• Journal of Ginseng Research
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• 제6권2호
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• pp.131-137
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• 1982

The effect of red ginseng residue on the several enzyme activities of the koji and alcohol fermentation were investigated. The koji showed maximum values of amylase and cellulase activity when it was prepared by 30% red ginseng residue and 70% wheat bran, and of protease activity when it was prepared by 40% red ginseng residue and 60% wheat bran-${\alpha}$ amylase activity of the koji during its fermentation was increased rapidly until 4 days and there after it was increased slowly, but ${\beta}$-amylase was rapidly increased after 3 days fermentation. During the preparation of the koji, the acidic, neutral protease and cellulase activities showed the maximum value after 3 days fermentation and the alkaline protease showed the maximum value within 4-6 days fermentation. On the otherhand, fermented broth, containing 6%(v/v) alcohol, could be obtained when the substrate was saccharified by the koji, based on 25% red ginseng residue and 75% wheat bran, prior to alcohol fermentation.

• 한국기계가공학회지
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• 제8권3호
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• pp.33-37
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• 2009

Manifold could apply stainless steel with light weight and durability to improve fuel efficiency at automotive industry. This study is analyzed and compared by heat transfer and deformation according to the materials of cast iron and stainless steel. The heat transfer at manifold of cast iron at the distribution of heat temperature is more than that of stainless steel. But the value of maximum heat deformation in case of stainless steel is 1.5 times as great as that in case of cast iron. The value of maximum heat equivalent stress in case of stainless steel is 2.7 times as great as that in case of cast iron. This maximum stress at manifold is shown at the part assembled with engine body.

• 한국정밀공학회지
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• 제12권6호
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• pp.112-119
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• 1995

Early fracture and cutting force of ceramic tool for hardened STC3 steel was investigated in this study. It was found that early fracture of ceramic tool was mostly occurred before normal wear was progressed beyond a critical cutting speed and normal wear was performed under the critical cutting speed. The relationships among critical cutting speed, which was a cause of early fracture, suggested cutting cross section, that is, maximum thickness of cut and width of cut, and cutting force were examined. The following conclusions were obtained: (1)Critical cutting speed showed a high value in the case of small maximum thickness of cut and large nose radius, but was not influenced by width of cut, (2)Principal, feed and radial force, respectively, showed the proportional value to constant cutting area, width of cut and maximum thickness of cut orderly, (3)Occurrence of early fracture was dependent upon radial force.

• Steel and Composite Structures
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• 제22권4호
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• pp.855-874
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• 2016

In this paper, it is aimed to evaluate the earthquake angle influence on the seismic performance of steel highway bridges. Upper-deck steel highway bridge, which has arch type load bearing system with a total length of 216 m, has been selected as an application and analyzed using finite element methods. The bridge is subjected to 1992 Erzincan earthquake ground motion components in nineteen directions whose values range between 0 to 90 degrees, with an increment of 5 degrees. The seismic weight is calculated using full dead load plus 30% of live load. The variation of maximum displacements in each directions and internal forces such as axial forces, shear forces and bending moments for bridge arch and deck are attained to determine the earthquake angle influence on the seismic performance. The results show that angle of seismic input motion considerably influences the response of the bridge. It is seen that maximum arch displacements are obtained at X, Y and Z direction for $0^{\circ}$, $65^{\circ}$ and $5^{\circ}$, respectively. The results are changed considerably with the different earthquake angle. The maximum differences are calculated as 57.06%, 114.4% and 55.71% for X, Y and Z directions, respectively. The maximum axial forces, shear forces and bending moments are obtained for bridge arch at $90^{\circ}$, $5^{\circ}$ and $0^{\circ}$, respectively. The maximum differences are calculated as 49.12%, 37.37% and 51.50%, respectively. The maximum shear forces and bending moments are obtained for bridge deck at $0^{\circ}$. The maximum differences are calculated as 49.67%, and 49.15%, respectively. It is seen from the study that the variation of earthquake angle effect the structural performance of highway bridges considerably. But, there is not any specific earthquake angle of incidence for each structures or members which increases the value of internal forces of all structural members together. Each member gets its maximum value of in a specific angle of incidence.

• 한국통신학회논문지
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• 제18권12호
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• pp.1797-1805
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• 1993

이 논문에서는 DS/SS(Direct Sequence Spread/Spectrum) 시스템에서 초기동기(aquisition)를 위해, 정합 필터의 출력중 부정합된 최대 상관값을 임계값(threshold)으로 결정하는 TDMMC(Threshold Decision from the Maximum Mismatching Correlation value) 알고리듬을 제안한다. PN코드는 주기성과 정합됐을 때의 상관값이 정합되지 않을 때의 상관값보다 크다는 성질을 가지고 있다. 기존의 방식은 위의 2가지 성질 중에서 후자에 기반을 두고 있는 반면, TDMMC는 위의 성질 둘 모두에 기반을 두고 있다. TDMMC의 궁극적인 목적은 수신기에서 신호 검파확률를 1에 가깝게 하는데 있다(Pd$\longrightarrow$1). TDMMC는 임계값 블록(threshold block)을 이용하여 S/N이 변함에 따라 적절한 임계값을 설정할 수 있다. 시뮬레이션 결과, 비동기식 DS/SS-CSK 시스템에 적용된 TDMMC는 기존의 방식에 비해 성능이 향상됨을 보여준다.

