• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.477-478
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• 2005

The devices with a structure of ITO/$Alq_3$/Al were fabricated and their impedance properties were analyzed. It is obtained that an effect of resistance $R_p$ of the device was dominant at the low frequency and the high voltage region, emitting region, and it is ignored at the high frequency region. Capacitance $C_p$ appears intensely in a range of all frequencies of non-emitting region, below turn on voltage.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.972-975
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• 2004

In order to reduce the noise of BLDC motor, a systematic optimization procedure for rotor structure is presented. The noise index is defined as the sum of volume velocity of FE-model that are calculated at the dominant frequencies during dehydration process, which is based on the principle of radiation simple volume source. Then, the five design variables are selected to represent the shape and layout or rotor structure. This discrete design optimization problem for minimizing the noise index is solved by 3-level orthogonal array based effect analysis. Finally, the response surface method (RSM) combined optimization approach is employed for more refining the approximate optimum.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.23-26
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• 2004

A computational analysis has been conducted to investigate the detailed flow structure inside a supersonic cavity. The free stream Mach number and Reynolds number are 1.83 and $6.02\times10^5$ respectively. In the present study, the depth and width of the cavity are changed to investigate the effect of the cavity dimensions. A fully implicit finite volume scheme is applied to solve the three-dimensional, steady, unsteady, compressible, Navier-Stokes equations. The computed results are validated with the previous experimental data available. The present computation provides reasonable predictions of the cavity flow, compared with experimental results. The obtained results show that a shock wave is generated in front of the downstream edge of the cavity and the dominant frequencies of the pressure oscillations inside the cavity were obtained.

• Computers and Concrete
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• v.8 no.4
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• pp.425-443
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• 2011

Most previous studies have generally overlooked the contribution of thermal stresses generated within the concrete mass when subjected to microwave heating and reported on pore-pressure as being the dominant cause of surface spalling. Also, the variation in electromagnetic properties of concrete and its effects on the microwave heating process have not been studied in detail. In this paper, finite element modeling is used to examine the simultaneous development of compressive thermal stresses and pore-pressure arising from the microwave heating of concrete. A modified Lambert's Law formulation is proposed to estimate the microwave power dissipation in the concrete mass. Moreover, the effects of frequency and concrete water content on the concrete heating rate and pattern are investigated. Results show high compressive stresses being generated especially in concrete with a high water content when heated by microwaves of higher frequencies. The results also reveal that the water content of concrete plays a crucial role in the microwave heating process.

• Journal of the Korean earth science society
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• v.35 no.4
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• pp.277-289
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• 2014

The purpose of this study was to analyze the questions of earth science knowledge presented in elementary science textbooks. In group activities, The questions were created by preservice elementary teachers assuming that they were teaching the earth science knowledge in science education classes at university of education. Types, frequencies, and sources of the cognitive background knowledge of the questions were analyzed. The results demonstrated the followings. First, types, concentrations, and sources of the cognitive background knowledge of the questions were different depending on the domains of earth science. Specifically, in astronomy domain, the frequencies and concentrations of the questions showed different trends compared with other domains in its individual lessons. It suggests that instructional strategies that reflected the difference found in each lessons be appropriately designed and used. Second, it was found that 'schools' was the most dominant sources of the cognitive background. 'Friends' were also found to be very important sources, thus promoting students' interaction with their peers would become an important strategy in science teaching. It was also found that mass media such as 'internet' and 'TV' were roughly rated the same as 'schools' which illustrated that mass media could be utilized in science instruction. Third, since types, concentrations, and frequencies of the questions were diverse in the lessons of units, it is suggested that diverse instruction strategies also be taken into account as an educational approach in teaching the subjects in teacher education.

