Browsing by Author "Bairaktarova, Diana"
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- Active Suspension Design Requirements for Compliant Boundary Condition Road DisturbancesSrinivasan, Anirudh (Virginia Tech, 2017-09-05)The aim of suspension systems in vehicles is to provide the best balance between ride and handling depending on the operating conditions of a vehicle. Active suspensions are far more effective over a variety of different road conditions compared to passive suspension systems. This is because of their ability to store and dissipate energy at different rates. Additionally, they can even provide energy of their own into the rest of the system. This makes active suspension systems an important topic of research in suspension systems. The biggest benefit of having an active suspension system is to be able to provide energy into the system that can minimize the response of the sprung mass. This is done using actuators. Actuator design in vehicle suspension system is an important research topic and a lot of work has been done in the field but little work has been done to estimate the peak control force and bandwidth required to minimize the response of the sprung mass. These two are very important requirements for actuator design in active suspensions. The aim of this study is estimate the peak control force and bandwidth to minimize the acceleration of the sprung mass of a vehicle while it is moving on a compliant surface. This makes the road surface a bi-lateral boundary and hence, the total system is a combination of the vehicle and the compliant road. Generalized vehicle and compliant road models are created so that parameters can be easily changed for different types of vehicles and different road conditions. The peak control force is estimated using adaptive filtering. A least mean squares (LMS) algorithm is used in the process. A case study with fixed parameters is used to show the results of the estimation process. The results show the effectiveness of an adaptive LMS algorithm for such an application. The peak control force and the bandwidth that are obtained from this process can then be used in actuator design.
- A Case Study on Atmospheric Flight Mechanics Conceptual UnderstandingMartinez Soto, Karen Dinora (Virginia Tech, 2024-05-13)Atmospheric Flight Mechanics (AFM) is one of the cornerstones of aeronautical engineering and includes subjects like aerodynamic prediction, stability and control, dynamics, and vehicle design. These topics are critical to the success of aircraft development, so AFM is considered one of the most important foundational knowledge areas for aerospace engineering. Unfortunately, students graduating from aerospace engineering programs are often underprepared to perform in AFM jobs. This ongoing research focuses on developing a blueprint for assessing conceptual understanding of AFM concepts. Since existing literature suggests that novices and experts organize knowledge differently, comparing students' and experts' mental models can shine a light on the alternative conceptions that students retain post-instruction. As such, framing the study around synthetic mental models can be advantageous. To explore these mental models, three types of data have been collected and analyzed. Document analysis was done on course documents to identify what concept relationships were being presented to the students. Class observations were conducted to analyze how concepts are introduced to students and what relationships are highlighted by the instructor. Finally, a concept mapping activity was facilitated to study the mental models that the students built after instruction. The results show a lack of synthetization between the knowledge introduced in the classroom and students' prior knowledge which translated into student mental models that do not meet some of the expectations of the course. Moreover, this study highlights the importance of the instructor's awareness of their own expectations for learning and knowledge synthetization in the design of an AFM course.
- Design, Analysis and Fabrication of Complex Structures using Voxel-based modeling for Additive ManufacturingTedia, Saish (Virginia Tech, 2017-11-20)A key advantage of Additive Manufacturing (AM) is the opportunity to design and fabricate complex structures that cannot be made via traditional means. However, this potential is significantly constrained by the use of a facet-based geometry representation (e.g., the STL and the AMF file formats); which do not contain any volumetric information and often, designing/slicing/printing complex geometries exceeds the computational power available to the designer and the AM system itself. To enable efficient design and fabrication of complex/multi-material complex structures, several algorithms are presented that represent and process solid models as a set of voxels (three-dimensional pixels). Through this, one is able to efficiently realize parts featuring complex geometries and functionally graded materials. This thesis specifically aims to explore applications in three distinct fields namely, (i) Design for AM, (ii) Design for Manufacturing (DFM) education, and (iii) Reverse engineering from imaging data wherein voxel-based representations have proven to be superior to the traditional AM digital workflow. The advantages demonstrated in this study cannot be easily achieved using traditional AM workflows, and hence this work emphasizes the need for development of new voxel based frameworks and systems to fully utilize the capabilities of AM.
