The logic of typed feature structures is a sorted description logic that has enjoyed widespread usage in grammar design for the last 20 years. Woodbury and Burrow have faithfully preserved its strengths in adapting it to design space navigation research, although the weaknesses it has exhibited in the context of natural language grammar design are likely to surface here as well.

In this work, an artificial neural network model is established to understand the relationship among the tensile properties of as-printed Ti6Al4V parts, annealing parameters, and the tensile properties of annealed Ti6Al4V parts. The database was established by collecting published reports on the annealing treatment of selective laser melting (SLM) Ti6Al4V, from 2006 to 2020. Using the established model, it is possible to prescribe annealing parameters and predict properties after annealing for SLM Ti-6Al-4V parts with high confidence. The model shows high accuracy in the prediction of yield strength (YS) and ultimate tensile strength (UTS). It is found that the YS and UTS are sensitive to the annealing parameters, including temperature and holding time. The YS and UTS are also sensitive to initial YS and UTS of as-printed parts. The model suggests that an annealing process of the holding time of fewer than 4 h and the holding temperature lower than 850°C is desirable for as-printed Ti6Al4V parts to reach the YS required by the ASTM standard. By studying the collected data of microstructure and tensile properties of annealed Ti6Al4V, a new Hall-Petch relationship is proposed to correlate grain size and YS for annealed SLM Ti6Al4V parts in this work. The prediction of strain to failure shows lower accuracy compared with the predictions of YS and UTS due to the large scattering of the experimental data collected from the published reports.

This paper presents a preliminary study into the spatial features that can be used to distinguish creativity andefficiency in design layouts, and the distinct pattern of cognitive and metacognitive activity that is associated with creative design. In a design experiment, a group of 12 architects were handed a design brief. Their drawing activity was recorded and they were required to externalize their thoughts during the design process. Both design solutions and verbal comments were analysed and modelled. A separate group of experienced architects used their expert knowledge to assign creativity and efficiency scores to the 12 design solutions. The design solutions were evaluated spatially. Protocol analysis studies including linkography and macroscopic analysis were used to discern distinctive patterns in the cognitive and metacognition activity of designs marked with the highest and least creativity scores. Entropy models of the linkographs and knowledge graphs were further introduced Finally, we assessed how creativity and efficiency correlates to experiment variables, cognitive activity, metacognitive activity, spatial and functional distribution of spaces in the design solutions, and the number and type of design constraints applied through the course of design. Through this investigation, we suggest that expert knowledge can be used to assess creativity and efficiency in designs. Our findings indicate that efficient layouts have distinct spatial features, and that cognitive and metacognitive activity in design that yields a highly creative outcome corresponds to higher frequencies of design moves and higher linkages between design moves.

Cyber–physical–social systems (CPSS) are physical devices that are embedded in human society and possess highly integrated functionalities of sensing, computing, communication, and control. CPSS rely on their intense collaboration and information sharing through networks to be functioning. In this paper, topology-informed network information dynamics models are proposed to characterize the evolution of information processing capabilities of CPSS nodes in networks. The models are based on a mesoscale probabilistic graph model, where the sensing and computing capabilities of the nodes are captured as the probabilities of correct predictions. A topology-informed vector autoregression model and a latent variable vector autoregression model are proposed to model the correlations between prediction capabilities of nodes as linear functional relationships. A hybrid Gaussian process regression model is also developed to capture both the nonlinear spatial and temporal correlations between nodes. The new information dynamics models are demonstrated and tested with a simulator of CPSS networks. The results show that the topological information of networks can improve the efficiency in constructing the time series models. The network topology also has influences on the prediction capabilities of CPSS.

This paper describes an application of artificial intelligence to support software reuse. We begin by discussing the characteristics of software engineering that establish dynamic reorganization as a requirement for a repository of software artifacts. We then present an experimental system that uses incremental concept formation as the basis for dynamic reorganization, and the conceptual hierarchy that was generated by the system for a set of 67 artifacts. The hierarchy is compared to a hierarchy produced manually by independent investigators, and the automatic hierarchy is evaluated in terms of retrieval efficiency and retrieval reliability. The paper ends with a discussion of three projects that share similar objectives with our work.

Assembly optimization of printed circuit boards (PCBs) has received considerable research attention because of efforts to improve productivity. Researchers have simplified complexities associated with PCB assembly; however, they have overlooked hardware constraints, such as pick-and-place restrictions and simultaneous pickup restrictions. In this study, a hybrid group search optimizer (HGSO) was proposed. Assembly optimization of PCBs for a multihead placement machine is segmented into three problems: the (1) auto nozzle changer (ANC) assembly problem, (2) nozzle setup problem, and (3) component pick-and-place sequence problem. The proposed HGSO proportionally applies a modified group search optimizer (MGSO), random-key integer programming, and assigned number of nozzles to an ANC to solve the component picking problem and minimize the number of nozzle changes, and the place order is treated as a traveling salesman problem. Nearest neighbor search is used to generate an initial place order, which is then improved using a 2-opt method, where chaos local search and a population manager improve efficiency and population diversity to minimize total assembly time. To evaluate the performance of the proposed HGSO, real-time PCB data from a plant were examined and compared with data obtained by an onsite engineer and from other related studies. The results revealed that the proposed HGSO has the lowest total assembly time, and it can be widely employed in general multihead placement machines.

