Designs, Volume 4, Issue 3 (September 2020) – 23 articles

Printed circuit boards, chemical etching, and computer numerical control milling currently dominate industrial processes for manufacturing microwave components. However, these manufacturing methods do not provide the flexibility for customization possible with additive manufacturing. Additive manufacturing (AM) has the potential to fabricate microwave components for desired frequency ranges with less effort in prototyping and fabrication. Relative permittivity (${\epsilon }_{\mathrm{r}}$) of materials is a critical parameter in microwave component design, yet the value changes during the AM process. This article investigates how relative permittivity for nylon substrates, created with AM, changes with different infill densities and infill patterns. The measurement method and procedure can be used to design AM microwave components like antennas or dielectric-filled waveguides with desired characteristics. The two-microstrip-line method was used and improved for the accurate and convenient measurement of the relative permittivity of AM nylon substrates. Several nylon substrates with different infill patterns, including rectangular, hexagonal, triangular, and solid, were fabricated with AM to demonstrate how the relative permittivity value changes as the infill density increases. A linear relationship between the infill density of the rectangular pattern and the substrate permittivity was found. The permittivity data were applied to the design of a rectangular patch antenna for use in the 2.5-GHz WiMAX band. The fabricated antenna with AM, which was tested using a vector network analyzer, showed good agreement with simulation results. The method and procedure of permittivity measurements are specially designed to be applied in the design of microwave components with AM dielectric substrates. Full article

The figure of Leonardo da Vinci has been extensively studied. In fact, the Leonardiana Library brings together tens of thousands of titles on Leonardo and his work. During the second half of the 20th century, various treaties were published focusing on Leonardo’s activity as an engineer, and more recently, an increasing number of scientific articles that focus on certain aspects of the prolific work of the genius such as construction, mechanics, strength of materials, etc. have been published. This article analyses the main contributions of the Tuscan genius in the field of design focusing on his processes for generating new solutions, his developments regarding graphic representation techniques, his improvements in plotting and measuring instruments, and how some of his devices were implemented and continue to maintain their usefulness. Full article

Current frugal design practice is focused on the cost reduction of the product. Despite advancements in the domain of frugal Innovation, it is not systematized to develop products for all sets of users, including marginalized society. Many design researchers and engineers now dedicate time and knowledge to producing practical solutions to enhance the quality of life of the marginal community. The approach currently being adopted restricts the development of products intended for all segments of the users. In this paper, cumulative frequency distribution analysis and the Relative Importance Index is used to identify the essential attributes, which contribute to delivering actual frugal products in terms of functionality, usability, performance, affordability, accessibility, aesthetics, and robustness. The framework is beneficial to eradicate the discriminatory effect of being labeled as “Jugaad” users. Full article

Chemical process industries are running under severe constraints, and it is essential to maintain the end-product quality under disturbances. Maintaining the product quality in the cement grinding process in the presence of clinker heterogeneity is a challenging task. The model predictive controller (MPC) poses a viable solution to handle the variability. This paper addresses the design of predictive controller for the cement grinding process using the state-space model and the implementation of this industrially prevalent predictive controller in a real-time cement plant simulator. The real-time simulator provides a realistic environment for testing the controllers. Both the designed state-space predictive controller (SSMPC) in this work and the generalised predictive controller (GPC) are tested in an industrially recognized real-time simulator ECS/CEMulator available at FLSmidthPvt. Ltd., Chennai, by introducing a grindability factor from 33 to 27 (the lower the grindability factor, the harder the clinker) to the clinkers. Both the predictive controllers can maintain product quality for the hardest clinkers, whereas the existing controller maintains the product quality only up to the grindability factor of 30. Full article

