• Geomechanics and Engineering
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• v.32 no.3
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• pp.245-254
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• 2023

Through qualitative analysis and quantitative analysis, the contradictory conclusions about the stability of the settled goaf with two-layer coal seams subject to building load were obtained. Therefore, it is necessary to combine the additional stress method and numerical simulation to further analyze the foundation stability. Through borehole analysis and empirical formula analogy, the height of water-conducting fracture zone in No.4 coal and No.9 coal were obtained, providing the calculation range of water-conducting fracture zone for numerical simulation. To ensure the accuracy of the elastic modulus of broken gangue, the stress-strain curve were obtained by broken gangue compression test in dried state of No.4 coal seam and in soaking state of No.9 coal seam. To ensure the rationality of the numerical simulation results, the actual measured subsidence data were retrieved by numerical simulation. FISH language was used to analyze the maximum building load on the surface and determine the influence depth of building load on the foundation. The critical building load was 0.16 MPa of No.4 settled goaf and was 1.6 MPa of No.9 settled goaf. The additional stress affected the water-conducting fracture zone obviously, resulted in the subsidence of water-conducting fracture zone was greater than that of bending subsidence zone. In this paper, the additional stress method was analyzed by numerical simulation method, which can provide a new analysis method for the treatment and utilization of the settled goaf.

• Geomechanics and Engineering
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• v.34 no.2
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• pp.155-171
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• 2023

Aiming at the grouting treatment of water inflow in karst conduits, a visualized experiment system for conduit-type grouting blocking was developed. Through the improved water supply system and grouting system, and the optimized multisource information monitoring system, the real-time observation of diffusion and deposition of slurry, and the data acquisition of pressure and velocity during the whole process of grouting were realized, which breaks through the problem that the monitoring element is easy to fail due to slurry adhesion in conventional test system. Based on the grouting experiments in static and flowing water, the diffusion and deposition behavior of the quick-setting slurry under different working conditions were analyzed. The temporal and spatial variation behavior of the pressure and velocity were studied, and the blocking mechanism of the grouting were further revealed. The results showed that: (1) Under the flowing water condition, the counter-flow diffusion distance of slurry was negatively correlated with the flow water velocity and the volume ratio of cement and sodium silicate (C-S ratio), and positively correlated with the grouting volume. The slurry deposition thickness was negatively correlated with the flowing water velocity, and positively correlated with the grouting volume and C-S ratio. (2) The pressure increased slowly before blocking of the flowing water and rapidly after blocking in karst conduits. (3) With the continuous progress of grouting, the flowing water velocity decreased slowly first, then significantly, and finally tended to be stable. According to the research results, some engineering recommendations were put forward for the grouting treatment of the conduit-type water inflow disaster, which has been successfully applied in the treatment project of the China Resources Cement (Pingnan) Limestone Mine. This study provided some guidance and reference for the parameter optimization of grouting for the treatment projects of water inflow in karst conduits.

• Bulletin of the Korean Mathematical Society
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• v.52 no.5
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• pp.1401-1422
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• 2015

Under the restriction of finite order, we prove two uniqueness theorems of nonconstant meromorphic functions sharing three values with their difference operators, which are counterparts of Theorem 2.1 in [6] for a finite-order meromorphic function and its shift operator.

• Bulletin of the Korean Mathematical Society
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• v.51 no.6
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• pp.1773-1789
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• 2014

We study the normality of families of meromorphic functions sharing a set consisting of two or three distinct finite values to improve and extend Theorem 1 in Liu-Pang [15] and Theorem 1.1 in Liu-Chang [16]. Examples are provided to show that the results in this paper, in a sense, are the best possible.

• Communications of the Korean Mathematical Society
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• v.31 no.3
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• pp.467-481
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• 2016

We study the uniqueness question of transcendental meromorphic functions that share three values CM in some angular domains instead of the whole complex plane. The results in this paper extend the corresponding results in Zheng [13, 14] and Yi [12]. Some examples are given to show that the results in this paper, in a sense, are the best possible.

