• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.353-365
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• 2021

Previously, we reported that tissue factor (Tf) was included in the list of differentially expressed genes as an upregulated gene in a rejected porcine heart after xenotransplantation into monkey. In this study, we analyzed that expression of Tf in aortic endothelial cells (pAEC) isolated from alpha 1,3-galactosyltransferase knockout pig in response to allogeneic porcine serum and xenogeneic human serum. The consequence was significant upregulation of Tf expression by responding to human serum compared with porcine serum. To analyze the function of Tf gene as a promoter, we constructed reporter vectors for expression of luciferase linked to 1,246 and 787 base pairs of porcine Tf (pTF1246 and pTF787), and 535 base pairs of human TF (hTF535) sequences including putative promoter regions and AP-1 biding site at the 5' end. The reporter vectors were transfected into pAEC including cytomegalovirus enhancer/chicken β-actin (CAG)-luciferase vector as a control. Luciferase assay showed that all of the promoters were insufficient to express luciferase compared with CAG promoter in basic culture conditions. Notably, pTF1246, pTF787, and hTF535 led to a significant increase of luciferase expression in response to human serum compared with porcine serum while no change of CAG. pTF1246 and pTF787 showed higher expression than hTF535. Taken together, our findings suggest that pTF1246 and pTF787 promoters could mediate target gene expression specifically at xenogeneic stress condition.

• Environmental Engineering Research
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• v.12 no.1
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• pp.21-29
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• 2007

For this study, we polymerized polyacrylamide base flocculants (PAA) and tested their properties and settling efficiency as a treatment for potable water. The most common chemicals for potable water treatment in Korea are alum or PAC. However, due to various reasons (such as rainy season or algae), inorganic flocculants cannot be solely depended on to solve all the problems caused by the poor quality of inflow water. When PAA coupled with coagulants in a potable water purification process is used, the turbidity removal efficiency increases by a factor of three on a single chemical system using PAC (Raw water: 5.21 NTU; Treated PAA+PAC: 0.34 NTU; and, Treated PAC: 1.04 NTU). It is possible to offset the toxic effect of residual monomers in treated water using PAA, because the concentrations of residual acrylamide are less than 400 mg/L in the polymer itself and less than $0.04\;{\mu}g/L$ in the treated water base at a dosage of 0.1 mg/L. Therefore, PAAs may be a workable, and dependable, potable water treatment process for the high pollutant level of resource water.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.85-97
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• 2003

In this paper, earthquake response analyses were performed using equivalent linear method at the soil sites classified as soil types III and IV in "Standard Design Loads for Buildings" Soil Factors were back-calculated by using spectral accelerations obtained from the analyses and those values are compared with soil factors described in other domestic seismic guidelines. For buildings which have the natural period higher than 0.9 sec, it was possible to use soil factors of soil types II and III instead of those of soil types III and IV, respectively. Therefore, it can be concluded that seismic base shear force can be overestimated in the current seismic guidelines and the improvement is required. required.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.553-556
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• 1999

This paper presents a proper condition to achieve above 19 % conversion efficiency using PC1D simulator. Cast poly-Si wafers with resistivity of 1 $\Omega$-cm and thickness of 250 ${\mu}{\textrm}{m}$ were used as a starting material. Various efficiency influencing parameters such as rear surface recombination velocity and minority carrier diffusion length in the base region, front surface recombination velocity, junction depth and doping concentration in the Emitter layer, BSF thickness and doping concentration were investigated. Optimized cell parameters were given as rear surface recombination of 1000 cm/s, minority carrier diffusion length in the base region 200 ${\mu}{\textrm}{m}$, front surface recombination velocity 100 cnt/s, sheet resistivity of emitter layer 100 $\Omega$/$\square$, BSF thickness 5 ${\mu}{\textrm}{m}$, doping concentration 5$\times$10$^{19}$ cm$^3$ . Among the investigated variables, we learn that a diffusion length of base layer acts as a key factor to achieve conversion efficiency higher than 19 %. Further details of simulation parameters and their effects to cell characteristics are discussed in this paper.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.1
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• pp.93-102
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• 2000

Processors for a base station controller such as call control processor have to serve usersdemand. Some of processors have been still used for the processing of call and 0&M (operation and maintenance) management by adopting embedded board type. This type can not provide users with a wide variety of environments for testing and debugging. User environments are regarded as a primary system factor in most systems and this is particularly so in designing and implementing the processor for base station controller in mobile communication systems. We describe the design and implementation of new user environment tool named QUEST for the next generation mobile communication system, IMT-2000. The simulation results of performance evaluations demonstrate that our system performs well for a base station controller without performance degradation.

