• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.19 no.4 s.74
• /
• pp.429-440
• /
• 2006

This paper comprises two specific objectives. The first is to examine the applicability of ordinary kriging interpolation(OK) to the p-adaptivity of the finite element method that is based on variogram modeling. The second objective Is to present the adaptive procedure by the hierarchical p-refinement in conjunction with a posteriori error estimator using the modified S.P.R. (superconvergent patch recovery) method. The ordinary kriging method that is one of weighted interpolation techniques is applied to obtain the estimated exact solution from the stress data at the Gauss points. The weight factor is determined by experimental and theoretical variograms for interpolation of stress data apart from the conventional interpolation methods that use an equal weight factor. In the p-refinement, the analytical domain has to be refined automatically to obtain an acceptable level of accuracy by increasing the p-level non-uniformly or selectively. To verify the performance of the modified S.P.R. method, the new error estimator based on limit value has been proposed. The validity of the proposed approach has been tested with the help of some benchmark problems of linear elastic fracture mechanics such as a centrally cracked panel, a single edged crack, and a double edged crack.

• Proceedings of the Botanical Society of Korea Conference
• /
• 2002.04a
• /
• pp.62-72
• /
• 2002

This study has investigated the biosynthesis and function of the heavy metal binding peptides, the phytochelatins, in plants. PCs are synthesised enzymatically from glutathione by the enzyme PC synthase in the presence of heavy metal ions. Using Arabidopsis thaliana as a model organism cadmium-sensitive, phytochelatin-deficient mutants have been isolated and characterised in previous studies. The cadl mutants have wildtype levels of glutathione, are PC deficient and lack PC synthase activity. Thus, the CADl gene has been proposed to encode PC synthase. The CADl gene was isolated by a positional cloning strategy The gene was mapped and a candidate identified. Each of four cadl mutants had a single base pair change in the candidate gene and the cadmium-sensitive, cadl phenotype was complemented by the candidate gene. This demonstrated the CADl gene had been cloned. A homologous gene in the fission yeast, Schizosaccharomyces pombe was identified through database searches. A targeted-deletion mutation of this gene was constructed and the mutant, like cadl mutants of Arabidopsis, was cadmium-sensitive and PC-deficient. A comparison of the redicted amino acid sequences reveals a highly conserved N-terminal region Presumed to be the catalytic domain and a variable C-terminal region containing multiple Cys residues proposed to be involved in activation of the enzyme by metal ions. Similar genes were also identified in animal species. The Arabidopsis CADl/AtPCSl and S. pombe SpbPCS genes were expressed in E. coli and were shown to be sufficient for glutathione-dependent, heavy metal activate PC synthesis in vitro, thus demonstrating these genes encode PC synthase enzymes. Using RT-PCR, AtPCSl expression appeared to be independent of Cd exposure. However, at higher levels of Cd exposure a AtPCSl-CUS reporter gene construct appeared to be more highly expressed. Using the reporter gene construct, AtPCSl was expressed most tissues. Expression appeared to be greater in younger tissues and same higher levels of expression was observed in some regions, including carpels and the base of siliques. AtPCS2 was a functional gene encoding an active PC synthase. However, its Pattern of expression and the phenotype of a mutant (or antisense line) have not been determined. Assuming the gene is functional then it has clearly been maintained through evolution and must provide some selective advantage. This implies that, at least in some cells or tissue, it is likely to be the dominant PC synthase expressed. This remains to be determined

• Journal of the Korean Magnetics Society
• /
• v.10 no.5
• /
• pp.225-231
• /
• 2000

