Hanil Kim

A Telematics Service System Based on the Linux Cluster

This paper designs and implements a taxi telematics service system, aiming at providing an efficient framework by means of a Linux cluster to host emerging telematics services that need intensive computing. Combined with global positioning system and radio communication technology, the taxi telematics service system traces the position of taxis, finds a time saving route between start and destination points, dispatches the nearest taxi to the service call point based on the latest traffic information, and finally decides an efficient route for multiple destinations. The performance measurement result demonstrates that the implemented system can process up to 200 map matches for every minute, keeping average response time for other requests below 1.5 seconds.

Path prediction of moving objects on road networks through analyzing past trajectories

This paper addresses a series of techniques for predicting a future path of an object moving on a road network. Most prior methods for future prediction mainly focus on the objects moving over Euclidean space. A variety of applications such as telematics, however, require us to handle the objects that move over road networks. In this paper, we propose a novel method for predicting a future path of an object in an efficient way by analyzing past trajectories whose changing pattern is similar to that of a current trajectory of a query object. For this purpose, we devise a new function for measuring a similarity between trajectories by considering the characteristics of road networks. By using this function, we search for candidate trajectories whose subtrajectories are similar to a given query trajectory by accessing past trajectories stored in moving object databases. Then, we predict a future path of a query object by analyzing the moving paths along with a current position to a destination of candidate trajectories. Also, we suggest a method that improves the accuracy of path prediction by grouping those moving paths whose differences are not significant.

Personalization method for tourist point of interest (POI) recommendation

Today, travelers are provided large amount information which includes Web sites and tourist magazines about introduction of tourist spot. However, it is not easy for users to process the information in a short time. Therefore travelers prefer to receive pertinent information easier and have that information presented in a clear and concise manner. This paper proposes a personalization method for tourist Point of Interest (POI) Recommendation.

A New Method for Ontology Merging based on Concept using WordNet

Ontologies have been realized as the key technology for shaping and exploiting information for the effective management of knowledge and for the evolution of the semantic Web and its applications. However, it seems that there are always more than one ontology even for the same domain. In such a setting where different conceptualizations of the same domain exist, information services must effectively answer queries, bridging the gaps between their formal ontologies and users own conceptualizations. Therefore, coordination (i.e. mapping, alignment, merging) of ontologies is a major challenge for bridging the gaps between agents with different conceptualizations. So we propose a new method for ontology merging using WordNet. In this paper, we introduce ontology merging based on the horizontal approach and vertical approach. These approaches have different characters. The horizontal approach is to analyze mapping between ontologies through integrated similar concept in the same level. The vertical approach is the method which create the rule from similarity measure between concepts in the different level (when it is impossible in horizontal approach)

Domain knowledge ontology building for semantic video event description

A novel method for video event analysis and description based on the domain knowledge ontology has been put forward in this paper. Semantic concepts in the context of the video event are described in one specific domain enriched with qualitative attributes of the semantic objects, multimedia processing approaches and domain independent factors: low level features (pixel color, motion vectors and spatio-temporal relationship). In this work, we consider one shot (episode) in the Billiard Game of video as the domain to explain how the high-level semantic mapped into low level features and the detection of the semantically important event.

An Approach to Verifying Security and Timing Properties in UML Models

In this paper, we present an approach to verify whether a UML design model satisfies its domain-specific security and time-related requirements in an integrated tool environment. This approach is based on a UML metamodel extension mechanism given as profiles. As a model verification tool, we chose the USE (UML-based Specification Environment) since additional functional and non-functional constraints in a UML model should be formally specified using the OCL (Object Constraint Language). In order to address both security and timing properties together in a model, we combine two profiles, UMLsec for security and MARTE (UML profile for Modeling and Analysis of Real-Time and Embedded systems) for time, into the UML metamodel. Then, this combined metamodel is converted to a form of USE specification so that it can be used for verifying models using USE. In this approach, however, this combined metamodel is considered as a large class model in USE because USE does not support profiles. Therefore, models to be verified are created as object models that are instances of the given class model, i.e. the extended metamodel in our case. Our approach is illustrated with a distributed, interoperable wireless communications-based railroad control system called the Positive Train Control (PTC) System.

A Comparison of Web Searching Strategies According to Cognitive Styles of Elementary Students

The popularization of the Internet brought about easy access to a huge amount of information, yet it is not easy for one to find information in need. Therefore information users should have appropriate information search competencies to gather, analyze, and utilize it efficiently. In general people have their unique information search strategies, and consequently the retrieved results also significantly vary from one to another. This paper describes an experimental study on web searching strategies of elementary students and analyzes the variation in their searching strategies by examining their individual personalities, specifically their cognitive styles.

An efficient bandwidth management scheme for a hard real-time fuzzy control system based on the wireless LAN

This paper proposes and analyzes bandwidth allocation and reclaiming schemes on wireless media to enhance the timeliness of the real-time messages and accordingly the correctness of fuzzy control decision. Bandwidth allocation scheme generates efficient round robin polling schedule represented as a capacity vector by directly considering the deferred beacon problem. The resource reclaiming scheme reassigns unused slot time to non-real-time traffic by extending the collision period without violating the hard real-time guarantee. The simulation results show that the proposed scheme can not only enhance the schedulability of wireless network by up to 18% but also give more bandwidth to the non-real-time traffic up to 5.3%, while the resource reclaiming scheme can maximally improve the achievable throughput by 11% for the given stream set.

A personalized mobile learning system using multi-agent

Due to the recent development of the wireless communication industry, the learning system using the mobile technology, which is not restricted by time and space, has been researched. However, a learning system based on the level of users and a personalized service in accordance with the individual characteristics has been insufficient. Therefore, this paper proposes a system to offer a personalized service by adding the multi-agent system to the mobile English words learning system.

Efficient image retrieval using conceptualization of annotated images

As the amount of visual information is rapidly increasing, users want to find the more semantic information easily. Most retrieval systems by lowlevel features(such as color, texture) could not satisfy users demand. To interpret semantic of image, many researchers use keywords as textual annotation. However, its the image retrieval without ranking by text matching which is the simplest way to retrieval according to keywords existence or nonexistence. In this paper, we propose conceptualization by similarity measure using relations among keywords for efficient image retrieval. We experiment annotated image retrieval by lowering the unrelated keywords weight value and raising important keywords one.