Explicit parallel co-simulation approach: analysis and improved coupling method based on H-infinity synthesis

Co-simulation is widely used in the industry for the simulation of multidomain systems. Because the coupling variables cannot be communicated continuously, the co-simulation results can be unstable and inaccurate, especially when an explicit parallel approach is applied. To address this issue, new coupling methods to improve the stability and accuracy have been developed in recent years. However, the assessment of their performance is sometimes not straightforward or is even impossible owing to the case-dependent effect. The selection of the coupling method and its tuning cannot be performed before running the co-simulation, especially with a time-varying system.In this work, the co-simulation system is analyzed in the frequency domain as a sampled-data interconnection. Then a new coupling method based on the H-infinity synthesis is developed. The method intends to reconstruct the coupling variable by adding a compensator and smoother at the interface and to minimize the error from the sample-hold process. A convergence analysis in the frequency domain shows that the coupling error can be reduced in a wide frequency range, which implies good robustness. The new method is verified using two co-simulation cases. The first case is a dual mass–spring–damper system with random parameters and the second case is a co-simulation of a multibody dynamic (MBD) vehicle model and an electric power-assisted steering (EPAS) system model. Experimental results show that the method can improve the stability and accuracy, which enables a larger communication step to speed up the explicit parallel co-simulation.

Linguistic and didactic aspects of the “linguistic consciousness” formation in teaching foreign languages: grammar skills formation

The process of learning grammar is quite time-consuming. Poor grammar is often the reason that prevents people from communicating freely and competently in a foreign language. Definitely, some textbooks offer a sufficient number of grammar exercises, but, as a rule, these exercises are not aimed at communication. Therefore, it is quite natural that at the beginning of the formation of grammar skills, students do not have sufficient linguistic competence and psychological readiness for full-fledged foreign language communication. Consequently, the task of teachers is to create such conditions in the educational process where students are involved in communication step by step, with a gradual increase in psychological stress and linguistic load, at the same time including grammar tasks in the learning process. Thus, the relevance of this article is determined by the increased requirements for the quality of teaching a foreign language with a view to earlier communication and the undeveloped issues related to the problem of developing and improving grammatical skills.

An automated methodology to select functional co-simulation configurations

The development of machinery often requires system-level analysis, in which non-mechanical subsystems, such as hydraulics, need to be considered. Co-simulation allows analysts to divide a problem into subsystems and use tailored software solutions to deal individually with their respective dynamics. On the other hand, these subsystems must be coupled at particular instants in time, called communication points, through the exchange of coupling variables. Between communication points, each subsystem solver carries out the integration of its states without interacting with its environment. This may cause the integration to become unstable, especially when non-iterative co-simulation is used. The co-simulation configuration, i.e., the parameters and simulation options selected by the analyst, such as the way to handle the coupling variables or the choice of subsystem solvers, is often a critical factor regarding co-simulation stability. In practice it is difficult to anticipate which selection is the most appropriate for a particular problem, especially if some inputs come from external sources, such as human operators, and cannot be determined beforehand. We put forward a methodology to automatically determine a stable and computationally efficient configuration for Jacobi-scheme co-simulation. The method uses energy residuals to gain insight into co-simulation stability. The relation between energy residual and communication step-size is exploited to monitor co-simulation accuracy during a series of tests in which the external inputs are replaced with predetermined input functions. The method was tested with hydraulically actuated mechanical examples. Results indicate that the proposed method can be used to find stable and accurate configurations for co-simulation applications.

Analisis Semiotik PidatoPelantikan GubernurDKI Jakarta Anies Baswedan

First speech as governor DKI Jakarta was did by Anies Baswedan political communication step to consolidate Jakarta society after DKI Jakarta election. Phrasing content and choosing diction was important things in the formal speech. Phrasing pribumi word was forbidden by law to use, this make blunder for Anies team after contestation with incumbent rival the governor before who was lose, and this make pro and contra in DKI Jakarta society. This research was talked about semiotic analysis using triangle meaning theory Charles Sander Pierce for critic and interpretation descriptify speech governor DKI Jakarta Anies Baswedan content with “pribumi” word was made pro and contra in society life. Anies figure was knowed as an academic who achieved in country and international also served in some strategys position, considered not conscientious phrasing legal speech content ideal was mastered goodly by Anis Baswedan who did good legal speech even without teks. So make some question for researcher how actually content and situation was did speech by Anies. The interpretation of the use of the native word as a sign gives a negative image because it legally violates the president's instructions. But the use of the native word interpreted as an emergency word delivered by Anis represents a sense of injustice experienced by most of the Jakarta community in the context of his speech. This is an indicator that the majority of the people feel the injustice of their rivals whose note is the previous incumbent.