The crystallographic and magnetic properties of the sample F $e_{0.8}$ $Co_{0.18}$(BN)$_{0.02}$ synthesized by microwave arc-melting with the maximum power of 3.5 kW have been studied by the methods of an X-ray diffraction and the measurement of the magnetic hysteresis using the vibrating sample magnetometer at room temperature. The samples were prepared in a form of pellet pressed under the pressure of 9,000 N/c $m^2$, rolled coldly, and treated with the different temperatures. The X-ray diffraction pattern of pelleted sample shows that the crystal structure of the sample is bcc as same as that of Fe with a good uniformity. The X-ray diffraction pattern shows that a residual stress, which exists in the sample, is eliminated by final 90$0^{\circ}C$ annealing. As rolling rate and heat treatment temperature increases, the saturation magnetization and the remanence of the samples increase whereas the coercivity of the samples shows decrease. Also the saturation magnetization and the remanence of the samples were affected by rolling rate and rolling direction than heat treatment temperature, but the coercivity of the samples was affected by rolling rate and direction as well as heat treatment temperature. This means that a domain wall motion is easy due to elimination of a residual stress and an inclusion which exists in the sample by rolling and heat treatment and a local induced-magnetization easy axis was also formed to parallel to the rolling direction due to creation of the like-atom pairs across the slip plane by rolling......

• Journal of Microbiology and Biotechnology
• /
• v.24 no.7
• /
• pp.943-953
• /
• 2014

The XylH gene (1,167-bp) encoding a novel hemicellulase (41,584 Da) was identified from the genome of Microbacterium trichothecenolyticum HY-17, a gastrointestinal bacterium of Gryllotalpa orientalis. The enzyme consisted of a single catalytic domain, which is 74% identical to that of an endo-${\beta}$-1,4-xylanase (GH10) from Isoptericola variabilis 225. Unlike other endo-${\beta}$-1,4-xylanases from invertebrate-symbiotic bacteria, rXylH was an alkali-tolerant multifunctional enzyme possessing endo-${\beta}$-1,4-xylanase activity together with ${\beta}$-1,3/${\beta}$-1,4-glucanase activity, which exhibited its highest xylanolytic activity at pH 9.0 and 60oC, and was relatively stable within a broad pH range of 5.0-10.0. The susceptibilities of different xylosebased polysaccharides to the XylH were assessed to be as follows: oat spelts xylan > beechwood xylan > birchwood xylan > wheat arabinoxylan. rXylH was also able to readily cleave p-nitrophenyl (pNP) cellobioside and pNP-xylopyranoside, but did not hydrolyze other pNP-sugar derivatives, xylobiose, or hexose-based materials. Enzymatic hydrolysis of birchwood xylan resulted in the product composition of xylobiose (71.2%) and xylotriose (28.8%) as end products.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.2
• /
• pp.321-334
• /
• 2017

Process surveillance within agricultural biogas plants (BGPs) was concurrently studied by high-throughput 16S rRNA gene amplicon sequencing and an optimized quantitative microscopic fingerprinting (QMF) technique. In contrast to 16S rRNA gene amplicons, digitalized microscopy is a rapid and cost-effective method that facilitates enumeration and morphological differentiation of the most significant groups of methanogens regarding their shape and characteristic autofluorescent factor 420. Moreover, the fluorescence signal mirrors cell vitality. In this study, four different BGPs were investigated. The results indicated stable process performance in the mesophilic BGPs and in the thermophilic reactor. Bacterial subcommunity characterization revealed significant differences between the four BGPs. Most remarkably, the genera Defluviitoga and Halocella dominated the thermophilic bacterial subcommunity, whereas members of another taxon, Syntrophaceticus, were found to be abundant in the mesophilic BGP. The domain Archaea was dominated by the genus Methanoculleus in all four BGPs, followed by Methanosaeta in BGP1 and BGP3. In contrast, Methanothermobacter members were highly abundant in the thermophilic BGP4. Furthermore, a high consistency between the sequencing approach and the QMF method was shown, especially for the thermophilic BGP. The differences elucidated that using this biphasic approach for mesophilic BGPs provided novel insights regarding disaggregated single cells of Methanosarcina and Methanosaeta species. Both dominated the archaeal subcommunity and replaced coccoid Methanoculleus members belonging to the same group of Methanomicrobiales that have been frequently observed in similar BGPs. This work demonstrates that combining QMF and 16S rRNA gene amplicon sequencing is a complementary strategy to describe archaeal community structures within biogas processes.

