• 전기학회논문지P
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• 제63권1호
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• pp.12-18
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• 2014

This paper analyzes how to calculate the three phase short circuit current calculation procedures used in the IEC 60909 short circuit. It presented the new procedure of the fault current for the interrupting capacity of the circuit breaker. This procedure is applied to the future power system and calculates the fault current. Power demands are increased because of the growth of the economy for this reason, the fault current of the power system is largely increased and the fault current procedure for the proper interrupting capacity calculation of the existing or the new circuit breaker is essential. How to calculate the three phase short circuit current for ac electrical system and select the high voltage and low voltage circuit breaker based on IEC 60909 standards.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.401-403
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• 2001

This paper presents an advanced calculation method of permissible current capacity on catenary system. If the permissible current calculation method used in electric power system is applied to electric railroad system, it is troublesome. Because electric load in catenary system varies periodically according to time. Therefore, this study proposes permissible current calculation method through heat equation according to time variation.

• Advances in concrete construction
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• 제17권2호
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• pp.75-92
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• 2024

High Strength steel reinforced Reactive Powder Concrete (RPC) Beam is a new type of beams which has evident advantages than the conventional concrete beams. However, there is limited research on the shear bearing capacity of high-strength steel reinforced RPC structures, and there is a lack of theoretical support for structural design. In order to promote the application of high-strength steel reinforced RPC structures in engineering, it is necessary to select a shear model and derive applicable calculation methods. By considering the shear span ratio, steel fiber volume ratio, longitudinal reinforcement ratio, stirrup ratio, section shape, horizontal web reinforcement ratio, stirrup configuration angle and other variables in the shear test of 32 high-strength steel reinforced RPC beams, the applicability of three theoretical methods to the shear bearing capacity of high-strength steel reinforced RPC beams was explored. The plasticity theory adopts the RPC200 biaxial failure criterion, establishes an equilibrium equation based on the principle of virtual work, and derives the calculation formula for the shear bearing capacity of high-strength steel reinforced RPC beams; Based on the Strut and Tie Theory, considering the softening phenomenon of RPC, a failure criterion is established, and the balance equation and deformation coordination condition of the combined force are combined to derive the calculation formula for the shear bearing capacity of high-strength reinforced RPC beams; Based on the Rankine theory and Rankine failure criterion, taking into account the influence of size effects, a calculation formula for the shear bearing capacity of high-strength reinforced RPC beams is derived. Experimental data is used for verification, and the results are in good agreement with a small coefficient of variation.

• 전기학회논문지P
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• 제67권1호
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• pp.15-20
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• 2018

This paper presents the method of ESS energy capacity calculation for stand-alone renewable energy generation system consisting of photovoltaic energy. There is almost no power from photovoltaic system during sunless days. So this source is very weak in terms of the power supply reliability. To improve problem of power supply, battery is mainly used Energy Storage System(ESS). The number of sunless days and Depth of Discharge(DOD) is important factor to determine energy capacity of battery. However, a many study for economical design is required due to the high cost of ESS. In this paper, we propose the new method of ESS energy capacity calculation by applying different DOD for operation with and without sun. We determine the Battery capacity using higher DOD of operation during sunless day than the DOD of the normal operation. And we carried out an economic analysis of the calculation results.

• 한국측량학회지
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• 제23권1호
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• pp.39-47
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• 2005

본 연구에서는 오늘날 해상측량에서 주로 사용되고 있는 DGPS기법과 음향측심기를 조합하여 취득된 해저지형의 3차원 위치정보를 크리깅(kriging), RBF(radial basis function), 최근린(nearest neighbor) 보간법을 이용하여, 항만공사에서의 호퍼준설량을 산정하였다. 또한, 각각의 보간법에 의해 산정된 호퍼준설량과 실제 준설량을 비교·분석함으로써, 준설량 산정에 있어 DGPS/Echo Sounder 기법의 활용성을 확인할 수 있었다. 그 결과, 크리깅 보간법을 적용한 경우 내용적 차이는 15,364㎥로 약 1.89%의 오차율을 나타내었으며, RBF 보간법과 최근린 보간법을 적용한 경우에는 각각 3.9%, 4.4%의 오차율을 나타내었다. 향후, 항만공사에서의 준설량 산정에 있어서 해저지형의 특성에 따른 적합한 보간법 적용에 관련한 연구가 선행될 경우, 보다 신속하고 정확한 준설량을 산정 할 수 있을 것으로 기대된다.

