Initial Design Stage Research Articles

Human-exoskeleton oscillation model and qualitative analysis of interaction and functional practicality of exoskeletons

In the previous exoskeleton research, the development method of the exoskeleton-function-expectation prediction in the initial design stage is lacking, which is not conducive to reviewing the system-parameter influences on exoskeleton performances, nor to exploring the exoskeleton optimization direction. In this paper, a human-exoskeleton oscillation model is designed by integrating the main functions of one load-supporting exoskeleton in the gravity direction into the double-mass coupled oscillator model. The model simplifies the human-exoskeleton coupling motion into the human-exoskeleton oscillation motion in the gravity direction, and in the oscillation process qualitatively calculates the multiple functional expectations of the exoskeleton, such as the load-supporting capability, the human-exoskeleton interaction force, the oscillation response of the backpack and the power-assistance ability. By comparing the test results of the model with previous research, the model performance was analyzed. And further, the reasons for the unsatisfying load-supporting efficiency of previous exoskeletons were explained and the influences of system parameters for the system expectations were evaluated, which helps to provide a theoretical basis for improving the exoskeleton load-supporting efficiency and human-body comfort. In addition, the combination of the exoskeleton supporting static load and the suspension system buffering dynamic load is a new direction, and the model of the paper is also beneficial to evaluate the interference degree of the exoskeleton to the suspension system.

Automated Accessibility Evaluation of Mobile Applications on Initial Stages of Design and Development

The growth of users' reliance on smartphones increases as new features and functions are continuously added to these technologies. Accessibility is an essential characteristic of information architecture in interface design research. There is a need to focus on accessibility to minimize the efforts, cost, and time during mobile application design and development. Most of the applications available on the App/Play Store lack the accessibility guidelines during development because implementing these aspects requires sufficient time and resources. Especially start-up companies normally ignore accessibility because it requires additional resources. However, perceivable design may increase profits, downloads, and reputation. Thus, the designer should ensure that their applications are perceivable and usable to satisfy the individuals. The underlying research intends to develop an automated accessibility analysis and design evaluation tool for mobile applications. Accordingly, the researchers developed a solution as a plugin for Figma. Further, the authors selected seven important techniques from the WCAG 2.1 success criterion. Finally, the proposed solution evaluates the designed screen (frame) and generates results in the report form. The proposed automated solution based on the success criterion helps the application's developers and is also useful for related stakeholders by filling the gap in the existing design related tools.

Designing of Aircraft Reinforced Carbon- Composite Torsion Boxes

At the initial design stage, there is a problem of determining the thicknesses of the load-bearing elements of an aircraft structure made of composite materials. The paper presents the intelligent design of the composite caisson structural strength. Intelligent design is based on the finite element method. The task of optimization used the objective function of minimum mass and setting some constraints including no types of buckling al-lowed. In optimization, the parameter is the thickness of the element, which changes in the process of minimizing the objective function for elements made of PCM by an amount equal to the thickness of the package. The results show the strength margins of spar webs and rib webs of the caisson of vertical empennage torsion box satisfy the safety factor design.

Conceptual Design Algorithm Configuration Using Generative Design Techniques

Purpose: The aim of this study is to investigate design automation and generative design cases in the field of construction using artificial intelligence (AI) and generate alternatives using generative design techniques in the planning and early design stages of a building. Previous studies indicate that AI-based design automation techniques can be used to design the paradigm of the existing construction and design field, thus improving the construction productivity. In this study, we have conducted additional research to understand the application of generative design in the planning and initial design stages of buildings to provide research directions for Korean design automation and generative design suitable for domestic situations. Method: We have used Autodesk

Trajectory Tracking Nonlinear Controller for Underactuated Underwater Vehicles Based on Velocity Transformation

This paper proposes an algorithm that performs the task of tracking the desired trajectory for underactuated marine vehicles (primarily underwater) that move horizontally. The control scheme, which takes into account model inaccuracies and external disturbances, was designed using the quantities obtained after the transformation of the dynamic equations of motion resulting from the decomposition of the inertia matrix. This, in turn, led to the equation of dynamics with a diagonal inertia matrix. A specific feature of the offered controller is its dual role. It not only allows tracking the desired trajectory, but at the same time, makes it possible to estimate the impact of dynamic couplings when the vehicle is in motion. Such an approach to the tracking task is important at the initial design stage when the choice of the control algorithm has not yet been decided and experimental tests have not been performed. This is feasible because the new variables after the velocity transformation include not only vehicle parameters, but also actual velocities and forces. Therefore, it is also possible to track the original variables. The theoretical results were followed up with simulation tests conducted on a model with three degrees of freedom for two underwater vehicles.

