• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.542-542
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• 2002

Geometric correction is a critical step to remove geometric distortions in satellite images. For correct geometric correction, Ground Control Points (GCPs) have to be chosen carefully to guarantee the quality of corrected satellite images. In this paper, we present an automatic approach for geometric correction by constructing GCP Chip database (GCP DB) that is a collection of pieces of images with geometric information. The GCP DB is constructed by exploiting Landsat's nadir-viewing property and the constructed GCP DB is combined with a simple block matching algorithm for efficient GCP matching. This approach reduces time and energy for tedious manual geometric correction and promotes usage of Landsat images.

• Journal of Information Processing Systems
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• 제4권2호
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• pp.41-52
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• 2008

In this paper, we discuss a novel reservation-based, asynchronous MAC protocol called 'Multi-rate Multi-hop MAC Protocol' (MMMP) for multi-hop ad hoc networks that provides QoS guarantees for multimedia traffic. MMMP achieves this by providing service differentiation for multirate real-time traffic (both constant and variable bit rate traffic) and guaranteeing a bounded end-to-end delay for the same while still catering to the throughput requirements of non real time traffic. In addition, it administers bandwidth preservation via a feature called 'Smart Drop' and implements efficient bandwidth usage through a mechanism called 'Release Bandwidth'. Simulation results on the QualNet simulator indicate that MMMP outperforms IEEE 802.11 on all performance metrics and can efficiently handle a large range of traffic intensity. It also outperforms other similar state-of-the-art MAC protocols.

• Journal of Information Processing Systems
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• 제6권2호
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• pp.209-218
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• 2010

Classical warranty plans require crisp data obtained from strictly controlled reliability tests. However, in a real situation these requirements might not be fulfilled. In an extreme case, the warranty claims data come from users whose reports are expressed in a vague way. Furthermore, there are special situations where several characteristics are used together as criteria for judging the warranty eligibility of a failed product. This paper suggests a fast reasoning model based on fuzzy logic to handle multi-attribute and vague warranty data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권1호
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• pp.238-256
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• 2016

Modern web services have been broadly deployed on the Internet. Most of these services use multi-tier architecture for flexible scaling and software reusability. However, managing the performance of multi-tier web services under dynamic and unpredictable workload, and different resource demands in each tier is a critical problem for a service provider. When offering quality of service assurance with least resource usage costs, web service providers should adopt self-adaptive resource provisioning in each tier. Recently, a number of rule- and model-based approaches have been designed for dynamic resource management in virtualized data centers. This survey investigates the challenges of resource provisioning and provides a competing assessment on the existing approaches. After the evaluation of their benefits and drawbacks, the new research direction to improve the efficiency of resource management and recommendations are introduced.

• 한국멀티미디어학회논문지
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• 제9권12호
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• pp.1617-1627
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• 2006

The concept of middleware for digital TV receivers is not new one. Using middleware for digital TV development has a number of advantages. It makes it easier for manufacturers to hide differences in the underlying hardware. It also offers a standard platform for application developers. Digital TV middleware enables set-top boxes(STBs) to run video, audio, and applications. The main concern of digital TV middleware is now to reduce its memory usage because most STBs in the market are small footprint. In this paper, we propose several ideas about how to reduce the required memory size on the runtime area of DTV middleware using a new native process technology. Our proposed system has two components; the Efficient Native Process Module, and Enhanced Native Interface APIs for concurrent native modules. With our approach, the required memory reduced from 50% up to 75% compared with the traditional approach. It can be suitable for low end STBs of very low hardware limitation.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2012년도 춘계학술발표대회논문집
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• pp.270-271
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• 2012

일반적인 네트워크 디지털 사이니지의 경우 모든 콘텐츠를 WAN상에 있는 대용량 스토리지에 보관을 하고 있으며, 필요한 멀티미디어 콘텐츠가 있을 경우 제한적인 로컬디스크에 다운로드 한 후에 재생 작업을 수행한다. 필요한 멀티미디어 콘텐츠의 신속한 확보를 위해 기존의 로컬디스크와 WAN 스토리지 사이에 콘텐츠 캐싱 기법을 포함하는 iSCSI 스토리지 계층이 추가된 하이브리드 스토리지 구조를 제안한다.

• Journal of Communications and Networks
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• 제7권4호
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• pp.478-488
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• 2005

To conserve the usage of energy, indexing techniques have been developed in a wireless mobile environment. However, the use of interleaved index segments in a broadcast cycle increases the average access latency for the clients. In this paper, we present the broadcast-based location dependent data delivery scheme (BBS) for dynamic range queries. In the BBS, broadcasted data objects are sorted sequentially based on their locations, and the server broadcasts the location dependent data along with an index segment. Then, we present a data prefetching and caching scheme, designed to reduce the query response time. The performance of this scheme is investigated in relation to various environmental variables, such as the distributions of the data objects, the average speed of the clients, and the size of the service area.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.946-950
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• 2003

In this paper, a computer-vision based pipe shape inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle. by which pipes with wrong end-shape can be classified removed.

• JSTS:Journal of Semiconductor Technology and Science
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• 제3권4호
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• pp.199-204
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• 2003

This paper proposes reconfigurable hardware structures for spreading and scrambling of multi-mode CDMA systems. The proposed reconfigurable structures supporting IS-95, cdma2000 and WCDMA, include a pseudo noise code generator, a channelization code generator and a control circuit for signal flow control. The proposed reconfigurable structures provide an efficient hardware usage for multi-mode CDMA systems. The synthesis results show the area reduction about 24.7% compared with the original code generators. The proposed structures can provide efficient reconfigurability and high speed operations for future SDR systems.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.717-719
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• 2013

건물 에너지 관리 시스템(BEMS)의 적용을 통해 실내 환경을 쾌적하게 유지함과 동시에 설비 시스템의 에너지 성능 극대화 및 수명연장의 효과를 기대할 수 있다. 국내에서도 컴퓨터의 범용화와 통신 기술의 발달, 그리고 건물의 대형화와 복잡화에 따라 건물 자동화와 통합관리 시스템의 중요성이 커지게 되었다. 본 논문에서는 이러한 건물 에너지 관리 시스템의 체계적인 설계에 관해 설명한다.