• Title/Summary/Keyword: Calculation

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Fire design of concrete encased columns: Validation of an advanced calculation model

  • Zaharia, R.;Dubina, D.
    • Steel and Composite Structures
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    • 제17권6호
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    • pp.835-850
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    • 2014
  • The fire resistance of composite steel and concrete structures may be determined by using the simplified methods provided in EN 1994-1-2. For the particular situations not covered by the standard, an advanced calculation model might be applied, using special purpose programs for the analysis of structures in fire. The validation of these programs has always been an important issue for software developers, but also for designers and authorities. Clause 4.4.4 from EN 1994-1-2 refers to the validation of the advanced calculation models and states that these models must be validated through relevant test results. The paper presents the calculation of fire resistance of the composite columns in a high-rise building built in Romania, and focusses on the validation of the calculation model (computer program SAFIR), for this particular case. This validation, asked by the Romanian authorities, considers the available experimental results of a fire test, performed on a similar composite steel-concrete column.

750kW급 직접구동형 풍력발전기의 부하계산 (Load Calculation of a 750 kW Direct-drive Wind Turbine Generator System)

  • 손영욱;박인수;권세진;김영찬;손정봉;김경렬;정진화;전중환;류지윤
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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    • pp.649-655
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    • 2003
  • Load calculation is indispensable for the construction of a large wind turbine generator system (WTGS). In procedures of load calculation, all conditions affecting to WTGS such as environment of site, operation, transport and installation have to be considered systematically. So the certification of WTGS is issued by assuring the load calculation. This work shows the generals of load calculation briefly and introduces the characteristics and results of load calculations for the 750 kW direct-drive WTGS (KBP-750D) which is under development by the consortium of POSTECH and UNISON.

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상수관망에서 누수탐지를 위한 역추적계산법 (Back Tracing Calculation Method for the Leakage Detection in Water Distribution System)

  • 권혁재
    • 상하수도학회지
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    • 제27권5호
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    • pp.611-619
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    • 2013
  • In this study, Back Tracing Calculation Method was developed to determine the leakage location and leakage amount. Previously developed determination method of monitoring location and newly developed Back Tracing Calculation Method were applied to the sample pipe network and real size pilot plant. After leakage was assumed in the pilot plant, leakage location and leakage amount could be traced by Back Tracing Calculation Method. From the results, it was found that Back Tracing Calculation Method can be applied for the leakage detection in water distribution system. Furthermore, this method can be applied for the pressure management or leakage detection as a pressure control method in water distribution system.

식품섭취 조사 분석시 영양가 계산 프로그램의 비교 연구 (Comparison of Nutrient Calculation Programs for Dietary Intake Analysis)

  • 문현경;김은경
    • 대한영양사협회학술지
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    • 제5권1호
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    • pp.100-115
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    • 1999
  • With the growing number of nutrient calculation software packages on the market, there are need to compare each programs. Since each program use different nutrient databases, the result of calculation may be different in value. In this study, we use three(A, B, C) most popular program package to compare the result of nutrient calculation. For the analysis, 24hour recall data from 97 preschool children, 66 university students and 95 aged persons were used. For the calculation if subjects gave the complete recipe, recipes from the subjects were used. Otherwise, recipe from the program database were used. Common 15 nutrients of which all program can give results, are analyzed and compared for mean nutrient intake and nutrient intake for food groups. Ten nutrients among 15 nutrients which have RDA were analyzed for % of RDA and the distribution of RDA. Mean nutrient intake of Fe, vitamin A, Na were statistically different among results of the calculation using three programs(p<0.001). The distribution of Fe, vitamin A and vitamin $B_2$, niacin were statistically different among three results of the calculation using three program(p<0.001, p<0.05). Nutrient intakes of food groups were statistically different in cereal and products, bean and products, vegetables, fruits, fishes and shellfishes, milk and products, beverages, and seasonings(p<0.0001). It is hard to say that the difference among three program are coming from the difference from nutrient database or recipe database in this study. With these result, we conclude that it is necessary to evaluate nutrient database and recipe database as the foremost consideration in selecting nutrient calculation software. Those differences should be considered when interpreting results, comparing results with other studies, and when developing treatment plans in the clinical settings.

