• Journal of Korean Society for Geospatial Information Science
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• v.24 no.4
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• pp.89-96
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• 2016

By reviewing preceding studies of big data and spatial big data, spatial big data was defined as one part of big data, which spatialize location information and systematize time series data. Spatial big data, as one part of big data, should not be separated with big data and application methods within the system is to be examined. Therefore in this study, services that spatial big data is required to provide were suggested. Spatial big data must be available of various spatial analysis and is in need of services that considers present and future spatial information. Not only should spatial big data be able to detect time series changes in location, but also analyze various type of big data using attribute information of spatial data. To successfully provide the requirements of spatial big data and link various type of big data with spatial big data, methods of forming sample points and extracting attribute information were proposed in this study. The increasing application of spatial information related to big data is expected to attribute to the development of spatial data industry and technological advancement.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.6
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• pp.1493-1504
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• 2010

The localization service which provides the location information of mobile user, is one of important service provided by sensor network. Many methods to obtain the location information of mobile user have been proposed. However, these methods were developed for only one mobile user so that it is hard to extend for multiple mobile users. If multiple mobile users start the localization process concurrently, there could be interference of beacon or ultrasound that each mobile user transmits. In the paper, we propose LME, the localization technique for multiple mobile nodes in mobile wireless sensor networks. In LME, collision of localization between sensor nodes is prevented by forcing the mobile node to get the permission of localization from anchor nodes. For this, we use CTS packet type for localization initiation by mobile node and RTS packet type for localization grant by anchor node. NTS packet type is uevento reject localization by anchor node for interference avoidance.nghe experimental result shows that the number of interference between nodes are increased in proportion to the number of mobile nodes and LME provides efficient localization.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.91-100
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• 2009

Given the increased interest in ubiquitous computing, wireless sensor network has been researched widely. The localization service which provides the location information of mobile user, is one of important service provided by sensor network. Many methods to obtain the location information of mobile user have been proposed. However, these methods were developed for only one mobile user so that it is hard to extend for multiple mobile users. If multiple mobile users start the localization process concurrently, there could be interference of beacon or ultrasound that each mobile user transmits. In the paper, we propose IAL, the localization technique with interference avoidance for multiple mobile nodes in mobile wireless sensor networks. In IAL, interference is prevented by forcing the mobile node to get the permission of localization from anchor nodes. For this, we define LIP packet type for localization initiation by mobile node and LGP packet type for localization grant by anchor node. LRP packet type is used to reject localization by anchor node for interference avoidance. The experimental result shows that the number of interference between nodes are increased in proportion to the number of mobile nodes and IAL provides efficient localization.

• Journal of Korean Society of Disaster and Security
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• v.6 no.3
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• pp.9-17
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• 2013

Geospatial information data came recently in use to build the location-based service in various fields. These data were shown via a 2-D map in the past but now can be viewed as a 3-D map due to the dramatic evolution of IT technology, thus improving efficiency and raising practicality to a greater extent by providing a more realistic visualization of the field. In addition, many previous GIS applications have been provided under desktop environment, limiting access from remote sites and reducing its approachability for less experienced users. The latest trend offers service with web-based environment, providing efficient sharing of data to all users, both unknown and specific internal users. Therefore, real-time information sensors that have been installed on steep slopes are to be integrated with 3-D geospatial information in this study. It is also to be developed with web-based environment to improve usage and access. There are three steps taken to establish this system: firstly, a 3-D GIS database and 3-D terrain with higher resolution aerial photos and DEM (Digital Elevation Model) have been built; secondly, a system architecture was proposed to integrate real-time sensor information data with 3D Web-based GIS; thirdly, the system has been constructed for Gangwon Province as a test bed to verify the applicability.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.517-520
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• 2008

Wireless sensor network supporting healthcare environment should provide customized service in accordance with context information such as continuous location change and status information for people or movable object. In addition, we should consider data transmission guarantees a person's bio information and privacy security provided through sensor network. In this paper analyzes LEACH protocol which guarantees the dynamic self-configuration, energy efficiency through configuration of inter-node hierarchical cluster between nodes and key distribution protocol used for security for data transmission between nodes. Based on this analysis result, we suggested self-configuration routing protocol supporting node mobility which is weakness of the existing LEACH protocol and data transmission method by applying key-pool pre-distribution method whose memory consumption is low, cluster unit public key method to sensor node.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.2
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• pp.215-225
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• 2006

