• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.1012-1019
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• 2014

The emerging smart utility networks (SUN) provide two-way communications between smart meters and smart appliances for purpose of low power usage, low cost, and high reliability. This paper deals with a bandwidth-efficient communication method based on the hidden pilot-aided scheme using a precoder in downlink SUN suitable for high-rate multimedia applications. With the aid of the design of a precoder and a superimposed hidden pilot, it is possible to estimate the channel without loss of bandwidth. In the channel estimation procedure, the inevitable data interference, which degrades the performance of channel estimation, can be reduced by the precoder design with an iterative scheme. Computer simulations show that the proposed scheme outperforms the conventional method in terms of achievable data rate, especially when a large number of subcarriers are employed.

• ETRI Journal
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• v.35 no.1
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• pp.142-145
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• 2013

Network virtualization opens the door to novel infrastructure services offering connectivity and node manageability. In this letter, we focus on the cost-efficient embedding of on-demand virtual optical network requests for interconnecting geographically distributed data centers. We present a mixed integer linear programming formulation that introduces flexibility in the virtual-physical node mapping to optimize the usage of the underlying physical resources. Illustrative results show that flexibility in the node mapping can reduce the number of add-drop ports required to serve the offered demands by 40%.

• Journal of Institute of Convergence Technology
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• v.10 no.1
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• pp.7-12
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• 2020

We describe a efficient surface reconstruction method that reconstructs a 3D manifold polygonal mesh approximately passing through a set of 3D oriented points. Our algorithm includes 3D convex hull, octree data structure, signed distance function (SDF), and marching cubes. The 3D convex hull provides us with a fast computation of SDF, octree structure allows us to compute a minimal distance for SDF, and marching cubes lead to iso-surface generation with SDF. Our approach gives us flexibility in the choice of the resolution of the reconstructed surface, and it also enables to use on low-level PCs with minimal peak memory usage. Experimenting with publicly available scan data shows that we can reconstruct a polygonal mesh from point cloud of sizes varying from 10,000 ~ 1,000,000 in about 1~60 seconds.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.119-122
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• 2000

Recently, many complex DSP (Digital Signal Processing) algorithms have being realized on RISC CPU due to good compilation, low power consumption and large memory space. But, real-time implementation of multiple DSP algorithms on RISC requires the minimum and efficient memory usage and the lower occupancy of CPU. In this thesis, the original floating-point code of MPEG-1 audio decoder is converted to the fixed-point code and then optimized to the efficient assembly code in time-consuming function in accord with RISC feature. Finally, compared with floating-point and fixed-point, about 30 and 3 times speed enhancements are achieved respectively. And 3~4 times memory spaces are spared.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.521-524
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• 2003

An effective purification method was developed for producing Homoharringtonine (HHT), to guarantee high purity and yield from Cephalotaxus koreana. This process was a simple and efficient procedure, for the isolation and purification of HHT form the biomass of Cephalotaxus koreana, consisting of extract, adsorbent treatment, precipitation and followed by a chromatography. The extraction, adsorbent treatment and precipitation in pre-purification process allows for rapid and efficient separation of HHT from many compound and dramatically increases the yield and purity of crude HHT for HPLC purification steps compared to alternative processes. This purification processes serves to minimize solvent usage, size, and complexity of the operations for HHT purification.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.1-8
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• 2009

There are several ways to solve parking problem in the downtown. One of them is to manage parking efficiently, that is, to raise use-efficiency of parking place and to help in the block efficiently, it can prevent disproportion that some parking space is over capacity and the other parking one is under. It causes not only the disproportion of economic efficiency but also the congestion of local road. The precondition to manage parking efficiently is to analyse the parking characteristics. In this paper we build up total D/B by collecting every information about parking space. We developed the Parking Management System by using RFID and Sensor. The efficient Parking Management System is for convenience of drivers and efficient usage of parking space. And this system is also the basic study to be developed as the total Parking Management System by upgrading every information.

• Journal of Korea Multimedia Society
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• v.4 no.1
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• pp.29-36
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• 2001

This paper proposes an efficient image description method for image retrieval using circular scanning pattern. Therefore, we place the origin of the circular scanning pattern on center point of an image and describe spatial color features of the image using the pattern. The features are Circular Dominant Color, Circular Color Texture, and Circular Color Variation Plot. By the method we can describe color and spatial information of the image at a time, efficiently. Therefore, we can reduce the computational expense and memory usage needed to index the image more than the conventional one does.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.2
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• pp.311-322
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• 1998

Modular BOMs are typically used in TWO-Level Master Production Schedule. To solve the problems of Modular BOM generation and efficient DB construction, we proposed Value Clustering Method. Based upon Where-Used matrix of products and components, VCM is the method to find out module by generating product family group value, product value, and component value. We also proposed method to find out information about Modules, algorithms to find out Modules that show Alternative Usage Pattern, and method to find out Modules used in a given product. We also compared the DB creation method by Value Clustering Method and by conventional method. We compared the size of DB in both methods. We mathematically proved that the proposed method is doing better as the size and complexity of product family gets larger and more complicated.

• Journal of Korea Multimedia Society
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• v.9 no.12
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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.

• Journal of Industrial Technology
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• v.5
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• pp.37-46
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• 1985

Recently-used structural reliability models are studied, and the usage and characteristics of each method are discussed. Although the First-Order Second Moment method may be efficient in structural reliability analysis, it has limitations which the limit state equation is linear and all the variables are normal. In that point, the Advanced Second-Moment(ASM) method have many good results, but computation of iterative method are trublesome. The results of ASM method similar to Variance Reduction Techniques(VRT), which is one of the Monte Carlo simulation methods. As a results, it is concluded that ASM method and VRT method are most efficient one.