Kiju Lee

Assessment in and of serious games: an overview

There is a consensus that serious games have a significant potential as a tool for instruction. However, their effectiveness in terms of learning outcomes is still understudied mainly due to the complexity involved in assessing intangible measures. A systematic approach--based on established principles and guidelines--is necessary to enhance the design of serious games, and many studies lack a rigorous assessment. An important aspect in the evaluation of serious games, like other educational tools, is user performance assessment. This is an important area of exploration because serious games are intended to evaluate the learning progress as well as the outcomes. This also emphasizes the importance of providing appropriate feedback to the player. Moreover, performance assessment enables adaptivity and personalization to meet individual needs in various aspects, such as learning styles, information provision rates, feedback, and so forth. This paper first reviews related literature regarding the educational effectiveness of serious games. It then discusses how to assess the learning impact of serious games and methods for competence and skill assessment. Finally, it suggests two major directions for future research: characterization of the players activity and better integration of assessment in games.

User Assessment in Serious Games and Technology-Enhanced Learning

1 Department of Naval, Electric, Electronic and Telecommunications Engineering, University of Genoa, Via all’Opera Pia 11/a, 16145 Genoa, Italy 2 Faculty of Business and Information Technology, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Canada L1H 7K4 3Department of Mechanical and Aerospace Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA 4 Faculty of Computer Science, Universidad Complutense de Madrid, Ciudad Universitaria Universidad Complutense de Madrid, 28040 Madrid, Spain

Robotic Self-replication in Structured Environments: Physical Demonstrations and Complexity Measures

In this paper we define a complexity ratio that measures the degree to which a robot is self-replicating based on the number and complexity of subsystems that it can assemble to form a functional replica. We also quantify how structured the environment must be in order for a robot to function. This calculation uses Sandersons concept of parts entropy. Together, the complexity measure of the robot and environmental entropy provide quantitative benchmarks to assess the state of the art in the subfield of self-replicating robotic systems, and provide goals for the design of future systems. We demonstrate these principles with three prototype systems that show different degrees of robotic self-replication. The first robot is controlled by a microprocessor and consists of five subsystems. The second has no microprocessor and is implemented as a finite-state machine consisting of discrete logic chips that are distributed over five subsystems. The third design consists of six subsystems and is able to handle greater environmental entropy. These systems demonstrate the desired progression towards self-replicating robots consisting of greater numbers of subsystems, each of lower complexity, and which are able to function in environments with increasing levels of disorder.

OrigamiBot-I: A Thread-Actuated Origami Robot for Manipulation and Locomotion

This paper presents OrigamiBot-I, a thread-actuated origami robot, to demonstrate a physical application of an origami design for robotic manipulation and locomotion. The selected design can generate twisting and bending motions by pulling, pushing, or torsional force applied to the origami structure. Thread-based actuation also enables various shapes and motions by using different numbers of threads and routing them through different paths. The kinematics for each twisting and bending motions based on estimated parameters is derived. To evaluate potential use of origami for real-world applications and identify structural weaknesses, preliminary stiffness and durability testing was conducted. For physical demonstrations of robotic manipulation and locomotion, OrigamiBot-I was equipped with four independently-routed threads, where each thread is controlled by a geared DC motor. The robot successfully demonstrated its simple manipulation and locomotion capabilities.

TaG-Games: Tangible geometric games for assessing cognitive problem-solving skills and fine motor proficiency

This paper presents Tangible Geometric Games (TaG-Games) as a novel play-based assessment tool for measuring cognitive problem-solving skills and fine motor proficiency. TaG-Games are based on sensor-integrated geometric blocks (SIG-Blocks) and an interactive graphical user interface providing a means for real-time and remote monitoring of a player through wireless communication between the blocks and a host computer. The data made available by employing TaG-Games includes: 1) accelerations, 2) time at each stage of assembly completion, 3) total completion time for each quiz, and 4) correctness of each assembly step. In addition, the user interface displays the real-time assembly configuration of the blocks. As a computational method for analyzing complexity associated with geometric play, a quantitative measure of play complexity is defined based on an information-theoretic approach. The validity of the sensors integrated in each SIG-Block (an accelerometer and optical sensors) is evaluated for measuring tilt angles and detecting assemblies between the blocks.

