• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.828-830
• /
• 2009

In Korea, various efforts to cope with the Post-Kyoto system have been recently performed because a duty for the GHG(Greenhouse Gas) reduction may be allocated from 2013. Especially, the role of railroad has been strengthened to decrease total GHG emission of transportation system. Therefore, it is necessary to investigate the GHG emission and the reduction strategies of railroad. The purpose of this study was to develop the calculation method of GHG emission released from railroad. Main source of GHG emission was the energy consumption of railroad vehicle and infrastructure. Based on the emission factor and the equation reported in IPCC 2006 guideline, the total GHG emission of railroad was about 1.4 million tons CO2e in 2007. Using this calculation method, the GHG data of railroad can be calculated quantitatively and managed systematically in the future.

• East Asian mathematical journal
• /
• v.24 no.5
• /
• pp.431-464
• /
• 2008

In this paper, we investigate reduction and four rules of fractional calculation on GuJangSulHae and the other Sanhakseo, and elementary school mathematics education.

• Journal of Advanced Marine Engineering and Technology
• /
• v.22 no.3
• /
• pp.328-336
• /
• 1998

Marine reduction gears are usually used to increase the propulsion efficiency of propellers for ships powered by medium and small sized high speed diesel engines. Most of shaft systems adopt flexible couplings to absorb the transmitted vibratory torque from the engines to the reduction gears and to prevent the chattering phenomenon of reduction gears. However some elastic couplings show non-linear characteristics due to the variable torque transmitted from the main engines and the change of ambient temperature. In this study dynamic characteristics of flexible couplings sare investigated and their effects upon various vibratory conditions of propulsion systems are clarified. A calculation program of torsional vibration for the propulsion systems are clarified. A calculation program of Results of the program developed are compared with ones of the existing linear method and propulsion systems with the elastic couplings the transfer matrix method is adopted which is found to give satisfied results.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.790-795
• /
• 2011

When railway crossing is required to be improved to improve road traffic efficiency, cost-benefits analysis is conducted. In the analysis, such benefits as the reduction of the delay in road vehicle traffic and related costs and reduction of traffic accidents have been appropriately estimated, however, which has not been the case for the reduction of railway operation costs and accidents. This omission may result in a significant difference in the total estimation of the benefits achievable in a long railway line where many of the crossings are improved or reconstructed. This would deteriorate the rationality of the benefit analysis. As the result, although there are various, significant benefits recognizable in the improvement of railway crossings, but they have not been included in the list of the benefits due to the difficulty in calculation. To this end, this paper proposes a methodology of the calculation of the benefits of railway crossing improvement by estimating the unit costs used in the estimation of the benefits obtainable by the reduction of the railway operation costs and the reduction of the accidents at a crossing on the basis of past studies and data.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.10 s.101
• /
• pp.995-1002
• /
• 2005

An orthogonal frequency division multiplexing(OFDM) system has the problem of the peak-to-average power ratio(PAR). In general, in order to obtain optimal PAR reduction using the partial transmitted sequence(PTS), the total search for the number of sub-blocks and the rotation factors must be accomplished. As the number of sub-blocks and rotation factors increases, PAR reduction improves, such that complexity increases exponentially and the process delay occurs simultaneously. Therefore a technique that reduces PAR, which is almost close to optimal, and the amount of calculation is desired. In this paper a new method using genetic algorithm(GA), which is widely used to search for a point that is globally optimal in many problems, is proposed to search for a rotation factor that reduces simultaneously both the PAR and the amount of calculation, such that the complexity of calculation and the process time are reduced at the same time, Comparison is performed between the proposed method and the various techniques developed previously. The superiority of proposed method is presented by demonstrating the reduction of complexity while a similar PAR reduction is obtained.

• Proceedings of the KIEE Conference
• /
• 1997.07c
• /
• pp.1074-1077
• /
• 1997

Newton-Raphson method is mainly used since it shows remarkable convergence characteristics. It, however, needs considerable calculation time in construction and calculation of inverse Jacobian matrix. In this paper a new type of load flow equation is summarized as follows: Since inverse calculation of Jacobian matrix is not needed in the suggested algorithm but using complex bus voltage, the calculation process is simple. With the simple structure, reduction of calculation time is achieved.

