• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.441-443
• /
• 2010

Techniques for processing continuous queries are required to developing the various types of application services in ubiquitous environment where the real-time data acquisition from a lot of sensors, analysis, and processing are required. In the previous works of the continuous queries, they have represented all of the continuous queries as the interval queries or region queries, and proposed some methods for processing theses queries. The types of continuous queries, however, are very various, and could be presented by combining the attribute conditions, spatial conditions, and temporal conditions. In this paper, I have classify the types of continuous queries, and have proposed the continuous query model which could be presented by combining those conditions. The contributions of this paper include that it proposes the query model representing the continuous queries and suggests future research directions.

• Healthcare Informatics Research
• /
• v.24 no.4
• /
• pp.387-393
• /
• 2018

Objectives: This paper describes an experience of implementing seamless service trials online and offline by adopting Internet of Things (IoT) technology based on near-field communication (NFC) tags and Bluetooth low-energy (BLE) beacons. The services were provided for both patients and health professionals. Methods: The pilot services were implemented to enhance healthcare service quality, improve patient safety, and provide an effective business process to health professionals in a tertiary hospital in Seoul, Korea. The services to enhance healthcare service quality include healing tours, cancer information/education, psychological assessments, indoor navigation, and exercise volume checking. The services to improve patient safety are monitoring of high-risk inpatients and delivery of real-time health information in emergency situations. In addition, the services to provide an effective business process to health professionals include surveys and web services for patient management. Results: Considering the sustainability of the pilot services, we decided to pause navigation and patient monitoring services until the interference problem could be completely resolved because beacon signal interference significantly influences the quality of services. On the other hand, we had to continue to provide new wearable beacons to high-risk patients because of hygiene issues, so the cost increased over time and was much higher than expected. Conclusions: To make the smart connected hospital services sustainable, technical feasibility (e.g., beacon signal interference), economic feasibility (e.g., continuous provision of new necklace beacons), and organizational commitment and support (e.g., renewal of new alternative medical devices and infrastructure) are required.

• Journal of Information Technology Services
• /
• v.13 no.3
• /
• pp.235-255
• /
• 2014

Social Network Service (SNS) with emergence of Web 2.0 have been developed rapidly. Unlike other games, social network game is based on the relationship with smart devices and studied for user-centered behavior as a potential factor derived from the Technical Acceptance Model (TAM). This research is conducted for finding out influencing factors on continuous intention for smart device users. Therefore, the independent variables consist of subjective norm, mobility, playfulness, self-efficacy, and ease of use. The intermediate variables also compose of flow, and user satisfaction and the dependent variables as continuous intention. The result of study shows the following: First, subjective norm, playfulness, self-efficacy and ease of use except mobility have the positive effect on user flow. Second, subjective norm, mobility, playfulness and ease of use except self-efficacy have significantly the positive effect on user satisfaction. Finally, user flow has significantly the positive effect on user satisfaction and continuance intention and a factor of user satisfaction have significantly the positive effect on continuance intention.

• Journal of the Korean Data and Information Science Society
• /
• v.19 no.2
• /
• pp.645-655
• /
• 2008

As wireless connectivity is integrated into many handheld devices, streaming multimedia content among mobile ad-hoc peers is becoming a popular application. In this paper, we propose a dynamic service replication algorithm for providing guaranteed continuous streaming services to all nodes in mobile ad-hoc networks (MANETs). First, a MANET is comprised of logical grid hierarchy, and a streaming service is replicated to a lower server region of the logical grid hierarchy by considering the link availability between a mobile node and the streaming server within a server region or the popularity of the streaming service. We evaluate analytically the performance of the proposed algorithm, and compared with that of existing Qin's algorithm. Evaluation results show that our algorithm can achieve better streaming performance than Qin's algorithm. Therefore, the proposed algorithm not only improves the sharing availability of replicated streaming services but also controls efficiently the number of streaming service replications.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.2
• /
• pp.162-169
• /
• 2009

The real-time traffic data is generated continuous and unbounded stream data type while intelligent transport system (ITS) needs to provide various and high quality services by combining with spatial information. Traditional database techniques in ITS has shortage for processing dynamic real-time stream data and static spatial data simultaneously. In this paper, we design and implement an advanced traffic monitoring system (ATMS) with the integration of existed data stream management system (DSMS) and spatial DBMS using IntraMap. Besides, the developed ATMS can deal with the stream data of DSMS, the trajectory data of relational DBMS, and the spatial data of SDBMS concurrently. The implemented ATMS supports historical and one time query, continuous query and combined query. Application programmer can develop various intelligent services such as moving trajectory tracking, k-nearest neighbor (KNN) query and dynamic intelligent navigation by using components of the ATMS.

