• Food Science and Preservation
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• v.9 no.4
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• pp.418-424
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• 2002

This study was undertaken to develop the optimum baking formular and process in making the improved soy-wheat composite breads furtified with soy flour, which has been known for a source of biologically active phytochemicals and for more vegetable proteins as well. The effects of the addition of soy flour on a rheological properties of dough, on the sensory characteristics of breads, and on the possibilities of commercialization of these functional breads were investigated. As the added amount of soy flour increased, water absorption, development time and the weakness value of dough were increased, but dough stability were decreased in the farinograph. In the extensograph, the more soy flour was added, the less the extensibility and the resistance to extention were shown. As the amount of soy flour increased, gelatinazation point was increased in the amylograph, but the maxium viscosity was decreased. As the added amount of soy flour was increased, b value(yellowness) was obviously increased, L value(lightness) was slightly decreased. However, a value(redness) was not nearly changed in the color of cut loaves. In sensory evaluation, the more soy flour was added, the less the external, the internal characteristics and the eating qualities were shown. Accorting to the addition of soy flour, the toughness and the brittleness tended to be increased proportionally. The dough of 10% soy-wheat composite flour(SF10) was the most favorable on the baking performance.

• Journal of dental hygiene science
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• v.10 no.5
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• pp.373-378
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• 2010

To test the effects of representative fluoride vanishes-1.23% APF gel and 5% NaF Fluoride Varnish-on the surface structure of pit and fissure sealant, this study classified samples of pit and fissure sealant into five groups: Group I deposited in distilled water for ten minutes, Group II treated with APF gel for one minute, Group III treated with APF gel for four minutes, Group IV treated with Fluoride Varnish for one minute, and Group V treated with Fluoride Varnish for four minutes. An abrasion test was carried out to measure changes in weight, along with observation of the surface structure by using an optical microscope, consequently drawing the following conclusions. 1. The results of the abrasion test using pit and fissure sealant, Concise, showed that Group III had the reduction in weight more increased than Group I and that Group V had less reduction in weight (p<0.05); the results of the abrasion test using Eco-S showed Group III had the reduction in weight more increased than Group I and that Group V had less reduction in weight (p<0.05). 2. The results of observation using an optical microscope showed that application of APF gel made the filler remarkable due to loss of substrate and that Group III treated with APF gel for four minutes had the toughest surface, followed by Group II treated with APF gel for one minute, Group I deposited in distilled water for ten minutes, Group IV treated with Fluoride Varnish for one minute, and Group V treated with Fluoride Varnish for four minutes.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.11
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• pp.83-94
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• 2003

In this paper. a highly linear and low glitch CMOS current mode digital-to-analog converter (DAC) by self calibration bias circuit is proposed. The architecture of the DAC is based on a current steering 6＋4 segmented type and new switching scheme for the current cell matrix, which reduced non-linearity error and graded error. In order to achieve a high performance DAC . novel current cell with a low spurious deglitching circuit and a new inverse thermometer decoder are proposed. The prototype DAC was implemented in a 0.35${\mu}{\textrm}{m}$ n-well CMOS technology. Experimental result show that SFDR is 60 ㏈ when sampling frequency is 32MHz and DAC output frequency is 7.92MHz. The DAC dissipates 46 mW at a 3.3 Volt single power supply and occupies a chip area of 1350${\mu}{\textrm}{m}$ ${\times}$750${\mu}{\textrm}{m}$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.9
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• pp.71-80
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• 2007

This paper presents a new push-push VCO technique that extracts a second harmonic output signal from a capacitive commonnode in a negativegm oscillator topology. The generation of the $2^{nd}$ harmonics is accounted for by the nonlinear current-voltage characteristic of the emitter-base junction diode causing; 1) significant voltage clipping and 2) different rising and falling time during the switching operation of core transistors. Comparative investigations show the technique is more power efficient in the high-frequency region that a conventional push-push technique using an emitter common node. Prototype 12GHz and 17GHz MMIC VCO were realized in GaInP/GaAs HBT technology. They have shown nominal output power of -4.3dBm and -5dBm, phase noise of -108 dBc/Hz and -110.4 dBc/Hz at 1MHz offset, respectively. The phase noise results are also equivalent to a VCO figure-of-merit of -175.8 dBc/Hz and -184.3 dBc/Hz, while dissipate 25.68mW(10.7mA/2.4V) and 13.14mW(4.38mA/3.0V), respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.105-112
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• 2010

