• The Korean Journal of Mycology
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• v.43 no.1
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• pp.33-39
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• 2015

In filamentous fungi, velvet complex associated with the veA gene plays pivotal roles in development and secondary metabolism. In a model fungus Aspergillus nidulans, many proteins that can interact with VeA, including two methyltransferases VipB and VipC, have been isolated and characterized. In this study, we isolated homologs of the vipB and vipC genes in the human opportunistic pathogenic fungus Aspergillus fumigatus and named AfuvipB and AfuvipC. The AfuvipB gene, annotated as Afu3g14920 in the Aspergillus Genome Database (AspGD) database, consists of 1,510 bp interrupted with 10 introns yielding 336 amino acid-long putative methyltransferase protein. Similarly, AfuvipC, which is Afu8g01930, has 10 introns and encodes a polypeptide with 339 amino acids having a methyltransferase domain in the middle of the protein. To characterize the function of the genes in A. fumigatus, knock-out mutants were generated and the phenotypes were observed. Deletion of AfuvipB gene caused no obvious phenotypic change on point inoculation but showed smaller colony than wild-type when the mutant was subjected to culture on single spore-driven culture condition. However, AfuvipC deletion mutant demonstrated no phenotypic difference from wild type both in point inoculation and streaking cultures. These results indicate that the two methyltransfereases might have a redundant role and could be dispensable in normal culture conditions.

• Journal of Korean Society of Steel Construction
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• v.30 no.1
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• pp.1-12
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• 2018

A curved member should resist bending and torsional moments simultaneously even though the primary load is usually supposed to be gravitational load. The torsional moment causes complicate stress state and also can result in early yielding of material to reduce member strength. According to analysis results, the strength of a curved member that has 45 degrees of subtended angle could decrease more than 50% compare to straight girder. Nevertheless, there have been very few of researches related with ultimate strength of curved girders. In this study, various kinds of stiffness about bending, pure torsion and warping were considered with a number of models in order to verify the main factor that affects ultimate behavior of curved girder. Lateral and rotational displacement of curved member were introduced as lateral-torsional-vertical behavior and bending-torsional moment interaction curve was derived. Finally, a strength equation for ultimate moment of horizontally curved steel I-girders subjected to equal end moments based on the interaction curves. The equation could take account of the effect of curvature, unbraced length and sectional properties.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8870-8878
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• 2015

During the carbon-dioxide capture and storage(CCS) process, $CO_2$ is captured from large point source, and then injected and stored in stable geological structure for thousands and more years. Inside the captured $CO_2$ flow, various impurities, such as $N_2$, $O_2$, argon, etc, are included inevitably. These impurities affect on the CCS process on various aspects. In this study, we designed and built experimental facility to evaluate the various impurity effect on the $CO_2$ pipeline flow, and analyzed the effect of argon ratio and pressure variation on the pressure drop of $CO_2$ flow. By comparing experimental data with 4 kinds of pressure drop model, we figured out and recommended the Cicchitti's model since it showed most accurate result among compared models in this study.

• The Korea Journal of Herbology
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• v.22 no.2
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• pp.25-33
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• 2007

Objectives : Oriental pear was used as treatment of asthma, control of blood pressure, diabetes in oriental medicine. The aim of this study was to observe the effects of Phenolic compound extracted from pear and herbal drugs to treat asthma. Methods : In order to study the effect of oral administration of phenolic compound extracted from pear and herbal drugs(Platycodon grandiflorum, Prunus armeniaca) on allergic asthma, mice were pre-treated by oral administration of the solution before antigen sensitization four times for 8 days. 2 days later, mice were actively sensitized with a subcutaneous injection of ovalbumin and 13 days later, they were provoked with ovalbumin aerosols. The animals were divided into four groups; Saline, orally administered saline. PC-A, orally administered Phenolic compound extracted from pear peel 10mg/kg/ml. PC-B, orally administered Phenolic compound extracted from pear peel and flesh 10mg/kg/ml. PC-C, orally administered pear 10m/kg/ml, Platycodon grandiflorum 24.4 mg/kg/ml and Prunus armeniaca 33.3 mg/kg/ml. Serum level of IgE, IL-4, cell numbers in the bronchoalveolar lavage fluid(BALF), and in vitro isometric contractile responses of the isolated tracheal smooth muscle(TSM) to acetylcholine(ACh, $0.1-1000{\mu}M$), KCl were measured. Results : Contractile responses of TSM to ACh were decreased in PC-A group at Ach 0.1, 0.3, 1 ${\mu}M$, decreased in PC-B at 0.1 ${\mu}M$ and decreased in PC-C at 0.1, 0.3, 1, 10, 30 ${\mu}M$. The maximal contractile response of TSM to KCl was decreased in PC-C group, The cell numbers of eosinophil in BALF were decreased in PC-C group, and those of macrophages in BALF were decreased in PC-A and PC-C group. Interleukin-4 in BALF was decreased in PC-A, PC-B, PC-C group. Conclusion : Based on the above results it is assumed that oral administration of phenolic compound extracted from pear and herbal drugs can help the treatment of deficiency allergic Asthma.

