• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1597-1599
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• 2007

In TFT-LCD, mura is a defect which degrades the display quality. The resistance difference between gate lines is the main cause of H-Block mura. Two methods could eliminate this defect. A thinner gate layer or gate fan-out pattern decrease mura level. H-Block mura has been reduced after implementing the new schemes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6C
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• pp.562-571
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• 2010

Forward error correction (FEC) coding schemes using iterative soft decision detection (SDD) information are mandatory in most of the next generation wireless communication system, in order to combat inevitable channel imparirnents. At the same time, space-time block coding (STBC) schemes are used for the diversity gain. Therefore, SDD information has to be fed into FEC decoder. In this paper, we propose efficient SDD methods for turbo-coded STBC system using high order modulation such as QAM. We present simulation results of various SDD schemes for turbo-coded STBC systems, and show that the proposed methods can provide almost approximating performance to maximum likelihood detection with much less computational load.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.103-114
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• 2012

The many DE based data hiding schemes and the many data hiding schemes based on Histogram shifting are researched in spatial domain. The data hiding scheme based on Histogram shifting have an advantage of low distortion of the stego image. But the capacity is low than other schemes. On the other hands, the DE based data hiding schemes have an advantage of high capacity. But the quality of the stego image is low. In this paper, new data hiding scheme which has the similar capacity but the increased quality of the stego image is proposed. The prediction error is divided into blocks to embed the secret data in this scheme. The prediction errors in the block are scanned before the secret data is embedded. If one prediction error is low than the threshold at least, the block is changed to embed the secret data. Otherwise the secret data is not embedded. The distortion of the stego image is minimized by this method. But the block that the secret data embedded is marked in location map. So the additional information to extract the secret data and recover the cover image is needed.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.06a
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• pp.889-893
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• 1996

• International Journal of Contents
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• v.6 no.4
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• pp.22-29
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• 2010

In flash memory, many previous garbage collection methods only merge blocks statically and do not consider the contents of buffer. These schemes may cause more unnecessary block erase operations and page copy operations. However, since flash memory has the limitation of maximum rate and life cycle to delete each block, an efficient garbage collection method to evenly wear out the flash memory region is needed. This paper proposes a memory compaction scheme based on block-level buffer for flash memory. The proposed scheme not only merges the data blocks and the corresponding log block, but also searches for the block-level buffer to find the corresponding buffer blocks. Consequently, unnecessary potential page copying operations and block erasure operations could be reduced, thereby improving the performance of flash memory and prolonging the lifetime of flash memory.

• Journal of applied mathematics & informatics
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• v.40 no.3_4
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• pp.531-543
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• 2022

The article proposed a new type of data relationship: Positive Boolean dependencies by groups on block and slice in the database model of block form, where instead of considering value pairs, we consider a group of p values (p ≥ 2). From this new concept, the article stated and demonstrated the equivalence of the three types of deduction, namely: deduction by logic, deduction by block with groups, deduction by block has no more than p elements with groups. Operations on blocks or slices performed for index attributes on blocks, the properties related to this new concept as theorem the equivalen of the three types of deduction, closure of set positive Boolean dependencies by groups and representation and tight representation set of positive Boolean dependencies by groups when the block degenerated into relation are true in the relational database model and also stated and proven in this paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.2
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• pp.344-352
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• 1997

This paper proposes an efficient lossless coding scheme for tree structured vector quantization (TSVQ) system which efficiently exploits inter-block correlation. The TSVQ index of the current block is adaptively arithmeticencoded depending on the indices of the previous blocks. This paper also presents a reductio method, which effectively resolve the memory problem which usually arises in many conditional entropy coding schemes. Simulation results show that the proposed scheme provides remarkable bitrate reduction by effectively exploiting not only linear but also non-linear inter-block correlation.

• Journal of Advanced Navigation Technology
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• v.8 no.1
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• pp.10-18
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• 2004

As a technique for high-quality multimedia service in down-link, the transmit diversity schemes using a orthogonal space-time block codes were proposed. But if the number of transmit antenna is three or more, it was impossible to obtain full diversity gain because of the decline of spectral efficiency. Accordingly, the quasi-orthogonal space-time block code that not required a additional bandwidth was proposed. But using a space-time block codes, the transmit diversity schemes were verified over quasi-static and frequency non-selective channels. Therefore, in this paper, we analyze the performance of OFDM systems, which a frequency selective channel equalized a frequency non-selective channel, adapting the quasi-orthogonal space-time block code, and compare they to the conventional orthogonal space-time block coded OFDM systems.

• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.1
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• pp.1-10
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• 2007

In recent few years, low-power electronics has been a leading drive for technology developments nourished by rapidly growing market share. Mobile DRAM, as a fundamental block of hand-held devices, is now becoming a product developed by limitless competition. To support application specific mobile features, various new power-reduction schemes have been proposed and adopted by standardization. Tightened power budget in battery-operated systems makes conventional schemes not acceptable and increases difficulty of the circuit design. The mobile DRAM has successfully moved down to 1.5V era, and now it is about to move to 1.2V. Further voltage scaling, however, presents critical problems which must be overcome. This paper reviews critical issues in mobile DRAM design and various circuit schemes to solve the problems. Focused on analog circuits, bitline sensing, IO line sensing, refresh-related schemes, DC bias generation, and schemes for higher data rate are covered.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12B
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• pp.2438-2446
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• 1999

Most of block based stereo pair compression schemes utilize the constant block size and searching area size for all the stereo pairs to find the best matching block. However, it is not efficient to use the same block size and size of searching area to all the stereo pairs, since each stereo pair has different disparity. In this Paper, we propose a method to calculate the total disparity of stereo pairs, and show how to determine the size of the block and searching area which are applied for the block based compression of the stereo pairs.