• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.3 s.94
• /
• pp.327-334
• /
• 2005

In this paper, a new PAPR reduction method using correlation of input data sequence is proposed in order to overcome the serious drawbacks, such as necessity of side information transmission or increase of system complexity and calculation which are the basis of previous SLM, PTS and DSI method. A new PAPR reduction method can be classified into Method 1 and Method 2. Method 1 reduces the correlation between the smallest sub-sequence and neighbor smallest sub-sequence. And, to consider the own correlation in detail, the Method 2 reduces two case of correlation between neighbor smallest sub-sequences and neighbor largest sub-sequences. According to simulation result, Method 1 and Method 2 has about 0.5 $\~$ O.8 dB and 1 $\~$ l.2 dB PAPR reduction effect respectively. If more detailed process to reduce the correlation of input data sequence is considered, we can achieve better PAPR reduction performance.

• Korean Journal of Remote Sensing
• /
• v.23 no.5
• /
• pp.335-346
• /
• 2007

This study is aiming at improving the Environmental Conservation Value Assessment Map(ECVAM) of National Land in Korea. The ECVAM items are composed of legal and environmental/ecological assessments. A popular method applied to ECVAM is an overlay environmental/ecological assessment items. The purpose of this study is to offer complementary items of the ECVAM by examining assessment items. In this study we assessed the ECVAM by five methods. Method 1 is Grade 1 areas of each administrative district; Method 2 is comparing overlapped areas of each assessment items Grade 1, 2 and permission of each assessment items duplication; Method 3 is Grade 1, 2 areas by only singular assessment items; Method 4 is Grade 1 areas only of Method 2; and Method 5 is Grade 2 areas only of Method 2. Method 1 showed Seoul and other metropolitan cities revealed a large proportion of Grade I regions by the legal assessment items. Gang won-Do, showed a large proportion of Grade I regions by the environmental/ecological assessment item. Method 2 showed 93.4% of diameter Grade II(standard for stability); forest diameter item accounted for 99.9% by Method 3, Method 4 showed 95.7% of forest diameter, and forest density accounted for 66.4% by Method 5. This study contributes to reduce the complexity in the process of manufacturing ECVAM of National Land, and to raise the flexibility in the process of managing and updating this map.

• Nuclear Engineering and Technology
• /
• v.55 no.4
• /
• pp.1350-1364
• /
• 2023

2D/1D coupling method is an important neutron transport calculation method due to its high accuracy and relatively low computation cost. However, 2D/1D coupling method may diverge especially in small axial mesh size. To analyze the convergence behavior of 2D/1D coupling method, a Fourier analysis for k-eigenvalue neutron transport problems is implemented. The analysis results present the divergence problem of 2D/1D coupling method in small axial mesh size. Several common attempts are made to solve the divergence problem, which are to increase the number of inner iterations of the 2D or 1D calculation, and two times 1D calculations per outer iteration. However, these attempts only could improve the convergence rate but cannot deal with the divergence problem of 2D/1D coupling method thoroughly. Moreover, the choice of axial solvers, such as DGFEM SN and traditional SN, and its effect on the convergence behavior are also discussed. The results show that the choice of axial solver is a key point for the convergence of 2D/1D method. The DGFEM SN based 2D/1D method could converge within a wide range of optical thickness region, which is superior to that of traditional SN method.

• Journal of Wetlands Research
• /
• v.25 no.2
• /
• pp.75-82
• /
• 2023

Data for measuring the flow rate of streams are used as important basic data for the development and maintenance of water resources, and many experts are conducting research to make more accurate measurements. Especially, in Korea, monsoon rains and heavy rains are concentrated in summer due to the nature of the climate, so floods occur frequently. Therefore, it is necessary to measure the flow rate most accurately during a flood to predict and prevent flooding. Thus, the U.S. Geological Survey (USGS) introduces 1, 2, 3 point method using a flow meter as one way to measure the average flow rate. However, it is difficult to calculate the average flow rate with the existing 1, 2, 3 point method alone.This paper proposes a new 1, 2, 3 point method formula, which is more accurate, utilizing one probabilistic entropy concept. This is considered to be a highly empirical study that can supplement the limitations of existing measurement methods. Data and Flume data were used in the number of holesman to demonstrate the utility of the proposed formula. As a result of the analysis, in the case of Flume Data, the existing USGS 1 point method compared to the measured value was 7.6% on average, 8.6% on the 2 point method, and 8.1% on the 3 point method. In the case of Coleman Data, the 1 point method showed an average error rate of 5%, the 2 point method 5.6% and the 3 point method 5.3%. On the other hand, the proposed formula using the concept of entropy reduced the error rate by about 60% compared to the existing method, with the Flume Data averaging 4.7% for the 1 point method, 5.7% for the 2 point method, and 5.2% for the 3 point method. In addition, Coleman Data showed an average error of 2.5% in the 1 point method, 3.1% in the 2 point method, and 2.8% in the 3 point method, reducing the error rate by about 50% compared to the existing method.This study can calculate the average flow rate more accurately than the existing 1, 2, 3 point method, which can be useful in many ways, including future river disaster management, design and administration.

