory interactions in an E. coli cell. An automated scheme is devised to simplify the network topology and to enumerate the independent flux degrees of freedom. The network organization revealed by the scheme enables a detailed interpretation of the three layers of metabolic regulation known in the literature: i) independent transcriptional regulation of biosynthesis and salvage pathways to render the network tree-like under a given nutrient condition; ii) allosteric end-product inhibition of enzyme activity at entry points of synthesis pathways for metabolic flux partitioning according to consumption; iii) homeostasis of currency and carrier compounds to maintain sufficient supply of global commodities. Using the amino-acid synthesis pathways as an example, we show that the FBA result can be reproduced with suitable implementation of the three classes of regulatory interactions with literature evidence.

  20. An Efficent Lossless Compression Scheme for ECG Signal

    Directory of Open Access Journals (Sweden)

    O. *El B’charri

    2016-07-01

    Full Text Available Cardiac diseases constitute the main cause of mortality around the globe. For detection and identification of cardiac problems, it is very important to monitor the patient's heart activities for long periods during his normal daily life. The recorded signal that contains information about the condition of the heart called electrocardiogram (ECG. As a result, long recording of ECG signal amounts to huge data sizes. In this work, a robust lossless ECG data compression scheme for real-time applications is proposed. The developed algorithm has the advantages of lossy compression without introducing any distortion to the reconstructed signal. The ECG signals under test were taken from the PTB Diagnostic ECG Database. The compression procedure is simple and provides a high compression ratio compared to other lossless ECG compression methods. The compressed ECG data is generated as a text file. The decompression scheme has also been developed using the reverse logic and it is observed that there is no difference between original and reconstructed ECG signal.

  1. Novel Fault Diagnosis Scheme for HVDC System via ESO

    Institute of Scientific and Technical Information of China (English)

    YAN Bing-yong; TIAN Zuo-hua; SHI Song-jiao

    2007-01-01

    A novel fault detection and identification (FDI) scheme for HVDC (High Voltage Direct Current Transmission) system was presented. It was based on the unique active disturbance rejection concept, where the HVDC system faults were estimated using an extended states observer (ESO). Firstly, the mathematical model of HVDC system was constructed, where the system states and disturbance were treated as an extended state. An augment HVDC system was established by using the extended state in rectify side and converter side, respectively. Then, a fault diagnosis filter was established to diagnose the HVDC system faults via the ESO theory. The evolution of the extended state in the augment HVDC system can reflect the actual system faults and disturbances, which can be used for the fault diagnosis purpose. A novel feature of this approach is that it can simultaneously detect and identify the shape and magnitude of the HVDC faults and disturbance. Finally, different kinds of HVDC faults were simulated to illustrate the feasibility and effectiveness of the proposed ESO based FDI approach. Compared with the neural network based or support vector machine based FDI approach, the ESO based FDI scheme can reduce the fault detection time dramatically and track the actual system fault accurately. What's more important, it needs not do complex online calculations and the training of neural network so that it can be applied into practice.

  2. Motion feature extraction scheme for content-based video retrieval

    Science.gov (United States)

    Wu, Chuan; He, Yuwen; Zhao, Li; Zhong, Yuzhuo

    2001-12-01

    This paper proposes the extraction scheme of global motion and object trajectory in a video shot for content-based video retrieval. Motion is the key feature representing temporal information of videos. And it is more objective and consistent compared to other features such as color, texture, etc. Efficient motion feature extraction is an important step for content-based video retrieval. Some approaches have been taken to extract camera motion and motion activity in video sequences. When dealing with the problem of object tracking, algorithms are always proposed on the basis of known object region in the frames. In this paper, a whole picture of the motion information in the video shot has been achieved through analyzing motion of background and foreground respectively and automatically. 6-parameter affine model is utilized as the motion model of background motion, and a fast and robust global motion estimation algorithm is developed to estimate the parameters of the motion model. The object region is obtained by means of global motion compensation between two consecutive frames. Then the center of object region is calculated and tracked to get the object motion trajectory in the video sequence. Global motion and object trajectory are described with MPEG-7 parametric motion and motion trajectory descriptors and valid similar measures are defined for the two descriptors. Experimental results indicate that our proposed scheme is reliable and efficient.