The paper describes the use of a single-phase three-stage solid-state transformer in networks with non-sinusoidal voltages in order to improve the quality of electricity. An active-inductive load was chosen as the load. The solid-state transformer was simulated by the Matlab/Simulink software. Its performance was analyzed and the parameters for optimal performance were specified. The voltage and current graphs on the load and their spectral analysis are given. Total harmonic distortion was evaluated for current and voltage. As a comparison, the operation of a classic transformer was simulated. Modeling shows that solid-state transformer copes with improving the quality of electricity better than a classical transformer. In addition to improving the quality of the load current, the solid-state transformer protects the consumer from overvoltage, voltage dips, and other transient phenomena, due to the accumulated supply of electricity in the capacitors of the DC-Bus. Full article

This work presents an extensive numerical simulation to analyze the influence of the coating layers on the performance of construction systems, in order to make the constructions projects feasible, not only economically but also technically. Through numerical simulations based on a defined reference model, the present work studied the influence of different layers of floor, roof and internal and external wall systems, on the acoustic, thermal, and luminous performance of buildings in Brazil. The results showed the materials and elements with the greatest influence on: lighting performance are the internal finishes of the environment and the type of glass used in the external windows. On thermal performance, all elements of the roofing system and façades, especially an absence of external cladding and the use of thermal blankets on the roof, have greater influence. The acoustic performance of the façade function on the external windows and acoustic performance of the floor system are mainly influenced by the thickness of the structural element and the use of a ceiling and acoustic blanket; acoustic performance of internal walls is affected by typology of the structured element of the wall and thickness. Full article

In this paper, a model for a single stage plasma gasification system for marine vessels characterized by significant waste production is proposed. The main objective of the model is to investigate the effects of different feedstock compositions on key parameters, such as electrical power produced and heat recovered. The different types of waste generated onboard are described along with their environmental impacts. Specific attention is given to solid wastes, sewage sludge and plastic wastes as potential feedstock. Their average generation, proximate and ultimate analysis are defined, as input to the process model. The process assumptions used in the simulation model are illustrated. The system model is divided into five units: the pre-treatment unit; the gasification unit; the syngas cleaning unit; the energy conversion unit; and the heat recovery unit. Four operational scenarios are investigated to consider several variations of composition of the main feedstock. From the results of the simulations, the system model shows good feedstock flexibility, and the possibility of operating in net electricity gain conditions. The cold gas efficiency of the process is also assessed and its maximum value is obtained for the highest concentrations of sewage sludge (33.3%) and plastic (16.7%). Other parameters investigated are the combustion temperature, sorbent consumption in the cleaning process, feedstock and syngas lower heating value LHV. Full article

Renewable energy resources for energy generation in the Gaza Strip (GS) emerge as a complementary resource, not only to meet the need of society for energy in various forms, but also to find available, sustainably, and less costly resources for institutions as with individuals. These resources could provide safety in use, increase energy security, and address environmental concerns. This work aimed to assess the renewable energy potential in the GS, which has few natural resources and a real crisis in energy supply. Therefore, an integrated evaluation methodology is assumed for renewable energy potential; the methodology comprises mathematical as well as software programming to assess the renewable energy. The results reveal the assessment of the existing four renewable energy sources: solar, wind, wave, and biomass. The estimations exhibit that the solar and biomass resources are dominant. The methodology consists of mathematical models for calculating the energy outputs from different resources in the study area. ArcGIS 10.1 software used for calculating solar radiation, WindSim 9.0.0 software for estimating wind energy and OpenWEC software tool for evaluating the force stored in coastal waves. The potential of each energy and the integration of all are depicted in individual maps by ArcGIS. It was found that if anaerobic digestion technology is applied, 65.15 MW electric power could be produced from about one-and a third million tons/year of biomass. Depending on the available statistical data due to the specified annual time period and the household electric demand that is about 120 MW at the corresponding time, this means that the energy from biomass can cover more than half of the demand. In addition, solar energy potentials were estimated to reach 1195 GWh/year. Therefore, the existing power may be replaced by biomass and solar energy. It also demonstrates that the energy potential maps can be used as metrics for possible sustainability projects in the GS. Full article

