Pre-design Stage Research Articles

Investigation of Airflow for Natural Ventilation in the Typical Medium-Rise Housing Cluster in South-Eastern Nigeria

Wind driven natural ventilation dependents on the microclimate conditions of its environment to thrive. In urban streets, it is influenced by the wind velocity and air temperatures factors. In this study, field experiments were carried out in selected streets of a typical medium rise housing cluster in southeastern Nigeria. The aim of the study was to understand the characteristics of air flow within this housing category, and to better examine the potentials of wind driven ventilation in this class of settlement. Wind speed and directions in the middle of selected streets were measured. Respectively, the undisturbed climatic conditions above the street canyon were recorded as well. The overall conclusion at the end of the study is that inside the streets, the potential of natural ventilation for both the single type and multi-branch type configurations is reduced, while that of continuous street configuration (without intermediate intersections) provided a higher potential for natural wind driven ventilation. This is attributed to the internal interferences and reduction of the wind speeds inside the street canyons. Generally, universal meteorological information gotten from unobstructed areas in cities are used in the design of buildings, thus the significance of this study outlines the importance of obtaining microclimatic information in pre-design stages.

Artificial neural network response assessment of a single footing on soft soil reinforced by rigid inclusions

This study is devoted to investigate the behavior of a single footing resting on a soft soil reinforced by four rigid inclusions (RI) using an Artificial Neural Network (ANN). Full-scale static loading tests on a single footing are considered as the reference of this study. For the design of such structures, a geotechnical investigation allowed the soil properties determination. Then 3D Finite Difference Modeling (FDM) analyses were conducted and validated on the experimental results. A total of 196 datasets are used to construct and verify the Artificial Neural Network (ANN) response model accuracy. To follow the behavior of such footing, its center settlement, global load transfer efficiency and the maximum rigid inclusions bending moments are considered. This approach allows to efficiently assess the rigid-inclusion reinforced system performance with a high degree of success. Hence it is used to compute the RI-reinforced footing system responses under various configurations. A comparative study is carried out considering four key parameters of the load transfer platform. Four design charts are proposed and can serve for a pre-design stage.

Investigation of Rotational Magnetization Under Non-Sinusoidal Excitation for Non-Oriented Material

Rotational loss forms a significant portion of total core losses in electrical machines. The influence of harmonics on the behavior of magnetic materials is inevitable as these machines are mostly supplied by power electronic converters. Minor loops in hysteresis curves due to harmonics lead to additional losses. While the case of alternating induction (1-D magnetization) with harmonics is thoroughly considered in the literature, the assessment of the effect of rotational magnetization (2-D magnetization) has not yet been done adequately. A qualitative evaluation of rotational hysteresis loops in the presence of minor loops is carried out. The impact of minor loops in the evolution of hysteresis loops under rotating fields is examined. A peculiar behavior of interleaving of hysteresis loops under rotational magnetization is observed, which will affect the total core loss. This analysis can be used to visualize flux patterns on account of rotational magnetization and to accurately predict the performance of a machine during its predesign stage.

Virtual Reality for Learning.

The consumer age of the Personal Computer and mobile devices has opened up a new world of opportunities for innovative teaching methodologies, many based on serious games and virtual worlds. Similar levels of market penetration are expected for the use of Immersive Virtual Reality (iVR) over upcoming decades, once all the core technologies for game engines and head-mounted displays are available on the market at affordable prices. In this chapter, a general overview of the state of the art of iVR learning experiences is presented. Firstly, the advantages of iVR over traditional learning are described - advantages that must be considered when defining iVR experiences for the optimization of student learning and satisfaction. Secondly, the relationship between learning theories and iVR experiences is briefly summarized; an area where constructivist theories appear to be the most commonly used theory in iVR experiences. Thirdly, some examples of the success of iVR applications at different learning levels, from primary school to higher education, are summarized. Fourthly, the key factors for the successful design and use of an iVR experience in education are identified, from the predesign stage to the final evaluation - with special attention given to the different possibilities of each type of HMD for different kinds of educational experiences. Finally, the main limitations of iVR for learning today and the future trends of this technology for teaching are also identified and discussed.