  3. A quantum identification scheme based on polarization modulation

    Institute of Scientific and Technical Information of China (English)

    He Guang-Qiang; Zeng Gui-Hua

    2005-01-01

    Aquantum idetification scheme including registration and identification phases is proposed.The user' passwords are transmitted by qubit string and recorded as set of quantum operators.The security of the proposed scheme is guarateed by the no-coloning theorem.Based on photon polarization modulation,an experimental approach is also designed to implement our proposed scheme.

  4. Scheme for Implementation of Quantum Game in Cavity QED

    International Nuclear Information System (INIS)

    We propose an experimentally feasible scheme to implement two-player quantum game in cavity quantum electrodynamics (QED). During the process, the cavity is only virtually excited, thus our scheme is insensitive to the cavity field states and cavity decay. The scheme can be realized in the range of current cavity QED techniques.

  5. General Scheme for the Construction of a Protected Qubit Subspace

    DEFF Research Database (Denmark)

    Aharon, N.; Drewsen, M.; Retzker, A.

    2013-01-01

    We present a new robust decoupling scheme suitable for half integer angular momentum states. The scheme is based on continuous dynamical decoupling techniques by which we create a protected qubit subspace. Our scheme predicts a coherence time of ~1 second, as compared to typically a few...

  6. Picard Groups and Class Groups of Monoid Schemes

    OpenAIRE

    Flores, Jaret; Weibel, Charles

    2013-01-01

    We define and study the Picard group of a monoid scheme and the class group of a normal monoid scheme. To do so, we develop some ideal theory for (pointed abelian) noetherian monoids, including primary decomposition and discrete valuations. The normalization of a monoid turns out to be a monoid scheme, but not always a monoid.

  7. A Formal Model for the Security of Proxy Signature Schemes

    Institute of Scientific and Technical Information of China (English)

    GU Chun-xiang; ZHU Yue-fei; ZHANG Ya-juan

    2005-01-01

    This paper provides theoretical foundations for the secure proxy signature primitive. We present a formal model for the security of proxy signature schemes, which defines the capabilities of the adversary and the security goals to capture which mean for a proxy signature scheme to be secure. Then, we present an example of proxy signature scheme that can be proven secure in the standard model.

  8. Scheme for Implementation of Quantum Game in Cavity QED

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-Chun; CAO Shu-Ai; WU Yue-Qin; FANG Mao-Fa; LI Huai-Fan; ZHENG Xiao-Juan; ZHAO Ren; WANG Xin-Wen; LI Ze-Hua

    2008-01-01

    We propose an experimentally feasible scheme to implement two-player quantum game in cavity quantum electrodynamics (QED). During the process, the cavity is only virtually excited, thus our scheme is insensitive to the cavity field states and cavity decay. The scheme can be realized in the range of current cavity QED techniques.

  9. 30 CFR 75.800-2 - Approved circuit schemes.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved circuit schemes. 75.800-2 Section 75... § 75.800-2 Approved circuit schemes. The following circuit schemes will be regarded as providing the necessary protection to the circuits required by § 75.800: (a) Ground check relays may be used...

  10. Linear Secret Sharing Schemes and Rearrangements of Access Structures

    Institute of Scientific and Technical Information of China (English)

    Liang-liang Xiao; Mu-lan Liu

    2004-01-01

    In this paper we study linear secret sharing schemes by monotone span programs, according to the relation between realizing access structures by linear secret sharing schemes and computing monotone Boolean functions by monotone span programs. Weconstruct some linear secret sharing schemes. Furthermore, we study the rearrangements of access structures that is very important in practice.

  11. Feasible schemes for preparing all five-photon graph states

    Institute of Scientific and Technical Information of China (English)

    Zhang Jin; Zhou Xiao-Qi; Yang Tao

    2007-01-01

    We propose feasible experimental schemes for preparing all five-photon graph states. Our schemes require only linear optical elements, photon detectors and post-selection, which are available in current experiment so that these schemes are within the reach of the current technology.

  12. Renormalization-scheme-independent perturbation theory by resumming logarithms

    OpenAIRE

    Dams, C.J.F.; Kleiss, R. H. P.