• Journal of Adhesion and Interface
• /
• v.7 no.4
• /
• pp.60-64
• /
• 2006

In modern vehicle construction the search for means of weight reduction, improving durability, increasing comfort and raising body stiffness are issues of priority to the design engineer. The intelligent usage of many materials such as high strength steel, light-alloys and plastics enables a significant vehicle weight reduction to be achieved. The classical joining techniques used in the automobile industry need to be newly-evaluated since they often do not present workable solutions for such mixed-material connections, for example aluminium/steel. Calculation/simulation methods have made progress as a key factor for broader and more cost-effective implementation of structural bonding. This will lead to reduction of spotwelds and accelerate the car development. A special focus of the paper is the use of high strength steel grades. It will be shown that adhesive bonding is a key tool for yielding the potential of advanced high strength steel for low gauging without compromising the stiffness. The latest status of adhesive development has been described. Improvements with physical strength and glass temperature as well as of process relevant properties are shown. Also the situation regarding occupational hygiene is treated, showing that by further spotweld point reduction the emission around the working area can be even lowered against the current praxis. High performing lightweight design cannot longer do without high performing crash durable adhesives.

• Nuclear Engineering and Technology
• /
• v.47 no.7
• /
• pp.849-858
• /
• 2015

This study set the pyroprocess facility at an engineering scale as a cost object, and presented the cost consumed during the unit processes of the pyroprocess. For the cost calculation, the activity based costing (ABC) method was used instead of the engineering cost estimation method, which calculates the cost based on the conceptual design of the pyroprocess facility. The calculation results demonstrate that the pyroprocess facility's unit process cost is $194/kgHM for pretreatment, $298/kgHM for electrochemical reduction, $226/kgHM for electrorefining, and $299/kgHM for electrowinning. An analysis demonstrated that the share of each unit process cost among the total pyroprocess cost is as follows: 19% for pretreatment, 29% for electrochemical reduction, 22% for electrorefining, and 30% for electrowinning. The total unit cost of the pyroprocess was calculated at $1,017/kgHM. In the end, electrochemical reduction and the electrowinning process took up most of the cost, and the individual costs for these two processes was found to be similar. This is because significant raw material cost is required for the electrochemical reduction process, which uses platinum as an anode electrode. In addition, significant raw material costs are required, such as for $Li_3PO_4$, which is used a lot during the salt purification process.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.12
• /
• pp.105-113
• /
• 2008

In Ubiquitous Society, accurate Location Calculation of user's device is required to achieve the need of users. As the location calculation is processed by ranging between transceivers, if some obstacles exist between transceivers, NLoS(Non-line-of-Sight) components of received signal increase along with the reduction of LoS(Line-of-Sight) components. Therefore the location calculation error will increase due to the NLoS effect. The conventional location calculation algorithm has the original ranging error because there is no transformation of ranging information which degrades the ranging accuracy. The Iterative Calculation method which minimizes the location calculation error relys on accurately identifying NLoS or LoS condition of the tested channel. We employ Kurtosis, Mean Excess Delay and RMS Delay spread of the received signal to identify whether the tested channel is LoS or NLoS firstly. Thereafter, to minimize location calculation error, the proposed Iterative Calculation method iteratively select random range and finds the averaged target location which has high probability. The simulation results confirm the enhancement of the proposed method.

• Journal of the Korean Chemical Society
• /
• v.24 no.2
• /
• pp.91-100
• /
• 1980

A formula for calculation of the magnetic moments for octahedral $[Ti(III)A_3B_3]$ type complexes with axial symmetry has been developed and the magnetic moments for these complexes are calculated, using the experimental values of the distortion parameters$({\delta})$, spin-orbit coupling constants and orbital reduction factors. The calculated magnetic moments for axially distorted octahedral $[Ti(III)A_3B_3]$ type complexes are in resonable agreement with the experimental valuest It is found that the calculated magnetic moments decrease as the extent of axial distortion increases and the orbital reduction factor decreases. A calculation method of the magnetic moments for octahedral $[Ti(III)A_3B_3]$ type complexes which are in a ligand field of lower than axial symmetry has also been developed and the structure of distorted octahedral $[Ti(III)A_3B_3]$ type complexes are discussed on the basis of the of the calculated magnetic moments.