To specify realistic tolerances and ensure acceptable product yields, a product development team must take into account the current process capability of the factory. Using historical process capability data in product development is frequently discussed in academic and industry literature. However, while many organizations have databases, the use of historical data in design is limited. This paper addresses the technical challenges of implementing a producibility analysis tool. First, a description of how data is currently collected and recorded is given. Second, the infeasibility of a “just-press-a-button” system for checking producibility is described. Finally, a new paradigm for data access is proposed, implemented in software, and tested on data used by industry.

It is known that wherever there is human interaction, there is social influence. Here, we refer to more influential individuals as “influencers”, who drive team processes for better or worst. Social influence gives rise to social learning, the propensity of humans to mimic the most influential individuals. As individual learning is affected by the presence of an influencer, so is an individual's idea generation . Examining this phenomenon through a series of human studies would require an enormous amount of time to study both individual and team behaviors that affect design outcomes. Hence, this paper provides an agent-based approach to study the effect of influencers during idea generation. This model is supported by the results of two empirical experiments which validate the assumptions and sustain the logic implemented in the model. The results of the model simulation make it possible to examine the impact of influencers on design outcomes, assessed in the form of exploration of design solution space and quality of the solution. The results show that teams with a few prominent influencers generate solutions with limited diversity. Moreover, during idea generation, the behavior of the teams with uniform distribution of influence is regulated by their team members' self-efficacy.

Computer-aided process planning has been recognized as an important tool for coordinating the different operations involved in making the product. While temporal knowledge is central to the design of efficient and reliable process plans, little attention is given to the integration of process planning and temporal processing and reasoning. To fill the void, we propose in this paper a practical approach, which is inspired by the framework of Temporal Constraint Satisfaction Problem (TCSP), to integrate process planning and temporal reasoning. We show that a TCSP formulation is a subset of a formulation using a reified temporal logic, and discuss the advantages of using such a restricted model. To reflect more realistic process planning encountered in real manufacturing environments, we present a model, called n-TCSP, which is a generalization of the TCSP framework. We envision the proposed temporal reasoning framework as one of the modules in the evolving new intelligent computer-aided process planning.

Over the past 20 years I have focused on the synthesis process, the process of creation, of bringing together ideas and objects to fulfill and enable needs. Synthesis is a core engineering activity, the partner in the design and analysis cycle of engineering (and other) design. Synthesis is the basis of innovation, the enabler of creating that which is new. Over the past 20 years, research and practice in the area of synthesis and innovation has become more intricate, more complex, and more complete in its breadth of exploration and depth of understanding and delivery. Research in the area that was started over the past 10 to 20 years is now being commercialized, beginning to impact the way design is practiced. The state of the art of algorithms, theories, and processes for the computing basis of synthesis research today can be found in Formal Engineering Design Synthesis (Antonsson & Cagan, 2001). This discussion is not a review of the literature or state of the art, but rather my views of the field of innovation, its emergence into a scientific study, areas of focus for future research, and some of my experiences in each of these areas.

Design rationale should be regarded both as a tool for the practice of design, and as a method to enable the science of design. Design rationale answers questions about why a given design takes the form that it does. Answers to these why questions represent a significant portion of the knowledge generated from design research. This knowledge, along with that from empirical studies of designs in use, contributes to what Simon called the sciences of the artificial. Most research on the nature and use of design rationale has been analytic or theoretical. In this article, we describe an empirical study of the roles that design rationale can play in the conduct of design research. We report results from an interview study with 16 design researchers investigating how they construe and carry out design as research. The results include an integrated framework of the affordances design rationale can contribute to design research. The framework and supporting qualitative data provide insight into how design rationale might be more effectively leveraged as a first-class methodology for research into the creation and use of artifacts.

Searching for information is an ubiquitous need in today's data-oriented environments. However, a request for search often entails the service and cooperation of tools managing a diversified set of tasks. In this article, we explore how tools in the form of cooperating agents can be deployed for information management. We describe an agent framework called GAME (goal-oriented, agent-managed environment), and focus on how GAME agents search cooperatively for information requested by a user. Cooperative search entails several issues such as coordinating agent activities, maintaining transparency to agent heterogeneity, and designing information formats to be shared among the agents that require examination. This article analyzes these issues and describes how they are handled in the GAME framework. Cooperative search effectively supports collaboration and information sharing not only among agents in a domain, but also among GAME agents developed across domains. We illustrate the application of cooperative search in task-oriented domains such as Manufacturing and Front Office showing how GAME promotes intradomain and interdomain collaboration in a Factory environment.

