• 정보처리학회논문지A
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• 제15A권6호
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• pp.325-334
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• 2008

플래시 메모리는 크기가 작고 적은 전력을 사용하며 충격에 강하기 때문에 휴대폰, MP3 플레이어, PDA와 같은 이동 기기에 널리 사용되고 있다. 또한, 노트북과 개인용 컴퓨터에서 사용하던 하드디스크를 플래시 메모리로 교체하려는 시도도 진행되고 있다. 최근에는 플래시 메모리 저장 시스템에서 대용량의 데이터를 효율적으로 검색하기 위한 플래시 메모리용 $B^+$-트리 인덱스를 개발하려는 연구가 이루어지고 있다. 이러한 연구는 $B^+$-트리에 키의 삽입 또는 삭제 시 발생하는 "덮어쓰기"를 최소화하는데 초점을 두고 있다. 그러나 이것뿐만 아니라 하나의 $B^+$-트리 노드에 할당되는 물리적 페이지의 크기도 $B^+$-트리 성능에 영향을 줄 수 있다. 본 논문에서는 다양한 실험을 통해 노드 크기에 따른 $B^+$-트리의 구축 성능, 검색 성능, 그리고 저장 공간 사용량을 비교 및 분석한다. 노드에 키 삽입 시 정렬 및 비정렬 알고리즘을 제시하며, 또한 효율적인 노드 검색을 위한 적절한 인덱스 노드 헤드 구조를 제안한다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.63-64
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• 2012

파이로 작동기구(PAD)는 고에너지 재료를 원격으로 폭발시켜 기구를 작동시키는 부품으로서 지금까지 이에 대한 설계는 주로 경험에 의해 이뤄졌다. 본 연구에서는 PAD의 작동 메커니즘을 해석적으로 모델링하는 효과적 방법을 개발하고 이를 설계에 활용하고자 한다. 해석모델은 서로 다른 해석특성을 가지는 세가지 순차적 스텝으로 구성되며 이들을 연계하여 통합 해석을 수행한다. 첫째 스텝은 작동기에서의 폭발 및 이로 인한 생성된 압력거동 해석, 둘째는 이러한 압력에 의해 피스톤을 작은 구멍 속으로 밀어넣는 압착거동 해석, 셋째는 피스톤 끝단에 있는 커터에 의해 박막을 관통하는 해석이며, 이로 인해 최종적으로 박막이 절개되면서 소기의 임무를 완성하게 된다. 본 발표에서는 이에 대한 개략적 소개와 일부 진행된 선행연구 결과를 소개한다.

• 국제초고층학회논문집
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• 제10권4호
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• pp.265-283
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• 2021

To ensure that fire induced collapse of a building is prevented it is important to understand the sequence of events that can lead to this event. In this paper, the initiation of collapse mechanisms of generic a multi-storey steel frame subjected to vertical and horizontal travelling fires are analysed computationally by tracking the formation of plastic hinges in the frame and generation of fire induced loads. Both uniform and travelling fires are considered. In total 58 different cases are analysed using finite element software LS-DYNA. For the frame examined with a simple and generic structural arrangement and higher applied fire protection to the columns, the results indicate that collapse mechanisms for singe floor and multiple floor fires can be each split into two main groups. For single floor fires (taking place in the upper floors of the frame (Group S1)), collapse is initiated by the pull-in of external columns when heated beams in end bays go into catenary action. For single floor fires occurring on the lower floors(Group S2), failure is initiated (i.e. ultimate strain of the material is exceeded) after the local beam collapse. Failure in both groups for single floor fires is governed by the generation of high loads due to restrained thermal expansion and the loss of material strength. For multiple floor fires with a low number of fire floors (1 to 3) - Group M1, failure is dominated by the loss of material strength and collapse is mainly initiated by the pull-in of external columns. For the cases with a larger number of fire floors (5 to 10) - Group M2, failure is dominated by thermal expansion and collapse is mainly initiated by swaying of the frame to the side of fire origin. The results show that for the investigated frame initiation of collapse mechanisms are affected by the fire type, the number of fire floors, and the location of the fire floor. The findings of this study could be of use to designers of buildings when developing fire protection strategies for steel framed buildings where the potential for a multifloor fire exists.

