• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.10
• /
• pp.1323-1328
• /
• 2011

In the current design process for the lower arm used in automobile parts, an optimal solution of its various design variables should be found through exploration of the design space approximated using the response surface model formulated with a first- or second-order polynomial equation. In this study, a multi-level computational DOE (design of experiment) was carried out to explore the design space showing nonlinear behavior, in terms of factors such as the total weight and applied stress of the lower arm, where a fractional-factorial orthogonal array based on the artificial neural network model was introduced. In addition, the tolerance robustness of the optimal solution was estimated using a tolerance optimization with six sigma constraints, taking into account the tolerances occurring in the design variables.

• Korean Journal of Environment and Ecology
• /
• v.14 no.3
• /
• pp.199-204
• /
• 2000

최근 자연생태계에서 일어나고 있는 자생 민들레류의 감소와 서양민들레의 급속한 증가원을 종자 발아특성을 통해 알아보고자 한다. 각각의 종자는 무처리를 비롯하여 10일, 20일, 30일, 60일간의 저온처리를 실시하였으며 발아조건은 광조건과 암조건으로 실험하였다. 자생민들레의 경우에 광조건하의 무처리 대조구에서 28%의 발아율을 나타내었으나 60일간의 저온처리구에서 90%의 발아율을 나타내었다. 발아세와 평균발아기간도 30일 이상의 저온처리와 광조건하에서 양호한 성적을 나타내었다. 좀민들레의 경우에도 민들레와 거의 유사한 경향을 나타내어 30일 이상의 저온저리와 광조건하의 발아상태가 대조구에 비해 상대적으로 양호하였다. 그러나 서양민들레는 저온무처리구의 광조건에서 발아율 88.8%로 자생 민들레류에 비해 현저히 높게 나타났다. 또한 서양민들레 종자는 저온처리에 의핸 현저한 발아율 향상을 볼 수 없었다. 그러므로 30일 이상의 저온처리에 의해 휴면이 타파되고 발아율이 향상되는 자생 민들레류의 비휴면성인 성양민들에 비해 종 번식에 있어 상대적으로 불리하다는 것을 알 수 있었다.

• KSBB Journal
• /
• v.8 no.1
• /
• pp.55-61
• /
• 1993

Cell lines of Ginkgo biloba were derived from different plant parts and from ten varieties spanning various geographic locations. They had various properties of growth and product formation. More than three flavonol glycosides were present in low concentration in callus and suspension cultures. Cell growth and biosynthesis of flavonol glycosides were found to be affected by medium composition. Culture conditions which influenced cell growth and product formation were also examined. Light stimulated the flavonol glycosides biosynthesis and ten times higher flavonol glycosides content was obtained as compared with the result without light.

• Journal of radiological science and technology
• /
• v.33 no.3
• /
• pp.289-294
• /
• 2010

The purpose of this study is an evaluation of the performance of a detector under radiographic irradiation condition by fabricating the polycrystalline $HgI_2$ film detector. The polycrystalline $HgI_2$ film detectors with thickness of 210 and $320\;{\mu}m$ were fabricated by screen print technology. Measurements of X-ray sensitivity and dark current were performed for two detectors. And measurements of the linearity of X-ray response and reproducibility were performed for the detector of thickness $320\;{\mu}m$. For applied electric field strengths from 0.05 to $2\;V/{\mu}m$ to the detector of thickness $320\;{\mu}m$, the X-ray sensitivities were measured from 233 to $1,408{\times}106\;electrons/mR{\cdot}mm^2$. And the dark currents were measured from 3.2 to $118\;pA/mm^2$. Compared with values reported by Zhong Su et al., the X-ray sensitivities exhibit about two times larger than the X-ray sensitivities measured by Zhong Su et al. And the dark currents exhibit about nine times larger than the dark currents measured by Zhong Su et al. The linearity of X-ray response acquired 0.988 as a coefficient of correlation (r). Reproducibility acquired 0.002 as a coefficient of variation. This study provides the performance data of fabricated polycrystalline $HgI_2$ film detector available for an active matrix flat panel imager under radiographic irradiation condition.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.1C
• /
• pp.63-74
• /
• 2008

Site response analyses were performed based on equivalent linear technique using the local geologic and dynamic site characteristics, which include soil profiles, shear wave velocity profiles and depth to bedrock for 125 sites collected in Korean Peninsula. From the results of site response analyses, 2-parameters site classification system based on the combination of mean shear wave velocity of soil and depth to bedrock was newly recommended for regions of shallow bedrock depth in Korea. First, as the borders of bedrock depth (H) for site classification were determined as 10m and 20m, the soil sites were divided into 3 classes as $H_1$, $H_2$ and $H_3$ sites. And then, the 3 site classes were subdivided into 7 classes based on the mean shear wave velocity of soil ($V_{s,soil}$). The feasibility of new site classification system was verified and the representative site coefficients ($F_a$ and $F_v$) and design response spectrum were suggested by analyzing uniform trend and dispersion of site coefficients for each site class. The suggested site coefficients and the regression curves present the nonlinear characteristics of soils according to the change of rock outcrop acceleration with uniform trend effectively. From the comparison between the mean values of response spectrum which was acquired from the site response analysis and the suggested design response spectrum, there was a little difference in some of site classes and it was verified to adjust the integration interval to make it more suitable for the site condition in Korea.

