• Korean Journal of Remote Sensing
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• v.36 no.2_1
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• pp.167-178
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• 2020

KOMPSAT-3A images have been used in various kinds of applications, since its launch in 2015. However, there were limits to scientific analysis and application extensions of these data, such as vegetation index estimation, because no tool was developed to obtain the surface reflectance required for analysis of the actual land environment. The surface reflectance is a product of performing an absolute atmospheric correction or calibration. The objective of this study is to quantitatively verify the accuracy of top-of-atmosphere reflectance and surface reflectance of KOMPSAT-3A images produced from the OTB open-source extension program, performing the cross-validation with those provided by a site measurement data of RadCalNet, an international Calibration/Validation (Cal/Val) portal. Besides, surface reflectance was obtained from Landsat-8 OLI images in the same site and applied together to the cross-validation process. According to the experiment, it is proven that the top-of-atmosphere reflectance of KOMPSAT-3A images differs by up to ± 0.02 in the range of 0.00 to 1.00 compared to the mean value of the RadCalNet data corresponding to the same spectral band. Surface reflectance in KOMPSAT-3A images also showed a high degree of consistency with RadCalNet data representing the difference of 0.02 to 0.04. These results are expected to be applicable to generate the value-added products of KOMPSAT-3A images as analysisready data (ARD). The tools applied in thisstudy and the research scheme can be extended as the new implementation of each sensor model to new types of multispectral images of compact advanced satellites (CAS) for land, agriculture, and forestry and the verification method, respectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.2
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• pp.140-145
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• 2018

This paper deals with the dynamical analysis of a two-point mooring vessel under surge excitations. The characteristics of nonlinear behaviors are investigated completely including bifurcation and limit cycle according to particular input parameter changes. The strong nonlinearity of the mooring system is mainly caused by linear and cubic terms of restoring force. The numerical simulation is performed based on the fourth order Runge-Kutta algorithm. The bifurcation diagram and several instability phenomena are observed clearly by varying amplitudes as well as frequencies of surge excitations. Stable periodic solutions, called the periodic windows, can be obtained in succession between chaotic clouds of dots in case of frequency ${\omega}=0.4rad/s$. In addition, the chaotic region is unexpectedly increased when external forcing amplitude exceeds 1.0 with the angular frequency of ${\omega}=0.7rad/s$. Compared to the cases for ${\omega}=0.4$, 0.7rad/s, the region of chaotic behavior becomes more fragile than in the case of ${\omega}=1.0rad/s$. Finally, various types of steady states including sub-harmonic motion, limit cycle, and symmetry breaking phenomenon are observed in the two-point mooring system at each parameter value.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.109-112
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• 2002

Using Monte Carlo calculations the effects of longitudinal magnetic fields on the beam profiles produced by clinical electron beam were studied. The Monte Carlo calculations were performed using the EGS4 code system modified to account for external magnetic fields. The beam profiles for a 6 MeV electron beam with longitudinal magnetic fields of 0.5-3.0 T were calculated. As a result of these calculations we found that the penumbra widths can be reduced with increased magnetic fields. This means that the electron therapy benefits from the external magnetic fields.

• Radiation Oncology Journal
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• v.2 no.1
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• pp.101-106
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• 1984

Various methods are available for determination of exposure time in intracavitary radiotherapy of the carcinoma of the uterine cervix. To determine the accuracy of dose calculation with isodose curve for TAO applicator, comparison with results calculated by computer for radiotherapy treatment Planning was done in 24 procedures done in 12 consecutive patients with the carcinoma of the uterine cervix from May to December, 1983. The results are as follows: 1. The average dose rate Per hour of Point A was 87.70 rad, being 89.91 rad ana 85.49 rad in left and right, respectively. 2. The average percentage of dose rate of point A calculated by isodose curve method over that by computer was $101.28\%$ and the difference was less than $5\%$ in 17 Procedures and over $10\%$ in only 3 procedures. 3. The average percentage in case of point B was $108.67\%$. In conclusion, in most cases the difference was less than 200 rad for point A and less than 100 rad for point B during 2 courses of intracavitary radiotherapy. And so the dose rate calculation with isodose curve for TAO applicator is comparatively accurate.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.763-767
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• 2014

Aim: To study the contribution of genetic variation in RAD51 to risk of esophageal squamous cell carcinoma (ESCC). Methods: Three single nucleotide polymorphisms (SNPs) in RAD51 (rs1801320, rs4144242 and rs4417527) were genotyped in 316 ESCC patients and 316 healthy controls in Anyang area of China using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism). Demographic variables between cases and controls were statistically compared by T test and Chi-square test. Hardy-Weinberg equilibrium was evaluated by the Chi-square test. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to measure any association with ESCC. Haplotype frequencies were estimated by Phase 2.1. Result: The genotype frequencies of rs1801320, rs4144242 and rs4417527 in patients with ESCC demonstrated no significant differences from those in control group (P>0.05). When the haplotypes of these three SNPs were constructed and their relationships with ESCC risk investigated, however, CGG was observed to increase the risk (P=0.020, OR=2.289). Conclusions: There was no association between the three SNPs of RAD51 and ESCC susceptibility in our Chinese population. However, the CGG haplotype might be a risk factor.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.405-411
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• 2017

Homologous recombination occurs between homologous chromosomes and is significantly involved in programmed double-strand break (DSB) repair. Activation of two recombinases, Rad51 and Dmc1, is essential for an interhomolog bias during meiosis. Rad51 participates in both mitotic and meiotic recombination, and its strand exchange activity is regulated by an inhibitory factor during meiosis. Thus, activities of Rad51 and Dmc1 are coordinated to promote homolog bias. It has been reported that Hed1, a meiosis-specific protein in budding yeast, regulates Rad51-dependent recombination activity. Here, we investigated the role of Hed1 in meiotic recombination by ectopic expression of the protein after pre-meiotic replication in Saccharomyces cerevisiae. DNA physical analysis revealed that the overexpression of Hed1 delays the DSB-to-joint molecule (JM) transition and promotes interhomolog JM formation. The study indicates a possible role of Hed1 in controlling the strand exchange activity of Rad51 and, eventually, meiotic crossover formation.

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.240-241
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• 1999

• The Pure and Applied Mathematics
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• v.15 no.3
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• pp.259-296
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• 2008

Let A be a noncommutative Banach algebra. Suppose there exists a continuous linear Jordan derivation D : A $\rightarrow$ A such that $D(x)^2$[D(x),x] $\in$ rad(A) or [D(x),x]$D(x)^2$ $\in$ rad(A) for all x $\in$ A. In this case, we have D(A) $\subseteq$ rad(A).

• The Pure and Applied Mathematics
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• v.15 no.2
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• pp.179-201
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• 2008

Let A be a noncommutative Banach algebra. Suppose there exists a continuous linear Jordan derivation $D\;:\;A{\rightarrow}A$ such that $D(x)[D(x),x]^2\;{\in}\;rad(A)$ or $[D(x), x]^2 D(x)\;{\in}\;rad(A)$ for all $x\;{\in}\ A$. In this case, we have $D(A)\;{\subseteq}\;rad(A)$.

• Communications of the Korean Mathematical Society
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• v.34 no.3
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• pp.811-818
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• 2019

Let A be a Banach algebra with rad(A). We show that if there exists a continuous linear Jordan derivation D on A, then $$[D(x),x]D(x)^2{\in}rad(A)$$ if and only if $D(x)[D(x),x]D(x){\in}rad(A)$ for all $x{\in}A$.