Researchers have proposed different methods for testing digital systems and circuits in the last couple of decades. The need for testing digital logic circuits has become more important than ever due to the growing complexity of such systems. During the design phase, testing is focusing on design defects, as well as manufacturing and wear out type of defects. Failures in digital systems could be caused, for example, by design errors, the use of inherently probabilistic devices, and manufacturing variability. As a way to test digital systems in a more efficient way, automated test generation has been proposed to automatically create tests that can quickly and accurately identify faulty components. Examples of such techniques are the sequential test generation, the scan path testing, and the random test generation techniques. With the research domain becoming more mature and growing, it is essential to systematically identify, analyze, and classify these contributions. We performed a systematic mapping study of automated test generation for digital circuits aimed at providing an overview of the application of these techniques. We focused on three of the most widely-used and well-supported hardware description languages (HDLs) for digital systems: Verilog, SystemVerilog, and VHDL. Our results suggest that the majority of the test generation methods for digital circuits are focused on the behavioral and register-transfer design levels. Fault-independent and fault-oriented test generation are the most frequently reported types of test generation methods, while HDL model simulation is the most common test generation technology used to search for test cases in these academic studies. While the results are suggesting a growing interest in this area, the majority of articles are published as conferences papers. Our results show that only 31% of the methods are implemented as software tools and only 63% of all contributions are actually generating executable test cases. This study makes three important contributions, (i) a state-of-the-art of test generation for digital system designs research is provided, (ii) the reported characteristics are identified in both the primary papers and experimental reports, (iii) gaps and opportunities for future test generation for digital system designs research are identified. Full article

This is the first of two companion articles which aim to address the research on Architecture and Steel. In this article, some architectural projects are analyzed to show the potentiality to conjugate architectural conception and steel structures, as well as to show the contribution and influence from architectural history. This article also aims to contribute to the reflection of the knowledge and legacy left to us by several architects throughout the history of architecture in using aesthetic, visual and structurally safe profiled steel structures in architectural conception. The presented analysis and reflection are based on the characteristics and influences of the Industrial Revolution and, mainly, the Modern Movement, where the first housing projects came up with this constructive system, combined with the “simplistic” ways of living in architecture, highlighting the relationship with the place, cultural, spatial and typological references, the structural systems and associated materiality. In view of the diversity of alternatives allowed by the use of steel “Skeletons”, modular and standardized, combined with a huge variety of existing materials and constructive complexity, well combined and interconnected, it is possible to obtain a final product whose characteristics seduce by their beauty and elegance. Moreover, the practical and functional comfort which allows the safeguarding of the architectural integration of such product, with the necessary serenity in space and nature, in full environmental integration, is also emphasized. Full article

Design is about understanding the system and its users. Although User Experience (UX) research methodologies aim to explain the benefits of a holistic measurement approach including explicit (e.g., self-reported) and implicit (e.g., automatic and unconscious biophysiological reactions) data to better understand the global user experience, most of the personas and customer journey maps (CJM) seen in the literature and practice are mainly based on perceived and self-reported users’ responses. This paper aims to answer a call for research by proposing an experimental design based on the collection of both explicit and implicit data in the context of an authentic user experience. Using an inductive clustering approach, we develop a data driven CJM that helps understand, visualize, and communicate insights based on both data typologies. This novel tool enables the design development team the possibility of acquiring a broad portrait of both experienced (implicit) and perceived (explicit) users’ experiences. Full article

This paper introduces the concept of an intelligent vase that combines the cultivation of plants with psychotherapy for the Alzheimer’s adjuvant therapy (from now on, referred to as AD) of patients. RECALL (The name of intelligent vase which defined by this paper), which includes hardware and software applications, as well as a unique hand gesture interaction method, is able to collect patients’ hand gestures and play photos, to remind patients of the plant’s growth status. To evaluate our conceptual system, we created a preliminary prototype. We conducted an experiment with leap motion. This project tries to explore a kind of interaction method by cultivating plants to simulate cognitive training activities, to stimulate memories through family pictures, to slow down the cognitive decline from AD, to incorporate non-drug intervention into the family life of AD patients, to reduce the expenditure, time, and energy costs, and to improve the quality of life of patients and their families. Full article

