• Journal of Sensor Science and Technology
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• v.4 no.3
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• pp.22-29
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• 1995

Lithium ionic solid electrolyte was synthesized at $60^{\circ}C$ in $N_{2}$ ambience by sol-gel method, using tetraethyl orthosilcate, lithium methoxide, zirconium n-propoxide, and tributyle phosphate as precursors. The prepared material was dried and crushed into powder, and it was pressed into disk type samples. These samples were sintered at $900^{\circ}C{\sim}1100^{\circ}C$ for 50 hours. The physical characteristics of the samples were investigated by TG/DTA, SEM, AES and XRD methods. $CO_{2}$ sensor based on lithium ionic solid electrolyte was fabricated and its operational characteristics were measured. The sensing characteristics of the sensor sintered at $1000^{\circ}C$ shows the variation of e.m.f. about $35{\sim}63\;mV/decade$ for the variation of $CO_{2}$ concentration at $200^{\circ}C{\sim}300^{\circ}C$ of operating temperature, and good linearity for $300{\sim}6000\;ppm$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1261-1266
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• 2009

In this paper, triple band mobile chip antenna for DCS(1.71${\sim}$1.88GHz) / PCS(1.75${\sim}$1.87GHz) / UPCS(1.8S${\sim}$1.99GHz) on PCB Layout is designed. To analyze the characteristics of the designed antenna, we used commerical simulation tool(HFSS). Triple and wide band characteristic could be realized the measured bandwidth(V.S.W.R<2.0) of the designed antenna operated in 1.71GHz${\sim}$1.99GHz. The size of the designed antenna is about 19mm${\times}$4mm${\times}$1.6mm, narrow bandwidth which is a defect of chip antenna is improved. And its experimental results were a good agreement with simulation performance.

• Food Science and Preservation
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• v.16 no.3
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• pp.376-384
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• 2009

Response surface methodology (RSM) was used to monitor the characteristics of ethanol extracts from glasswort (Salicornia herbacea). A central composite design was used to investigate the effects of the independent variables of sample ratio, extraction temperature, and ethanol concentration on the dependent variables color, sugar, salinity, yield, electron donating ability, and total polyphenol content of extracts. The maximum $^{\circ}Brix$ (8.46) was obtained under specific extraction conditions, with a sample ratio of 7.04 g/100 mL, an extraction temperature of $89.01^{\circ}C$, and an ethanol concentration of 34.29% v/v. At a sample ratio, extraction temperature, and ethanol concentration of 7.00 g/100 mL, $89.15^{\circ}C$, and 34.14% v/v, respectively, the salinity was 7.35%. When the sample ratio, extraction temperature, and ethanol concentration were 5.56 g/100 mL, $68.61^{\circ}C$, and 99.14% v/v, respectively, the maximum electron donating ability was 86.10%. A maximized total polyphenol content of 1,140.15 mg/100 g was found with the following conditions: sample ratio of 8.6 g/100 mL, extraction temperature of $64.19^{\circ}C$, and ethanol concentration of 71.74% v/v. Overall, the optimal ranges of extraction conditions for effective components of glasswort were 3.38.5.33 g/100 mL sample ratio, $55.87-76.96^{\circ}C$, and 25.00.67.31% v/v ethanol.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.3 s.357
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• pp.59-64
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• 2007

This paper describes the PLL of TCON(Timing Controller) chip for FPD(Flat Panel Display). We propose a new V-I converter which is insensitive to the power supply variation when it is applied to the TCON. The new V-I converter compensated the output frequency of VCO by appling the current that is inversely proportional to the voltage variation. The proposed idea is implemented with a 1-ploy 3-metal 0.25m TSMC CMOS technology and has the output frequency range from 192MHz to 360MHz at the supply voltage of 2.5V. Measurement result shows the RMS jitter of 100ps in the above output frequency range.

