Seismic responses due to the dynamic coupling between a primary structure and secondary system connected to a structure are analyzed in this study. The seismic responses are compared based on dynamic coupling criteria and according to the error level in the natural frequency, with the recent criteria being reliant on the error level in the spectral displacement response. The acceleration responses and relative displacement responses of a primary structure and a secondary system for a coupled model and two different decoupled models of two degrees-of-freedom system are calculated by means of the time integration method. Errors in seismic responses of the uncoupled models are reduced with the recent criteria. As the natural frequency of the secondary system increases, error in the natural frequency decreases, but seismic responses of uncoupled models can be underestimated compared to that of coupled model. Results in this paper can help determine dynamic coupling and predict uncoupled models’ response conservatism.

The purpose of this study was to explore how motivational factors affect Korean EFL secondary students’ motivated learning behavior using structural equation modeling (SEM). It further examined differences in the internal structure of L2 motivation over time. A total of 489 secondary school students participated in the study. Data were collected at two time points during an academic semester: in the beginning and at the end of the semester. Results of the SEM showed that students’ ideal L2 self was the strongest determinant of their motivated learning behavior at both time points for middle school students, whereas for high school students, ought-to L2 self had the strongest direct and significant impact on their motivated behavior in learning English throughout the semester. It was also found that both middle and high school students’ perceptions about the international posture of English and their parents’ involvement in English learning made indirect effects on their motivated behavior. Pedagogical implications and research suggestions are discussed.

본 연구는 식물사회학적 연구방법에 의해 추이대에 속하는 두륜산 일대의 삼림식생을 분류하고, 삼림식생단위와 환경과의 상관관계를 분석하여 온난화에 따른 식생의 수평적 변화를 구성종과 상관식생의 우점종을 통해 예측하는 것을 목적으로 수행하였다. 삼림식생은 졸참나무-굴참나무군락, 붉가시나무-황칠나무군락, 편백나무식재림 등 3개의 군락단위로 구분되었다. 각 삼림군락의 분포와 환경 요인들과의 상관 관계를 분석하였던 바, 모든 삼림군락에서 출현한 동백나무군강의 식별종, 구분종, 난온대성 낙엽활엽수림의 구성종 요소, 상관식생의 주요종을 통하여 낙엽활엽수림인 졸참나무-굴참나무군락은 굴참나무가 상대적으로 높은 출현율을 보이는 지역부터 점차 상록활엽수림으로 천이가 이루질 것으로 예측된다.

A polydnavirus, Cotesia plutella bracovirus (CpBV), encodes host translation inhibitory factors (HTIFs). Two HTIFs have been identified and named as CpBV15α and CpBV15β. HTIFs specifically inhibit host gene expression at post transcriptional level. This suggests that HTIFs can discriminate host mRNAs for their inhibition. To test this hypothesis, we chose a storage protein 1 (SP1) for a target and CpBV15β for non-target genes. Both target and non-target genes were constructed in a cloning vector by cloning their 5'UTR+ORF and in vitro transcribed. The capped partial mRNAs were in vitro translated using rabbit reticulocyte lysate in the presence or absence of HTIFs. Translation of SP1 mRNA was significantly inhibited by the HTIF, but those of CpBV15α and CpBV15β were not. We prepared chimeric mRNAs by exchanging 5'UTR and ORF of both target and non-target genes. Inhibitory activity of HTIFs was dependent on the 5'UTR structure. Target 5'UTR had more complicated secondary structure than non-target 5'UTR in terms of free energy required for unwinding. To identify the target molecule of HTIF to discriminate 5'UTR, an immunoprecipitation using HTIF antiserum was conducted. HTIF was co-precipitated with eIF4A that would be required for unwinding the secondary structure of mRNA. These results suggest that HTIF of CpBV can sequester host eIF4A, any mRNAs possessing complicated secondary structures in their 5'UTRs would be difficult to recruit initiation complex for efficient translation.

We amplified D1 and D3 expansion segments of the 28S ribosomal RNA from 10 Suanguina moxae populations found in Korea. The amplification of the D1-D3 expansion segments of 28S gene of all populations tested produced a single PCR product approximately 1.03kb in size, suggesting the lack of D1-D3 expansion region size polymorphism among populations. The secondary structure model of 28S expansion segments D2 and D3 for Subanguina Moxae was predicted based on free energy minimization with comparative sequence analysis and new sequence alignment was conducted based on predicted secondary structure model. The predicted model was compared with previous predicted models of plant and animal parasite nematode. This predicted secondary structure model will provide valuable information to allocate positional sequence homology and reconstruction of reliable phylogenetic trees.