• Annals of Clinical Neurophysiology
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• v.10 no.2
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• pp.104-108
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• 2008

Background: The compression of 7th cranial nerve by arteries is one of the various causes of hemifacial spasm (HFS). A few previous studies were revealed the relation between the compression of 7th cranial nerve and common trunk anomaly. We evaluated the common trunk anomalies in patients with HFS using MRI and MRA. Methods: From January 2001 to December 2005, 41 consecutive patients (9 men, mean age $54.5{\pm}12.6$) with HFS underwent MRI and MRA. T2 axial images and time-of-flight angiographies were reviewed for identification of the compression at root exit zone by two neuroradiologists and one neurologist. Results: Thirty-seven patients showed neurovascular compression on the lesion side. Twenty patients of them were shown the compression of 7th cranial nerve by anterior inferior cerebellar artery (AICA), and seventeen patients of them were shown the compression by posterior inferior cerebellar artery (PICA). Twenty-four patients of the thirty-seven patients had common trunk anomaly. In control, twelve of twenty-one subjects had common trunk anomaly, that the frequencies of common trunk anomaly of two groups were 58.8% in HFS and 57.1% in controls. In the twenty-four patients with common trunk anomaly, eighteen patients had dominant-AICA, and six patients had dominant-PICA. The rate of nerve compression by common trunk anomaly in the HFS with unilateral common trunk, dominant-AICA was 76.5% and dominant-PICA was 100%. Conclusions: This study also revealed that AICA was most common compressive artery. There was no difference between the HFS groups and control groups in frequency of common trunk anomaly. Thus, we could not demonstrate the relationship between common trunk anomaly and HFS.

• Genomics & Informatics
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• v.8 no.4
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• pp.206-211
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• 2010

The Fas (TNF receptor superfamily, member 6) (FAS)/FAS ligand (FASLG) interaction plays a central role in the regulation of programmed cell death. FAS and FASLG polymorphisms in promoter regions affect transcriptional activities. To investigate whether FAS and FASLG polymorphisms are associated with the development and clinical phenotypes of stroke, 2 promoter single nucleotide polymorphisms (SNPs) in FAS (rs1800682, -670C/T) and FASLG (rs763110, -844C/T) were selected and genotyped by direct sequencing in 220 stroke patients [107 ischemic stroke (IS), 77 intracerebral hemorrhage (ICH), and 36 subarachnoid hemorrhage (SAH)] and 369 control subjects. For the analysis of clinical symptoms, all stroke patients were divided into 3 clinical phenotypes according to the respective results of the National Institutes of Health Stroke Survey (NIHSS) and the Modified Barthel Index (MBI) and the presence or absence of complex regional pain syndrome (CRPS). The SNPStats, SNPAnalyzer, and Helixtree programs were used to analyze the genetic data. Multiple logistic regression models (codominant, dominant, and recessive) were used to estimate odds ratios (ORs), 95% confidence intervals (CIs), and p-values. The promoter SNP rs1800682 was associated with stroke in the codominant (OR=0.48, 95% CI=0.25-0.94, p=0.04) and dominant models (OR=0.51, 95% CI=0.30-0.87, p=0.011). However, a FASLG SNP (rs763110) was not in Hardy-Weinberg equilibrium (p<0.05). In the analysis of stroke types, rs1800682 was associated with IS in the codominant (OR=0.30, 95% CI=0.12-0.74, p=0.025), dominant (OR=0.44, 95% CI=0.23-0.88, p=0.018), and recessive models (OR=0.45, 95% CI=0.21-0.99, p=0.042). The genotype frequencies of rs1800682 were different between ICH and controls in the dominant model (OR=0.49, 95% CI=0.26-0.94, p=0.031) but not between SAH and controls. In the analysis of clinical symptoms, however, rs1800682 was not related to the 3 clinical phenotypes (NIHSS, MBI, and CRPS). These results suggest that a promoter SNP (rs1800682, -670C/T) in FAS may be associated with the development of stroke in the Korean population.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.1-16
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• 1996

