• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.273-276
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• 2006

RNA interference (RNAi), a process of sequence-specific gene suppression, has been known as a natural gene regulatory mechanism in a wide range of lower organisms. Recently, we have reported that a transfection of human U6 promoter (hU6) driven hairpin small-interference RNA (siRNA) plasmid specifically knocks down the target gene by post-transcriptional gene silencing in mammalian cells. Here we report that transfection of polymerase chain reaction (PCR) products, containing human U6 promoter with hairpin siRNA, knocks down the target gene expression in human teratocarcinoma NT-2/D1 cells. Moreover, we showed 3' end termination sequence, 5 Ts, is not critical elements for knocking down in PCR-based siRNA system. Therefore, the PCR-based siRNA system is a promising tool not only for the screening but also to temporally regulate gene expression in the human progenitor cells.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.3
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• pp.189-195
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• 2004

The underwater sound of California gary whale was analyzed to discuss obtained results from the previous data to compare the underwater sound between Korean gray whale and California gray whale. The frequency of low frequency rumble which occupy about 50% of the underwater sound changed to max. 654Hz and the average of its lasted time was 570msec. The range of frequency variation was coincided as compared with the previous data. The range of frequency variation for the bubble type sounds and knocks was 24${\sim}$1029Hz, respectively. The average of lasted time was 1100msec and 1364msec, respectively. The range of frequency variation and lasted time of bubble type sounds was higher than the previous result while the sound of knocks was coincided. The range of frequency variation for the sound of bong, pluses and chirps was 34${\sim}$213Hz, 75${\sim}$360Hz and 120${\sim}$200Hz, respectively and the average of lasted time was 84msec, 873msec and 80msec, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.4
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• pp.387-394
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• 2013

Hydrogen-compressed natural gas (HCNG) blend has attracted attention as a fuel that can reduce $CO_2$ emissions because it has low carbon content and burns efficiently. An increase in the compression ratio of HCNG engines was considered as one of the methods to improve their efficiency and reduce $CO_2$ emissions. However, a high combustion rate and flame temperature cause abnormal combustion such as pre-ignition or knocks, which in turn can cause damage to the engine components and decrease the engine power. In this study, the performance and knock characteristics with a change in the compression ratio of an HCNG engine were analyzed. The combustion characteristics of HCNG fuel were evaluated as a function of the excess air ratio using a conventional CNG engine. The effects of the compression ratio on the engine performance were evaluated through the same experimental procedures.

• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.337-343
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• 2020

Oxide dispersed strengthened (ODS) steel is an important candidate for Gen-IV reactors. Oxide embedded in Fe can help to trap irradiation defects and enhances the strength of steel. It was observed in this study that the size of oxide has a profound impact on the depinning mechanism. For smaller sizes, the oxide acts as a void; thus, letting the dislocation bypass without any shear. On the other hand, oxides larger than 2 nm generate new dislocation segments around themselves. The depinning is similar to that of Orowan mechanism and the strengthening effect is likely to be greater for larger oxides. It was found that higher shear deformation rates produce more fine-tuned stress-strain curve. Both molecular dynamics (MD) simulations and BKS (Bacon-Knocks-Scattergood) model display similar characteristics whereby establishing an inverse relation between the depinning stress and the obstacle distance. It was found that (110)_oxide || (111)_Fe (oriented oxide) also had similar characteristics as that of (100)_oxide || (111)_Fe but resulted in an increased depinning stress thereby providing greater resistance to dislocation bypass. Our simulation results concluded that critical depinning stress depends significantly on the size and orientation of the oxide.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1226-1236
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• 2022

Because students majoring in construction-related fields must develop a broad repository of knowledge and skills, effective transferal of these is the primary focus of most academic programs. While inculcation of this body of knowledge is certainly critical, actual construction projects are complicated ventures that involve levels of risk and uncertainty, such as resistant neighboring communities, unforeseen weather conditions, escalating material costs, labor shortages and strikes, accidents on jobsites, challenges with emerging forms of technology, etc. Learning how to develop a level of discernment about potential ways to handle such uncertainty often takes years of costly trial-and-error in the proverbial "school of hard knocks." There is therefore a need to proactively expedite the development of a sharpened intuition when making decisions. The AGC Education and Research Foundation case study committee was formed to address this need. Since its inception in 2011, 14 freely downloadable case studies have thus far been jointly developed by an academics and industry practitioners to help educators elicit varied responses from students about potential ways to respond when facing an actual project dilemma. AGC case studies are typically designed to focus on a particular concern and topics have thus far included: ethics, site logistics planning, financial management, prefabrication and modularization, safety, lean practices, preconstruction planning, subcontractor management, collaborative teamwork, sustainable construction, mobile technology, and building information modeling (BIM). This session will include an overview of the history and intent of the AGC case study program, as well as lively interactive demonstrations and discussions on how case studies can be used both by educators within a typical academic setting, as well as by industry practitioners seeking a novel tool for their in-house training programs.

• Journal of Life Science
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• v.31 no.2
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• pp.115-125
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• 2021

Calcium-dependent protein kinases (CDPKs) are known to be involved in regulating plant responses to abiotic stresses such as salinity, cold temperature and dehydration,. Although CDPKs constitute a large multigene family consisting of 31 genes in rice, only a few rice CDPKs' functions have been identified. Therefore, in order to elucidate the functions of OsCPK11 in rice, this study was intended to focus on the expression pattern analysis of OsCPK11 in wild type and ND0001 oscpk11 mutant plants under these abiotic stresses. For the salt, cold and drought stress treatment, seedlings were exposed to 200 mM NaCl, 4℃ and 20% PEG 6,000, respectively. RT-PCR and quantitative real-time PCR were performed to determine the expression patterns of OsCPK11 in wild type and ND0001 mutant plants. RT-PCR results showed that OsCPK11 transcripts in the wild type and heterozygous mutant were detected, but not in the homozygous mutant. Real-time PCR results showed that relative expression of OsCPK11 of wild type plants was increased and reached to the highest level at 24 hr, at 6 hr and at 24 hr under salt, cold and drought stress conditions, respectively. Relative expression of OsCPK11 of ND0001 homozygous plant was significantly reduced compared to that of wild type. These results suggested that oscpk11 homozygous mutant knocks out OsCPK11 and OsCPK11 might be involved in salt, cold and drought stress signaling by regulating its gene expression.