• Transactions of Materials Processing
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• v.24 no.1
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• pp.44-51
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• 2015

The current study seeks to examine the effects of V and C additions on the mechanical and low thermal expansion properties of a high strength invar base alloy. The base alloy (Fe-36%Ni-0.9%Co-2.75%Mo-0.7Cr-0.23Mn-0.17Si-0.3%C, wt.%) contains $Mo_2C$ carbides, which form as the main precipitate. In contrast, alloys with additions of 0.4%V+0.3%C (alloy A) or 0.4%V+0.45%C (alloy B) contain $Mo_2C$+[V, Mo]C carbides. The average thermal expansion coefficients of these high strength invar based alloys were measured in the range of $5.16{\sim}5.43{\mu}m/m{\cdot}^{\circ}C$ for temperatures of $15{\sim}230^{\circ}C$. Moreover, alloy B showed lower thermal expansion coefficient than the other alloys in this temperature range. For the mechanical properties, the [V, Mo]C improved hardness and strengths(Y.S. and T.S.) of the high strength invar base alloy. T.S.(tensile strength) and Y.S.(yield strength) of hot forged alloy B specimen were measured at 844.6MPa and 518.0MPa, respectively. The tensile fractography of alloy B exhibited a ductile transgranular fracture mode and voids were initiated between the [V, Mo]C particles and the matrix. Superior properties of high strength and low thermal expansion coefficient can be obtained by [V, Mo]C precipitation in alloy B with the addition of 0.4%V and 0.45%C.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.585-588
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• 2011

본 논문은 HEVC 표준화 회의 중 빈 단위 병렬화 위해 제안된 V2V 기술을 바탕으로 슬라이스 내에서 적응적으로 발생 확률 예측을 통하여 압축 효율을 높이는 기술을 제안한다. 기존의 V2V 기술은 슬라이스 단위로 확률 양자화 간격과 대표 확률 결정하여 다수개의 빈 코더에 매핑하여 병렬 엔트로피 부호화를 수행하였다. 제안하는 방법은 V2V 기술에서 슬라이스 보다 작은 단위의 확률적 특성을 고려하여 슬라이스 내에서 대표확률의 선택을 적응적으로 결정한다. 대표 확률의 적응적인 선택은 이전의 부호화된 빈의 실제 심볼의 확률을 이용하며, 이로 인해 슬라이스 보다 작은 단위의 국부적 특성을 확률 양자화기에 반영할 수 있다. 실험 결과, 제안하는 방법을 위해 실험된 현재 부호화 빈의 발생확률은 이용하여 최적의 확률을 얻는 실험은 기존의 V2V 기술 대비 0.1%의 부호화 효율을 얻었다.

• The Journal of the Petrological Society of Korea
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• v.20 no.1
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• pp.23-37
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• 2011

The scaling properties on the length distribution of microcrack populations from Tertiary crystalline tuff are investigated. From the distribution charts showing length range with 15 directional angles and five groups(I~V), a systematic variation appears in the mean length with microcrack orientation. The distribution charts are distinguished by the bilaterally symmetrical pattern to nearly N-S direction. The whole domain of the length-cumulative frequency diagram for microcrack populations can be divided into three sections in terms of phases of the distribution of related curves. Especially, the linear middle section of each diagram of five groups represents a power-law distribution. The frequency ratio of linear middle sections of five groups ranges from 46.6% to 67.8%. Meanwhile, the slope of linear middle section of each group shows the order: group V($N60{\sim}90^{\circ}E$, -2.02) > group IV($N20{\sim}60^{\circ}E$, -1.55) > group I($N60{\sim}90^{\circ}W$, -1.48), group II($N10{\sim}60^{\circ}W$, -1.48) > group III($N10^{\circ}W{\sim}N20^{\circ}E$, -1.06). Five sub-populations(five groups) that closely follow the power-law length distribution show a wide range in exponents( -1.06 - -2.02). These differences in exponent among live groups emphasizes the importance of orientation effect. In addition, breaks in slope in the lower parts of the related curves represent the abrupt development of longer lengths, which is reflected in the decrease in the power-law exponent. Especially, such a distribution pattern can be seen from the diagram with $N10{\sim}20^{\circ}E,\;N10{\sim}20^{\circ}W$ and $N60{\sim}70^{\circ}W$ directional angles. These three directional angles correspond with main directions of faults developed around the study area. The distribution chart showing the individual characteristics of the length-cumulative frequency diagrams for 15 directional angles were made. By arraying above diagrams according to the categories of three groups(A, B and C), the differences in length-frequency distributions among these groups can be easily derived. The distribution chart illustrates the importance of analysing microcrack sets separately. From the related chart, the occurrence frequency of shorter microcracks shows the order: group A > group B > group C. These three types of distribution patterns could reveal important information on the processes occurred during microcrack growth.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.516-521
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• 1999