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6 MV X-선 빔을 사용하는 치료실에 설치되는 직접 차폐식 도어의 차폐 두께 계산식 (Calculation Formula for Shielding Thickness of Direct Shielded Door installed in Treatment Room using a 6 MV X-ray Beam)

  • 박철서;김종언;강은보
    • 한국방사선학회논문지
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    • 제14권5호
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    • pp.545-552
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    • 2020
  • 이 연구의 목적은 NCRP 보고서 151과 IAEA 안전 보고서 시리즈 47 기반으로 직접차폐식 도어의 납 두께 계산식을 유도하는 데 있다. 직접차폐식 도어에서 선량률 계산식을 유도한 후, 이 식을 납 차폐 두께 계산식에 대입하여 도어에서 차폐 두께 계산식을 유도하였다. 유도된 직접차폐식 도어의 차폐 두께 계산식으로부터 계산된 납 차폐 두께는 NCRP 및 IAEA 2차 방벽 차폐 두께 계산 방법으로 산출된 두께보다 약 6% 낮았다. 이 결과는 NCRP 및 IAEA 2차 방벽 차폐 두께 계산 방법으로부터 두께 계산이 더 보수적이고 2차 빔 차폐에 잘 맞는다는 의미로 해석된다. 결론적으로, 이 연구에서 유도된 직접차폐식 도어의 납 차폐 두께 계산식은 도어의 차폐 설계에 유용하게 사용될 수 있을 것으로 사료된다.

History of the Photon Beam Dose Calculation Algorithm in Radiation Treatment Planning System

  • Kim, Dong Wook;Park, Kwangwoo;Kim, Hojin;Kim, Jinsung
    • 한국의학물리학회지:의학물리
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    • 제31권3호
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    • pp.54-62
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    • 2020
  • Dose calculation algorithms play an important role in radiation therapy and are even the basis for optimizing treatment plans, an important feature in the development of complex treatment technologies such as intensity-modulated radiation therapy. We reviewed the past and current status of dose calculation algorithms used in the treatment planning system for radiation therapy. The radiation-calculating dose calculation algorithm can be broadly classified into three main groups based on the mechanisms used: (1) factor-based, (2) model-based, and (3) principle-based. Factor-based algorithms are a type of empirical dose calculation that interpolates or extrapolates the dose in some basic measurements. Model-based algorithms, represented by the pencil beam convolution, analytical anisotropic, and collapse cone convolution algorithms, use a simplified physical process by using a convolution equation that convolutes the primary photon energy fluence with a kernel. Model-based algorithms allowing side scattering when beams are transmitted to the heterogeneous media provide more precise dose calculation results than correction-based algorithms. Principle-based algorithms, represented by Monte Carlo dose calculations, simulate all real physical processes involving beam particles during transportation; therefore, dose calculations are accurate but time consuming. For approximately 70 years, through the development of dose calculation algorithms and computing technology, the accuracy of dose calculation seems close to our clinical needs. Next-generation dose calculation algorithms are expected to include biologically equivalent doses or biologically effective doses, and doctors expect to be able to use them to improve the quality of treatment in the near future.