• Journal of Korea Spatial Information System Society
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• v.1 no.2 s.2
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• pp.99-113
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• 1999

The role of a GIS as a tool for a national information infrastructure can best be fulfilled once GIS standards are implemented. In this paper, we have identified what the contents of GIS standards in other countries are, and what should be the future direction for implementing a nation's GIS standards. Based on a detailed review on GIS standards in the USA, Australia, Japan and the United Kingdom, we derived the following: (1) A nations's GIS standards should include both geographic information content standards and geographic information service standards: (2) A nation's GIS standards should be a profile of ISO GIS standards: (3) Each GIS standards should be developed on the bassis of the Entity-Relationship Model using Unified Modeling Language: and (4) Experts in GIS should pay much more attention on studies on GIS service standardization. As for building the national GIS Standards for Korea, we recommend both GIS Content Standards and GIS Service Standards be simultaneously developed. GIS Content Standards include geographic feature content standard, feature classification standard, portrayal standard, rules for application standards, spatial reference model and terminology. GIS Service Standards include standards for data sharing such as metadata standard and transfer standard, quality standard, quality principle and portrayal standards.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.5 s.96
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• pp.482-487
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• 2005

In this paper, we propose the control method of output impedance of each cascode unit cell of distributed amplifier by connecting varactors in the gate-terminal of common gate. Compared to common source unit cell, cascode unit cell has many advantages such as high gain and high output impedance as well as negative resistance loading. But if the transistor model which is used in design is inaccurate and process parameter is changed, oscillation sometimes can occur at band edge in which the gain start to drop. Therefore, we need control circuit which can prevent oscillation, although the circuit has already fabricated, and varactor connected to gate-terminal of common gate of cascode gain cell can play that part. Measured result of fabricated distributed amplifier shows the capability of contol of gain characteristic by adjusting of value of varactors, this can guarantee the stability of the circuit. The gain is $8.92\pm0.82dB$ over 49 GHz, the group delay is $\pm9.3 psec$ over 41 GHz. All transistor which has $0.15{\mu}m$ gate length is GaAs based p-HEMT, and distributed amplifier is put together with 4 stages.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.5
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• pp.511-520
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• 2007

There is a concern with worldwide deterioration of highway bridges, particularly reinforced concrete. The advantages of fibre reinforced plastic(FRP) composites over conventional materials motivate their use in highway bridges for replacement of structures. Recently, an FRP deck has been installed on a state highway, located in New York State, as an experimental project. In this paper, a systematic approach for analysis of this FRP deck bridge is presented. Multi-step linear numerical analyses have been performed using the finite element method to study the structural behavior and the possible failure mechanism of the FRP deck-superstructure system. Deck's self-weight and ply orientations at the interface between steel girders and FRP deck are considered in this study. From this research, the results of the numerical analyses were corroborated with field test results. Analytical results reveal several potential failure mechanism for the FRP deck and truss bridge system. The results presented in this study may be used to propose engineering design guideline for new and replacement FRP bridge deck structure.

• Journal of the Korean GEO-environmental Society
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• v.15 no.12
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• pp.109-115
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• 2014

The purpose of this study is to estimate the sediment volume concentration of the liquified-solid mixture which is included fine sediment fractions, according to the variance of the channel slope and the water supply. The numerical model was performed by using the Finite Differential Element Method (FDM) based on the equation for the mass conservation, momentum conservation and the equation of coarse sediment an fine sediment. In comparison of varying the channel slope, the deeper the channel slope, the inflection point of the sediment concentration was occurred rapidly. In comparison of variance of the water supply, as the water supply increases fluctuation with high sediment concentration. In this situation, debris flow changes to the turbulent flow and the sediment becomes to be floated. In comparison varying the length paved saturated sediment, the longer the length, the high concentration of sediment occurred, for the safety of the slope it is needed to check the possibility of the erosion in the slope by debris flow. The results of this study will provide useful information in predicting of the disaster by the liquified-solid mixture and in prevention of the debris flow with various the slope in the mountain side.

• The korean journal of orthodontics
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• v.39 no.4
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• pp.203-212
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• 2009

Objective: The aim of this study was to evaluate the strain induced in the cortical bone surrounding an orthodontic microimplant during insertion in a self-drilling manner. Methods: A 3D finite element method was used to simulate the insertion of a microimplant (AbsoAnchor SH1312-7, Dentos Co., Daegu, Korea) into 1 mm thick cortical bone. The shape and dimension of thread groove in the center of the cortical bone produced by the cutting flute at the apical of the microimplant was obtained from animal test using rabbit tibias. A total of 3,600 analysis steps was used to calculate the 10 turns and 5 mm advancement of the microimplant. A series of remesh in the cortical bone was allowed to accommodate the change in the geometry accompanied by the implant insertion. Results: Bone strains of well higher than 4,000 microstrain, the reported upper limit for normal bone remodeling, were observed in the peri-implant bone along the whole length of the microimplant. Level of strains in the vicinity of either the screw tip or the valley part were similar. Conclusions: Bone strains from a microimplant insertion in a self-drilling manner might have a negative impact on the physiological remodeling of cortical bone.

• Korean Journal of Social Welfare
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• v.58 no.4
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• pp.341-369
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• 2006

This study attempts to explain how the social-worker empowerment in the field of social work relates to social-work self-efficacy and whether or not the transactional leadership of the leader moderates the relationship between these two variables. Data from 390 social workers working with public and private sector agencies in Seoul were collected. For the questionnaire and analysis, this research uses the Social Worker Empowerment, Social Work Self-Efficacy, and Transactional Leadership scales. This research utilizes a wide range of statistical analyses, such as descriptive analysis, Pearson's correlation, reliability analysis, factor analysis, multiple regression, and general linear modeling. The calculations employed the use of SPSS/PC+ 12.0. This research indicates, among other things, that social workers with a high level of social worker empowerment and transactional leadership of the leader show a tendency toward higher social work self-efficacy and that the leader's transactional leadership level plays a moderating function in the relationship between social-worker empowerment and transactional leadership of the leader. In conclusion, a social worker with a low level of leader's transactional leadership shows a relatively greater tendency toward social work self-efficacy when compared to a social worker having a high level of leader's transactional leadership. Social workers and social-work organizations seeking professional practice can benefit from these findings on the relationship between professional behavior and social work self-efficacy with perceived transactional leadership about a team leader as a moderator.