• Journal of Microbiology and Biotechnology
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• 제31권9호
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• pp.1191-1199
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• 2021

Enteropathogenic Escherichia coli (EPEC), which belongs to the attaching and effacing diarrheagenic E. coli strains, is a major causative agent of life-threatening diarrhea in infants in developing countries. Most EPEC isolates correspond to certain O serotypes; however, many strains are non-typeable. Two EPEC strains, EPEC001 and EPEC080, which could not be serotyped during routine detection, were isolated. In this study, we conducted an in-depth characterization of their putative O-antigen gene clusters (O-AGCs) and also performed constructed mutagenesis of the O-AGCs for functional analysis of O-antigen (OAg) synthesis. Sequence analysis revealed that the occurrence of O-AGCs in EPEC001 and E. coli O132 may be mediated by recombination between them, and EPEC080 and E. coli O2/O50 might acquire each O-AGC from uncommon ancestors. We also indicated that OAg-knockout bacteria were highly adhesive in vitro, except for the EPEC001 wzy derivative, whose adherent capability was less than that of its wild-type strain, providing direct evidence that OAg plays a key role in EPEC pathogenesis. Together, we identified two EPEC O serotypes in silico and experimentally, and we also studied the adherent capabilities of their OAgs, which highlighted the fundamental and pathogenic role of OAg in EPEC.

• 한국육종학회지
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• 제41권4호
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• pp.397-402
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• 2009

Self-incompatibility (SI) prevents self-fertilization by inhibiting the pollen tube growth of self-pollen. Molecular analysis has revealed that the S locus comprises a number of genes, such as the S-locus glycoprotein (SLG), the S-locus receptor kinase (SRK), and SP11 (SCR). Although molecular markers related to those genes have been developed, a simple S-haplotype detecting method has not been reported due to the highly polymorphic and relatively small coding regions. In this study, the sequence characterized amplified region (SCAR) markers were used to establish an efficient radish genotyping method. We identified the S-haplotypes of 192 radish accessions using 19 different markers, which proved to be highly reliable. The accessions were assigned to 17 types of S-haplotypes, including 8 types of SRKs and 9 types of SLGs. Since the developed SCAR markers are based on their gene sequences, we could easily identify the S-haplotypes by a single specific band, with the highest frequencies detected for SLG 5, SRK 1, and SLG 1, in order. Among the tested markers, the SLG 1, SRK 1, and SRK 5 markers exhibited high reliability, compared to phenotypic results. Furthermore, we identified the seven types of unreported SLGs using SLG Class -I and -II specific markers. Although the developed SCAR markers still need to be improved for the genotyping of all S-haplotypes, these markers could be helpful for monitoring inbred lines, and for developing the MAS in radish breeding programs.

• 한국콘텐츠학회논문지
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• 제19권2호
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• pp.605-618
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• 2019

본 연구는 2012년 이후 10개 지방자치단체가 제정한 '시민복지기준'의 개념, 제정과정, 분야와 내용 및 이에 근거하여 독자적으로 실시하는 지역사회복지사업 등을 비교분석하여 다양한 지방자치단체들이 향후 시민복지기준을 제정할 경우 필요한 제정 방식과 방향을 제시하고자 한다. 이를 위하여 본 연구는 먼저, 시민복지기준 개념을 시작부터 현재 우리나라에서의 이해를 역사적으로 분석하고, 10개 지자체가 제정한 시민복지기준의 개념을 분석하였다. 또한, 본 연구는 10개 지자체에서 지방자치제도와 주민참여라는 관점에서 실시된 민관협력방식의 시민복지기준 제정과정, 분야와 내용을 비교분석하였다. 이러한 비교분석을 통해 본 연구는 다른 지자체들이 시민복지기준을 제정할 경우 고려해야 하는 몇 가지 원칙들을 제시하였다. 마지막으로, 본 연구는 지자체의 시민복지기준 제정은 달성하고자 하는 단기 최저기준과 중기 적정기준을 구분하여 이를 실현할 수 있는 구체적 사업을 개발하고, 사업을 실시하기 위한 예산지원도 필요한 시민사회단체, 연구기관, 지자체 집행부, 의회 등이 함께 해야 하는 중장기 민관협력 프로젝트라는 것을 인식하는 것을 지적하였다.

• Parasites, Hosts and Diseases
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• 제56권6호
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• pp.559-565
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• 2018

The identification and characterization of pathogenic and zoonotic tick-borne diseases like granulocytic anaplasmosis are essential for developing effective control programs. The differential diagnosis of pathogenic Anaplasma phagocytophilum and non-pathogenic A. phagocytophilum-like Anaplasma spp. is important for implementing effective treatment from control programs. The objective of the present study was to investigate the prevalence of Anaplasma spp. in horses in Korea by nucleotide sequencing and restriction enzyme fragment length polymorphism assay. Of the 627 horses included in the study, only 1 (0.2%) was infected with A. phagocytophilum. Co-infection with A. phagocytophilumlike Anaplasma spp. was not detected in the study. The 16S rRNA sequence of A. phagocytophilum was similar (99.5-100%) to A. phagocytophilum 16S rRNA isolated from horses in other countries. PCR adapted to amplify A. phagocytophilum groEL and msp2 genes failed to generate amplicons, suggesting genetic diversity in these genes. This study is the first molecular detection of A. phagocytophilum in horses in Korea. Human granulocytic anaplasmosis and animal infection of A. phagocytophilum have been reported in Korea recently. Because of vector tick distribution, global warming, and the increase of the horse industry, horses should be considered as a potential reservoir for A. phagocytophilum, and cross infectivity should be evaluated even though a low prevalence of infection was detected in this study. Furthermore, continuous surveillance and effective control measures for A. phagocytophilum should be established to prevent disease distribution and possible transmission to humans.

• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.127-140
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• 2019

Since 1990, many nucleic acid expression platforms consisting of DNA or RNA have been developed. However, although RNA expression platforms have been relatively neglected, several such platforms capped at the 5' end of RNA by an anti-reverse cap analog have now been developed. At the same time, the capping reaction is a bottleneck in the production of such platforms, with high cost and low efficiency. Here, we investigated several viral and eukaryotic internal ribosome entry sites (IRESs) to develop an optimal RNA expression platform, because IRES-dependent translation does not require a capping step. RNA expression platforms constructed with IRESs from the 5' untranslated regions of the encephalomyocarditis virus (EMCV) and the intergenic region of the cricket paralysis virus (CrPV) showed sufficient expression efficiency compared with cap-dependent RNA expression platforms. However, eukaryotic IRESs exhibited a lower viral IRES expression efficiency. Interestingly, the addition of a poly(A) sequence to the 5' end of the coxsackievirus B3 (CVB3) IRES (pMA-CVB3) increased the expression level compared with the CVB3 IRES without poly(A) (pCVB3). Therefore, we developed two multiexpression platforms (termed pMA-CVB3-EMCV and pCrPV-EMCV) by combining the IRESs of CVB3, CrPV, and EMCV in a single-RNA backbone. The pMA-CVB3-EMCV-derived RNA platform showed the highest expression level. Moreover, it clearly exhibited expression in mouse muscles in vivo. These RNA expression platforms prepared using viral IRESs will be useful in developing potential RNA-based prophylactic or therapeutic vaccines, because they have better expression efficiency and do not need a capping step.

• 대한수의학회지
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• 제61권2호
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• pp.13.1-13.8
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• 2021

Mammalian reovirus (MRV) causes respiratory and intestinal disease in mammals. Although MRV isolates have been reported to circulate in several animals, there are no reports on Korean MRV isolates from wildlife. We investigated the biological and molecular characteristics of Korean MRV isolates based on the nucleotide sequence of the segment 1 gene. In total, 144 swabs from wild animals were prepared for virus isolation. Based on virus isolation with specific cytopathic effects, indirect fluorescence assays, electron microscopy, and reverse transcription-polymerase chain reaction, only one isolate was confirmed to be MRV from a Korean roe deer (Capreolus pygargus). The isolate exhibited a hemagglutination activity level of 16 units with pig erythrocytes and had a maximum viral titer of 10^5.7 50% tissue culture infectious dose (TCID₅₀)/mL in Vero cells at 5 days after inoculation. The nucleotide and amino-acid sequences of the partial segment S1 of the MReo2045 isolate were determined and compared with those of other MRV strains. The MReo2045 isolate had nucleotide sequences similar to MRV-3 and was most similar (96.1%) to the T3/Bat/Germany/342/08 strain, which was isolated in Germany in 2008. The MReo2045 isolate will be useful as an antigen for sero-epidemiological studies and developing diagnostic tools.

• 한국수학교육학회지시리즈A:수학교육
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• 제60권1호
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• pp.111-131
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• 2021

이 연구는 수학 교사들이 교과서 등으로 구현되는 교육과정을 어떻게 이해하여 활용하고자 의도하는가를 탐색하고자 한다. 이를 위해서, 교사들이 교과서 내용을 수업에 적용하는 의도와 목적을 파악하기 위한 설문검사 문항을 개발하였으며 25명의 교사들이 검사에 참여하였다. 자료 분석 결과로, 첫째, 연구 참여 교사들은 대체로 교과서의 내용을 그대로 수업에 활용하려는 경향을 드러낸다. 둘째, 교과서의 문제를 수정하거나 보완을 시도하는 경우에 그 결과물이 학생들의 수학적 사고 능력을 촉진하는 과제의 특성을 포함하는 단계에는 이르지 못하는 것으로 보인다. 셋째, 대체로 교사들은 학생의 수학적 역량을 개발을 목적으로 두기보다는 평가 준거로서 교과서를 활용하고자 의도하였다. 수학 교사들은 수업 실행에 있어서 교과서의 내용을 해석하여 능동적으로 수업에 활용하기 보다는 교과서 내용을 그대로 수용하여 충실히 따르고자 의도하는 것으로 나타났다.