Shuichi Yukita

An E-Learning System Based on the Top Down Method and the Cellular Models

As the broadband connectivity to the Internet becomes common, Web based e-learning and distance learning have come to play the central roles for self-learning, where learners are given much flexibility in choosing place and time to study. However, the learners still have to spend a lot of time before reaching the learning goal. This discourages the learners from continuing their studies and diminishes their motivation. To overcome this problem and to let the learners keep focusing on their primary interests, we propose a top-down e-learning system called TDeLS. The TDeLS can offer learners the learning materials based on the top-down (i.e., goal-oriented) method, according to the learners’ demands and purposes. Moreover, the TDeLS can distribute them to the learners through the Internet, and manage the database for learning materials. In order to share learning materials among learners through the Web, these learning materials are wrapped in XML with a specially designed vocabulary for TDeLS. We employed the cellular models that ensure the consistency among design modules and support a top-down design methodology. In this paper, we present the TDeLS for hardware logic design courses based on the cellular models. The primary goal is to design complex logic circuits in VerilogHDL, which is an industrial-standard hardware description language. This paper also presents the basic XML vocabulary designed to describe hardware modules efficiently, and a brief introduction to the structure and functions of the proposed system that implements the TDeLS.

An Effective Agile Teaching Environment for Java Programming Courses

This paper proposes an effective agile teaching environment with a new educational testing framework for especially Java programming courses. The testing framework is developed on top of JUnit that runs on the Eclipse platform. The deployed testing programs detect errors in the students code, and then report points lost due to mistakes, and give suitable pieces of advice to correct or improve the code immediately. With automated testing the students can check the validity of their code by themselves. This means that the instructor can concentrate on mentoring the students who are most in need of support and advice. Our proposed method also ensures the evaluation of assignments to be fair and strict by applying various well-behaved input patterns based on standard software testing techniques while saving time. With our testing framework, students are continuously aware of their progress under a game-like environment, and thereby they keep concentrating on their given tasks

Depthmap-based obstacle avoidance on rough terrain

It is an important and difficult task for a mobile robot to detect the maneuverable area and to avoid obstacles. Numerous methods using ultra sonic or infrared sensors have been successfully proposed and adapted to various robots. These robots, however, cannot move around in unleveled areas because their sensors are incapable of measuring in a three-dimensional (3D) environment. Some obstacle avoidance methods using 3D sensors were proposed. It is a problem to move the robot around smoothly and continuously, considering that these methods require numerous processing steps and time to determine the obstacles and the avoidance path. In this paper, a new obstacle avoidance method using a depthmap is proposed that applies 3D sensor technology to autonomous exterior robot systems. Employing this method the robot is able to recognize the obstacle continuously and thus can be used on rough terrain. All processes in the algorithm handle images without the environmental model. In recent years, a sensing device used for laser modules or CCD cameras that can sense 3D space in real-time have been developed. Using such a sensor in conjunction with the proposed method, the test unit and autonomous vehicle were built to evaluate the methodology in an outdoor environment These units were able to detect the obstacle, avoid it, and Iocomote autonomously on rough terrain. As a result, this method has the advantage of robustness on rough terrain, and an autonomous mobile robot with this test unit is capable of navigation on an unleveled road.

Top-down eLearning tools for hardware logic design

New top-down eLearning tools for hardware logic design courses using the cellular methods are presented that enable students to keep focusing on their primary interests so that they can achieve complex logic circuits design successfully. In a modern logic design classroom, hardware description languages such as VerilogHDL are mostly used to describe circuits for FPGAs. The circuit in each module is described in VerilogHDL and the entire circuit is implemented by combination of designed modules. These HDL descriptions are wrapped in XML and enriched by a specially extended XML vocabulary, in order to share designed modules among learners on the Web. Although XML gives us a common and convenient Web framework, it becomes difficult to verify, validate, and maintain conformance among designed modules if the system becomes very large. To overcome this problem, we employed the cellular models that ensure the consistency among design modules and support a top-down design methodology. The proposed top-down eLearning tools can generate these circuit design data, distribute them to the learner, and manage the design database. The circuit design data wrapped in XML vocabulary are offered to the learner as a self-learning material of the courseware using the top-down (i.e. goal-oriented) method, according to the demand.

