The Experts below are selected from a list of 370935 Experts worldwide ranked by ideXlab platform
Byunggook Park - One of the best experts on this subject based on the ideXlab platform.
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electron trap density distribution of si rich silicon nitride extracted using the modified negative charge Decay Model of silicon oxide nitride oxide silicon structure at elevated temperatures
Applied Physics Letters, 2006Co-Authors: I H Park, Hyungcheol Shin, Byunggook ParkAbstract:The authors modified the charge Decay Model of silicon-oxide-nitride-oxide-silicon-type memory at the temperatures above 150°C. The modified Model includes the effect of the internal electric field induced by the charges trapped in silicon nitride layer. The authors extracted the trap density distributions in energy level of the Si-rich silicon nitride using the Model and compared them with those of stoichiometric silicon nitride. It has been revealed that the Si-rich silicon nitride has larger trap density in shallow energy level than the stoichiometric silicon nitride and this relation is reversed as the energy level goes deeper.
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charge Decay characteristics of silicon oxide nitride oxide silicon structure at elevated temperatures and extraction of the nitride trap density distribution
Applied Physics Letters, 2004Co-Authors: Hyungcheol Shin, Byunggook ParkAbstract:We investigated the charge Decay characteristics of a silicon-oxide-nitride-oxide-silicon type nonvolatile memory at elevated temperatures. Based on the amphoteric trap Model and the thermal emission Model of the trapped charge, we propose an advanced charge Decay Model which includes the effect of the bottom oxide, and apply it to extraction of the trap density distribution in energy levels of the nitride layer. The samples prepared have nitride films deposited simultaneously and are classified into two groups according to the thickness of the bottom oxide. The trap density distributions extracted from two groups showed good consistency.
Hyungcheol Shin - One of the best experts on this subject based on the ideXlab platform.
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electron trap density distribution of si rich silicon nitride extracted using the modified negative charge Decay Model of silicon oxide nitride oxide silicon structure at elevated temperatures
Applied Physics Letters, 2006Co-Authors: I H Park, Hyungcheol Shin, Byunggook ParkAbstract:The authors modified the charge Decay Model of silicon-oxide-nitride-oxide-silicon-type memory at the temperatures above 150°C. The modified Model includes the effect of the internal electric field induced by the charges trapped in silicon nitride layer. The authors extracted the trap density distributions in energy level of the Si-rich silicon nitride using the Model and compared them with those of stoichiometric silicon nitride. It has been revealed that the Si-rich silicon nitride has larger trap density in shallow energy level than the stoichiometric silicon nitride and this relation is reversed as the energy level goes deeper.
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charge Decay characteristics of silicon oxide nitride oxide silicon structure at elevated temperatures and extraction of the nitride trap density distribution
Applied Physics Letters, 2004Co-Authors: Hyungcheol Shin, Byunggook ParkAbstract:We investigated the charge Decay characteristics of a silicon-oxide-nitride-oxide-silicon type nonvolatile memory at elevated temperatures. Based on the amphoteric trap Model and the thermal emission Model of the trapped charge, we propose an advanced charge Decay Model which includes the effect of the bottom oxide, and apply it to extraction of the trap density distribution in energy levels of the nitride layer. The samples prepared have nitride films deposited simultaneously and are classified into two groups according to the thickness of the bottom oxide. The trap density distributions extracted from two groups showed good consistency.
I H Park - One of the best experts on this subject based on the ideXlab platform.
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electron trap density distribution of si rich silicon nitride extracted using the modified negative charge Decay Model of silicon oxide nitride oxide silicon structure at elevated temperatures
Applied Physics Letters, 2006Co-Authors: I H Park, Hyungcheol Shin, Byunggook ParkAbstract:The authors modified the charge Decay Model of silicon-oxide-nitride-oxide-silicon-type memory at the temperatures above 150°C. The modified Model includes the effect of the internal electric field induced by the charges trapped in silicon nitride layer. The authors extracted the trap density distributions in energy level of the Si-rich silicon nitride using the Model and compared them with those of stoichiometric silicon nitride. It has been revealed that the Si-rich silicon nitride has larger trap density in shallow energy level than the stoichiometric silicon nitride and this relation is reversed as the energy level goes deeper.
