• ETRI Journal
• /
• 제28권3호
• /
• pp.329-336
• /
• 2006

This paper investigates the problem of protecting multicast sessions in mesh wavelength-division multiplexing (WDM) networks against single link failures, for example, a fiber cut in optical networks. First, we study the two characteristics of multicast sessions in mesh WDM networks with sparse light splitter configuration. Traditionally, a multicast tree does not contain any circles, and the first characteristic is that a multicast tree has better performance if it contains some circles. Note that a multicast tree has several branches. If a path is added between the leave nodes on different branches, the segment between them on the multicast tree is protected. Based the two characteristics, the survivable multicast sessions routing problem is formulated into an Integer Linear Programming (ILP). Then, a heuristic algorithm, named the adaptive shared segment protection (ASSP) algorithm, is proposed for multicast sessions. The ASSP algorithm need not previously identify the segments for a multicast tree. The segments are determined during the algorithm process. Comparisons are made between the ASSP and two other reported schemes, link disjoint trees (LDT) and shared disjoint paths (SDP), in terms of blocking probability and resource cost on CERNET and USNET topologies. Simulations show that the ASSP algorithm has better performance than other existing schemes.

• Journal of Communications and Networks
• /
• 제8권2호
• /
• pp.212-219
• /
• 2006

In this paper, a new turbo codes-based hybrid automatic repeat request (TC-HARQ) scheme with segment selective repeat (SSR) is proposed. The main strategy is, upon retransmission, to repeat the data that are most important for the next round of decoding based on the distribution of residual errors after current decoding. The performance in terms of reliability and throughput is analyzed. To adapt to correlated fading channels where an inter-leaver is always employed before transmission, we further modify the SSR strategy so that data having experienced correlated deep fading are selected for retransmission. Finally, this proposed scheme is applied to the wideband code division multiple access (WCDMA) system under frequency selective fading channels. Simulation results demonstrate that in all single and multiple user cases, SSR-based TC-HARQ leads to significant throughput improvement with similar bit error rate (BER) performance as compared to type-I TC-HARQ.

• Journal of Microbiology and Biotechnology
• /
• 제4권4호
• /
• pp.264-269
• /
• 1994

To determine the nucleotide sequence of the ds RNA segment B containing the RNA dependent RNA polymerase (RdRp) gene of the DRT strain of infectious pancreatic necrosis virus (lPNV), the cDNA of the ds RNA segment B of the DRT strain of IPNV was synthesized using the reverse transcriptase (RT)-polymerase chain reaction (PCR) and its cDNA nucleotide sequence was determined. The DRT segment B was 2, 783 bp long and contained only a single long open reading frame (ORF) of 2, 535 bp in length. This ORF nucleotides encoded the VPl protein, the putative RdRp of IPNV. The VPl protein comsisted of 845 amino acids. The molecular weight of the RdRp, as deduced from the nucleotide sequence, is 94, 426. The nucleotide sequence of the ORF of the DRT showed 89.7% homology to the Jasper strain, but 80.8% to the Sp strain. The amino acid sequence of the ORF of the DRT sho.wed 97.6% homology to the Jasper strain, but 88.7% to the Sp strain. The conserved GTP-binding motif was detected in VPl protein.

• 한국컴퓨터정보학회논문지
• /
• 제13권6호
• /
• pp.1-12
• /
• 2008

본 논문에서는 카메라 회전에 의한 배경의 왜곡이 존재하는 환경에서 조명변화와 대상물체의 흔들림에도 강건한 에지 세그먼트 정합을 통한 이동물체 자동 검출방법을 제안한다. 이동물체 검출을 위한 기존의 연구는 카메라가 고정되어 있는 환경을 대상으로 한 연구가 주를 이루지만 응용분야의 확대로 카메라를 회전함으로써 하나의 카메라로 보다 넓은 영역을 커버할 수 있는 시스템에 대한 요구가 커지고 있다. 본 연구에서는 왜곡이 적은 에지세그먼트 기반 배경 파노라마 영상 생성 방안, 왜곡이 포함된 파노라마 영상에서 신속하게 현재 영상의 배경에지영상을 추출할 수 있는 에지특징 기반 GHT를 이용한 배경영상생성 방안, 시점의 차이와 왜곡을 극복하고 신뢰성 있게 이동 에지 세그먼트를 추출할 수 있는 에지 정합방안을 제안한다. 실험결과 제안한 방법은 조명 변화와 카메라의 흔들림에도 정확한 이동물체 검출이 가능함이 입증되었다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권7호
• /
• pp.2589-2609
• /
• 2021

