Underflow Conditions Research Articles

Modeling and Simulation of Phase Change Memory Using Digital Logic Implementation Approach

Phase Change Memory (PCM) adapts to space utilization and bit storage for displaying amorphous or crystalline states. This change of state relies on the nature of the information and its non-volatility period. As is well known Digital Logic operations are influential over memory modeling, this article introduces a Propagative Adaptability Decision Module (PADM) using DL. This module is utilized based on the information non-volatility across overflow and underflow memory conditions. This utilization-based classification induces the digital logic influence by swapping the states that are robust for further propagative adaptability. This means the possible logical combinations of 0’s and 1’s are used for deciding the states of PCM. The logical operations using OR and NOT are used for reducing overflows whereas the AND and NOT combinations are used for preventing underflows. This reduces the volatility show-up in two distinct phases of memory utilization. Therefore, the 0 and 1 combinations are validated for all the logical operations to ensure propagative memory swapping for balancing the overflow and underflow conditions. This process does not mark up the highest 1 or 0 combination individually due to state changes. The proposed module is validated using swapping rate, time, complexity, and overflow conditions.

Pixel Value Ordering Based Reversible Data Hiding with Novel MPBS Strategy

Recently, Reversible Data Hiding (RDH) techniques has gained much attention in many sensitive fields such as remote sensing, archive management, military and medical image processing systems. This is due to the lossless data extraction ability of RDH schemes. The primary goal of RDH schemes is to achieve high embedding rates while maintaining the quality of cover objects. For achieving better performance, Pixel Value Ordering (PVO) based reversible data hiding schemes have been proposed. PVO refers to the process of ranking the pixels in blocks and then modifying the pixels according to some embedding rules/conditions. So far, the existing PVO techniques have considered neighborhood pixels at unit distance. In this paper, an improved RDH using block based PVO scheme is proposed which exploits the pixel correlation efficiently by increasing the block size and applying a novel Median Pixel based Block Selection Strategy (MPBS). When block size is increased, the ordering of pixels is changed after embedding. So, to extract the secret data in a lossless manner, the secret bits are swapped in accordance with their corresponding Stego pixels’ index order. Also, the overflow and underflow conditions are effectively handled using Location Map. Experimental results show the better performance of the proposed RDH technique with the existing technique.

Meta-Heuristics Based Load Balancing Optimization in Cloud Environment on Underflow and Overflow Conditions

In cloud environment, the main challenge is load balancing as it requires distributing the load among many various virtual machines (VM) while avoiding underflow and overflow conditions. In this article, the question that which load-balancing (overflow or underflow) management will better improves the performance and quality of service has been answered with a number of experiments. For experiment purpose, scientific workflow DAG files has been used with one host configuration. Ant Colony Optimization (ACO) and BAT algorithm are used for checking underflow and overflow conditions respectively for VMs. In proposed work, initially the workflow is parsed by Predict Earliest Finish Time (PEFT) heuristic to generate initial seed for meta-heuristic algorithms which will optimize the VM in terms of makespan and cost of execution. Different workflows have been used with varying number of VMs from 2 to 20. The results shows that makespan analysis is approximately overlapped for different workflow tasks and shows no significant difference however, the cost analysis show a significant change for overflow and underflow identification with cost for overflow condition is reduced significantly.

Increased Platelet Thrombus Formation Under Flow Condition In Myeloproliferative Neoplasms (MPN)