This paper deals with an experimental study on the modeling and identification of the hysterical behavior of inerters. Unlike existing methods that can only consider a constant inertance to capture a static model of the device, we develop three different dynamic models for a ball-screw type inerter. To eliminate the effects of the measurement noise, an empirical mode decomposition (EMD) method is proposed. Then, three dynamic models—the Dahl, LuGre and Bouc–Wen model—are used in order to model the friction behavior of the device. Using the least-square optimization method, the parameters of the models are estimated. The results of the tuned models are compared together within different frequencies. The good agreement between predicted and measured data shows that LuGre and Bouc–Wen models can be effective for modelling the hysteretic behavior of friction inside the inerter mechanism. It is also shown that the Bouc–Wen model has better correlation with the experimental results in all test frequencies and amplitudes. Full article

This study was stipulated by today’s limited living conditions of middle income households in Bangladesh who have economic constraints that contribute to hindering improvement of their existing domestic settings that may affect occupants’ mental health and wellbeing. The design of domestic living environments tend to influence occupants’ emotions, feelings and moods. Thus, domestic environmental experiences need to be examined and incorporated into architectural design decisions. To understand the notion of such experiences, this study reviewed literatures concerning the related domains extensively. This study found the significant impact of domestic environments on human perceptions. Each design of domestic settings affects occupants’ emotional responses positively or negatively. Through this study, the term domestic environmental experience was defined as users’ experiences of cognitive perceptions and physical responses to their domestic built environment. In addition, it led to proposing the composition of domestic environmental experiences that need to be correlated with architectural design solutions. Nonetheless, this study did not examine the correlation where the emerging notion of Environmental Experience Design (EXD) may serve as the mediator. Accordingly, this new horizon of EXD research needs to be explored further with the aim to improve domestic built environments in Bangladesh which were the original driver of this research. Full article

Effectively communicating properties of environmental products to consumers can be challenging. This especially pertains to highly environmentally conscious (HEC)—yet skeptical—consumers, since this target group must balance the need for reliable product knowledge with high sensitivity to often ambiguous nonverbal cues about a product’s environmental friendliness (e.g., environmental pictures). Using a group-specific (2 ×) 2 × 2 repeated-measures experimental study, we investigated the effect of communication-channel-specificity (verbal and nonverbal) to convey the environmental friendliness of products and evaluated consumers’ environmental skepticism and attention during product presentation. Environmental information delivered via a verbal/text-based communication channel translates into low skepticism for both HEC and low environmental consciousness (LEC) consumers. However, nonverbal/pictorial communication proved persuasive only for LEC consumers; HEC consumers exhibited high levels of skepticism, which, in turn, decreased the products’ perceived environmental friendliness. The analysis of combined verbal and nonverbal communication presented here provides a promising framework for effective green marketing communication. Full article

This is the second of two companion articles which aim to address the research on architecture and steel. In the first article, some architectural projects were analyzed to show the potentiality to conjugate architectural conception and steel structures (in sight), as well as to show the contribution and influence from architectural history. As a result of the previous work, this second article discusses the development of an innovative prototype in steel structure, which constitutes a modular system applied for a single-family housing. In this prototype, steel is part of the design concept, not only as a structural element, but also as an aesthetic element. The needs of contemporary “living” are reinterpreted, considering all the changes and cultural influences due to globalization, compared with the living in Portuguese popular architecture, with its simplistic character and minimal spaces, and referring to a place. The proposed modular system, which is applied repeatedly, shows a huge potential for reorganizing, in a short period of time, urban areas with housing shortages in cases of emergency, while respecting population needs and providing construction quality. This Prototype Model, which combines the architectural concept with the lightweight character of steel structures, aims to provide an “other” way of “living”. It transmits “harmony” both in the experience of the interior space and in its relationship with the outer space, respecting the cultural references. In this study, the prototype is applied to popular Portuguese schist architecture, combining the basic structuring idea and the way how the project develops for the application of the conceptual and constructive process, thus relating two periods of architecture. Full article