- Development of CAD Platform Independent Software for Automatic Grading of Technical DrawingsIngale, Sanchit Sanjay (Virginia Tech, 2017-09-15)Spatial visualization is the ability of an individual to visualize an object mentally and understand its spatial orientation. It plays an important role in engineering. There have been multiple works that show that spatial visualization skills can be improved with the right training. Creating technical drawings requires mental manipulation and visual thinking. Strong spatial visualization abilities are required for such a mental process. To train students in this process and to improve their spatial skills, Professor Diana Bairaktarova conducted a class in spatial visualization for freshmen in engineering at Virginia Polytechnic Institute and State University. The class consisted of 169 students from different engineering disciplines. One of the major pedagogical techniques used in the class was to give students three assignments on drawing sectional views of mechanical objects with a pre-defined cutting plane. All three assignments had the same six mechanical objects to assess their improvement through the class. Students were not given feedback after completion of each assignment. They were asked to do the first assignment at the beginning of the course, the second assignment during the middle of the semester and the final assignment towards the end of the semester. The students were given instructions on how to draw the 2D sectional views. The assignments were then graded by the teaching assistants for the class and the improvement of the students through the semester was recorded. Assignments were graded manually by two different raters using a pre-defined grading rubric. An inter-rater reliability was established between the graders. There were drawbacks to this process. It was extremely time consuming since there were more than 500 assignments to be graded by the teaching assistants. Also, to establish inter-rater reliability, the assignments had to be graded twice. The process would have been more efficient if there was a software that could automate the grading process. Also, this would eliminate the need to establish an inter-rater reliability. This research aims at developing a software for automatic grading of the technical drawings. The software gives students' feedback on the drawings describing their mistakes. This would give a more complete learning experience as the students would get a better understanding of the internal details of the object with the help of the feedback they are getting. In addition, the software is independent of the CAD platform used to create the drawings. The instructor can also upload a batch of images that can be processed by the software at once. The grading rubric that was used for manual grading can be implemented in the software. The software uses Image processing and Computer Vision toolboxes in MATLAB which enables the comparison between the submitted technical drawing and the source (solution) drawing. The software is currently developed for simple geometries with less complicated features as it is being employed in a course where students are new to CAD environment. Students can also use this software as an interactive learning tool as they create 3D models and sectional views of mechanical objects. The proposed software reduces the amount of effort put in by faculty on grading the assignments. It also gives students feedback on the drawings, making it an interactive tool which improves the learning experience. This software can be a powerful pedagogical tool to improve spatial visualization skills.
- Engineering Student's Ethical Awareness and Behavior: A New Motivational ModelBairaktarova, Diana; Woodcock, Anna (2017-08)Professional communities are experiencing scandals involving unethical and illegal practices daily. Yet it should not take a national major structure failure to highlight the importance of ethical awareness and behavior, or the need for the development and practice of ethical behavior in engineering students. Development of ethical behavior skills in future engineers is a key competency for engineering schools as ethical behavior is a part of the professional identity and practice of engineers. While engineering educators have somewhat established instructional methods to teach engineering ethics, they still rely heavily on teaching ethical awareness, and pay little attention to how well ethical awareness predicts ethical behavior. However the ability to exercise ethical judgement does not mean that students are ethically educated or likely to behave in an ethical manner. This paper argues measuring ethical judgment is insufficient for evaluating the teaching of engineering ethics, because ethical awareness has not been demonstrated to translate into ethical behavior. The focus of this paper is to propose a model that correlates with both, ethical awareness and ethical behavior. This model integrates the theory of planned behavior, person and thing orientation, and spheres of control. Applying this model will allow educators to build confidence and trust in their students' ability to build a professional identity and be prepared for the engineering profession and practice.
- Exploring Engineering Faculty Experiences and Networks in Integrating Ethics Education: Insights from a University-Wide Curriculum ReformSnyder, Samuel Aaron (Virginia Tech, 2024-06-04)In today's globalized and technology-driven landscape, engineers wield unprecedented influence. As a response to calls from engineering accrediting and professional organizations, engineering educators have begun to further emphasize the importance of ethical decision-making within the curriculum. However, despite numerous attempts to integrate ethics, there remains a lack of consensus on effective strategies, particularly for larger-scale initiatives. This research, utilizing Lattuca and Stark's (2009) Academic Plan model, explores the Pathways curriculum reform at Virginia Tech, a university-wide initiative aimed at integrating intercultural awareness and ethical reasoning across general education courses. Through a case study methodology, semi-structured interviews were conducted with 12 faculty in the College of Engineering. Participants shared insights on the barriers encountered, resources utilized, and perceptions of ethical culture within their various academic environments. Additionally, participants described their network interactions within and beyond the curriculum reform initiative. Findings suggest faculty leverage existing networks during curriculum reform, with identified barriers categorized as influence-driven and resource-driven. Integrating these insights into the Academic Plan model offers a nuanced, process-oriented understanding of curricular change.
