• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.5
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• pp.513-520
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• 2003

In this paper, a novel design concept of frequency doubler using feedforward technique and DGS microstrip line is proposed. The feedforward loop plays a role of fundamental frequency suppression and DGS microstrip line suppresses over the 3rd order harmonic components. By using this new concept, the high suppression for the undesired signals could be achieved easily. The proposed technique is experimentally demonstrated in 1.87 GHz-to-3.74 GHz frequency doubler. The output power of -3 dBm at the frequency of 3.74 GHz(2f$\_$0/) is measured with 42.9 dB suppression of the fundamental frequency signal(f$\_$0/), 20.2 dB suppression of the 3rd harmonic signal(3f$\_$0/) and B9.7 dB suppression of the 4th harmonic signal(4f$\_$0/). The conversion loss of -2.34 dB ∼ -5.8 dB at the bandwidth of 100 MHz, the phase noise of -97.51 dB/Hz(＠10 kHz) were measured.

• The Journal of the Petrological Society of Korea
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• v.14 no.2 s.40
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• pp.108-115
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• 2005

Gyeonggi metamorphic complex in the Gwangju area include banded biotite gneiss and quartzofeldspathic gneiss. Detailed structural analysis suggests that structural elements in the study area were formed by at least five phase of deformations. Penetrative compositional foliations(S1) formed in the banded gneiss during the first metamorphism and deformation (D1). After intrusion of plutonic rocks, the second deformation (D2) produced S2 foliations in the banded gneiss and quartzofeldspathic gneiss during the second metamorphism. D3 structures are represented by isoclinal folds (F3) whose axial surfaces are parallel to S3 foliations. The N-S oriented shortening (D4) was accommodated by closed upright F4 fold with about 100m of axial surface separation. F4 fold is refolded by regional F5 folding resulting in different orientation and fold style of F4 fold according to the position of F5 fold. The F4 fold with tight interlimb angle is subparallel to the axial surface (north-south) of F5 fold in the core of the F5 fold. In contrast the F4 fold trends northeast in the western limb and northwest in the eastern limb of F5 fold. The interlimb angle is larger in the limbs than that in the core of F5 fold. The trace of foliations is constrained by mainly F4 and F5 folds. Joint fanning around fold is developed in the limbs of F5 fold and bc joints are dominant in the hinge area of F5 fold. A strike-slip fault had developed in tile central part of the study area after F5 folding. The orientation of joint and foliation is rotated anticlockwise about $15^{\circ}$ by the landslide occurred during the Quaternary.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.293-298
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• 2015

This study aimed at characterizing the rheological properties and molecular weight of tara gum fractionated with ammonium sulfate. Tara gum was separated into six fractions (F1-F6) at different concentrations of ammonium sulfate, ranging from 12.21 to 28.67% (w/w). The yield of the tara gum fractions ranged between 4.98 and 17.47%, and their intrinsic viscosity ranged from 9.38 to 12.44 dL/g. The highest values of Huggins coefficient (k') and viscosity-molecular mass were observed in fraction F3. The shear viscosity of the tara gum fractions was measured by a cone-plate viscometer, clearly showing shear thinning behavior. Size-exclusion chromatography results showed that the molecular weight ranged between 635.42 and 776.71 kg/mol, and the F3 fraction exhibited higher values of molecular weight.

• Journal of Korean Academy of Nursing
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• v.9 no.2
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• pp.27-38
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• 1979

This study was undertaken to determine the subjective symptoms of fatigue among the house-wives groups. Inquiries into subjective symptoms of fatigue were made by the form designied by the Industrial Fatigue Research Committee of the Japan Society of Industrial Health (1961), Comprising 30 items. These items are classified into 3 groups of 10 items, namely, A) Physical Symptoms, B) Mental Symptoms, C) Neuro-Sensory Symptoms (Figure 1 ). The results of the investigation can be summerized as follows: 1. Within the total items (T), the physical symptoms (A) were the strongest in the effect on the feelings of fatigue, and were followed by (B), and (C). 2. There was a significant difference shown in the distribution of responses by height (X$^2$=236.29, d.f. = 145, p < 0.00001). In the mental category (F = 2.22, d.f. = 4, p = 0.05) and neuro-sensory category (F = 2.64, d.f. = 4, p < 0.001), there was a difference in the responses’com-plaints by weight. 3. As for the ages, housewives at the age of 50 presented a higher rate than those 30 or 20. 4. Regarding the number of children, respondents have more children showed higher frequency rate of complaints. 5. In the investigation sample, complaints were related to education level (f = 18.34, d.f. = 3, p<0.0001) pentruation (t = 2.31, p< 0.022), and sleeping hours (F = 6.04, d.f. = 6, p< 0.0001).

