• New & Renewable Energy
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• v.18 no.4
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• pp.1-11
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• 2022

Landfill gas (LFG) generation characteristics in a construction waste landfill zone (block E) and mixed landfill zone (block A) were analyzed. During the period from October 2018 to April 2022, a total of 936×10³ and 1,001×10³ tons of waste were disposed in block E and block A, respectively. Out of this, 27.1% and 55.6% were biodegradable waste in block E and block A, respectively. The landfill masses of the two blocks were converted to be comparable. Then, the biodegradable waste and organic carbon were estimated by element analysis, biodegradable carbon by biochemical methane potential experiment (DC), and sulfate ion by acid decomposition. Results showed that biodegradable waste, organic carbon, biodegradable carbon, and sulfate ions in block A were 2.1, 1.6, 5.2, and 0.4 times greater than those in block E, respectively. The amount of LFG generated by block A was 4.8 times greater than that by block E. The average concentrations of methane (CH₄) were 60.8% and 60.9% in block E and block A, respectively, which were unrelated to the nature of disposed waste. The average concentrations of hydrogen sulfide (H₂S) were significantly high in block E (4,489 ppm) and block A (8,478 ppm). As the DC/SO₄^2- of block E and block A were 0.35 and 4.56, respectively, increase in DC/SO₄^2- caused increase in not only the total amount but also the concentration of H₂S generated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7C
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• pp.628-633
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• 2010

This paper proposes a block matching algorithm to improve the sub-block matching algorithm that uses partial sub-blocks being a great contribution to the block matching. Unlike the conventional algorithm using the one sub-block group the proposed algorithm uses two sub-block groups. The matching using the small group selects a candidate block to be a good possibility of a similar block with a small computation cost and the additional matching using the large group in the selected block decreases a wrong matching. Simulation results show that the proposed algorithm always has good image quality at the same computation cost as compared to the conventional algorithm and it has an outstanding performance at the matching using a few sub-blocks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.10
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• pp.2645-2652
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• 1996

In this paper wepropose a sub-block retransmission scheme for ARQ and hybrid ARQ schemes. When the cannel is quiet the sub-block retransmission scheme behaves like a conventional ARQ or hybrid ARQ scheme. As the channel is becoming noisy, the data block is dvided into small sub-blocks for transmission. Each sub-block is encoded for error control by an apprpriate shortened code and the code length of the shortened code is being adaptive to the corresponding channel BER. the reeived block is checked for errors sub-block by sub-block. The propsoed sub-block retransmission scheme provides improved throughput over conventional schemes by retransmitting only the naked sub-blocks in the occurrence of errors. An example of transferring ATM cells is considered for simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.655-658
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• 2005

This paper proposes a modified block matching algorithm which reduces an amount of matching computation by using only pixels contributing greatly to block matching. In consideration of algorithm implementation and additional information, the proposed algorithm divides a matching block into sub-blocks, selects some sub-blocks using their complexities, and execute the block mating with them. Simulation results show that the proposed algorithm performs a valid block matching with some sub-blocks.

• Communications of the Korean Mathematical Society
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• v.35 no.3
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• pp.917-925
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• 2020

It has been shown that the geometric mean A#B of positive definite Hermitian matrices A and B is the maximal element X of Hermitian matrices such that $$\(\array{A&X\\X&B}\)$$ is positive semi-definite. As an extension of this result for the 2 × 2 block matrix, we consider in this article the block matrix [[A#w_ijB]] whose (i, j) block is given by the Riemannian geodesics of positive definite Hermitian matrices A and B, where w_ij ∈ ℝ for all 1 ≤ i, j ≤ m. Under certain assumption of the Loewner order for A and B, we establish the equivalent condition for the parameter matrix ω = [w_ij] such that the block matrix [[A#w_ijB]] is positive semi-definite.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3C
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• pp.258-263
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• 2006

Each pixel in a matching block does not equally contribute to block matching and the matching error is greatly affected by image complexity. On the basis of the facts, this paper proposes a fast motion estimation algorithm using some sub-blocks selected by the image complexity. The proposed algorithm divides a matching block into 16 sub-blocks, computes the image complexity in every sub-block, executes partial block matching using some sub-blocks with large complexity, and detects a motion vector. The simulation results show that the proposed algorithm brings about negligible image degradation, but can reduce a large amount of computation in comparison with conventional algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1405-1409
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• 2004

This paper is studied new block mode decision algorithm for H.264/AVC. The fast block mode decision algorithm is consist of block range decision algorithm. The block range decision algorithm classifies the block over 8$\times$8 size or below for 16${\times}$16 macroblock to decide the size and type of sub blocks. As the sub blocks of 8$\times$8, 8r4, 4$\times$8 and 4$\times$4, which are the blocks below 8$\times$8 size, include important motion information, the exact sub block decision is required. RDC(RDO cost) is used as the matching parameter for the exact sub block decision. RDC is calculated with motion strength which is the mean value of neighbor pixels of each sub block. The sub block range decision reduces encoding arithmetic amount by 34.62% on the average more than the case not using block range decision. The block mode decision using motion strength shows improvement of PSNR of 0.05[dB].

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.24 no.3
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• pp.243-291
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• 2020

In this paper, multi-block generalized backward differentiation methods for numerical solutions of ordinary differential and differential algebraic equations are introduced. This class of linear multi-block methods is implemented as multi-block boundary value methods (MB₂ VMs). The root distribution of the stability polynomial of the new class of methods are determined using the Wiener-Hopf factorization of a matrix polynomial for the purpose of their correct implementation. Numerical tests, showing the potential of such methods for output of multi-block of solutions of the ordinary differential equations in the new approach are also reported herein. The methods which output multi-block of solutions of the ordinary differential equations on application, are unlike the conventional linear multistep methods which output a solution at a point or the conventional boundary value methods and multi-block methods which output only a block of solutions per step. The MB₂ VMs introduced herein is a novel approach at developing very large scale integration methods (VLSIM) in the numerical solution of differential equations.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.367-369
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• 2001

멀티미디어 환경의 발전에 따라 동영상에 대한 효과적인 검색 및 관리와 CG와 일반 영상의 합성을 위하여 영상 내의 카메라 동작 요소 검출 기법이 필요하다. 본 논문에서는 sub-block당 투영 영상을 이용만 카메라 동작 요소 검출 방법을 제안한다. 제안한 방법은 sub-block당 평균값을 이용만 투영 영상상에서 각 sub-block 내에서의 x, y 방향 이동 성분을 구하여 이를 통한 Optical flow를 얻는다. 제안하는 방법은 기존의 block-matching을 통하여 optical flow를 얻는 방법보다 계산량의 감소와 계산 속도의 증가를 나타낸다. 실험 결과에서는 제안하는 방법에 의하여 얻은 optical flow를 보여주며 예측도의 증가를 보여준다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1703-1708
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• 2005

This paper proposes a modified block matching algorithm which reduces an amount of matching computation by using only pixels contributing greatly to block matching. In consideration of algorithm implementation and additional informatirm, the proposed algorithm divides a matching block into sub-blocks, selects some sub-blocks using their complexities, and execute the block mating with them. Simulation results show that the proposed algorithm performs a valid block matching, diminishing computation cost.