Christopher D. Cera

Role-Based Viewing Envelopes for Information Protection in Collaborative Modeling

Information security and assurance are new frontiers for collaborative design. In this context, information assurance (IA) refers to methodologies to protect engineering information by ensuring its availability, confidentiality, integrity, non-repudiation, authentication, access control, etc. In collaborative design, IA techniques are needed to protect intellectual property, establish security privileges and create “need to know” protections on critical features. Aside from 3D watermarking, research on how to provide IA to distributed collaborative engineering teams is largely non-existent. This paper provides a framework for information assurance within collaborative design, based on a technique we call role-based viewing, in which information security relationships are roles assigned to users based on their permissions and privileges. Role-based viewing is achieved through integration of multi-resolution geometry and with the security model. In this way, 3D models are geometrically partitioned, and the partitioning is used to create multi-resolution mesh hierarchies that obscure, obfuscate, or remove sensitive material from the view of users without appropriate permissions. This approach is the basis for our prototype system FACADE (the Framework for Access-control in Computer-Aided Design Environments), a synchronous, multi-user collaborative modeling environment. In FACADE, groups of users worked in a shared 3D modeling environment in which each user viewing and modeling privileges are managed by a central access control mechanism. In this manner, individual actors see only the data they are allowed to see, at the level of detailed they are permitted to see it.

A collaborative 3D environment for authoring design semantics

This article presents an approach to collaborative authoring of design semantics within a multiuser 3D environment. Our research unites ideas from traditional engineering design with recent work from the Semantic Web and knowledge engineering community. The system we present, Multiuser Groups for Conceptual Understanding and Prototyping (MUG), serves as our research platform. it lets a team of designers-collaborating over the Internet in a shared, multimodal, 3D workspace-model a 3D layout and semantically grounded behavioral description of a product or device.

Redesigning introductory computer programming using multi-level online modules for a mixed audience

We report here on an extensive redesign and unification of the Introductory Computer Programming sequences offered to computer science, computer engineering, information science and digital media majors. The redesign is intended to improve student learning while reducing costs. The approach makes use of substantial Web-based course material and course management tools, including multi-level online modules that individualize instruction and enable students to self-schedule learning each week. Each module covers a particular aspect of computer programming at different levels of knowledge. Students are assigned work and reading from the module at a level appropriate to the objectives of the long-term goals of their major. This allows students in different majors to acquire the appropriate skill level for each technique and concept. Peer mentors and teaching assistants provide assistance online or in person. In the future, we plan to expand the self-scheduling aspect of the course to allow students to enter the course at different modules, depending on their previous knowledge.

Multi-Level modeling and access control for data sharing in collaborative design

This paper presents a method for securing collaborative design using multi-level modeling. When a team of designers works collaboratively on a 3D assembly model, a component of the assembly is presented in a full detail to those who have full access privileges to the component, but in an abstract level of detail to those who have less access privileges. Such various levels of detail can be created in two phases: volumetric feature removal which is achieved through interactive feature recognition on the CAD model, and multi-resolution mesh construction which is based on polygonal simplification. Appropriate representations of the assembly are extracted by direction of access matrix, and then presented to the users participating in collaborative design. The key issues in developing the secure collaborative design system are discussed, and the implementation results are reported.

Academic dishonesty in a high-tech environment

Advances in computing and telecommunication technology provide abundant new opportunities for academic dishonesty. Anecdotal evidence suggests that students are far more aware than faculty of various mechanisms for cheating on exams, plagiarizing assignments, and soliciting work for pay. Fortunately, technological advances also provide the alert instructor with some tools for combating such academic dishonesty.In this session, we will present information on how calculators, cell phones, beepers, and other handheld technology may be used to cheat on exams; how the Internet is used to match students with sources for solutions to their assignments; and existing tools and services for the faculty member.The intention of this session is to inform faculty about various ways that students may commit academic fraud; and tools and approaches that are available to reduce their effectiveness. We also hope to gain further information from other faculty and/or students in attendance. We do not intend to debate whether these activities should be allowed due to the ease with which they are committed, as is often discussed.We will provide a bibliography of articles about high-tech academic dishonesty, software tools and services for detecting plagiarism (including shared code in programming assignments), and Internet resources.

Tools and techniques for large scale grading using Web-based commercial off-the-shelf software

Courseware/Course Management Systems (CMS) such as WebCT or Blackboard are an increasingly popular way to provide a web presence for a course. However, their current web-browser reliance makes it difficult for them to provide functionality that could be useful to computer science instructors. This paper describes our augmentation of a CMS in a large introductory computer science class. It further describes our enhancement of the CMS by clientside software (i.e. residing on the graders computer), written for use by the instructors and graders. Finally, it indicates how conventional CMS architecture can be extended to provide additional functionality that would be desirable for computer science instruction.

Multi-resolution Modeling in Collaborative Design

This paper provides a framework for information assurance within collaborative design, based on a technique we call role-based viewing. Such role-based viewing is achieved through integration of multi-resolution geometry and security models. 3D models are geometrically partitioned, and the partitioning is used to create multi-resolution mesh hierarchies. Extracting an appropriately simplified model suitable for access rights for individual designers within a collaborative design environment is driven by an elaborate access control mechanism.

Hierarchical role-based viewing for secure collaborative CAD

This paper provides a framework for information assurance within collaborative design based on a technique we call rolebased viewing. Role-based viewing enables role-based access control through geometric partitioning of 3D models. The partitioning is used to create variable level-of-detail (LOD) meshes, across both individual parts and assemblies, to provide a model suitable for access rights for individual actors within a collaborative design environment. We show how this technique can be used to implement a hierarchical set of security access privileges based on the BellLa Padula model. The partitioning is derived from a set of access specifications for an assembly model and its parts. The authors believe that this work is the first of its kind in the field of computer-aided design and collaborative engineering.

Conceptual Design Knowledge Management and the Semantic Web

The early stages of engineering design are critical, as the decisions made at this point have the most impact on the final product. However, little software is available to support engineers during the initial, conceptual design phase. In addition, at this and all other stages of design, engineers are increasingly tasked with utilizing unwieldy collections of data such as databases of legacy designs and catalogs. This work addresses both of these issues. A conceptual design interface with several advancements crucial to industrial deployment is developed and used to aid design. Among these are provisions for real-time collaboration and security. A representation of mechanical devices based on intended function is developed and used by the conceptual design interface to capture design semantics. This representation is defined using a description logic, enabling automated reasoning. The descriptions created using the conceptual design interface can thus be employed to annotate designs, create search queries, and to organize collections of designs. Further, this work incorporates Semantic Web technology, enabling conceptual design knowledge to be published and accessed effectively on the World Wide Web. New applications of design repositories are made possible by this but new issues must be investigated and addressed, as discussed here.Copyright

Stochastic microgeometry for displacement mapping

Creating surfaces with intricate small-scale features (microgeometry) and detail is an important task in geometric modeling and computer graphics. We present a model processing method capable of producing a wide variety of complex surface features based on displacement mapping and stochastic geometry. The latter is a branch of mathematics that analyzes and characterizes the statistical properties of spatial structures. The technique has been incorporated into an interactive modeling environment that supports the design of stochastic microgeometries. Additionally a tool has been developed that provides random exploration of the techniques entire parameter space by generating sample microgeometry over a broad range of values. We demonstrate the effectiveness of our technique by creating diverse, complex surface structures for a variety of geometric models, e.g. arrowheads, candy bars, busts, planets and coral.