A Simplified Methodology of European Steel Characterization on Theoretic Structural Application with Buckling Restrained Braces

The objective of this research is to provide simplified equations to fix the steel mechanical parameters when applied to all-steel buckling restrained braces (BRBs) whiting a whole theoretic structural calculation. These equations can be mainly useful in the predesign stage when the data of steel tests are still not available. A revision and search were carried out of available steel values from monotonic and cyclic uniaxial tests by different European steels. Curves of regression were fitted to find the necessary parameters for numeric models of BRBs with typical hysteretic dissipation. A comparison of results from applying three different groups of adopted steel values (nominal, regression or actual, and maximum) is done with a well-known and tested BRB. The high dispersion of results that arise is shown. The regression equations found demonstrate great usefulness. For an initial theoretic calculation, departing from most actual parameters of steel strongly decrease the uncertainty and it allows calculating structures with BRBs in a more realistic way.

The Influence of Social Information: A Study of Architectural Attribute from an Event Structure Analysis Perspective

Scientific and technological developments have led to gradual abstraction in architectural research and design. People no longer interpret spatial meaning simply through external forms, rather, the emphasis is put on the essence of design thinking. This change has given rise to analysis and expression methods at the level of the architectural attribute, which scientifically summarize the attributes shared by different architectural types through investigating the literature data and professional phenomena. They improve the architects’ level of awareness and provide a guiding framework for subsequent design work. However, rapid social progress and regional cultural differences make it difficult for previous methods to reflect the real-time and in-site expression of the attributes. This paper proposes a new attribute study approach based on Event Structure Analysis (ESA) in combination with social science theory. This approach provides architects with a reference for more comprehensive attribute expression by coordinating the social information at the pre-design stage. Meanwhile, with openness and operability as its technological advantages, it forms a cross-disciplinary research and exchange platform, thereby allowing public participation. The study verifies its feasibility through the structured analysis of specific social events in Beijing, discusses this interdisciplinary approach’s practical significance and positive impact at the professional and societal levels, and points out the direction for future research.

Performance prediction of centrifugal compressor based on a new volute loss model and corrected theoretical work

AbstractPerformance prediction plays an important role in the predesign stage of centrifugal compressors. A set of loss models is usually selected and grouped to fulfill the above prediction. To improve the defects of traditional prediction, we modified the outlet velocity and slip coefficient of the impeller by means of the energy average method to obtain theoretical work. A new volute loss model is proposed to replace the traditional semiempirical loss model by adopting a suitable loss model for each flow passage component. A proper performance prediction method is established for the centrifugal compressor studied in this paper. The overall performance of a single‐stage centrifugal compressor is predicted and compared with experimental and numerical simulation results. It is found that the prediction method proposed can better predict the overall performance of the centrifugal compressor. And the volute loss is the third largest loss after impeller loss.

Models of early stages of design of trunk-route passenger airplanes with taking families into account

There is a tight connection between the Pre-Design (development of requirements for the designed airplane) and Conceptual Design stages while creating a new aircraft. Taking this connection into account would result in the design of more optimal aircraft that would have the appropriate advantage during operation. Previously when the ability to take such interconnections into the account was lacking the designers were forced to allocate certain reserves in the project based on previous design experience. The advancement of design, modeling and manufacturing methods allowed transitioning from allocating these reserves as means for possible error compensation to their planning or management. In particular, such planned reserves should be allocated in wing and landing gear at the Conceptual Design stage for the creation of passenger airplane families. The values of these reserves should be substantiated based on the evaluation of future functioning of the whole created airplane family within the airline fleet. This requires solving a problem of Pre-Design and requirements creation. Thus, the reserves become new design variables. The values of these new variables should be optimized together with the values of the existing “traditional” variables during airplane design. A model, which takes management of the aforementioned reserves into the account during airplane design, was constructed. The presented model is intended for usage within the framework of the models, which solve the problem of creation of a passenger airplane fleet at Pre-Design stage with taking the presence of an airplane family within this fleet into the account as well as optimization of this passenger airplane family. The model calculation results were verified for the trunk-route passenger airplanes of all main types with taking the existence of the appropriate families into the account. During verification the wing of each considered passenger airplane was sized for the appropriate family version with the maximum take-off weight. After that this wing was “fixed” and processed as initial data for the family version, statistics on which was used for checking the model calculation results. The verification demonstrated good correlation between the model calculation results and the available statistics. It also showed that the presented model can be used for the design of individual trunk-route passenger airplanes and families of all main types (short-, medium- and long-range).