This study was peformed to evaluate the served menu and investigate the management of food service in Korean Buddhist temples. Among the available temples in the nation, 34 temples were carefully selected considering practice type, location and the gender characteristics. A survey about meal preparation and management was conducted to the cooking staff in each the temple using questionnaire by interview between Jan 2004 and Aug 2004. The menus over A five consecutive days menu was were also collected for analysis to analyse. Civilian cooking staffs were preparing meals in 23(67.6%) of the temples and the proportion 18(52.9%) of the temples were planning their own the menus was 52.9%. Most kitchens in the temples were equipped with modernized kitchen appliances. The major food supply was the conventional market Even though the majority of the temples were using processed food, Korean fermented sauces as the most traditional temple food products were prepared by themselves. There were 114 menu patterns and the most frequently served meal pattern was ${\ulcorner}Rice+Soup+Kimchi+3{\sim}4\;side\;dishes{\lrcorner}$. Analyzing from the cultural characteristics point of view, the most frequently served dish type was 'Korean'(90%), while other types were 'modified Korean'(3.7%) and 'Western'(2.7%). The varieties of Various 438 different dishes provided were 438 provided and with Kimchies (19.8%), Seasoned vegetables(16.8%) and Rice(11.0%) being the highest were high in frequency when dishes were categorized into dish classes. Among the main dishes, the frequency of gruel(13.7%) was relatively high. These results suggest the need to conduct Based upon the results found, it was required to continue further research about preserving and inheriting the originality and uniqueness of the temple food.

• Journal of Korea Multimedia Society
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• v.7 no.2
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• pp.231-240
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• 2004

Location Based Service(LBS) system is widely used in Car Navigation Service(CNS), position tracing, tour guide, etc. Recently, the development of a mobile hardware enables us to run various application of software on small handset. Although CNS systems are widely used on personal computer, PDA and embedded machines, small display system of a mobile handset still constrains to make it difficult to developed route visualization and navigation system. In this paper, we propose a new route map visualization system on mobile handset environment for LBS system. We use modified line simplification algorithm that removes extraneous information and places more emphasis on the turning point. We also adopted level of detail route visualization technique for visualization of a detail map. This system improved turn-by-turn method and line drive system, which are widely adopted by current route visualization system.

• Journal of Internet Computing and Services
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• v.6 no.3
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• pp.55-70
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• 2005

In order to provide mobile hosts with multicast service in mobile communication environment, we proposed a multicast mechanism named HXcast++ which is an extended version of the existing Xcast++ with hierarchical architecture, We assured that mobile hosts could get multicast service through an optimal path regardless of their location by making DR(Designated Router) join a group on behalf of the mobile hosts, In this present research we introduced hierarchical architecture in order to reduce the maintenance cost resulting from frequent handoff. We also proposed a GMA (Group Management Agent) based group management mechanism which enables the mobile hosts to join the group without waiting for a new IGMP Membership Query. A fast handoff method with L2 Mobile Trigger was, in this work, employed in order to reduce the amount of the packet loss which occurs as a result of the handoff, We also managed to curtail the packet loss caused by the latency of the group join by using a buffering and forward mechanism.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.1
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• pp.19-27
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• 2007

Entering the 21st century, the demand on information service via mobile devices is skyrocketing along with the popularization of computers and mobile communication devices and the rapid development of wireless communication technology. In particular, as mobile device service such as LBS and Telematics becomes highlighted, the management of mobile devices is ever more drawing attention. However, since there is no fixed standard on geographical space data, many commercialized monitoring systems do not use common geographical space data but independent geographic information. Furthermore, as it is impossible to save location information of each mobile device by integrating such information after acquiring them, it is difficult to trace management. Therefore, in this paper, geographic data with DXF. DWG and SHP format, which are commonly used files, were created and visualized by GML format, OGC standard advice. And then, TMS(Trace Monitoring System of Mobile Device) that can trace and manage information after acquiring and saving space information that show the movement of users was implemented.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.2
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• pp.129-136
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• 2017

This study aims to assess the damage tolerance of the wing structure of aged aircraft with long-term service through the fatigue crack growth analysis and tests. For the fatigue-critical locations (FCL) W2 and W4 in the wing structure, the fatigue stress spectrum was derived based on a previous study. Thereafter, a crack propagation analysis for the FCLs was conducted using the commercial software $NASGRO^{TM}$. The algorithm for the fatigue stress spectrum was verified. Fatigue crack growth tests were then performed for two types of specimens: Type #1 was extracted from the wing structure of aged aircraft, and Type #2 was made of the same material as the wing structure. By comparing the experimental results of these specimens, we assessed the damage tolerance of the wing structure of aged aircraft with service time.