• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.43-51
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• 2018

In order to systematically and scientifically manage the organic and heavy metals against sediment at Daecheon Port, this study conducted particle composition, organic materials and heavy metals irradiation studies of sediments. Analysis of the grain size composition of sediments in the target study area showed the distribution characteristics of the mix of sand, silt and clay. That is, Station C (Stn. C) showed superior by fine-grained sediment, Station A and B (Stn. A and B) showed superior by coarse-grained sediment. The organic matter(COD, TOC, and IL) of Stn. C was appeared to be heavily polluted more than Stn. A and B. These data for the spatial properties in sediment showed that organic matter was related positively to the sediment silt-clay content. Also, in the case of heavy metals contamination in surface sediments, Stn. C was higher than Stn. A and B. Particularly, at the Stn. C, high organic matter concentration and C/N ratio value( >10) indicated that the sediment was composed highly of land-derived organic matter. From these results, it considered that the correlation analysis among to silt-clay, organic matter and heavy metal was found to have a good interrelationship.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.311-318
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• 1994

We fabricated fiber-optic polarizers utilizing polarization selective mode coupling between the guided mode of a fiber and the surface plasmon mode supported by a thin aluminium film deposited on the polished side of a fiber. AI thin films with various thicknesses were coated onto the 633 nm, 830 nm, 1.3 fJITI single mode fibers. The maximum extinction ratio was higher than 30 dB for most of the samples and the best result was 42 dB at 90 A film thickness, with 1.3 fJITI single mode fiber. The insertion loss ranged from 0.2 dB to 1.5 dB.1.5 dB.

• Journal of the Korea Concrete Institute
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• v.17 no.5 s.89
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• pp.843-852
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• 2005

Presently, test results and stress-strain models for poorly confined high-strength columns, more specifically for columns with a tie volumetric ratio smaller than $2.0\%$, are scarce. This paper presents test results loaded in axial direction for square reinforced concrete columns confined by various volumetric ratio lateral ties including low-volumetric ratio. Test variables include concrete compressive strength, tie yield strength, tie arrangement type, and tie volumetric ratio. Local strains measured using strain gages bonded to an acryl rod. For square RC columns confined by lateral ties, the confinement effect was efficiently improved by changing tie arrangement type from Type-A to Type-B. A method to compute the stress in lateral ties at the concrete peak strength and a new stress-strain model for the confined concrete are proposed. Over a wide range of confinement parameters, the model shows good agreement with stress-strain relationships established experimentally.

• Journal of Korean Neurosurgical Society
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• v.41 no.5
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• pp.301-305
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• 2007

Objective : The postoperative subsidence of anterior cervical interbody fusion for cervical degenerative diseases gives rise to segmental kyphotic collapse, screw loosening, and chronic neck pain. So, intraoperative custom-made polymethylmethacrylate [PMMA] C-cage has been developed to prevent subsidence following anterior cervical fusion. Methods : A total of patients who underwent anterior cervical interbody fusion with a intraoperative custom - made cervical cage filled with local bone and demineralized bone matrix [group A] were analyzed prospectively from June 2004 to June 2005. These were compared with 40 patients who were treated with iliac bone graft [group B]. We evaluated subsidence ratio, change of segmental angle, distraction length and segmental angle. Statistical analysis was performed using independent sample t-test and Pearson correlation coefficient. Results : Group A had a statistically significant decrease in subsidence ratio [$0.64{\pm}0.43%$, p=0.00]. distraction length [$2.42{\pm}1.25\;mm$, p=0.02], and follow angle change [$1.78{\pm}1.69^{\circ}$, p=0.01] as compared with Group B. However, there was no statistically significant difference in postoperative segmental angle change [p=0.66]. On the analysis of the correlation coefficient, the parameters showed no interrelationships in the group A. On the other hand, subsidence ratio was affected by distraction length in the group B [Pearson correlation=0.448]. Conclusion : This operative technique would be contributed for the reduction of a postoperative subsidence after the anterior cervical interbody fusion procedure for cervical disc disease with moderate to severe osteoporotic condition and segmental loss of lordosis.