Frank Holzapfel - One of the best experts on this subject based on the ideXlab platform.
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skill of an aircraft wake vortex transport and Decay Model using short term weather prediction and observation
2006Co-Authors: Michael Frech, Frank HolzapfelAbstract:In order to safely reduce aircraft separation during approach and landing, the wake vortex behavior along the glide path has to be known and predicted. This requires in principle the knowledge of wake vortex relevant meteorological parameters along the entire glide path where typically continuous meteorological measurements of all relevant variables are not feasible. For multiple purposes a one-year meteorological data base for the Frankfurt Terminal area has been generated using NOWVIV. The skill of the nowcasting system NOWVIV (Nowcasting Wake Vortex Impact Variables) to predict these environmental parameters is assessed. This one-year data set comprises typical weather conditions and includes already typical features of a long-term surface wind climatology. It enables to test new operational concepts with realistic meteorological input and to estimate the potential for aircraft separation reduction. It may also be used within risk assessments for prototype wake-vortex advisory systems. A subset of the one-year data base is analysed in detail for a period of 40 days where a dedicated wake measurement campaign was carried out at Frankfurt airport in fall 2004. In total 231 wake vortex pairs generated by heavy aircraft in ground proximity were tracked and characterized by LIDAR. During this measurement campaign a SODAR/RASS and a LIDAR provided profile measurements of meteorological variables. These data are used to analyse the quality of the predicted profiles of wind, temperature and turbulence. Furthermore we carry out a skill analysis to investigate the potential of NOWVIV as a real-time prediction system where we focus on the ability to predict pre-defined cross wind thresholds. The skill of NOWVIV is compared to the skill of a simple cross wind persistence Model based on SODAR measurements. For this purpose we assume that a given measured cross wind profile is valid over the whole forecast lead time and evaluate the skill of the forecast with increasing lead time every 10 minutes. In a wake-vortex advisory system, the weather prediction and observation system is coupled to a wake vortex predictor. Therefore, we have to know how the predictive skill of the weather forcast system influences the predictive skill of the whole forecast system chain including the wake predictor. Consequently, we extend this analysis by coupling the Probabilistic Two-Phase wake vortex transport and Decay Model P2P to the NOWVIV system and investigate the predictive skill of P2P for pre-selected confidence levels of vortex position and strength. The skill is assessed by comparing the predictions against LIDAR measured wake vortex position and strength. Initially, the overall skill of the wake vortex forecast is analysed. We then analyse the skill of the Models with respect to observed and predicted clearance of a safety corridor from wake vortices (WV). In particular, we focus on the frequency of non-conservative predictions, which refer to a situation where a wake vortex is predicted to be outside a predefined safety corridor while observations still indicate the presence of a wake vortex in the safety corridor. A non-conservative predictions refers to a potential risk for a following aircraft which has to be avoided.
