• Horticultural Science & Technology
• /
• v.31 no.1
• /
• pp.50-55
• /
• 2013

The objective of this research was to investigate the impact of Ca fertilizer on the growth of mother plants, physiological disorders, and occurrence of daughter plants in propagation of 'Seolhyang' strawberry through plastic bag cultivation. To achieve this, chemicals of 1.125 mM $Ca(OH)_2$, 0.375 mM $MgCl_2$, 1.250 mM KCl were blended and designated to combined fertilizer (CF). Then, the effect was compared to the treatment of no Ca application (control) and a commercial fertilizer, CalMag (13-0-1.9-16-6:N-$P_2O_5$-$K_2O$-CaO-MgO), when those were applied every two weeks with controlled electrical conductivity (EC) of solution such as 0.6 or 1.0 $dS{\cdot}m^{-1}$. The number of plants showing Ca deficiency symptoms was the highest in control treatment, but those decreased significantly in CF or CalMag treatments. The differences between CF and CalMag in appearance of Ca deficient plants were not significant when two fertilizers were applied with same EC. The fresh and dry weights of mother plants were the greater in the treatments of CF or CalMag than those of control treatment. The treatments of 1.0 $dS{\cdot}m^{-1}$ of CF or CalMag were more effective than those of 0.6 $dS{\cdot}m^{-1}$ on the fresh and dry weight of the mother plants. The runner lengths in the treatment of 1.0 $dS{\cdot}m^{-1}$ of CF were the longest among the all treatments tested. The treatments of 1.0 $dS{\cdot}m^{-1}$ were more effective than those of 0.6 $dS{\cdot}m^{-1}$ of CF or CalMag in lengths and fresh and dry weight of runners. The fresh and dry weights of daughter plants were heavier in the treatments of CF than those of CalMag. Based on the above results, we concluded that the Ca deficiency in raising 'Seolhyang' strawberry can be lessened by the application of Ca containing fertilizers, but combined application of Ca, K and Mg was more effective than that of Ca alone for seedling production.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2002.11a
• /
• pp.136-137
• /
• 2002

The study was conducted to examine noise levels influenced by differences of altitudes and elevation from ground level. The results of the study indicated that when the noise (102 db) was created at the upper part of a steep slope area, the noise levels measured at the altitudes of 5 and 10 m were 70 and 62.1 db (R$^2$=0.9533), respectively, and that when the noise (102 db) was created at the lower part of the area, the noise levels levels measured at the altitudes of 5 and 10 m were 74.6 and 71.8 db (R$^2$=0.8519), respectively. When noise was created on a nat area, the noise levels at 10, 20 and 50 meter-ranges were 76.2, 65.9 and 55.3 db (R2 =0.9854), respectively, in which the longer distances from the noise source reduced the noise levels than the shorter and especially the noise was tremendously reduced within 10 meter-range.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1997.10a
• /
• pp.183-189
• /
• 1997

This research is a experimental study for the machining conditions of E. D. M. They were used Cu electrode and the various amplitude of current waves for the machining by E.D.M. By the analyse the characteristics of current, voltage, roughness of surface and over cut, the next results were obtained. E.D.M. machining time become to be more longer by the increasing the tensile stress. In case of NAK 55 as the composite resin, the machining time was more faster without the relationship for the tensile stress. And if it was more increased the amplitude of Ip, it has been more faster in the machining time and more poor in the surface roughness. But it was increased Ip with 5A, it has been increased 0.3 time in over cut. So, if we want to be the precision machining, the diameter of the electrode should be more smaller than the diameter of machined hole in workpiece with E.D.M.

• Nonlinear Functional Analysis and Applications
• /
• v.27 no.2
• /
• pp.309-322
• /
• 2022

In this paper, we introduce the notion of a new generalized type of rational F-contraction mapping. Further, the concept is used to obtain fixed points in a complete b-metric space. We also prove another unique fixed point theorem in the context of b-metric space. Our results are verified with example.

• Reproductive and Developmental Biology
• /
• v.36 no.1
• /
• pp.13-19
• /
• 2012

In order to provide the basis for developing practical mouse embryonic stem cells (mESCs) culture method, how the endogenous level of self-renewal-stimulating factor genes was altered in the mESCs by different extracellular signaling was investigated in this study. For different extracellular signaling, mESCs were cultured in 2 dimension (D), 3D and integrin-stimulating 3D culture system in the presence or absence of leukemia inhibitory factor (LIF) and transcriptional level of $Lif$, $Bmp4$ and $Wnt3a$ was evaluated in the mESCs cultured in each system. The expression of three genes was significantly increased in 3D system relative to 2D system under LIF-containing condition, while only $Wnt3a$ expression was increased by 3D culture under LIF-free condition. Stimulation of integrin signaling in mESCs within 3D system with exogenous LIF significantly up-regulated transcriptional level of $Bmp4$, but did not induce transcriptional regulation of $Lif$ and $Wnt3a$. In the absence of LIF inside 3D system, the expression of $Lif$ and $Bmp4$ was significantly increased by integrin signaling, while it significantly decreased $Wnt3a$ expression. Finally, the signal from exogenous LIF significantly caused increased expression of $Lif$ in 2D system, decreased expression of $Bmp4$ in both 2D and 3D system, and decreased expression of $Wnt3a$ in integrin-stimulating 3D system. From these results, we identified that endogenous expression level of self-renewal-stimulating factor genes in mESCs could be effectively regulated through artificial and proper manipulation of extracellular signaling. Moreover, synthetic 3D niche stimulating endogenous secretion of self-renewal-stimulating factors will be able to help develop growth factor-free maintenance system of mESCs.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.10
• /
• pp.3917-3922
• /
• 2010

In this paper, 3 stage amplifier MMIC was designed and fabricated with U-band optimized epitaxal pHEMT that produced by large signal characterization and modeling for 60 GHz band. The pHEMT used in this paper, the gate $0.12\;{\mu}m$ length and total gate width of $100\;{\mu}m$, $200\;{\mu}m$ has been modeled using the large signal designed with negative feedback and MCLF instead of MIM capacitor for improving stability. Fabricated MMIC $2.5{\times}1.5mm^2$ size, current about 40 mA, operating frequency 59.5~60.5 GHz, gain 19.9~18.6 dB, input matching characteristics -14.6~-14.7 dB, output matching characteristics -11.9~-16.3 dB and output -5 dBm characteristics were obtained.