• Kyungpook Mathematical Journal
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• v.61 no.3
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• pp.495-512
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• 2021

We study the value distribution theory of L-functions and completely resolve a question from Yang [10]. This question is related to L-functions sharing three finite values with meromorphic functions. The main result in this paper extends corresponding results from Li [10].

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.1
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• pp.136-144
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• 2014

This paper studied what kind of effects were made through Open Sky agreement on Korea-China air transport market. To analyze the effects on air transport markets brought by liberalization, this paper studied transport volume, number of airlines, passenger and cargo and routes from 2000 to 2012 Korea-China aviation statistics. Liberalization of shandong and Hainan Provinces agreed in 2006 caused significant differences in frequencies, transport volume, and the number of routes for both passenger and cargo services between 2007 and 2008, as well as statistically significant effects. The analysis on the effect of Korea-China Open skies Agreement between 2000 and 2012 was no difference because the global financial crisis in September 2008.

• Kyungpook Mathematical Journal
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• v.48 no.4
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• pp.623-636
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• 2008

In this paper, we prove some results on uniqueness of meromorphic functions with three weighted sharing values. The results in this paper improve those given by H. X. Yi, I. Lahiri, T. C. Alzahary and H. X. Yi and other authors.

• Biomedical Science Letters
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• v.21 no.2
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• pp.69-76
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• 2015

Cervical cancer is the third most common cancer in women worldwide and there is a significant association between human papillomavirus (HPV) infection and cervical cancer. Certain HPV groups, labeled high-risk (HR) HPV groups, are strongly associated with malignancies of the human cervix. HPV prevalence and genotype distribution were analyzed using the REBA $HPV-ID^{(R)}$ (YD Diagnostics, Yongin, Korea) assay based on the reverse blot hybridization assay (REBA) with a total of 324 liquid-based cytology samples from women in Western Shandong Province, East China and results were compared with cytological diagnosis. Most of the HPV genotypes that were detected in high-grade cervical lesions were HR-HPV genotypes such as HPV 16, 18, 33, 53, and 58. The prevalence of these HR-HPV genotypes increased in high-grade cervical lesions. However, from low- to high-grade cervical lesions, the ability to detect LR-HPV genotypes decreased. Additionally, in general, the single HPV genotype infection rate increases in proportion to the severity of the lesion. The study findings suggest that a currently available preventive vaccine against HPV 16 and 18 may have limited effectiveness for prevention of all HPV infection in this province. Finally, based on these findings, these data could guide national or regional vaccination programs in the Western Shandong Province of East China to substantially reduce the burden of cervical lesions.

• Journal of the Korean Society of Food Culture
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• v.37 no.5
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• pp.438-445
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• 2022

Laminaria japonica is a type of brown algae widely consumed in Asian countries and contains many essential nutrients and exhibits anti-obesity, antioxidant, and anti-inflammatory effects. In this study, the antioxidant and immunomodulatory effects of a Laminaria japonica water extract (LJE) were investigated using an in vitro model. Mean total polyphenol content of LJE was 2.16±0.11 ㎍ GAE/mg, and LJE dose-dependently inhibited ABTS radical activity but did not scavenge DPPH radicals. In addition, LJE enhanced nitric oxide (NO) production and upregulated the mRNA expressions of proinflammatory cytokines (i.e., tumor necrosis factor-α and interleukin-6) in RAW 264.7 cells. On the other hand, LJE inhibited NO production and downregulated proinflammatory cytokine mRNA levels in endotoxin-stimulated RAW 264.7 cells. Thus, our data show that LJE has moderate antioxidant activity and biphasic immunomodulatory effects on RAW 264.7 cells. In summary, the study indicates that LJE has potential therapeutic use as a novel biphasic immuno-modulator.