• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.127-131
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• 2002

Critical nitrogen concentration (Nc), which is defined as the minimum % N in shoots required to maintain the maximum growth rate of top dry weight (W) at any time, was determined for rice plant. Using two rice varietal groups, japonica varieties and an indica $\times$ japonica "Dasanbyeo", 18 data points fulfilling the statistical criteria for determining Nc were obtained through eight N-fertilization experiments over two years at Suwon (37$^{\circ}$16'N), Korea. Nc dilution curve for each variety was obtained by fitting the Nc-W relationship to power function. However, The critical nitrogen curves for the two variety groups were not different statistically. Thus, a Nc dilution curve was fitted for the Nc data points pooled over the two variety groups and proposed in rice as: Nc=4.08, where W＜1.73 t h $a^{-1}$ , Nc=5.197 $W^{0.425}$3/ ($R^2$=0.964), where 1.73 t h $a^{-1}$ ＜W＜12 t h $a^{-l}$. The Nc for W＜1.73 t h $a^{-l}$ were estimated as a constant value of 4.08%, the mean value of the maximum N concentration for N-limiting condition and the minimum N concentration for N non-limiting condition. The model for Nc is applicable to diagnosing the nitrogen nutrition status during the rice growth period from emergence to heading stage. The Nc curve well discriminated the 144 data points between the N limiting and the N non-limiting groups regardless of varieties, cultural methods, and years.-limiting groups regardless of varieties, cultural methods, and years.

• Journal of the Chungcheong Mathematical Society
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• v.27 no.4
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• pp.563-569
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• 2014

We investigate a minimal set of generators of a homogeneous ideal of a curve of degree d on a linearly normal smooth surface scroll W in $P^r$ whose arithmetic genus is maximal among curves of degree d on W.

• Journal of the Chungcheong Mathematical Society
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• v.36 no.1
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• pp.1-8
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• 2023

Let C be a smooth projective curve and W a symplectic bundle over C of degree w. Let π : 𝕃𝔾(W) → C be the relative Lagrangian Grassmannian over C and S_d(W) be the space of Lagrangian subbundles of degree w -d. Then Kontsevich's space ${\bar{\mathcal{M}}}_g$(𝕃𝔾(W), β_d) of stable maps to 𝕃𝔾(W) is a compactification of S_d(W). In this article, we give an upper bound on the dimension of ${\bar{\mathcal{M}}}_g$(𝕃𝔾(W), β_d), which is an analogue of a result in [8] for the relative Lagrangian Grassmannian.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.63-65
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• 2021

This paper describes an integrated H/W-S/W implementation of elliptic curve digital signature algorithm (EC-DSA) using a security system-on-chip (SoC). The security SoC uses the Cortex-A53 APU as CPU, and the hardware IPs of high-performance elliptic curve cryptography (HP-ECC) core and SHA3 (secure hash algorithm 3) hash function core are interfaced via AXI4-Lite bus protocol. The signature generation and verification processes of EC-DSA were verified by the implementation of the security SoC on a Zynq UltraScale+ MPSoC device.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.409-429
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• 2006

In designing rock-socketed drilled shaft, bearing capacity evaluation is very important because the maximum values of base and side resistance are not generally mobilized at the same value of displacement, FHWA and AASHTO code suggest different ultimate bearing capacity formular according to rock type and shaft settlement. In domestic code suggest base resistance and side resistance can be added on condition that after confirming the result of field load test with axial load transfer test. This paper shows that static load test and hi-directional load test result analysis of deep rock-socketed drilled shaft in three different sites. Load-settlement curve, t-z, and q-w curve in rock-socketed part were calculated and compared. t-z curve in weathered and soft rock showed no deflection softening behavior in pretty large strain (about 2-3% of diameter). Ultimate resistance could be the summation of side resistance and base resistance in rock-socketed drilled shaft in domestic sites.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.278-281
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• 2011

This system can predict the maximum output about all illumination levels so that the PV system designer can design the system having the best efficiency. For the output prediction exact about the solar cell, that is the device the basis most in the PV system, the basis has to be in order to try this way. The solution based on Lambert W-function are presented to express the transcendental current-voltage characteristic containing parasitic power consuming parameters like series and shunt resistances. A simple and efficient method for the extraction of a single current-voltage (I-V) curve under the constant illumination level is proposed. With the help of the Lambert W function, the explicit analytic expression for I is obtained. And the explicit analytic expression for V is obtained. This analytic expression is directly used to fit the experimental data and extract the device parameters. The I-V curve of the solar cell was expressed through the modeling using Lambert W-function and the numerical formula where there is the difficulty could be logarithmically expressed This method expresses with the I-V curve through the modeling using Lambert W-function which adds other loss ingredients to the equation2 as to the research afterward. And the solar cell goes as small and this I-V curve can predict the power penalty in the system unit.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.118-121
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• 2006

The research reported here is concerned with the effects of the fiber combination condition and water/cement ratio on the mechanical properties of high performance fiber-reinforced cementitious composites(HPFRCC). An experimental investigation of the behavior of steel cords(SC) and SC and Polyethylene(PE) hybrid fiber reinforced cementitious material under compressive and tensile loading is presented. In this experimental research, the tensile and compressive strength and strain capacity of HPFRCC were selected using the cylindrical specimens. The results show that W/C ratio is a significant effect factor on the compressive and tensile performance of HPFRCC. The envelope curve concept applies to hybrid fiber-reinforced cementitious composites in tension just as it does to compressive stress-strain curve of fiber-reinforced cement composites. For practical purposes, the tensile envelope curve may be taken to be the same as the monotonic tensile stress-strain curve.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.455-465
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• 2008

In this study, the load distribution and deformation of rock-socketed drilled shafts subjected to axial load are investigated based on small scale model tests. In order to analyze the effects of major influencing factors of end bearing capacity, Hoek-cell triaxial tests were performed. From the test results, it was found that the initial slope of end bearing load transfer (q-w) curve was highly dependent on rock mass modulus and pile diameter, while the ultimate unit toe resistance ($q_{max}$) was influenced by rock mass modulus and the spacing of discontinuities. End bearing load transfer function of drilled shafts socketed in rock was proposed based on the Hoek-cell triaxial test results and the field loading tests which were performed on granite and gneiss in South Korea. Through the comparison with pile load tests, it is found that the load-transfer curve by the present study is in good agreement with the general trend observed by field loading tests, and thus represents a significant improvement in the prediction of load transfer of drilled shaft.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.3
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• pp.233-244
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• 2001

Stress-strain behaviour of soil varies based on stress path and stress history. There has been few study on the characteristics of yielding curve which has anisotropic compression stress history in decomposed granite soil. During this study, various stress path tests in previous anisotropic compression stress history are performed on compacted decomposed granite soil sampled at Iksan, Chonbuk. Yielding points are determined from various stress-strain curves (${\eta}-{\varepsilon}$, ${\eta}$-v, and ${\eta}$-k, ${\eta}$-W curves). Stress-strain curve is certified which shows yielding point very clearly. The shape and characteristics of anisotropic compression yielding curves are examined. The main results are summarized as follows : 1) p' constant and compressive direction in stress paths, which has experienced previous anisotropic compression stress history, shows relatively dear yielding points. 2) Yielding curves defined from ${\eta}$-k and ${\eta}$-W curve show almost perfect ellipse. 3) Directions of plastic strain incremental vector($dv^p/d{\varepsilon}^p$) are not perpendicular to yielding curve.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1577-1578
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• 2013