• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.1-9
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• 2007

Water condensate accumulated on the surface of a fin-and-tube heat exchanger significantly affects its thermal and hydraulic performance. The purpose of this study is to investigate the effect of condensate retention on the air-side heat transfer performance and flow friction. Total 12 samples of slit and plate fin-and-tube heat exchangers with varying fin spacing and number of tube rows are tested under dry and wet conditions. The thermal fluid measurements are made using a psychometric calorimeter. Frontal air velocity varies in the range from 0.7 m/s to 1.5 m/s. Using the experimental data, presented are the heat transfer coefficients in terms of Colburn j-factor and friction factor.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.10-18
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• 2007

The purpose of this study is to develop an user-friendly computer program which can analyze the thermal performance of high-rise curtain wall. In this study, the sub-routines for FVM SOLVER, HIGH-RISE CONDITION CALCULATION, AUTOMATIC SPECIFICATION BOUNDARY/MESH, MATERIAL DATABASE, and GRAPHICAL CONDENSATION/U-FACTOR OUTPUT were developed by using Visual Basic. The curtain wall heat conduction simulation results of program showed good agreement with those of FLUENT and THERM. The minimum and maximum relative error rates were 3.17 and 9.68% compared to other software.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.164-171
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• 2006

Application of friction welding is increasing in the manufacturing process of machine elements in many industry fields. To establish a reasonable strength evaluation method and fracture criterion, it is necessary to analyze stress singularity under the residual stress condition on friction welded interface between dissimilar materials. In this paper, a method to establish fracture criterion on interface of friction welded dissimiliar materials was investigated by using the boundary element method BEM and static tensile testing. A quantitative fracture criterion for friction welded dissimilar materials is suggested by using stress singularity factor, $\Gamma$.

• Journal of Korean Academy of Nursing
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• v.50 no.3
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• pp.487-500
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• 2020

Purpose: This study aimed to evaluate the validity and reliability of the Korean version of Menopause-Specific Quality of Life (MENQOL). Methods: The MENQOL was translated into Korean according to algorithm of linguistic validation process. A total of 308 menopausal women were recruited and assessed using the Korean version of MENQOL (MENQOL-K), the World Health Organization Quality of Life Brief Version (WHOQOL-BREF), and Center for Epidemiological Studies Depression Scale (CES-D-K). In estimating reliability, internal consistency reliability coefficients were calculated. Validity was evaluated through criterion validity and construct validity with confirmatory factor analyses using SPSS 23.0 and AMOS 25.0 software. Results: In item analyses, the "increased facial hair" symptom was excluded because of the low contribution of MENQOL-K. The confirmatory factor analysis supported good fit and reliable scores for MENQOL-K model, and the four-factor structure was validated (χ²=553.28, p<.001, NC=1.84, RMSEA=.05, AGIF=.85, AIC=765.28). The MENQOL-K consists of 28 items in 4 domains, including vasomotor (3 items), psychosocial (7 items), physical (15 items), and sexual subscales (3 items). There was an acceptable criterion validity with moderately significant correlation between MENQOL-K and WHOQOL-BREF. The Cronbach's α for the 4 subsacles ranged from .80 to .93. Conclusion: The MENQOL-K is a valid and reliable scale to measure condition-specific quality of life for perimenopausal and postmenopausal women. It can be used to assess the impact of menopausal symptoms on the quality of life of Korean women in clinical trials.

• The KSFM Journal of Fluid Machinery
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• v.16 no.4
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• pp.35-43
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• 2013

Most of the nuclear power plants(NPPs) adopts pressure difference type flow meters such as venturi and orifice meters for the measurement of feedwater flow rates to calculate reactor thermal power. However, corrosion products in the feedwater deposits on the flow meter by fouling as operating time goes. These effects lead to severe errors in the flow indication and then determination of reactor thermal power. The averaging BDFT, which has developed by Yun et al., has a potentiality to minimize this problem thanks to its inherent measurement principle. Therefore, it is expected that the averaging BDFT can replace the venturi meter for the feedwater pipe of steam generator of NPPs. The present work compares the amplification factor, K, based on CFD calculation against the K obtained from experiments in order to confirm whether a commercial CFD code can be applicable to the evaluation of characteristic for the averaging BDFT. In addition to this, the simulations to take into account of fouling effect are also carried out by rough wall option. The results show that the averaging BDFT is a promising flow meter for the accurate measurement of flow rates in the fouling condition of the NPPs.

• Natural Product Sciences
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• v.24 no.2
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• pp.103-108
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• 2018

The usage of wild ginseng (Panax ginseng C.A. Meyer) has been limited due to short supply and high price. Therefore, sufficient production as well as efficient extraction of mountain ginseng are required for the development as products. In this study, wild ginseng adventitious root cultures were prepared for efficient production with advantages of fast growth and stable production. Treatment of methyl jasmonate (MJ) to wild ginseng adventitious root cultures increased the extraction yield and antioxidative activity. Further investigation on effect of extraction conditions suggested the importance of ethanol concentration on antioxidative activity and extraction yield of MJ-treated wild ginseng adventitious root cultures. Optimized extraction condition of MJ-treated wild ginseng adventitious root cultures for maximum extraction yield and antioxidative activity was determined using response surface methodology with three-level-three-factor Box-Behnken design (BBD). Extraction of 1 g MJ-treated wild ginseng adventitious root culture with 30 ml of 9% ethanol at $30^{\circ}C$ produced 310.2 mg extract with 71.0% antioxidative activity at $100{\mu}g/ml$. Taken together, MJ-treated wild ginseng adventitious root culture is valuable source for wild ginseng usage and optimized extraction condition can be used for the development of functional products or folk remedies.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.107-114
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• 2017

