• Title/Summary/Keyword: frequency problem

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Study on Analysis of the Improvement and Problem for Automatic Fare Collection of Metropolitan Area Railway(Subway) (수도권 전철(지하철)의 역무자동화에 따른 문제점 분석 및 개선방안)

  • Lee, Tai-Sik;Moon, Deuk-Soo;Park, Eun-Soo;Lee, Jung-Ho
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1908-1912
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    • 2007
  • The metropolitan area needs to control the Automatic Fare Collection (AFC) and transportation card system in order to implement an efficient railway and subway. This paper introduces a suitable analysis to take advantage of the systematic method of the AFC and transportation card. These systems should consider the fare system, transportation pass and AFC equipment, which are organized with the Automatic Ticket Vending Machine, the Ticket Office Machine and the Card System of Radio Frequency (RF). However, the organization includes the fact the Automatic Ticket Vending Machine has a problem with the proceeding speed of passengers and inconvenience. Second, the majority of passengers have not utilized the Ticket Office Machine. Also, it should consider whether the transportation card is the proper system in the metropolitan area. Based on the analysis of national and international cases, it suggests that the AFC should make more improvements in the metropolitan area railway and subway.

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Low-Order Dynamic Output Feedback Controller Design Against Measurement Noise (측정 잡음을 고려한 저차의 동적출력궤환 제어기 설계)

  • Son, Young-Ik;Jo, Nam-Hoon;Shim, Hyung-Bo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.2
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    • pp.383-388
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    • 2007
  • This paper considers a low-order dynamic output feedback controller design problem. Since the proposed control law inherently has a low-pass filter property, it can alleviate the mal-effects of the sensor noise without additional filter designs. Frequency domain analysis shows the characteristics of the proposed control law against measurement noise. The effectiveness of the proposed control law is illustrated by numerical simulations with a rotary inverted pendulum and a convey-crane. Using only one integrator the proposed control law has the advantage to the stabilization problem with sensor noise as well as it can successfully replace the measurements of derivative terms in a state feedback control law.

Low Handover Latency for WiBro Network

  • Tae Ryoo-Kyoo;Park Se-Jun;Roh Jae-Hoon
    • 한국정보통신설비학회:학술대회논문집
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    • 2006.08a
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    • pp.43-46
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    • 2006
  • IEEE 802.16 WirelessMAN aiming to broadband wireless access (BWA) is evolving to 4G mobile communication system through the standardization of IEEE 802.16e supporting mobility on existing fixed WirelessMAN system. It is necessary for hand-over to provide seamless data service while MS (Mobile Station) moves to another BS (Base Station). Because the performance of handover affects packet loss or delay of any communications, it must consider low latency handover mechanism in packet based network. In this paper, we describes handover scheme of IEEE 802.16e with the cell edge interference problem and shows the way to solve the problem in frequency reuse one deployment. Our scheme reduces the handover latency and packet loss probability.

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Classification of PVC(Premature Ventricular Contraction) using Radial Basis Function network (Radial Basis Function 네트워크를 이용한 PVC 분류)

  • Lee, J.;Lee, K.J.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.439-442
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    • 1997
  • In our research, we will extract diagnostic parameters by LPC method and wavelet transform. Then, we will design artificial neural network which is based on RBF that can express input features in terms of fuzzy. Because PVC(Premature Ventricular Contraction) has possibility to cause heart attack, the detection of PVC is a very significant problem. To deal with this problem, LPC method which gives different coefficients or different morphologies and wavelet transform which has superior localization nature of time-frequency, are used to extract effective parameters or classification of normal and PVC. Because RBF network can allocate an input feature to the membership degree of each category, total system will be more flexible.

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A Study for Structural Damage Identification Method Using Genetic Algorithm (유전자 알고리즘을 이용한 구조물 손상 탐색기법에 관한 연구)

  • Woo, Ho-Kil;Choi, Byoung-Min
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.1 s.118
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    • pp.80-87
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    • 2007
  • In this paper, a method for identifying the location and extent of a damage in a structure using residual forces was presented. Element stiffness matrix reduction parameters in a finite element model were used to describe the damaged structure mathematically. The element stiffness matrix reduction parameters were determined by minimizing a global error derived from dynamic residual vectors, which were obtained by introducing a simulated experimental data into the eigenvalue problem. Genetic algorithm was used to get the solution set of element stiffness reduction parameters. The proposed scheme was verified using Euler-Bernoulli beam. The results were presented in the form of tables and charts.

