A first order approach to a class of multi-time-period stochastic programming problems

1986 ◽  
pp. 103-117 ◽  
Author(s):  
E. M. L. Beale ◽  
G. B. Dantzig ◽  
R. D. Watson
Keyword(s):  
Stochastic Programming ◽  
First Order ◽  
Time Period

scholarly journals In Vitro Release Kinetics Study of Different Brands of Esomeprazole Sustained Release Tablets Available in Bangladesh

1970 ◽  
Vol 2 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Abul Kalam Lutful Kabir ◽  
Tasbira Jesmeen ◽  
Md Mesbah Uddin Talukder ◽  
Abu Taher Md Rajib ◽  
DM Mizanur Rahman
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Release Kinetics ◽  
Matrix Tablets ◽  
In Vitro Dissolution ◽  
National Brand ◽  
First Order ◽  
Time Period ◽  
Esomeprazole Magnesium

Commercially available four national and four international brands of esomeprazole magnesium sustained release matrix tablets were studied in simulated gastric medium (pH 1.2) for 2 hours and simulated intestinal medium (pH 6.8) for 8 hours time period using USP reference dissolution apparatus. All the national and international brands complied with the USP in-vitro dissolution specifications for drug release in simulated gastric medium. However, one of the national brands (Code: MP-1) and one of the international brands (MP-7) failed to fulfill the official requirement of 80% drug release within 8th hour in simulated intestinal medium. Drug release of that national and international brand were 70.49% and 67.05% respectively within the specified time period, however one national brand (Code: MP-4) released 103.46 % drug within 8th hour in intestinal medium. Drug release profiles were analyzed for zero order, first order and Higuchi equation to reveal the release kinetics perspective of esomeprazole magnesium sustained release matrix tablets. It was found that zero order release kinetics was the predominant release mechanism than first order and Higuchi release kinetics for those brands (Code: MP-2, MP-3, MP-4, MP-5, MP-6 and MP-8) which complied with the USP in vitro dissolution specification for drug releases. On the other hand, first order release kinetics was predominant for one national and also one international non compliant brands (Code: MP-1 and MP-6). Key Words: In vitro dissolution; Sustained release; Market preparations; Kinetic analysis; Esomeprazole; National brand; International brand. DOI: 10.3329/sjps.v2i1.5812Stamford Journal of Pharmaceutical Sciences Vol.2(1) 2009: 27-31

scholarly journals A Generic First-Order Radiative Transfer Modelling Approach for the Inversion of Soil and Vegetation Parameters from Scatterometer Observations

2019 ◽  
Vol 11 (3) ◽  
pp. 285 ◽  
Author(s):  
Raphael Quast ◽  
Clément Albergel ◽  
Jean-Christophe Calvet ◽  
Wolfgang Wagner
Keyword(s):  
Radiative Transfer ◽  
Land Surface ◽  
Distribution Functions ◽  
Surface Model ◽  
Parameter Estimates ◽  
Area Index ◽  
First Order ◽  
Time Period ◽  
Transfer Modelling ◽  
Modelling Approach

We present the application of a generic, semi-empirical first-order radiative transfer modelling approach for the retrieval of soil- and vegetation related parameters from coarse-resolution space-borne scatterometer measurements ( σ 0 ). It is shown that both angular- and temporal variabilities of ASCAT σ 0 measurements can be sufficiently represented by modelling the scattering characteristics of the soil-surface and the covering vegetation-layer via linear combinations of idealized distribution-functions. The temporal variations are modelled using only two dynamic variables, the vegetation optical depth ( τ ) and the nadir hemispherical reflectance (N) of the chosen soil-bidirectional reflectance distribution function ( B R D F ). The remaining spatial variabilities of the soil- and vegetation composition are accounted for via temporally constant parameters. The model was applied to series of 158 selected test-sites within France. Parameter estimates are obtained by using ASCAT σ 0 measurements together with auxiliary Leaf Area Index ( L A I ) and soil-moisture ( S M ) datasets provided by the Interactions between Soil, Biosphere, and Atmosphere (ISBA) land-surface model within the SURFEX modelling platform for a time-period from 2007–2009. The resulting parametrization was then used used to perform S M and τ retrievals both with and without the incorporation of auxiliary L A I and S M datasets for a subsequent time-period from 2010 to 2012.

Criteria for the a Priori Shortest Path Generation in Uncertain Time-Varying Transportation Networks

2015 ◽  
Vol 23 (06) ◽  
pp. 807-827 ◽  
Author(s):  
Li Wang ◽  
Ziyou Gao ◽  
Lixing Yang
Keyword(s):  
A Priori ◽  
Time Interval ◽  
Time Varying ◽  
Uncertain Measure ◽  
First Order ◽  
Dominance Rule ◽  
Time Period ◽  
Comparison Criteria ◽  
Definition Of ◽  
Uncertain Time

This paper proposes a new definition of uncertain time-varying network to capture the uncertain and dynamic characteristics of the network with discrete uncertain link travel times. To find the a priori non-dominated paths in this type of network, three comparison criteria based on the uncertain measure, namely, deterministic dominance rule, first-order uncertain dominance rule and uncertain expected value dominance rule, are proposed to generate non-dominated paths in a single time interval and a time period, as more than one path may exist between an origin and destination for a given departure time. The proposed comparison methods are then applied to solving a simple uncertain time-varying network. The computational results verify the efficiency of three dominance rules for finding non-dominated paths.

scholarly journals Formulation of Two-Stage Stochastic Programming with Fixed Recourse

