Shape Grammars for Architectural Heritage

Shape grammars have been introduced in architectural theory some decades ago. They have been applied to architectural construction methods (e.g. Chinese traditional wooden buildings) or for analyzing the design patterns of well-known architects (e.g. Palladio, Frank Lloyd-Wright).These examples demonstrated that complex geometrical shapes could be generated by a set of replacement rules out of a start symbol, usually a simple geometric shape. With the advent of powerful tools like the CityEngine an interesting field for practical applications of these grammars arose opening a whole range of new possibilities for architectural heritage.On the one hand, a description of ancient building principles in the formalized way of a shape grammar can aid the understanding and preservation of cultural heritage. With the possibility to actually construct digital 3D models out of shape grammars, they became even more interesting. Furthermore, this approach allows for a large scale creation of 3D models of entire settlements and cities.On the other hand, shape grammars allow for structured approaches to virtual 3D reconstruction as has been demonstrated for e.g. Mayan or Roman architecture. Besides that, the possibility to specify parameterized variations of the models proves to be an extremely helpful feature.In this paper we reconsider shape grammars in architecture and examine influences onto procedural modelling. Then we argue for state-of-the-art tools like the CityEngine that apply shape grammars and procedural modelling in architectural contexts and exemplify their power and potential by reconstructing traditional Balinese settlements

A THEORETICAL MODEL FOR THE SHOULDER GIRDLE APPLICATIONS IN SPORT

The shoulder system is one of the most solicited in the human body due both to its large range of mobility and to the magnitude of forces which are acting over. Only to give an example, using a confirmed finite element model for the shoulder girdle (Pronk, 1990; van der Helm, 1992) during unloaded abduction-adduction movement the maximum force in the glenohumeral joint is about 400 N (!), increasing to about 1,100 N in the 10 kg loaded abduction-adduction. According to our knowledge in the literature exists a lack concerning theoretical models for this system and the existing ones are not able to explain the complete range of motion. In the same time, our experience in working with high-performance athletes, told us that many injuries appear in this joint, most of them in throwing events. In our paper we try to present an analytical model for the shoulder girdle and to predict the force distribution over the mechanism for javelin throw. The technique of a group of 6 high-performance athletes, was analyzed using common video methods and non-professional equipment. The trajectories of the collected points on video tapes are analyzed using classic interpolation methods and prepared for model input. In the present model we have eliminated the hypothesis of closed-chain mechanism and we have replaced the multi degrees of freedom joints by collection of one degree of freedom joints using the Gruebler-Harisberger equivalence theorem. The weakest point of this model is to specify the muscle forces and to introduce them in the model. After that it was followed the classic method for positional, kinematic and dynamic analyzes, using a matrix method based on Denavit-Hartenberg matrix representation. The comparison between these two methods- theoretical and collected on videa tapehas provided good results for position and kinematic analyzes, but not reliable for dynamic analyzes. The advantage of such model could be that in this way it is possible to simulate all types of movements and it is possible to predict the sportive behavior to abnormal solicitations

Dynamic shading systems: A review of design parameters, platforms and evaluation strategies

The advancements in software and hardware technologies provide opportunities for solar shading systems to function dynamically within their context. This development has helped dynamic shading systems respond to variable environmental parameters such as sun angles and solar insolation. However, the technical understanding of system design, mechanism and controlling methods presents a challenge for architects and designers. Therefore, this study aims to review the current applications and trends of dynamic shading systems to clarify the potentials and limitations in enhancing system performance based on integrated design objectives. This study assessed several systems on the basis of a critical review to identify different models, applications and methodologies. This study is divided into two main sections: (i) design elements and platforms that engage with specific methods in creating a dynamic shading system and (ii) evaluation strategies to examine system performance. The systems were investigated based on the multiplicity and integration of the parameters involved through various components, such as architectural, mechanical, operational and automation components. The review analysed various studies on the following two bases: (1) geometric-based analysis, which distinguishes between simple and complex shading models, and (2) performance-based analysis, which assesses the shading systems based on two groups of methodologies, namely, theoretical and experimental. The outcome of the review reflects a clear classification of shading models and a comprehensive analysis of their performance. This study generally provides a systematic framework for architects based on thorough research and investigation. Finally, the study introduced several findings and recommendations to improve the performance of dynamic shading systems

A comparative review of tone-mapping algorithms for high dynamic range video

Tone-mapping constitutes a key component within the field of high dynamic range (HDR) imaging. Its importance is manifested in the vast amount of tone-mapping methods that can be found in the literature, which are the result of an active development in the area for more than two decades. Although these can accommodate most requirements for display of HDR images, new challenges arose with the advent of HDR video, calling for additional considerations in the design of tone-mapping operators (TMOs). Today, a range of TMOs exist that do support video material. We are now reaching a point where most camera captured HDR videos can be prepared in high quality without visible artifacts, for the constraints of a standard display device. In this report, we set out to summarize and categorize the research in tone-mapping as of today, distilling the most important trends and characteristics of the tone reproduction pipeline. While this gives a wide overview over the area, we then specifically focus on tone-mapping of HDR video and the problems this medium entails. First, we formulate the major challenges a video TMO needs to address. Then, we provide a description and categorization of each of the existing video TMOs. Finally, by constructing a set of quantitative measures, we evaluate the performance of a number of the operators, in order to give a hint on which can be expected to render the least amount of artifacts. This serves as a comprehensive reference, categorization and comparative assessment of the state-of-the-art in tone-mapping for HDR video.This project was funded by the Swedish Foundation for Strategic Research (SSF) through grant IIS11-0081, Linköping University Center for Industrial Information Technology (CENIIT), the Swedish Research Council through the Linnaeus Environment CADICS

Perception based illustration methods

This paper describes some visual phenomena of human perception in the context of computer based Illustration. Some of these phenomena of the human visual system will be used to introduce an illustrative rendering style for three-dimensional line drawings with enhanced depth cuing to visualize spatial properties of three-dimensional objects. The additional purpose of this paper is to inspire the study of human perception more deeply to derive new non-photorealistic rendering methods that can enhance the visualization of complex spatial concepts and its three-dimensional characteristics

Cubic Monte Carlo Radiosity

A revised radiosity method for curved surfaces is proposed, based on the Monte Carlo approach. In order to improve the accuracy of the solution, a smoothly reconstructed illumination function with selected discontinuities is used during the radiosity computation. The reconstructed function is used as a random number distribution for position sampling to overcome the constant radiosity assumption syndrome. Illumination information stored at the surface control points is used to preserve continuity of the illumination across the boundary of adjacent surfaces and to avoid Mach band effects. Implementation in Flatland is discussed

Framework for the assessment of the existing building stock through BIM and GIS

With 60% of the world's raw materials extraction, the construction sector is the largest consumer of raw materials. The consumption can be reduced through reuse and recycling of building materials which reached their end-of-life; however, there is lack of information on the building stock. This paper presents a bottom-up approach based on Building Information Modeling (BIM) and Geographic Information System (GIS) to assess material quantities. To test this approach, a real-world building is used. The material intensity is calculated based on existing planning documentations, on-site investigations, laser scanning and a BIM-model. The gross volumes (GVs) obtained from GIS enable the modelling and prediction of cities' building stocks. The results of this paper demonstrate the method of calculating material intensities and present how the applied method can be used to predict building stocks. The latter is presented as a framework which can support various cities in assessing their material stock