• The Korean Journal of Mycology
• /
• v.16 no.1
• /
• pp.9-15
• /
• 1988

Two kinds of toxins were demonstrated in the culture filtrate of H. sativum, and were called 'M' and 'D' toxins. The lettuce bioassay indicated that D-toxin caused less root growth inhibition than M-toxin. Chemical analysis indicated that M-toxin was a very unusual small peptide. D-toxin was shown to have chemical characteristics similar to helminthosporal based on ultraviolet, proton nuclear magnetic resonance and mass spectra. D-toxin was composed of at least two isomers.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.36C no.9
• /
• pp.13-19
• /
• 1999

This paper describes a design of an 8-bit 100KSPS 1mW CMOS A/D Converter. Using a novel systematic offset cancellation technique, we reduce the systematic offset voltage of operational amplifiers. Further, a new Gain amplifier is proposed. The proposed A/D Converter is fabricated with a $0.6{\mu}m$ single-poly triple-metal n-well CMOS technology. INL and DNL is within ${\pm}1LSB$, and SNR is about 43dB at the sampling frequency of 100KHz. The power consumption is $980{\mu}W$ at +3V power supply.

• Journal of Bio-Environment Control
• /
• v.27 no.2
• /
• pp.185-190
• /
• 2018

This study was conducted to investigate the optimum electrical conductivity (EC) levels of nutrient solution for growth of mother plants and increasing occurrence of daughter plants of strawberry ($Fragaria{\times}ananassa$ Duch. cv. Maehyang) using hydroponics. The mother plants of strawberry were transplanted in cultivation pot ($61{\times}27{\times}18cm$) filled with coir medium on March 22, 2017. Nutrient solution was supplied by the drip tape at $0.6dS{\cdot}m^{-1}$ of EC levels for rooting during 11 days. After rooting, the mother plants of strawberry was treated at the EC levels of 0.6, 1.2 or $1.8dS{\cdot}m^{-1}$, respectively. Growth characteristics, such as mother plants and daughter plants of strawberry were measured at 100 days after transplanting. The plant height of mother plant was significantly higher at $0.6dS{\cdot}m^{-1}$ treatment, and the crown diameter of mother plant was significantly greater at $1.8dS{\cdot}m^{-1}$ treatment. The fresh and dry weights of shoot were higher at both 0.6 and, $1.2dS{\cdot}m^{-1}$ treatments. The number of runners was not significantly different in all treatments. The fresh and dry weights of runner were heavier at $0.6dS{\cdot}m^{-1}$ than other treatments. The number of daughter plants was the highest, 16.7 at the $1.2dS{\cdot}m^{-1}$ treatment. However, the fresh and dry weights of third daughter plant were the heaviest at $0.6dS{\cdot}m^{-1}$ treatment. Although the daughter plants were a large of production at $1.2dS{\cdot}m^{-1}$ treatment, the low EC levels of strawberry were positive in terms of seedling quality during nursery. These results indicated that growth of mother plant and occurrence of daughter plants were greater at the EC $0.6dS{\cdot}m^{-1}$ nutrient solution for hydroponic cultivation of 'Maehyang' strawberry during nursery period.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.4
• /
• pp.358-363
• /
• 2000

This study was carried out to obtain the basic data for selecting the applicable crops in reclaimed land during desalinization period. A pot experiment was conducted with 5 different electrical conductivities of the saturated extracts $(ECe\;1,\;3,\;9,\;14,\;and\;16\;dS{\cdot}m^{-1})$ of soils taken from the Dae-Ho reclaimed tidal lands. Eight crops (Chinese cabbage, radish, tomato, red pepper, buckwheat, soybean, sesame, and green perilla) were grown for 37days. Plant height and number of leaves were surveyed on 2 and 4 weeks after seeding, and on harvest time (5 weeks). After harvest, dry weights of harvested crops were measured and soil chemical properties were analyzed. Emergence rates of crops were comparatively high except sesame. For sesame, there was no emergence at ECe over $3\;dS{\cdot}m^{-1}$. Growth and dry weight decreased significantly as increasing ECe. The ECe which decreased 50% of dry weight index were $14.2\;dS{\cdot}m^{-1}$ for radish, $11.4\;dS{\cdot}m^{-1}$ for Chinese cabbage, $10.2\;dS{\cdot}m^{-1}$ for red pepper, $8.9\;dS{\cdot}m^{-1}$ for buckwheat and green perilla, $8.6\;dS{\cdot}m^{-1}$ for soybean, and $8.9\;dS{\cdot}m^{-1}$ for tomato. At higher ECe that start the growth inhibition, increasing $1\;dS{\cdot}m^{-1}$ in ECe, 7.7, 6.5, 5.9, 5.6, 5.2, and 4.9% of dry weight decreased for buckwheat, green perilla, Chinese cabbage, radish, soybean, and tomato (red pepper), respectively. The critical value of ECe for crop survival except sesame was $15.4\;{\sim}\;23.1\;dS{\cdot}m^{-1}$.