A New Perspective on O(n) Mass-Matrix Inversion for Serial Revolute Manipulators

This paper describes a new algorithm for the efficient mass-matrix inversion of serial manipulators. Whereas several well-known O(n) algorithms already exist, our presentation is an alternative and completely different formulation that builds on Fixman’s theorem from the polymer physics literature. The main contributions here are therefore adding a new perspective to the manipulator dynamics literature and providing an alternative to existing algorithms. The essence of this theory is to consider explicitly the band-diagonal structure of the inverted mass matrix of a manipulator with no constraints on link length, offsets or twist angles, and then build in constraints by appropriate partitioning of the inverse of the unconstrained mass matrix. We present the theory of the partitioned mass matrix and inverse of the mass matrix for serial revolute manipulators. The planar N-link manipulator with revolute joints is used to illustrate the procedure. Numerical results verify the O(n) complexity of the algorithm. Exposure of the robotics community to this approach may lead to new ways of thinking about manipulator dynamics and control.

Robotic self-replication

The paper introduce a descriptive framework for robotic replicating systems that extends von Neumanns classical model of self-reproducing automata. A new physical prototype is developed to examine principles and uncover hardware limitations of kinematic reproduction at a low-complexity level in man-made physical systems. The initial functional robot assembles six subsystems located in a partially structured environment to form an exact functional replica of itself. Self-replication of the sort demonstrated here can be achieved by designing a robotic system composed of multiple simple parts/subsystems rather than a relatively few complex robotic modules. Therefore, this prototype hints at the feasibility of the concept of fully autonomous man-made machines that can construct functional copies of themselves from many very basic components. As a simple measure of system complexity, the number of active elements in each subsystem and interconnections between subsystems are counted. In addition, we present a measure of the degree of replication that includes the complexity distribution and the relative complexity of the total system to individual parts.

Adaptive Face Recognition for Low-Cost, Embedded Human-Robot Interaction

This paper presents an accelerated AdaBoost face detection algorithm and an incremental PCA-based face recognition algorithm for human robot interactive applications. The accelerated AdaBoost algorithm utilizes an image resizing technique and a skin color filter for detecting face regions. To track a detected face precisely and efficiently while also recognizing the face, a hybrid face tracking approach is applied based on an adaptive skin color mode and an estimated potential face area. In addition, a novel adaptive face recognition method is implemented by automatically upgrading the set of sample faces of a known person and collecting new samples of an unknown person with incrementally enhanced recognition performance. These algorithms are well suited for embedded systems, such as socially interactive robots, because of their cost and time efficiency and little pre-training required for reliable performance.

O(n) mass matrix inversion for serial manipulators and polypeptide chains using Lie derivatives

Over the past several decades, a number of O(n) methods for forward and inverse dynamics computations have been developed in the multibody dynamics and robotics literature. A method was developed by Fixman in 1974 for O(n) computation of the mass-matrix determinant for a serial polymer chain consisting of point masses. In other of our recent papers, we extended this method in order to compute the inverse of the mass matrix for serial chains consisting of point masses. In the present paper, we extend these ideas further and address the case of serial chains composed of rigid-bodies. This requires the use of relatively deep mathematics associated with the rotation group, SO(3), and the special Euclidean group, SE(3), and specifically, it requires that one differentiates real-valued functions of Lie-group-valued argument.

Design and analysis of an origami-based three-finger manipulator

This paper describes a new robotic manipulator with three fingers based on an origami twisted tower design. The design specifications, kinematic description, and results from the stiffness and durability tests for the selected origami design are presented. The robotic arm is made of a 10-layer twisted tower, actuated by four cables with pulleys driven by servo motors. Each finger is made of a smaller 11-layer tower and uses a single cable directly attached to a servo motor. The current hardware setup supports vision-based autonomous control and internet-based remote control in real time. For preliminary evaluation of the robots object manipulation capabilities, arbitrary objects with varying weights, sizes, and shapes (i.e., a shuttlecock, an egg shell, a paper cub, and a cubic block) were selected and the rate of successful grasping and lifting for each object was measured. In addition, an experiment comparing a rigid gripper and the new origami-based manipulator revealed that the origami structure in the fingers absorbs the excessive force applied to the object through force distribution and structural deformation, demonstrating its potential applications for effective manipulation of fragile objects.