scholarly journals Optimization of the PNG Law for a Dual-Spin Mortar with Fixed Canards

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Pengfei Liu ◽  
Hongsong Cao ◽  
Shunshan Feng ◽  
Hengzhu Liu ◽  
Lifei Cao
Keyword(s):  
Empirical Method ◽  
Impact Point ◽  
Gravity Compensation ◽  
Proportional Navigation ◽  
Squared Error ◽  
Intelligent Optimization Algorithm ◽  
The Mean ◽  
Optimization Schemes ◽  
The Impact ◽  
Selection Of

The limited instantaneous overload available and the curved trajectory lead to adaptivity problems for the proportional navigation guidance (PNG) of a guided mortar with a fixed-canard trajectory correction fuze. In this paper, the optimization of a PNG law with gravity compensation is established. Instead of using the traditional empirical method, the selection of the proportional navigation constants is formulated as an optimization problem, which is solved using an intelligent optimization algorithm. Two optimization schemes are proposed for constructing corresponding optimization models. In schemes 1 and 2, the sum squared error between the impact point and target and the circular error probability (CEP), respectively, are taken as the objective function. Monte Carlo simulations are conducted to verify the effectiveness of the two optimization schemes, and their guidance performance is compared through trajectory simulations. The simulation results show that the impact point dispersion can be efficiently reduced under both proposed schemes. Scheme 2 achieves a lower CEP, which is approximately 2.9 m and 2.4 times smaller than that achieved by scheme 1. Moreover, the mean impact point is closer to the target.

scholarly journals Including operational data in QMRA model: development and impact of model inputs

2008 ◽  
Vol 7 (1) ◽  
pp. 77-95 ◽  
Author(s):  
Kenza Jaidi ◽  
Benoit Barbeau ◽  
Annie Carrière ◽  
Raymond Desjardins ◽  
Michèle Prévost
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Model ◽  
Model Development ◽  
Microbial Risk ◽  
Relative Risks ◽  
The Mean ◽  
Log Normal ◽  
Simplified Calculation ◽  
The Impact ◽  
Selection Of

A Monte Carlo model, based on the Quantitative Microbial Risk Analysis approach (QMRA), has been developed to assess the relative risks of infection associated with the presence of Cryptosporidium and Giardia in drinking water. The impact of various approaches for modelling the initial parameters of the model on the final risk assessments is evaluated. The Monte Carlo simulations that we performed showed that the occurrence of parasites in raw water was best described by a mixed distribution: log-Normal for concentrations > detection limit (DL), and a uniform distribution for concentrations < DL. The selection of process performance distributions for modelling the performance of treatment (filtration and ozonation) influences the estimated risks significantly. The mean annual risks for conventional treatment are: 1.97E−03 (removal credit adjusted by log parasite = log spores), 1.58E−05 (log parasite = 1.7 × log spores) or 9.33E−03 (regulatory credits based on the turbidity measurement in filtered water). Using full scale validated SCADA data, the simplified calculation of CT performed at the plant was shown to largely underestimate the risk relative to a more detailed CT calculation, which takes into consideration the downtime and system failure events identified at the plant (1.46E−03 vs. 3.93E−02 for the mean risk).

scholarly journals High-end climate change impact on European water availability and stress: exploring the presence of biases

2015 ◽  
Vol 12 (7) ◽  
pp. 7267-7325 ◽  
Author(s):  
L. V. Papadimitriou ◽  
A. G. Koutroulis ◽  
M. G. Grillakis ◽  
I. K. Tsanis
Keyword(s):  
Global Warming ◽  
Bias Correction ◽  
Climate Models ◽  
Climate Model ◽  
Water Cycle ◽  
Order Of Magnitude ◽  
Change Impact ◽  
The Mean ◽  
The Impact ◽  
Selection Of

Abstract. Climate models project a much more substantial warming than the 2 °C target making higher end scenarios increasingly plausible. Freshwater availability under such conditions is a key issue of concern. In this study, an ensemble of Euro-CORDEX projections under RCP8.5 is used to assess the mean and low hydrological states under +4 °C of global warming for the European region. Five major European catchments were analyzed in terms of future drought climatology and the impact of +2 vs. +4 °C global warming was investigated. The effect of bias correction of the climate model outputs and the observations used for this adjustment was also quantified. Projections indicate an intensification of the water cycle at higher levels of warming. Even for areas where the average state may not considerably be affected, low flows are expected to reduce leading to changes in the number of dry days and thus drought climatology. The identified increasing or decreasing runoff trends are substantially intensified when moving from the +2 to the +4 °C of global warming. Bias correction resulted in an improved representation of the historical hydrology. It is also found that the selection of the observational dataset for the application of the bias correction has an impact on the projected signal that could be of the same order of magnitude to the selection of the RCM.