Multi-Objective Optimization of Building Environmental Performance: An Integrated Parametric Design Method Based on Machine Learning Approaches

Reducing energy consumption while providing a high-quality environment for building occupants has become an important target worthy of consideration in the pre-design stage. A reasonable design can achieve both better performance and energy conservation. Parametric design tools show potential to integrate performance simulation and control elements into the early design stage. The large number of design scheme iterations, however, increases the computational load and simulation time, hampering the search for optimized solutions. This paper proposes an integration of parametric design and optimization methods with performance simulation, machine learning, and algorithmic generation. Architectural schemes were modeled parametrically, and numerous iterations were generated systematically and imported into neural networks. Generative Adversarial Networks (GANs) were used to predict environmental performance based on the simulation results. Then, multi-object optimization can be achieved through the fast evolution of the genetic algorithm binding with the database. The test case used in this paper demonstrates that this approach can solve the optimization problem with less time and computational cost, and it provides architects with a fast and easily implemented tool to optimize design strategies based on specific environmental objectives.

Updates on CEA Design and Experimental Activities on EU DEMO TF System

In the framework of EU design activities for dimensioning the future fusion DEMOnstration reactor (DEMO), in-depth analyses were conducted in EUROfusion context, aiming to define the design of the DEMO magnets system. For the last DEMO baseline, CEA has proposed for Toroidal Field (TF) coils a concept with radial plates (named WP#4) which is ITER-like, with a round conductor embedded in steel plates. In order to consolidate this design, CEA conducted fine analyses that assess thermal hydraulic and mechanical aspects to allow ensuring compliance with design criteria. The outcomes of theses analyses were used to improve the TF design in order to avoid relying on conservative approaches at pre-design stage, which often end up in material over dimensioning, that penalize cost and space occupation. In this regard, two improving approaches will be exposed, that deal with mechanical consideration and temperature operation, together with future perspectives. On the other hand, CEA designed and manufactured in collaboration with ASIPP a full-size conductor sample derived from a previous TF CEA concept (square-in-square conductor) which is expected to operate at 88 kA and 12T. The two conductor legs of this sample were designed by CEA and manufactured by ASIPP following an extensive quality assurance (QA) preparation process. The sample is presently in course of assembly in CEA Cadarache and is expected to be tested in SULTAN facility (Villigen, CH) to assess its behaviour in both DC and AC regimes. An overview of the status of activities and future perspectives is given in this paper.

Analytical Iron Loss Evaluation in the Stator Yoke of Slotless Surface-Mounted PM Machines

One of the attractive benefits of slotless machines is low losses at high speeds, which could be emphasized by a careful stator core loss assessment, potentially available already at the predesign stage. Unfortunately, mainstream iron loss estimation methods are typically implemented in the finite element analysis environment with a constant coefficients dummy model, leading to weak extrapolations with huge errors. In this article, an analytical method for the iron loss prediction in the stator core of slotless PM machines is derived. It is based on the extension of the 2-D field solution over the entire machine geometry. Then, the analytical solution is combined with variable coefficient loss models (VARCO) or constant coefficient loss models, which can be efficiently computed by vectorized postprocessing. VARCO loss models are shown to be preferred at a general level. Moreover, this article proposes a lookup-table-based solution as an alternative approach. The main contribution lies in the numerical link between the analytical field solution and the iron loss estimate, with the aid of a code implementation of the proposed methodology. First, the models are compared against a sufficiently dense dataset available from laminations manufacturer for validation purposes. Then, all the methods are compared for the slotless machine case. Finally, the models are applied to a real case study and validated experimentally.

МЕТОДИКА ПОДБОРА АРХИТЕКТУРНОГО РЕШЕНИЯ ПРОЕКТИРУЕМОГО ОБЪЕКТА КАПИТАЛЬНОГО СТРОИТЕЛЬСТВА НА ПРЕДПРОЕКТНОЙ СТАДИИ

The development of science and technology in various areas of human life leads to the fact that an increasing number of routine operations are automated, which is the subject of many scientific works. At the same time, in the field of selecting an architectural solution for a projected capital construction object at the pre-design stage, such a problem has not yet been solved. The aim of the work is to develop a methodology to improve the efficiency of the architect when creating an architectural solution and choosing its location and orientation.

