scholarly journals A Modest Approach to Markov Automata

2021 ◽  
Vol 31 (3) ◽  
pp. 1-34
Author(s):  
Yuliya Butkova ◽  
Arnd Hartmanns ◽  
Holger Hermanns
Keyword(s):  
Model Checking ◽  
The State ◽  
Straightforward Application ◽  
Long Run ◽  
Simulation Based ◽  
Detailed Evaluation ◽  
High Level ◽  
Stochastic Time ◽  
Markov Automata ◽  
Long Run Average Reward

Markov automata are a compositional modelling formalism with continuous stochastic time, discrete probabilities, and nondeterministic choices. In this article, we present extensions to M ODEST , an expressive high-level language with roots in process algebra, that allow large Markov automata models to be specified in a succinct, modular way. We illustrate the advantages of M ODEST over alternative languages. Model checking Markov automata models requires dedicated algorithms for time-bounded and long-run average reward properties. We describe and evaluate the state-of-the-art algorithms implemented in the mcsta model checker of the M ODEST T OOLSET . We find that mcsta improves the performance and scalability of Markov automata model checking compared to earlier and alternative tools. We explain a partial-exploration approach based on the BRTDP method designed to mitigate the state space explosion problem of model checking, and experimentally evaluate its effectiveness. This problem can be avoided entirely by purely simulation-based techniques, but the nondeterminism in Markov automata hinders their straightforward application. We explain how lightweight scheduler sampling can make simulation possible, and provide a detailed evaluation of its usefulness on several benchmarks using the M ODEST T OOLSET ’s modes simulator.

scholarly journals Fragility of State in Central African Republic: An Econometric Approach to Efficiency Understanding

2018 ◽  
Vol 21 (3) ◽  
pp. 681-697
Author(s):  
Yapatake Kossele Thales Pacific
Keyword(s):  
Central African Republic ◽  
Negative Impact ◽  
Positive Impact ◽  
The State ◽  
Policy Implications ◽  
Long Run ◽  
Short Run ◽  
High Level ◽  
The Impact ◽  
Control Of Corruption

A fragile state contributes to the underdevelopment of the nation and its consequences can be very devastating on the state’s cohesion, characterized by a high level of corruption which led the country to an incessant political instability and the continuous presence of foreign troops. 1 This article used the vector autoregresssion (VAR) model covering the period of 2005–2015 to examine the impact of control of corruption on the fragility of the state in the Central African Republic (CAR). The results show that control of corruption is significant and has a negative impact on the fragility of the state in the short run. The impulse response shows a negative impact of control of corruption in the short run but a positive impact in the long run on the fragility of the state. The policy implications of this fragility are that the CAR must pursue better governance as well as in the investment choices. Unless the CAR leaders and citizens recognize their own fragility, things can only get worse.

scholarly journals Multi-objective Optimization of Long-run Average and Total Rewards

2021 ◽  
pp. 230-249
Author(s):  
Tim Quatmann ◽  
Joost-Pieter Katoen
Keyword(s):  
Model Checking ◽  
Multi Objective ◽  
Compositional Model ◽  
Total Reward ◽  
Long Run ◽  
Total Rewards ◽  
Markov Decision ◽  
Objective Model ◽  
Improved Performance ◽  
Markov Automata

AbstractThis paper presents an efficient procedure for multi-objective model checking of long-run average reward (aka: mean pay-off) and total reward objectives as well as their combination. We consider this for Markov automata, a compositional model that captures both traditional Markov decision processes (MDPs) as well as a continuous-time variant thereof. The crux of our procedure is a generalization of Forejt et al.’s approach for total rewards on MDPs to arbitrary combinations of long-run and total reward objectives on Markov automata. Experiments with a prototypical implementation on top of the Storm model checker show encouraging results for both model types and indicate a substantial improved performance over existing multi-objective long-run MDP model checking based on linear programming.