Applications of plant residues and green manures generally improve the properties of soil under conventional farming system. Therefore, we investigated the improvement of selected soil physical properties, bulk density, porosity, and water content, soil penetration resistance, and soil microbial biomass carbon (SMBC) content as affected by different management practices: 1) conventional tillage without rice straw or green manure crop treatment (TNT, check plot), 2) no-tillage amended with rice straw (NTRS), 3) no-tillage amended with rye (NTR), 4) no-tillage amended with Chinese milk vetch (NTCMV), 5) no-tillage without rice straw or green manure crop treatment (NTNT), The values of bulk density, porosity, and water content ranged from 1.22 to 1.37 Mg $m^3$, from 48.3 to 54.0%, and from 35.0 to 40.2%, respectively. The management practices might positively influence the changes in the selected soil properties, especially in the second experimental year. The soil penetration resistance and SMBC content were also improved after applying rice straw and green manure crops as comparing with TNT. Therefore, applications of the rice straw and green manure crop management practices under no-tillage system positively influenced soil physical properties and soil microbial activities in paddy field.

• Korean Journal of Agricultural Science
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• v.19 no.2
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• pp.161-169
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• 1992

Studies were conducted to examine the effects of single or combined treatment of uniconazole [(E)-1-(4-chlorophenyl)-4, 4-dimethyl 2(1, 2,-4-triazol-1-yl)-1-penten-3-ol)] and silver thiosulfate (STS) on reducing ozone injury to snap beans (Phaseolus vulgaris L. 'Strike'). Two weeks after seeding, plants were given a soil drench of uniconazole(XE-1019) solution at concentrations of 0.001, 0.005 and 0.025 mg/pot, and then two days prior to ozone fumigation, 0.3 and 0.6 mM STS containing 0.01% Tween-20 were also sprayed. Uniconazole was effective in providing protection against ozone injury through increase activities of free radical scavengers such as superoxide dismutase (SOD) and peroxidase (POD) as well as the increase of chlorophyll content and stomatal resistance resulted from plant growth retardation. The phytoprotective effects of STS seemed to be related to its properly of blocking the ethylene action and increasing activities of SOD and POD. Even at low concentrations, a combined treatment with uniconazole drench, STS spray significantly reduced ozone injury compared to single application.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.4
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• pp.525-535
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• 1999

In this study, a new method of fabricated concrete deck bridge construction is proposed. This paper details the method in which concrete multi-girders and fabricated concrete decks are rested on the upper flange of the girder and the female to female type sheat-key is formed to connect girder and deck. The finite element analysis is performed to verify the accuracy of the structural behaviors of the fabricated concrete deck bridge by comparing with experimental results. The first task performed is the analysis of the equilibrium of the member force occurring between the deck and the girder. After verifying equilibrium of the member force determined by the finite element analysis, this process is applied to the analysis of maximum member force as the position of design load. This task is utilized to determine the safety of each member according to the same scale finite element model. The final process in this study is to compare the deflection of girders used in experiment with that of the same scale finite element model to verify the strength of fabricated cincrete deck bridge. By this comparison, it is shown that the behavior of the fabricated concrete deck bridge is almost same as the finite element analysis. The second task is to analyze the load distribution effect according to the number of diaphragms and the composite effect due to the cinnection of the deck and girder by the finite element analysis. From the results of second task, it is found that the load distribution effect is not related to the number of diaphragms in case of the central loading, but is related to the number of diaphragms for eccentric loading. Analysis of the load distribution indicates that the effective number of diaphragm is three. It is also shown that the maximum deflection is decreased to almost one half due to the composite action of the deck and girder.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.413-426
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• 2005

