• Membrane and Water Treatment
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• 제11권1호
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• pp.79-85
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• 2020

A single-stage deammonification with a sequencing batch reactor (SBR) that simultaneous nitritation, anaerobic ammonia oxidation (anammox), and denitrification (SNAD) occur in one reactor has been widely applied for sidestream of wastewater treatment plant. For the stable and well-balanced SNAD, a feeding strategy of influent wastewater is one of the most important operating factors in the single-stage deammonification SBR. In this study, single-stage deammonification SBR (working volume 30L) was operated to treat a high-strength ammonium wastewater (1200 mg NH₄⁺-N/L) with different feeding strategies (single feeding and nine-step feeding) under the condition without COD. Each cycle of the step feeding involved 6 sub-cycles consisted of aerobic and anoxic periods for partial nitritation (PN) and anammox, respectively. Contrary to unstable performance in the single feeding, the step feeding showed better deammonification performance (0.565 kg-N/m³/day). Under the condition with COD, however, the nitrogen removal rate (NRR) decreased to 0.403 kg-N/m³/day when the Nine-step feeding strategies had an additional denitrification period before sub-cycles for PN and anammox. The NRR was recovered to 0.518 kg-N/m³/day by introducing an enhanced multiple-step feeding strategy. The strategy had 50 cycles consisted of feed, denitrification, PN, and anammox, instead of repeated sub-cycles for PN and anammox. The multiple-step feeding strategy without sub-cycle showed the most stable and excellent deammonification performance: high nitrogen removal efficiency (98.6%), COD removal rate (0.131 kg-COD/m³/day), and COD removal efficiency (78.8%). This seemed to be caused by that the elimination of the sub-cycles might reduce COD oxidation during aerobic condition but increase the COD utilization for denitrification period. In addition, among various sensor values, the ORP pattern appeared to be applicable to monitor and control each reaction step for deammonification in the multiple-step feeding strategy without sub-cycle. Further study to optimize the number of multiple-step feeding is still needed but these results show that the multiple-step feeding strategy can contribute to a well-balanced SNAD for deammonification when treating high-strength ammonium wastewater with COD in the single-stage deammonification SBR.

• 한국통신학회논문지
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• 제25권4B호
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• pp.725-733
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• 2000

본 논문에서는 MPEG-4의 텍스처 부호화시 변형된 경계 블록 병합 기법을 제안하였다. 경계 블록 병합 기법의 전처리 과정으로 VOP를 나누는 위치를 조절하여 병합 시 부호화해야 할 블록의 수가 최소가 되는 점을 찾아 이를 기준으로 VOP를 다시 분할하는 최적화된 영역 분할 방법을 제안하였다. 또한, 객체의 모양이 복잡한 경우에는 +90。 회전과 -90。 회전 병합을 추가함으로써 병합의 가능성을 높일 수 있다. 따라서 본 논문에서는 180。 회전 병합, +90。 회전 병합 그리고 -90。 회전 병합의 순서로 병합을 하는 다중 회전 병합을 제안하였다. 기존의 경계 블록 병합 기법에서는 병합이 되는 두 블록이 상관성이 적다면 큰 패딩의 효과를 기대할 수가 없게 된다. 따라서 본 논문에서는 병합을 해 준 후에 블록의 내용을 기반으로 패딩을 해 주었다. 제안한 방식은 기존의 경계 블록 병합 기법에 비해 동일 PSNR 하에서 약 5∼8(%) 정도 부호화 비트량을 감소시켰다.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.302-309
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• 2005

Phytopathogenic Pectobacterium carotovorum subsp. carotovorum (Pcc) LY34 secretes multiple isozymes of the plant cell wall degrading enzyme endoglucanases. We have cloned a third cel gene encoding CMCase from Pcc LY34. The structural organization of the celC gene (AY188753) consisted of an open reading frame (ORP) of 1,116 bp encoding 371 amino acid residues with a signal peptide of 22 amino acids within the NH$_2$-terminal region of pre-CelC. The predicted amino acid sequence of CelC was similar to that of Peetobaeterium ehrysanthemi Cel8Y (AF282321). The CelC has the conserved region of the glycoside hydrolase family 8. The apparent molecular mass of CelC was calculated to be 39 kDa by CMC-SDS-PAGE. The cellulase­minus mutant of Pee LY34 was as virulent as the wild-type in pathogenicity tests on tubers of potato. The results suggest that the CelC of Pce LY34 is a minor factor for the pathogenesis of soft-rot.