Numerical investigation and estimation of active earth thrust on gravity retaining walls under seismic excitation

Earthquakes can create severe damage to retaining structures. A numerical study is carried out to understand the seismically induced active earth pressure force on free-standing gravity retaining walls. Dynamic behavior in terms of acceleration amplification/deamplification, deformation mechanism, and earth pressure force are examined. Further, the influence of input peak ground acceleration (PGA), retaining wall height, Young's modulus of the wall, relative density of soil, and soil-structure interaction on total active earth pressure force (Pae) are investigated. The results show that Pae decreases until PGA value is around 0.55 g and later increases for higher values. The primary cause for this response is the loss of wall-soil interaction due to the overturning effect, which dominates until PGA approaches 0.55 g. Also, the generation of failure wedges causes an increase in Pae after 0.55 g. Sensitivity analysis concludes that Pae is highly sensitive to PGA, wall height, and soil-structure interaction. Based on regression analysis, an equation is proposed for the total active thrust. Later, the accuracy of the equation is confirmed by comparing it with the response of FE analysis and established study. This study contributes to developing an equation that is anticipated to provide total active thrust at the initial design stage under comparable work environment.

Hazop Analysis of a Bioprocess for Polyhydroxyalkanoate (PHA) Production from Organic Waste: Part B

The production of polyhydroxyalkanoates (PHAs) from industrial waste streams has attracted the attention of researchers and process industries because they could replace traditional plastics. The integrated treatment of civil wastewater along with organic solid wastes in a novel “urban biorefinery” is a very important option to implement a synergic treatment of all relevant bio-waste streams. The development of new biotech processes should consider the occupational health and safety issues from the initial design stages. Among the process hazards analysis techniques, HAZard and OPerability (HAZOP) methodology is widely used for studying both the processes hazards and their operability problems, by exploring the effects of any deviations from design conditions. In the present study, a modified version of HAZOP methodology has been applied to a three-step process developed at pilot scale in the Treviso municipal wastewater treatment plant in order to produce PHA. This paper (part B) shows the results of HAZOP analysis applied to the second process step aimed at culturing the activated sludge under periodic feeding conditions into a sequencing batch reactor (SBR). The analysis applied to the process conditions, corresponding to the maximum PHA content in the biomass, has led to the identification of technical solutions to mitigate the main occupational risks.

UNIVERSAL DESIGN AS THE BASIS OF FORMING AN ACCESSIBLE ARCHITECTURAL ENVIRONMENT OF MODERN CITIES

The article examines the problems of creating an accessible architectural environment in Ukrainian cities. The relevance of the study is determined by: a large percentage of people with disabilities in the structure of the population of Ukraine, including people with disabilities, an increase in their number as a result of hostilities; lack of accessibility conditions for low-mobility population groups in most settlements; lack of understanding by society of the complex problem of accessibility; absence at local levels (in local administrations) of a clear algorithm of actions to ensure the accessibility of the architectural and urban planning environment. The purpose of the article is to reveal the role of universal design as a basis for the formation of an accessible architectural environment of modern cities.
 Universal design is a cost-effective approach, because it meets the needs of all users already at the initial stage of development and design and eliminates future irrational costs. The concept of universal design provides not only architectural accessibility to the building, but also the ergonomics of all elements of the object-spatial environment, the physical and psychological comfort of being in the architectural environment, and promotes the social integration of people with disabilities.
 Universal design in the field of architecture and urban planning and the formation of an accessible architectural environment is a process that begins with the designer's awareness of his own social responsibility for the formation of the level of comfort of the living environment that people experience throughout their lives, with its orientation to the variety of needs, opportunities and experiences of users.
 The application of the principles of Universal design and the corresponding architectural and design methods of their implementation are currently the optimal means of adapting the architectural and urban planning environment to the needs and capabilities of all categories of users, including those with limited mobility. The publication analyzes in detail the importance of many specific techniques for the formation of an accessible architectural environment: the absence of stairs, a wide entrance with sliding doors, adaptability of workplace equipment, convenient control panels, presentation of information in an easy-to-understand format (in the form of symbols, icons, infographics), tactile contrasting color coating.
 The main obstacles on the way to the application of the principles of Universal Design and the formation of an accessible architectural environment of Ukrainian cities are the low level of social awareness of citizens, as well as the insufficient level of funding.