The subfamily Hoplolaiminae included economically important plant parasitic nematodes and consisted of more than 400 species, all having the diagnostic characters of a strongly annulated cuticle and a large stylet. Among the Hoplolaiminae genera, the genus Hoplolaimus species include species such as H. columbus, and H. galeatus that cause serious damage to crops and turf grass in the Southeastern United States. Traditional identification of species has been approached by interspecific variation of phenotypic traits that rely on morphological and morphometric characters. However, these taxonomic criteria are sometimes not practical because of their limited ability to discriminate species among closely related groups due to overlapping of important taxonomic characters. The exact species identification is needed to control target nematode and also quarantine. Therefore, genetic studies for development of molecular diagnostics, population biology, and disease management are required. In recent years, many molecular diagnostic methods have been used for the identification of plant parasitic nematodes. Advanced molecular techniques have been used that test traditional identification methods. In our studies, Hoplolaimus species showed that high genetic divergence in rDNA sequence is combined with low morphological diversity. Based on genetic information, we developed multiplex PCR for H. columbus, H. galeatus, and H. magnistylus and successfully amplified mixed populations. In molecular phylogeny, the subfamily Hoplolaiminae is an important out‐group of the Heteroderidae, a notorious plant parasite nematode group. Molecular phylogeny of the Hoplolaiminae will help us understand of pathways of pathogenesis. In our phylogenetic analysis using D2 and D3 expansion segments of 28S gene, the molecular data supported morphological based taxonomic schemes. To reconstruct more reliable phylogenetic analysis, correct assignment of each nucleotide within multiple sequence alignment is an important step. Sequence alignments based on secondary structure have been proposed as new alternative methods to obtain this goal. We predicted the secondary structure of D2 and D3 domain using computational predictions method such as the minimization energy method and comparative sequence analysis (co‐variation). Predicted secondary structure included 18 species with two outgroup species, Globodera rostochiensis, Rotylenchulus reniformis. Consensus secondary structure was obtained from closely related and distantly related species. Phylogenetically informative characters were distributed in the stem region (86.7%). These results support the effectiveness of stem and loop regions for phylogenetic analysis of the Hoplolaiminae.

본 연구는 예비 중등교사들을 대상으로 지구 내부에서의 방사성 동위원소에 대한 예비 중등교사의 대안개념의 구조를 이해하는 것이다. 그들의 대안개념의 구조를 Lakatos의 방법론을 기준틀로 한 Niaz(1998)의 제안을 사용하여 분석하였다. 이 연구는 사범대학 과학교육과 3∼4학년 17명을 대상으로 하였다. 연구 방법으로는 개방형 질문지법(open-ended written questionnaire)을 사용하였다. 연구 결과, 예비 중등교사들은 지구내부에서 방사성 동위원소의 붕괴의 설명은 지층의 높은 열과 압력이 그들의 대안개념에 가장 큰 영향을 주고 있었다. 또한 우리가 제안한 과학개념구성을 위한 과학 철학적 수업전략에 따른 그들의 개념변화를 조사하였다.

고장력강이 구조강재로서 널리 사용되고 있다. 구조물의 극심한 하중을 받게되면 최종강도에 도달할 때까지 좌굴을 동반하게 된다. 그러므로, 고장력강판의 좌굴에 대한 정확한 평가가 중요한 설계기준이 되고 있다. 그러나, 고장력강을 효율적으로 사용하기 위해서는 좌굴허용설계를 도입할 수 있도록 판구조물의 판두께가 얇아져야 한다. 따라서, 박판구조물의 합리적인 설계를 하기 위해서는 좌굴후거동해석이 매우 중요하다. 그러므로, 본 논문에서는 호장증분법을 이용하여 압출하중을 받는 박판구조물의 초기좌굴후거동과 2차좌굴강도에 대하여 규명하였다. 특히, 호장증분법을 좌굴정에서의 하중경로를 추정하기 위하여 적용하였다.