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        검색결과 59

        41.
        2023.03 KCI 등재 서비스 종료(열람 제한)
        This study aimed to improve the level of satisfaction and service quality of a forest experience education program for vulnerable social groups by administering a survey problems of the program and suggested improvements. 428 participants in the program. Reliability analysis of the survey yielded values of, Cronbach’s α value was higher than 0.8 for all items, indicating very high reliability. Importance-performance analysis (IPA), a method of measuring and comparing the degree of satisfaction, found two factors: “first need for correction” which included “diversity of programs” and “professionalism of programs”; and “the need for sustained effort” which included “benefits of programs”, “the role of program instructors” and “the interest of programs”. Previously, forest experience education focused on programs involving base expansion and promotion, or quantitative expansion education. Therefore, this study is meaningful in providing basic data on forest experience education for vulnerable social groups.
        42.
        2022.09 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to provide basic data for logical forest management by developing a site index curve reflecting the current growth characteristics of Cryptomeria japonica stands in Korea. The height growth model was developed using the Chapman-Richards, Schumacher, Gompertz, and Weibull algebraic difference equations, which are widely used in growth estimation, for data collected from 119 plots through the 7th National Forest Inventory and stand survey. The Chapman-Richards equation, with the highest model fit, was selected as the best equation for the height growth model, and a site index curve was developed using the guide curve method. To compare the developed site index curve with that on the yield table, paired T-tests with a significance level of 5% were performed. The results indicated that there were no significant differences between the site index curve values at all ages, and the p-value was smaller after the reference age than before. Therefore, the site index curve developed through this study reflects the characteristics of the changing growth environment of C. japonica stands and can be used in accordance with the site index curve on the current yield table. Thus, this information can be considered valuable as basic data for reasonable forest management.
        43.
        2022.06 KCI 등재 서비스 종료(열람 제한)
        This study was to evaluate the utilization of terrestrial light detection and ranging for forest inventory in coniferous forests. Heights and diameter of the stand trees were measured manually using the traditional measurement method and the method using terrestrial LiDAR. The results of two methods were compared and analyzed to evaluate accuracy and feasibility. The terrestrial LiDAR used fixed and handy types to compare the accuracy between different operational methods. Comparative analyses used a paired t-test and Bland-Altman plot analysis. In the case of tree heights, the average of difference between the traditional method and terrestrial LiDAR for each plot was 0.81 m, -0.07 m, and 0.13 m for fixed type; 2.88 m, 1.19 m, and 0.93 m for the handy type. In the case of tree diameter at breast height, the average value of the difference between traditional methods and terrestrial LiDAR for each plot was 0.13 cm, -0.66 cm, and –0.03 cm for fixed type; 2.36 cm, 2.13 cm, and 1.92 cm for the handy type. The values from the method using the fixed type was highly consistent with that using the traditional measurement methods; the average difference was closer to zero. The crown density influences the precision of the height measurement using terrestrial LiDAR in coniferous forests. Therefore, future studies should focus on verifying the a
        44.
        2019.05 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 노후화된 공동주택 수직 증축 리모델링 시 면진시스템의 적용성을 검토 및 면진시스템 적용을 위한 기초자료를 제공할 목적으로 동일한 구조로 수직 증축 시 수직 층수와 면진주기에 따른 최적 면진주기를 산정하였다. 해석결과, 3개층 수직 증축 시에는 면진주기를 비면진 건물 주기의 2배 이상, 2개층 수직 증축 시에는 비면진 건물 주기의 3배 이상을 확보하여야만 충분한 면진효과를 나타내는 것을 알 수 있었다. 또한, 1개층 수직 증축 시에는 비면진 건물 주기의 4배 이상을 확보하여야만 면진효과를 나타내었다. 위의 결과를 활용하여 3개층 수직증축 리모델링 대상 공동주택에 면진시스템을 적용하여 그 효과를 검증하였다. 최상층 최대응답가속도가 비면진 건물의 최대응답가속도 보다 X방향의 경우에는 약 70%로, Y방향의 경우에는 약 65%의 감소를 나타내었다. 또한, 밑면 전단력의 경우, 비면진 건물과 비교하여 X방향 및 Y방향 모두 약 30% 감소하는 것으로 나타났다.