Pre-Design Stage Cost Estimation for Cloud Services

Pre-Design Stage Cost Estimation for Cloud Services

Opportunities to increase road reliability

The article discusses all the factors that should be paid attention to at the pre-design stage of design, the correct collection of this information allows you to effectively manage the design work. With proper coating, it will withstand many adverse conditions. Important factors are listed that sharply reduce the reliability of the road section, jeopardizing its stability and strength, and ways to eliminate the threats posed by these factors are presented.

Thin lens narcissus model in infrared lens design with cooled detectors.

A mathematical model of the narcissus effect in infrared lenses with cooled detectors is discussed. The proposed model enables optical designers to take the narcissus performance of infrared lenses into consideration in the thin lens predesign stage. Third order thin lens aberration theory is the basis for the newly proposed narcissus analysis. Two narcissus metrics are defined in terms of structural parameters of the infrared lens to be designed. The metrics provide an indirect way of controlling narcissus performance in thin lens predesign. A long wave infrared lens is discussed from a narcissus perspective within the proposed model as an example. It is shown that the proposed narcissus model is a very effective way of controlling narcissus performance, starting from the early stages of lens design.

ОЦІНКА ІНФОРМАЦІЙНОЇ ПОВ’ЯЗАНОСТІ ПРОЦЕСІВ ПРИ ФУНКЦІОНАЛЬНОМУ МОДЕЛЮВАННІ СИСТЕМИ ВИПРОБУВАНЬ

The national security and defense capability of the state is largely determined by the level of equipping the armed forces with modern weapons and military equipment. An important point in the rearmament of the army is the high-quality and timely testing of the latest military models, which, to a large extent, is ensured by successful and systematic planning and management of test activities. The automated test support information system is aimed at solving such problems. During the IDEF0 notation, functional modeling of the armaments and military equipment testing system was designed, which allowed to determine the system-wide characteristics of information flows, but did not allow obtaining models performance evaluation. Existing methods for estimating distributed structures, as a rule, are reduced to estimating the connectivity of graph models and do not take into account the features of the interface of the IDEF0 notation functions.The article considers the issue of evaluation of functional models at the pre-design stage. A method for estimating the functional connectivity of processes in the functional modeling of complex systems using graph-ical notation IDEF0 and using automated design tools is proposed. The estimation has clear logical limits and is sensitive to changes in the parameters of the evaluated model. Due to the different importance of connections provided by the graphical notation interface IDEF0, it is proposed to use a scale of importance of the type of connection, which reflects the assessment of the connectedness of functions of strong or weak types of connections, and, accordingly, the success and rationality of functional configuration models. Estimates of the functional model of the weapons and military equipment test system are obtained.The use of the proposed evaluation method will allow to compare the structures of functional models of complex systems at the stage of pre-design studies

PARAMETRIC SYNTHESIS OF THE ELECTRIC POWER FACILITY AS A TASK OF SEARCH OPTIMIZATION

The decision to choose the most acceptable alternative of the alternatives proposed by the contractor for the possible development of an engineering object at the pre-design stage of the life cycle of the object means an agreement between the customer and the contractor and the coordination of the technical characteristics and the indicators of the object declared for development corresponding to these characteristics. The specified characteristics and indicators are necessary conditions for the transition to the project stage and for many reasons should be considered as the most important, given the implementation of all subsequent stages of the life cycle of the declared engineering object. At the design stage of any engineering object, various studies are carried out in order to develop mathematical and, if necessary, material models and tools at different levels of integration of the object's components.The developed models become the basis for the implementation of the general process of parameters synthesis for specific components and objects, as well as for further technical support of the life cycle of engineering objects under development.The concept of solving the problem of parametric synthesis of the components of the designed engineering object is presented and is reduced to the necessary procedures for search optimization and provides for multiple numerical implementations of the model function of the component.It is argued that in the case of considering the complex structure of the specified component, the construction is performed taking into account the indicators of physical processes necessary for the formation of its formation, and the model function will be represented by mathematical artifacts that are complex in structure and numerous in format.It is proposed to overcome these difficulties by forming, on the basis, developed where the corresponding physical processes are taken into account, a mathematical model of some mathematical artifact - a secondary mathematical model, which, with a reduction in accuracy acceptable for the purposes of parametric synthesis, will be much simpler given its numerical implementation.

