Сборник докладов шестой всероссийской научно-практической конференции «Имитационное моделирование. Теория и практика» (ИММОД-2013)
The present increase of attention toward blockchain-based systems is currently reaching a tipping point with the corporate focus shifting from exploring the technology potential to creating Distributed Ledger Technology (DLT)-based systems. In light of a significant number of already existing blockchain applications driven by the Internet of Things (IoT) evolution, the developers are still facing a lack of tools and instruments for appropriate and efficient performance evaluation and behavior observation of different blockchain architectures. This paper aims at providing a systematic review of current blockchain evaluation approaches and at identifying the corresponding utilization challenges and limitations. First, we outline the main metrics related to the blockchain evaluation. Second, we propose the blockchain modeling and analysis classification based on the critical literature review. Third, we extend the review with publicly accessible industrial tools. Next, we analyze the selected results for each of the proposed classes and outline the corresponding limitations. Finally, we identify current challenges of the blockchain analysis from the system evaluation perspective, as well as provide future perspectives.
Interrelations of product perishability and supply chain resilience are studied. The major distinguishing features in a supply chain with perishable products that may affect the resilience are the risks of goods write-off. Constraints on product perishability typically result in safety stock reductions and transportation frequency increase. Consideration of the production capacity disruption risks may lead to safety stock increase. The developed simulation model was run with data of a fast moving consumer goods company and revealed novel managerial insights and practical recommendations on inventory, on-time delivery and service level control. More specifically, the evidence for adjustment of production and inventory control policies during the disruption time is provided. Otherwise the delayed and backlog orders are accumulated over the disruption time. They transit as residues into the post-disruption period and do not allow full performance and operation dynamics stabilization even after full capacity recovery. An example of such a contingency production-inventory control policy is presented.
In this paper we consider the task of inner objects mapping for the building with a bunch of moving around it autonomous agents which use narrow beam of radio waves using WiFi frequency (2.4 GHz). Linear model of pixel-wise radio waves attenuation is considered. SIRT algorithm with TV and Tikhonov regularizations is used for the task of tomography reconstruction. Properties of the presented model are studied during simulation using synthetic data consisting of 8 buildings with inner object with different shapes. Mapping quality depends on transmission power is found. Simulation results confirm suggested approach usability.
The monograph presents results by professor Dr. A. Shalumov’s Research School of Modeling, Information Technology and Automated Systems (Russia). The program, ASONIKA, developed by the school is reviewed here regarding reliability and quality of devices for simulation of electronics and chips during harmonic and random vibration, single and multiple impacts, linear acceleration and acoustic noise, and steady-state and transient thermal effects. Calculations are done for thermal stress during changes in temperature and power in time. Calculations are done for number of cycles to fatigue failure under mechanical loads as well as under cyclic thermal effects. Simulation results for reliability analysis are taken into account. Models, software interface, and simulation examples are presented.
For engineers and scientists involved in design automation of electronics.
The article describes the approach to the school timetable compilation based on genetic algorithms. Schedule requirements are divided into two categories: critical, the failure of which leads to the appearance of an incorrect, impracticable schedule, and user, allowing to consider the individual preferences of teachers and features of a school. Critical schedule requirements are described by graph theory language, which allows the use of standard genetic operators without causing many non-viable individuals. User requirements are described in the form of a flexibly adjustable fitness function, which makes it possible to quickly adapt the proposed algorithm to the conditions of a particular educational institution. The algorithm is implemented as a program for the school timetable compilation. The article presents the real data testing results, shows the correctness and advantages of the proposed approach, and marks the development trends.
This proceedings publication is a compilation of selected contributions from the “Third International Conference on the Dynamics of Information Systems” which took place at the University of Florida, Gainesville, February 16–18, 2011. The purpose of this conference was to bring together scientists and engineers from industry, government, and academia in order to exchange new discoveries and results in a broad range of topics relevant to the theory and practice of dynamics of information systems. Dynamics of Information Systems: Mathematical Foundation presents state-of-the art research and is intended for graduate students and researchers interested in some of the most recent discoveries in information theory and dynamical systems. Scientists in other disciplines may also benefit from the applications of new developments to their own area of study.
The article considers the situation when a company needs to distribute limited amount of stock to the regional warehouses in its own two-echelon distribution network. The network consists of a single distribution center and several regional facilities which are serving the company’s customers. It is supposed that every warehouse calculates its requirements for the replenishment daily basing on the on-hand inventory, demand forecast, safety stocks and lead-times from the central warehouse. Thus, company’s managers are aware of the consumption rate and inventory level at each regional facility. Demand forecasting and final replenishment planning decisions are centralized. Notion of the “limited stock” refers to such inventory quantity at the central warehouse that is insufficient to satisfy the total volume of all regional warehouses’ requirements for the product. Limited stock situation may have varying length in time. A system of rationing rules or principles should be applied to make a distribution decision in such a situation. These set of rules identify the volume and sequence of the shipments from the central to regional warehouses. So, in this article authors aim to solve the following problems: - to identify factors that affect the choice of a certain set of rationing rules for the limited stock; - to attempt to classify existing rationing principles; - to identify how the business goals affect the choice of the preferred rationing principle; - to create an imitation model and check experimentally which rationing principles are the best for each of the business goal The outcomes gained might be used as a base for the choice of the limited stock rationing principles in companies with own distribution network, and for better tuning of the distribution algorithms in DRP systems or modules.
Proceedings of the 32nd European Conference on Modelling and Simulation (ECMS 2018)
The article presents the results of the study of routing algorithms in ad hoc networks. Considered the scope of ad hoс networks. The problems that arise when trying to move to decentralized networks are shown. Briefly presented the existing types of content search routing algorithms. Considered the conditions necessary for their application. One of the existing algorithms is analyzed in detail using the model execution example. The presented algorithm is focused on the geographical position of the node in space. A brief description of the algorithm in pseudocode is also given. The written application allows the user to study the work of the decentralized network with the specified parameters. User can explore the network by getting an interactive display of the connections between the bonds and the paths of the constructed routes. Simulated in high-level Java programming language using Anylogic.
A form for an unbiased estimate of the coefficient of determination of a linear regression model is obtained. It is calculated by using a sample from a multivariate normal distribution. This estimate is proposed as an alternative criterion for a choice of regression factors.