BackgroundEssential Thrombocythemia (ET) and Polycythemia Vera (PV) are MPNs characterized by a high incidence of both arterial and venous thrombosis, and microcirculatory disturbances. Platelet abnormalities have been variably involved in the thrombotic diathesis of these patients, without providing conclusive evidence. Remarkably, no studies have explored so far the MPN platelet thrombus formation capacity underflow conditions. AimIn order to evaluate whether and to what extent the MPN platelet membrane abnormalities may influence their interactions with the vessel wall components in a dynamic system, we wanted to characterize the ET and PV platelet adhesion capacity under flow conditions, by using an in vitro system based on a parallel flow chamber connected to the EVOS fluorescence microscope. The effects of the V617F JAK2 mutational status, cytoreductive therapy, and circulating von Willebrand Factor (vWF) on platelet adhesion in this system were also explored. MethodsNine ET (3M/6F; age 63 years, range 60-81) and 6 PV (3M/4F; age 74 years, range 58-82) patients were enrolled into the study upon informed consent. Eleven healthy subjects (5M/6F; age 44 years, range 35-55) acted as a control group (CTR). Peripheral venous whole blood was withdrawn in sodium citrate, recalcified in the presence of heparin, and perfused over a collagen-coated surface for 4 min at a shear rate of 1000 s-1. Platelets were then stained with an anti-CD62P (P-selectin)-FITC antibody as a platelet activation index, and annexin V-AlexaFluor647 as a measure of the procoagulant phosphatidylserine (PS) expression. After staining, images of adherent platelets in random fields were taken using phase contrast and fluorescence imaging with the EVOS fluorescence microscope system. Results were the mean±SD of the percentage of area covered by all platelets, or as the % of adherent platelets positive to either P-selectin or annexin V. In parallel, plasma vWF antigen and activity levels were measured by ELISA. Statistical analysis was performed by SPSS software package. ResultsPlatelet adhesion was significantly greater (p<0.05) in both ET (49.3±14.5%) and PV patients (55.3±12.7%) compared to controls (31.6±7.3%). Among patients, platelet adhesion was significantly (p<0.05) increased in those positive for the V617F JAK2 mutation compared to the negative ones, with the highest values in the homozygous subjects. Patients on hydroxyurea (HU) therapy (n=7) had significantly lower platelet adhesion (45.2±13.0%) compared to non-HU-treated patients (56.9±10.4%; p<0.05).The % platelet adhesion directly related to either platelet (r=0.623, p=0.001) and leukocyte (r=0.506, p<0.01) counts, but not to plasma vWF levels. Multivariate regression analysis adjusted for age, sex, and HU therapy, confirmed platelet count and V617F JAK2 mutation as significant determinants of platelet adhesion. Although adhesion was increased, the platelet surface expression of P-selectin and PS was reduced in ET (P-sel: 70±11% pos. platelets; PS: 11±6% pos. platelets) and PV (P-sel: 66±13%; PS: 9±5%) patients compared to controls (P-sel: 74±8%; PS: 20±8%). ConclusionsThe data show for the first time, in MPN patients, an increased platelet adhesion capacity to collagen under flow conditions, indicating a greater thrombus formation potential. This phenomenon is likely not related to the expression of membrane P-selectin and phosphatidylserine, but is significantly influenced by the V617F JAK2 mutation burden and is sensitive to the cytoreductive treatment with HU. Prospective studies are worth to establish the role of the EVOS assay in assessing the levels of thrombotic risk in MPN patients. Disclosures:No relevant conflicts of interest to declare.

Connections between River Runoff and Limnological Conditions in Adjacent High Arctic Lakes: Cape Bounty, Melville Island, Nunavut

Hydrological and hydrochemical monitoring of paired watersheds in the High Arctic was conducted in 2003–04 to investigate the influence of seasonal runoff on lake water chemistry and productivity. Despite similar limnological conditions overall between the two lakes, marked differences in aquatic productivity were attributed to watershed and basin morphology and the resultant influences on lake ice deterioration and growing season length. A switch from allochthonous to autochthonous sources of carbon late in the season reflected the simultaneous decline in river runoff and increase in aquatic productivity as the growing season progressed. However, low air temperatures and protracted snowmelt and ponding in the deeply incised channel of one river in 2003 led to greater solute accumulation in runoff that was discernable in hydrochemical profiles of that lake, even though runoff was greater in 2004. Notwithstanding, calculated nutrient fluxes were greater during the higher-flow year (2004), but mixing was impeded by underflow conditions in the lakes. Despite these differences, connections between river and lake water chemistry appeared weak even with marked seasonal changes in the volume of runoff. Our results highlight the interconnection between site-specific features and hydroclimatic factors like snowmelt and lake ice conditions in influencing limnological conditions and suggest that similar systems may respond differently to the same hydroclimatic conditions.