- Exploring Students’ Experiences with Mindfulness Meditations in a First-Year General Engineering CourseMartini, Larkin; Huerta, Mark Vincent; Jurkiewicz, Jazmin; Chan, Brian; Bairaktarova, Diana (MDPI, 2024-05-29)With growing mental health concerns among college students, they need to effectively develop skills to alleviate stress amidst the demands of university life. Teaching mindfulness skills to engineering students early in their programs, such as during introductory courses, may provide students with the tools they need to effectively cope with academic stressors, support well-being, and mitigate mental health concerns. This study aimed to understand the variation in experiences of engineering students who participated in weekly mindfulness meditation during a first-year cornerstone engineering course. This study used a thematic analysis approach to analyze students’ in-class, weekly reflections from eight meditation exercises across two course sections. The frequency of codes and themes were then analyzed across meditation types to identify trends in student experiences. Our results show that the most common student experience from engaging in mindfulness meditation was feeling less stressed, calmer, and more relaxed. Other positive experiences include feeling more energized and focused. Some students, however, did report some negative experiences, such as distress and tiredness. The Dynamic Breathing exercise, in particular, showed higher rates of negative experiences than other meditation types. The results also demonstrate that different types of meditations produce different student experiences. Meditation exercises with open monitoring components showed higher rates of insight/awareness and difficulty focusing attention than focused attention meditations. These findings indicate that utilizing weekly mindfulness exercises in introductory engineering courses can benefit students’ overall mental health and well-being when adequately implemented.
- Impact of Interactive Holographic Learning Environment for bridging Technical Skill Gaps of Future Smart Construction Engineering and Management StudentsOgunseiju, Omobolanle Ruth (Virginia Tech, 2022-07-25)The growth in the adoption of sensing technologies in the construction industry has triggered the need for graduating construction engineering students equipped with the necessary skills for deploying the technologies. For construction engineering students to acquire technical skills for implementing sensing technologies, it is pertinent to engage them in hands-on learning with the technologies. However, limited opportunities for hands-on learning experiences on construction sites and in some cases, high upfront costs of acquiring sensing technologies are encumbrances to equipping construction engineering students with the required technical skills. Inspired by opportunities offered by mixed reality, this study presents an interactive holographic learning environment that can afford learners an experiential opportunity to acquire competencies for implementing sensing systems on construction projects. Firstly, this study explores the required competencies for deploying sensing technologies on construction projects. The current state of sensing technologies in the industry and sensing technology education in construction engineering and management programs were investigated. The learning contents of the holographic learning environment were then driven by the identified competencies. Afterwards, a learnability study was conducted with industry practitioners already adopting sensing technologies to assess the learning environment. Feedback from the learnability study was implemented to further improve the learning environment after which a usability evaluation was conducted. To investigate the pedagogical value of the learning environment in construction education, a summative evaluation was conducted with construction engineering students. This research contributes to the definition of the domain-specific skills required of the future workforce for implementing sensing technologies in the construction industry and how such skills can be developed and enhanced within a mixed reality learning environment. Through concise outline and sequential design of the user interface, this study further revealed that knowledge scaffolding can improve task performance in a holographic learning environment. This study contributes to the body of knowledge by advancing immersive experiential learning discourses previously confined by technology. It opens a new avenue for both researchers and practitioners to further investigate the opportunities offered by mixed reality for future workforce development.