This study was conducted at an automobile assembly line located in Kyonggi-do, Korea from January 16 to February 28, 1995. The purposes of this study were to assess worker exposures to hand-arm vibration and the performance of gloves for reduction of vibration. The exposure to vibration was measured using to the ISO 5349(1986) method. Vibration acceleration and frequency spectra for each tool were determined on-line replicating actual working conditions and analyzed together with exposure time for evaluating individual worker exposure. Eight pneumatic hand tools, 60 workers exposured to hand-arm vibration, and three pairs of gloves were involved in this study. Results are summarized as follows. 1. Dominant frequencies of vibration for all tools(n=8) measured in this study ranged from 250 Hz to 800 Hz. 2. There was no significant correleration between dominant frequencies and free running speed (p>0.05). 3. Total predicted exposure times of using impact, hammer type did not exceed 40 minutes, but metal finish task, using grinder and sander exceeded 40 minutes. Total exposure time affected significantly the frequency-weighted, 4 hr equivalent acceleration. 4. Predicted prevalence and observed exposure period data were compared in workers(n=60), according to ISO 5349. In this results, 23(50.0 %) and 24(48.07 %) persons exceeded the mean latency periods for vibration-induced white finger(VWF) at 10 % (n=46) and 50 % (n=52) standards, respectively. On the basis of ISO equation, mean latent periods for VWF were 3.23, 4.72 years at 10 %, 50 % standards, respectively. 5. Reduction of vibration by gloves was evaluated. Since impact pneumatic tools produced low frequency vibrations, conventional gloves did not provide any protection. Gloves A and C amplify somewhat the signal at frequency below 400 Hz; the attenuation increases progressively by frequency to reach 18 dB ($7.94{\times}10^{-6}m/s^2$) at 1,000 Hz, slightly worsening Glove B did not provide any protection and made the situation slightly worse. However, since they make the hands warm, the occurrence of vibration-induced white fingers may be reduced.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.313-318
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• 2009

TIAF1 is a TGF-${\beta}$1-induced anti-apoptotic factor that plays a critical role in blocking TNF (tumor necrosis factor) cytotoxicity in mouse fibroblasts and participates in TGF-${\beta}$-mediated growth regulation. In this study, we obtained the full-length cDNA sequence of the porcine TIAF1 gene. Real-time PCR further revealed that the TIAF1 gene was expressed at the highest level in liver and kidney with prominent expressions detected in uterus, and lower levels detected in heart, spleen, lung, stomach, small intestine, skeletal muscle and fat of Large White pigs. Sequence analysis indicated that a 6 base-pair deletion mutation existed in the exon of the TIAF1 gene between Meishan and Large White pigs. This mutation induced deletion of Gln and Val amino acids. PCR-RFLP was used to detect the polymorphism in 394 pigs of a "Large White${\times}$Meishan" $F_{2}$ resource population and four purebred pig populations. The frequencies of the A allele (with a 6 bp deletion) were dominant in Chinese Meishan and Bamei pigs, and the frequencies of the B allele (no 6 bp deletion) were dominant in Large White and Landrace pigs. Association analyses revealed that the deletion mutation had highly significant associations (p<0.01) with meat marbling score of the thorax-waist longissimus dorsi (LD) muscle (MM1) and intramuscular fat percentage (IMF), and significant associations (p<0.05) with carcass length (CL). The results presented here supply evidence that the 6 bp deletion mutation in the TIAF1 gene affects porcine meat quality and provides useful information for further porcine breeding.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.942-948
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• 2005

New polymorphism of major histocompatibility complex B-G genes was investigated by amplification and digestion of a 401bp fragment including intron 1 and exon 2 using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique with two restriction enzymes of Msp I and Tas I in eight breeds of Chinese indigenous chickens and one exotic breed. In the fragment region of the gene, three novel single nucleotide polymorphisms (SNPs) were detected at the two restriction sites. We found the transition of two nucleotides of A294G and T295C occurred at Tas I restriction site, and consequently led to a non-synonymous substitution of asparagine into serine at position 54 within the deduced amino acid sequence of immunoglobulin variable-region-like domain encoded by the exon 2 of B-G gene. It was observed at rare frequency that a single mutation of A294G occurring at the site, also caused an identical substitution of amino acid, asparagine 54-to-serine, to that we described previously. And the transversion of G319C at Msp I site led to a non-synonymous substitution, glutamine 62-to-histidine. The new alleles and allele frequencies identified by the PCR-RFLP method with the two enzymes were characterized, of which the allele A and B frequencies at Msp I and Tas I loci were given disequilibrium distribution either in the eight Chinese local breeds or in the exotic breed. By comparison, allele A at Msp I locus tended to be dominant, while, the allele B at Tas I locus tended to be dominant in all of the breeds analyzed. In Tibetan chickens, the preliminary association analysis revealed that no significant difference was observed between the different genotypes identified at the Msp I and Tas I loci and the laying performance traits, respectively.