• Proceedings of the Korean Biophysical Society Conference
• /
• 2003.06a
• /
• pp.39-39
• /
• 2003

In our previous study, WEHI-231, an immature B cell line, showed intractable increase in [C $a^{2+}$]$_{c}$ after the B-cell receptor (BCR) ligation and treatment with 2-aminoethoxydiphenylborate (2-APB), which was never observed in Bal-17, a mature B cell line (Nam et al., 2003, FEBS Lett). In this study, a whole cell voltage clamp study revealed a specific expression of a novel type of $K^{+}$ current, namely voltage-independent background-type $K^{+}$ channels (IK-bg), in WEHI-231 cells. IK-bg was dramatically increase by the application of 2-APB (50 $\square$M), which induced severe hyperpolarization of WEHI-231 from -45 ㎷ to -90 ㎷, When dialyzed with $Mg^{2+}$ and ATP-free pipette solution, a spontaneous development of IK-bg and membrane hyperpolarization were observed. IK-bg was insensitive to classical $K^{+}$ channel blockers (TEA, glibenclamide, $Ba^{2+}$(1 mM)), whereas blocked by quinine and quinidine in a voltage-dependent manner ($IC_{50}$/=6~9 $\square$M at +60㎷). Phorbol myrstate, a PKC activator, decreased the amplitude of IK-bg. Extracellular acidification (pH 6.5) slightly inhibited IK-bg. Arachidonic acid, riluzole, or hyposmotic stress could not affect the IK-bg after the full development by the intracellular dialysis with Mg-ATP-free solution. In a cell-attached mode of single channel recording from WEHI231, we found two types of voltage-independent $K^{+}$ channels with unitary conductance of 300 pS and 120 pS, respectively. Both channels showed very short mean open times and their open probabilities were increase by the application of 2-APB. In Bal-17 cells, no such $K^{+}$ current was observed in 50 cells tested. In summary, WEHI-231 immature B cells express background $K^{+}$ channels. The pharmacological properties and the large unitary conductance suggest that novel types of two-pore domain $K^{+}$ channels (2-P-K channels) might be expressed in WEHI-231, which may provide an intriguing targets of signal transduction in the immature B lymphocytes.e B lymphocytes.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.31 no.5
• /
• pp.227-234
• /
• 2018

Researches regarding measurement and control of the dynamic behavior of liquid such as sloshing have been actively on undertaken in various engineering fields. Liquid vibration is being measured in the study of tuned liquid dampers(TLDs), which attenuates wind motion of buildings even in building structures. To overcome the limitations of existing wave height measurement sensors, a method of measuring liquid vibration in a TLD using a laser Doppler vibrometer(LDV) and galvanometer scanner is proposed in this paper: the principle of measuring speed and displacement is discussed; a system of multi-point measurement with a single point of LDV according to the operating principles of the galvanometer scanner is established. 4-point liquid vibration on the TLD is measured, and the time domain data of each point is compared with the conventional video sensing data. It was confirmed that the waveform is transformed into the traveling wave and the standing wave. In addition, the data with measurement delay are cross-correlated to perform singular value decomposition. The natural frequencies and mode shapes are compared using theoretical and video sensing results.

• The Journal of the Acoustical Society of Korea
• /
• v.37 no.2
• /
• pp.99-109
• /
• 2018

The precision of the vibration-sensors, contact or non-contact types, is usually satisfactory for the practical measurement applications, but a sensor is confined to the measurement of a point or a direction. Although the precision and frequency span of the low-cost camera are inferior to these sensors, it has the merits in the cost and in the capability of simultaneous measurement of a large vibrating area. Furthermore, a camera can measure multi-degrees-of-freedom of a vibrating object simultaneously. In this study, the calibration method and the dynamic characteristics of the low-cost machine vision camera as a sensor are studied with a demonstrating example of the two-dimensional vibration of a cantilever beam. The planar image of the camera shot reveals two rectilinear and one rotational motion. The rectilinear vibration motion of a single point is first measured using a camera and the camera is experimentally calibrated by calculating error referencing the LDV (Laser Doppler Vibrometer) measurement. Then, by measuring the motion of multiple points at once, the rotational vibration motion and the whole vibration motion of the cantilever beam are measured. The whole vibration motion of the cantilever beam is analyzed both in time and frequency domain.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.4
• /
• pp.128-138
• /
• 2014