- Mixed reality based environment for learning sensing technology applications in constructionOgunseiju, Omobolanle O.; Akanmu, Abiola A.; Bairaktarova, Diana (2021-11)With the growing rate of adoption of sensing technologies in the construction industry, there is an increased need for technically skilled workforce to successfully deploy these technologies on construction projects. Inspired by opportunities offered by mixed reality, this paper presents the development and evaluation of a holographic learning environment that can afford learners an experiential opportunity to acquire competencies for implementing sensing systems on construction projects. To develop the content of the learning environment, construction industry practitioners and instructors were surveyed, and construction industry case studies on the applications of sensing technologies were explored. Findings of the surveys revealed sensing technologies domain-specific skill gap in the construction industry. Further, the findings informed the requirements of the learning environment. Based on these requirements, key characteristics of the learning environment are identified and employed in designing the environment. Still, a formative evaluation is important for developing an effective mixed reality learning environment for teaching domain-specific competencies. Thus, it is imperative to understand the quality, appropriateness, and representativeness of the content of the learning environment. This paper also presents a learnability assessment of the developed mixed reality learning environment. The assessment was conducted utilizing a focus group discussion with construction industry practitioners. Feedback was sought from the participants regarding the reflectiveness of the layout of the virtual environment of an actual construction site and the appropriateness of the represented construction applications. This study contributes to the definition of the type of domain-specific skills required of the future workforce for implementing sensing technologies in the construction industry and how such skills can be developed and enhanced within a mixed reality learning environment.
- Novel Approach for Computational Modeling of a Non-Premixed Rotating Detonation EngineSubramanian, Sathyanarayanan (Virginia Tech, 2019-07-17)Detonation cycles are identified as an efficient alternative to the Brayton cycles used in power and propulsion applications. Rotating Detonation Engine (RDE) operating on a detonation cycle works by compressing the working fluid across a detonation wave, thereby reducing the number of compressor stages required in the thermodynamic cycle. Numerical analyses of RDEs are flexible in understanding the flow field within the RDE, however, three-dimensional analyses are expensive due to the differences in time-scale required to resolve the combustion process and flow-field. The alternate two-dimensional analyses are generally modeled with perfectly premixed fuel injection and do not capture the effects of improper mixing arising due to discrete injection of fuel and oxidizer into the chamber. To model realistic injection in a 2-D analysis, the current work uses an approach in which, a Probability Density Function (PDF) of the fuel mass fraction at the chamber inlet is extracted from a 3-D, cold-flow simulation and is used as an inlet boundary condition for fuel mass fraction in the 2-D analysis. The 2-D simulation requires only 0.4% of the CPU hours for one revolution of the detonation compared to an equivalent 3-D simulation. Using this method, a perfectly premixed RDE is comparing with a non-premixed case. The performance is found to vary between the two cases. The mean detonation velocities, time-averaged static pressure profiles are found to be similar between the two cases, while the local detonation velocities and peak pressure values vary in the non-premixed case due to local pockets fuel rich/lean mixtures. The mean detonation cell sizes are similar, but the distribution in the non-premixed case is closer due to stronger shock structures. An analytical method is used to check the effects of fuel-product stratification and heat loss from the RDE and these effects adversely affect the local detonation velocity. Overall, this method of modeling captures the complex physics in an RDE with the advantage of reduced computational cost and therefore can be used for design and diagnostic purposes.
- Person or thing oriented: A comparative study of individual differences of first-year engineering students and practitionersBairaktarova, Diana; Pilotte, Mary K. (2020-02-07)Background: Engineering practice is meant to advance the human condition, yet curricula do not appear to fully promote the human-centered philosophy of engineering in implementation. The educational system may inadvertently signal to students that engineering is a career choice better suited for those preferring to work with things rather than people. This framing of the profession prompts questions regarding student interests when compared to those of practicing engineers and how such interests become concrete through education and introduction into the profession. Purpose/Hypothesis: We compare engineering students' and practitioners' interest in working with people or things in their environment. We examine gender differences for each sample. Design/Methods: Multiple analysis of variance was used to examine the samples of practicing engineers (n = 339) and first-year engineering students (n = 383). A multiple-group confirmatory factor analysis provides evidence of measurement invariance and justifies the use of the person-thing orientation (PO-TO) scale structure for both samples. Results: Detailed PO values reveal that students' PO scores (n = 383, M = 3.313) are more than one and a half points lower than practicing engineer counterparts examined (n = 339, M = 4.836). However, no significant difference between practicing engineers and students was found for TO. Further, statistically significant differences in PO and TO were found between male and female participants within both samples, students and practicing engineers. Conclusions: Differences detected in PO and TO across the samples suggest possible environmental factors influencing student perspectives of the engineering profession. This condition may inadvertently discourage more diverse students from pursuing engineering.