The educational uses of mathematical ontology and the searching tool

In Japan, a huge number of entrance examination questions and school textbook exercises are accumulated in databases at various educational institutions and companies in education industry. These databases are now becoming more and more indispensable educational resources for teachers, educational researchers, and learners. However, since these resources are stored in a wide variety of forms, we cannot search useful data at the semantic level. To tackle the problem, we constructed mathematical ontology and developed the problem searching tool based on this ontology in our previous work. We use standard ontology technologies which were developed for shared use and reuse of knowledge. The ontology captures one or more expertspsila conceptual representation of a domain expressed in terms of concepts and the relationships among the concepts. We analyzed that the features of this technology could be the answer to solve above mentioned problem. In this paper, we describe an overview of the mathematical ontology and the searching tool, focusing on newly added functions, and demonstrate effective utilization of this tool in the field of mathematics education.

Mathematical Ontology and a Software Tool for Semantic Retrieval of Exercise Problems

A huge number of entrance examination questions are accumulated in databases at various educational institutions and companies in education industry. These questions are valuable resources for teaching materials at schools. However, these resources are not accessible at the semantic level, that is, we can not retrieve right data by specifying concepts or teaching goals independent of the ways of presentation and terminology. Though such problems in various fields are successfully tackled by introducing ontology technologies, little is accomplished in the educational domain. In this paper, we introduce an example of ontology in the field of mathematics education and present a problem searching tool based on the ontology to prove the effectiveness of our semantic approach.

Development of topdown courseware and cellular models

Frameworks for applying the cellular models, proposed by the authors years ago, are investigated aiming to reduce the complexity of courseware design. Development of topdown courseware involves the task of arranging the contents which are logically hypertextualized so that learners can walk through the courses with utmost ease. In many cases, the produced courseware must face with varieties of learners who have different backgrounds, failing often to meet the demands of the majority of both teachers and learners. An ideal solution to this problem is to produce customized versions of the courseware, each of which is so arranged that each learner can maintain and increase ones primary interest and motivation. However, the time complexity involved in such a process is combinatorial, which can be reduced to an amenable task only when, at present, experienced teachers or courseware designers are involved. In general, developing courseware takes much human resources. Using the cellular models, we can save courseware projects from this difficulty. We propose here a courseware design method based on the cellular database technology that greatly reduces the complexity of designing processes in orders of magnitude, aiming to promote the development of courseware for topdown education.

Linear cellular automata on Cayley graphs

Linear cellular automata on Cayley graphs of some class of groups are studied. The injectivity and surjectivity of parallel maps are shown to be determined by their local maps. The main theorems are non-Euclidean extensions of Itô, Ôsato, and Nasu’s results on the injectivity and surjectivity of linear cellular automata [Linear Cellular Automata over Zm, Journal of Computer and System Sciences,27 (1983), pp. 125–140]. The proofs are based on Machì and Mignosi’s Garden of Eden theorem [Garden of Eden configurations for cellular automata on Cayley graphs of groups, SIAM Journal on Discrete Mathematics, 6 (1993), pp. 44–56] and properties of unique product groups. Examples of groups that allow the Itô-Ôsato-Nasu type theorem and of groups that do not are given.

S2Directory A Framework for Object-Directory Mapping with Dynamic Implementation Injection

Object models adopted in the object oriented software development reflect complex relations that exist between various entities in the real world. On the other hand, directory models adopted in directory service technologies map various relations into tree structures. Therefore, developing directory services by object oriented languages require writing lengthy procedures that bridge the gaps between object models and directory models. To overcome this drawback, in this paper, we propose a new technology named Object- Directory Mapping. We also present a Java based framework S2Directory to prove the effectiveness of the concept of Object-Directory Mapping. Implementation details are also given together with new dynamic implementation injection techniques.

Top-down learning navigator based on the cellular models

This paper discusses navigator tools for the top-down learning system. The top down education is a type of goal-oriented education. The present education is generally conducted bottom-up, from basics to applications, and hence learners have to spend a lot of time before reaching the goal to lose their interest. In the top-down education, since they start from their goals, they can keeps focused on their primary interest to shorten the learning time by well motivated study. The navigator tools to lead learners in the hierarchy are implemented based on the cell models and the cellular databases. The study programs are dynamically generated by the navigation tools that match the learners systematically. Another main feature of the navigator tools is its ability to dynamically adapt itself to the learners background and interests. This feature is made possible by the cellular model. The cell model is an information model advocated by one of the authors (TLK) [Kunii2002, Kunii2003]. It is based on the incrementally modular abstraction hierarchy. The prototype version of the navigator tools is implemented by the Python-based object-oriented ZOPE system and the ZOPE version of dynamic HTML.