Application of in-situ blocked forces for characterising structure borne vibration of heavy industrial machinery

Industrial machinery can generate excessive vibration, potentially reducing their productivity and disturbing their surroundings. Thus, it is essential to control vibration in industrial environments and accurate predictions are required to adopt mitigation measures in the initial design stages. It is first necessary to perform measurements on the vibration source to characterise its operational behaviour, and the obtained properties can be expressed in terms of its blocked forces according to ISO 20270:2019. The data can be obtained from the source mounted on a specific receiver, but still deliver intrinsic quantities that remain valid for any different receiver structures. Although good agreements have already been achieved between predictions and on-board validations from light weight structures, proving the theory is well understood, it has not yet been applied effectively to heavier assemblies which will be the focus of this work. A source characterisation case study is presented in this paper for a typical heavy industrial installation known as a press softly mounted on an inertia block isolated from the surrounding factory floor. A description of how the passive properties of the press were obtained and vibration predictions at different positions of the coupled assembly will also be given.

Investigation of Microservice-Based Workflow Management Solutions for Industrial Automation

In an era ruled by data and information, engineers need new tools to cope with the increased complexity of industrial operations. New architectural models for industry enable open communication environments, where workflows can play a major role in providing flexible and dynamic interactions between systems. Workflows help engineers maintain precise control over their factory equipment and Information Technology (IT) services, from the initial design stages to plant operations. The current application of workflows departs from the classic business workflows that focus on office automation systems in favor of a manufacturing-oriented approach that involves direct interaction with cyber-physical systems (CPSs) on the shop floor. This paper identifies relevant industry-related challenges that hinder the adoption of workflow technology, which are classified within the context of a cohesive workflow lifecycle. The classification compares the various workflow management solutions and systems used to monitor and execute workflows. These solutions have been developed alongside the Eclipse Arrowhead framework, which provides a common infrastructure for designing systems according to the microservice architectural principles. This paper investigates and compares various solutions for workflow management and execution in light of the associated industrial requirements. Further, it compares various microservice-based approaches and their implementation. The objective is to support industrial stakeholders in their decision-making with regard to choosing among workflow management solutions.

Ecological technology of green building in the initial stage of design based on BIM technology

At present, the whole world is faced with a common topic, that is, the contradiction between energy consumption, serious fog, the continuous rise of PM2.5, plastic waste, white pollution and other environmental pollution and the worldwide energy shortage. In this paper, aiming at the international new town construction project in Xigu District, Lanzhou, Revit software is used to establish a physical model for data integration and integrated management of the geometric information of building space, functional information of building space, building materials and other related data information of the project, and an analysis model for the scheme design of the residential building of the project is obtained, and ecological and technical factors such as energy consumption analysis, lighting analysis, indoor lighting analysis, solar radiation analysis, shading and thermal comfort analysis of the project location are analyzed. The research shows that the thermal performance, energy consumption simulation analysis and hourly heat gain/loss analysis of the envelope in the coldest weather in the local area show that the heat conduction of the envelope is small under the three conditions of structural design (case A), standard limit (case B) and hypothetical construction (case C), which indicates that the solar radiant heat is mainly related to the material performance of the external window when the heat transfer coefficient of the roof is close, and the heat gain and loss between regions has little change.

Hazop Analysis of a Bioprocess for Polyhydroxyalkanoate (PHA) Production from Organic Waste: Part A

The number of bioprocesses for the circular economy of organic waste has grown in recent years. Implementation of new processes and technologies should consider occupational health and safety issues from the initial design stages. Among the process hazards analysis techniques, HAZard and OPerability (HAZOP) methodology is widely used for studying both the process’s hazards and their operability problems, by exploring the effects of any deviations from design conditions. In the present study, a modified version of HAZOP methodology has been applied to a three-steps process developed at pilot scale in the Treviso municipal wastewater treatment plant in order to produce polyhydroxyalkanoate (PHA) as the final high value product. This paper shows the results of HAZOP analysis applied to the first process step (acidogenic fermentation) aimed at volatile fatty acids production. The analysis has been applied to the process conditions corresponding to the maximum PHA content in the biomass. The HAZOP study results showed that this methodology allowed a comprehensive exploration of conventional chemical engineering process hazards and biological hazards. Final piping and instrumentation diagrams (P&IDs) for acidogenic fermentation have been designed, identifying all prevention measures aimed at managing the hazard and operability issues. The P&ID shows the interconnection of equipment and the instrumentation required for controlling the process.