Development of infrastructure component libraries is a critical requirement for the accelerated adoption of BIM in the civil engineering sector. Libraries reduce the time for BIM model creation, allows accurate quantity take offs, and shared use of standard models in a project. However, such libraries are currently in very short supply in the domestic infrastructure domain. This research introduces library components for retaining walls and box culverts generated from 2D standard drawings made publicly available by MOLIT. Commercial BIM software was used to create the concrete geometry and rebar, and dimensional/volumetric parameters were defined to maximize the reuse and generality of the libraries. Use of the these libraries in a project context demonstrates that they allow accurate and quick quantity take offs, and easier management of geometric information through the use of a single library as to numerous 2D drawings. It also demonstrates the easy modification of the geometries of the components if and when they need to changed. However, the application also showed that some of the rebar components (stirrups and length wise rebars) do not get properly updated when concrete geometries are changed, demonstrating the limits of current software applications. The research provides evidence of the many advantages of using BIM libraries in the civil engineering, thus providing the incentive for further development of standard libraries and promoting the use of BIM in infrastructure projects.

• ALGAE
• /
• v.29 no.2
• /
• pp.75-99
• /
• 2014

A small dinoflagellate, Ansanella granifera gen. et sp. nov., was isolated from estuarine and marine waters, and examined by light microscopy, scanning electron microscopy, and transmission electron microscopy. In addition, the identity of the sequences (3,663-bp product) of the small subunit (SSU), internal transcribed spacer (ITS) region (ITS1, 5.8S, ITS2), and D1-D3 large subunit (LSU) rDNA were determined. This newly isolated, thin-walled dinoflagellate has a type E eyespot and a single elongated apical vesicle, and it is closely related to species belonging to the family Suessiaceae. A. granifera has 10-14 horizontal rows of amphiesmal vesicles, comparable to Biecheleria spp. and Biecheleriopsis adriatica, but greater in number than in other species of the family Suessiaceae. Unlike Biecheleria spp. and B. adriatica, A. granifera has grana-like thylakoids. Further, A. granifera lacks a nuclear fibrous connective, which is present in B. adriatica. B. adriatica and A. granifera also show a morphological difference in the shape of the margin of the cingulum. In A. granifera, the cingular margin formed a zigzag line, and in B. adriatica a straight line, especially on the dorsal side of the cell. The episome is conical with a round apex, whereas the hyposome is trapezoidal. Cells growing photosynthetically are $10.0-15.0{\mu}m$ long and $8.5-12.4{\mu}m$ wide. The cingulum is descending, the two ends displaced about its own width. Cells of A. granifera contain 5-8 peripheral chloroplasts, stalked pyrenoids, and a pusule system, but lack nuclear envelope chambers, a nuclear fibrous connective, lamellar body, rhizocysts, and a peduncle. The main accessory pigment is peridinin. The SSU, ITS regions, and D1-D3 LSU rDNA sequences differ by 1.2-7.4%, >8.8%, and >2.5%, respectively, from those of the other known genera in the order Suessiales. Moreover, the SSU rDNA sequence differed by 1-2% from that of the three most closely related species, Polarella glacialis, Pelagodinium bei, and Protodinium simplex. In addition, the ITS1-5.8S-ITS2 rDNA sequence differed by 16-19% from that of the three most closely related species, Gymnodinium corii, Pr. simplex, and Pel. bei, and the LSU rDNA sequence differed by 3-4% from that of the three most closely related species, Protodinium sp. CCMP419, B. adriatica, and Gymnodinium sp. CCMP425. A. granifera had a 51-base pair fragment in domain D2 of the large subunit of ribosomal DNA, which is absent in the genus Biecheleria. In the phylogenetic tree based on the SSU and LSU sequences, A. granifera is located in the large clade of the family Suessiaceae, but it forms an independent clade.