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        검색결과 122

        67.
        2018.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this study, we evaluated the antioxidant activity and anti-inflammatory effects of Abeliophyllum distichum (A. distichum) leaves that were prepared via air-drying. Fresh and air-dried A. distichum leaves were examined via 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assay and measurements of the reducing power. The suppression effects on inflammation of the leaves were analyzed by a western blot and RT-PCR on LPS-induced RAW 264.7 cells. As a result, the antioxidant activity of the fresh leaves was found to be more effective than that of the air-dried leaves. Also, the fresh leaves were more effective in suppressing the protein and mRNA levels of iNOS and COX-2 than the air-dried leaves, thereby indicating the better anti-inflammatory effects. In addition, the contents of phenolic compounds and acteoside were analyzed by high-performance liquid chromatography (HPLC). The results showed that the acteoside content decreased with the use of the air-drying method, while there was no change in the content of phenolic compounds. Therefore, this study indicated that fresh A. distichum leaves potential antioxidant and suppression activities of various factors that are involved in the production of NO, which were found to be better than those of air-dried A. distichum leaves. These biological activities were also found to be independent of the content of phonolic compounds and were assumed to be directly or indirectly related to the content of acteoside.
        68.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        In the shipping industry, it is well known that around 80 % or more of all marine accidents are caused fully or at least in part by human error. In this regard, the International Maritime Organization (IMO) stated that the study of human factors would be important for improving maritime safety. Consequently, the IMO adopted the Casualty Investigation Code, including guidelines to assist investigators in the implementation of the Code, to prevent similar accidents occurring again in the future. In this paper, a process of the human factors investigation is proposed to provide investigators with a guide for determining the occurrence sequence of marine accidents, to identify and classify human error-inducing underlying factors, and to develop safety actions that can manage the risk of marine accidents. Also, an application of these investigation procedures to a collision accident is provided as a case study This is done to verify the applicability of the proposed human factors investigation procedures. The proposed human factors investigation process provides a systematic approach and consists of 3 steps: ‘Step 1: collect data & determine occurrence sequence’ using the SHEL model and the cognitive process model; ‘Step 2: identify and classify underlying human factors’ using the Maritime-Human Factor Analysis and Classification System (M-HFACS) model; and ‘Step 3: develop safety actions,’ using the causal chains. The case study shows that the proposed human factors investigation process is capable of identifying the underlying factors and indeveloping safety actions to prevent similar accidents from occurring.
        69.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        최근 우리나라 연근해에서 발생한 몇 건의 대형 해양사고에서, 신속하고 체계적인 초기대응이 사고 전개양상과 사고결과에 얼마나 큰 영향을 미치는지를 확인하였다. 또한, 이를 통해 다양한 해양사고 상황에 대한 정확한 정보와 전개될 수 있는 시나리오, 적용 가능한 사고 대응 방법들에 대한 정보를 신속하게 확보하는 것이 해양사고 초기대응을 위하여 무엇보다 중요함을 알 수 있었다. 이러한 현실적인 문제를 해결하기 위한 일환으로, 본 연구에서는, ‘위험도기반 초기대응 지원 시스템’의 개념을 제시하고, 해양사고 이후 전개 가능한 모든 시나리오와 적용 가능한 사고대응 방법들을 식별하기 위하여 사건전개 시나리오 식별 브레인스토밍 기법을 제안하였으며, 식별된 사고대응 방법들의 적 용으로 인한 피해저감 효과 등을 정량화하기 위하여 사건수목분석 (Event Tree Analysis: ETA) 기법을 활용한 사건전개수목을 제안하였다. 그리고 각각의 사고대응 방법에 대한 상세분석을 위해서는 PERT/CPM의 사용을 제안하였다. 또한, 상기 제시한 위험도기반 초기대응 지원 시스템의 구성 체계를 설명하기 위하여, 유조선 좌초사고에 대한 사고대응 작업을 예로 간략한 위험도분석 작업을 수행하였다.
        70.