• The Korean Journal of Ecology
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• v.15 no.3
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• pp.311-328
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• 1992

In other to classify calcicoles and calcifuges and calcifuges within plant communities occurring on limestone and granite soils in chungbuk province, korea, soil propertile, constancy for species by prsence or absence, and ratios of soluble to insoluble $Ca^{2+}$ and $Mg^{2+}$ were investigated. In the limestone soils ph values and $Ca^{2+}$ and $Mg^{2+}$ content, ranging 7.26 ~7.48, 5.32~7.37 mg $Ca^{2+}/g$ and 0.42~0.62 mg $Mg^{2+}/g$, respectively, were higher than those in the granite soil with ph 5.76, 1.03mg $Ca^{2+}/g$ and 0.24mg $Mg^{2+}/g$. species with high constancy in the 5 communities were classified into three groups; species group a(29~36% of total number of species) was composed of species occuring on the granite soil; group c(16~24%) is commonly distributed throughout both soils. Ratios of soluble to insoluble $Ca^{2+}$ and $Mg^{2+}$ ranged from 0.1 to 81.3 in the group a, 0.2 to 0.8 in the group b and 0.2 to 8.7 in the group c. species within each group can be divided into two groups based on the values of the ratio, below or above 1.0. consequently, each of the group a and c was classified again into two groups; the group a1 and c1 with the ratio of above 1.0 and the group a2 and c2 withbelow 1.0 but the ratio could not further subdivide the group b. from these results it was proposed that plants of the group a1 were termed as obligate calcicoles, the group b as obligate calcifuges, the group c1 as facultative calcicoles, the group c2 as facultative calcifuges and the group a2 as avoiding calcifuges.

• Journal of Korean Medical classics
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• v.34 no.4
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• pp.65-78
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• 2021

Objectives : This study aims to provide a methodology for effectively searching similar applications of formulas by comparing applications of pre-existing prescriptions and those applied clinically based on the difference in weight ratio of each medicinal. Methods : The clinical application part was substituted by prescriptions from the Donguibogam. Samples of pre-existing prescriptions were taken from the Bangyakhappyeon. The component ratio of Donguibogam prescriptions(Y) and Bangyakhappyeon prescriptions(X1, X2) were calculated and expressed as Y = a×X1 +b×X2 + α. (a,b: numbers, α: the rest) Results : 1. In order to express the component ratio based on arbitrary prescriptions as standard prescription, a system that incorporates a storage sector for pre-existing prescription data, an input sector for arbitrary prescription data, an analysis sector that compares the two, and an output sector that generates analysis results is required. 2. The current study shows that the suggested analysis method allows for two standard prescriptions to an arbitrary prescription. Therefore, it is possible to analyze prescriptions that are combinations of two standard prescriptions. 3. Based on arbitrary prescription(Y) and pre-existing prescription(X1, X2), the combinations could be expressed as Y= a×X1 + b×X2 + α. Through finding the most simple combination, it is possible to search the most similar application to each arbitrary prescription.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.171-181
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• 2022

