• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.6 no.2
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• pp.54-60
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• 2010

Piping failures due to thermal fatigue have been widely reported in normally stagnant non-isolable reactor coolant branch lines. Since the thermal fatigue due to thermal stratification was not considered in the piping fatigue design in old NPPs, it is important to evaluate the effect of thermal stratification on the integrity of branch lines. In this study, geometrical screening criteria for Up-horizontal branch lines in MRP-132 were applied to SI(Safety Injection) lines of KSNP 2-loop and WH 3-loop. Some computational fluid dynamic(CFD) analyses on the Reactor Coolant System(RCS) branch lines were also performed to develop the regulatory guidelines for screening criteria. As a result of applying MRP-132 screening criteria, KSNP 2-loop and WH 3-loop SI lines are determined to need further detailed evaluation. Results of CFD analyses show that both valve isolation and amount of leakage through valve can be used as technical bases for the screening criteria on the thermal fatigue analysis.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.148-150
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• 2006

This paper describes the overvoltage at the branch line in underground distribution systems when the direct lightning surge strikes on conductor of overhead line. Distribution systems are very complex because it includes many branch lines, transformers, switches and so on. Therefore model system consists of overhead distribution lines, underground cable include branch lines, lightning source and switches. Analysis are performed using EMTP to understand and evaluate the surge behavior on branch lines considering various conditions in underground distribution systems. Simulation results show overvoltage with location in various cases. It is evaluated that result will be used to establish protection methods in actual underground distribution systems.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.5
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• pp.110-119
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• 2009

In this study magnetic fields near electric power lines with branch lines which have a arbitrary angle were derived and formulated by dipole antenna theory and could be calculated easily using the formula. It seems that those formula could be applicable to the consideration of magnetic fields during the design of distribution lines with branch lines. As an example those formulated equations on elements of magnetic fields were applied to a model of 3 phase distribution lines with branch lines and calculated by Matlab programs and the results were presented The analyzed results are follows. The resultant magnetic field is dominated by the componant By all over y-axis in the case of the smaller branched angle $\alpha$ and the lower observed point z. In case of ${\alpha}=\frac{\pi}{2}$[rad], the resultant field is affected by the componant Bx. The resultant field is dominated by the componant Bz at the vicinity of the power lines and it shows very large value at the branch line position of y-axis in case of ${\alpha}>\frac{\pi}{2}$.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.685-687
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• 2005

In this study, near the 3-phase power lines with branch lines were formulated. In rectangular coordinates, dependence of branch angle $\alpha$ on electromagnetic field components $B_x,\;B_y,\;B_z$ 및 $E_x,\;E_y,\;E_z$ was analyzed. The resultant electromagnetic fields B and E were discussed.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.157-158
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• 2006

This paper describes the overvoltage of branch line in underground distribution systems when the direct lightning surge strikes on conductor of overhead line. Distribution systems are very complex because that includes so many branch lines, transformers, switches and so on. Therefor model systems consist of overhead distribution lines, underground cable include branch lines, lightning source and switches. Those are established by EMTP/ATPDraw. Simulation analyzes surge behavior on branch lines considering various conditions in underground distribution systems. Simulation results shoe overvoltage with location in various cases.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1754-1763
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• 2017

This paper analyses the characteristics of incomplete-journey double-circuit transmission lines on the same tower formed by single-circuit lines and double-circuit lines, and then presents a fault location algorithm based on identification of fault branch. With the relationship between the three-phase system and the double-circuit line system, a phase-mode transformation matrix for double-circuit lines can be derived. Based on the derived matrix, the double-circuit lines with faults can be decoupled, and then the fault location for an incomplete-journey double-circuit line is achieved by using modal components in the mode domain. The algorithm is divided into two steps. Firstly, the fault branch is identified by comparing the relationships of voltage amplitudes at the bonding point. Then the fault location, on the basis of the identification result, is calculated by using a two-terminal method, and only the fault distance of the actual fault branch can be obtained. There is no limit on synchronization of each terminal sampling data. The results of ATP-EMTP simulation show that the proposed algorithm can be applied within the entire line and can accurately locate faults in different fault types, fault resistances, and fault distances.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.94-94
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• 2017

