• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.430-432
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• 2010

We verified through a noncritical phase-matched second-harmonic generation experiment that the periodically-poled $LiNbO_3$ (PPLN) had a large effective nonlinear optical coefficient, demonstrating that the QPM grating was uniform throughout the entire length of PPLN. The quasi-phase matching temperature was $193.4^{\circ}C$. The maximum SHG output power at the fundamental power of 2.0 W was found to be 18.0 mW; generated second-harmonic beam was found to have no photorefractive effect.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.2
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• pp.157-161
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• 2011

The study for traffic safety improvement is so necessary to minimize the wound of pedestrian at car impact as to prevent pedestrian from this accident. This study aims at analyzing the behavior affected by impact on which car body hits pedestrian. Load and damage of pedestrian are also investigated. This model is the small car body as frame structure. The pedestrian is modeled with dummy by CATIA as Korean standard body style. The ear impacts the side of pedestrian with the speed from 30 to 90km/h. Behavior and damage of pedestrian at impact are analyzed by ANSYS. In case of 30km/h, The maximum pressure of dummy becomes the maximum value of 100MPa after the elapsed time of 0.1second and then seems to remain at 105MPa constantly. In case of 60km/h, its pressure becomes the maximum value of 110MPa at the elapsed time of 0.05second and decreases at 90MPa until the elapsed time of 0.1second. This value fluctuates after the elapsed time of 0.1second. In case of 90km/h, its maximum pressure becomes the maximum value of 155MPa at the elapsed time of 0.07second and fluctuates after the elapsed time of 0.07second until O.3second. This value seems to remain at 100MPa constantly after 0.3second until 0.5second. But this pressure increases suddenly just after 0.5second. Maximum deformations of dummy increase linearly according to elapsed time at hitting velocities of 30, 60 and 90km/h.

• BMB Reports
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• v.46 no.3
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• pp.163-168
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• 2013

The AML1 gene is an essential transcription factor regulating the differentiation of hematopoietic stem cells into mature blood cells. Though at least 12 different alternatively spliced AML1 mRNAs are generated, three splice variants (AML1a, AML1b and AML1c) have been characterized. Here, using the reverse transcription-polymerase chain reaction with outward-facing primers, we identified a novel non-polyadenylated transcript from the AML1 gene, with exons 5 and 6 scrambled. The novel transcript resisted RNase R digestion, indicating it is a circular RNA structure that may originate from products of mRNA alternative splicing. The expression of the novel transcript in different cells or cell lines of human and a number of other species matched those of the canonical transcripts. The discovery provides additional evidence that circular RNA could stably exist in vivo in human, and may also help to understand the mechanism of the regulation of the AML1 gene transcription.

• Journal of Korean Neurosurgical Society
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• v.41 no.4
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• pp.224-229
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• 2007

Objective : Despite improvement of therapeutic regimen, incidence of stroke increases and it remains a leading cause of death. Our study aims at offering variable data on recurrent strokes. Methods : There were 59 patients who admitted from Jan. 2002 to Dec. 2004 due to recurrent strokes. A retrospective longitudinal cohort study was done. Results : Four-hundred-seventy five patients, diagnosed with acute stroke, experienced 491 strokes in 3 years, and there were 75 recurrent strokes [15.3%] in 59 patients. These 59 patients were included in the study. First hemorrhagic cases [H] were 19 [32%], and the first infarction cases [I] were 40 [68%]. Subsequent strokes after first stroke were as follows : $H{\to}H$ 14 [23.7%] cases, $H{\to}I$ 5 [8.5%], $I{\to}H$ 8 [13.6%], $I{\to}I$ 32 (54.2%]. A Cox regression analyses showed that the first type of stroke was a significant factor to the second stroke as follows : if one has had a hemorrhagic stroke, the possibility of second hemorrhagic attack ($H{\to}H$ attack) increase 3.2 times than ischemic type and in ischemic stroke [$I{\to}I$ attack] 3.6 times increased incidence of second ischemic attack. Conclusion : The recurrence rate of stroke was 12.4% [59 of 475 patients]. If the first stroke is hemorrhage or infarction, the next stroke would have high potentiality of hemorrhage, or infarction. The possibility of same type in second stroke Increase over 3 times. In $H{\to}H$ group, the time interval between first and second stroke was shorter and the age of onset was earlier than in $I{\to}I$ group. Moreover, the infarction was more frequent than hemorrhage in multiple strokes. There was a correlation in lacunar type infarction between first and second attack.