The average sugar content and total acidity (tartaric acid %) in Campbell Early harvested at Youngdong, Chungbuk in 1998 were $11{\sim}16^{\circ}Brix\;and\;0.7{\sim}1.1%$, respectively. Extra sugar should be added to musts to have higher than 12% of alcohol content for red wine fermentation. When extra sugar and active dry yeast were added to Campbell Early must, wine fermentation was ended after 9 days at $25^{\circ}C$. The ethanol content was 14.7% (v/v). However, when sugar was added only without yeast, wine fermentation was ended up at 14. 4% (v/v) of ethanol after 15 days. The total acidity (tartaric acid %) and pH was almost unchanged during both fermentations. Potassium metabisulfite was found to inhibit the propagation of bacteria without affecting red wine fermentation. But when potassium metabisulfite was directly added to young red wine after fermentation, the red color of wine was decolorized to yellow.

• Journal of Food Hygiene and Safety
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• v.21 no.4
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• pp.238-243
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• 2006

The populations of V. parahaemolyticus were enumerated in oysters collected in wholesale seafood markets in Seoul and tested in various possible condition. The populations of oysters soled in the markets were ranged $<2\sim1.4\times10^6$ MPN/100 g from April to November in 2005. In the case of oysters added with V. parahaemolyticus of $4\times10^3$ CFU/100 g, the highest population numbers were $1.4\times10^7$ CFU/100 g, $5.4\times10^5$ CFU/100 g and $2.7\times10^4$ CFU/100 g at $36^{\circ}C$ after culturing for 15 hours, at $25^{\circ}C$ after 15 hours and at $4^{\circ}C$ after 15 hours, respectively. But the difference of the populations of V. parahaemolticus in oysters stored in the icebox with ice for bulked sale and displayed in stalls on ice for the small packaged sale was not significant. In the case of oysters carried with ambient temperature at $30.8^{\circ}C$, the V. parahaemolyticus density was dramatically increased from $2.7\times10^5$ to $1.4\times10^8$ MPN/100 g. It was indicated it is important to carry the oysters to home with ice after purchase. Even after the washing two times with 21 tap water, the common cooking method in Korea was not greately make the decrease of V. parahaemolyticus density from $1.4\times10^8$ MPN/100 g to $9.0\times10^5$ MPN/100 g. So it is noticed to stored in low temperature after cooking, especially in hot seasons.

• Food Science and Preservation
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• v.14 no.1
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• pp.67-72
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• 2007

To prepare useful foods from Acanthopanax koreanum, extraction of major constituents by water and ethanol solutions were investigated Reflux extractions of 300 g of dried material of particle size less than 0.5 cm, were carried out in 7.5 L of water, or ethanol solutions (30 -95% v/v) for 9 hr at $100^{\circ}C$. The pH values of extracted solutions were 4.0-6.5. The Color b-value of extracted solutions increased as ethanol concentrations dropped and with longer extraction times. The amounts of material in extracts increased rapidly in the first 2-3 hr of extraction. The extract levels from 30-70% ethanol solutions were 0.27-0.47 g/100 g. The main free sugars of extract were sucrose, fructose and glucose. Eleutherosides were extracted rapidly (within 3 hr), and eleutheroside extraction was best in water or in 30-70% ethanol 95% ethanol solutions were less effective. The eleutherosides were extracted to 97% by water or 30-70% ethanol solutions after 3-5 hr. Acanthoic acid extraction was more affected by ethanol level than by extraction time water achieved only trace extinction. In summary, reflux extraction in 40-70% ethanol for 3-5 hr was adequate for the extraction of functional materials from Acanthopanax koreanum.