Tzone I. Wang

A blog-based dynamic learning map

Problem-based learning is a goal directed and constructive process for learners. When meeting problems, learners usually force themselves to form work groups in order to find a solution. Currently, blogs are becoming more popular and in fact has formed a community wherein people can share their learning experiences with others. Many pedagogical applications have adopted what are posted in the community for supplementary learning. Integrating blogs in an intelligent tutoring system means that learners can better regulate and enhance their own learning. In this study, a novel learning device, a blog-based dynamic learning map, which employs both information retrieval and automated scheduling techniques, is designed to provide useful blog articles to help learning. The relevant articles in blogs are used to promote learner engagement in their interactions with the learning map and hence achieve their goals more easily. An experimental course has been implemented and the results show that learners make use of the blog-based learning aid in a very positive way and can eventually cross the specified threshold in a test. The proposed approach can encapsulate the dynamic learning principles in cohesive and supportive ways. Thus it can lead learners to gain useful supplementary materials, shorten the learning time and offering expanded alternative viewpoints to use in the solution of assigned problems. Our results show that both the learners and lectures are very positive to the design of our blog-based dynamic learning map.

Java learning object ontology

This paper presents an ontology, the Java learning object ontology - JLOO, for organizing learning objects of Java courses in an adaptive e-learning environment. The classification is based on the computing curricula CC2001 of the ACM and IEEE/CS. Using the curriculum as a guideline, the ontology defines the atomic knowledge units (i.e. learning objects) for an introductory course of Java programming. The most significant contributions of JLOO are: 1) defining the atomic knowledge units of introductory courses of Java language, and the relationships among them, 2) making the knowledge units of JLOO sharable and reusable, 3) allowing different learning strategies of a e-learning environment to choose dynamically, using JLOO as a guideline, different learning paths, and 4) making the realization of adaptive learning easy.

A mining-based approach on discovering courses pattern for constructing suitable learning path

In recent years, browser has become one of the most popular tools for searching information on the Internet. Although a person can conveniently find and download specific learning materials to gain fragmented knowledge, most of the materials are imperfect and have no particular order in the content. Therefore, most of the self-directed learners spend most of time in surveying and choosing the right learning materials collected from the Internet. This paper develops a web-based learning support system that harnesses two approaches, the learning path constructing approach and the learning object recommending approach. With collected documents and a learning subject from a learner, the system first discovers some candidate courses by using a data mining approach based on the Apriori algorithm. Next, the leaning path constructing approach, based on the Formal Concept Analysis, builds a Concept Lattice, using keywords extracted from some selected documents, to form a relationship hierarchy of all the concepts represented by the keywords. It then uses FCA to further compute mutual relationships among documents to decide a suitable learning path. For a chosen learning path, the support system uses both the preference-based and the correlation-based algorithms for recommending the most suitable learning objects or documents for each unit of the courses in order to facilitate more efficient learning for the learner. This e-learning support system can be embedded in any information retrieval system for surfers to do more efficient learning on the Internet.

Efficient parity placement schemes for tolerating triple disk failures in RAID architectures

This paper proposes two improved triple parity placement schemes, the HDD1 (horizontal and dual diagonal) and HDD2 schemes, to enhance the reliability of a RAID system. Both schemes can tolerate up to three disk failures by using three types of parity information (horizontal, diagonal, and anti-diagonal parities) in RAID disk block partitions. The HDD1 scheme can reduce the occurrences of bottlenecks because its horizontal and anti-diagonal parities are uniformly distributed over a disk array, while diagonal parities are placed in a dedicated disk. The HDD2 scheme uses one more disk than HDD1 to store the horizontal parities and an additional diagonal parity, while the anti-diagonal and the diagonal parities are placed in the same way as in the HDD1 scheme, only with a minor difference. The encoding and decoding algorithms of both schemes are simple and effective. Many of the steps of the encoding and decoding algorithms can be executed in parallel. Both schemes enable a RAID to recover rapidly from up to three disk failures, with a single algorithm applied straightforwardly.

Construction and analysis of educational assessments using knowledge maps with weight appraisal of concepts

The rapid advance of information and communication technologies (ICT) has important impacts on teaching and learning, as well as on the educational assessment. Teachers may create assessments utilizing some developed assessment software or test authoring tools. However, problems could occur, such as neglecting key concepts in the curriculum or having disproportionate course topics distribution, when teachers create assessments or test items. This study proposes a novel approach, which uses knowledge map with appraisal of concept weights and other ICTs, and implements an assessment system KMAAS to help primary school teachers in Taiwan, or elsewhere, create educational assessments properly. When compiling an assessment, KMAAS ensures that teachers can include all important course concepts intended for assessing and maintain correct balance between course concepts among test items. It does so first by analyzing course material of the assessment range and displaying a concept-weight-annotated knowledge map which concretize and visualize the importance of and the relationships among concepts in the range. It then analyzes the test sheet which is being complied and displays another similar real-time updated knowledge map containing balance between course concepts among the test items. Teachers may cross-refer to these maps to help them adjust concept balances and even select appropriate test items from test banks. The system has being evaluated in both the accuracy of learning concepts extraction and the degree of user satisfaction, as measured by questionnaires given to the teachers who tested the system. The promising results confirm the feasibility of this system in helping teachers compile their educational assessments easily and precisely. Other results of the formative evaluations on techniques have being used to improve the system in order to make it more effective and efficient. The methodology and technologies KMAAS employed are all well developed and are domain independent, which makes it highly flexible to transfer to other course subject domain too.