    2005-01-01

    Results of perturbation theory in quantum field theory generally depend on the renormalization scheme that is in use. In particular, they depend on the scale. We try to make perturbation theory scheme invariant by re-expanding with respect to a scheme invariant quantity. Furthermore, we investigate whether the potentially large logarithms in such an expansion cause inaccuracy and how this can be improved.

  13. Cryptanalysis of Two Fault Countermeasure Schemes

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey

    2015-01-01

    is meant for the protection of block ciphers like AES. The second countermeasure was proposed in IEEE-HOST 2015 and protects the Grain-128 stream cipher. The design divides the output function used in Grain-128 into two components. The first called the masking function, masks the input bits to the output......In this paper, we look at two fault countermeasure schemes proposed very recently in literature. The first proposed in ACISP 2015 constructs a transformation function using a cellular automata based linear diffusion, and a non-linear layer using a series of bent functions. This countermeasure...

  14. Key Management Scheme on Block Cipher

    DEFF Research Database (Denmark)

    Banoth, Rajkumar

    2012-01-01

    mechanism and the sudden absence of any node can’t cause breaking of whole security as the other nodes perform the job in the distributed environment. When computations related to cryptography are distributed, such system becomes more reliable and also fault tolerant. Therefore, this paper reviews research...... that has been carried out on encryption and decryption of text in block cipher. Then it also proposes a new cryptographic mechanism which is more secure and effective as it involves an efficient key management scheme. The experimental results revealed that the proposed mechanism is robust and can be...

  15. System Protection Schemes in Eastern Denmark

    OpenAIRE

    Rasmussen, Joana; Rønne-Hansen, Jan; Nielsen, Arne Hejde; Jørgensen, Preben; Havsager, Jan

    2006-01-01

    The Ph.D. project investigates different aspects of voltage stability in the power system ofEastern Denmark taking into account the large amount of wind power. In the project, a simpleSystem Protection Scheme (SPS) against voltage instability in Eastern Denmark is developed.The SPS design is based on static and dynamic simulation analyses using a large-scale model1that considers a number of realistic power system conditions. The southern part of the 132-kVsystem is prone to voltage stability ...

  16. Apiary B-Factory separation scheme

    International Nuclear Information System (INIS)

    A magnetic beam-separation scheme for an asymmetric-energy B-Factory based on the SLAC electron-positron collider PEP is described that has the following properties: the beams collide head-on and are separated magnetically with sufficient clearance at the parasitic crossing points and at the septum, the magnets have large beam-stay-clear apertures, synchrotron radiation produces low detector backgrounds and acceptable heat loads, and the peak β-function values and contributions to the chromaticities in the IR quadrupoles are moderate. 8 figs., 2 tabs

  17. Benefit Reentitlement Conditions in Unemployment Insurance Schemes

    DEFF Research Database (Denmark)

    Andersen, Torben M.; Christoffersen, Mark Strøm; Svarer, Michael

    Unemployment insurance schemes include conditions on past employment history as part of the eligibility conditions. This aspect is often neglected in the literature which primarily focuses on benefit levels and benefit duration. In a search-matching framework we show that benefit duration...... and employment requirements are substitute instruments in affecting job search incentives and thus gross unemployment. We analyse the optimal design of the unemployment insurance system (benefit levels, duration and employment requirements) under a utilitarian social welfare function. Simulations show...... that a higher insurance motive captured by more risk aversion implies higher benefit generosity and more lax employment requirements but also shortened benefit duration....

  18. DIFFERENCE SCHEMES BASING ON COEFFICIENT APPROXIMATION

    Institute of Scientific and Technical Information of China (English)

    MOU Zong-ze; LONG Yong-xing; QU Wen-xiao

    2005-01-01

    In respect of variable coefficient differential equations, the equations of coefficient function approximation were more accurate than the coefficient to be frozen as a constant in every discrete subinterval. Usually, the difference schemes constructed based on Taylor expansion approximation of the solution do not suit the solution with sharp function.Introducing into local bases to be combined with coefficient function approximation, the difference can well depict more complex physical phenomena, for example, boundary layer as well as high oscillatory, with sharp behavior. The numerical test shows the method is more effective than the traditional one.