• Electrical & Electronic Materials
• /
• v.8 no.2
• /
• pp.158-164
• /
• 1995

Solid solutions Sr$_{2}$(Ta$_{1-x}$ Nb$_{x}$)$_{2}$O$_{7}$, (x=0.0-1.0), composed of strontium tantalate(Tc=-107.deg. C) and strontium-niobate(Tc=1342.deg. C) were prepared by the conventional mixed oxide method and the flux method(molten salt synthesis method). Phase relation, sintering temperature, grain-orientation and dielectric properties for sintered ceramic samples were investigated with different compositions. Both Curie temperature and dielectric constant at Curie temperature were increased, and sintering behavior and the degree of grain-orientation were improved with the increase of Nb content. The single phase Sr$_{2}$(Ta/sib 1-x/Nb$_{x}$)$_{2}$O$_{7}$ powder was synthesized by using the flux method at lower temperatures, and sintering temperature was also reduced by using the flux method-derived powder than using the mixed oxide-derived powder. Sintering characteristics and dielectric properties of the specimens prepared by the flux method were better than those derived through the conventional mixed oxide method.thod.hod.

• The Pure and Applied Mathematics
• /
• v.24 no.1
• /
• pp.21-31
• /
• 2017

In this paper, we introduce and solve the following additive (${\rho}_1$, ${\rho}_2$)-functional inequality $${\Large{\parallel}}2f(\frac{x+y}{2})-f(x)-f(y){\Large{\parallel}}{\leq}{\parallel}{\rho}_1(f(x+y)+f(x-y)-2f(x)){\parallel}+{\parallel}{\rho}_2(f(x+y)-f(x)-f(y)){\parallel}$$ where ${\rho}_1$ and ${\rho}_2$ are fixed nonzero complex numbers with $\sqrt{2}{\mid}{\rho}_1{\mid}+{\mid}{\rho}_2{\mid}<1$. Using the fixed point method and the direct method, we prove the Hyers-Ulam stability of the additive (${\rho}_1$, ${\rho}_2$)-functional inequality (1) in complex Banach spaces.

• Nuclear Engineering and Technology
• /
• v.54 no.1
• /
• pp.19-29
• /
• 2022

The 2D/1D method has become the mainstream of the direct transport calculation considering the balance of accuracy and efficiency. However, the 2D/1D method still suffers from stability issues. Recently, a quasi-3D method has been proposed with axial Legendre expansion. Analysis and comparison of the 2D/1D and quasi-3D method is conducted in theory from the equation derivation. Besides, the C5G7 benchmark, the KUCA benchmark and the macro BEAVRS benchmark are calculated to verify the theory comparisons of these two methods with the direct transport code SHARK. All results show that the quasi-3D method has better stability and accuracy than the 2D/1D method with worse efficiency and memory cost. It provides a new option for direct transport calculation with the quasi-3D method.

• Bulletin of the Korean Mathematical Society
• /
• v.49 no.1
• /
• pp.175-195
• /
• 2012

Representing planar Pythagorean hodograph (PH) curves by the complex roots of their hodographs, we standardize Farouki's double cubic method to become the undetermined junction point (UJP) method, and then prove the generic existence of solutions for general $C^1$ Hermite interpolation problems. We also extend the UJP method to solve $C^2$ Hermite interpolation problems with multiple PH cubics, and also prove the generic existence of solutions which consist of triple PH cubics with $C^1$ junction points. Further generalizing the UJP method, we go on to solve $C^2$ Hermite interpolation problems using two PH quintics with a $C^1$ junction point, and we also show the possibility of applying the modi e UJP method to $G^2[C^1]$ Hermite interpolation.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.21 no.1
• /
• pp.39-43
• /
• 2017

