• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.2821-2829
• /
• 2011

Since the KTX was in operation in 2004, a number of researches on increasing the train speed have been conducted. Currently, the Honam High-speed train system is designed for the operation velocity of 350km/h. The societal demand expects higher operation speed, whereas the existing construction method and design specification are questioned in the KTX operation in the velocity over 350 km/h. In this study, a full-scale model test was conducted to obtain the preliminary data that is necessary to understand deformation characteristics of the reinforced road bed and the subgrade layers. In the full-scale model test, direct arrival seismic tests, crosshole seimic test, in-situ bender element test and sensing bar test were employed to measure the stiffness and deformation of the trackbed. The systematic analysis on the different set of measurements enhances the understanding of the behavior of the trackbed.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.501-506
• /
• 2004

This paper aims to suggest the feasibility of rapid operation scheme generated in preceding study, 'A study on development of operation planning for rapid service in urban railway(An introduction)' through application it to present subway lines in Seoul Metropolitan area. In case of line 3, without the Passing Track 'Turning train outstrip mode' is the best policy. In case of line 4, with the Passing Trank 'Passing track mode' may be the best way to realize the this scheme. Also, there is feasibility in the line 1, line 5, line 6, line 7 but there is no possibility it is applied to line 2 and line 8. In conclusion, this paper is intend to suggest the possibility of rapid operation in urban railway by presenting real operation scheme, time tables and amount of power usage and the number of composing trains and variety of demand,

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.9
• /
• pp.117-123
• /
• 1996

In this paper, we present a new learning method for the fuzzy ARTMAP which is effective for the noisy input patterns. Conventional fuzzy ARTMAP employs only fuzzy AND operation between input vector and weight vector in learning both top-down and bottom-up weight vectors. This fuzzy AND operation causes excessive update of the weight vector in the noisy input environment. As a result, the number of spurious categories are increased and the recognition ratio is reduced. To solve these problems, we propose a new method in updating the weight vectors: the top-down weight vectors of the fuzzy ART system are updated using weighted average of the input vector and the weight vector itself, and the bottom-up weight vectors are updated using fuzzy AND operation between the updated top-down weitht vector and bottom-up weight vector itself. The weighted average prevents the excessive update of the weight vectors and the fuzzy AND operation renders the learning fast and stble. Simulation results show that the proposed method reduces the generation of spurious categories and increases the recognition ratio in the noisy input environment.

• Proceedings of the KSPS conference
• /
• 1996.10a
• /
• pp.448-455
• /
• 1996

In this paper, we have proposed a VQ algorithm which uses a generating order to make quantize feature vector of speech signal. The proposed algorithm inspects what codeword follows a(ter present codeword and adds new index to established codebook, when mapping speech signal. We present a variable bit rate for new codebook, and propose an efficient compressed way of information. In this way, the number of computation and the number of codewords to be searched are reduced considerably. The performance of the proposed VQ algorithm is evaluated by spectrum distortion measure and bit rate. The obtained spectrum distortion is reduced about 0.22 [db], and the bit rate is saved over 0.21 bit/frame.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.68 no.4
• /
• pp.523-531
• /
• 2019

This paper deals with a wound-field synchronous machines(WFSM), with an electromagnet on its salient rotor, as an alternative to a permanent magnet in the rotor. We then examine the power performance characteristics, loss characteristics, V-curves and large short-circuit ratios for a large-scale synchronous generator, considering the leading and lagging operations, based on the finite-element method. We predict the performance of a 100MVA-class generator based on the operating range for a constant short-circuit ratio. At the last, We compared with the electromagnetic characteristics of three model according to number of slots.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.177-178
• /
• 2006

The enhancement of system security is one of the most important objectives of UPFC operation. To describe the system security, the index related to line flows and bus voltages are used. For the enhancement of security, the operation point of UPFC is set to minimize the index. This paper proposes the minimization algorithm using the Marquardt method. Moreover, the coefficients minimizing iteration number will be derived. For verification of the proposed operation scheme, numerical simulations have been performed on power system in Kwanju area, Korea with a UPFC.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.5
• /
• pp.153-160
• /
• 1998

A master-slave system for tele-operation had been developed and tested for several decades. In this paper the master robot is composed of several wires and provides position information of the handle which is driven by a operator within the master robot work space. A PC is used for the command calculation for a slave robot. This paper deals with the relation between the number of strings and D.O.F of the master robot, control method of the slave robot during the operation and the monitoring method over the working area by the computer graphics simulation. The D.O.F of the master robot can be modified by adding or subtracting some strings. The controller of the slave robot uses the advanced PD control method to keep the performance against varying working load.

• Journal of Communications and Networks
• /
• v.15 no.4
• /
• pp.398-406
• /
• 2013

In this paper, we investigate two types of in-phase and quadrature-phase (IQ) data transfer methods for cloud multiple-input multiple-output (MIMO) network operation. They are termed "after-precoding" and "before-precoding". We formulate a cloud massive MIMO operation problem that aims at selecting the best IQ data transfer method and transmission strategy (beamforming technique, the number of concurrently receiving users, the number of used antennas for transmission) to maximize the ergodic sum-rate under a limited capacity of the digital unit-radio unit link. Based on our proposed solution, the optimal numbers of users and antennas are simultaneously chosen. Numerical results confirm that the sum-rate gain is greater when adaptive "after/before-precoding" method is available than when only conventional "after-precoding" IQ-data transfer is available.

• The Journal of Information Technology
• /
• v.12 no.2
• /
• pp.39-47
• /
• 2009

Residue Number System is used for the purpose of increasing the speed of processing in the many application parts of Image Processing, Computer Graphic, Neural Computing, Digital Signal Processing etc, since it has the characteristic of parallelism and no carry propagation at each moduli. DRNS has the twice RNS Conversion, it is used to decreases the size of the operator in RNS. But it has a week point on the Second Residue to First Residue Conversion time. So, in this paper SRTFR(Second Residue to First Residue) Converter using MRC(Mixed Radix Conversion) is designed to decrease the size of RTB(Residue to Binary) Converter. Since the proposed SRTFR Converter using MRC(Mixed Rdix Convertion) has a pipeline processing. Also, modular operation is applied to at each partitioned SAM(Subtraction and Addition) and MA(Multiplication and addition). In the following study, the more effective design on MA is needed.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.1
• /
• pp.141-148
• /
• 2012

The power system of leisure ship has a character of stand-alone type, so it continuously checks the usable power. Especially, the leisure ship using renewable energy needs to adjust the power consumption of loads according to the usable power. Also, the important loads of leisure ship are different by operation mode. However, current power management system doesnot consider such character. This paper studied load management system of the SPMS(Smart Power Management System) and composed using the smart plug. The SPMS controls the loads depending on a user's pattern and character through variable priority number control. This control algorithm was verified through simulation of assumed user and situation using LabVIEW.