Automatically extracting knowledge from small datasets with a valid causal ordering is a challenge for current state-of-the-art methods in machine learning. Extracting other type of knowledge is important but challenging for multiple engineering fields where data are scarce and difficult to collect. This research aims to address this problem by presenting a machine learning-based modeling framework leveraging the knowledge available in fundamental units of the variables recorded from data samples, to develop parsimonious, explainable, and graph-based simulation models during the early design stages. The developed approach is exemplified using an engineering design case study of a spherical body moving in a fluid. For the system of interest, two types of intricated models are generated by (1) using an automated selection of variables from datasets and (2) combining the automated extraction with supplementary knowledge about functions and dimensional homogeneity associated with the variables of the system. The effect of design, data, model, and simulation specifications on model fidelity are investigated. The study discusses the interrelationships between fidelity levels, variables, functions, and the available knowledge. The research contributes to the development of a fidelity measurement theory by presenting the premises of a standardized, modeling approach for transforming data into measurable level of fidelities for the produced models. This research shows that structured model building with a focus on model fidelity can support early design reasoning and decision making using for example the dimensional analysis conceptual modeling (DACM) framework.

Documents are a useful source of expert knowledge in organizations and can be used to foresee, in an earlier stage of a product's life cycle, potential issues and solutions that might occur in later stages of its life cycle. In this research, these stages are, respectively, design and assembly. Even if these documents are available online, it is rather difficult for users to access the knowledge contained in these documents. It is therefore desirable to automatically extract the knowledge contained in these documents and store them in a computer accessible or manipulable form. This paper describes an approach for the first step in this acquisition process: automatically identifying segments of documents that are relevant to aircraft assembly, so that they can be further processed for acquiring expert knowledge. Such identification of relevant segments is necessary for avoiding processing of unrelated information that is costly and possibly distracting for domain relevance. The approach to extracting relevant segments has two steps. The first step is the identification of sentences that form a coherent segment of text, within which the topic does not shift. The second step is to classify segments that are within the topics of interest for knowledge acquisition, that is, aircraft assembly in this instance. These steps filter out segments that are unrelated, and therefore need not be processed for subsequent knowledge acquisition. The steps are implemented by understanding the contents of documents. Using methods of discourse analysis, in particular, discourse representation theory, a list of discourse entities is obtained. The difference in discourse entities between sentences is used to distinguish between segments. The list of discourse entities in a segment is compared against a domain ontology for classification. The implementation and results of validation on sample texts for these steps are described.

The complexity of mechanical design is reflected in the complexity of the design constraints which relate functional requirements to design parameters. Reformulations of the design constraints can significantly reduce this complexity. This is accomplished by a transformation to alternative design parameters, such as a critical ratio, a non-dimensional parameter, or a simple difference; e.g. the ratio of surface area to volume for heat transfer loss, the Reynold's number in fluid mechanics, or the velocity difference across a fluid coupling. We have developed a method by which the alternative parameters are chosen for physical significance and for the ability to create a more direct correspondence to functional behavior as determined by measures of serial and block decomposability of the constraints. Rules have been developed for the creation of physically significant new parameters from the algebraic combination of the original parameters. The rules are based on engineering principles and rely on knowledge about what a parameter physically represents rather than other qualities such as dimensions. A computer based system, called EUDOXUS, has been developed to automate this procedure. The system operates on a set of design constraints to produce sets of transformed constraints in terms of alternative design parameters. The method and its implementation have demonstrated successful results for many highly nonlinear and highly coupled parameterized designs from many mechanical engineering domains.

One of the principal advantages of affordance-based design is that Gibson's theory of affordances is a relational theory, akin to other relational approaches such as relational biology and relational computer science. The relationships between artifacts and their designers and users are of such primary importance that only a theory that is able to deal with those relationships directly appears to be sufficient for describing the wide breadth of problems in engineering design. However, there is no precise definition for what qualifies as a relational theory. In mathematics, we do find something approaching a theory of relations, dating back at least to Charles Peirce's Logic of Relatives around 1870. While rather general, Peirce's ideas on the subject laid the foundation for advances in the 20th century, including the relational model of databases. This paper is a first attempt at applying the mathematics of relations to affordances, with the aim of more precisely characterizing affordances, which heretofore have been difficult to define and, lacking appropriate mathematics, nearly impossible to subject to computation. Meanwhile, the implicit computability of affordances as relations is demonstrated by examples drawn from engineering, physics, computer science, biology, and architecture.

Having no fundamental difficulties with Woodbury and Burrow's article, I explore some implications of their work based on my experience, and that of PhD students advised by me, with developing design support systems. I suggest that such systems need a distinct task layer on top of the computational layer, where the power of a system rests. I also express unease with some details of the article under review, in the hope of contributing to a wider discussion.