• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.247-258
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• 2004

Recently, there have been researches on storage and retrieval technique of moving objects, which are highly concerned by user in database application area such as video databases, spatio-temporal databases, and mobile databases. In this paper, we propose a new signature-based indexing scheme which supports similar sub-trajectory retrieval at well as good retrieval performance on moving objects trajectories. Our signature-based indexing scheme is classified into concatenated signature-based indexing scheme for similar sub-trajectory retrieval, entitled CISR scheme and superimposed signature-based indexing scheme for similar sub-trajectory retrieval, entitled SISR scheme according to generation method of trajectory signature based on trajectory data of moving object. Our indexing scheme can improve retrieval performance by reducing a large number of disk access on data file because it first scans all signatures and does filtering before accessing the data file. In addition, we can encourage retrieval efficiency by appling k-warping algorithm to measure the similarity between query trajectory and data trajectory. Final]y, we evaluate the performance on sequential scan method(SeqScan), CISR scheme, and SISR scheme in terms of data insertion time, retrieval time, and storage overhead. We show from our experimental results that both CISR scheme and SISR scheme are better than sequential scan in terms of retrieval performance and SISR scheme is especially superior to the CISR scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2B
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• pp.148-158
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• 2011

Stationary nodes and mobile nodes co-exist wireless sensor network(WSN) can provide variety of new services. The stationary sensor node acts not only the gathering the environmental sensing data but also a access point to bidirectional communication with numerous mobile sensor nodes(mobile node), and the mobile sensor nodes are installed inside mobile objects and identify the location in real-time and monitor the internal status of the object. However, only using the legacy WSN protocol, it is impossible to set up the stable network due to the several reasons caused by the free-mobility of the mobile nodes. In this paper, we suggest three methods to increase the hit-ratio of the asynchronous message delivery(AMD) among mobile nodes. We verified the performance of the suggested methods under the stationary-mobile co-existed WSN testbed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.121-124
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• 2007

This paper describes the development of a brickwork game with three-dimensional computer graphics as one of web-based game contents. Client user using web can access and run lava applet program with the independence of hardware system. It consists of graphic user interface module, initial space generation module, event handler module, player control module, and thread control module. It uses 3-D array data structure for the 3-D graphic objects that are located in three-dimensional space for high-speed object searching and sorting. It enhances to compare with predetermined construction in three-dimensional space. We can use the developed racing game to inform game users of information for an advertisement like tourism information, and can apply the proposed 3-D drawing technology to 3-D game graphic engine core.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.2
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• pp.177-185
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• 2010

Ray-object intersection is an important element in ray tracing that takes up a substantial amount of computing time. In general, such spatial data structure as kd-tree has been frequently used for static scenes to accelerate the intersection computation. Recently, a few variants of kd-tree traversal have been proposed suitable for the GPU that has a relatively restricted computing architecture compared to the CPU. In this article, we propose yet another two implementation techniques that can improve those previous ones. First, we present a cached stack method that is aimed to reduce the costly global memory access time needed when the stack is allocated to global memory. Secondly, we present a rope-with-short-stack method that eases the substantial memory requirement, often necessary for the previous rope method. In order to show the effectiveness of our techniques, we compare their performances with those of the previous GPU traversal methods. The experimental results will provide prospective GPU ray tracer developers with valuable information, helping them choose a proper kd-tree traversal method.

• Journal of the Korean Institute of Gas
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• v.2 no.3
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• pp.88-95
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• 1998

Vibration analysis of rotating machinery can give an indication of possible faults thus allowing maintenance before further damage occurs. Current predictive maintenance system installed in Pyung-tak has the ability to diagnose the mechanical problems within the LNG Pump when the vibration exceeds preset overall alarm levels. In this study, LNG pump auto-diagnosis system based upon Windows NT and DSP Board is developed. This system analysis velocity signal acquired from dual accelerometer input monitor system to diagnose pump condition. Many plots which display machine condition are shown and features of vibration are stored in every time. If the fault is found, the system diagnoses automatically using expert system and trend monitoring. Operator checks pump condition intuitively using personal computer monitor.