- Predicting Spatial Visualization Problems’ Difficulty Level from Eye-Tracking DataLi, Xiang; Younes, Rabih; Bairaktarova, Diana; Guo, Qi (MDPI, 2020-03-31)The difficulty level of learning tasks is a concern that often needs to be considered in the teaching process. Teachers usually dynamically adjust the difficulty of exercises according to the prior knowledge and abilities of students to achieve better teaching results. In e-learning, because there is no teacher involvement, it often happens that the difficulty of the tasks is beyond the ability of the students. In attempts to solve this problem, several researchers investigated the problem-solving process by using eye-tracking data. However, although most e-learning exercises use the form of filling in blanks and choosing questions, in previous works, research focused on building cognitive models from eye-tracking data collected from flexible problem forms, which may lead to impractical results. In this paper, we build models to predict the difficulty level of spatial visualization problems from eye-tracking data collected from multiple-choice questions. We use eye-tracking and machine learning to investigate (1) the difference of eye movement among questions from different difficulty levels and (2) the possibility of predicting the difficulty level of problems from eye-tracking data. Our models resulted in an average accuracy of 87.60% on eye-tracking data of questions that the classifier has seen before and an average of 72.87% on questions that the classifier has not yet seen. The results confirmed that eye movement, especially fixation duration, contains essential information on the difficulty of the questions and it is sufficient to build machine-learning-based models to predict difficulty level.
- Transdisciplinarity on Paper: How do interdisciplinary faculty translate university initiatives into the classroom?Ozkan, Desen Sevi (Virginia Tech, 2020-06-24)University-level transdisciplinary initiatives have become prevalent as institutions reorient disciplines around complex problems that are relevant to society. Transdisciplinary research initiatives, like those of interdisciplinarity in the previous decade, are reinforced by federal funding agencies because of their potential to yield technological innovation, and in turn, economic growth. However, the sustained development of transdisciplinary or interdisciplinary curriculum design remains limited due to the multiple competing factors that govern the curriculum. This dissertation research focuses on the implementation of the transdisciplinary initiative as it pertains to interdisciplinary curriculum design. I use public institutional documents to trace the transdisciplinary institutional initiative as it is enacted at different university levels and interviews to understand the initiatives in practice, drawing from administrators, faculty, and staff experiences as they develop interdisciplinary courses. Many university-level initiatives that purport transdisciplinary and interdisciplinary education fall short in their implementation because of academic structures that directly or indirectly inhibit sustainable interdisciplinary curricula. Instead, administrative organizations like the Registrar's Office, Office of Integrated General Education, and Transdisciplinary Initiative Office develop networks and artifacts that connect faculty who have experience bypassing academic structures with faculty who seek out these forms of institutional support. These emergent practices are an adaptation to the university system rather than a proactive measure that facilitates the large-scale structural change claimed by university-level transdisciplinary initiatives. This study contributes to the understanding of potential long-term implications through the examination of interrelated university initiatives as they exist through metrics and incentives provided by the upper administration and experiences of faculty and staff in developing interdisciplinary courses.
- Understanding Empathy in the Experiences of Undergraduate Engineering Students in Service-Learning ProgramsYeaman, Adetoun Oludara (Virginia Tech, 2020-06-17)In an increasingly globalized world and with rapid advancement in technology, there is a need to grapple more intently with social implications of engineering and technology. In the engineering community, these trends direct us to more critically consider how engineering and technology affect humanity and to interact effectively in diverse populations. Empathy, an ability that is central to the process of understanding and considering others, has been recognized as a valuable competency in the education of engineers. In engineering education specifically, several studies have pursued definition of empathy in the engineering context and its importance in engineering curriculum. Studies suggest that service learning is a useful pedagogical approach for supporting students in the development of social competencies, including empathy. However, it is not clear how this development happens. In this dissertation, I sought to understand engineering students' experiences in a service-learning context to learn the ways in which empathy emerged in their descriptions and the elements of participants' experiences that shaped their empathy development. My participants were fourteen engineering students from two institutions, a small private university and a large public university, with both groups involved in at least one-semester of a service-learning course. I describe my phenomenological approach to this investigation and share my findings. Notably, I found eight main themes in my investigation of the role of empathy within the service-learning experiences described namely: changing perspective about others, having a sense of responsibility to others, keeping an open mind, inquiring of stakeholders, seeing others' points of view, understanding others' situations, being able to adjust goals and compromise and recognizing and/or welcoming difference. Additionally, I found both elements of participants' experiences designed into the course and those that were unprecedented relevant in shaping their empathy development. I also discuss the implications of these findings for engineering education and practice.