Density-based separation in a vibrated Reflux Classifier with an air-sand dense-medium: Tracer studies with simultaneous underflow and overflow removal

The continuous separation of tracer particles in the air-sand dense-medium Reflux Classifier was investigated. The Reflux Classifier consisted of a 1 m long vertical fluidized bed section with a 2 m long channel inclined at 70° to the horizontal mounted above, both with a 20 × 100 mm cross section. Silica sand of 220 μm average diameter (−355 + 125 μm) was used as the dense medium. The Reflux Classifier produced good density separations for tracer particles ranging in size from 6.35 down to 1.0 mm. The density cut-point could be varied from 1418 to 2130 kg/m 3 by varying the underflow rate and the Ep was within the range of 0.06–0.46 × 10 3 kg/m 3 depending on particle size and gas rate. At certain gas flowrate and underflow conditions the density cut point ranged between 1534 and 1619 kg/m 3 across six particle sizes, suppressing the effects of particle size on the density cut point. As air rates increased from 4.03 to 5.64 × 10 −4 m 3/s the density cut-point increased, as did the Ep. The results were compared with separations in a vertical fluidized bed of the same total length. Ep values in the vertical fluidized bed ranged between 0.07 and 1.49 × 10 3 kg/m 3 over the same experimental conditions as the inclined bed and the density cut point showed more variability with the conditions. The addition of an incline above the fluidized bed provides a more stable system allowing for greater separation efficiency and minimizing the effect of changing conditions. Increasing the flow of sand medium to the underflow decreased the density cut point while raising the gas rate increased the density cut point. Raising the gas rate also increased the variability of the system which resulted in a lower separation efficiency.

Method and apparatus for compensating reproduced audio signals of an optical disk

An apparatus and method for compensating audio signals to be recorded on an optical disc to optimize usage of memory in an audio decoding circuit, and to neutralize invalid audio data to produce good audio quality. A determination is made with regard to whether audio data signals contain normal data or invalid data. Invalid data is adjusted into normal audio data, and stored in the memory. The volume of the data stored in the memory is monitored to detect overflow and underflow conditions of the memory, a data transmitting stopping signal being sent during an overflow condition of the memory, a data transmitting requesting signal being sent during an underflow condition. The audio data reproduced from the memory is decoded, and the decoded audio data is output. Undesired errors are prevented by monitoring the reproduced audio data for invalid data and by adjusting invalid data into normal data when detected.

On the Rio Grande Aquifer: Flow Relationships, Salinization, and Environmental Problems From El Paso to Fort Quitman, Texas

The Rio Grande floodplain between the City of El Paso and Fort Quitman, Texas (70 mi [113 km] reach) varies from intensively urbanized (first 20 mi [32 km]), to intensively irrigated by surface and ground water (next 40 mi [65 km]), to sparsely inhabited and little developed (last 10 mi [16 km]). Water-level contour maps prepared with recent and historical data illustrate losing stream, underflow, and baseflow conditions on different segments of the alluvial floodplain. The condition of losing stream is apparent along the urbanized zone where draw-down cones from municipal well fields have reversed the hydraulic gradient between the river and the Rio Grande aquifer. Aquifer flow varies from underflow to gaining stream downstream from the urbanized zone. Hydrochemistry of the Rio Grande aquifer evolves downstream from a Na-Ca-mixed anion type water with TDS mostly between 1,000 and 3,500 mg/L to a Na-Ca-SO 4 -Cl type water with TDS mostly between 3,000 to 6,000 mg/L. Plots of 2 H vs 18 O for ground-water samples collected in the Mexican part of the Rio Grande aquifer follow an evaporation trend. The most enriched samples correspond to higher salinity and greater distances downstream. Monthly water-quality data from the Rio Grande show similar changes in hydrochemistry. Increasing salinity in both the Rio Grande and Rio Grande aquifer generally reflect the tendency for salts to be recycled in irrigation water, to return to the Rio Grande, and then to be reapplied to crops. By this process the salinities in the Rio Grande and Rio Grande aquifer increase in a continuous manner downstream. Other existing and potential water-quality problems in the Rio Grande and Rio Grande aquifer include fecal coliform bacteria, nitrate, pesticides, and organic contaminants. These are a concern because of cross-formational flow between the Rio Grande aquifer and the Hueco Bolson aquifer, the latter a source of water for more than 1.6 million residents along the El Paso/Ciudad Juarez corridor.