• Journal of the Korean Magnetic Resonance Society
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• v.24 no.4
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• pp.117-122
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• 2020

Transcription factors are proteins that bind specific sites or elements in regulatory regions of DNA, known as promoters or enhancers, where they control the transcription or expression of target genes. MEIS1 protein is a DNA-binding domain present in human transcription factors and plays important roles in various biological functions. The hydrogen exchange rate constants of the imino protons were determined for the wild-type containing the consensus DNA-binding site for the MEIS1 and those of the mutant DNA duplexes using NMR spectroscopy. The G2A-, A3G- and C4T-mutant DNA duplexes lead to clear changes in thermal stabilities of these four consensus base pairs. These unique dynamic features of the four base pairs in the consensus 5'-TGAC-3' sequence might play crucial roles in the effective DNA binding of the MEIS1 protein.

• Journal of Korean Neurosurgical Society
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• v.65 no.3
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• pp.469-478
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• 2022

Objective : Cranial base chordomas are rare, but their treatment is challenging. Tumor recurrence is still common despite improvements in microsurgical techniques and postoperative radiotherapy. We retrospectively analyzed the course of treatment, overall survival, and recurrence/progression of chordomas over the past 10 years. Methods : We retrospectively reviewed 50 patients who underwent surgery at Tianjin Huanhu Hospital between 2010 and 2020 and were pathologically diagnosed with chordomas. Tumor resection was performed within the maximum safe range in all patients; the extent of resection was evaluated by imaging; and the incidence of complications, recurrence or progression, and overall survival were assessed. Results : Fifty patients were divided into the low-risk group (LRG) and high-risk group (HRG) based on the cranial chordoma grading system (CCGS). The Karnofsky Performance Scale scores and gross total resection rate of the LRG were significantly higher than those of the HRG (p<0.05). The incidence of complications and mortality in the LRG were lower than those of HRG. The analysis of cumulative survival and cumulative recurrence free survival/progression free survival (RFS/PFS) showed no statistical differences in the extent of resection for survival, recurrence, or progression. Univariate and multivariate analyses showed that Ki-67 was significantly associated with tumor recurrence and was an independent hazard factor (p=0.02). Conclusion : The CCGS can help neurosurgeons anticipate surgical outcomes. Pathological results are important in evaluating the possibility of tumor recurrence, and postoperative radiotherapy improves overall survival and RFS/PFS.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.266-274
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• 2002

A typical case where the effects of prying in the base angle type anchorage system with expansion bolt. This connection consists of an angle which is attathed to an equipment cabinet and bolted to a concrete slab via an expantion bolt. A seismic analysis of the cabinet may indicate a vertical load, P, transferred to the vertical leg of the angle due to overturning of the cabinet. Due to the eccentricity, b(e), and the continuous beam action in the base member, the load resisted by the bolt will be amplified by a factor λ. Thus, in this study, experimental evaluation of the anchorage system is executed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.544-552
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• 2002

Recommended seismic design guide for the flat bottom vortical-cylindrical oil storage tanks in KS B 6225 is presented. Under earthquake excitations, the hydrodynamic pressure exerted on the tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea, zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described.

• Journal of KSNVE
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• v.4 no.1
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• pp.71-82
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• 1994

We propose a systematic method to select the master states, which are retained in the reduced model after the order reduction process. The proposed method is based on the fact that the range space of right eigenvector matrix is spanned by orthogonal base vectors, and tries to keep the orthogonality of the submatrix of the base vector matrix as much as possible during the reduction process. To quentify the skewness of that submatrix, we define "Absolute Singularity Factor(ASF)" based on its singular values. While the degree of observability is concerned with estimation error of state vector and up to n'th order derivatives, ASF is related only to the minimum state estimation error. We can use ASF to evaluate the estimation performance of specific partial measurements compared with the best case in which all the state variables are identified based on the full measurements. A heuristic procedure to find suboptimal master states with reduced computational burden is also proposed. proposed.