Abstract TP322: The Selection of Enteral Nutrition in Stroke Influence on In-Hospital Infection Control and Hospital Cost

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Hidetaka Onodera ◽  
Takuma Mogamiya ◽  
Shinya Matsushima ◽  
Kimiyuki Kawaguchi ◽  
Taigen Sase ◽  
...  
Keyword(s):  
Enteral Nutrition ◽  
Hospital Stay ◽  
Acute Phase ◽  
Hospital Costs ◽  
Liquid Diet ◽  
Hospital Infection ◽  
Stroke Patients ◽  
The Mean ◽  
The Impact ◽  
Selection Of

Background: Infection is a common complication after stroke and is strongly associated with an unfavorable functional outcome of patients. Although nutritional intervention reduces the risk of post-operative infection, the impact of differences of products has not been clarified. Less examination of infection and use of antibiotics not only show a high-quality care. In DPC hospital (Japanese style of DRG / PPS), it is important from the hospital management point of view to reduce the comprehensive costs such as medicines and inspections as much as possible. The purpose of this study is to investigate whether the selection of enteral nutrition in the acute phase of stroke patients can contribute to inflectional control and hospital costs. Methods: Retrospective analysis in a single center was performed in 50 acute stroke patients who were received enteral nutrition from April 2017 to March 2019. Nutrients gradually over 7 days of hospitalization, the patients were classified into two groups: 1.0-group (general nutrition 1.0 kcal/mL, 25 patients) and 1.5+α-group (started with high protein whey peptide-digested liquid diet (1.5 kcal/mL) and were, later, switched to highly fermentable dietary fiber contained liquid diet (1.5 kcal/mL) after 4 days, 25 patients). Lengths of hospital stay, days of antibiotic use (except during intraoperative), serious infection including methicillin-resistant Staphylococcus aureus , Extended spectrum β -lactamase producing Enterobacteriaceae and Clostridium difficile infection, and total medical costs were analyzed. Results: The baseline characteristics were similar in the both groups. The mean of lengths of hospital stay were 48.0 and 47.8 days in 1.0-group and 1.5+α-group, respectively. The mean of days of antibiotics use during hospitalization in 1.0-group (16.5 days (34.4%)) were larger than that in 1.5+α-group (11.3 days (23.6%)). The serious infections were developed in six and four cases in 1.0-group and 1.5+α-group, respectively. The total hospital costs were reduced by approximately 500 USD/patient in 1.5+α group as compared to 1.0 group. Conclusions: The selection of enteral nutrition in the acute phase of stroke patients affects the risk of in-hospital infection and reduces hospital costs.

Seasonality in the reproductive activity of male chinchillas on a breeding farm in the climatic conditions of southern Poland

2017 ◽  
Vol 13 (4) ◽  
pp. 17-27
Author(s):  
Olga Szeleszczuk ◽  
Aleksandra Kowalczyk ◽  
Alicja Satoła
Keyword(s):  
Reproductive Potential ◽  
Reproductive Activity ◽  
Climatic Conditions ◽  
Low Fertility ◽  
The Mean ◽  
Foundation Stock ◽  
Modern Breeding ◽  
The Impact ◽  
Strict Selection ◽  
Selection Of

Farmed chinchillas continue to have very low fertility and prolificacy, although the reproductive potential of females is much higher and can be exploited. An increasing number of studies deal with the specific nature of reproduction in this species, with particular focus on female fertility. However, there is a lack of analyses and studies of males. Therefore, this study has attempted to determine the impact of the season of the year on the reproductive activity of male chinchillas and on the results of their use for breeding in the period from January 1991 to December 1996. The analysis was conducted on farmed animals on one of the largest farms in Poland. The farm was established in 1991 with an initial foundation stock of about 150 females and 25 males. Breeding was based on animals imported from a reputable farm in Germany, from which modern breeding technologies were adopted as well. Polygamous breeding with 6 females per male is used. Sexual activity was varied between years. Taking into account the entire foundation stock, an average of 8.15 litters and 14.77 pups were obtained per male per year. Analysis of five selected males revealed higher values: the mean number of litters ranged from 7.13 to 11.8 and the litter size ranged from 1.9 to 2.59. Thus, better utilization of males for breeding is possible on chinchilla farms. The system of keeping a male with many females at the same time enables strict selection of males.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Sound Production Treatment for Acquired Apraxia of Speech: An Examination of Dosage in Relation to Probe Performance