  19. Advanced Coarsening Schemes for Graph Partitioning

    CERN Document Server

    Safro, Ilya; Schulz, Christian

    2012-01-01

    The graph partitioning problem is widely used and studied in many practical and theoretical applications. The multilevel strategies represent today one of the most effective and efficient generic frameworks for solving this problem on large-scale graphs. Most of the attention in designing the multilevel partitioning frameworks has been on the refinement phase. In this work we focus on the coarsening phase, which is responsible for creating structurally similar to the original but smaller graphs. We compare different matching- and AMG-based coarsening schemes, experiment with the algebraic distance between nodes, and demonstrate computational results on several classes of graphs that emphasize the running time and quality advantages of different coarsenings.

  20. Secure Biometric E-Voting Scheme

    Science.gov (United States)

    Ahmed, Taha Kh.; Aborizka, Mohamed

    The implementation of the e-voting becomes more substantial with the rapid increase of e-government development. The recent growth in communications and cryptographic techniques facilitate the implementation of e-voting. Many countries introduced e-voting systems; unfortunately most of these systems are not fully functional. In this paper we will present an e-voting scheme that covers most of the e-voting requirements, smart card and biometric recognition technology were implemented to guarantee voter's privacy and authentication.

  1. Constraint-Preserving Scheme for Maxwell's Equations

    CERN Document Server

    Tsuchiya, Takuya

    2016-01-01

    We derive the discretized Maxwell's equations using the discrete variational derivative method (DVDM), calculate the evolution equation of the constraint, and confirm that the equation is satisfied at the discrete level. Numerical simulations showed that the results obtained by the DVDM are superior to those obtained by the Crank-Nicolson scheme. In addition, we study the two types of the discretized Maxwell's equations by the DVDM and conclude that if the evolution equation of the constraint is not conserved at the discrete level, then the numerical results are also unstable.

  2. E6 Addressing Scheme and Network Architecture

    OpenAIRE

    Dmitry Anatolyevich Zaitsev; Sergey Ivanovich Bolshakov

    2012-01-01

    The paper describes new E6 addressing scheme for the creation of world-wide networks totally constructed on the base of Ethernet technology. Hierarchic E6 addresses with the length of 6 octets are used instead of both Ethernet MAC-addresses and IP-addresses that allows the routing within world-wide networks and cuts overhead of TCP, IP headers; the address space is extended in 16K times regarding IP addresses. Standard Ethernet LLC2 facilities are employed for guaranteed delivery of informati...

  3. ATLAS PhD Grant Scheme

    CERN Multimedia

    2016-01-01

    In this #CERNandSociety video, the 3 PhD students, awarded the ATLAS PhD Grant in 2015, talk about their research work within the ATLAS Collaboration and how this experience has shaped their future. Find out more about the ATLAS PhD Grant Scheme: cern.ch/ATLASPhDGrant This programme is just one of the many #CERNandSociety projects at CERN. Find out more and how you can be involved: http://cern.ch/go/pBt7

  4. NEW CLUSTERING SCHEMES FOR WIRELESS SENSOR NETWORKS

    OpenAIRE

    Mazinani, S. M.; J. Chitizadeh; M. H. Yaghmaee; M. T. Honary; F. Tashtarian

    2010-01-01

    In this paper, two clustering algorithms are proposed. In the first one, we investigate a clustering protocol for single hop wireless sensor networks that employs a competitive scheme for cluster head selection. The proposed algorithm is named EECS-M that is a modified version to the well known protocol EECS where some of the nodes become volunteers to be cluster heads with an equal probability.  In the competition phase in contrast to EECS using a fixed competition range for any volunteer no...

  5. Pairing schemes for HFB calculations of nuclei

    CERN Document Server

    Duguet, T; Bonche, P

    2005-01-01

    Several pairing schemes currently used to describe superfluid nuclei through Hartree-Fock-Bogolyubov (HFB) calculations are briefly reviewed. We put a particular emphasis on the regularization recipes used in connection with zero-range forces and on the density dependence which usually complement their definition. Regarding the chosen regularization process, the goal is not only to identify the impact it may or may not have on pairing properties of nuclei through spherical 1D HFB calculations but also to assess its tractability for systematic axial 2D and 3D mean-field and beyond-mean-field calculations.

  6. The Adler Kostant Symes scheme in physics

    OpenAIRE

    Ovando, Gabriela P.