• Knowledge Management Research
• /
• v.18 no.4
• /
• pp.237-260
• /
• 2017

Recently, with the proliferation of smart phones and mobile devices and the increase in the speed of mobile Internet, IT services are increasingly used in smart phones and mobile devices in a different way from the past. That is, a cloud service that downloads and uses data stored in the server in real time is expanding, and as a result, the security due to the continuous Internet connection of the user becomes a problem. In this study, we analyzed the relationship between factors affecting the continuous use of personal cloud service by using technology acceptance model. In addition to the technology acceptance model, confidentiality, privacy, accessibility, innovation, and self-efficacy were extracted from the existing research with emphasis on the characteristics of the cloud service and security factors. Moreover, the difference of intention to use among genders was verified through structural equation modeling with survey data from 262 personal cloud service users.

• Journal of KIISE:Databases
• /
• v.37 no.5
• /
• pp.250-257
• /
• 2010

As the variant of skyline query processing, reverse skyline Queries have been studied. However, the existing methods for processing reverse skyline Queries have the limitation of service domains and spend high costs to provide various location-based services. In this paper, we propose a new reverse skyline Query processing method that efficiently processes a query with the objects in metric spaces. In addition, the proposed method also processes continuous reverse skyline queries efficiently. In order to show the superiority of the proposed scheme, we compare it with the previous reverse skyline 벼ery processing scheme in various environments. As a result, the proposed method achieves better performance than the existing method.

• Journal of Distribution Science
• /
• v.17 no.12
• /
• pp.43-54
• /
• 2019

Purpose: Marine transportation companies must improve service quality to secure competitive advantage and continuous relationships with customers. This study explores the value and necessity of service quality in the industry by empirically identifying the factor that would have the largest effect on the improvement of service quality, also examining whether such improvement may actually influence continuous relationships. Research design, data and methodology: Based on an online survey with those in the Korean marine transportation industry, this study conducted statistical analyses using structural equation modeling. Based on relevant previous studies, the current study constructed a total of 55 survey questions. Finally, 281 questionnaires were collected, but 68 were excluded owing to invalid responses. Results: Information service attribute had the largest effect on service quality, whereas communication did not demonstrate a significant influence. In addition, distribution and information services exerted a positive effect on service satisfaction through service quality, and finally influenced relationship continuity. Conclusions: The results shows that marine logistics service quality strategies which were centered on time or local factors, should be considered in terms of the development of innovative services. In particular the improvement of information service systems and strategies in changed business environment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.11A
• /
• pp.1035-1046
• /
• 2005

This paper analyzes the channel assignment techniques and their performance in the On Board Processing (OBP) satellite communication system. It suggests the new Continuous Rate Assignment (CRA) and Dynamic Rare Assignment (DRA) for improving the efficiency of channel assignment at the OBP switch. Mathematical analysis and simulation are given to evaluate the system performance. Aggregate real-time and non-real-time services are considered as different classes. Higher priority is given to voice and video real-time services to avoid delay variation. Onboard scheduler uses CRA and DRA ways to arrange the capacity allocation dynamically. An improved algorithm is given to make the channel more efficient by doing some evaluation of the switching matrix.

• Electronics and Telecommunications Trends
• /
• v.33 no.1
• /
• pp.57-67
• /
• 2018

Modern users are intensifying their use of online services every day. In addition, hackers are attempting to execute advanced attacks to steal personal information protected using existing authentication technologies. However, existing authentication methods require an explicit authentication procedure for the user, and do not conduct identity verification in the middle of the authentication session. In this paper, we introduce an implicit continuous authentication technology to overcome the limitations of existing authentication technology. Implicit continuous authentication is a technique for continuously authenticating users without explicit intervention by utilizing their behavioral and environmental information. This can improve the level of security by verifying the user's identity during the authentication session without the burden of an explicit authentication procedure. In addition, we briefly introduce the definition, key features, applicable algorithms, and recent research trends for various authentication technologies that can be used as an implicit continuous authentication technology.