• Title/Summary/Keyword: Direct calculation

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E/R Stringer Deck Strength Calculation of CSR Bulk Carrier (CSR Bulk Carrier의 E/R Stringer Deck 구조 강도 계산)

  • Choi, Sung-Bin;Kim, Dong-Keun;Kim, Kyoung-Rae
    • Special Issue of the Society of Naval Architects of Korea
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    • 2011.09a
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    • pp.47-50
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    • 2011
  • E/R bulkhead is watertight bulkhead between engine room and cargo hold. So, it must have sufficient strength about cargo load of aft hold. Especially, partial stringer deck between tank top and $2^{nd}$ deck of engine room must have sufficient strength because it has function of primary supporting member. Generally, cargo hold structure is verified through the direct calculation as finite element analysis of cargo hold, but engine room structure doesn't perform it. Therefore, we have performed finite element analysis of engine room stringer deck which considered cargo hold load. And then, it will be able to apply similar ship design.

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BLDC Motor Cogging Torque Calculation with the Moving Material Method in the Finite Element Method

  • Won, Sung-Hong;Choi, Jae-Hoon;Lee, Ju
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.3
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    • pp.74-78
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    • 2008
  • Conventionally, when we need to know about the dynamic characteristics of motors, the moving band method has been the first considerable technique. In this paper, we have investigated the moving material method that moves the property of the material in moving area elements of BLDC motors, instead of moving mesh elements of the rotor. From this method, we can reduce the demanded HDD memory for FEM analysis and the calculation time with same results.

Calculation Precision of the Lighting Simulation Programs - Direct Components (조명시뮬레이션 프로그램의 계산정확도 - 직사성분)

  • Shin, Hyun-Man;Jang, Woo-Jin;Hong, Sung-Wook
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.10a
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    • pp.29-31
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    • 2008
  • For rapid and precise design of lighting, lighting simulation programs are used. For determining the precision of the calculation results of the lighting simulation programs, the illuminance of the specific points are calculated analytically and are compared with the results of the programs by using light sources which have known LDC.

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Dynamic analysis of helicoidal bars with non-circular cross-sections via mixed FEM

  • Eratli, Nihal;Yilmaz, Murat;Darilmaz, Kutlu;Omurtag, Mehmet H.
    • Structural Engineering and Mechanics
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    • v.57 no.2
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    • pp.221-238
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    • 2016
  • One of the objectives of this study is to implement the direct calculation of the torsional moment of inertia for non-circular cross-sections, which is based on the St. Venant torsion formulation and the finite element method. Recently the proposed method provides a unique calculation of the torsional rigidity of simply and multiply connected cross-sections. Next, free vibration analyses of cylindrical and non-cylindrical helices with non-circular cross-sections are solved by a curved two-nodded mixed finite element based on the Timoshenko beam theory. Some thin-thick closed or open sections are handled and the natural frequencies of cylindrical and non-cylindrical helices are compared with the literature and the commercial finite element program SAP2000.

A Second-Order Design Sensitivity-Assisted Monte Carlo Simulation Method for Reliability Evaluation of the Electromagnetic Devices

  • Ren, Ziyan;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • v.8 no.4
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    • pp.780-786
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    • 2013
  • In the reliability-based design optimization of electromagnetic devices, the accurate and efficient reliability assessment method is very essential. The first-order sensitivity-assisted Monte Carlo Simulation is proposed in the former research. In order to improve its accuracy for wide application, in this paper, the second-order sensitivity analysis is presented by using the hybrid direct differentiation-adjoint variable method incorporated with the finite element method. By combining the second-order sensitivity with the Monte Carlo Simulation method, the second-order sensitivity-assisted Monte Carlo Simulation algorithm is proposed to implement reliability calculation. Through application to one superconductor magnetic energy storage system, its accuracy is validated by comparing calculation results with other methods.