• 한국연초학회지
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• 제5권2호
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• pp.17-24
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• 1983

Varietal difference of crop stand, growth of each organs and the factors of dry matter Production at different growth stage of three local tobacco varieties (Hyangcho, Youngwolyub and Yonginyub) were investigated in 1979 and 1980. Varietal variation of total standing crops was clear from 45th day after transplanting to end maximum value of photosyntheticinon-photosynthetic organs was Hyangcho: 1.9, Youngwolyub; 1.6, Yonginyub; 2.3. Maximum value of L/S and T/R ratio was clear from 35th day after transplanting to 45th day. RGR, NAR and CGR were in decreasing order of Yonginyub) Youngwolyub)Hyangcho through out growth stage, LAR and SLA were in decreasing from early growth stage to last growth stage, LAI was obtained to maximum value in the large growth state and LAI was increasing order of during the total growth period that it was Hyangcho is 7.6. Youngwolyub is 9.1 and Yonginyub is 8.7, SLA was Hyangcho;$2.088\textrm{cm}^2$/g/leaf, Youngwclyub;$2.173\textrm{cm}^2$/g/leaf and Yonginyub;$2.020\textrm{cm}^2$/g/leaf, respectively.

• International Journal of Concrete Structures and Materials
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• 제18권3E호
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• pp.213-219
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• 2006

Modified singular fracture process zone(S-FPZ) model is proposed in this paper to determine a fracture criterion for continuous crack propagation in concrete. The investigated fracture properties of the proposed fracture model are strain energy release rate at a micro-crack tip and the relationship between crack closure stress(CCS) and crack opening displacement(COD) in the FPZ. The proposed model can simulate the actual fracture energy of experimental results fairly well. The results of the experimental data analysis show that specimen geometry and loading condition did not affect the CCS-COD relation. However, the strain energy release rate is a function of not only specimen geometry but also crack extension. The strain energy release rate remained constantly at the minimum value up to the crack extension of 25 mm, and then it increased linearly to the maximum value. The maximum fracture criterion occurred at the peak load for specimens of large size. The fracture criterion remained at the maximum value after the peak load. The variation of the fracture criterion is caused by micro-cracking and micro-crack localization. The fracture criterion of strain energy release rate can simply be the size effect of concrete fracture, and it can be used to quantify the micro-cracking and micro-crack localizing behavior of concrete.

• 한국전기전자재료학회논문지
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• 제17권5호
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• pp.492-496
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• 2004

In this study, (0.96 －x)(PSN-PZT)－xBF－0.04 PNW＋0.3wt%MnO$_2$＋0.6wt%CuO ceramics were fabricated with the variations of the amount of BiFeO$_3$substitution and sintering temperature for the development of modified ceramics which can be sintered in the low temperature($\leq$100$0^{\circ}C$ ), and their microstructural, dielectric and piezoelectric characteristics were investigated. As the amount of BiFeO$_3$ substitution was increased, the density, mechanical quality factor(Q$_{m}$) and electromechanical coupling factor(k$_{p}$) showed the maximum value at each of sintering temperature. At sintering temperature of 98$0^{\circ}C$ and BiFeO$_3$substitution of 2 mol%, the density, dielectric constant and electromechanical coupling factor(k$_{p}$) showed the maximum value of 7.84 g/㎤, 1415 and 0.49, respectively. And at sintering temperature of 95$0^{\circ}C$ and BiFeO$_3$substitution of 3mol%, mechanical quality factor showed the maximum value of 1062. 1062.

• 한국농공학회논문집
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• 제46권6호
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• pp.3-10
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• 2004

The fundamental study of hydrologic redesign of Donghwa area located in a sccond tributary of Seomjin river was performed. The amounts of hydrologic design were estimated using the available cumulated hydrology data provided by Korea Agricultural and Rural Infrastructure Corporation (KARICO). The management status of The water resources in Donghwa area was also widely surveyed. The probability rainfalls, probable maximum precipitation (PMP) and probability floods were estimated and subsequently their changes analyzed. The amount of 200 year frequency rainfall with l day duration was 351.1 mm, 2.5 % increased from the original design value, and The PMP was 780.2 mm. The concentration time was reestimated as 2.5 hours from existing 2.4 hours. Soil Conservation Service(SCS) method was used to estimate effective rainfall- The runoff curve number was changed from 90 to 78, therefore the maximum potential retention was 71.6 mm, 154 % increased from the original value. The Hood estimates using SCS unit hydrograph showed 8 % increase from original value 623 $m^3$/s to 674 $m^3$/s and The probable maximum Hood was 1,637 $m^3$/s. Although the Row rate at the dam site was increased, the Hood risk at the downstream river was decreased by the Hood control of the Donghwa dam.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.419-422
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• 2000

This paper was to measure the structure, piezoelectric properties of 0.05Pb($A1_{0.5}$$Nb_{0.5}$)-0.95Pb($Zr_{0.52}$$Ti_{0.48}$)$O_3$ ceramics dopped with additive after creating the specimens with a general method. It is shown that X-ray diffraction pattern variation of lines (200) have tendency to move in simple peak by addition of additive. According to the increase of $Cr_2$$O_3$, tetragonality hardly have variation, according to the increase of $Fe_2$$O_3$, tetragonality decreased on the whole. According to dopping with $Cr_2$$O_3$ and $Fe_2$$O_3$, electromechanical factor(kp) largely increased, in case of sintering at $1200^{\circ}C$ kp was maximum value of 40.04[%] at $Cr_2$$O_3$ 0.3wt%, and maximum value of kp 42.9 [%] at $Fe_2$$O_3$, 0.9wt%. In case of sintering at 120$0^{\circ}C$, mechanical duality factor(Qm) was maximum value of Qm 268.8 at $Cr_2$$O_3$, 0.9 wt%.