Segment routing (SR) is a highly implementable approach for traffic engineering (TE) with high flexibility, high scalability, and high stability, which can be established upon existing network infrastructure. Thus, when a network failure occurs, it can leverage the existing rerouting methods, such as rerouting based on Interior Gateway Protocol (IGP) and fast rerouting with loop-free alternates. To better exploit these features, we propose a high-performance and easy-to-deploy method SRUF (Segment Routing under Uncertain Failures). The method is inspired by the Value-at-Risk (VaR) theory in finance. Just as each investment risk is considered in financial investment, SRUF also considers each traffic distribution scheme's risk when forwarding traffic to achieve optimal traffic distribution. Specifically, SRUF takes into account that every link may fail and therefore has inherent robustness and high availability. Also, SRUF considers that a single link failure is a low-probability event; hence it can achieve high performance. We perform experiments on real topologies to validate the flexibility, high-availability, and load balancing of SRUF. The results show that when given an availability requirement, SRUF has greater load balancing performance under uncertain failures and that when given a demand requirement, SRUF can achieve higher availability.

• Animal Systematics, Evolution and Diversity
• /
• 제39권4호
• /
• pp.176-211
• /
• 2023

Nine copepod species of the family Artotrogidae Brady, 1880 are described or redescribed from Korea. Included new species are two in the genus Artotrogus Boeck, 1859, one each in the genera Bradypontius Giesbrecht, 1895, Cryptopontius Giesbrecht, 1899, Neopontius Scott T., 1898 and Chejupontius n. gen., and two in the genus Sewellopontius Ummerkutty, 1966. Chejupontius n. gen. resembles Ascidipontius Kim I. H., 1996, Pulicitrogus Kim I. H., 1998, and Sewellopontius in having reduced armature of leg 1, but is distinguished from these and other genera of the family by the large, mediodistally expanded protopod of leg 5 and by a combination of characters exhibited in leg 1 that the first exopodal segment lacks an inner seta, the second exopodal segment lacks an outer spine, the third exopodal segment is armed with three spines plus one to three setae, and the second endopodal segment is armed with a single inner seta. Pteropontius cristatus Giesbrecht, 1895 known previously only from the Mediterranean Sea is redescribed, based on a newly collected specimen from Korea, and P. trimerus Kim I. H., 1996 is removed to the genus Sewellopontius. A short note is given for the epibiotic suctorian Thecacineta calix (Schroder, 1907) which was found attached to the antennule of a new copepod species.

• 대한치과교정학회지
• /
• 제45권1호
• /
• pp.20-28
• /
• 2015

Objective: The purpose of this study was to observe stress distribution and displacement patterns of the entire maxillary arch with regard to distalizing force vectors applied from interdental miniscrews. Methods: A standard three-dimensional finite element model was constructed to simulate the maxillary teeth, periodontal ligament, and alveolar process. The displacement of each tooth was calculated on x, y, and z axes, and the von Mises stress distribution was visualized using color-coded scales. Results: A single distalizing force at the archwire level induced lingual inclination of the anterior segment, and slight intrusive distal tipping of the posterior segment. In contrast, force at the high level of the retraction hook resulted in lingual root movement of the anterior segment, and extrusive distal translation of the posterior segment. As the force application point was located posteriorly along the archwire, the likelihood of extrusive lingual inclination of the anterior segment increased, and the vertical component of the force led to intrusion and buccal tipping of the posterior segment. Rotation of the occlusal plane was dependent on the relationship between the line of force and the possible center of resistance of the entire arch. Conclusions: Displacement of the entire arch may be dictated by a direct relationship between the center of resistance of the whole arch and the line of action generated between the miniscrews and force application points at the archwire, which makes the total arch movement highly predictable.