2020 ◽  
pp. 1-16
Author(s):  
Julie L. Wambaugh ◽  
Lydia Kallhoff ◽  
Christina Nessler
Keyword(s):  
Retrospective Analysis ◽  
Sound Production ◽  
Apraxia Of Speech ◽  
Practice Schedule ◽  
Practice Schedules ◽  
Baseline Performance ◽  
The Mean ◽  
Number Of Treatment ◽  
The Impact

Purpose This study was designed to examine the association of dosage and effects of Sound Production Treatment (SPT) for acquired apraxia of speech. Method Treatment logs and probe data from 20 speakers with apraxia of speech and aphasia were submitted to a retrospective analysis. The number of treatment sessions and teaching episodes was examined relative to (a) change in articulation accuracy above baseline performance, (b) mastery of production, and (c) maintenance. The impact of practice schedule (SPT-Blocked vs. SPT-Random) was also examined. Results The average number of treatment sessions conducted prior to change was 5.4 for SPT-Blocked and 3.9 for SPT-Random. The mean number of teaching episodes preceding change was 334 for SPT-Blocked and 179 for SPT-Random. Mastery occurred within an average of 13.7 sessions (1,252 teaching episodes) and 12.4 sessions (1,082 teaching episodes) for SPT-Blocked and SPT-Random, respectively. Comparisons of dosage metric values across practice schedules did not reveal substantial differences. Significant negative correlations were found between follow-up probe performance and the dosage metrics. Conclusions Only a few treatment sessions were needed to achieve initial positive changes in articulation, with mastery occurring within 12–14 sessions for the majority of participants. Earlier occurrence of change or mastery was associated with better follow-up performance. Supplemental Material https://doi.org/10.23641/asha.12592190

Methods for Restricting Maximum Exposure Rate in Computerized Adaptative Testing

Methodology ◽  
2007 ◽  
Vol 3 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Juan Ramon Barrada ◽  
Julio Olea ◽  
Vicente Ponsoda
Keyword(s):  
Measurement Accuracy ◽  
Computerized Adaptive Testing ◽  
Computation Time ◽  
Adaptive Testing ◽  
Exposure Rate ◽  
Control Parameters ◽  
The Impact ◽  
Two Alternatives ◽  
Selection Of ◽  
Maximum Exposure

Abstract. The Sympson-Hetter (1985) method provides a means of controlling maximum exposure rate of items in Computerized Adaptive Testing. Through a series of simulations, control parameters are set that mark the probability of administration of an item on being selected. This method presents two main problems: it requires a long computation time for calculating the parameters and the maximum exposure rate is slightly above the fixed limit. Van der Linden (2003) presented two alternatives which appear to solve both of the problems. The impact of these methods in the measurement accuracy has not been tested yet. We show how these methods over-restrict the exposure of some highly discriminating items and, thus, the accuracy is decreased. It also shown that, when the desired maximum exposure rate is near the minimum possible value, these methods offer an empirical maximum exposure rate clearly above the goal. A new method, based on the initial estimation of the probability of administration and the probability of selection of the items with the restricted method ( Revuelta & Ponsoda, 1998 ), is presented in this paper. It can be used with the Sympson-Hetter method and with the two van der Linden's methods. This option, when used with Sympson-Hetter, speeds the convergence of the control parameters without decreasing the accuracy.

Impact of changing rainfall conditions on surface and groundwater resources in an experimental watershed in Greece

2013 ◽  
Vol 12 (2) ◽  
pp. 119-125
Keyword(s):  
Groundwater Resources ◽  
Annual Runoff ◽  
Annual Rainfall ◽  
Rainfall Regime ◽  
Winter Rainfall ◽  
Rainfall Depth ◽  
Rainfall Volume ◽  
The Mean ◽  
Groundwater Reserves ◽  
The Impact

The present study concerns the impact of a change in the rainfall regime on surface and groundwater resources in an experimental watershed. The research is conducted in a gauged mountainous watershed (15.18 km2) that is located on the eastern side of Penteli Mountain, in the prefecture of Attica, Greece and the study period concerns the years from 2003 to 2008. The decrease in the annual rainfall depth during the last two hydrological years 2006-2007, 2007-2008 is 10% and 35%, respectively, in relation to the average of the previous years. In addition, the monthly distribution of rainfall is characterized by a distinct decrease in winter rainfall volume. The field measurements show that this change in rainfall conditions has a direct impact on the surface runoff of the watershed, as well as on the groundwater reserves. The mean annual runoff in the last two hydrological years has decreased by 56% and 75% in relation to the average of the previous years. Moreover, the groundwater level follows a declining trend and has dropped significantly in the last two years.

