• Journal of the Korean Mathematical Society
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• v.50 no.1
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• pp.203-218
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• 2013

Let R be a ring. A right R-module M is called GI-flat if $Tor^R_1(M,G)=0$ for every Gorenstein injective left R-module G. It is shown that GI-flat modules lie strictly between flat modules and copure flat modules. Suppose R is an $n$-FC ring, we prove that a finitely presented right R-module M is GI-flat if and only if M is a cokernel of a Gorenstein flat preenvelope K ${\rightarrow}$ F of a right R-module K with F flat. Then we study GI-flat dimensions of modules and rings. Various results in [6] are developed, some new characterizations of von Neumann regular rings are given.

• Bulletin of the Korean Mathematical Society
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• v.31 no.2
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• pp.210-214
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• 1994

The purpose of this paper is to investigate the relationship between the depths of the Rees algebra R[It] and the associated graded ring g $r_{I}$(R) of an ideal I in a local ring (R,m) of dim(R) > 0. The relationship between the Cohen-Macaulayness of these two rings has been studied extensively. Let (R, m) be a local ring and I an ideal of R. An ideal J contained in I is called a reduction of I if J $I^{n}$ = $I^{n+1}$ for some integer n.geq.0. A reduction J of I is called a minimal reduction of I. The reduction number of I with respect to J is defined by (Fig.) S. Goto and Y.Shimoda characterized the Cohen-Macaulay property of the Rees algebra of the maximal ideal of a Cohen-Macaulay local ring in terms of the Cohen-Macaulay property of the associated graded ring of the maximal ideal and the reduction number of that maximal ideal. Let us state their theorem.m.m.

• Development and Reproduction
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• v.15 no.4
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• pp.331-338
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• 2011

MicroRNAs (miRNAs) function as a key regulator of diverse cellular functions. To find out novel miRNAs that promote the differentiation of mouse embryonic stem cells (mESCs), we compared the miRNAs expression profiles of mESCs under self-renewal vs. differentiation states. We noticed that miR-222 was highly expressed during the differentiation of mESCs. Quantitative RT-PCR analysis revealed that expression of miR-222 was up-regulated during the embryonic bodies formation and retinoic acid -dependent differentiation. When miR-222 was suppressed by antogomiR-222, the differentiation of mESCs was delayed compared to control. Self-renewal marker expression or cell proliferation was not affected but the expression of lineage specific marker was suppressed by the treatment of miR-222 inhibitor during the differentiation of mESCs. Taken together, these results suggest that miR-222 functions to promote the differentiation of mESCs by regulating expression of differentiation related genes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.917-923
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• 2014

Chondrosarcomas are malignant cartilage-forming tumors of bone which exhibit resistance to both chemotherapy and radiation treatment. miRNAs have been well demonstrated to regulate gene expression and play essential roles in a variety of biological processes, including proliferation, differentiation, migration, cell cycling and apoptosis. In this study, we obtained evidence that miR-100 acts as a tumor suppressor in human chondrosarcomas. Interestingly, cisplatin resistant chondrosarcoma cells exhibit decreased expression of miR-100 compared with parental cells. In addition, we identified mTOR as a direct target of miR-100. Overexpression of miR-100 complementary pairs to the 3' untranslated region (UTR) of mTOR, resulted in sensitization of cisplatin resistant cells to cisplatin. Moreover, recovery of the mTOR pathway by overexpression of S6K desensitized the chondrosarcoma cells to cisplatin, suggesting the miR-100-mediated sensitization to cisplatin dependent on inhibition of mTOR. In summary, the present studies highlight miR-100 as a tumor suppressor in chondrosarcoma contributing to anti-chemoresistance. Overexpression of miR-100 might be exploited as a therapeutic strategy along with cisplatin-based combined chemotherapy for the treatment of clinical chondrosarcoma patients.

• East Asian mathematical journal
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• v.40 no.1
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• pp.1-23
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• 2024

Let M be a semi-invariant submanifold of codimension 3 with almost contact metric structure (𝜙, 𝜉, 𝜂, g) in a complex space form M_n+1(c). We denote by A, K and L the second fundamental forms with respect to the unit normal vector C, D and E respectively, where C is the distinguished normal vector, and by R_𝜉 = R(𝜉, ·)𝜉 the structure Jacobi operator. Suppose that the third fundamental form t satisfies dt(X, Y) = 2𝜃g(𝜙X, Y) for a scalar 𝜃(≠ 2c) and any vector fields X and Y , and at the same time R_𝜉K = KR_𝜉 and ∇_{𝜙∇𝜉𝜉}R_𝜉 = 0. In this paper, we prove that if it satisfies ∇_𝜉R_𝜉 = 0 on M, then M is a real hypersurface of type (A) in M_n(c) provided that the scalar curvature $\bar{r}$ of M holds $\bar{r}-2(n-1)c{\leq}0$.