• 대한전자공학회논문지SD
• /
• 제42권8호
• /
• pp.15-26
• /
• 2005

본 논문에서는 효율적인 $GF(2^m)$ 멀티 세그먼트 곱셈 연산 구조를 제안하고 제안된 구조의 타원곡선 암호 프로세서 설계 응용을 연구한다. 제안된 멀티 세그먼트 곱셈 연산 구조는 유한체 크기 m에 비하여 아주 작은 워드 조합 곱셈기를 이용하여 부분곱을 계산하고 거의 모든 내부 버스는 워드 크기이며 m 비트 멀티플렉서와 m 비트 레지스터를 하나만 사용한다. 따라서 조합 곱셈기의 워드 크기 w를 줄이고 세그먼트 수 k를 크게 하여 전체 데이터패스 자원 사용량이 최소화할 수 있다. 제안된 곱셈기는 디지트 시리얼 곱셈기로 구현된 ECC 프로세서와 비교할 때 이론적으로 자원 효율성이 우수하다 암호 프로세서의 자원 사용량은 구현에 필요한 기본 하드웨어 요소 수뿐만 아니라 구성 요소들의 배치와 연결 상태에도 의존한다. 제안된 프로세서의 실질적인 자원사용량을 디지트 시리얼 곱셈기 기반 암호 프로세서와 비교하기 위하여 두 종류의 프로세서를 FPGA 상에 구현하였다. 실험 결과로 제안된 멀티 세그먼트 곱셈기 기반 EU 프로세서는 유사한 성능을 가지는 디지트 시리얼 곱셈기 기반 EU 프로세서보다 자원 사용면에서 2배 정도 우수함을 보였다.

• 한국생물물리학회:학술대회논문집
• /
• 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
• /
• pp.37-37
• /
• 1999

The influenza A viruses which are the most severe and common among the influenza viruses have 8 segmented RNA genomes Each RNA segment has highly conserved 3' and 5' terminal sequence except a single U\longrightarrowC variation especially in the 4 position of the 3' terminal of the 3 segments encoding own RNA polymerase.(omitted)

• Journal of Korean Neurosurgical Society
• /
• 제58권1호
• /
• pp.54-59
• /
• 2015

Objective : The aim of this prospective study was to evaluate the efficacy of bone cement-augmented percutaneous short segment fixation for treating Kummell's disease accompanied by severe osteoporosis. Methods : From 2009 to 2013, ten patients with single-level Kummell's disease accompanied by severe osteoporosis were enrolled in this study. After postural reduction for 1-2 days, bone cement-augmented percutaneous short segment fixation was performed at one level above, one level below, and at the collapsed vertebra. Clinical results, radiological parameters, and related complications were assessed preoperatively and at 1 month and 12 months after surgery. Results : Prior to surgery, the mean pain score on the visual analogue scale was $8.5{\pm}1.5$. One month after the procedure, this score improved to $2.2{\pm}2.0$ and the improvement was maintained at 12 months after surgery. The mean preoperative vertebral height loss was $48.2{\pm}10.5%$, and the surgical procedure reduced this loss to $22.5{\pm}12.4%$. In spite of some recurrent height loss, significant improvement was achieved at 12 months after surgery compared to preoperative values. The kyphotic angle improved significantly from $22.4{\pm}4.9^{\circ}$ before the procedure to $10.1{\pm}3.8^{\circ}$ after surgery and the improved angle was maintained at 12 months after surgery despite a slight correction loss. No patient sustained adjacent fractures after bone cement-augmented percutaneous short segment fixation during the follow-up period. Asymptomatic cement leakage into the paravertebral area was observed in one patient, but no major complications were seen. Conclusion : Bone cement-augmented percutaneous short segment fixation can be an effective and safe procedure for Kummell's disease.