        45.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        최근 들어 우리나라에서도 설치와 유지관리가 용이하며 경제성이 뛰어난 강재이력형 감쇠장치를 적용하여 내진성능을 확 보하고자 하는 건물들이 다수 건설되고 있다. 하지만 이러한 강재이력형 감쇠장치가 철근콘크리트 건물에 적용되는 경우 감쇠장치를 설치하기 위한 연결구조물은 전체적인 시스템을 복잡하게 만들어 감쇠장치의 신뢰도를 저하시키는 요소가 되기도 한다. 이에 본 연구 에서는 기존연구에서 개발된 카고메 감쇠장치를 대상으로 별도의 연결구조 없이 철근콘크리트 지지구조물에 감쇠장치를 직접 매립할 수 있는 시스템을 제안하고자 하며, 매립길이에 따른 내진거동을 확인하여 동 시스템의 정립을 위한 기초자료를 제공하고자 한다. 실험 결과, 1.0ld 매립길이 실험체의 경우 카고메 감쇠장치 매립부분에서 콘 파괴와 유사한 형태의 뽑힘이 발생하였다. 반면, 2.0ld 매립길이를 확보 한 실험체는 실험 종료 시까지 뽑힘 및 콘 파괴 없이 안정적인 이력거동을 나타내었고 1.0ld 매립길이 대비 2.0ld 매립길이가 약 1.3배의 향상된 에너지소산능력을 나타내었다. 본 연구에서 제안하는 시스템을 적용할 경우, 기존 설치방법 변경에 따른 기타 철물 제작 비용을 줄일 수 있으 며, 시공 시에도 부수적인 철물 시공을 줄여 공기를 단축할 수 있다.
        46.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        최근 들어 건물의 내진 및 내풍 성능을 향상시키기 위하여 감쇠구조에 대한 관심이 높아지고 있다. 감쇠장치 중 저렴한 비용과 높은 에너지소산능력을 발휘하며, 설치와 유지관리가 용이하다는 장점이 있어 강재이력형 감쇠장치를 이용한 수동형 감쇠구조시스템이 널리 사용 되고 있다. 본 논문에서는 라멘구조 또는 무량판 구조에 적합한 계단 설치형 카고메 감쇠시스템(SKDS)을 제안하고자 하며, 제안된 감쇠시스템의 지진응답 개선효과에 대하여 해석적으로 검토하고자 한다. 비선형 동적해석결과 최대응답변위, 최대응답가속도 및 밑면전단력 감소로 살펴볼 때 내진구조와 비교하여 더 향상된 거동이 기대된다는 점에서 SKDS의 효과를 확인할 수 있었다.
        47.
        2017.08 서비스 종료(열람 제한)
        This study analyzed the mitochondrial DNA (mtDNA) sequences of the Red-spotted grouper, Epinephelus akaara (Perciformes, Serranidae), and used for construction of molecular phylogeny and for association between maternal haplotypes and phenotypic differences of F1 progeny. This study revealed phylogenetic position of the endangered red-spotted grouper, Epinephelus akaara (Perciformes, Serranidae) based on the nucleotide sequences of complete mt genome. Complete nucleotide sequences were determined from the mt genomes of two individuals of the red-spotted grouper caught in South Korea. The mitochondrial genome had 16,795 base pairs (bp) and 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a noncoding control region. The two mt genomes were highly homologous (99.71% similarity). The two mt genomes of E. akaara determined in this study were found in Clade I in the phylogenetic tree with those of E. awoara, E. fasciatomaculosus, E. sexfasciatus, E. diacanthus, E. sticus, and E. morio, suggesting that this may be helpful to understand phylogenetic position of Epinephelus species including red-spotted grouper. The genetic structure and phylogenetic relationship were investigated in the red-spotted grouper populations using the sequence polymorphisms of the cytochrome c oxidase subunit I(COI) gene and variable number of tandem repeats (VNTRs) of the control region (CR). A total of forty-one COIhaplotypes were found from 174 COIsequences from East Asia. The Jeju Island population (n=5) had four haplotypes, and the South Sea population (n=105) had twenty-five haplotypes. The Hong Kong population had nineteen haplotypes from fifty-nine COIsequences determined in this study. Among the COIhaplotypes, EAC_03 is commonly found in all populations (Jeju Island and South Sea of Korea, China, Hong Kong and Taiwan). In addition, there were four haplotypes (EAC_12, EAC_14, EAC_28 and EAC_35) also common among