Modeliranje sistemov paralelne strežbe v GPSS-u

This article treats parallel service system modelling in the GPSS simulation language. The transactions entering such systems select between numerous different servers and we can mostly detect two rules in the selecting of the appropriate server. The first rule always gives the first few (regarding its position in the system) entities (either servers or queues) precedence over the others, while the second rule always treats all the equal entities evenly and selects among them quite randomly. Since GPSS normally operates by the first rule, we frequently come up against difficulties when modelling systems that serve by another rule. The present article offers a methodology how to solve this problem within GPSS.Članek obravnava modeliranje paralelnih strežnih sistemov v simulacijskem jeziku GPSS. Transakcije, ki vstopajo v takšne sisteme, izbirajo med večjim številom strežnih mest. Pri zasedanju teh mest pa lahko v grobem zasledimo dva različna pravila. Prvo pravilo daje prednost zasedanju prvih (po svoji poziciji v sistemu) entitet (bodisi strežnikov, bodisi čakalnih vrst), medtem ko drugo pravilo obravnava te entitete enakovredno in izbira med njimi povsem naključno. Ker GPSS v svojem delovanju privzema prvo pravilo, lahko pri modeliranju sistemov, ki strežejo po drugem pravilu, pogosto naletimo na določene težave. Pričujoči prispevek ponuja metodologijo, kako znotraj tega jezika reševati omenjeni problem

Tunnel information modelling in most recent form: applying BIM technologies and procedures in tunnelling environment

The importance of information management was recognised in surface construction industry decades ago, and has increasingly being recognised through formal process and laws. Around the world, these laws and codes of practice are currently being drafted and enacted, to reflect the development of software tools and corresponding increasing adoption by industry. This paper deals with specifics of implementing information modelling in tunnelling business utilising BIM (Building Information Modelling) technology developed for buildings as well as similar technology developed for mining industry. Although BIM is recognized initially as a 3D digital representation of physical and functional characteristics of a facility, the real benefits come when complex capability through construction sequencing and even detailed programming (4D) and cost capabilities (5D) are included

Development of a Semiautomatic Parametric Method for Creation of an I-BIM Model of a Tunnel for Use in FEM Software

This paper focuses on the design phase of I-BIM tunnelling projects using Sequential Excavation Method (SEM), in Europe, commonly referred to as the New Austrian Tunnelling Method (NATM), and addresses the problem of coupling geotechnical conditions and tunnelling Building Information Model (BIM) for the preparation of the computational model suitable for the finite element analysis method (FEM). The review of the literature led to the conclusion that an automatic merging of the tunnel model and ground model for use in the FEM software is currently not reliable due to the number of differences between various types of models as they serve contrasting needs. Consequently, modelling becomes a manual task, which is very time-consuming and error prone. In this paper, we present the development of a framework for the semiautomatic transformation of the various tunnelling models and respective ground models into the model suitable for further analysis. We conclude that the import and translation of the geometry into the FEM software are most successful and accurate when the initial I- BIM (tunnel) model is prepared at a level of detail appropriate for a computational model. The result is the I-BIM model, fit for use in the FEM software which speeds up the modelling process and reduces errors. We have shown that it is possible to prepare the geometry of a tunnel in the BIM software, transfer it, and use it in the software for geotechnical analysis. This makes the preparation of the tunnel geometry for FEM analysis much easier and faster. Due to the fast preparation of the geometry of the new model, the approach presented in this research is useful in practice. The applicability of the framework and the framework workflow are both presented through a practical case study