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probabilistic two phase aircraft wake vortex Model application and assessment
Journal of Aircraft, 2004Co-Authors: Frank Holzapfel, Robert E RobinsAbstract:Predictions of the parametric probabilistic two-phase aircraft wake-vortex transport and Decay Model P2P are compared with field observations. The two-phase Decay Model predicts probabilistic wake-vortex behavior as a function of aircraft and environmental parameters in real time. Observation data from field deployments accomplished at the International Airports Memphis and Dallas Fort Worth and from the WakeOP campaign performed at the airfield in Oberpfaffenhofen, Germany, are employed. In a scoring procedure, the predictive capabilities of a deterministic version of P2P are compared to Sarpkaya's Model
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probabilistic two phase wake vortex Decay and transport Model
Journal of Aircraft, 2003Co-Authors: Frank HolzapfelAbstract:A new parametric wake vortex transport and Decay Model is proposed that predicts probabilistic wake vortex behavior as a function of aircraft and environmental parameters in real time. The probabilistic two-phase wake vortex Decay Model (P2P) accounts for the effects of wind, turbulence, stable stratification, and ground proximity. The Model equations are derived from the analytical solution of the spatiotemporal circulation evolution of the Decaying potential vortex and are adapted to wake vortex behavior as observed in large-eddy simulations. Vortex Decay progresses in two phases, a diffusion phase followed by rapid Decay. Vortex descent is a nonlinear function of vortex strength. Probabilistic components account for deviations from deterministic vortex behavior inherently caused by the stochastic nature of turbulence, vortex instabilities, and deformations, as well as uncertainties and fluctuations that arise from environmental and aircraft parameters. The output of P2P consists of confidence intervals for vortex position and strength
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probabilistic two phase wake vortex Decay and transport Model
Journal of Aircraft, 2003Co-Authors: Frank HolzapfelAbstract:A new parametric wake vortex transport and Decay Model is proposed that predicts probabilistic wake vortex behavior as a function of aircraft and environmental parameters in real time. The probabilistic two-phase wake vortex Decay Model (P2P) accounts for the effects of wind, turbulence, stable stratie cation, and ground proximity. The Model equations are derived from the analytical solution of the spatiotemporal circulation evolution of the Decaying potential vortex and are adapted to wake vortex behavior as observed in large-eddy simulations. Vortex Decay progresses in two phases, a diffusion phase followed by rapid Decay. Vortex descent is a nonlinear function of vortex strength. Probabilistic components account for deviations from deterministic vortex behavior inherently caused by the stochastic nature of turbulence, vortex instabilities, and deformations, as well as uncertainties and e uctuations that arise from environmental and aircraft parameters. The output of P2P consists of cone dence intervals for vortex position and strength. To assign a dee ned degree of probability to the predictions reliably, the Model design allows for the continuous adjustment of Decay parameters and uncertainty allowances, based on a growing amount of data. The application of a deterministic version of P2P to the Memphis wake vortex database yields favorable agreement with measurements.
Ran Zhang - One of the best experts on this subject based on the ideXlab platform.
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nonclassical thermal state superpositions analytical evolution law and decoherence behavior
Optics Communications, 2018Co-Authors: Xiangguo Meng, Jisuo Wang, Hsi-sheng Goan, Ran ZhangAbstract:Abstract Employing the integration technique within normal products of bosonic operators, we present normal product representations of thermal-state superpositions and investigate their nonclassical features, such as quadrature squeezing, sub-Poissonian distribution, and partial negativity of the Wigner function. We also analytically and numerically investigate their evolution law and decoherence characteristics in an amplitude-Decay Model via the variations of the probability distributions and the negative volumes of Wigner functions in phase space. The results indicate that the evolution formulas of two thermal component states for amplitude Decay can be viewed as the same integral form as a displaced thermal state ρ ( V , d ) , but governed by the combined action of photon loss and thermal noise. In addition, the larger values of the displacement d and noise V lead to faster decoherence for thermal-state superpositions.
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nonclassical thermal state superpositions analytical evolution law and decoherence behavior
Optics Communications, 2018Co-Authors: Xiangguo Meng, Jisuo Wang, Hsi-sheng Goan, Ran ZhangAbstract:Abstract Employing the integration technique within normal products of bosonic operators, we present normal product representations of thermal-state superpositions and investigate their nonclassical features, such as quadrature squeezing, sub-Poissonian distribution, and partial negativity of the Wigner function. We also analytically and numerically investigate their evolution law and decoherence characteristics in an amplitude-Decay Model via the variations of the probability distributions and the negative volumes of Wigner functions in phase space. The results indicate that the evolution formulas of two thermal component states for amplitude Decay can be viewed as the same integral form as a displaced thermal state ρ ( V , d ) , but governed by the combined action of photon loss and thermal noise. In addition, the larger values of the displacement d and noise V lead to faster decoherence for thermal-state superpositions.
