• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.924-931
• /
• 2011

This paper deal with maximum span calculation technique for 350km/h high speed catenary system. Considers a geometric interaction, possible maximum span length is between two pole. Wind condition and the train current collector is moving even to being pantograph does not escape while operating. Uses like this justice and possible maximum span length is follow next condition. (i) Operating range of pantograph fan head, (ii) The wind velocity which assumes from system, (iii) Width in pantograph from operation height moving, (iv) Type of processing Catenary system, specially tensile strength of overhead contact wire and messenger wire etc. When accurately calculates the maximum permission span, the dropper between of overhead contact wire and messenger wire and must consider the correlation.

• 전기전자학회논문지
• /
• 제18권3호
• /
• pp.403-408
• /
• 2014

본 논문은 Varying Interpolator를 개선하여 다수의 Pixel을 한 번에 처리할 수 있는 Rasterizer 구조를 제안한다. 설계한 Rasterizer의 Varying Interpolator는 한 번에 16 Pixel을 처리 할 수 있으며 최대 64개의 색상을 출력으로 가진다. 또한 Rasterizer의 연산을 행렬연산 및 행렬변환으로 구성하여 연산의 중복성을 줄이고 재사용성을 높여 Rasterizer의 처리 속도를 높였다. 제안하는 구조의 Rasterizer 는 기존의 연구와 비교하여 색상 보간은 11%, Rasterizer 전체 처리 속도는 17% 향상된 성능을 보였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1994년도 하계학술대회 논문집 A
• /
• pp.482-484
• /
• 1994

In this paper, to realize high speed position control of LDM (Linear DC Motor), the minimum time control method is applied. But, In this control method, calculation of non-linear function is required Therefore, in order to avoid this complex calculation, optimum switching of the Bang-Bang control is done on parabola type switching function established in the plane of phase. But, the sliding mode is occurred due to the modeling error of LDM and the variation of parameters. Thereby, the optimum 'control is not realized. In order to realize optimum control, the algorithm to modify switching function is proposed

• 한국소음진동공학회논문집
• /
• 제24권6호
• /
• pp.452-461
• /
• 2014

Two stroke low speed diesel engines that have many advantages such as high thermal efficiency and durability have been widely used for marine engine. However, it is also true that many problems have occurred due to the high explosion pressure and severe operating environment. Especially problems of shaft damage etc. intensively occurred due to the phenomenon of crankshaft exceeding the allowable stress, including the shaft vibration of the engine model in the early stage. In this study, the crankshaft fracture phenomenon of early engine model was evaluated and analyzed by using up-to-date torsional vibration calculation program and measurement instrument. And this was numerically shown.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 추계학술대회 논문집
• /
• pp.328-333
• /
• 2004

With the introduction of KTX, in my view it is necessary to secure the reliability of high-speed trains, make them stabilized at the earliest moment possible, and completely digest them as our own system for the purpose of being second to none in the area of railroad business. I am going to study in this thesis through analysis of train failures by help of MKBSF calculation, breaking from the convention in maintaining the high-speed trains, in order to establish and apply the computerized system called as RCM (Reliability Centered Maintenance), foster manpower in charge of the reliability maintenance, and realize the scientific and efficient maintenance covering the whole field of maintenance. Depending on how efficiently and scientifically we can perform the maintenance activities, we will be able to not only reduce the maintenance cost but also ensure the railroad security, and as a natural consequence improve the railroad image much better.

• Journal of information and communication convergence engineering
• /
• 제11권4호
• /
• pp.282-287
• /
• 2013

A real-time digital holographic display is the core technology for the next-generation 3DTV. Holographic display requires a considerably large amount of calculation. If generating a large number of digital holograms is intended, the amount of calculation and the time required increase exponentially. This is a significant obstacle in a real-time hologram service. This paper proposes an algorithm that increases the speed of generating a Fresnel hologram by using a recursive addition operation covering the entire coordinate array of a digital hologram. The 3D object designed to calculate the digital hologram uses a depth-map image produced by computer graphics. The proposed algorithm is a technique that performs the computer-generated holography (CGH) operation with only recursive addition of all of the hologram's coordinates by analyzing the regularity between the 3D object and the digital hologram coordinates. The experimental results show that the proposed algorithm increases the operation speed by 70% over the technique using the conventional CGH equation and by more than 30% over the previously proposed recursive technique.

• 전자공학회논문지B
• /
• 제28B권9호
• /
• pp.712-718
• /
• 1991

In this paper, we propose a graphic system for high speed generation of bitmap font data from the outline font data such as PostScript, etc. In desk-top publishing system. A VLSI chip called KAFOG was designed for the high-speed calculation of a cubic Bezier curve, which was implemented in 1.5\ulcorner CMOS gate array using 17,000 gates. A cubic Bezier curve is approximated by a set of line segments in KAFOG at the throughput of 250K curves per second with the clock frequency of 40 MHz. A prototype graphic system was developed using two MC6800 microprocessors and the KAFOG chip. Two microprocessors cooperate in a master and slave mode, and handshaking is used for communication between two processors. KAFOG chip, being controlled by the slave processor, operates as a coprocessor for the calculation of the outline font. The throughput of the prototype graphic system is 40 64$\times$64 outline fonts per sencond.

• Journal of Mechanical Science and Technology
• /
• 제20권8호
• /
• pp.1240-1247
• /
• 2006

Large eddy simulation of turbulent premixed flame in turbulent channel flow is studied by using G-equation. A flamelet model for the premixed flame is combined with a dynamic subgrid combustion model for the filtered propagation flame speed. The objective of this work is to investigate the validity of the dynamic subgrid G-equation model to a complex turbulent premixed flame. The effect of model parameters of the dynamic sub grid G-equation on the turbulent flame speed is investigated. In order to consider quenching of laminar flames on the wall, wall-quenching damping function is employed in this calculation. In the present study, a constant density turbulent channel flow is used. The calculation results are evaluated by comparing with the DNS results of Bruneaux et al.

• Steel and Composite Structures
• /
• 제13권6호
• /
• pp.561-570
• /
• 2012

Seismic collapse analysis requires efficient and automated method to perform thousands of time history analyses. The paper introduced the advantages of speed and convergence property of explicit method, provided a few techniques to accelerate speed of calculation and developed an automated procedure for collapse assessment, which combines the strong capacity of commercial explicit finite element software and the flexible, intelligent specialties of control program written in FORTRAN language aiming at collapse analysis, so that tedious and heavy work of collapse analysis based on FEMAP695 can be easily implemented and resource of calculation can be made the best use of. All the key commands of control program are provided to help analyzers and engineers to cope with collapse assessment conveniently.

• 한국항공운항학회지
• /
• 제31권4호
• /
• pp.7-18
• /
• 2023

The continuous increase in air traffic emphasizes the importance of capacity calculation. Research on the calculation method of Terminal Control Area (TMA) capacity has been treated as a partial aspect of the airspace sector capacity or has been limitedly studied. This study aims to propose a mathematical model for calculating TMA capacity, taking into account the Standard Terminal Arrival Route (STAR), separation standards, TMA entry speed, and runway threshold passing speed. The proposed model has the advantage of being able to calculate the instantaneous arrival capacity, which has not been noted in previous studies, along with the throughput. Additionally, it is meaningful as the model can easily calculate the arrival capacity of the TMA considering airport construction, runway expansion, or new procedures.