• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.66-69
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• 2000

In this paper, we propose a progressive transmission of a video using a 2$\times$2$\times$2 DCT First of all, the video data is transformed into multiresolution represented video data using a 2$\times$2$\times$2 DCT. Then. it is represented by a 3-D EZT(Embedded Zero Tree) coding fur the progressive transmission with a bit-rate scalability. The proposed progressive transmission algorithm needs much less computations and buffer memories than the higher-order convolution based wavelet filter. Also, since the 2$\times$2$\times$2 DCT requires independent local computations, parallel processing can be applied.

• Journal of Information Processing Systems
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• v.11 no.3
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• pp.389-405
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• 2015

Most traditional database systems exploit a record-oriented model where the attributes of a record are placed contiguously in a hard disk to achieve high performance writes. However, for read-mostly data warehouse systems, the column-oriented database has become a proper model because of its superior read performance. Today, flash memory is largely recognized as the preferred storage media for high-speed database systems. In this paper, we introduce a column-oriented database model based on flash memory and then propose a new column-aware flash indexing scheme for the high-speed column-oriented data warehouse systems. Our index management scheme, which uses an enhanced $B^+$-Tree, achieves superior search performance by indexing an embedded segment and packing an unused space in internal and leaf nodes. Based on the performance results of two test databases, we concluded that the column-aware flash index management outperforms the traditional scheme in the respect of the mixed operation throughput and its response time.

• Annual Conference of KIPS
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• 2004.05a
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• pp.519-522
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• 2004

자바는 현재 가장 널리 사용되는 범용 프로그래밍 언어중 하나로 컴파일러에 의해 중간언어인 바이트코드로 변환되며 JVM(Java Virtual Machine)에 의해 실행되는 플랫폼 독립적인 언어이다. SIL(Standard Intermediate Language)은 Microsoft사의 .NET 언어와 SUN사의 Java 언어 등을 모두 수용할 수 있는 임베디드 시스템을 위한 중간언어로 가상기계인 EVM(Embedded Virtual Machine)에서 실행된다. 본 논문에서는 자바 프로그램을 컴파일하여 생성된 클래스 파일에서 Oolong 코드를 추출하고 추출된 Oolong 코드를 EVM의 SIL 코드로 변환하여 자바로 구현된 프로그램이 EVM에서 실행되도록 하는 Bytecode-to-SIL 번역기 시스템을 구현하였다. 그리고 본 번역기 시스템을 다른 플랫폼에 용이하게 설치하기 위한 재목적성(retargetability)을 위해 단일패스(one-pass)을 사용하는 기존의 번역기들과 달리 AST를 이용한 컴파일러 기법을 사용하여 AST가 가지고 있는 정보에 대해 최적화 작업을 수행하여 보다 효과적인 코드 변환을 할 수 있도록 설계하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.706-715
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• 2004

In this paper, to decide the watermark embedding positions and embed the watermark we use the subband tee structure which is presented in the wavelet domain and the edge information in the spatial domain. The significant frequency region is estimated by the subband searching from the higher frequency subband to the lower frequency subband. LH1 subband which has the higher frequency in tree structure of the wavelet domain is divided into 4${\times}$4 submatrices, and the threshold which is used in the watermark embedding is obtained by the blockmatrix which is consists by the average of 4${\times}$4 submatrices. Also the watermark embedding position, Keymap is generated by the blockmatrix for the energy distribution in the frequency domain and the edge information in the spatial domain. The watermark is embedded into the wavelet coefficients using the Keymap and the random sequence generated by LFSR(Linear feedback shift register). Finally after the inverse wavelet transform the watermark embedded image is obtained. the proposed watermarking algorithm showed PSNR over 2㏈ and had the higher results from 2％ to 8％ in the comparison with the previous research for the attack such as the JPEG compression and the general image processing just like blurring, sharpening and gaussian noise.

• Journal of Digital Contents Society
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• v.9 no.3
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• pp.471-481
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• 2008

Test scheduling considering power dissipation is an effective technique to reduce the testing time of complex SoCs and to enhance fault coverage under limitation of allowed maximum power dissipation. In this paper, a modeling technique of test resources and a test scheduling algorithm for efficient test procedures are proposed and confirmed. For test resources modeling, two methods are described. One is to use the maximum point and next maximum point of power dissipation in test resources, the other one is to model test resources by partitioning of them. A novel heuristic test scheduling algorithm, using the extended-tree-growing-graph for generation of maximum embedded cores usable simultaneously by using relations between test resources and cores and power-dissipation-changing-graph for power optimization, is presented and compared with conventional algorithms to verify its efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.393-401
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• 2013

Most traditional databases exploit record-oriented storage model where the attributes of a record are placed contiguously in hard disk to achieve high performance writes. However, for search-mostly datawarehouse systems, column-oriented storage has become a proper model because of its superior read performance. Today, flash memory is largely recognized as the preferred storage media for high-speed database systems. In this paper, we introduce fast column-oriented database model and then propose a new column-aware index management scheme for the high-speed column-oriented datawarehouse system. Our index management scheme which is based on enhanced $B^+$-Tree achieves high search performance by embedded flash index and unused space compression in internal and leaf nodes. Based on the results of the performance evaluation, we conclude that our index management scheme outperforms the traditional scheme in the respect of the search throughput and response time.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.12
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• pp.653-662
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• 2016

