This paper presents a smartphone-based fall detection scheme that allows smarphones to be placed in various positions. The scheme makes no assumption of the placement of the smartphones because it is inconvenient and impractical to ask users to place their smartphones in some designated positions; therefore it does not require the users place their phones in certain fixed positions. It utilizes the built-in three-axis accelerometer in the smartphone and constantly calculates the changes of the three axes and the angels to detect fall events. Unlike other schemes that require the smartphone be placed in certain fixed positions, the proposed scheme can detect fall events when the smartphone is placed in various positions, including pockets and bags, with little misjudgment. The experiment shows the proposed scheme can achieve 91.5% in sensitivity and 97.5% in specificity.

RDF and OWL are used as the data model and schema, respectively, to build the distributed knowledge base of the Semantic Web. The components in RDF models, subjects, predicates, and objects, are identified universally on the web, which makes it suitable for distributed operations. In this paper, we employ the distributed hash table (DHT) technology on peer-to-peer network to develop distributed RDF store. To take into account of ontology in RDF, we extend the chord ring to be two-level ring, where the first level is based on the ontology schema and the next one is on the RDF itself. The extension retains the complexity of O(log N) in maintaining and lookup message in an N-node system. The simulation results show that adding an additional level reduces the path length of message lookup. We design three-layered system architecture for the ontology-based distributed RDF store. We are developing a prototype according to the design in this paper to show how the two-level ring works.

Recent trend in the development of mobile devices, wireless communications, sensor technologies, weblogs, and peer-to-peer communications have prompted a new design opportunity for enhancing social interactions. This paper introduces our preliminary experiences in designing a prototype utilizing the aforementioned technologies to share life experience. Users equipped with camera phones coupled with short-range communication technology, such as RFID, can capture life experience and share it as weblogs to other people. However, in reality, this is easier said than done. The success of weblogs relies on the active participation and willingness of people to contribute. To encourage active participations, a ranking system, AgreeRank, is specifically developed to get them motivated.

XML Topic maps enable multiple concurrent views of sets of information objects and can be used to different applications. For example thesaurus-like interfaces to corpora navigational tools for cross-references or citation systems information filtering or delivering depending on user profiles etc. However to enrich the information of a topic map or to connect with some document's URI is very labor-intensive and time-consuming. To solve this problem we propose an approach based on natural language processing techniques to identify and extract useful information in raw Chinese text. Unlike most traditional approaches to parsing sentences based on the integration of complex linguistic information and domain knowledge we work on the output of a part-of-speech tagger and use shallow parsing instead of complex parsing to identify the topics of sentences. The key elements of the centering model of local discourse coherence are employed to extract structures of discourse segments. We use the local discourse structure to solve the problem of zero anaphora in Chinese and then identify the topic which is the most salient element in a sentence. After we obtain all the topics of a document we may assign this document into a topic node of the topic map and add the information of the document into the topic element simultaneously.

In this paper, we present an evaluation of anaphors generated by a Chinese natural language generation system.In the evaluation work, the anaphors in five test texts generated by three test systems employing generation rules with different complexities ~vere compared with the ones in the same texts created by twelve native speakers of Chinese.We took the average number of anaphors matching between the machine and human texts as a measure of the quality of anaphors generated by the test systems.The results suggest that the one we have chosen and which has the most complex rule is better than the other two.There axe, however, real difficulties in establishing the significance of the results because of the degree of disagreement among the native speakers.