Mobile Agents for Distributed Transactions of a Distributed Heterogeneous Database System

A Distributed Heterogeneous Database System (DHDBS) is constituted of different kinds of autonomous databases connected to the network. A distributed transaction in such a system involves many sub-transactions and data movements among database sites. For the time being, most of the commercial database products implement their distributed transactions using the traditional client/server model that is suffering from enormous data movements. This paper proposes a new distributed transaction model which uses mobile agent technology to reduce data traffics in distributed transactions. The idea is backed by the well-known characteristics, such as mobility, autonomy, and concurrency, of mobile agents in supporting distributed computations. The aim is to boost the performance of distributed transactions of a heterogeneous database system in a loosely coupled environment (such as the Internet). An procedure is designed for distributed query decomposition. Some principles are observed for the path planning of a mobile agent roaming the network to carry out various sub-transactions.

Resilient Cluster-Organizing Key Management and Secure Routing Protocol for Mobile Ad Hoc Networks

Unlike traditional networks, the characteristics of mobile wireless devices that can dynamically form a network without any infrastructure and wired line mean that mobile ad hoc networks frequently display partition owing to node mobility or link failures. Consequently, an ad hoc network is difficult to provide on-line access to trusted authorities or centralized servers. Despite the existence of well-known security mechanisms, the absence of a stationary central authorization facility in an open and distributed communication environment is a major challenge. Consequently, applying traditional Public Key Infrastructure (PKI) security architecture to mobile ad hoc networks will create secure blind sides. Based on this perspective, this study proposes a novel scalable and robust cluster-organized key management scheme. Distribution of trust to an aggregation of cluster heads using a threshold scheme faculty provides mobile ad hoc networks with robust key management. Furthermore, the proposed approach provides Certificate Authority (CA) with a fault tolerance mechanism to prevent a single point of compromise or failure, and saves CA large repositories from maintaining member certificates, making the proposed approach more suitable for numerous mobile devices. Additionally, this study proposes a Cluster Secure Based Routing Protocol (CSBRP) to integrate into the key management to enhance non-repudiation of routing information and routing performances. Finally, this study introduces a mathematical model to demonstrate that the proposed cluster-based communication outperforms the node-based approach.

The Development of SCORM-Conformant Learning Content Based on the Learning Cycle Using Participatory Design.

This study incorporates the 5E learning cycle strategy to design and develop Sharable Content Object Reference Model-conformant materials for elementary science education. The 5E learning cycle that supports the constructivist approach has been widely applied in science education. The strategy consists of five phases: engagement, exploration, explanation, elaboration and evaluation. It has potential value for creating effective science e-learning materials. This study implemented the participatory design (PD) method to investigate the possibility of applying the 5E model to science e-learning materials. PD is an approach that understands knowledge by doing and focuses on collaborating with the intended users rather than designing ‘for’ them. In this study, researchers, designers and elementary science teachers cooperated at all stages of the design process (including explanation, analysis and decision making). The issues to be dealt with in this study included instructional designs based on the 5E model, techniques or specifications of e-learning, learning objects, metadata and procedures. The results of this study provided concrete recommendations for how to incorporate the 5E learning cycle and how to develop effective e-learning materials for elementary science instruction.

Inter-cluster routing authentication for ad hoc networks by a hierarchical key scheme

Dissimilar to traditional networks, the features of mobile wireless devices that can actively form a network without any infrastructure mean that mobile ad hoc networks frequently display partition due to node mobility or link failures. These indicate that an ad hoc network is difficult to provide on-line access to a trusted authority server. Therefore, applying traditional Public Key Infrastructure (PKI) security framework to mobile ad hoc networks will cause insecurities. This study proposes a scalable and elastic key management scheme integrated into Cluster Based Secure Routing Protocol (CBSRP) to enhance security and non-repudiation of routing authentication, and introduces an ID-Based internal routing authentication scheme to enhance the routing performance in an internal cluster. Additionally, a method of performing routing authentication between internal and external clusters, as well as inter-cluster routing authentication, is developed. The proposed cluster-based key management scheme distributes trust to an aggregation of cluster heads using a threshold scheme faculty, provides Certificate Authority (CA) with a fault tolerance mechanism to prevent a single point of compromise or failure, and saves CA large repositories from maintaining member certificates, making ad hoc networks robust to malicious behaviors and suitable for numerous mobile devices.

Integrating a semantic-based retrieval agent into case-based reasoning systems

This paper integrates techniques of natural language processing into a case retrieval agent.The use of semantic and syntactic information defines the meanings more accurately.Integrating semantic-based retrieval agent into the CBR system improves performance at initial state.The proposed CBR system with collaborative filtering constantly improves recommendation quality.The proposed CBR model outperforms the compared systems in the case study of an online bookstore. Natural language search engines should be developed to provide a friendly environment for business-to-consumer e-commerce that reduce the fatigue customers experience and help them decide what to buy. To support product information retrieval and reuse, this paper presents a novel framework for a case-based reasoning system that includes a collaborative filtering mechanism and a semantic-based case retrieval agent. Furthermore, the case retrieval agent integrates short-text semantic similarity (STSS) and recognizing textual entailment (RTE). The proposed approach was evaluated using competitive methods in the performance of STSS and RTE, and according to the results, the proposed approach outperforms most previously described approaches. Finally, the effectiveness of the proposed approach was investigated using a case study of an online bookstore, and according to the results of case study, the proposed approach outperforms a compared system using string similarity and an existing e-commerce system, Amazon.