the populations tested in this study and collected from NCBI database. However, twenty haplotypes were specific in the Korean populations, and fifteen haplotypes were specific in the China and Hong Kong populations. The neighbor-joining (NJ) trees constructed from the phylogenetic analyses based on the polymorphisms of the COIhaplotypes showed the monophyletic branching pattern within the genus Epinephelus, indicating that the red spotted grouper populations had evolved from common maternal ancestors. Consequently, East Asian red-spotted grouper populations are maternally related at least in part, as well as sharing the same evolutionary history, and still affected by the East Asian ocean current (Kuroshio). From the haplotype analysis for mtDNA CR, we obtained VNTR polymor-phisms in all populations tested. We found five haplotypes for the CR VNTR patterns. The 133-bp repeat units were counted two to five. Using CR VNTR haplotypes, the statistical association was examined between mtDNA haplotypes and growth traits of aquafarming young fishes of the red-spotted grouper. A total of 386 F1 progeny, which were randomly selected from a progeny population produced by artificial insemination in the farm, were genotyped and statistically compared their body length (BL), body weights (BW) and length-weight indexes (LWI) at 11-months after hatching. There haplotypes H03, H04 and H05 were detected for CR in the parents and progeny populations. The significant difference was found in the BL values among three haplotypes (p<0.05). The F1 animals with haplotype H03 had freater level of BL (19.22±2.000 cm) than those of H04 (18.64±1.964 cm) and H05 (18.86±1.512 cm). There were no significant differences in BW and LWI among haplotypes (p<0.05). These results concluded that the maternal lineages affected the growth rates during early developmental stage in the red-spotted grouper. These findings suggested that the mitochondrial background of the fertilized eggs may play an important role in the early development, and the markerassisted selection system for broodstork animals may be helpful in improving performance traits for aquaculture industry as well as for conservation biology of the endangered red-spotted grouper. However, the results from the association analysis between haplotypes and phenotypes of F1 progeny (n=1,093) at 60-days after hatching showed that there were no significant difference (p>0.05). Consequently, the results of this study may be useful information for understanding the evolutionary relation with other species and may be good genetic markers for breeding management in the red-spotted grouper aquaculture system.
        48.
        2016.05 KCI 등재 서비스 종료(열람 제한)
        이 논문은 지진응답을 감소시키기 위해 외부설치형 카고메 감쇠시스템의 유효성을 비선형 동적 해석 결과를 통해 나타내었다. 이 전의 연구에 의해 제안된 카고메 감쇠시스템을 활용하여 본 연구에서는 등방성, 이선형 이력특성 및 설치구성이 새롭게 제안하였다. 또한, 외부접합형 카고메 감쇠시스템의 여러 가지 효과를 15층 및 20층 철근콘크리트 라멘조 아파트를 대상으로 검증하였다. 원구조물에 대한 감쇠장 치 지지구조물의 강성비, 감쇠장치의 수량 및 설치 층수는 설계변수로 고려하였다. 수치해석결과, EKDS는 기존의 한 방향 층간에 설치되는 감 쇠시스템과 비교할 때 더 작은 수를 적용하여도 두 방향의 지진하중을 감소시키는데 매우 효과적임을 입증되었다.
        49.