• Ocean Systems Engineering
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• v.5 no.3
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• pp.139-160
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• 2015

The global performance of the 5MW OC4 semisubmersible floating wind turbine in random waves was numerically simulated by using the turbine-floater-mooring fully coupled and time-domain dynamic analysis program FAST-CHARM3D. There have been many papers regarding floating offshore wind turbines but the effects of second-order wave-body interactions on their global performance have rarely been studied. The second-order wave forces are actually small compared to the first-order wave forces, but its effect cannot be ignored when the natural frequencies of a floating system are outside the wave-frequency range. In the case of semi-submersible platform, second-order difference-frequency wave-diffraction forces and moments become important since surge/sway and pitch/roll natural frequencies are lower than those of typical incident waves. The computational effort related to the full second-order diffraction calculation is typically very heavy, so in many cases, the simplified approach called Newman's approximation or first-order-wave-force-only are used. However, it needs to be justified against more complete solutions with full QTF (quadratic transfer function), which is a main subject of the present study. The numerically simulated results for the 5MW OC4 semisubmersible floating wind turbine by FAST-CHARM3D are also extensively compared with the DeepCWind model test results by Technip/NREL/UMaine. The predicted motions and mooring tensions for two white-noise input-wave spectra agree well against the measure values. In this paper, the numerical static-offset and free-decay tests are also conducted to verify the system stiffness, damping, and natural frequencies against the experimental results. They also agree well to verify that the dynamic system modeling is correct to the details. The performance of the simplified approaches instead of using the full QTF are also tested.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.519-530
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• 2022

Recent research indicates that lactate promotes the switching of vascular smooth muscle cells (VSMCs) to a synthetic phenotype, which has been implicated in various vascular diseases. This study aimed to investigate the effects of lactate on the VSMC phenotype switch and the underlying mechanism. The CCK-8 method was used to assess cell viability. The microRNAs and mRNAs levels were evaluated using quantitative PCR. Targets of microRNA were predicted using online tools and confirmed using a luciferase reporter assay. We found that lactate promoted the switch of VSMCs to a synthetic phenotype, as evidenced by an increase in VSMC proliferation, mitochondrial activity, migration, and synthesis but a decrease in VSMC apoptosis. Lactate inhibited miR-23b expression in VSMCs, and miR-23b inhibited VSMC's switch to the synthetic phenotype. Lactate modulated the VSMC phenotype through downregulation of miR-23b expression, suggesting that overexpression of miR-23b using a miR-23b mimic attenuated the effects of lactate on VSMC phenotype modulation. Moreover, we discovered that SMAD family member 3 (SMAD3) was the target of miR-23b in regulating VSMC phenotype. Further findings suggested that lactate promotes VSMC switch to synthetic phenotype by targeting SMAD3 and downregulating miR-23b. These findings suggest that correcting the dysregulation of miR-23b/SMAD3 or lactate metabolism is a potential treatment for vascular diseases.

• Journal of the Korean Ceramic Society
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• v.25 no.4
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• pp.335-340
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• 1988

The change in microstructure and the electrical properties of Pb(In1/2Nb1/2)O3-PbTiO3 Ceramics caused by V2O5 addition were studied. The results are ; 1. interability was increased because the mass transport through the second phase formed by V2O5 addition increased. 2. ith addition of V2O5, tetragonality and Curie temperature increased. The maximum value of kp was observed when 0.5wt% of V2O5 was added. 3. he second phase formed by V2O5 accelerated the grain growth, and existed in grain boundary. Electrical properties were changed by corelations between tetragonality and the amount of second phase.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5201-5205
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• 2012

Background: To evaluate the role of the X-ray repair cross complementing group 3 (XRCC3) T241M polymorphism in head and neck cancer susceptibility. Materials and Methods: We performed a meta-analysis of all available studies, which included 3,191 cases and 5,090 controls. Results: Overall, a significant risk effect of the T241M polymorphism was not found under homologous contrast (MM vs TT: OR=1.293, 95% CI=0.926-1.805; TM vs TT: OR=1.148 95% CI=0.930-1.418) and recessive models (MM vs TT+TM): OR=1.170, 95% CI=0.905-1.512, but a significantly increased risk was observed under a dominant model (MM+TM vs TT): OR=1.243, 95% CI=1.001-1.544. In stratified analyses, there were no significant associations for Asians or Caucasians. Conclusion: Our meta-analysis suggested the XRCC3 241M allele (MM+TM) might act as a head and neck cancer risk factor among all subjects, and the effect of T241M polymorphism on head and neck susceptibility should be studied with a larger, stratified population.

• Communications of the Korean Mathematical Society
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• v.18 no.3
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• pp.559-568
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• 2003

We introduce the notion of two-scale convergence for partial differential equations with random coefficients that gives a very efficient way of finding homogenized differential equations with random coefficients. For an application, we find the homogenized matrices for linear second order elliptic equations with random coefficients. We suggest a natural way of finding the two-scale limit of second order equations by considering the flux term.

• Bulletin of the Korean Mathematical Society
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• v.52 no.3
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• pp.987-998
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• 2015

In the paper, the authors discover an integral representation, some inequalities, and complete monotonicity of the Bernoulli numbers of the second kind.