수직 치근파절은 특이성을 나타내지 않기 때문에 치과의사가 정확한 진단을 하기 어렵다. 따라서 수직 치근파절의 임상적 특징, 진단적 증상을 파악하여 향후 근관치료된 치아나 치료되지 않은 치아에서 수직 치근파절의 유발인자와의 관련성 및 고찰을 통해 수직 치근파절의 예방 및 치료에 응용할 수 있을 것으로 생각된다. 연구대상은 조선대학교 부속치과병원 치주과에 내원한 환자 중 최근 2년간 144명의 환자에서 근관치료를 받았거나 받지 않았던 치아 중 임상적 및 방사선학적으로 수직 치근파절로 진단된 156개의 증례를 대상으로 하였다. 모든 불확실한 증례에서 수직 지근파절의 최종 진단은 외과적 탐지를 통해 이루어졌고, 금이 간 치아와 관련될 수 있는 치근파절의 증례의 경우는 제외되었다. 근관치료된 치아와 치료되지 않은 치아, 환자의 나이와 성별, 치아종류 및 파절된 치근부위, 자각증상의 유무를 기준으로 각각의 수치와 백분율로 분류하였다. 수직 치근파절의 증상과 증후별로 분류하였으며, 진단방법에 의한 분류, 치료방법에 따른 분류, 근관 치료 후 수직 치근파절이 발생한 기간에 따른 분류를 시행하고 통계분석을 하여 다음과 같은 결과를 얻었다. 1. 근관치료를 받지 않았던 치아의 수직 치근파절의 발생율은 58%였다. 2. 성별에 따른 발생률에 있어서 남성의 호발양상을 나타내었다. 3. 근관치료된 치아에 있어서 치료되지 않은 치아에 비해 호발연령이 낮았다. 4. 전치부의 수직 치근파절은 관찰되지 않았으며 특히, 강한 교합력을 필요로 히는 구치부에서의 높은 발생율을 나타냈다. 5. 수직 치근파절의 가장 주된 증상 및 증후는 깊은 치주낭 깊이였다. 6. 근관 치료 후 수직 치근파절이 발생한 기간은 평균 5.7년이었다. 7. 다수 증례에 있어서 3개 이하의 결손치를 가졌고, 자각증상이 나타났다. 이상의 결괴에서 한국인에 있어서 근관치료를 받지 않은 치아의 수직 치근파절은 드문 현상이 아님을 알 수 있었고 남성과 구치부에 있어서의 높은 발생율을 알 수 있었다. 그 이유로는 강한 교합력, 딱딱한 음식의 저작습관, 치조골 흡수에 따른 낮은 저항성, 골 유연성의 저하 등으로 여겨진다. 그러나, 수직 치근파절은 아직까지 정확한 진단을 내리기는 여전히 어려운 상태이며, 이를 위한 다양한 진단방법 및 더 나은 연구가 필수적이라 하겠다. 그리고, 향후 보다 많은 증례에 대한 분석, 치주질환에 이환되지 않은 경우의 분석, 치료 후 생존 기간에 대한 고찰 등도 필요하리라 사료된다.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.135-142
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• 1989

Methyl tert-butyl ether(MTBE) was synthesized from vapor phase reaction of methanol with iso-butylene over HZSM-5 catalysts, and effects of SiO$_2/Al_2O_3$ ratio in the HZSM-5 catalysts and reaction conditions on products distribution have been examined. Acid strength and acid type of each catalyst with different SiO$_2/Al_2O_3$ ratio were measured using pyridine adsorption followed by temperature programmed desorption(TPD) and IR analysis. Reactants and products adsorption characteristics on different acid sites have also been examined. As the SiO$_2/Al_2O_3$ ratio of HZSM-5 catalyst was increased, selectivity to MTBE was improved as a result of decrease in dimethylether(DME) formation at the strong acid sites. Conversion and selectivity to MTBE were also greatly enhanced as $i-C_4H_8/CH_3OH$ reactant ratio was increased, and overall about 80$^{\circ}$C was adequate for the MTBE synthesis. The properties of deposited coke on spent catalysts were examined by TG, DTA and IR spectrum analysis, indicating the amount of the coke deposit in the order of HY > H-Mordenite > HZSM-5. Even if the coke deposited on H-Mordenite was little more in amount than to that on HZSM-5, the former deactivated quickly due to its non-interconnected channel structure. For HY, owing to its lange pore size, significant $i-C_4H_8$ polymerization was occured, and rapid deactivation and severe coke formation has resulted within few hours.

• Geophysics and Geophysical Exploration
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• v.5 no.4
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• pp.309-315
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• 2002

Conventional electromagnetic (EM) method using small loops as a source and receiver has been used in detection of conductive buried objects like a metal detector or in qualitative estimation of the subsurface conductivity variation. Recently, however, since detection of buried objects and imaging of the subsurface conductivity distribution in a relatively conductive area are in a high demand for environmental and engineering purposes, the quantitative interpretation technique of EM data is actively studied. In this regard, we introduce a brief principle of EM survey and show an example of the detection of buried conductive material and imaging of the subsurface conductivity distribution based on data measured at a test survey area. Through this study, we show that multi-frequency EM surveys using small loops may be a good solution to give quick and detail information of subsurface in a conductive survey area.