    2008-01-01

    The purpose of this material is to review the Adler Kostant Symes scheme as a theory which can be developped succesfully in different contexts. It was useful to describe some mechanical systems, the so called generalized Toda, and now it was proved to be a tool for the study of the linear approach to the motion of n uncoupled harmonic oscillators. The complete integrability of these systems has an algebraic description. In the original theory this is related to ad-invariant functions, but new...

  7. Pay-what-you-want pricing schemes

    DEFF Research Database (Denmark)

    Kahsay, Goytom Abraha; Samahita, Margaret

    2015-01-01

    Pay-What-You-Want (PWYW) pricing schemes are becoming increasingly popular. We develop a model incorporating self-image into the buyer’s utility function and introduce heterogeneity in consumption utility and image-sensitivity, generating different purchase decisions and optimal prices across...... individuals. When a good’s fixed price is lower than a threshold fair value, PWYW can lead to a lower utility. This may result in a lower purchase rate and higher average price, accounting for previously unexplained field experimental evidence. An increase in the threshold value decreases the buyer’s utility...

  8. A Classification Scheme for Glaciological AVA Responses

    Science.gov (United States)

    Booth, A.; Emir, E.

    2014-12-01

    A classification scheme is proposed for amplitude vs. angle (AVA) responses as an aid to the interpretation of seismic reflectivity in glaciological research campaigns. AVA responses are a powerful tool in characterising the material properties of glacier ice and its substrate. However, before interpreting AVA data, careful true amplitude processing is required to constrain basal reflectivity and compensate amplitude decay mechanisms, including anelastic attenuation and spherical divergence. These fundamental processing steps can be difficult to design in cases of noisy data, e.g. where a target reflection is contaminated by surface wave energy (in the case of shallow glaciers) or by energy reflected from out of the survey plane. AVA methods have equally powerful usage in estimating the fluid fill of potential hydrocarbon reservoirs. However, such applications seldom use true amplitude data and instead consider qualitative AVA responses using a well-defined classification scheme. Such schemes are often defined in terms of the characteristics of best-fit responses to the observed reflectivity, e.g. the intercept (I) and gradient (G) of a linear approximation to the AVA data. The position of the response on a cross-plot of I and G then offers a diagnostic attribute for certain fluid types. We investigate the advantages in glaciology of emulating this practice, and develop a cross-plot based on the 3-term Shuey AVA approximation (using I, G, and a curvature term C). Model AVA curves define a clear lithification trend: AVA responses to stiff (lithified) substrates fall discretely into one quadrant of the cross-plot, with positive I and negative G, whereas those to fluid-rich substrates plot diagonally opposite (in the negative I and positive G quadrant). The remaining quadrants are unoccupied by plausible single-layer responses and may therefore be diagnostic of complex thin-layer reflectivity, and the magnitude and polarity of the C term serves as a further indicator

  9. A Second-Order Unsplit Godunov Scheme for Cell-Centered MHD: the CTU-GLM scheme

    OpenAIRE

    Mignone, A.; Tzeferacos, P.

    2009-01-01

    We assess the validity of a single step Godunov scheme for the solution of the magneto-hydrodynamics equations in more than one dimension. The scheme is second-order accurate and the temporal discretization is based on the dimensionally unsplit Corner Transport Upwind (CTU) method of Colella. The proposed scheme employs a cell-centered representation of the primary fluid variables (including magnetic field) and conserves mass, momentum, magnetic induction and energy. A variant of the scheme, ...

  10. Activities.

    Science.gov (United States)

    Moody, Mally

    1992-01-01

    A series of four activities are presented to enhance students' abilities to appreciate and use trigonometry as a tool in problem solving. Activities cover problems applying the law of sines, the law of cosines, and matching equivalent trigonometric expressions. A teacher's guide, worksheets, and answers are provided. (MDH)

  11. Privacy protection schemes for fingerprint recognition systems

    Science.gov (United States)