Purpose: In this paper, we show our blending ratio of 10 types of Essential Oils that survives beneficial bacteria and kills harmful bacteria in the scalp, and we investigate the possibility of application of our blending ratio to the development of anti-dandruff products and the possibility of being used as a raw material for clinical beauty and customized cosmetics. Methods: The scalp microorganisms used in our study were M. furfur, S. epidermidis, E. coli, and P. nitroreducens. There are a total of 10 Essential Oils such as True Lavender, Lime, Roman chamomile, Rosemary camphor, Cedarwood, Geranium, Clove, Tea tree, Palmalosa, and Peppermint. The antibacterial test of the blended Essential Oil was carried out according to the test method of the standardized evaluation methodology of "Food and Food Additives Code". Since M. furfur is related to the growth of sebum in the scalp, in this study we used the fnLNB and the fnLNA with 20 ㎖ of whole fat cow milk added. Results: The blending ratio of EO, which inhibits dandruff-causing bacteria such as M. furfur, S. epidermidis, E. coli, and does not inhibit P. nitroreducens showing dominant growth in a healthy scalp, was B8(Clove 0.2%, Roman chamomile 0.5%, Tea tree 0.3%), B9(Geranium 0.1%, Palmarosa 0.1%, Roman chamomile 0.5%, Tea tree 0.3%), B10(Clove 0.1%, Geranium 0.1%, Palmarosa 0.1%, Roman chamomile 0.5%, Tea tree 0.2%). Conclusion: It is thought that the blending ratio of BEO obtained as a result of this study can provide a basis for use as an alternative to antibiotics in developing anti-dandruff drugs and emerge as a new alternative to solve scalp microbial imbalance. In order for EO to be used as a useful raw material for anti-dandruff preparation, researches on 1) Standardization (the effects of products differ according to the types, regions, climate, extraction methods, etc.), 2) Antimicrobial effects, 3) Safety, etc., must be established.

• Journal of Korean Society of Steel Construction
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• v.13 no.3
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• pp.301-311
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• 2001

For a rectangular-highrise building with aspect ratio about six, the resonant wind speed of wind-induced vibration or galloping start wing speed can be within the design wind speed. The wind-induced vibration and galloping of highrise building with aspect ratio $H/\sqrt{DB}=6$, side ratio D/B=1 to 2 at intervals of 1/4 D/B were investigated in smooth flow. For the reducing effect of wind-induced vibration of highrise building, rectangular-highrise building with corners cutting about side ratio D/B=2 were investigated. Experimental results show that in the smooth flow non corners-cutting cases have tendency of increasing wind-induced vibration and galloping vibration then corner-cutting section. Therefore, the wind-induced vibrations on rectangular-highrise buildings were reduced effectively by using corner cut method.

• Clinical and Experimental Pediatrics
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• v.59 no.4
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• pp.183-189
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• 2016

Purpose: This study aimed to evaluate the correlation, according to postnatal age, between plasma B-type natriuretic peptide (BNP) levels and echocardiographic parameters for the assessment of patent ductus arteriosus (PDA) in preterm infants with respiratory distress. Methods: We enrolled 42 preterm infants with respiratory distress who underwent serial echocardiographic evaluation with simultaneous plasma BNP measurements until ductal closure. The correlations between BNP levels and the following 4 representative echocardiographic parameters were studied: diameter of the ductus arteriosus (DA), ratio of the left atrial diameter to the aortic diameter (LA/Ao), ratio of the PDA diameter to the infant's left pulmonary artery diameter (PDA/LPA), and the antegrade diastolic flow of LPA (DFLPA). Results: BNP levels were significantly correlated to the magnitude of the ductal shunt, comprising the DA diameter, PDA/LPA ratio, LA/Ao ratio, and antegrade DFLPA for the overall study period. The earliest significant correlation, starting from postnatal day 2, was observed between the LA/Ao ratio and BNP levels. The PDA/LPA ratio and the antegrade DFLPA showed significant correlations with BNP levels postnatal day 3 onward, and with the DA diameter, postnatal day 5 onward. Conclusion: BNP levels and echocardiographic parameters showed a positive correlation, but the significance of the correlations differed according to the postnatal age, especially during the first few days of life.

• Journal of Advanced Navigation Technology
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• v.25 no.3
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• pp.229-235
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• 2021

This paper proposes a method of implementing an unequal power divider for high splitting ratios by using transmission lines connected with open and short stubs. The proposed method is an equivalent circuit analysis of a transmission line with an additional port so that it can be converted to an arbitrary impedance in the center of a 2-port transmission line and a 3-port transmission line with an open or short stub connected in parallel to each port. To prove the validity of this method, a Wilkinson power divider with k² = 20 dB splitting ratio and a Gysel power divider with k² = 17 dB splitting ratio were designed at a center frequency of 1 GHz using a 3-port transmission line equivalent circuit. The experimental results of the electrical characteristics are in good agreement with the simulation.