- Understanding the Relationships Between Disability, Engineering, and the Design of Engineering Course Websites Through Disabled Engineering Students' PerspectivesSpingola, Elizabeth Marie (Virginia Tech, 2020-04-15)This dissertation examines the culture and climate of disabled people and the disability community within society and the engineering field and the experience of disabled students in higher education. The theoretical lenses utilized is the Technology Acceptance Model which emphasizes the importance of end user's perspectives, and the Social Model of Disability which sees the world and society as disabling rather than the imposition of disability on a person. The perception of disability in engineering is examined through the use of a systematic literature review within Chapter 3 by comparing general engineering academic literature and engineering education literature housed within the American Society of Engineering Education national database. Chapter 4 of this dissertation quantitatively examines the digital accessibility landscape of learning management systems utilized within engineering and engineering related courses that first and second year engineering students are required to take. Finally, Chapter 5 utilized a mixed method approach to examine disabled and non-disabled engineering students' perspectives on the usability of their Learning Management System within their engineering courses. The second part of this research study utilizes individual design interviews to have students redesign their Canvas experiences such that it minimizes digital accessibility barriers. Chapter 6 details tangible digital accessibility recommendations for developers, designers, and instructors/content managers. These recommendations are based on the results within the previous chapters of this dissertation.
- Using eye gaze to reveal cognitive processes and strategies of engineering students when solving spatial rotation and mental cutting tasksHsing, Hsiang-Wen; Bairaktarova, Diana; Lau, Nathan (American Society for Engineering Education, 2023-01)Background: Spatial problem-solving is an essential skill for success in many engineering disciplines; thus, understanding the cognitive processes involved could help inform the design of training interventions for students trying to improve this skill. Prior research has yet to investigate the differences in cognitive processes between spatial tasks in problem-solving to offer learners timely feedback. Purpose/Hypothesis: In this study, we investigated how different spatial tasks change the cognitive processes and problem-solving strategies used by engineering students with low spatial ability. Design/Method: Study participants completed mental rotation and mental cutting tasks of high and low difficulty. Eye-tracking data were collected and categorized as encoding, transformation, and confirmation cognitive processes. The adoption of either a holistic or piecemeal strategy and response accuracy were also measured. Results: Mental rotation was found to have a higher number of fixations for each cognitive process than the mental cutting task. The holistic strategy was used in both difficulty levels of the mental cutting task, while the piecemeal strategy was adopted for the mental rotation task at a high difficulty level. Only encoding fixations were significantly correlated with accuracy and most strongly correlated with strategy. Conclusion: Encoding is an important cognitive process that could affect subsequent cognitive processes and strategies and could, thus, play an important role in performance. Future development in spatial training should consider how to enhance encoding to aid students with low spatial ability. Educators can utilize gaze metrics and empirical research to provide tailored and timely feedback to learners.
- ViTA: A flexible CAD-tool-independent automatic grading platform for two-dimensional CAD drawingsYounes, Rabih; Bairaktarova, Diana (SAGE, 2022-01-01)Grading engineering drawings takes a significant amount of an instructor’s time, especially in large classrooms. In many cases, teaching assistants help with grading, adding levels of inconsistency and unfairness. To help in grading automation of CAD drawings, this paper introduces a novel tool that can completely automate the grading process after students submit their work. The introduced tool, called Virtual Teaching Assistant (ViTA), is a CAD-tool-independent platform that can work with exported drawings originating from different CAD software having different export settings. Using computer vision techniques applied to exported images of the drawings, ViTA can not only recognize whether or not a two-dimensional (2 D) drawing is correct, but also offers the detection of many important orthographic and sectional view mistakes such as mistakes in structural features, outline, hatching, orientation, scale, line thickness, colors, and views. We show ViTA’s accuracy and its relevance in the automated grading of 2 D CAD drawings by evaluating it using 500 student drawings created with three different CAD software.