    Marasco, Emanuela; Cukic, Bojan

    2015-05-01

    The deployment of fingerprint recognition systems has always raised concerns related to personal privacy. A fingerprint is permanently associated with an individual and, generally, it cannot be reset if compromised in one application. Given that fingerprints are not a secret, potential misuses besides personal recognition represent privacy threats and may lead to public distrust. Privacy mechanisms control access to personal information and limit the likelihood of intrusions. In this paper, image- and feature-level schemes for privacy protection in fingerprint recognition systems are reviewed. Storing only key features of a biometric signature can reduce the likelihood of biometric data being used for unintended purposes. In biometric cryptosystems and biometric-based key release, the biometric component verifies the identity of the user, while the cryptographic key protects the communication channel. Transformation-based approaches only a transformed version of the original biometric signature is stored. Different applications can use different transforms. Matching is performed in the transformed domain which enable the preservation of low error rates. Since such templates do not reveal information about individuals, they are referred to as cancelable templates. A compromised template can be re-issued using a different transform. At image-level, de-identification schemes can remove identifiers disclosed for objectives unrelated to the original purpose, while permitting other authorized uses of personal information. Fingerprint images can be de-identified by, for example, mixing fingerprints or removing gender signature. In both cases, degradation of matching performance is minimized.

  12. A subgrid parameterization scheme for precipitation

    Directory of Open Access Journals (Sweden)

    S. Turner

    2011-07-01

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

  13. Finite-difference schemes for anisotropic diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Es, Bram van, E-mail: es@cwi.nl [Centrum Wiskunde and Informatica, P.O. Box 94079, 1090GB Amsterdam (Netherlands); FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM (Netherlands); Koren, Barry [Eindhoven University of Technology (Netherlands); Blank, Hugo J. de [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM (Netherlands)

    2014-09-01

    In fusion plasmas diffusion tensors are extremely anisotropic due to the high temperature and large magnetic field strength. This causes diffusion, heat conduction, and viscous momentum loss, to effectively be aligned with the magnetic field lines. This alignment leads to different values for the respective diffusive coefficients in the magnetic field direction and in the perpendicular direction, to the extent that heat diffusion coefficients can be up to 10{sup 12} times larger in the parallel direction than in the perpendicular direction. This anisotropy puts stringent requirements on the numerical methods used to approximate the MHD-equations since any misalignment of the grid may cause the perpendicular diffusion to be polluted by the numerical error in approximating the parallel diffusion. Currently the common approach is to apply magnetic field-aligned coordinates, an approach that automatically takes care of the directionality of the diffusive coefficients. This approach runs into problems at x-points and at points where there is magnetic re-connection, since this causes local non-alignment. It is therefore useful to consider numerical schemes that are tolerant to the misalignment of the grid with the magnetic field lines, both to improve existing methods and to help open the possibility of applying regular non-aligned grids. To investigate this, in this paper several discretization schemes are developed and applied to the anisotropic heat diffusion equation on a non-aligned grid.

  14. IMPLEMENTATION OF THE NEW CAREER STRUCTURE SCHEME

    CERN Document Server

    Human Resources Division

    2001-01-01

    CERN's new Merit Advancement and Promotion Scheme, MAPS, comes into force on 1 September, and all members of staff will soon be receiving the official letter of notification of their assimilation into the new scheme. In this announcement, we take a look at where you can learn about the new system. There will also be an article in the Weekly Bulletin at the end of the month, which will summarise the main changes. During the early summer, HR Division presented the new structure to the staff in the Laboratory via Divisional Information Meetings. The transparencies used in these meetings, along with a list of the most relevant questions and answers, a Career Path Guide as well as a general overview document are available on the HR Division web site http://cern.ch/CERN/Divisions/PE/. Hard copies of the latter document are also available from the Divisional secretariats. The first question most staff members will ask is how they will fit into the new career path structure. Via the same web page, they can type in th...

  15. A subgrid parameterization scheme for precipitation

    Directory of Open Access Journals (Sweden)

    S. Turner

    2012-04-01

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

  16. Information field dynamics for simulation scheme construction

    CERN Document Server

    Enßlin, Torsten A

    2012-01-01

    Information field dynamics (IFD) is introduced here as a framework to derive numerical schemes for the simulation of physical and other fields. Any simulation scheme updates a discretized field representation, the data in a computer's memory, for the next time step according to a discretized, approximate representation of the underlying field dynamics. Assumptions about the continuum field behavior on sub-grid scales are reflected in these rules, e.g. the field might be assumed to be constant within a grid cell, or to be some weighted average of neighboring data points, and the like. In contrast to such parametrized sub-grid field structures, IFD constructs non-parametric sub-grid field configurations from the combination of the data, representing constraints on possible field configurations, and prior assumptions on the sub-grid field statistics. Each of these field configurations can formally be evolved to a later moment since any differential operator of the dynamics can act on fields living in continuous ...