        2016.05 서비스 종료(열람 제한)
        Background : Osteoclasts as multinucleated cells originate from hematopoietic monocyte/ macrophage precursor cell, shows the bone absorption through the commitment, differentiation, fusion, and bone resorption stages by regulation of M-CSF and RANKL. It has been reported a significant negative correlation between the increase of oxidative stress and the bone density, and when RANKL reaction to the osteoclasts precursor cells is mainly generated ROS is due to increased activity of NADPH oxidase1 (NOX1), and these ROS act as a factor which promotes osteoclasts differentiation. Thus, RANKL signaling process is important that excessive osteoclast formation and differentiation inhibited through the regulation of each step. Methods and Results : F3570 ethanol extract showed relatively high activity at in-vitro antioxidant activity. F3570 water extract inhibited ROS generation in RAW 264.7 cells stimulated with H2O2 and RANKL, even at low concentrations. The inhibitory effect of osteoclast differentiation on F3570 water extract was confirmed that shown through NF-κB pathway, MAPK pathway including ERK and JNK. F3570 ethanol extract is considered to be regulated by the p38 MAPK and the other signaling pathway. Also, F3570 both water and ethanol extract were significantly reduced gene expression such as TRAP, calcitonin receptors and integrin β3 of RANKL-induced mature osteoclast in the bone resorption stage. Conclusion : Through this study, F3570 extract revealed an outstanding inhibitory effect and signaling mechanisms in osteoclast differentiation induced by RANKL. These results suggest that F3570 is bone diseases associated with aging or osteoporosis caused by menopause in an aging society is expected to be a superior candidate for the treatment or the prevention
        71.
        2013.07 서비스 종료(열람 제한)
        Inactivation of the gene (DFR-A) coding for dihydroflavonol 4-reductase (DFR) involved in the anthocyanin biosynthesis pathway results in a yellow bulb color in onion (Allium cepa L.) and three inactive alleles have previously been identified in onion. Additionally, three active and six inactive DFR-A alleles were newly identified from extensive analyses of diverse onion germplasm. Presently, a yellow mutant containing a 171-bp deletion in the promoter region was identified and designated DFR-APD. Critically reduced transcription of this mutant allele and perfect co-segregation with color phenotypes in segregating populations were observed. Another yellow mutant (DFR-A5’DEL) containing a 518-bp deletion covering exons 1 and 2, which played important roles in DFR function, was identified. Meanwhile, both 2-bp and 4-bp insertions in the coding region leading to creation of pre-mature stop codons were also identified and designated DFR-AGT and DFR-A2AT, respectively. A 1-bp substitution mutation (DFR-AK48N) changing a positively charged lysine residue into a neutral asparagine was identified. This lysine residue, a NADPH binding site, was strictly conserved in other species. In addition, insertion of a leucine residue around substrate binding sites and catalytic triad was identified in several yellow accessions and was designated DFR-ATTA. Phylogenetic analysis of DFR-A alleles showed that all inactive alleles were independently derived from four different active alleles. In addition, the close relatedness and diversity of DFR-A mutants implied that all these mutations might have occurred after domestication of onions and had probably been maintained by artificial selection.
        78.
        2011.02 서비스 종료(열람 제한)
        Since cable members are the major structural components in cable bridges, they should be properly inspected for surface damage as well as inside defects such as corrosion and/or breakage of wires. Starting from August 2010, a new research project supported by Korea Ministry of Land, Transportation Maritime Affairs (MLTM) was initiated to develop the cable inspection robot. In this study, only the vision-based surface damage detection system based on image processing techniques is addressed. The damage detection algorithm combines some image enhancement techniques with principal component analysis (PCA) to detect damages on cable surface. The images from three cameras attached to the cable climbing robot are wirelessly transmitted to the server computer at the cable support. They are processed with image enhancement method together with noise removal technique to improve overall image quality. Then they are projected into PCA sub-space. Finally, the Mahalanobis square distances of the projected images to all sample patterns are calculated. The smallest distance is found to be the match for the input image. The proposed damage detection algorithm was verified through laboratory tests on three types of cables.
        80.
        2010.03 KCI 등재 서비스 종료(열람 제한)
        The management of safety at sea is based on a set of internationally accepted regulations and codes, governing or guiding the design and operation of ships. The regulations most directly concerned with human safety and protection of the environment are, in general, agreed internationally through the International Maritime Organization(IMO). IMO has continuously dealt with safety problems and, recognized that the human element is a key factor in both safety and pollution prevention issues(IMO, 2010). This paper proposes a human error analysis methodology which is based on the human error taxonomy and theories (SHELL model, GEMS model and etc.) that were discussed in the IMO guidelines for the investigation of human factors in marine casualties and incidents. In this paper, a cognitive process model, a human error analysis technique and a marine accident causal chains focused on human factors are discussed, and towing vessel collision accidents are analyzed as a case study in order to examine the applicability of the human error analysis technique to marine accidents. Also human errors related to those towing vessel collision accidents and their underlying factors are discussed in detail.
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