        2015.09 KCI 등재 서비스 종료(열람 제한)
        본 논문에서는 효과적인 제진설계를 구현하기 위한 설계기술 개발의 일환으로 최근 제안된 Exo-type 감쇠시스템을 활용하여 15층과 20층의 연구 대상 건물을 대상으로 감쇠시스템의 최적 강성비와 적용된 감쇠장치의 최적 항복비에 따른 철근콘크리트 라멘조 건물의 제진 효과를 검토해 보았다. 해석결과, Exo-type 감쇠시스템을 3개층 적용 시에는 대상 건물 15층과 20층 모두 밑면전단력과 최상층 최대응답변위 감소라는 관점에서 유효한 제진효과를 얻기 위해서는 Exo-type 감쇠시스템과 대상 건물의 강성비는 7.0 이상 확보를 하여야 하며, 감쇠시스템에 적용된 감쇠장치의 항복비는 대상 건물의 층전단력의 약 8.0% 이상 확보할 필요가 있는 것으로 나타났다. 또한, Exo-type 감쇠시스템을 5개층 적용 시에는 대상 건물 15층과 20층 모두 Exo-type 감쇠시스템과 대상 건물의 강성비는 2.5 이상 확보 하여야 하며, 감쇠시스템에 적용된 감쇠장치의 대상 건물의 층전단력의 약 3.5%이상 확보할 필요가 있는 것으로 나타났다.
        50.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        In this paper, the vibration control effect of the isotropic damping devices (so-called Kagome dampers) was investigated by applying the Kagome dampers to a 20-story frame structure apartment. A new Kagome Damper System (KGDS) composed of the dampers and supporting column was proposed and numerical analyses were performed to investigate the effects of stiffness ratio between controlled structure and supporting column, the damper size and the number of the dampers. The numerical analysis results of a structure with KGDS up to the third story showed that the stiffness ratio should be higher than 6.4 and the damper size be at least 700×700mm to effectively reduce the base shear and the maximum drift of the uppermost story. When the KGDS was installed up to the fifth story, the stiffness ratio should be higher than 7.0 and damper size needs to be at least 500×500mm for obtaining the target performance
        54.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        Phytochemical investigation of the sesame dregs of Sesamum indicum was conducted by open column and prep-HPLC chromatography. Two phytosterols (1 and 2) and two lignans (3 and 4) were isolated from the MeOH extracts of sesame dregs, and identified as β-sitosterol (1), daucosterol (2), sesamin (3), and sesamolin (4) by spectral analysis. Although these compounds were already isolated from sesame, it is important that they were still main phytochemical components in the sesame dregs.
        55.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        High performance liquid chromatography (HPLC) was used for the analysis of chiisanoside in each stem and root of Acanthopanax senticosus collected from South Korea, North Korea, China and Russia. A reverse-phase system using a gradient of H2O and acetonitrile as the mobile phase was developed and detection was at 210nm. The analysis was successfully carried out within 30 min. Chiisanoside was measured in the stem and root of A. senticosus collected from various countries.
        56.
        2006.10 KCI 등재 서비스 종료(열람 제한)
        High performance liquid chromatography (HPLC) was used for the determination of lignans, eleutherosides B and E, in Acanthopanax sessiliflorus fruits and their fermented wine. The lignans were quantified by a reversed-phase system using a gradient of H2O and acetonitrile as a mobile phase within 20 min. The analysis was successfully carried out within 20 min. The contents of eleutherosides Band E as main active principles of Acanthopanax species were measured in A. sessiliflorus fruits (1.15 and 8.49 μg/mg, respectively), their fermented wine (0.45 and 1.33 μg/mg, respectively) and wine residues (no detection).
        57.
        2003.11 KCI 등재 서비스 종료(열람 제한)
        Five constituents were isolated from the stem of Acanthopanax senticosus. Their structures were elucidated as (-)-sesamin (1), iso-fraxidin (2), 5-hydroxymethylfurfural (3), syringin (4) and acanthoside D (5) by spectral analysis. Among these compounds, 5-hydroxymethylfurfural (3) was isolated for the first time from this plant.
        58.
        2003.11 KCI 등재 서비스 종료(열람 제한)
        Five lignans were isolated from the chloroform fraction of Acanthopanax chiisanensis Nakai root by open column chromatography. Their structures were elucidated as (-)-sesamin (1), helioxanthin (2), savinin (3), taiwanin C (4), and 3-(3",4"-dimethoxybenzyl)-2-(3',4'-methylenedioxybenzyl) butyrolactone (5) by spectral analysis. Among them, compounds 2, 3, 4, and 5 were isolated for the first time from this plant.
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