• Journal of the Institute of Convergence Signal Processing
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• v.1 no.1
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• pp.89-96
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• 2000

In this paper, we propose a vision algorithm for the inspection of very small RF-chip inductor which is used in mobile-communication terminal. The proposed method divides coil part from the inductor body by local adaptive thresholding and integral projection method. After dividing work, the coil components are extracted by thinning and labelling techniques. The test items are the number of turns, the intervals in coil, and the measure of uniformity between the extracted lines. If the values of these are more than the specific value a tested product is decided bad one. In the simulation, the proposed method has a good performance.

• Journal of Applied Reliability
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• v.13 no.2
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• pp.109-116
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• 2013

The solder is any of various fusible alloys, usually tin and lead, used to join metallic parts that provide the contact between the chip package and the printed circuit board. Solder plays an important role of electrical signals to communicate between the two components. In this study, two kinds of Ag-free solder as sample is made to conduct the thermal shock test and the high humidity temperature test. Low resistance is measured to estimate crack size of solder, using daisy chain. The low speed shear test is also performed to analyze strength of solder. The appropriate degradation model is estimated using the result data. Depending on the composition of solder, lifetime estimation is conducted by adopted degradation model. The lifetime estimated two kinds of Ag-free solder is compared with expected lifetime of Sn-Ag-Cu solder. The result is that both Ag-free composition are more reliable than Sn-Ag-Cu solder.

• Polymer(Korea)
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• v.25 no.4
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• pp.528-535
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• 2001

Polyurethane specimens were mainly composed of polyol, MDI, silicone surfactant, and water. The effects of ethylene glycol on the cell size, forming magnification, cream time, gel time, take free time, final free rising height, and reactive temperature were investigated. The cyclopentane was used for PU foam as a physical blowing agent. The components were hand-mixed at about 5000 rpm within 4 seconds at room temperature. The mixtures with various ethylene glycol contents were foamed in the wood mold. When the index of isocyanate was fixed, as the amount of ethylene glycol increased, cell size and thermal conductivity were decreased by about 5.1% and 14%, respectively.

• Food Science of Animal Resources
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• v.39 no.6
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• pp.1015-1020
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• 2019

Staphylococcus aureus is a representative pathogenic bacterium carefully controlled in the dairy industry because it causes bovine mastitis and thus, can enter the dairy chain. Furthermore, the emergence of multi-drug resistant S. aureus is a big problem. We previously isolated a Lactococcus lactis strain producing a bacteriocin that exhibited strong antimicrobial activity against S. aureus. In this study, we investigated the synergistic inhibition of S. aureus by the bacteriocin and a bacteriophage (SAP84) which is specific to the organism. The bacteriocin (12.5-100 AU/mL) inhibited the growth of S. aureus KCTC 3881 in a dose-dependent manner, as did the bacteriophage SAP84 (0.001-1 MOI; multiplicity of infection). Co-treatment with the bacteriocin (100 AU/mL) and the bacteriophage (0.1 MOI) significantly inhibited the growth of S. aureus compared to each treatment alone (bacteriocin or bacteriophage), indicating the two components showed synergistic inhibition of S. aureus. Therefore, the bacteriocin and bacteriophage combination can be used as a good strategy for controlling pathogenic bacteria.

• Korean Journal of Food Science and Technology
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• v.4 no.3
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• pp.213-223
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• 1972

This paper chose the methods of methylesterification of the use of methoxide, the mixture solution of methanol-benzen-sulfuric acid in transesterification of the fat in cow's milk and modified powder milk and separated by gas liquid chromatography with F.F.A.P., D.E.G.A. as liquid phase. Quantitative analysis of the fatty acid of milk fat in cow's milk and modified powder milk was determined by gas liquid chromatography using the method of temperature programming which should be used to obtain satisfactory separation of short chain fatty acid on the chromatogram. It was found that the fatty acid composition of cow's milk and modified powder milk are all the major fatty acid of milk fat obtained by GLC analysis. Main components was found to be from butyric acid to arachidonic acid showing Fig. 3, 4, 5 and Table 4, 5, 6, 7, 8, 9.

• Journal of the Optical Society of Korea
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• v.6 no.3
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• pp.121-127
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• 2002

The operating principal of a ring laser gyroscope depends on the phase difference for the counter-propagating waves within a closed path. The reflecting mirrors mounted on the monoblock form the traveling waves. The manufacturing accuracy of the monoblock influences the traveling path of ray, the sensitivity of laser resonator for misalignments, and diffraction losses. A 3 $\times$ 3 ray transfer matrix was derived for optical components with centering and squaring errors in a ring resonator. The matrix can be utilized to predict the optical ray paths on the basis of the manufacturing errors of the monoblock as well as the misalignment of mirrors. Then the distance and orientation (o. slope) at the arbitrary plane inside the resonator along the ideal optical path can be calculated from the chain multiplication of the ray transfer matrix for each optical component in one round trip. We also show that the counter-propagating rays In a ring resonator with errors does not coincide in each round trip, which results in gain difference between two beams, and how these errors can be adjusted through the alignment procedure. Finally this 3 $\times$ 3 ray matrix formalism can be used to calculate the beam size and its displacement from the optical axis and the deviation at the diaphragm.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.70-79
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• 1998