Implementing business and manufacturing process reengineering is challenging and poses major issues. The dependence issues between process functions during the implementation phase are the main reason for the high failure rate of process reengineering. The incompetence in identifying the dependence makes existing business process reengineering approaches static for modern business and manufacturing process structures. This paper has implemented a new process reengineering approach called the Khan–Hassan–Butt (KHB) methodology that incorporates the process interdependence algorithm to identify the dependence issues. The KHB method is a hybrid process reengineering approach to identify dependence issues before implementing changes; thus significantly reducing the failure rate of implementing business process reengineering. The KHB method has been implemented in a Bangladesh fabric manufacturing facility. The mapping and verification of the process have been completed using the WITNESS Horizon 22.5 simulation package. The case study has investigated the fabric production process and identified the dependence issues between each function and suggested changes to optimize the process. The outcome has shown significant improvement in production output and process efficiency. Full article

Emerging 3D printing technologies are enabling the rapid fabrication of complex designs with favorable properties such as mechanically efficient lattices for biomedical applications. However, there is a lack of biocompatible materials suitable for printing complex lattices constructed from beam-based unit cells. Here, we investigate the design and mechanics of biocompatible lattices fabricated with cost-effective stereolithography. Mechanical testing experiments include material characterization, lattices rescaled with differing unit cell numbers, topology alterations, and hierarchy. Lattices were consistently printed with 5% to 10% lower porosity than intended. Elastic moduli for 70% porous body-centered cube topologies ranged from 360 MPa to 135 MPa, with lattices having decreased elastic moduli as unit cell number increased. Elastic moduli ranged from 101 MPa to 260 MPa based on unit cell topology, with increased elastic moduli when a greater proportion of beams were aligned with the loading direction. Hierarchy provided large pores for improved nutrient transport and minimally decreased lattice elastic moduli for a fabricated tissue scaffold lattice with 7.72 kN/mm stiffness that is suitable for bone fusion. Results demonstrate the mechanical feasibility of biocompatible stereolithography and provide a basis for future investigations of lattice building blocks for diverse 3D printed designs. Full article

Recently, more importance has been attached to consumers’ emotional feelings in the course of product design. Designers must convey positive emotions, such as surprise and affection, to consumers through their designs. For this purpose, image boards have been frequently used in design to position product emotional feeling and arouse design ideas. A large number of pictures are often needed for constructing an image board. However, it is time-consuming and labor-intensive to find appropriate pictures and the pictures that are finally collected may not reflect the expected image of consumers. Therefore, this study aims to take Lifestyles of Health and Sustainability (LOHAS) as an example to build a user-driven database for image boards. In this research, 16 LOHAS representatives were identified and recruited by using a lifestyle questionnaire to collect, and then screen out 50 proposed pictures relevant to the image of LOHAS. Since image boards are usually used by designers, in order to include their ideas, another 16 pictures were selected by the invited experienced product designers to create a comprehensive pool of 66 proposed pictures. Design experts were asked to select six key image adjectives, which included healthy, environmentally friendly, sustainable, natural, simple, and ecological for describing images of the LOHAS, from the vocabulary pool collected by general respondents, LOHAS representatives, and designers. Next, 219 LOHAS subjects were required to carry out a semantic differential assessment of each of the 66 proposed pictures with the six key images, and then two types of analyses on the collected data from the semantic differential assessment. Through mean analysis and grey correlation analysis, the recommended pictures representing LOHAS or six key adjective images were selected. The research results put forward three database application models. The results of this study are expected to be used by designers, users, manufacturers, and educators to help improve product design efficiency in the future. Full article

Due to a symbiotic relationship, economic growth leads to greater energy consumption in transportation, manufacturing, and domestic sectors. Electricity consumption in the global south is rising as nations in the region strive for economic development. Due to the high costs of fossil fuels and environmental issues, these countries are planning exploitation of their renewable energy potential for meeting their energy needs. In this paper, we take Myanmar as a case study for which photovoltaic (PV) is seen as the preferred technology owing to its modular nature and Myanmar’s tremendous PV potential. To create sustainable systems, the impact of diurnal PV profiles on electricity demand profiles needs investigating. Accurate load forecasts lead to significant savings in operation and planning and maintenance. Artificial neural networks (ANNs) can easily be used for load profile forecasting. This work proposes a three-stage systematic approach which could be employed by global south countries for designing ANN load forecasting models with the aim of simplifying the design process. While the results of this work demonstrate that PV is a suitable energy source for countries like Myanmar, they also point to the importance of including annual load increase rate and PV output degradation rate in system planning. Full article

