On the Interoperability of DEVS components: On-Line vs. Off-Line Strategies

During the last years, the DEVS community provides many contributions towards the realization of a world-wide platform for collaborative Modeling & Simulation. The goal of such a platform would be to enable the sharing and reuse of models between scientists, as well as the seamless simulation of distributed and heterogeneous models. Therefore, one of the major research fields is the definition of architectures for integrating heterogeneous DEVS components, meaning simulators and/or models written in different frameworks and programming languages. In this work, we present three different strategies for providing such interoperability between DEVS components. The first focuses on standardizing exchanges between simulators, and has been explored in previous works. The two others strategies are more prospective; in keeping with Model-Driven Engineering, they place the model at the center of their architecture and make extensive use of model transformations. To make this possible, we defined a platform and language-independent format for describing and sharing DEVS models, called DEVS Markup Language

Importance of screening for urinary tract infection in African Black diabetics

Urinary tract infections are common and often latent in diabetic patients. The objective of this study was to determinethe frequency of urinary tract infections and the organisms responsible.This is a descriptive type prospective study conducted in the Endocrinology and Diabetology ward of Donka UniversityHospital. All diabetic patients hospitalised from January 3rd to April 4th 2013 were included in the study.Two hundred and sixty-two diabetics had been screened, 64 (24.42%) had a urinary tract infection 41 women (64%)and 23 men (36%). The average age was 56.48 16.3 years with a range of 20-90 years. Urinary tract infections weremore frequent between the ages of 45 and 74 (67.20%). Sixty patients were married, four were single. Fifty-six patientswere type 2 diabetes against eight type I diabetes. Urine test strips showed 60 cases of pyuria, 36 cases of nitruria, 21cases of proteinuria and three cases of hematuria. Organisms identified were: Escherichia coli in 31 cases (48.43%): 25women and six men; Klebsiella pneumoniae in 14 cases (21.87%): nine women and five men; Staphylococcus aureusin 11 cases (17.18%): six women and five men; and Proteus mirabilis in eight cases (12.51%): two women and six men.The clinical manifestations were: asymptomatic bacteriuria in 57 cases (89.06%); acute cystitis in five cases (7.81%); andacute urethritis in two cases (3.13%).Urinary infection in African diabetics is very common. It requires a systematic screening with urine test strips becauseasymptomatic types are by far the most common. This would allow early treatment and avoid serious complications

Verification and Validation of D2FD Method

International audience—D2FD (Data to Fuzzy-DEVS) method provides a solution for the problem of system inference. This method is well designed and implemented as an available and dedicated plug-in within the process mining framework (ProM). This plug-in is also integrated with the simulation tool SimStudio. However, the last step of the process of inferring models and simulations, which is verification and validation, is missing. This paper proposes a new paradigm of verification and validation in system inference. The case study uses the method of comparing with other models as the main validation technique. Based on the same data source from the Dutch Employee Insurance Agency, it attempts to compare the previous results with other studies

Digital Twin for Smart Cities: An Enabler for Large-Scale Enterprise Interoperability

In a context of increasingly connected production systems and ambient intelligence, the digital twin is an approach that is becoming increasingly popular to help control and pilot such systems. The interest for the digital twin is to be able to meet a need for modeling and piloting as close as possible to the physical system and a better anticipation of behavior. How, in this context, the question of the composition of digital twins to model a system of systems, where each system already has its own digital twin? This paper examines such a question from the perspective of digital twin for smart cities. The position adopted here is the concept of Digital Industrial Territories, a middleware for large scale interoperability between digital twins of enterprises involved in multiple supply chains (energy, transport, health, etc.). © 2022 CEUR-WS. All rights reserved

A Simulation Based Approach to Digital Twin’s Interoperability Verification & Validation

The digital twins of production systems are one of the pillars of the Indus-try of the Future. Despite numerous on-going research and development initiatives the verification and validation of the digital twin remains a major scientific obstacle. This work proposes a simulation-based approach to achieve this goal: support Digital Twin verification and validation through the definition of a dedicated framework. A simulation model is used in place of the real-world system for ensuring the digital twin behaves as expected and for assessing its proper interoperability with the system to be twinned with. Then the simulation model is replaced by the real-world sys-tem, to interoperate with the verified and validated digital twin. With such an approach, the interoperability middleware, i.e. the IoT between the sys-tem and its digital twin can also be modeled, simulated, verified and vali-dated. Consequently, an optimized solution can be built for an entire value chain, from the system to its digital twin and conversely. © 2022 CEUR-WS. All rights reserved

