system dynamic
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Atefeh Mousavi ◽  
Mehdi Mohammadzadeh ◽  
Hossein Zare

The purpose of this study is to identify elements that influence the sale of generic pharmaceutical products during their life cycle in order to achieve more comprehensive planning and to prevent a decline stage of the product life cycle (PLC). We used a system dynamic model to identify the behaviors of demand, supply, and competition as three major subsystems of PLC in generic pharmaceutical products. We first investigated the PLC patterns of 527 medicines to identify their “reference mode”, determined the causal loop of the pharmaceuticals phase of PLC based on both an in-depth literature review and experts’ opinions, and finally simulated a quantitative dynamic model based on real-world data between 2012 and 2019 from Iran. Based on the results, “total demand and accurate forecasting”, “marketing efforts”, and “R and D activities of a firm” are the most critical factors involved in the formation of a generic drug PLC. An increase of 20–50% of manufacturers’ marketing and R and D activities can raise sales by more than 50% in the decline stage of the PLC. The product life cycle can give generic manufacturers more insights into the processes leading to declining sales of their products. PLC may help to prevent a product from entering the decline stage even if the total demand for a generic drug is dropping in the market.

2022 ◽  
Vol 21 ◽  
pp. 44-50
Valeriy Kozytskyy ◽  
Nelya Pabyrivska ◽  
Galyna Beregova

The economies of almost every country in the whole word have been suffered from coronavirus pandemic consequences. The damage was especially hard for labor markets. The large magnitude of demand and production shocks that was caused by COVID-19 significantly disturbed the dynamics of output, wages and prices. The research problem addressed in this paper focuses on dynamic properties of wages and prices behavior influenced by shocks with different magnitudes and types. We apply a system dynamic approach to conduct the simulations of economic variables and investigate the possibility of their convergence to some stable path. We examine the impact of demand and production shocks on the output and prices as well as on wage and inflation behavior. It is proved that values of models parameters are crucial for existing of new steady state and convergence of economic variables. The paper determines the bifurcation points that separate different modes of transition period in moving towards or away from equilibrium. The research includes the investigation of the impact of economy’s original state and emphasizes the importance of initial point of the system for the next its dynamics after shock. The research results derived in the paper serves as a useful learning tool to develop a discussion of the policy design issues related to reduction of negative impact of severe and unanticipated disturbance like COVID-19.

Juan Fang ◽  
Qiangang Zheng ◽  
Haibo Zhang

The on-board dynamic model is the basis of numerous advanced control technologies for modern aero-engine, and its accuracy and real-time performance are two crucial indicators. Since the simulation accuracy declines with the deviation from the ground point of the conventional compact propulsion system dynamic model (CPSDM), an improved CPSDM (ICPSDM) based on deep neural network is proposed in this paper. First, the K-means algorithm is utilized to get the sampling point, and the engine simulation data is collected in the cluster centers. Then, the batch normalize deep neural network (BN-DNN) is applied to build the ICPSDM, which can shorten the training time tremendously. The simulation results show that, in the same simulation environment, the accuracy of turbine inlet temperature T 4 , fan surge margin SMc, thrust F, and specific fuel consumption SFC calculated by ICPSDM are 11.04, 3.17, 1.89, and 1.98 times of CPSDM, respectively, at off-design point, and the real-time performance of ICPSDM is more than 30 times faster than the component-level model.

M. V. Cherkunova ◽  
E. V. Ponomarenko

The article is devoted to the study of modern mini-format literary works of English web literature. This subject is addressed due to the fact that there exists an urgent need to study ways of ensuring effective communication in the light of modern tendencies of verbal optimization of the cognitive processes and the reduction of the physical length of the texts. Mini-texts of web literature are considered from the standpoint of the system-dynamic approach, namely from the point of view of the dynamics of the formation of a complex semantic construct in the process of interaction and mutual influence of different-level elements of the discourse system, including the factors of the exterior environment. The methods of discourse, contextual and linguosynergetic analysis are employed for the analysis of the texts, which allows to understand how systemic interaction of speech elements within a small-format text is organized. In particular, the article describes the mechanisms of the emergence of additional semantic combinations due to the interdiscursive interaction at the level of form and content within the mini-format web narratives. Another mechanism of creating additional semantic structures consists in the violation of the proportionality between the structural and semantic plans of the mini-texts. Besides, attention is paid to ways of expanding the semantic plan of the discourse system due to the specific interaction of lexical operators that form the verbal layers of the text. In general, it is concluded that the synergetic interaction of different-level textual elements is of fundamental importance for ensuring pragmatic effectiveness of small-format web narratives, since on its basis an integral semantic system is formed which does not only influence the cognitive sphere of the recipients, but also is capable of fulfilling their aesthetic needs.

2021 ◽  
Vol 12 (5-2021) ◽  
pp. 117-127
Svetlana N. Malygina ◽  
Elena O. Neupokoeva ◽  

The article discusses the development of a simulation model of a production cluster by means of the Anylogic University 8.7 software tool system using agent-based and system-dynamic approaches. The authors focus on isualization tools and software implementation of algorithms for the movement of labor resources within the cluster enterprises, taking into account various restrictions.

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