2019 ◽  
Vol 1 (1) ◽  
pp. 18-21
Author(s):  
Hashnayne Ahmed
Keyword(s):  
Stochastic Programming ◽  
Objective Function ◽  
Past Experience ◽  
Optimization Techniques ◽  
Random Parameters ◽  
Two Stage ◽  
Second Stage ◽  
Multi Stage ◽  
Time Period ◽  
Primary Model

Stochastic Programming is an asset for the next world researchers due to its uncertainty calculations, which has been skipped in deterministic world experiments as it includes complicated calculations. Two-stage stochastic programming concerns two time period decisions based on some random parameters obtained from past experience or some sort of survey. The objective function for formulating two-stage stochastic programming with fixed recourse includes two parts: first-stage forecast and second-stage fixed decisions based on the experiment results. The constraints are similar to the normal optimization techniques rather some adjustments of requirements and technology assets. The fixed recourse decisions are sort of decisions from the deterministic world.  Formulation techniques of two-stage stochastic programming with fixed recourse may be used for further complications arises in stochastic programming like complete recourse problems, multi-stage problems, etc. And that’s why Two-stage stochastic programming with fixed recourse is called the primary model for stochastic programming.

scholarly journals Study of the Oxidative Forced Degradation of Glutathione in Its Nutraceutical Formulations Using Zone Fluidics and Green Liquid Chromatography

Separations ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 16
Author(s):  
Apostolia Tsiasioti ◽  
Constantinos K. Zacharis ◽  
Anastasia-Stella Zotou ◽  
Paraskevas D. Tzanavaras
Keyword(s):  
Reversed Phase ◽  
Hplc Method ◽  
Forced Degradation ◽  
Oxidized Glutathione ◽  
Reversed Phase Hplc ◽  
First Order ◽  
Direct Uv Detection ◽  
First Order Kinetics ◽  
Time Period ◽  
Pseudo First Order

In the present study, we report the results of our investigation of the oxidative forced degradation of glutathione in its nutraceutical formulations by two validated analytical methods. The first is based on the reaction of glutathione with o-phthalaldehyde through an automated zone fluidics flow platform and fluorimetric detection (λex/λem = 340/425 nm). The second is based on the separation of glutathione and its oxidation product by a green reversed-phase HPLC method coupled to direct UV detection, at 210 nm. A solution of 3% w/v H2O2 provided fast oxidation of more than 95% of glutathione to yield oxidized glutathione in a time period of 180 min. The mechanism of the oxidation was proved to follow pseudo-first order kinetics. The k, t90 and t1/2 values were calculated.

scholarly journals Formulation of Two-Stage Stochastic Programming with Fixed Recourse

2019 ◽  
Author(s):  
Hashnayne Ahmed
Keyword(s):  
Stochastic Programming ◽  
Objective Function ◽  
Past Experience ◽  
Optimization Techniques ◽  
Random Parameters ◽  
Two Stage ◽  
Second Stage ◽  
Multi Stage ◽  
Time Period ◽  
Primary Model

Stochastic Programming is an asset for the next world researchers due to its uncertainty calculations, which has been skipped in deterministic world experiments as it includes complicated calculations. Two-stage stochastic programming concerns two time period decisions based on some random parameters obtained from past experience or some sort of survey. The objective function for formulating two-stage stochastic programming with fixed recourse includes two parts: first-stage forecast and second-stage fixed decisions based on the experiment results. The constraints are similar to the normal optimization techniques rather some adjustments of requirements and technology assets. The fixed recourse decisions are sort of decisions from the deterministic world. Formulation techniques of two-stage stochastic programming with fixed recourse may be used for further complications arises in stochastic programming like complete recourse problems, multi-stage problems, etc. And that’s why Two-stage stochastic programming with fixed recourse is called the primary model for stochastic programming.

Dual systems for all: Higher-order, role-based relational reasoning as a uniquely derived feature of human cognition

2019 ◽  
Vol 42 ◽  
Author(s):  
Daniel J. Povinelli ◽  
Gabrielle C. Glorioso ◽  
Shannon L. Kuznar ◽  
Mateja Pavlic
Keyword(s):  
Temporal Reasoning ◽  
Higher Order ◽  
Important Case ◽  
Human Cognition ◽  
Relational Reasoning ◽  
Dual Systems ◽  
First Order ◽  
Reasoning System ◽  
Role Based

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.

The Tempo and mode(S) of Prebiotic Evolution

1997 ◽  
Vol 161 ◽  
pp. 419-429 ◽  
Author(s):  
Antonio Lazcano
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Biological Evolution ◽  
Current Evidence ◽  
Early Diversification ◽  
Time Period ◽  
The Galaxy ◽  
History Of ◽  
Widespread Phenomenon ◽  
The Origin Of Life

AbstractDifferent current ideas on the origin of life are critically examined. Comparison of the now fashionable FeS/H2S pyrite-based autotrophic theory of the origin of life with the heterotrophic viewpoint suggest that the later is still the most fertile explanation for the emergence of life. However, the theory of chemical evolution and heterotrophic origins of life requires major updating, which should include the abandonment of the idea that the appearance of life was a slow process involving billions of years. Stability of organic compounds and the genetics of bacteria suggest that the origin and early diversification of life took place in a time period of the order of 10 million years. Current evidence suggest that the abiotic synthesis of organic compounds may be a widespread phenomenon in the Galaxy and may have a deterministic nature. However, the history of the biosphere does not exhibits any obvious trend towards greater complexity or «higher» forms of life. Therefore, the role of contingency in biological evolution should not be understimated in the discussions of the possibilities of life in the Universe.

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