Role of London Energy in Determining the C-Dimensions of Phyllosilicates (층상 규산염광물 C-축 결정에 있어서의 런던에너지 역할)

  • 유재영
    • Journal of the Mineralogical Society of Korea
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    • v.3 no.2
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    • pp.89-97
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    • 1990
  • To examine how London energy controls the c-dimensions of phyllosilicates, London energy, as well as Coulomb and Pauli repulstion energy was calculated as a function of d(001) for 1M and d(002) for 2M 1 phyllosilicates. London and Pauli repulstion energy calcualtion use a direct interaction calculation method and Coulomb energy calculation adopts Fourier synthesis method. The energy calculations show that Coulmb and Pauli repulsion energy dominantly control the c-dimensions of phyllosilicates having the interlayer cationss, i.e., the layer charges. On the other hand, if phyllosilicates have no interlayer cations, London energy is solely responsible for holding the layers and maintain the c-dimensions. The significance of London energy in determining the c-dimensions of phyllosislicates de-creases as the layer charge increases. When the layer charge is lower than one equivalent on the basis of Oη(OH)2 formula, London energy plays an important role in determing the c-dimensions. however, if the layer charge is higher than one equivalent, London energy becomes insignifi-cant in determining the c-dimension.

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Development of limit equilibrium method as optimization in slope stability analysis

  • Mendjel, D.;Messast, S.
    • Structural Engineering and Mechanics
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    • v.41 no.3
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    • pp.339-348
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    • 2012
  • The slope stability analysis is usually done using the methods of calculation to rupture. The problem lies in determining the critical failure surface and the corresponding factor of safety (FOS). To evaluate the slope stability by a method of limit equilibrium, there are linear and nonlinear methods. The linear methods are direct methods of calculation of FOS but nonlinear methods require an iterative process. The nonlinear simplified Bishop method's is popular because it can quickly calculate FOS for different slopes. This paper concerns the use of inverse analysis by genetic algorithm (GA) to find out the factor of safety for the slopes using the Bishop simplified method. The analysis is formulated to solve the nonlinear equilibrium equation and find the critical failure surface and the corresponding safety factor. The results obtained by this approach compared with those available in literature illustrate the effectiveness of this inverse method.

A Study of Staffing Estimation for Nursing Manpower Demand in Hospital (병원간호인력의 수요추정에 관한 연구 -환자분류체계에 의한 간호인력 수요추계의 방법을 중심으로-)

  • 김유겸
    • Journal of Korean Academy of Nursing
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    • v.16 no.3
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    • pp.108-122
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    • 1986
  • Changing concepts of health care, are stimulating the demand for health care, thereby orienting society to health care rights to such an extent that they are deemed as fundamental ones inalienable to man. Concomitantly, qualitative as well as quantative improvement is being sought in the nursing service field. Today, efforts are being made in various areas, especially to qualitatively improve nursing services. A second issue concerns proper staffing. It is important to study staffing, in as much as it continues to be the most persistent and critical problem facing hospital nursing administrators today. It involves quantity, quality, and utilization of nursing personnel. A great deal of attention has been focused on this problem since mid 1930's when nursing services began to be felt as an important segment of hospital operation representing the largest single item of hospital budgets. Traditionally, the determination and allocation of nursing personnel resources has relied heavily on gloval approaches which make use of fixed staff-to-patient ratios. It has long been recognized that these ratios are insensitive to variations between institutions and among individual patients. Therefore, the aim of this thesis is to point to the urgent need for the development of methodology and criteria suited to the reality of Korea. The present research selected one place, the W Christian Hospital, and was conducted over a period 10 days from January, and nurses who were them on duty in their unit. The total num-her of patients surveyed was 1,426 and that of 354. The research represents many variables affecting the direct patient care time using the result from the direct observation method, then using a calculation method to estimate the relationship between the patients care time and selected variables in the hospital setting. The amount of direct patient care time varies with many factors, such 89 the patients age. diagnosis and time in hospital. Differences are also found from hospital, clinic to clinic, ward to ward, and even shift to shift. In this research, the calculation method of estimating the required member of nursing staff is obtained by dividing the time of productive patient care activity(with the time of patient care observed), by the sum of the productive time that each the staff can supply, i.e., 360 minutes, which is obtained by deducting the time for personal activities. The results indicate a substantial difference between the time of productive patient care observed directing and the time of the productive patient care estimated using calculating method. If we know accurately the time of the direct patient care on a shift, there required number of staff members calculated if the proper method can be determinded should be able the time of the direct patient care be estimated by the patient classification system, but this research has shown this system to be in accurate in Korea. There are differences in the recommended time of productive patient care and the required number of nursing staff depending upon which method is used. The calculated result is not very accurate, so more research is needed on the patient classification system.