In this paper, a novel power factor compensation system based on voltage-controlled method is proposed for 3-phase 4-wire power system. The proposed voltage-controlled power factor compensation system generates a reactive power required for compensation by applying a variable output voltage by a slidac to a capacitor. In conventional power factor compensation system using the capacitor bank method, the power factor compensation error occurs depending on the load condition due to the limited capacity of the capacitors. However, the proposed system compensates the power factor up to 100% without error. In this paper, we have developed a voltage-controlled power factor compensation system and a control algorithm for 3-phase 4-wire power system, and verify its performance through simulation and experiments. If the proposed power factor compensation system is applied to an industrial field, a power factor compensation performance can be maximized. As a result, it is possible to reduce of electricity prices, reduce of line loss, increase of load capacity, ensure the transmission margin capacity, and reduce the amount of power generation.

• The Korean Journal of Malacology
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• v.32 no.4
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• pp.241-247
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• 2016

Macrophage Migration Inhibitory Factor (MIF) are well-defined role as unique cytokine and critical mediator in acute and chronic inflammatory diseases, autoimmune diseases. In this study, we isolated and characterized a full-length of MIF cDNA from the abalone (Haliotis discus hannai). The full-length cDNA of abMIF was of 1264 bp, consisting of a 5'-terminal UTR of 143 bp, an open reading frame of 360 bp and a 3-terminal UTR of 761 bp. The abalone MIF cDNA encodes a 119-amino acid polypeptide with a calculated molecular mass of 13.4 kDa and isoelectric point of 9.07. Multiple alignments and phylogenetic analysis with the deduced abalone MIF protein and showed strong homology with disk abalone (Haliotis discusdiscus). The deduced amino acid sequence of abMIF exhibited homology with other reported MIFs, such as 80%, with that of other disk abalone H. discus discus MIF gene. Quantitative real-time PCR (qRT-PCR) analysis indicated that abMIF was highly expression observed in hapatopacreas, intestine, foot, and gonad of normal conditioned abalone. Even though AbMIF mRNA level in hemocytes was low under the normal condition, it was sharply up-regulated and reached the maximum at 6 h post-infection with Vibrio parahaemolyticus, and then decreased at 24 h post-infection. This result indicates that abMIF plays an important role in responding in the innate immune system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.2
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• pp.380-388
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• 2005

In this study, the immunological effect of a traditional Korea herbal medicine, Sochungyong-tang (SCRT) that has been widely used for the treatment of various immunological disorders including allergic asthma in Korea, was examined in vitro. In our previous study demonstrated that SCRT decreases the expression of IL-4 mRNA, that plays pivotal role in Th2 cell development, while increases $IFN-{\gamma}{\tilde{a}}expression$, which is one of the key cytokines for Th1 lineage development in Th0 condition. That study strongly implies that SCRT can correct Th2 dominant condition directly affecting to the CD4+ T cell development. Present study designated to further evaluate the SCRT on helper T cell development by monitoring Th1/Th2 specific cytokine secretion patterns in artificially induced Th1 or Th2 polarized condition. The results demonstrated that Th2 cells were dramatically under-populated in Th2 driven condition with SCRT treatment, while Th1 cells were not altered in Th1 skewed condition. Furthermore, under Th2-skewed conditions the levels of and IL-4 were considerably decreased with SCRT treatment. However, the expression of GATA-3, a transcription factor that plays pivotal role in Th2 lineage programming, was not changed with SCRT, suggesting that the suppression of Th2 cell development by SCRT was not mediated by GATA-3. Present study implies that the effect on CD4+ T cell may be the one of key pharmacological effect point for treating IgE medicated allergic asthma by SCRT. These results also suggest that SCRT might be desirable agent for the correction of Th2 dominant pathological disorders.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.595-603
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• 2017

The study is to produced a brain phantom simulating corpus striatum, which can evaluate the progression of parkinson's disease, to investigate possibility of reducing the brain exposure dose to CT while maintaining optimal image quality during PET-CT examinations. CT scans were performed by varying tube voltage (100, 120 kVp) and tube current (80, 140, 200 mAs) with $^{18}F$ FP-CIT injected into the phantom's hot sphere and background (radioactivity ratio 3:1)(reference condition; 120 kVp, 140 mAs). Estimated effective dose was calculated by using conversion factor according to each condition, and image quality was evaluated by setting SNR and CRChot image evaluation factors. Experimental results showed that the predicted effective dose below the CT imaging reference condition was reduced by at least 10% and by up to 60%, and the predicted effective dose beyond the reference condition was increased by 40%. In addition, there was no significant difference between SNR and CRChot of PET images, and it was confirmed that brain dose decreased with decrease of tube voltage and tube current. At the same time, there was no significant change in the quality of the image in terms of SNR and CRChot despite the change in scan conditions. This fact suggests that the quality of the images acquired under the existing dose conditions can be obtained even at low dose conditions and it is expected that it will be possible to use the brain PET-CT scan as a basic data for the research on reduction of dose and improvement of image quality.