• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1355-1363
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• 2015

In order to maintain customer voltage within allowable limit($220{\pm}13V$), tap operation of SVR(step voltage regulator) installed in primary feeder could be carried out according to the scheduled delay time(30 sec) of SVR. However, the compensation of BESS(battery energy storage system) is being required because the customer voltages during the delay time of SVR have a difficultly to maintain within allowable limit when PV system is interconnected with primary feeder. Therefore, this paper presents modeling of SVR to regulate voltage with the LDC(line drop compensation) method and modeling of BESS to control active and reactive power bi-directionally. And also, this paper proposes the coordination control modeling between BESS and SVR in order to overcome voltage problems in distribution system. From the simulation results based on the modeling with the PSCAD/EMTDC, it is confirmed that proposed modeling is practical tool for voltage regulation analysis in distribution system.

• The KIPS Transactions:PartB
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• v.19B no.2
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• pp.123-126
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• 2012

This paper proposed a method to separate a liver into left and right liver lobes for simple and exact volumetry of the river graft at abdominal MDCT(Multi-Detector Computed Tomography) image before the living donor liver transplantation. A medical team can evaluate an accurate river graft with minimized interaction between the team and a system using this algorithm for ensuring donor's and recipient's safe. On the image of segmented liver, 2 points(PMHV: a point in Middle Hepatic Vein and PPV: a point at the beginning of right branch of Portal Vein) are selected to separate a liver into left and right liver lobes. Middle hepatic vein is automatically segmented using PMHV, and the cutting line is decided on the basis of segmented Middle Hepatic Vein. A liver is separated on connecting the cutting line and PPV. The volume and ratio of the river graft are estimated. The volume estimated using 2 points are compared with a manual volume that diagnostic radiologist processed and estimated and the weight measured during surgery to support proof of exact volume. The mean ${\pm}$ standard deviation of the differences between the actual weights and the estimated volumes was $162.38cm^3{\pm}124.39$ in the case of manual segmentation and $107.69cm^3{\pm}97.24$ in the case of 2 points method. The correlation coefficient between the actual weight and the manually estimated volume is 0.79, and the correlation coefficient between the actual weight and the volume estimated using 2 points is 0.87. After selection the 2 points, the time involved in separation a liver into left and right river lobe and volumetry of them is measured for confirmation that the algorithm can be used on real time during surgery. The mean ${\pm}$ standard deviation of the process time is $57.28sec{\pm}32.81$ per 1 data set ($149.17pages{\pm}55.92$).