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A Study on Analysis of Construction Monitoring Cost and Improvement Measures of Railway Tunnel Construction in Seoul (서울시 철도터널 건설공사의 공사계측비 분석 및 개선방안 연구)

  • Jong-Tae Woo
    • Journal of the Society of Disaster Information
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    • v.19 no.1
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    • pp.18-30
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    • 2023
  • Purpose: This study is to contribute to the development of monitoring technology through the increase of confidence in construction monitoring by deriving the analysis of construction monitoring cost and improvement measures of railway tunnel construction in Seoul. Method: It presents the status on design and contract of construction monitoring cost, status on application construction monitoring cost and its analysis, analysis on safety management cost and quality management cost, expansion of application of the price calculation standard for monitoring management services to improve this, and monitoring for direct order of ordering organization. Results: If the monitoring management service that was meanwhile ordered as included in the construction work is performed by the directly selected company of ordering organization through the preliminary screening for bidding qualification, then the improvement of monitoring quality and the accurate monitoring data can be secured. Conclusion: For the price calculation standard for monitoring management service, the application of actual cost addition method under the Engineering Promotion Act and the calculation standard of monitoring management cost for standard estimation for ground survey should be extended through the direct order of ordering organization, not the method to be included in the net construction cost where it is performed by a subcontractor via contractor.

An Estimation of Direct and Indirect GHG-AP Integrated Emissions from Energy Sector in Seoul (2010) (서울시 에너지부문 직·간접 온실가스-대기오염 통합 배출량(2010) 산정)

  • Jung, Jaehyung;Kwon, O-Yul
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.2
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    • pp.150-160
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    • 2014
  • Greenhouse gas (GHG) and Air Pollution (AP) emission inventories have been constructed and estimated independently up-to-date in Seoul. It causes difficulty in GHG and AP integrated management due to a difference in emission inventories. In this study, we constructed GHG and AP integrated emission inventories for direct and indirect sources in Seoul during the year 2010 in Energy activities for estimating GHG and AP emissions were derived from IPCC guideline, guidelines for local government greenhouse inventories, air pollutants calculation manual, and Indirect Emission Factors (IEF) reported by Korea Power Exchange. The annual GHG emission was estimated as 50,530,566 $tonCO_{2eq}$, of which 54.8% resulted from direct sources and the remaining 45.2% from indirect sources. Among direct sources, transportation sector emitted the largest GHG, accounting for 47.3% of the total emission from direct sources. As with indirect sources, purchased electricity sector only emitted 98.6% of the total emission from indirect sources. The annual AP emission was estimated as 283,701 tonAP, of which 85.9% was contributed by the combined AP emissions of transportation and fugitive sectors. Estimation of individual air pollutant showed that the largest source were transportation sector for CO, $NO_x$, TSP, $PM_{10}$ and NH3, non-energy sector for $SO_x$, and fugitive sector for VOCs. This study found some limitations in estimating GHG and AP integrated emissions, such as nonconforming emission inventories between GHG and AP, and no indirect AP emission factor of purchased electricity, and so on. Those should be further studied and improved for more effective GHG and AP integrated management.