The design methodologies and part shape algorithms for additive manufacturing (AM) are rapidly growing fields, proven to be of critical importance for the uptake of additive manufacturing of parts with enhanced performance in all major industrial sectors. The current trend for part design is a computationally driven approach where the parts are algorithmically morphed to meet the functional requirements with optimized performance in terms of material distribution. However, the manufacturability restrictions of AM processes are not considered at the primary design phases but at a later post-morphed stage of the part’s design. This paper proposes an AM design method to ensure: (1) optimized material distribution based on the load case and (2) the part’s manufacturability. The buildability restrictions from the direct energy deposition (DED) AM technology were used as input to the AM shaping algorithm to grant high AM manufacturability. The first step of this work was to define the term of AM manufacturability, its effect on AM production, and to propose a framework to estimate the quantified value of AM manufacturability for the given part design. Moreover, an AM design method is proposed, based on the developed internal stresses of the build volume for the load case. Stress tensors are used for the determination of the build orientation and as input for the part morphing. A top-down mesoscale geometric optimization is used to realize the AM part design. The DED Design for Additive Manufacturing (DfAM) rules are used to delimitate the morphing of the part, representing at the same time the freeform mindset of the AM technology. The morphed shape of the part is optimized in terms of topology and AM manufacturability. The topology optimization and AM manufacturability indicator (TMI) is introduced to screen the percentage of design elements that serve topology optimization and the ones that serve AM manufacturability. In the end, a case study for proof of concept is realized. Full article

The buzzword “smart home” promises an intelligent, helpful environment in which technology makes life easier, simpler or safer for its inhabitants. On a technical level, this is currently achieved by many networked devices interacting with each other, working on shared protocols and standards. From a user experience (UX) perspective, however, the interaction with such a collection of devices has become so complex that it currently rather stands in the way of widespread adoption and use. So far, it does not seem likely that a common user interface (UI) concept will emerge as a quasi-standard, as the desktop interface did for graphical UIs. Therefore, our research follows a different approach. Instead of many singular intelligent devices, we envision a UI concept for smart environments that integrates diverse pieces of technology in a coherent mental model of an embodied “room intelligence” (RI). RI will combine smart machinery, mobile robotic arms and mundane physical objects, thereby blurring the line between the physical and the digital world. The present paper describes our vision and emerging research questions and presents the initial steps of technical realization. Full article

Digital transformation is no longer a future trend, as it has become a necessity for businesses to grow and remain competitive in the market. The fourth industrial revolution, called Industry 4.0, is at the heart of this transformation, and is supporting organizations in achieving benefits that were unthinkable a few years ago. The impact of Industry 4.0 enabling technologies in the manufacturing sector is undeniable, and their correct use offers benefits such as improved productivity and asset performance, reduced inefficiencies, lower production and maintenance costs, while enhancing system agility and flexibility. However, organizations have found the move towards digital transformation extremely challenging for several reasons, including a lack of standardized implementation protocols, emphasis on the introduction of new technologies without assessing their role within the business, the compartmentalization of digital initiatives from the rest of the business, and the large-scale implementation of digitalization without a realistic view of return on investment. To instill confidence and reduce the anxiety surrounding Industry 4.0 implementation in the manufacturing sector, this paper presents a conceptual framework based on business process management (BPM). The framework is informed by a content-centric literature review of Industry 4.0 technologies, its design principles, and BPM method. This integrated framework incorporates the factors that are often overlooked during digital transformation and presents a structured methodology that can be employed by manufacturing organizations to facilitate their transition towards Industry 4.0. Full article