Bounded Abstract Effects

Effect systems have been a subject of active research for nearly four decades, with the most notable practical example being checked exceptions in programming languages such as Java. While many exception systems support abstraction, aggregation, and hierarchy (e.g., via class declaration and subclassing mechanisms), it is rare to see such expressive power in more generic effect systems. We designed an effect system around the idea of protecting system resources and incorporated our effect system into the Wyvern programming language. Similar to type members, a Wyvern object can have effect members that can abstract lower-level effects, allow for aggregation, and have both lower and upper bounds, providing for a granular effect hierarchy. We argue that Wyvern’s effects capture the right balance of expressiveness and power from the programming language design perspective. We present a full formalization of our effect-system design, showing that it allows reasoning about authority and attenuation. Our approach is evaluated through a security-related case study.

Aerodynamic Optimization of the Sizing and Blade Designs of Hovering Corotating Coaxial Rotors

Corotating coaxial rotors are seeing renewed interest in distributed electric propulsion systems and electric vertical take-off and landing (eVTOL) aircraft. The recent literature reports many interesting investigations, using prescribed rotor blades, into the flow phenomena as well as aerodynamic and aeroacoustic benefits of corotating rotors. However, the subject of the design of blade geometries, optimized to a design goal, for corotating rotors is currently lacking in the literature. This paper is written from such a design perspective, by extending a previous generalized approach to the aerodynamic optimization of counterrotating rotors to corotating rotors. The previous requirement for upper and lower counterrotating rotor torques to be equal can now be lifted in the case of corotating rotors, enabling improved versatility in the optimization of corotating blade designs. The optimization is demonstrated on an application example to address the conflicting conditions that index angles (high) for aeroacoustic benefits of reduced noise are at odds with those (low) for aerodynamic efficiency. The approach demonstrated in this paper is to set the index angle for reduced noise and then recover back the aerodynamic efficiency by using the newly developed aerodynamic optimization technique.

The importance of geotechnical research in building projects: case study sustainable rural housing

When conceiving the project of a building, we understand that it will be interacting with the ground through a "soil-structure" system, and that it will be the appropriate interaction between the ground and the foundation that will guarantee functionality and stability from the geotechnical perspective as structural of the project. Today we identify buildings that present problems concerning structural stability due to a deficient geotechnical study that entails a negative impact from the point of view of safety, functionality and economics of the project. The professional in charge to determine the geotechnical conditions of a site is the Geotechnical Engineer or Engineer specializing in Soil Mechanics, in fact, it must be a professional with comprehensive training with knowledge in various disciplines such as geotechnics, structures, foundations and construction. The document with which we base ourselves to establish the guidelines to follow from an analysis and design perspective is the geotechnical study. This document also allows us to understand the possible threats to which the project will be at some point and how to carry out the analysis and design of the buildings, so that they can interact in perfect harmony with their surroundings. By means of a case study concerning the project of a sustainable rural house, we show the stages and elements that make up the report of the geotechnical study that was carried out, indicating the development, analysis and methodology of the study, as well as the various elements that comprise it.

Exploring Maker Innovation: A Transdisciplinary Engineering Design Perspective

Researchers, designers, and engineers embrace the ongoing maker movement and view ‘grassroots innovation’ as essentially important for staying competitive in both academia and in industry. The research team gives full play to its expertise on innovation and entrepreneurship education. In the past five years of actively participating in the China-U.S. Young Maker Competition, the team coached and worked with over five hundred student makers to create innovative engineering prototypes focusing on the areas of community development, education, environmental protection, health and fitness, energy, transportation, and other areas of sustainable development by combining innovative design and emerging technologies. Several conceptual designs and developments are described. A transdisciplinary engineering design and teaching approach is presented and discussed. Due to the limited time allowed by the competition, more thorough design and development iterations will take place in a future study.

Resistance to Opportunities of Plastic Recycling

Plastics present a vast and pressing issue in modern society. Currently recycling efforts fall dangerously short of dealing with even a small percent of the millions of tons of plastic waste produced yearly across the globe. This article investigates resistance toward plastic recycling in three areas from both a contemporary and a historical context, highlighting the magnitude of the problem and the insufficient nature of current solutions. The three primary areas covered are the plastics problem from (1) a design perspective, (2) a material science perspective, and (3) a systems perspective. Solutions are proposed that emphasize a synergistic collaboration across disciplines and research modes. Ultimately, the conclusions point to a need for stronger engagement at the level of people (both consumers and decision makers) and reintegrating reused and recycled plastics into everyday life to build a solid foundation for success.

Coping With Institutional Complexity and Voids: An Organization Design Perspective for Transnational Interorganizational Projects

This study investigates how transnational interorganizational projects (IOPs) cope with institutional complexity and voids. A case study of a cross-border gas pipeline suggests the coexistence of institutional complexity and voids that amplify collaboration hazards in developing transnational IOPs. Institutional complexity harms the feasibility of a unified form of organizing, whereas institutional voids sabotage the ability of involved organizations to collaborate in a market-based approach. A hybrid organization featured by modular structure, complementary advantages, and system integrator, was designed to navigate complex institutional environments. This study contributes to the project–organization–institution linkage by depicting the impacts of institutions on project organizing.

Designing for others: the roles of narrative and empathy in supporting girls’ engineering engagement

Purpose Science museums provide a context for developing and testing engineering activities that support visitors in creating personally meaningful objects. This study aims to propose that narrative design elements in such engineering activities can foster empathy to support engineering engagement among girls ages 7–14. Design/methodology/approach Taking a constructionist approach to engineering design, the authors present results from an observational study (n = 202 girls) of engineering activities across three museums that were designed to foster girls’ engineering engagement by integrating narrative elements aimed to foster empathy in activities. Using quantitative counts from observation protocols, the authors conducted statistical analyses to explore relationships between narrative, engineering and empathy. Findings Linear regression demonstrated a statistically significant relationship between empathy and increased numbers of engineering practices within museum activities. Additionally, this led us to explore the impacts the potential narrative design elements may have on designing for empathy – multiple linear regressions found both narrative and empathy to be independently associated with engineering practices. Overall, the authors found that using narrative to design activities to elicit empathy resulted in girls demonstrating more engineering practices. Originality/value The authors offer design ideas to foster aspects of empathy, including user-centered design, perspective-taking, familiarity and desire to help.

Examining the Transition towards the Supply of Sustainable Apartments in Australia: A Design Perspective

The built environment in Australia accounts for about 25% of total greenhouse gas emissions (GHG), where only the multi-unit residential buildings account for a quarter of these emissions. Moving towards sustainable constructions and green buildings can help in reducing GHG emissions and their negative effects. In this context, integrating Circular Economy (CE) principles into buildings’ projects can further help in reducing the environmental impact of the building stock. The purpose of this research is to explore the embracing of CE in the apartment industry. Personal experiences and perspectives of 5 stakeholders from Vitoria and NSW involving sustainable new and retrofit apartment buildings are investigated by drawing on the results of the semi-structured interview. Results underlined barriers and opportunities for designing sustainable apartments.