Purpose Thyroglobulin (Tg) is a biologic marker of differentiated thyroid carcinoma (DTC), produced by normal thyroid tissue or thyroid cancer tissue. Therefore, the Tg values of DTC patients is the most specific indicator for judging whether recurrence occur or whether the remaining thyroid cancer is present. Thyroid cancer is currently the most common cancer in Korea, of which 90% is differentiated thyroid cancer. The number of patients with thyroid disease of this application also increased, and an accurate and prompt results are required. However, the incubation time of the Tg commonly takes about 24 hours in our hospital, and the result reporting time is delayed, and We could not satisfied with the requirements of clinical departments and patients. In order to fulfill these requirements, experiments were conducted by shortening the incubation time between company B's Kit currently in use and company C's Kit used in other hospitals. Through these experiments, we could perform the correlation with the original method and shortening method, and could find the optimum reaction time to satisfy the needs of the departments and the patients, and we will improve the competitiveness with the EIA examination. Materials and Methods In September 2016, we tested 65 patients company B's kit and company C's kit by three incubation ways. First method $37^{\circ}C$ shaking 2hr/2hr, Second method RT shaking 3hr/2hr, Third method 1hr/1hr shaking at $37^{\circ}C$. Fourth method RT shaking 3hr method which is the original method of Company C's Kit. Fifth method, the incubation time was shortened under room temperature shaking 2hr, Sixth method $37^{\circ}C$ shaking 2hr. And we performed and compared the correlation and coefficient of each methods. Results As a result of performing shortening method on company B currently in use, when comparing the Original method of company B kit, First method $37^{\circ}C$ shaking 2hr/2hr was less than Tg 1.0 ng/mL and the ratio of $R^2=0.5906$, above 1.0 ng/mL In the value, $R^2=0.9597$. Second method RT shaking 3hr/2hr was $R^2=0.7262$ less than value of 1.0 ng/mL, $R^2=0.9566$ above than value of 1.0 ng/mL. Third method $37^{\circ}C$ shaking 1hr/1hr was $R^2=0.7728$ less than value of 1.0 ng/mL, $R^2=0.8904$ above than value of 1.0 ng/mL. Forth, Company C's The original method, RT shaking 3hr was $R^2=0.7542$ less than value of 1.0 ng/mL, and $R^2=0.9711$ above than value of 1.0 ng/mL. Fifth method RT shaking 2hr was $R^2=0.5477$ less than value of 1.0 ng/mL, $R^2=0.9231$ above than value of 1.0 ng/mL. Sixth method $37^{\circ}C$ shaking 2hr showed $R^2=0.2848$ less than value of 1.0 ng/mL, $R^2=0.9028$ above than value of 1.0 ng/mL. Conclusion Samples with both values of 1.0 ng/mL or higher in both of the six methods showed relatively high correlation, but the correlation was relatively low less than value of 1.0 ng/mL. Especially, the $37^{\circ}C$ shaking 2hr method of company C showed a sharp fluctuation from the low concentration value of 1.0 ng/mL or less. Therefore, we are planning to continuously test the time, equipment, incubation temperature and so on for the room temperature shaking 2hr method and $37^{\circ}C$ shaking 1hr/1hr of company C which showed a relatively high correlation. After that, we can search for an appropriate shortening method through additional experiments such as recovery test, dilution test, sensitivity test, and provide more accurate and prompt results to the department of medical treatment, It is competitive with EIA test.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.456-459
• /
• 2007

This study was performed for improving the Environmental Conservation Value Assessment Map (ECVAM) of National Land in Korea. The ECVAM items are composed of legal assessment and environmental/ecological assessment. An assessment method applied to ECVAM is basically an overlay method for environmental/ecological assessment items. The purpose of this study is to offer complement items of the ECVAM by examining assessment items. For this, our study was preceded as follows; In this study we assessed the ECVAM by 4 kinds of method. Method I is Comparing overlapping areas of each assessment items Grade 1, 2 and Permission of each assessment items'duplication, Method 2 is Grade 1, 2 areas by only singular assessment items, Method 3 is Only Grade 1 areas of Method 2 and Method 4 is Only Grade 2 areas of Method 2. As results, Method1 showed 93.4% of diameter Grade II(standard for stability), forest diameter item was accounted for 99.9% by Method 2, Method 3 showed 95.7% of forest diameter and forest density was accounted for 66.4% by Method 4. From now on, this study will contribute to reduce the complexity in the process of manufacturing ECVAM of National Land, and to raise the pliability in the process of managing and updating this map.