IJMSSC

DEVS is a sound Modeling and Simulation (M&S) framework that describes a model in a modular and hierarchical way. It comes along with an abstract simulation algorithm which defines its operational semantics. Many variants of such an algorithm have been proposed by DEVS researchers. Yet, the proper interpretation and analysis of the computational complexity of such approaches have not been systematically addressed and defined. As systems become larger and more complex, the efficiency of the DEVS simulation algorithms in terms of time complexity measure becomes a major issue. Therefore, it is necessary to devise a method for computing this complexity. This paper proposes a generic method to address such an issue, taking advantage of the recursion embedded in the triggered-by-message principle of the DEVS simulation protocol. The applicability of the method is shown through the complexity analysis of various DEVS simulation algorithms

Kidney failure screening in the general population of rural Africa

Kidney failure is a silently progressive disease too often unknown to the patients. The objective of this study was to assess the impact of kidney disease in Conakry so as to develop strategies for early detection and prevention.This was a descriptive-type prospective study carried out over six months, from January 31 to July 31, 2012. The study was carried out in two areas: In health facilities where the population were at a higher risk of developing kidney disease (diabetes, uropathies, infectious diseases and HIV, hypertension and cardiovascular disease), and in an apparently healthy population. In the study we included black subjects hospitalised in different targeted wards, as well as fully active apparently healthy subjects of the general population. Renal function was assessed with the simplified MDRD formula. Data collection included clinical parameters: Blood pressure, weight, height and blood laboratory parameters (creatinine, glucose) and urine (urine dipstick, 24h quantitative proteinuria).One hundred and ninety-nine patients were selected for the study: 117 men and 82 women ageing from 20 to 90 years. The prevalence of renal failure was 59% in the population at risk, with 53.3% of men and 16% in apparently healthy population with 60% of men with a statistically significant difference: p = 0.00000001. Proteinuria was observed in 86 patients in the population at risk against 19 in the healthy population

Activity Regions for the Specication of Discrete Event Systems

International audienceThe common view on modeling and simulation of dynamic systems is to focus on the specification of the state of the system and its transition function. Although some interesting challenges remain to efficiently and elegantly support this view, we consider in this paper that this problem is solved. Instead, we propose here to focus on a new point of view on dynamic system specifications: the activity exhibited by their discrete event simulation. We believe that such a viewpoint introduces a new way for analyzing, modeling and simulating systems. We first start with the definition of the key notion of activity for the specification of a specific class of dynamic system, namely discrete event systems. Then, we refine this notion to characterize activity regions in time, in space, in states and in hierarchical component-based models. Examples are given to illustrate and stress the importance of this notion

Hydatidose cérébrale multiple d’origine cardiaque: à propos d’un cas

L'hydatidose cérébrale est très rare, de bon pronostic après le traitement chirurgical. La forme multiple de l'hydatidose cérébrale rend difficile la prise en charge chirurgicale et altère le bon pronostic de cette  pathologie. Nous rapportons l'observation d'une hydatidose cérébrale multiple d'origine cardiaque chez une fillette de 06 ans amenée aux urgences pour crises convulsives généralisées et un syndrome d'hypertension intracrânienne. L'examen clinique était normal, la tomodensitométrie a révélé 8 kystes hydatiques cérébraux se situant à la fois en sus et sous tentoriel et des deux côtés de la faux du cerveau. Elle fut opérée en deux temps avec une bonne amélioration clinique. Nous soulignons à travers ce cas, la rareté et la difficulté de la prise en charge chirurgicale de l'hydatidose cérébrale multipleKey words: Hydatidose, cérébrale, cardiaqu

Geochemical composition of fluvial sediments in the Milo River basin (Guinea): is there any impact of artisanal mining and of a big African city, Kankan?

For the first time, the bed sediments of the Milo River and its tributaries were sampled and analyzed to characterize their geochemical signature in terms of major, trace and rare earth elements and to determine the potential impacts of artisanal mining and of the anthropogenic activities of Kankan city. 24 sites have been sampled along the Milo river from upstream to downstream and on its tributaries during one sampling campaign to assess the spatial variations of the geochemical signature. During one year, the bed sediments have been sampled monthly on the Milo river upstream and downstream Kankan to determine the seasonal variations of their chemical composition and to investigate the potential impacts of Kankan on the fluvial sediment quality. The geochemical signatures of the sediments are mainly controlled by the geological substratum and the lateritic soil cover, showing that there is no impact of the artisanal mining and very few impacts of Kankan, except for As and Sb on two small tributaries draining the urban agglomeration. All the sediments are more concentrated and naturally enriched in Zr, Hf, U and Th compared to PAAS, due to the regional geochemical background. REE distribution patterns show LREE and HREE enrichments and positive Ce and Eu anomalies. The La/Yb ratios are positively correlated to Al and Fe-oxides and negatively to silica. The non-residual fractions (labile) extracted with EDTA represent less than 20% of the total concentration, showing that the threats for aquatic ecosystems and human populations are limited. This study can represent a reference with regard to the potential development of industrial mining and increase of population due the abundant mineral resources within this catchment