A Suggestion of the Alternatives Evaluation Method through IFC-Based Building Energy Performance Analysis

In a rapidly changing modern society, the construction industry is facing various issues, including the Fourth Industrial Revolution and climate change. Research on convergence between technologies such as artificial intelligence, AR/VR, IoT, and metaverse, and sustainable technologies such as green buildings and eco-friendly energy is being attempted in each field. The most important thing in the development of these technologies will be the interoperability of data. BIM is a technology that can effectively store data regardless of the size of a building or the amount of information and can be shared and stored without loss of data through an open format called IFC (industry foundation classes). This study aims to present a plan to generate alternatives and evaluate energy performance by analyzing the shape of the envelope for amorphous buildings through IFC. Design elements were derived through analysis of previous studies, and alternatives were automated by developing interfaces that can generate shapes according to the derived design elements. The generated alternatives can be compared and analyzed through the analysis of building energy by developing an evaluation system based on IFC. Based on the quantitative results in the initial design stage, the reliability of the design proposal considering the performance of the building is improved, and the process and cost can be predicted in advance; thus, it is expected to be an efficient decision support tool.

Research on multiple transient modeling scheme for full-cycle design of the 12-pulse PSR rectifier

PurposeThis paper aims to propose a novel multiple transient modeling scheme for the 12-pulse phase-shifting reactor (PSR) rectifier to enhance the efficiency of full-cycle design evaluation.Design/methodology/approachThe detailed time-domain method is adopted to model the rectifier at the behavioral layer. The diode bridges/transformer model at the architecture layer is established by using the switch function and Park transformation. The frequency domain model at the functional layer is derived with the time-varying Fourier decomposition and frequency-shifting. At the component layer, the magneto-thermal characteristics of the rectifier are analyzed with field-circuit and magnetic-thermal coupling methods. A computer-aided design program integrating multiple modeling is also developed for industrial product design.FindingsThe function layer modeling is preferred in the initial design stage, making up for the lack of modeling accuracy at the architectural layer and the lack of modeling rapidity at the behavioral layer. The component modeling is irreplaceable for the detailed evaluation in the latter design stage. The multiple modeling scheme based on the four-layer modeling helps the designers achieve high-quality products with a short development cycle.Originality/valueThe singular transient modeling cannot cover the needs of different stages in the full-cycle design evaluation. This paper fills this gap with a novel multiple modeling scheme. Meanwhile, the proposed multiple modeling scheme and developed computer-aided design program provide a great convenience for full cycle design evaluation of the 12-pulse PSR rectifier.

Integrating BIM with carbon footprint assessment of buildings: A review

Climate change is one of the world's majorconcerns today.In addition to being one of the largest energy consumers, the building sector emits substantial amounts of greenhouse gases (GHGS). Globally, the building sector consumes 40% of the annual energy and emits 30% of the GHGS. The effort is therefore made throughout various phases of planning and design to measure emission levels and energy consumption concerning local climate, living culture, ecology, and construction style. To reduce Carbon Dioxide (CO2) emissions and energy consumption, international research is being carried out to develop a Building Information Modelling (BIM) based detection system that allows easy estimation of CO2 emissions & energy consumption. Such emissions can then be analysed quickly and objectively, and the necessary changes to support energy-efficient design can be implemented. The study focused on the initial stages of design because choices made at this time determine a large portion of a building's life cycle effects and cannot easily be changed afterwards.

Numerical analysis of propellers for electric boats using computational fluid dynamics modelling

In the maritime industry, propellers are the most commonly used form of propulsion and are core to the optimum performance of a ship. As marine propellers have complicated geometries, the flow around the propeller is also complicated. Generally, the performance characteristics of a propeller are determined and analysed by experiments like open water and self-propulsion scale model tests which are costly and time-consuming at the initial design stage. In this study, the CFD simulations were performed to evaluate propeller performance. Three Wageningen B-series propellers with varying Expanded Area Ratios (EAR) were modelled with respect to some design constraints, such as ship speed and rotational velocity. The performance of the hydrodynamic coefficients, thrust, torque and open water efficiency are then analysed. These characteristics are then validated against experimental data obtained from the Netherlands Ship Model Basin open water test in Wageningen and used to investigate the flow behaviour. The analysis considers the Multiple Reference Frame (MRF) model. This research aims to provide a well-founded framework for applying CFD in the analysis and selection of Wageningen B-series propellers, as well as investigating the relationship between EAR, flow behaviour, thrust coefficient, and torque coefficient for electric boats. The results showed that a lower thrust and torque coefficient manifested in improved flow behaviour, increasing efficiency by up to 62%. In addition, the outcome revealed that the lower expanded area ratio of 0.6 is more suitable for electric boats, creating a larger pressure difference of 1.079 MPa and generating extra potential thrust at the same advance ratio, which leads to greater open water efficiency.