EFFECT OF PARTICLE CONCENTRATION ON TURBULENCE CHARACTERISTICS OF 2-D SOLID-LIQUID TWO-PHASE JET FLOW

A laboratory experiment of solid-liquid two phase flow in a vertical two-dimensional jet, as oneof typical multiphase turbulent flows, has been conducted for extending the applicability of the newmultiphase LES (GAL-LES model), which has been recently developed by the authors. The effect ofthe particle concentration on the turbulence characteristics of the two-phase flow is investigated underflow conditions with the two different particle flow rate at the inlet slot. The turbulence intensity of theliquid velocity was found to increase with the particle discharge. The particle-discharge dependence was found also on the lateral distribution of turbulence intensity and the frequency spectra of liquid turbulence, indicating the importance of the relative contribution to turbulence energy production fromthe Reynolds stress and the wakes behind particles.

713-5 Nω-nitro-L-arginine Methyl Ester Increases Mural Platelet Deposition and Neutrophil-endothelial Interactions Under Low and High Shear Conditions

Whether infusion of a nitric oxide (NO) synthesis inhibitor, N ω -nitro-L-arginine methyl ester (L-NAME), can modulate mural platelet deposition and neutrophil interaction with the endothelium underflow conditions was examined in ex vivo bioassay experiments. Porcine aortic media, simulating deep arterial wall injury, or porcine aortic endothelium was exposed to flowing arterial blood from L-NAME-treated pigs for 5 min at 37°C under low (424 sec -1 ) and high (3397 sec -l ) shear conditions in superfusion flow chambers. Intravenous administration of L-NAME (3 mg/kg bolus + 3 mg/kg/h perfusion) increased systolic (from 82.2 ± 2.7 to 108.5 ± 3.8 mmHg; p &lt; 0.001). diastolic (from 47.4 ± 2.1 to 76.6 ±;3.6 mmHg; p &lt; 0.001) and mean (from 59.0 ± 2.2 to 87.2 ± 3.6 mmHg; p &lt; 0.001) arterial blood pressures with a slight reduction in heart rate (from 155 ± 8 to 139 ± 7 beats/min: p &lt; 0.01). 51 Cr platelet deposition on aortic media exposed to low and high shear rates was increased, respectively, from 15.9 ± 2.9 to 20.4 ± 2.8 x 10 6 /cm 2 (p &lt; 0.05) and from 71.4 ± 11.9 to 95.8 ± 12.5 × 10 6 /cm 2 (p &lt; 0.02) following LNAME treatment. 111 In neutrophil adhesion to intact endothelium was also enhanced by L-NAME from 9.8 ± 2.4 to 18.3 ± 5.2 x 10 3 / cm 2 (p &lt; 0.03) and from 12.5 ± 4.1 to 29.1 ± 8.8 x 103/cm 2 (p &lt; 0.02) under respectively low and high shear rates. However, platelet interaction with the endothelium remained low and the endothelium maintained its thromboresistance. Administration of the specific inhibitor of NO synthesis LNAME increased arterial blood pressure and enhanced platelet interaction with the injured vessel wall and neutrophil adhesion to thromboresistant endothelium under low and high shear conditions.

An accurate computation of the hypergeometric distribution function

The computation of the cumulative hypergeometric distribution function is of interest to many researchers who are working in the computational sciences and related areas. Presented here is a new method for computing this function that applies prime number factorization to the factorials. We also apply cancellation to the numerator and denominator to reduce the computational complexity of the initial, the tail end, or weighted probabilities to achieve maximum accuracy. The new method includes two algorithms, one using recursion and the other using iteration. These two algorithms are machine independent; precision is arbitrary, subject to storage limitation. The development of the algorithms is discussed, and some test results and the comparison of these two algorithms are given. To implement both algorithms, we use the Ada programming language that is an American National Standard Institute standardized language. The language has special features such as exception handling and tasks . Exception handling is used to make programming easier and to prevent overflow or underflow conditions during the execution of the program. Tasks are used to compute the numerator and denominator concurrently, and to maximize the possible number of integer multiplications in the numerator and denominator. All of the computations can be done on currently available machines, and the time consumed by these computations remains reasonably small.

Exponential and Logarithm by Sequential Squaring

A simple scheme is presented for computing the exponential of a floating point number using only shift, add, and multiply instructions. The algorithm involves no range reduction and handles overflow and underflow conditions automatically. It can be used to provide a result of any desired accuracy, provided only that sufficient precision is used during the calculation. The basic algorithm and three improvements are described. Both computational complexity and numerical precision are discussed. For the sake of symmetry, a method for computing the logarithm along similar lines is given.