Multidimensional analysis of the state of Russian studies on the education issues over 1993–2016

2018 ◽  
pp. 50-62
Author(s):  
Дмитрий Рубвальтер ◽  
Dmitry Rubvalter ◽  
Александр Либкинд ◽  
Alexander Libkind ◽  
Валентина Маркусова ◽  
...  
Keyword(s):  
Web Of Science ◽  
The State ◽  
Multidimensional Analysis ◽  
Russian Regions ◽  
Global Flow ◽  
Educational Issues ◽  
Foreign Countries ◽  
High Level ◽  
The Web ◽  
Made In

A multidimensional analysis of the state of Russian studies on the education issues over 1993–2016 was carried out based on the materials of the data contained in the Web of Science (SSCI, A & HCI and SCI-E databases). There were determined the dynamics and trends of a number of relevant indicators, such as the number of Russian publications by year, the share of these publications in the global flow of publications on education issues, the dynamics of the share of publications made in co-authorship with foreign colleagues, etc. A number of distributions of Russian publications on educational issues was compiled and analyzed: by journals, by Russian regions and cities, by organizations and authors of the publications. It was found that most of these distributions were characterized by a high level of non-uniformity. A list of journals (125 titles) in which Russian works on education issues had been published was compiled. Russian organizations (308) and domestic researchers (about two thousand) engaged in studying the issues of education were identified. It was discovered that more than 200 organizations and about 400 academicians from 60 foreign countries had participated in Russian studies on the education issues.

scholarly journals New delay-dependent observer-based control for uncertain stochastic time-delay systems

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Xiu-feng Miao ◽  
Long-suo Li
Keyword(s):  
Time Delay ◽  
The State ◽  
Delay Systems ◽  
Linear Matrix ◽  
Time Delay Systems ◽  
Parameter Uncertainties ◽  
Noise Disturbances ◽  
System States ◽  
Delay Dependent ◽  
Stochastic Time

AbstractThis paper considers the problem of estimating the state vector of uncertain stochastic time-delay systems, while the system states are unmeasured. The system under study involves parameter uncertainties, noise disturbances and time delay, and they are dependent on the state. Based on the Lyapunov–Krasovskii functional approach, we present a delay-dependent condition for the existence of a state observer in terms of a linear matrix inequality. A numerical example is exploited to show the validity of the results obtained.

Institutional variations in practice of demand responsive approach: evidence from rural water supply in India

Water Policy ◽  
2014 ◽  
Vol 16 (4) ◽  
pp. 650-668 ◽  
Author(s):  
Satyapriya Rout
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Rural Areas ◽  
The State ◽  
Indian Society ◽  
Institution Building ◽  
Rural Water Supply ◽  
Long Run ◽  
Rural Water ◽  
Village Communities

The paper reports the main findings of a study, designed to develop a better understanding of institutional variations in working with the demand responsive approach (DRA) in rural water supply in the state of Odisha in India. Data for the paper were collected from twelve village communities, where water is being supplied either through their community based institution or through the local government institution of the Gram Panchayat. The findings suggest that the two types of institutions performed differently in implementing the DRA. It depicted that the DRA under the broader rubric of institutional reforms in the water sector has failed to address the question of social inequality, and rather had reinforced and extended the already existing inequity of Indian society to access to safe and secure drinking water in rural areas. The study highlights that participation, cost recovery, full operation and management transfer may be an efficient proposition, but not sustainable in the long run without proper investment in institution building and support from the state, especially in provisioning of basic services like drinking water to rural poor.

scholarly journals Courage and Cowardice in the North African Campaign: The Eighth Army and Defeat in the Summer of 1942

2013 ◽  
Vol 20 (1) ◽  
pp. 99-122 ◽  
Author(s):  
Jonathan Fennell
Keyword(s):  
North Africa ◽  
The State ◽  
The Other ◽  
Human Dimension ◽  
North African ◽  
The North ◽  
High Level ◽  
Eighth Army