Oryza sativa and Oryza glaberrima are rice cultivars distributed in Asia and Africa. There are several differences between these cultivars in morphological characteristics such as panicle structure and especially the secondary branch number of O. glaberrima is less than that of O. sativa. Generally, branch number of panicle related to a large vascular bundle number (VBN) among O. sativa and there is a wide variation of the VBN of the peduncle from where the bundles enter into the rachis branches. However, there is less information about VBN in O. glaberrima and also the relationship between VBN and branch numbers, the primary branch number (PBN) and secondary branch number (SBN). Additionally, the genetic factor for VBN and branch number in O. glaberrima is not completely exploited. In this study, phenotypic variation for VBN and panicle structure were investigated using a set of 40 $BC_3$ -derived from IRGC 104038 (O. glaberrima from Senegal) and 35 $BC_4$ -derived from IRGC103777 (O. glaberrima from Mali) introgression lines with a genetic background of japonica rice Taichung 65. Taichung 65 had 11.8 PBN, 16.0 SBN and 11.5 VBN, while IRGC 103777 had 12.0 PBN, 15.0 SBN and 15.3 VBN. The introgression lines derived from IRGC 104038 had range from 9.0 to 14.4 in the PBN, range from 9.6 to 33.5 in the SBN and range from 9.8 to 14.8 in the VBN. Additionally, the introgression lines derived from IRGC 103777 had range from 9.0 to 18.5 in the PBN, range from 10.3 to 39.0 in the SBN and range from 9.0 to 15.3 in the VBN. Among two set of introgression lines, there are significant correlation between VBN and PBN. Multiple introgression lines indicated higher PBN, SBN and VBN than Taichung 65 and these examined characteristics are supposedly controlled by quantitative traits loci. The genetic factor related to VBN and panicle architecture can be revealed using segregating population in future study.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.286-291
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• 2011

Directional couplers are widely used in RF and microwave applications to distribute or monitor signals. This paper presented a new structure of microstrip branch line directional coupler with coupled lines. The loose couplings of microstrip branch line directional couplers are impractical for the high characteristic impedance values required for the shunt branches. To overcome this limitation, the parallel coupled lines with the shorts were used for the high characteristic impedance. The results of the simulations and measurements were presented for the proposed branch line directional coupler. Measurement of the 10 dB branch line directional coupler shows that the return loss is higher than 30 dB over 10 % bandwidth and the isolation is 35 dB or better over 8 % bandwidth.

• Journal of Radiation Industry
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• v.4 no.3
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• pp.215-219
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• 2010

We have subjected to gamma-irradiation to citrus buds and then grafted onto mature citrus tree. Mutant citrus branch lines have been induced. As a result of first selection, we found the several mutant lines showing interesting phenotypes such as higher sugar content. We have selected several branches showing good qualities such as higher sweetness and/or lower acidity. Some branch lines showed over $13^{\circ}Brix$ sugar content and below 0.9% acidity. Other mutant branch lines showed the changes of shape, size, peel thickness, and fiber contents or distribution of fruits. The results suggest that gamma-irradiation is an effective tool for induction of citrus mutant lines.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.6
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• pp.598-604
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• 2011

A method of miniaturizing branch line coupler with connected coupled lines is presented. The quarter-wavelength transmission lines in the typical microstrip branch line coupler are replaced with the connected coupled lines with same characteristics of ones for compact size. The connected coupled line is analyzed by T-equivalent circuit and Z parameters based on the even-odd mode analysis. The proposed branch line couplers with connected coupled line are designed and fabricated on FR4 substrate at 2.4 GHz. The measured results show good agreement with theoretical prediction. And the experimental results show that the size of coupler is 37 precent smaller than conventional coupler. This minimized coupler is suitable for Butler Matrix as feeder for mobile communication beam forming antenna.