New Material for a Super Resolution Disc

  • Kwak, Keum-Cheol;Kim, Sun-Hee;Lee, Chang-Ho;Song, Ki-Chang
    • Transactions of the Society of Information Storage Systems
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    • v.3 no.2
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    • pp.54-58
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    • 2007
  • Using metal/Si materials as a recording layer, we have achieved good results for a SR disc (super resolution disc). Mainly by controlling metal composition and the ratio of metal to Si of recording layer, signal qualities were greatly enhanced. At the mark length of 75nm, the best CNR (Carrier to Noise Ratio) was about 45dB. Write power was reduced down to about 6.5mW. LFN (Low Frequency Noise) could also be reduced down to 14dB. Single tone pattern jitters for every mark whose length is from 2T through 8T were achieved to be below 10%. The readout signal was stable sustaining CNR>40dB during about 15,000 times reading. The so-called "3T-problem" could be avoided.

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Optimal Evasive Maneuver for Sea Skimming Missiles against Close-In Weapon System (근접방어무기체계에 대한 함대함 유도탄의 최적회피기동)

  • Whang, Ick-Ho
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2096-2098
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    • 2002
  • In this paper, the optimal evasive maneuver strategies for typical subsonic ASM(anti-ship missile) to reach its target ship with high survivability against CIWS(close in weapon system) are studied. The optimal evasive maneuver input is defined by the homing command optimizing the cost function which takes aiming errors of CIWS into account. The optimization problem for the effective evasive maneuver is formulated based on a simple missile dynamics model and a CIWS model. By means of solving the problem, a multiple hypotheses testing method is proposed. Since this method requires generation of too many hypotheses, the hypothesis-pruning technique is adopted. The solution shows that the optimal evasive maneuver is a bang-bane shaped command whose frequency is varied by the aimpoint determination strategy in CIWS.

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A Study on Medications and Health Histories of 2,528 Dental Patients (초진시 치과환자가 복용중인 약과 병력에 관한 조사연구)

  • 고경용;정성창
    • Journal of Oral Medicine and Pain
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    • v.5 no.1
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    • pp.17-25
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    • 1980
  • The purpose of this survey is to determine what medication dental patients are taking and to compile information from medical histories on the most frequent conditions. The frequency of use of drug and positive medical findings are reported by age and sex group. 1.Use of drugs were found to increase with age. The proportion taking a medication was 1 in 5 for teenage group, 1 in 4 for young adults, 1 in 3 for patients in their 40s, and 1 in 2 for patients aged 50and older. 2. One seconds of all dental patients in the study had a positive medical history for at least one problem, and more than 35% of these patients reported multiple medical problem.

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Optimal sequencing of 1D acoustic system for sound transmission loss maximization using topology optimization method (전달손실 최대화를 위한 위상최적화기반 1차원 흡차음시스템의 최적 배열 설계)

  • Kim, Eun-Il;Lee, Joong-Seok;Kim, Yoon-Young;Kim, Jung-Soo;Kang, Yeon-June
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.309-314
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    • 2007
  • Optimal layer sequencing of a multi-layered acoustical foam is solved to maximize its sound transmission loss. A foam consisting of air and poroelastic layers can be optimized when a limited amount of a poroelastic material is allowed. By formulating the sound transmission loss maximization problem as a one dimensional topology optimization problem, optimal layer sequencing and thickness were systematically found for several frequencies. For optimization, the transmission losses of air and poroelastic layers were calculated by the transfer matrix derived from Biot's theory. By interpolating five intrinsic parameters among several poroelastic material parameters, dear air-poroelastic layer distributions were obtained; no filtering or post-processing was necessary. The optimized foam layouts by the proposed method were shown to differ depending on the frequency of interest.

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Scattering characteristic analysis of Fresnel zone plate lens using TLM (TLM법을 이용한 프레넬 존 플레이트 렌즈 산란특성 해석)

  • 김태용
    • Proceedings of the Korea Society for Simulation Conference
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    • 2003.06a
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    • pp.15-18
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    • 2003
  • Most numerical techniques such as FEM, BEM, and MOM are able to analize electromagnetic scattering problems from arbitrary shapes. Although these methods could be applied to compute electromagnetic scattering problems in frequency domain, it was limited for electrodynamic problem in time domain. In this paper, electromagnetic scattering problem from Fresnel zone plate lens are considered. Some numerical results computed by TLM are compared with Kirchhoff's approximation and PO method.

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