This paper describes a test case generation algorithm for Simulink/Stateflow models based on the Rapidly exploring Random Tree (RRT) algorithm that has been successfully applied to path finding. An important factor influencing the performance of the RRT algorithm is the metric used for calculating the distance between the nodes in the RRT space. Since a test case for a Simulink/Stateflow (SL/SF) model is an input sequence to check a specific condition (called a test target in this paper) at a specific status of the model, it is necessary to drive the model to the status before checking the condition. A status maps to a node of the RRT. It is usually necessary to check various conditions at a specific status. For example, when the specific status represents an SL/SF model state from which multiple transitions are made, we must check multiple conditions to measure the transition coverage. We propose a unique distance calculation metric, based on the observation that the test targets are gathered around some specific status such as an SL/SF state, named key nodes in this paper. The proposed metric increases the probability that an RRT is extended from key nodes by imposing penalties to non-key nodes. A test case generation algorithm utilizing the proposed metric is proposed. Three models of Electrical Control Units (ECUs) embedded in a commercial vehicle are used for the performance evaluation. The performances are evaluated in terms of penalties and compared with those of the algorithm using a typical RRT algorithm.

• The KIPS Transactions:PartB
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• v.9B no.1
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• pp.57-66
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• 2002

In this paper, we propose a method for the improvement of EZW encoding algorithm. The EZW algorithm encodes wavelet coefficients using 4 symbols such as POS(POsitive), NEG(NEGative), IZ(Isolated Zero), and ZTR(ZeroTreeRoot) which are determined by the significance of wavelet coefficients. In this paper, we applied threshold to wavelet coefficients to improve the EZW algorithm. The coefficients below the threshold are adjusted to zero to generate more ZTR symbols in the encoding process. The overall EZW image compression system is constructed using run-length coding and arithmetic coding. The system shows remarkable results for various images. We finally present experimentation results.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.182-188
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• 2007

모바일 음악 재생 장치의 보급이 활성화 되면서 모바일 환경에서 음악을 즐기고자 하는 욕구가 확대되었다. 모바일 음악 재생 장치의 저장 공간이 확대되어 한번에 많은 곡을 보유하게 되었지만, 실제적으로 많은 곡 중에서 자신이 원하는 곡을 쉽게 찾을 수 있는 방법이 존재하지 않고 있다. 이런 문제들을 해결하기 위해 해당 음악 고유의 Metadata를 활용하여 쉽게 찾고자 하는 경향이 있지만, 현재까지는 단순한 사용자 인터페이스만 제공하고 있다. 각각의 음악은 음악 고유의 Context도 가지게 되며, 사용자의 음악 감상 로그에 의해 생성되는 개인화 Context 및 같은 음악을 즐기는 다른 사용자들에 의해 생성되는 Social Context등으로 하나의 음악과 관련된 Context가 증가되는 추세에 있다. 이와 같이 추가되는 Context들은 음악을 탐색하는데 있어 효과적인 수단이 제공되어야 하지만 모바일 음악 재생장치에 있는 음악 탐색 프로그램은 새롭게 추가되는 Context 에 의한 효과적으로 대응하지 못하고 있다. 이러한 문제점을 해결하기 위해서 모바일 장치에 Embedded Database Engine을 장착하여 동적 트리 생성/탐색을 통한 Context 기반 연관 음악 탐색 방법을 제안하게 되었다. 본 논문에서는 새롭게 고안된 음악 탐색 방법에 대하여 3가지 사항에 대해서 제시하였다. 첫째, 새로운 Context추가에 대한 동적 메뉴 추가 방법을 제시하였다. 둘째, 실제로 새롭게 추가된 사용자 인터페이스에 대해서 알아보았으며, 마지막으로 제시된 방법이 얼마나 효과적인가를 계산하여 일반화 하였다.

• Journal of Forest and Environmental Science
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• v.24 no.3
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• pp.143-149
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• 2008

We conduct economic analysis of the snow damage on sugi (Cryptomeria japonica) forest stands in Toyama Prefecture, Japan. We utilize a single tree and distant independent growth simulator called "Silv-Forest." With this growth simulator, we developed an optimization model by dynamic programming, called DP-Silv (Dynamic Programming Silv-Forest). The MS-PATH (multiple stage projection alternative technique) algorithm was embedded as a searching algorithm of dynamic programming. The height / DBH ratio was used to constrain the thinning regime for snow damage protection. The optimal rotation age turned out to be 65 years for the non-restricted case, while it was 50 years for the restricted case. The difference in NPV of these two cases as the induced costs ranged from 179,867 to 1,910,713yen/ha over the rotation age of 20 to 75 years. Under the optimal rotation of 65 years, the cost became 914,226 yen/ha. The estimated annual payment based on the difference in NPV, was from 9,869 yen/ha/yr to 85,900 yen/ha/yr. All in all, 10,000 yen/ha/yr to 20,000 yen/ha/yr seems to cover the payment from the rotation age of 35 to 75 years.