• Korean Journal of Veterinary Service
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• v.38 no.2
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• pp.101-106
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• 2015

Murine mycoplasmosis, caused by Mycoplasma (M.) pulmonis, is a prominent disease in rodent animals. The aim of this study was to develop a sensitive and specific PCR assay to detect M. pulmonis in animals and to assess the suitability of this assay for the detection of mycoplasmal infection in rats experimentally infected with M. pulmonis. A new PCR assay using the M. pulmonis-specific primer pairs MPul-F and MPul-R was developed. The primers and probe for the assay were designed from regions in the 16S rRNA gene that are unique to M. pulmonis. The novel PCR assay was very specific and sensitive for M. pulmonis, detecting the equivalent of 5 pg of target template DNA. It detected only M. pulmonis and no other Mycoplasma species or other bacterial species. The newly developed PCR assay also effectively detected M. pulmonis infection in rats. These results suggest that this PCR assay using M. pulmonis-specific primer pairs of MPul-F and MPul-R will be useful and effective for monitoring M. pulmonis infection in animals.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.301-307
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• 2018

Unmanned Aerial Vehicles (i.e., drone) are gaining a lot of interest from a wide range of application domains such as infrastructure monitoring and parcel delivery service. In those service scenarios, multiple UAVs are involved and should be reliably operated by so-called UAV management system. For that, we propose oneM2M standard based UAV management and control system which is specifically targeted at traffic management of low-altitude UAVs. In this paper, we include oneM2M platform architecture and its implementation for UAV management system in conjunction with UAV interworking procedure.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.1
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• pp.59-67
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• 2009

Objectives : This research aimed to evaluate the effects of Rubus coreanus $M_{IQ}$. Methods: These extracts from fresh R. coreanus $M_{IQ}$. were investigated with radical scavenging activity, the content of total phenolics, ferric thiocyanate method and flavonoid contents Results: These results revealed that the ethyl acetate extract from fresh R. coreanus $M_{IQ}$. possesses remarkable radical scavenging activity. The content of total phenolics of the ethanol extract from dried R. coreanus $M_{IQ}$. ($IC_{50}$=155.87${\pm}$8.8${\mu}$g/mL) is the highest among all of the samples. The stronger radical-scavenging activity ($IC_{50}$=77.72${\pm}$2.1${\mu}$g/mL) of ethyl acetate extract from dried R. coreanus $M_{IQ}$. should be related to its phenolic content as measured by gallic acid test. Conclusion: These results suggest that dried R. coreanus $M_{IQ}$. may act as a potential antioxidant agent.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.1
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• pp.22-30
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• 2008

Purpose: The purpose of this study is to compare three different CAD/CAM systems through the fracture strength of zirconia core and to evaluate the clinical availability of each system. Material and methods: The following three groups of 30 maxillary mesial incisor core for all-ceramics(each group 10) were fabricated as follows: group 1. $Adens^{(R)}$ CAD/CAM system, group 2. $Cerasys^{(R)}$ CAD/CAM system, group 3. 3M $Lava^{(R)}$ CAD/CAM system. All specimens were manufactured consistently thickness 0.5mm and relief $40{\mu}m$. Specimens were subjected to compressive loading on the lingual area by Z250/$SN5S^{(R)}$. Each group's mean and standard deviation were calculated and Kruskal Waillis test, Wilcoxon Rank Sum test were utilized to find out the relationship among the groups. Results: The results were as follows: 1. The mean fracture strength of $Adens^{(R)}$ system was $615.89{\pm}156.1N$, the $Cerasys^{(R)}$ system was $863.98{\pm}151.5N$, and the 3M $Lava^{(R)}$ system was $1143.1{\pm}286.6N$. 2. The fracture strength of the systems showed the significant statistical differences in order of 3M $Lava^{(R)}$ system, $Cerasys^{(R)}$ system, $Adens^{(R)}$ system. Conclusion: In this study, in spite of the differences among the groups, every group showed clinically useful results. It is necessary to study further clinical experiments on a long term basis.

• Journal of Information Display
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• v.11 no.1
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• pp.24-27
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• 2010

A novel stereo 3D LCD for passive interference filter glasses is presented. A demonstrator based on a standard 120Hz LCD was set up. Stereoscopic image separation was realized in a time-sequential mode using a LED-based scanning backlight with two complementary spectra. A stereo brightness of 3 cd/$m^2$ and a channel separation of 30:1 were achieved.