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3317-3320
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• 2012

A novel energetic compound, bifurazano[3,4-b:3',4'-f]furoxano[3'',4''-d] oxacyclohetpatriene (BFFO), was synthesized through special etherification and its structure was determined by single crystal X-ray diffraction. The crystal of $BFFO{\cdot}H_2O$ is monoclinic, space group P2(1)/c with crystal parameters of a = $9.324(4){\AA}$, b = $9.727(4){\AA}$, c = $10.391(4){\AA}$, ${\beta}=106.305(6)^{\circ}$, V = $904.5(6){\AA}^3$, Z = 4, ${\mu}=0.17mm^{-1}$, F(000) = 512 and $D_c=1.866g\;cm^{-3}$. Spectroscopic properties and thermal behaviors of BFFO were studied. BFFO presents good detonation properties.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.11
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• pp.1271-1278
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• 2007

A novel frequency multiplier using composite right/left-handed transmission line is proposed. The left-handed transmission line in the proposed frequency multiplier suppresses the fundamental component($f_0$), while the composite right/left-handed ${\lambda}/4$ open stub diminishes unwanted harmonics. Due to the combination of the left-handed transmission line and composite right/left-handed ${\lambda}/4$ open stub, the only desirable multiplied frequency component such as 3 $f_0$ and 4 $f_0$ are obtained at the output port excellently. For the example of the proposed design, frequency multipliers are designed at 1 GHz of $f_0$ and measured. The measured output power of 3 $f_0$ and 4 $f_0$ is -5.67 dBm and -6.43 dBm, respectively, when the fundamental input power was 0 dBm.

• Bulletin of the Korean Chemical Society
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• v.16 no.7
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• pp.649-653
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• 1995

Solution-state structure of native F430 was determined by using NMR methods and NMR-based distance geometry (DG) computations. Structures were generated with loose NOE-derived interproton distance restraints (2.0-2.5 Å, 2.0-3.5 Å and 2.0-4.5 Å for strong, medium, and weak NOE cross-peak intensities, respectively). 2D NOESY back-calculations of structures were subsequently carried out for establishing the consistence between experimental data and DG-model structures. The back-calculated 2D NOESY spectra of resulting DG structures were well consistent with experimental 2D NOESY spectra. Superposition of 20 independent structures with macrocyclic ring atoms and all atoms of F430 afforded pairwise root mean square deviations (RMSD) of 0.025-0.125 Å and 0.64-1.3 Å, respectively. The macrocyclic rings of structures are well converged to a unique conformation with saddle-shaped deformation whereas most of side chains are not converged. The average dihedral angle (N1-N2-N3-N4, 27.78±1.50°) of 20 DG-structures exhibits that the macrocyclic ring conformation is puckered as much as 12,13-diepimeric F430 (28.75±4.07°).

• Journal of Nutrition and Health
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• v.29 no.5
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• pp.517-527
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• 1996

The food consumption of 148 healthy infants from 4 to 6 months of age have been measured. Three groups were assigned to change of feeding pattern. Formula group(FF, n=102) were fed formula from birth till 6 months of age. Convert 1 group (C1F, n=14) and Convert 2 group (C2F, n=32) were fed breast milk and mixed milk at 2months of age afterthat switched to formula milk, respectively. All infants received solids (solid foods) from 4 months of age. No significant difference was found in the intake of nutrients among three feeding groups excluding carbohydrate intake of C1F-female at 4 months of age. No significant difference was found in the intake of nutrients among three feeding groups excluding carbohydrate intake of C1F-female at 4 months of age. The FF-female(70.9g/d) and C2F-female(66.9g/d) had significantly higher carbohydrate intake when compared to the C1F-female (54.3g/d). The average total energy intake at 4, 6 months were 648.3 and 709.7kcal/d among all infants. At 4 and 6 months of age, mean intake of nutrients was as follows. Calcium intake was 526.7mg/d and 760.0mg/d at 4 and 6 months of age respectively. Iron intake was 8.3mg/d and 10/5mg/d at 4 and 6 months of age respectively. Calories from solids provided 22.5% of total energy intake at 4 months of age, and nearly 32% at 6 months of age. The average energy and protein intakes of all infants were less than the RDA for calcium and iron at 4, 6 months of age.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.449-454
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• 1985

In order to search for the semi-dwarf japonica varieties allelic to the semi-dwarf rice cultivar which is controlled by d-t gene, seven dwarf japonica varieties. Reimei, Hoyoku. Shiranui, Kokumasari, M 7. S.224 and S.295 were crossed to the semi-dwarf cultivar, wx 817. wx 817 is known to have semi-dwarf gene d-t. Their F$_1$, F$_2$ and F$_3$ were grown in 1984 and 1985 and culm lengths were measured at harvest. The results are summarized as follows. 1. The F$_2$s of all 7 cross combinations showed normal distribution and no segregation. 2. The range of culm length variation in the F$_3$ was variable depending on the cross combination, but the general pattern was similar in the all 7 crosses. 3. The mean of F$_3$ and parental F$_2$ mean which were selected into short, medium and tall groups were similar and showed no segregation, implying the selection efficiency in F$_2$. 4. From the results of F$_2$ and F$_3$ segregations, it is concluded that the culm length of the 7 semi-dwarf japonicas tested here are controlled by the same major gene d-t although they are modified by different minor genes.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.3
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• pp.130-134
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• 2009

A new long persistent phosphors of $CaZrO_3$ was synthesized at high temperature with weak reduction atmosphere by a traditional solid state reaction method. Photoluminescence spectra analysis showed that the $CaZrO_3$ doped with $Tb^{3+}$ emitted green-yellow emission caused by the energy level transition from the $^5D_3$ and $^5D_4$ to $^7F_1{\sim}^7F_6$. The main emission spectra of 542 nm peak by the $^5D_4{\rightarrow}^7F_5$ transition was revealed through synthesizing at high temperature in $N_2$ gas atmosphere. The afterglow emission spectra of $CaZrO_3:Tb^{3+}$ long persistent phosphores arise at 546 nm peak of narrow range. After the 254 nm ultraviolet light excitation source was switched off, the green-yellow long persistent phosphor can be observed which could last for 8 h in the limit of light perception of dark-adapted human eyes ($0.32\;mcd/m^2$).