녹지의 산출방법이 습도변화에 미치는 영향 (Humidity Variation by Green Space Calculation Method)

  • 윤용한;박헌
    • 아시안잔디학회지
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    • 제16권1호
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    • pp.41-47
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    • 2002
  • 본 연구는 녹지의 계층구조 등이 다양한 도시녹지를 대상으로 그 산출방법이 습도변화에 미치는 영향을 정량적으로 파악하기 위해 녹지내의 습도분포를 관측하였다. 그 데이터를 바탕으로 녹지의 토지피복현황과 습도분포, 식재의 산출방법과 습도, 식재의 계층구조의 산출방법과 습도와의 관련성을 회귀분석 등에 의해 해석하였다. 그 결과, 토지피복현황뿐만 아니라 녹지의 산출방법이 습도변화에 많은 영향을 미치고 있다. 또한, 식재율(평면적) 및 식재량(입체적)의 증가는 습도상승에 효과적이다. 더욱이 계층구조가 다양한 식재를 대상으로 그 산출방법과 습도상승과의 관계를 회귀계수와 상관계수를 통해 비교하면, 식재를 산출할 경우에는 평면적인 방법보다 입체적인 방법이 습도상승에 미치는 효과(수치)가 컸다. 앞으로 습도상승효과의 지표로서 식재의 산출은 입체적인 방법의 활용을 제안한다.

Ship Stability Calculation for Cause Analysis of No. 501 Oryong Sinking Accident

  • Lee, Sang-Gab;Lee, Jae-Seok;Ki, Jee-Hun
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2018년도 추계학술대회
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    • pp.248-255
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    • 2018
  • Deep-sea fishing vessel No. 501 Oryong was fully flooded through the openings and was sunk down to the bottom of sea due to the very rough sea weather on the way of evasion after fishing operation in the Bearing Sea with many crews dead and/or missed. In this study, calculation of ship stability was carried out using KST-SHIP(ship calculation system of KST), considering the effect of flow fluid and fish catch arrangement according to the progress of its sinking accident, and damage stability was analyzed. For this study, intact stability calculation of its accident ship under the full load departure condition and its calculation result were verified by comparing with each other, and intact stability according to displacement from the departure of accident ship just before the accident was calculated and analyzed. Damage stability was calculated according to the progress during sinking accident and also analyzed.

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DDA를 이용한 하드웨어 보간기의 계산효율 향상에 관한 연구 (A study on the improvement of calculation efficiency for the two-axis hardware interpolator using DDA)

  • 오준호;최기봉
    • 대한기계학회논문집
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    • 제12권5호
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    • pp.968-975
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    • 1988
  • 본 연구에서는 직선보간과 원호보간에서 계산효율을 향상시킬 수 있는 방법을 제시하여 이 방법과 가감속 구간을 고려한 하드웨어 보간기를 설계 및 제작하였고, 이 것을 스텝 모터에 의해 구동되는 밀링머시인에 연결하여 보간기의 성능을 알아보았다.

Verification of neutronics and thermal-hydraulic coupled system with pin-by-pin calculation for PWR core

  • Zhigang Li;Junjie Pan;Bangyang Xia;Shenglong Qiang;Wei Lu;Qing Li
    • Nuclear Engineering and Technology
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    • 제55권9호
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    • pp.3213-3228
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    • 2023
  • As an important part of the digital reactor, the pin-by-pin wise fine coupling calculation is a research hotspot in the field of nuclear engineering in recent years. It provides more precise and realistic simulation results for reactor design, operation and safety evaluation. CORCA-K a nodal code is redeveloped as a robust pin-by-pin wise neutronics and thermal-hydraulic coupled calculation code for pressurized water reactor (PWR) core. The nodal green's function method (NGFM) is used to solve the three-dimensional space-time neutron dynamics equation, and the single-phase single channel model and one-dimensional heat conduction model are used to solve the fluid field and fuel temperature field. The mesh scale of reactor core simulation is raised from the nodal-wise to the pin-wise. It is verified by two benchmarks: NEACRP 3D PWR and PWR MOX/UO2. The results show that: 1) the pin-by-pin wise coupling calculation system has good accuracy and can accurately simulate the key parameters in steady-state and transient coupling conditions, which is in good agreement with the reference results; 2) Compared with the nodal-wise coupling calculation, the pin-by-pin wise coupling calculation improves the fuel peak temperature, the range of power distribution is expanded, and the lower limit is reduced more.