322 research outputs found
Branching Bisimilarity with Explicit Divergence
We consider the relational characterisation of branching bisimilarity with
explicit divergence. We prove that it is an equivalence and that it coincides
with the original definition of branching bisimilarity with explicit divergence
in terms of coloured traces. We also establish a correspondence with several
variants of an action-based modal logic with until- and divergence modalities
“Quia Similia Similibus Applaudant”: Visual Variations of Genesis 3 in the Medieval Mind
In Medieval Europe, the Bible was strictly prohibited in any language other than Latin. This prohibition of vernacular scripture led to other devotional mediums that drew from Biblical stories such as the book of hours, hagiographies, and paraphrases. In the latter half of the 12th-century, a French theologian by the name of Peter Comestor finished his biblical paraphrase Historia Scholastica. Due to Historia’s comprehensiveness, it became widely circulated and recognized as university required reading. When writing on Genesis 3, (the temptation, creation of sin, and expulsion from paradise) Comestor popularized the belief that to better ensure success the devil took the form of a serpent with the head of a woman to tempt Eve. This study aims to answer questions surrounding the medieval iconographic trend of depicting the serpent in Genesis 3 with the head, or full torso, of a woman. Mainly focusing on the stylistic variants of the woman-headed serpent such as wardrobe, hairstyle, or how much or how little the serpent resembled Eve. By analyzing the societal impact of the variants as well as the opposing venerated view of other Biblical women during the medieval age I intend to better understand the views of women’s culpability for sin and misogynistic allegations against women based in medieval popular circulating opinions on Genesis 3
Model and tool requirements for co-simulation of building performance
The use of building performance simulation (BPS) can substantially help in improving building design towards higher occupant comfort and lower fuel consumption, while reducing emission of greenhouse gasses. Unfortunately, current BPS tools do not allow inter-tool communication and thus limit a modeler to the component models available in the simulation software which happens to be used. A pragmatic way forward would be to enable cosimulation by externally coupled (legacy) tools. This means that each coupled software would represent only that part of the overall building and system configuration that it is able to model. The overall system is represented by the coupled models, which exchange simulation data during run-time. In this way, shortcomings of each tool can be overcome, and advantages of individual tools can be exploited. The work underlying this paper addresses co-simulation of building energy and heating, ventilation and airconditioning (HVAC) models. So far, the research focus has been on thermodynamic issues such as which variables should be exchanged and at what frequency, rather than on mathematic or computer science aspects. This paper specifies and discusses the requirements for BPS software in order to enable co-simulation of building and HVAC system configurations
HVAC system simulation: overview, issues and some solutions
Integrated performance simulation of buildings’ heating, ventilation and air-conditioning (HVAC) systems can help in reducing energy consumption and increasing occupant comfort. Recognizing this fact, in the last forty years many tools have been developed to help achieving this goal. In this paper we introduce a categorization of these tools with respect to which problems they are meant to deal with and summarize current approaches used for modelling (i) HVAC components, (ii) HVAC control and (iii) HVAC systems in general. Further in this paper, we list issues associated with applications of HVAC modelling and simulation. Finally, we present and discuss co-simulation as one of solutions that can alleviate some of the recognized issues
Case studies of co-simulation for building performance prediction
This paper aims to illustrate the usability and benefits of recent developments in co-simulation of building systems by means of several case studies. Co-simulation enables the reuse of models developed in separate simulation tools as well as integration of generic solvers into the computational building performance simulation domain. This in turn facilitates rapid prototype modeling of new and emerging building systems, and thus early performance prediction of innovative systems and concepts, which would not be feasible otherwise
Distributed simulation of building systems for legacy software reuse
The use of integrated building performance simulation can substantially help in improving a building design with regards to comfort levels and fuel consumption, while reducing emission of greenhouse gasses. However, the traditional tools that are closed for inter-communication, limit the modeler to use of components only available within that particular package. This paper gives an overview of distributed simulation approach that can alleviate above limitation. Each program can represent only a part of a building system that is able to model, exchanging the necessary information during the execution and bridging the gaps between the tools. Several important issues closely connected with its implementation, such as synchronization, are pointed out, and the sensitivity of a model on different coupling strategies is studied. The paper concludes with highlighting the gained flexibility in modeling and simulation of building performance that arises from the distributed approach
Building energy simulation and optimization of industrial halls
Industrial halls are characterized with their rectangular shape and relatively simple construction, as contrasted with office buildings with similar floor area. Industrial halls are usually subject to high energy demand due to the many manufacturing processes, lighting, and the corresponding amount spent on space conditioning. Thermal comfort is seldom a concern for industrial halls. By contrast, saving in energy consumption for lighting and space conditioning is a big issue since even the modest percentage change in energy consumption could be translated into a large monetary sum. With relatively loose requirement in space conditioning, and comparatively high internal heat gain; the approach in industrial hall design is quite different from that of office building. In fact, what poses to be an energy efficient design for office buildings might not be appropriate for high internal heat gain halls. The simplicity in the building geometry and the construction method allow the investigation of energy demand for space conditioning to be limited to a few number of demand side parameters (e.g. insulation value of walls); in which, change in values in some of the parameters presents a significant impact on the overall energy demand. This paper investigates the impact of varying different demand side parameters on the energy demand for space conditioning and lighting for a typical industrial hall. Through building energy simulation, such impact can be investigated; and by applying optimization, the configurations of the most optimal combinations of parameters with the lowest energy demand can be identified. The result indicates that the energy demand of the least efficient configuration can be more than double of that of the optimized design solution. This paper will also explore green building assessment systems such as LEED, in terms of energy performance, with the studied industrial hall as an example. The huge energy saving brought by the optimized design solution over the baseline building of LEED suggests that there might be a potential deficiency of LEED rating system at its current state as it applies to industrial halls
Comparison of co-simulation approaches for building and HVAC/R system simulation
Appraisal of modern performance-based energy codes, as well as heating, ventilation, airconditioning and refrigeration (HVAC/R) system design require use of an integrated building and system performance simulation program. However, the required scope of the modeling library of such integrated tools often goes beyond those offered in available simulation programs. One remedy for this situation would be to develop the required models in an existing simulation program. However, due to the lack of model interoperability, the model would not be available in other simulation programs. We suggest co-simulation for HVAC/R system simulation as an approach to alleviate the above issues. In co-simulation, each subsystem is modeled and simulated in the appropriate simulation program, potentially on different computers, and intermediate results are communicated over the network during execution time. We discuss different co-simulation approaches and give insights into specific prototypes. Based on the prototypes, we compare the approaches in terms of accuracy, stability and execution time, using a simple case study. We finish with results discussions and recommendations on how to perform co-simulation to maintain the required accuracy of simulation results
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