Der Sommer und Herbst 2003 aus phänologischer Sicht | Summer and autumn 2003 from a phenological point of view

2004 ◽  
Vol 155 (5) ◽  
pp. 142-145 ◽  
Author(s):  
Claudio Defila
Keyword(s):  
Time Series ◽  
New Record ◽  
Point Of View ◽  
Late Spring ◽  
Mean Deviation ◽  
Leaf Shedding ◽  
The Mean ◽  
Very High ◽  
Selection Of

The record-breaking heatwave of 2003 also had an impact on the vegetation in Switzerland. To examine its influences seven phenological late spring and summer phases were evaluated together with six phases in the autumn from a selection of stations. 30% of the 122 chosen phenological time series in late spring and summer phases set a new record (earliest arrival). The proportion of very early arrivals is very high and the mean deviation from the norm is between 10 and 20 days. The situation was less extreme in autumn, where 20% of the 103 time series chosen set a new record. The majority of the phenological arrivals were found in the class «normal» but the class«very early» is still well represented. The mean precocity lies between five and twenty days. As far as the leaf shedding of the beech is concerned, there was even a slight delay of around six days. The evaluation serves to show that the heatwave of 2003 strongly influenced the phenological events of summer and spring.

Caracterização da Peneira Média em Clones de Coffea canephora

REVISTA FIMCA ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. 28-31
Author(s):  
Darlan Darlan Sanches Barbosa Alves ◽  
Victor Mouzinho Spinelli ◽  
Marcos Santana Moraes ◽  
Carolina Augusto De Souza ◽  
Rodrigo da Silva Ribeiro ◽  
...  
Keyword(s):  
Genetic Improvement ◽  
Block Design ◽  
Coffea Canephora ◽  
Coffee Production ◽  
Randomized Block Design ◽  
Significant Difference ◽  
The Mean ◽  
Four Blocks ◽  
Selection Of

Introdução: O estado de Rondônia se destaca como tradicional produtor de café, sendo o segundo maior produtor brasileiro de C. canephora. No melhoramento genético de C. canephora, a seleção de plantas de elevada peneira média está associada à bebida de qualidade superior. Objetivos: O objetivo desse estudo foi avaliar a variabilidade genética de clones de C. canephora para o tamanho dos grãos, mensurado a partir da avaliação da peneira média (PM). Materiais e Métodos: Para isso, foi conduzido ao longo de dois anos agrícolas experimento no campo experimental da Embrapa no município de Ouro Preto do Oeste-RO, para a avaliação da peneira média de 130 genótipos (clones) com características das variedades botânicas Conilon, Robusta e híbridos intervarietais. O delineamento experimental utilizado foi de blocos ao acaso, com quatro repetições de quatro plantas por parcela. Resultados: Não houve resultados significativos para a interação clones X anos, indicando uma maior consistência no comportamento das plantas ao longo do tempo. Porém foram observadas diferenças significativas para o tamanho dos grãos entre os genótipos avaliados, possibilitando selecionar genótipos superiores. Conclusão: Os genótipos agruparam-se em cinco classes de acordo com o teste de média, subsidiando a caracterização de um gradiente de variabilidade da característica avaliada ABSTRACTIntroduction: Coffea canephora accounts for approximately 35% of the world's coffee production. The state of Rondônia stands out as a traditional coffee producer, being the second largest Brazilian producer of C. canephora. In the classical genetic improvement of C. anephora, the selection of plants of high average sieve is associated with a drink of superior quality. Objectives: The objective of this udy was to evaluate the genetic variability of Coffea canephora clones for the agronomic medium sieve (PM). Materials and Methods: The experiment was conducted in the experimental field of Embrapa, municipality of OuroPreto do Oeste-RO, located at coordinates 10º44'53 "S and 62º12'57". One hundred thirty genotypes (clones) of botanical characteristics Conilon, Robusta and intervarietal hybrids were evaluated in the agricultural years 2013-2014 and 2014-2015. The experimental design was a randomized block design with four blocks and four plants per plot, spacing 3.5 x 1.5 meters between plants. Results: Significant difference was found for the grain size. According to the F test, at 5% probability, the genotypes were grouped into five classes according to the mean test. Conclusion: The results obtained subsidized the characterization of a variability gradient of the evaluated trait.

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