• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.5
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• pp.955-963
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• 2003

In this paper, in order to help one to write contents for education in such a way to increase effectiveness, we implement SMIL editor, which helps anyone to author contents for education and multimedia text in an easy way based on multimeda language SMIL. Thanks to its interface which utilizes WYSIWYGT, this editor allows teachers or other users who do not know SMIL to write contents for education and multimedia text in an easy way and to check in a real time how a partially completed document work and to revise when it is not satisfactory. It also allows one to write contents with explanations to help learning because usable multimedia objects can be inserted. This editor helps the user to reduce his inconvenience that he has in memorizing SMIL tags and to reduce his time and offers in writing the documents.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.2
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• pp.271-281
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• 2002

Currently, most web designers guarante high quality using bitmap graphics as fixed font size, but that has defects about file size and flexibility. Especially, to provide high quality of banner and advertise characters, after you should use a bitmap edit program, and then we should follow the method we add that program to HTML documents as bitmap data. In this study, as I show a couple of new tags in front of HTML documents, I show methods which can be presented diverse effects. When text information are stored, because we print out a screen with simple control points and outside information, it can be possible for us to express the same quality of Hangul characters like printed documents in a web browser. Regardless of the second class of platform, we can make it possible the character expression with exact character expressions and diverse effects.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.1008-1013
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• 2009

In this paper, we proposed the biological signal (body heat, pulse, breathe rate, and blood pressure) analysis system using wireless sensor. In order to analyze, we designed a back-propagation neural network system using expert group system. The proposed system is consist of hardware patt such as UStar-2400 ISP and Wireless sensor and software part such as Knowledge Base module, Inference Engine module and User Interface module which is inserted in Host PC. To improve the accuracy of the system, we implement a FEC (Forward Error Correction) block. For conducting simulation, we chose 100 data sets from Knowledge Base module to train the neural network. As a result, we obtained about 95% accuracy using 128 data sets from Knowledge Base module and acquired about 85% accuracy which experiments 13 students using wireless sensor.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.759-766
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• 2017

In this paper, we preserve the transparency of digital contents by compressing and storing the medical image for a certain period so as to be safe and robust against various attacks of medical images. The proposed algorithm generates an encrypted image authentication code that extracts the feature value of the original image and combines it with the user's information. in order to extract hidden data, the authentication code is first decrypts the encrypted medical image and extracts the hidden data using the spatial characteristics of image. The proposed algorithm guarantees integrity when comparing extracted authentication code and newly generated authentication code for image authentication after directly inserting it into content itself through watermarking. We have proved various security of attack of image data and proved that the certification rate is improved to 98.4%.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.11
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• pp.1269-1274
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• 2010

Wireless communication channels with the most severe multipath fading phenomenon that appears each time a different delay is caused by the frequency selective fading. At this time, ISI due to the performance degradation of wireless communication channels and data transfer speed gives the constraints. OFDM technique can remove ISI inserting longer guard interval than channel delay spread of channel between symbol. However, the multi-path delay of the channel to be serious with the guard interval can not eliminate ISI. In this case, using the equalizer must compensate. Especially, use of equalizer is need absolutely as data rate becomes high speed. In this paper, we analyze the BER performance with pre-equalization for MIMO-OFDM over fading channel. The results of this paper can be applied to MIMO-OFDM system with equalization.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.89-98
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• 2010

The enterprise system is becoming more complex and larger. With the changes of the times, the system is developing to object-oriented programming method(OOP). However, the same code inserts to the core class repetitiously in the OOP, that causes a decrease in productivity and a trouble of application of another requirement. To solve this weak point, we propose a weaving mechanism what applies to metadata and crosscutting concern. For a class optimization and an integration between different languages, we take the following way. This paper uses three ways, those are, metadata generation using reflection, transformation to Abstract Syntax Tree, and mapping through crosscutting information specified XML. Through the proposed theory, class optimization can be accomplished by solving a functional decentralization and a confusion of codes.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.169-177
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• 2011

As demand for efficiency in handling dynamic XML data grows, new dynamic XML labeling schemes have been researched. The key idea of the dynamic XML labeling scheme is to find ancestor-descendent-sibling relationships and to minimize memory space to store total label, response time and range of relabeling incurred by update operations. The prime number labeling scheme is a representative scheme which supports dynamic XML documents. It determines the ancestor-descendant relationships between two elements by a simple divisibility test of labels. When a new element is inserted into the XML data using this scheme, it does not change the label values of existing nodes. However, since each prime number must be used exclusively, labels can become significantly large. Therefore, in this paper, we introduce a novel technique to effectively reduce the problem of label overflow. The suggested idea is based on tree decomposition. When label overflow occurs, the full tree is divided into several sub-trees, and nodes in each sub-tree are separately labeled. Through experiments, we show the effectiveness of our scheme.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.6
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• pp.746-760
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• 1998

In this paper, an adaptive RSSD(reduced-state sequence detection) receiver is proposed for the purpose of reducing the complexity and decision delay of the adaptive MLSD(maximum-likelihood sequence detection) receiver in the mobile satellite channel. The RSSD receiver reconstructs the trellis with a reduced number of states. The performance degradation due to the reduced states is compensated by modifying the branch metric calculation which uses the symbols in each path memory to estimate the residual ISI(intersymbol interference) terms. The structure of the proposed adaptive RSSD is a modified RSSD utilizing a per-survivor processing as well as the symbol-aided method and a channel estimation using the tentative data sequences. The complexity and performance of the proposed adaptive RSSD are controlled by the number of system states and ISI cancelers and the inserting period of the known symbols. In spite of a suboptimal alternative receiver compared to the adaptive MLSD receiver, the proposed adaptive RSSD receiver is able to reduce the complexity significantly and track the time-varying channel fast and reliably.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.965-970
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• 2010

Because of a large number of subcarriers, the high PAPR(Peak-to-Average Power Ratio) is the major drawback of NC-OFDM system used for wireless communication system. Comb type pilot assignment is more efficient and lower computational complexity for the channel estimation than the block type pilot. However, even if the CAZAC(Constant Amplitude Zero Autocorrelation) matrix transform is used for the PAPR reduction of the data symbols, PAPR increases when the pilot is inserted in comb type with the data symbols. Therefore, in this paper, we additionally use a new SLM technique in order to lower the PAPR again even in the comb type pilot. Also, a new SLM technique suggested in this paper does not need any additional bandwidth for sending selection information for SLM. This combined method has good PAPR reduction performance and efficient data transmission.

• Journal of the Korea Computer Industry Society
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• v.3 no.7
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• pp.921-926
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• 2002

B+-Tree is the most popular indexing method in DBMS to manage large size data in more efficiency. However the existing B+-Tree has shortcomings in there is overhead on DISK/IO when the first time of constructing DB or of making Index, and it lessens the concurrency if there are frequent delete operations so that the index structure also should be changed frequently. To solve these problems almost DBMS is using batch construction method and lazy deletion method. But to apply B+-Tree, which is using batch construction method and lazy deletion method, into DBMS the technique for controlling and recovering concurrency is necessary, but its researching is still unsatisfactory so that there is a problem on applying it into actual systems. On this paper I suggest the technique for controlling and recovering concurrency how to implement the batch construction method and the lazy deletion method in actual DBMS. Through the suggested technique there is no cascade rollback by using Pending list, it enhances the concurrency by enabling insertion and deletion for base table on every reconstruction, and it shortens transaction response time for user by using system queue which makes the batch constructing operation is processed not in user's transaction level but in system transaction level.