• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.5
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• pp.684-691
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• 1999

A load calculation program based on TFM(Transfer function method) has been proposed in this study. The validity of the current method has been verified by comparing heat gain calculation by TRF(Thermal response factor) with that by CTF(Conduction transfer function) adopted in ASHRAE. In addition, it seems that the CTF coefficients given in ASHRAE tables have somewhat ambiguity The load calculation program developed in the current study has been employed to calculate cooling load from the exterior walls and roof of example 6 in the ASHRAE. The results are found in good agreement.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.30-43
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• 2021

In the 2D/1D method, a global adjoint CMFD based on the generalized equivalence theory is built to synthesize the 2D radial MOC adjoint and 1D axial NEM adjoint calculation and also to accelerate the iteration convergence of 3D whole-core adjoint transport calculation. Even more important, an advanced yet accurate two-level (TL) CMFD acceleration technique is proposed, in which an equivalent one-group adjoint CMFD is established to accelerate the multi-group adjoint CMFD and then to accelerate the 3D whole-core adjoint transport calculation efficiently. Based on these method, a new code is developed to perform 3D adjoint neutron flux calculation. Then a set of VERA and C5G7 benchmark problems are chosen to verify the capability of the 3D adjoint calculations and the effectiveness of TL CMFD acceleration. The numerical results demonstrate that acceptable accuracy of 2D/1D adjoint calculations and superior acceleration of TL CMFD are achievable.

• Journal of Advanced Marine Engineering and Technology
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• v.3 no.1
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• pp.2-18
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• 1979

Due to increasing ship dimensions and installed propulsive power, resonance frequencies of the propeller shaft system tend to decrease and they can appear in some cases within the operating range of the shaft revolution. For calculation of transverse shaft vibrations, various methods have been proposed but as they are mainly for approximate calculation, no contented results are obtained. For fairly accurate estimation of resonance frequencies in the design stage, one can use transfer matrix method of the finite element method and former is rather prefered in ordinary cases. In this study, the finite element method which is utilized for calculation of the propulsion shaft alignment, is introduced to derive the vibration equation of the ship's propulsion shaftings. The digital computer program is developed to solve the above equation, and the details of preparing the input data are described. The method presented in the underlying report was applied to the shafting of ship which has a lignumvitae bearing to verify its reliability and the results of calculation and those of the measurements on rotating shaft show a good agreement. Calculating methods of exciting of forces and damping forces are also discussed for future work.

• 전기의세계
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• v.29 no.5
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• pp.329-335
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• 1980

This paper presents the reliability calculation method in power supply for a part of the power system reliability control. This method involves assuming several systems that can meet the demands, accidents on the transmission facilities and power source and performing the load flow calculation which will lead to the demands which are not served, frequency of the not-served demands and mean value of the not-served demands. In this study the simplified method for reliability calculation by using the maximal flow problem was developed. The results demonstrate the remarkable advantages and more useful than any other methods for the practical applications.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.391-393
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• 1997

Two kinds of the calculation technique are Investigated with 3D triangular SCM for the arrangement of the dielectric sphere with different resistivity under a uniform electric field. The calculation error of Method I is small outside the sphere, but considerably high Inside. On the other hand, the accuracy is much Improved even Inside the solid dielectric by Method II, which uses double layers of triangular charges on the dielectric boundary.

• Solar Energy
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• v.19 no.3
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• pp.53-61
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• 1999

We already presented new calculation method about the temperature distribution in hot water pipe flow of the unsteady condition. In this paper, we introduce consequence of the case study to confirm appropriation of the calculation method, and case study performs to establish actual hot water use supposed two model that is; the CWV(constant water volume) and VWV(variable water volume).

• Solar Energy
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• v.19 no.3
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• pp.13-21
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• 1999

Calculation method about the water temperature variable inside hot water pipe had proposed in the past does not correspond with branch pipe system, variable of water volume, variable of entrance water temperature, using and so on. A calculation method proposed in this paper can solve above problems, and calculate the kinds variation of the water temperature inside pipe in the real use state of the hot water pipe.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.3
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• pp.274-285
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• 2021

Objectives: The question of whether the level of fees paid to working environment measurement agencies is appropriate has long been a matter of concern to the government. In addition, measurement institutions express dissatisfaction with their level of compensation, which has a great influence on the evaluation of a subject's policy. This study is intended to find a way to appropriately calculate working environment measurement fees. Methods: We looked at the principle of fee determination as a basic theory of fee calculation used in fee calculation, the legal and academic aspects of the general method of fee calculation, and government cost calculation standards. Furthermore, we reviewed the research methods applied so far to derive a method of calculating fees appropriate for this environment. Results: The working environment measurement environment is different from other commission calculation environments. The other environment is to appropriately calculate the service price provided by a monopoly public enterprise, while the situation is to appropriately calculate the fees provided by competitive private enterprises. Therefore, the service delivery environment and the delivery entity are different. In this case, the appropriate method of calculating service fees would be competitive pricing. There have also been many problems under the method of calculation by service cost. Conclusions: First, the working environment measurement fee requires an accounting correction of endogenous variables. Second, the theory of calculating fees appropriate for this situation is appropriate for competitive pricing that applies to private competitors. Third, the government should make efforts to make the service supply market a fully competitive market while ensuring that the service fee level is determined at the marginal cost level. Fourth, economically, research on marginal cost levels is needed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1633-1638
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• 2016

Loop system arrangement in the primary distribution system has been increased for higher reliability of power supply to the customer. This paper presents a new fault calculation method for the loop structured unbalanced distribution feeders. Mathematical modeling method of the distribution system and superposition principal based fault calculation procedures are provided. In order to establish feasibility of the proposed method, various case studies have been performed using Matlab power system toolbox.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1387-1395
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• 2016

A method for the identification of mechanical parameters based on integral calculation is presented. Both the moment of inertia and the friction constant are identified by the method developed here, which is based on well-known mechanical differential equations. The mechanical system under test is excited according to a pre-determined low-frequency sinusoidal motion, minimizing the distortion, and increasing the accuracy of the results. The parameters are identified using integral calculation, increasing the robustness of the results against measurement noise. Experimental data are supported by simulation, confirming the effectiveness of the proposed technique. The performance improvements shown here are of use in the design of speed and position controllers and observers. Owing to its simplicity, this method can be readily applied to commercial inverter products.