Extent of damage analysis of naval ships subject to internal explosions

A well-balanced naval ship design to enhance the survivability from the initial design stage in parallel with other designs focusing on the major function and its inherent mission is considered as a desirable design trend in ROK navy since Cheonan sinking accident. Because it is difficult to estimate a hit location of a given threat for survivability evaluation, a statistical approach based on multiple-hit scenarios is frequently addressed, and it is necessary to accomplish rapid analyzes considering the tight design schedule. In addition, accurately estimating the extent of damage caused by the given threat is also an important matter to secure the reliability of evaluation. In particular, the empirical formula-based damage extent estimation method, which is frequently used for initial rapid vulnerability analysis, has limitations in not faithfully reflecting the latest technology advances such as hull design changes and diversification of threats, so researches on this have been continuously accomplished. In this study, a method for analyzing the extent of damage was developed considering the structural response of a ship to damage under a blast load. The proposed method quickly and easily calculates the extent of damage using physical design parameters together with the accurate analysis results and is also very effective at the initial design stage of the naval ship (e.g., in evaluating various design candidates for structural configurations). To show the effectiveness of suggested method, FLACS, a well-known commercial program for explosion analysis, is used for the analysis of nine representative scenarios together with the stepwise validations of the suggested procedure; the analysis results are observed the same in most cases with the developed program based on the proposed procedure, with a difference of approximately 15% for one scenario.

Формирование структуры интерфейса: оптимальные задачи

Discusses the problems that arise in the process of interface design at the initial design stage. At this stage, the main necessary system functions and user scenarios are determined; additionally, a general interface structure is formed, intended for a generalized representation of the future interface, highlighting the main and secondary areas, objects, functions, which identifies the type and direction of connecting components and blocks, as well as a sequence of commands and actions. As a model, the design of the general interface structure is considered as the definition of a number (set) of rules that determine the importance and sequence of using the existing set of functional blocks, which are then treated as vertices of a digraph, while the need to provide (possibility) transitions from one block to another is treated as transitions between vertices of a digraph (arc). A thorough discussion is provided describing in detail the process of constructing a basic graph and determining the necessary parameters of vertices and arcs, based on the integrated use of the relevant experts’ knowledge (users and developers). A number of possible statements of unconstrained optimization problems on the resulting graph and their features are formulated and analyzed. The problems of conditional optimization on the obtained graph are defined and studied. The proposed approach and the solution of optimization problems at the appropriate stages will help to determine the most efficient structure of the interface designed from the point of view of the user and system capabilities, as well as under limited time and other resources to complete tasks.

Predicting Deflections in Beams using Machine Learning Algorithms

Prediction of deflections in structures is imperative for safety and stability. Classical approach and numerical solutions are currently being employed to predict the deflections of beams. However, the results from these approaches varies when compared to tests. But testing is time consuming and expensive. During the initial design stages, designers would like to quickly perform various design iterations. In order to get a quick and accurate prediction, Machine Learning models are used. In this study, regression algorithms like linear, Lasso and Ridge are used to predict the deflections in three different beams: cantilever, clamped-clamped and overhang. The database for training the algorithm is generated using the principle of superposition of forces. Around 100 datasets were generated for each type of beams in excel. Python Scikit Learn library is used to train and test the regression algorithm. The root mean square error (RMSE) for the three types of beams is nearly zero. Hence, the linear regression model resulted in high accuracy predictions. This study proposed an effective model that is cheap, accurate and efficient, to help designers predict deflections at an early stage of the design.

KINEMATIC ANALYSIS OF A MECHANISM WITH SIX DEGREES OF FREEDOM WITH A CIRCULAR GUIDE

In this article, the mechanism of a parallel structure with six degrees of freedom with a circular guide and consisting of three kinematic chains is investigated. The paper considers the problem of structural synthesis, solves the problem of kinematic analysis, and proposes an algorithm for determining and studying the working area. The working area of the mechanism is six-dimensional and difficult to visualize. As an alternative to the wellknown approaches to solving this problem, a technique for numerical scanning over discrete grid points is proposed. Grid dimensions are assigned at the initial design stage and can be adjusted depending on the problem statement, while at each grid point three absolute angular coordinates are scanned with a certain step.