• 대한조선학회논문집
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• 제46권1호
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• pp.78-86
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• 2009

A capacity calculation and process analysis is a very important part for the entire ship production planning. Ship's production plan is set up with a concept that the product is produced based on the capacity achievable by the processes while general manufacturing sets up the production plan based on product lead-time. Therefore, in case the calculation of capacity for each process of shipbuilding yard is different from actual conditions, a series of production plan - ship table composition, dual schedule plan and execution schedule plan, etc - may accumulate errors, lose reliability of planning information and cause heavy cost deficit in this course. In particular, in case of new shipbuilding yard, stocks between processes are built up and half blocks are not supplied in timely manner, and that is sometimes due to the clumsiness of the operator but it is more often because of the capacity to execute each process is not logically calculated. Therefore, this paper presents the process to calculate the assembly leadtime and assembly process capacity for shipbuilding yard assembly factory. This paper calculated the block type for calculation of assembly lead time based on block DAP(detailed assembly procedure), and introduced cases that calculate production capacities by assembly surface plate by considering the surface plate occupied area of the blocks that change depending on assembly field area and assembly processes through assembly simulation.

• 한국해양공학회지
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• 제20권3호
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• pp.67-76
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• 2006

Three-dimensional information of submarine topography was acquired by assembling DGPS and Echo Sounder, which is mainly used in the marine survey. However, the features of submarine topography, derived according to mechanical data, were confirmed using human eyes. Because the dredging capacity using a submarine surveying data influences harbor public affairs, analysis and the process method of surveying data is a very special element in construction costs. In this study, information on submarine topography is acquired by assembling DGPS and Echo Sounder. Moreover, the dredging capacity in harbor public affairs has been analyzed by the interpolation method: inverse distance to a power, kriging, minimum curvature, nearest neighbor, and radial basis function. Also, utilization of DGPS and Echo Sounder method in calculation of the dredging capacity have been confirmed by comparing and analyzing the dredging capacity and the actual one, as per each interpolation. According to this comparison result, in the case of applying Radial basis function interpolation and Kriging, 3.94 % and 4.61 % of error rates have been shown, respectively. In the case of the study for application of the proper interpolation, as per characteristics of submarine topography, is preceded in calculation of the dredging capacity relevant to harbor public affairs, it is expected that more speedy and correct calculation for the dredging capacity can be made.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.585-592
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• 2002

Discharge capacity of PBD is the most important factor of specification items to control any product of PBD. There is no standard specification for the PBD. Because the degree of discharge capacity is related to well resistance, install depth, maximum strain etc in the field. Discharge capacity test of PBD, permeability test of filter are conducted using PBD materials used in Korea. This paper proposes the critical discharge capacity for deep PBD under condition of non well resistance based upon their test and theoretical calculation. It was found that discharge capacity more than about 10 ㎤/sec is enough to undergo designing of deep PBD without well resistance.

• 한국산학기술학회논문지
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• 제6권5호
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• pp.396-400
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• 2005

소규모 독립형 태양광발전시스템의 안정적인 설계를 위해서는 태양전지와 배터리 용량이 매우 중요한 요소이다. 태양전지 및 배터리의 용량산정이 잘못되면 시스템의 동작이 불안정해지고 잦은 고장의 원인이 된다. 따라서 본 논문에서는 안정적인 태양광발전시스템의 설계를 위해 부하특성을 고려한 태양전지와 배터리 용량산정 방안을 제시하였다.

• Earthquakes and Structures
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• 제22권1호
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• pp.39-51
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• 2022

The axial compression behavior of nine self-compacting concrete columns confined with CFRP-PVC spirals was studied. Three parameters of spiral reinforcement spacing, spiral reinforcement diameter and height diameter ratio were studied. The test results show that the CFRP strip and PVC tube are destroyed first, and the spiral reinforcement and longitudinal reinforcement yield. The results show that with the increase of spiral reinforcement spacing, the peak bearing capacity decreases, but the ductility increases; with the increase of spiral reinforcement diameter, the peak bearing capacity increases, but has little effect on ductility, and the specimen with the ratio of height to diameter of 7.5 has the best mechanical properties. According to the reasonable constitutive relation of material, the finite element model of axial compression is established. Based on the verified finite element model, the stress mechanism is revealed. Finally, the composite constraint model and bearing capacity calculation method are proposed.