Communication for end-of-life care planning among Korean patients with terminal cancer: A context-oriented model

ABSTRACTObjective:In Korea, patients with terminal cancer are often caught out of the loop in end-of-life (EoL) care discussions. Healthcare professionals also have difficulty engaging in such communication in a variety of healthcare contexts. Therefore, the objective of our study was to develop a communication model for EoL care decision making compatible with the clinical environment in Korea.Methods:Using focus-group interview methodology, participants included eight doctors and five nurses who provide EoL care for terminal cancer patients in acute hospital settings or hospice care facilities in various provinces of Korea.Results:Five themes emerged regarding EoL care discussion, which included: (1) timing, (2) responsible professionals, (3) disclosure of bad news, (4) content areas of EoL care discussion, and (5) implementing strategies for EoL care discussions. These themes were based on development of a communication algorithm for EoL discussion among patients with terminal cancer. A structural communication step for delivery of a terminal prognosis was specified at the phase of disclosure of bad news: beginning with determination of a patient's decision-making capability, followed by a patient's perception of his/her condition, a patient's wish to know, family dynamics, and a patient's and/or family's readiness for EoL discussions.Significance of Results:The proposed context-oriented communication algorithm could provide a helpful guideline for EoL communication and, accordingly, facilitate meaningful improvements in EoL care in Korean clinical practice. The feasibility of this algorithm has not yet been determined, and its validation in a larger sample of patients with terminal cancers, using a quantitative research methodology, is a priority of research.

Fast Paxos Made Easy

Distributed consensus is one of the most important building blocks for distributed systems. Fast Paxos is one of the latest variants of the Paxos algorithm for distributed consensus. Fast Paxos allows an acceptor to cast a vote for a value of its choice unilaterally in a fast round, thereby eliminating a communication step for reaching consensus. As a tradeoff, the coordinator must build a quorum that is bigger than the simple majority used in Classic Paxos. This article presents the theory, implementation, and a comprehensive performance evaluation of the Fast Paxos algorithm. The theory is described in an easier-to-understand way compared with the original article by Lamport. In particular, an easy-to-implement value selection rule for the coordinator is derived. In the implementation of Fast Paxos for state-machine replication, a number of additional mechanisms are developed to cope with practical scenarios. Furthermore, the experiments reveal that Fast Paxos is most appropriate for use in a single-client configuration. The presence of two or more concurrent clients even in a local area network would incur frequent collisions, which would reduce the system throughput and increase the mean response time as experienced by clients. Due to frequent collisions, Fast Paxos actually performs worse than Classic Paxos in the presence of moderate to large number of concurrent clients.

Competition, Oligopoly, Barriers and Searching Up New Markets

This paper deals with the mobile technology as a new competitor in some hitherto quite closed markets. Particularly, digital photo camera market was until now widely focused into a few multinational firms, operating in international oligopolistic markets. The mobile smartphones technology leads to use the same device for quite different issues. The smartphones technology allows to use the same device for quite different issues. Although the purpose of most consumers when buying this kind of articles, is to use it for its main use, that is to say, for voice communication, step by step new applications and uses are being discovered as very useful. Even when mobile phone devices are not so good as the original devices for a particular use, they have a very important advantage: all in one, it means that if consumers are able to have several different uses with the same device, they probably choose this option than the “best quality” one provided for a lot of different devices, with much better results, because those better results are inevitably linked to the need of bearing several devices, which is not very comfortable. Moreover the “just in time” or “in situ” needs, can be covered for some devices which are not always in the hands of users. Then a new branch of competition linked more to immediacy than to the quality arises, particularly for youngest. This paper provides a theoretical based survey on market and competition theory, to understand some key points for explaining the smartphones success as a competitor in digital camera market. Results have shown that mobile cameras not only have started to compete with digital cameras unexpectedly, breaking established barriers in traditional oligopolies, but also they are one step ahead.

Error Analysis and Error Estimates for Co-Simulation in FMI for Model Exchange and Co-Simulation V2.0

Complex multi-disciplinary models in system dynamics are typically composed of subsystems. This modular structure of the model reflects the modular structure of complex engineering systems. In industrial applications, the individual subsystems are often modelled separately in different mono-disciplinary simulation tools. The Functional Mock-Up Interface (FMI) provides an interface standard for coupling physical models from different domains and addresses problems like export and import of model components in industrial simulation tools (FMI for Model Exchange) and the standardization of co-simulation interfaces in nonlinear system dynamics (FMI for Co-Simulation), see [10]. The renewed interest in algorithmic and numerical aspects of co-simulation inspired some new investigations on error estimation and stabilization techniques in FMI for Model Exchange and Co-Simulation v2.0 compatible co-simulation environments. In the present paper, we focus on reliable error estimation for communication step size control in this framework.