• Journal of Bio-Environment Control
• /
• v.28 no.3
• /
• pp.265-272
• /
• 2019

The purpose of this study was to investigate the effects of LED and QD-LED (Quantum Dot) irradiation on seed germination, antioxidant ability, and microbial growth, during red radish (Raphanus sativus L.) sprouts cultivation. Irradiated light was blue, red, blue + red and blue + red + far red (QD-LED) lights, and the controls were a fluorescent lamp (FL), and dark condition. Germination rate of red radish was highest in the dark condition. The plant height and fresh weight of red radish sprouts that irradiated each light for 24 hrs after 7 days growing in dark condition, did not shown significantly difference among treatments. After 24 hrs of light irradiation, cotyledon green was best in blue + red light, and the red hypocotyl was excellent in blue light and QD-LED light. DPPH and phenol contents were high in dark and blue + red light treatment, and anthocyanin content was high in blue light and QD-LED light. Total aerobic counts were similar in all treatments and did not show bactericidal effect, whereas E. coli count was lowest in QD-LED light treatment, and yeast and mold counts were lowest in FL only treatment. Results suggest that when red radish seeds were germinated in dark condition and cultivated for 7 days as sprouts, and then treated with blue light or QD-LED light for 24 hrs, the seeds produced good quality red radish sprouts with greenish cotyledon, reddish hypocotyl, high anthocyanin content, and lower level of E coli contamination.

• Korean Journal of Weed Science
• /
• v.11 no.1
• /
• pp.68-73
• /
• 1991

This study was conducted to determine the appropriate culture conditions for developing photoautotrophic cells from tobacco using plant growth regulators, sucrose and light condition in LS medium. The greatest callus induction was observed in the LS medium supplemented with $10^{-5}$ M NAA and $10^{-4}$ M BA, showing 3.08 g of callus fresh weight determined at 30 days after incubation. The highest chlorophyll content of callus was obtained in the LS medium supplemented with $10^{-5}$M NAA and $10^{-6}$ M BA, showing 28.42${\mu}g/g$. In both light and dark conditions, callus induction increased as the concentration of sucrose increased from 0.5%to 3.0%. In particular, in the light condition, the greatest callus induction was made in the LS medium supplemented with 2% sucrose. On the other hand, the heighest chlorophyll content was observed at 0.5% sucrose and chlorophyll wasn't induced in dark condition. The chlorophyll content of callus cultured in LS medium containing 0.75% sucrose was similar to 1% sucrose, as far as the chlorophyll content of callus was concerned.

• Journal of the Mineralogical Society of Korea
• /
• v.5 no.2
• /
• pp.61-71
• /
• 1992

Through the low-temperature(60-150${\circ}C$) hydrothermal treatment of perlite with the alkaline solution at various NaOH concentrations, the mode of volcanic glass alteration and resultant zeolite formation were investigated in a closed system. At a temperature of 80${\circ}C$ and alkalinities of pH range 8 to 12, corresponding to the natural environments of diagenetic zeolite formation, only weak dissolution of perlitic glass occurs without zeolite formation despite the residence time of 100 days. Activities of Si and Al increase progressively, as a consequence of increasing pH, whereas activity ratios of Si/Al decrease. Zeolites were synthesized from perlite in the alkaline solution at above 0.1M NaOH concentrations. Below the temperature of 100${\circ}C$ Na-P was mainly formed, whereas analcime was the dominant zeolite at the temperature range of 100-150${\circ}C$. During Na-P synthesis chabazite and Na-X were also formed as by-products in case of lower proportion of solution/sample(<10ml/g) and higher NaOH concentraion (>3M), respectively. The alteration modes of perlite in the zeolite synthesis reflect that the formation of synthetic zeolites occurs as an incongruent dissolution likely with the diagenetic formation of natural zeolites from volcanic glass. Considering much difference in reaction kinetics between natural and synthetic systems, however, the evaluated synthetic conditions in these experiments were not directly applicable to the natural diagenetic system.

• Development and Reproduction
• /
• v.12 no.3
• /
• pp.231-241
• /
• 2008

The present study was designed to clarify aspects of the annual reproductive cycle of the fresh water mitten crab, Eriocheir japonicus inhabiting Sumjin river, and to determine the adequate conditions of temperature, photoperiod and salinity on the gonadal maturation and breeding of adult female crabs. Based on the seasonal changes of GSIs and gonadal histology of adult crabs, the annual reproductive cycle could be divided into 4 periods as follows: previtellogenesis period (from September to October) when GSIs were low value and ovaries had oocytes in previtellogenesis stage and meiotic prophase stage; maturing period (from November to March of the next year) when GSIs increased gradually and ovarian oocytes accumulated yolk globules; spawning period (from April to June) when high value of GSI of female was kept and ovigerous female appeared; resting period (from July to August) when GSIs decreased rapidly, and vitellogenic oocytes degenerated. Gonadal maturation was influenced by water temperature, but not photoperiod and salinity. GSI more increased in experimental regime of $18^{\circ}C$ than that of $10^{\circ}C$ regardless of photoperiod conditions (12L12D and 15L9D). However, in $26^{\circ}C$ regime of both photoperiod conditions, the value of GSI was not changed, and vitellogenic oocytes were not observed. Spawning was considerably influenced by water temperatures and salinities regardless of photoperiods. Vitellogenic female crabs did not spawn at $10^{\circ}C$ in any salinity conditions. However, at $18^{\circ}C$ and $26^{\circ}C$, over a half of rearing female crabs spawned in condition of 30% sea water (salinity 9.6%o) and 60% sea water (salinity 19.2%o), while no female spawned in freshwater condition (salinity 0.0%o).

• Economic and Environmental Geology
• /
• v.24 no.1
• /
• pp.57-62
• /
• 1991

This study presents results of thermal stress calculations around the uplifted province within the continental lithosphere. A set of thermal stresses for the uplifted provinces are calculated using by assumption of two dimensions along the extension of the strike. The calculations utilize thermoelastic displacement potential function. Thermal stress distribution-faulting conditions inferred from this study are consistent with the suggested surface heat flow and place an important constraint on the thermal state of the uplifted provinces within the continental lithosphere.