High rates of desertion and surrender during the battles in North Africa in the summer of 1942 were a major factor in Eighth Army’s poor combat performance. At the time, some suggested that these problems were symptomatic of a lack of courage or even of cowardice. There are two broad strands to the conceptualization of courage and cowardice. One focuses on the willingness of the person to fight; the other puts emphasis on how actions express an individual’s ability to cope with fear. Whichever conceptualization is used, high morale motivates the soldier to fight and shields the ordinary recruit from his fear, preventing it from overcoming him in battle. Where morale fails, the soldier is left demotivated and burdened with his terror and, therefore, and is therefore prone to desertion or surrender. Because it is extremely difficult to maintain morale at a continuously high level in an environment governed by chance and managed by humans, all soldiers can find themselves in situations where their actions may be judged as cowardly. Alternatively, if they are properly motivated to fight and prepared by the state and military to deal with the unavoidable fear of combat, all soldiers can be labelled courageous. Accordingly, emotive terms should be avoided when attempting to describe rationally explainable outcomes. The undoubtedly negative connotations attached to cowardice in battle and the positive ones attached to courage are, therefore, arguably unhelpful in understanding Eighth Army’s performance in the summer of 1942 and the human dimension in warfare more generally.

Analysis of the state of the migration process of the ukrainian population in the context of domestic and international levels

2021 ◽  
Vol 72 (5) ◽  
pp. 110-118
Author(s):  
M. Shkurat ◽  
K. Pavlotska
Keyword(s):  
Social Protection ◽  
Negative Impact ◽  
Migration Policy ◽  
Cash Flows ◽  
The State ◽  
Negative Consequences ◽  
Migration Process ◽  
State Of The Economy ◽  
Migration Flows ◽  
High Level

Analysis of the migration process of the Ukrainian population, which takes place within the state and at the international level during 2014–2019 is carried out in this paper. On the basis of scientific works of domestic scientists and institutes the problems which have not been investigated, and also aspects which have been solved partially are defined. The negative consequences of the Ukrainian migration process on the state of the country are identified. The classification of migration flows of the Ukrainian population according to the reasons of movement is carried out. The main regions and countries which, as of the beginning of 2021, are more attractive to compatriots and are characterized by significant influxes of Ukrainians are identified. The main centers of departure – regions and countries – which are characterized by high level of outflow of Ukrainians are determined, the main problems and reasons that motivate the outflow of Ukrainians are highlighted in this paper. The level of growth of the Ukrainian population in terms of migration flows is defined. The investigation of Ukrainian diasporas, territorial location and analysis of their share in comparison is carried out. The main factors that force the Ukrainian population to move, which affects the demographic situation in Ukraine, the level of employment, as well as the amount of cash flows to the country and the state of the economy as a whole are identified. The main regulations and identified solutions to the migration flows of the domestic population, which were approved and implemented in the period from 2001 to 2019 are compared in this paper. On the basis of current and newly introduced strategies, critical analysis of the ways of regulating the migration process of the Ukrainian population is carried out, the main aspects and problems of the implemented migration policy of Ukraine are determined. The results of the work are to identify the main ways to reduce the negative impact of the migration process on the country's economy and related processes, and strategies to benefit from the movement of citizens of Ukraine, namely: introduction of intellectual security, revision of wages by region, stimulating the process of attracting technology in all spheres of activity and formation of the social protection system.

Can Russia Fight Organized Crime and Corruption?

2002 ◽  
Vol 23 (2) ◽  
pp. 37-55
Author(s):  
Louise I. Shelley
Keyword(s):  
Organized Crime ◽  
Local Level ◽  
The State ◽  
The Political ◽  
Political Will ◽  
Structural Problems ◽  
Economic Elite ◽  
High Level ◽  
Personal Interests

The murder of Valentin Tsvetkov, the governor of Magadan in central Moscow in broad day light in October 2002 highlights that organized crime and corruption are still alive and well and highly destructive of life and governance in Russia (Wines, 2002). His murder once again raises the question, “Why has Russia not been able to stop organized crime and high level corruption?” The answer is that Russia docs not have the political will at the national, regional or local level to fight these problems. This is true because the Kremlin and economic elite push their personal interests over those of the state and the society. Structural problems such as low salaries of state personnel and the embedding of organized crime and corruption make reform very difficult.

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