This study was conducted to understand the effects of weather and tapping date on yield and quality of lactree(Rhus verniciflua) sap yield showed a significant positive correlation with the minimum temperature of one day before sap collection at 1% level and with theminimum humidity of theday of sap collection at 5% level. However, the differences between the maximum and the minimum temperatures and humidities of the day of sap collection were negatively correlated with the sap yield at 5% level. Multiple regression analysis indicated that the minimum temperature of one day bofore sap collection and the minumum humidity of the day sap collection were important factors for increasing sap yield. The high sap yield of lactree by Japanese tapping method was recorded during mid-July and early August. Seasonal variation in lactree sap constituents was observed. The sap collected on 15th of August contained the highest urushiol content (68.3%) and the lowest water content resulting in high quality of lactree sap. By reversed-phase HPLC analysis, fove urushiol components were separated from each other depending on the number of doulbe bonds in the side-chain , and seaxonal variation of urushiol composition was noticed. The 3-C15 triene content fo the sap collected on 5th of July was the highest(77.56%) indicating the major component of urushiol which affects lactree sap quality.

• Transactions on Electrical and Electronic Materials
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• v.18 no.4
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• pp.211-216
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• 2017

The dielectric properties of two polyurethanes (PUs) with different hard segments, i.e., aromatic methylene di-p-phenyl diisocyanate (MDI) and aliphatic hexamethylene diisocyanate (HDI), were investigated in the temperature range of -100 to $100^{\circ}C$ and in the frequency range of 1 Hz to 3 kHz. The ${\alpha}$-relaxations induced by the glass transition of the equivalent soft segments in the two PUs occurred at relaxation times of ${\tau}=3.46{\times}10^{-3}s$ for MDI-PU and ${\tau}=3.39{\times}10^{-2}s$ for HDI-PU at $-20^{\circ}C$, in accord with the temperature-frequency superposition principle, resulting in similar shifting factors. However, different I-relaxations were observed for the two PUs. The I-relaxation of MDI-PU occurred due to the mobility of the chain extenders near $80^{\circ}C$ with a slower shifting rate than the ${\alpha}$-relaxation. On the other hand, I-relaxation arising from both the extender and the unconstrained hard segments of HDI-PU occurred at $70{\sim}100^{\circ}C$, indicating complicated dielectric behavior due to partial interaction with the ${\alpha}$-relaxation at high frequencies. Thus, the I-relaxation of HDI-PU did not follow the superposition principle. The dielectric behaviors of the PUs were mainly influenced by their phase transitions, which were affected by the structure and components of the materials.

• Korean Journal of Pharmacognosy
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• v.24 no.4
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• pp.282-288
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• 1993

Very little utilization of the fruits of Malus baccata(Rosaceae) has been employed for food and medicinal plants except for preparing fruit beverages. But, it was estimated as valuable to investigate the chemical components for the botanical resource of this plant. In this study, it was found that the fruits of this plant contained primary long chain alcohol, ${\beta}-sitosterol$, campesterol, ursolic acid and ${\beta}-_D-glucosides$ of ${\beta}-sitosterol$ and campesterol. However, phloretin(dihydrochalcone) and its 5-O-glucoside(phloridzin) known as plant growth regulators in many Rosaceae plants were not found in this plant material by co-TLC analysis with authentic specimens. Although plant sex hormone, estrone, was often contained in relates of M. baccata, e.g., Prunus spp., Crataegus spp. and Malus spp., this compound was not detected in this fruit by comparison with an authentic material. By RIC chromatography, it was suggested that the Soxhlet extraction by the solvent of ether was excellently useful to extract ursolic acid efficiently.

• Macromolecular Research
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• v.17 no.3
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• pp.156-162
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• 2009

Supramolecular hydrogels were instantaneously fabricated by mixing aqueous solutions of $\alpha$-cyclodextrins ($\alpha$-CDs) and amphiphilic methoxy (polyethylene glycol) (MPEG)-$\varepsilon$-caprolactone (CL) oligomer, which was synthesized via the ring-opening polymerization of the CL monomer using low-molecular-weight MPEG ($M_n$ of MPEG=2,000 g/mol) as an initiator. The supramolecular structure of the hydrogels was revealed by X-ray diffraction (XRD) analyses. Rheological studies of the hydrogels revealed an elastic character when the number of CL units in the oligomer was more than 2, and the obtained hydrogels showed high storage modulus but relatively low shearing viscosity due to the low-molecular-weight character of the oligomer, which was more preferable for use as an injectable delivery system. The physical properties of the hydrogels could be modulated by controlling the chain morphology and concentration of the oligomers, as well as the feed molar ratio of the oligomer to $\alpha$-CD. The components of the supramolecular hydrogels are biocompatible and can readily be eliminated from the body. These features render the supramolecular hydro gels suitable as drug delivery systems and tissue engineering scaffolds.