• Journal of Korea Multimedia Society
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• v.9 no.1
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• pp.101-108
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• 2006

Developing a network game that is serviced on the internet requires a lot of work, time and manpower. Therefore, it is important to design a game in such a way so that existing design codes could be used. The database for the multi-player network game is accessed from many clients. To manage the resource effectively, it is required to design the APIs to be minimized the database access and to be dealt with the related data efficiently. For this, it is needed to apply the object-oriented design for the related software modules. In the paper, we propose the design patterns of GoF to implement the APIs thatis needed to deal with the database resource. The database design through the analysis of some game's GUI has the advantage to create the optimized schema set more quickly, because it minimize the review step and the modification step of the database design generally. In addition, we apply to the design patterns of GoF for the APIs design of the server-side database. These reduce the times of the program call between the game server and the database server. These also make easily the maintenance for the already developed APIs, and it makes easily the addition of new APIs.

• The KIPS Transactions:PartD
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• v.13D no.7 s.110
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• pp.879-888
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• 2006

Recently many researchers have focused on management of Historical trajectories of moving objects in Euclidean spaces due to numerous sizes of accumulated data over time. However, the movement of moving objects in real applications generally has some constraints, for example vehicles on roads can only travel along connected road networks. In this paper, we propose an indexing method for trajectories of moving objects on road networks in order to process the network-based spatiotemporal range query. Our method contains the connect information of road networks to use the network distance for query processing, deals with trajectories which are represented by road segments in road networks, and manages them using multiple R-trees assigned per each road segment. Furthermore, it has a structure to be able to share R-tree among several road segments in large road networks. Consequently, we show that our method takes about 30% less in node accesses for the network-based spatiotemporal range query processing than other methods based on the Euclidean distance by experiments.

• Korean Journal of Social Welfare
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• v.69 no.3
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• pp.65-96
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• 2017

This study aims at introducing the subjective experiences of the users who have been involved in care management, and finding out the meaning and essence of services. Total 16 interviewees who have experienced case management participated in a focus interview. The analysis of raw data brought about total 408 meaning units. Then, through restructuring and summarizing, 122 units of central meaning were revealed. After classifying 23 topics were found. Then, after consistent phenomenological comparison among the 23 topics, 7 essential topics were discovered. Based on the results and discussion above, this Study would like to suggest : approach to integrated care management of family, the meaning of social worker as the partner of life, the object of care management is the change from isolated being to understand the each other.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.275-281
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• 2015

The recent health care is growing rapidly want to receive offers users a variety of medical services, can be exploited easily exposed to a third party information on the role of the patient's hospital staff (doctors, nurses, pharmacists, etc.) depending on the patient clearly may have to be classified. In this paper, in order to ensure safe use by third parties in the health care environment, classify the attributes of patient information and patient privacy protection technique using hierarchical multi-property rights proposed to classify information according to the role of patient hospital officials The. Hospital patients and to prevent the proposed method is represented by a mathematical model, the information (the data consumer, time, sensor, an object, duty, and the delegation circumstances, and so on) the privacy attribute of a patient from being exploited illegally patient information from a third party the prevention of the leakage of the privacy information of the patient in synchronization with the attribute information between the parties.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.32-37
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• 2008

To ensure access to rapidly growing video collection, video indexing is becoming more and more important. In this paper, video ontology system for retrieving a video data based on a scene unit is proposed. The proposed system creates a semantic scene as a basic unit of video retrieval, and limits a domain of retrieval through a subject of that scene. The content of semantic scene is defined using the relationship between object and event included in the key frame of shots. The semantic gap between the low level feature and the high level feature is solved through the scene ontology to ensure the semantic-based retrieval.