  17. Password Authentication Based on Fractal Coding Scheme

    Directory of Open Access Journals (Sweden)

    Nadia M. G. Al-Saidi

    2012-01-01

    Full Text Available Password authentication is a mechanism used to authenticate user identity over insecure communication channel. In this paper, a new method to improve the security of password authentication is proposed. It is based on the compression capability of the fractal image coding to provide an authorized user a secure access to registration and login process. In the proposed scheme, a hashed password string is generated and encrypted to be captured together with the user identity using text to image mechanisms. The advantage of fractal image coding is to be used to securely send the compressed image data through a nonsecured communication channel to the server. The verification of client information with the database system is achieved in the server to authenticate the legal user. The encrypted hashed password in the decoded fractal image is recognized using optical character recognition. The authentication process is performed after a successful verification of the client identity by comparing the decrypted hashed password with those which was stored in the database system. The system is analyzed and discussed from the attacker’s viewpoint. A security comparison is performed to show that the proposed scheme provides an essential security requirement, while their efficiency makes it easier to be applied alone or in hybrid with other security methods. Computer simulation and statistical analysis are presented.

  18. Multiplexing schemes for quantum repeater networks

    Science.gov (United States)

    Aparicio, Luciano; Van Meter, Rodney

    2011-08-01

    When built, quantum repeaters will allow the distribution of entangled quantum states across large distances, playing a vital part in many proposed quantum technologies. Enabling multiple users to connect through the same network will be key to their real-world deployment. Previous work on repeater technologies has focussed only on simple entanglment production, without considering the issues of resource scarcity and competition that necessarily arise in a network setting. In this paper we simulated a thirteen-node network with up to five flows sharing different parts of the network, measuring the total throughput and fairness for each case. Our results suggest that the Internet-like approach of statistical multiplexing use of a congested link gives the highest aggregate throughput. Time division multiplexing and buffer space multiplexing were slightly less effective, but all three schemes allow the sum of multiple flows to substantially exceed that of any one flow, improving over circuit switching by taking advantage of resources that are forced to remain idle in circuit switching. All three schemes proved to have excellent fairness. The high performance, fairness and simplicity of implementation support a recommendation of statistical multiplexing for shared quantum repeater networks.

  19. Novel copyright protection scheme for digital content

    Institute of Scientific and Technical Information of China (English)

    Fan Kefeng; Wang Meihua; Mo Wei; Zhao Xinhua

    2006-01-01

    A novel copyright protection scheme for digital content is presented, which is a private watermarking scheme based on the watermark embedding in the DCT domain and watermark extraction using independent component analysis (ICA). The system includes the key for watermark extraction and the host image. The algorithm splits the original image into blocks and classifies these blocks based on visual masking, that is, noise visibility function (NVF). Watermark components with different strength are inserted into chosen direct current components of DCT coefficients according to the classifier. The watermark extraction is based on the characteristic of the statistic independence of the host image, watermark and key. Principle component analysis (PCA) whitening process and FastICA techniques are introduced to ensure a blind watermark extraction without requiring the original image. Experimental results show the proposed technique is robust under attacks such as image filtering and adding noise, cropping and resizing. In addition, the proposed private watermarking system can be improved to the application of the DTV content protection system.

  20. Pricing Schemes in Cloud Computing: An Overview

    Directory of Open Access Journals (Sweden)

    Artan Mazrekaj

    2016-02-01

    Full Text Available Cloud Computing is one of the technologies with rapid development in recent years where there is increasing interest in industry and academia. This technology enables many services and resources for end users. With the rise of cloud services number of companies that offer various services in cloud infrastructure is increased, thus creating a competition on prices in the global market. Cloud Computing providers offer more services to their clients ranging from infrastructure as a service (IaaS, platform as a service (PaaS, software as a service (SaaS, storage as a service (STaaS, security as a service (SECaaS, test environment as a service (TEaaS. The purpose of providers is to maximize revenue by their price schemes, while the main goal of customers is to have quality of services (QoS for a reasonable price. The purpose of this paper is to compare and discuss several models and pricing schemes from different Cloud Computing providers.