Indoor Thermal Assessment of Medium-Cost House in Arid Climate

An environmental responsive design of building internal spaces is an important criterion and should be taken into account in the pre-design stage of the residential buildings. This study aims to analyze the existing spatial spaces of a residential building in terms of thermal performance in a hot arid climate area. Temperature data loggers were utilized in the duplex house. Results indicate that wall exposure, window size, floor level and orientation are the key to design a friendly environment of internal spaces. The neighbourhood fabric has an important role in terms of shadows and time of direct exposure to radiation. Keywords: Indoor house, Arid climate, Air temperature, spatial design eISSN: 2398-4287© 2021. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v6i18.3076

APPLICATION OF THE APPROACH TO CREATE AN INFORMATION CONSTRUCTION MODEL AT THE PRE-DESIGN STAGE OF INVESTMENT AND CONSTRUCTION PROJECTS

Abstract. At the present stage of development of the construction industry, steps to improve the efficiency of investment and construction projects can no longer be considered outside the context of construction information modeling technologies. Today, one of the main criteria for optimizing work on investment and construction projects is to reduce the time spent searching, working out and agreeing on spatial, financial, and temporal information about the construction object, therefore, the issue of the correct organization of information modeling of a construction site is quite relevant. In most cases, the design assignment is drawn up in the form given in Appendix B DBN A 2.2-2-2014 and is formal in nature. The presence of a design assignment, drawn up using the tools proposed below, reflects the thoroughness of the customer's elaboration of an investment and construction project, and reduces the risks of its implementation. The proposed methodology is based on three components of counter design, such as disaggregation, aggregation, and decomposition, from which its name – DAD –approach comes from. Allocation of structural elements in the structure of a building by disaggregation (analysis of alternative options) allows to create its model in the form of a hierarchical structure consisting of detailed and mutually synchronized parts - the configuration of the building. In accordance with the configuration of the construction site, hierarchical numbering is further reflected at all stages of design and in all its sections, incl. stamps of drawings and local estimates. This creates a unified system of interconnection and control of project sections. The creation of a construction site configuration in the form of a tree model with hierarchically numbered elements at the pre-design stage allows it to be applied at subsequent stages of the life cycle of a construction object in information modeling technologies. The use of the DAD – approach in counter-design is intended to increase the efficiency of the implementation of investment and construction projects.

Tuning Deep Neural Networks for Predicting Energy Consumption in Arid Climate Based on Buildings Characteristics

The dramatic growth in the number of buildings worldwide has led to an increase interest in predicting energy consumption, especially for the case of residential buildings. As the heating and cooling system highly affect the operation cost of buildings; it is worth investigating the development of models to predict the heating and cooling loads of buildings. In contrast to the majority of the existing related studies, which are based on historical energy consumption data, this study considers building characteristics, such as area and floor height, to develop prediction models of heating and cooling loads. In particular, this study proposes deep neural networks models based on several hyper-parameters: the number of hidden layers, the number of neurons in each layer, and the learning algorithm. The tuned models are constructed using a dataset generated with the Integrated Environmental Solutions Virtual Environment (IESVE) simulation software for the city of Buraydah city, the capital of the Qassim region in Saudi Arabia. The Qassim region was selected because of its harsh arid climate of extremely cold winters and hot summers, which means that lot of energy is used up for cooling and heating of residential buildings. Through model tuning, optimal parameters of deep learning models are determined using the following performance measures: Mean Square Error (MSE), Root Mean Square Error (RMSE), Regression (R) values, and coefficient of determination (R2). The results obtained with the five-layer deep neural network model, with 20 neurons in each layer and the Levenberg–Marquardt algorithm, outperformed the results of the other models with a lower number of layers. This model achieved MSE of 0.0075, RMSE 0.087, R and R2 both as high as 0.99 in predicting the heating load and MSE of 0.245, RMSE of 0.495, R and R2 both as high as 0.99 in predicting the cooling load. As the developed prediction models were based on buildings characteristics, the outcomes of the research may be relevant to architects at the pre-design stage of heating and cooling energy-efficient buildings.