• Title/Summary/Keyword: level of error

Search Result 2,493, Processing Time 0.033 seconds

The Effects of Noise, Interference, and Carrier Offset on Multi-Level QPRS Signals (다치 직교 PRS 신호에 대한 잡음과 간섭 및 캐리어 옵셋의 영향)

  • Lee, Gwang-Ryel;Cho, Sung-Joon
    • Proceedings of the KIEE Conference
    • /
    • 1987.07b
    • /
    • pp.869-873
    • /
    • 1987
  • In this study, we have examined the multi-level QPRS system in point of error rate, which requires narrow bandwidth and has Little ISI. The generalized error rate equations of multi-level QPRS signal have been derived in the presence of Gaussian noise and co-channel CW interference. And the error rate performance of 9, 49, 225 QPRS system is investigated as parameters of carrier power-to-noise power, carrier power-to -interference power. Also, we have investigated the effect of carrier offset.

  • PDF

Real time Image Processor for Reproduction of Gray Levels in Dark Areas on Plasma Display Panel (PDP) (플라즈마 디스플레이 패널의 어두운 영역에서의 계조 재현을 위한 실시간 영상처리기)

  • Lee, Chang-Hun;Park, Seung-Ho;Gang, Jin-Gu;Kim, Chun-U
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.51 no.1
    • /
    • pp.46-54
    • /
    • 2002
  • Plasma Display Panel (PDP) is required to be both the determination of white point of each gray level and the inverse gamma correction since no-balanced RGB cell and linear property of PDP, respectively. However, these two methods cause degradation of grey level representation and undesirable false contour in the dark areas on PDP. In this paper, we implemented real time image processor of the proposed error diffusion algorithm and unsharp masking operation to protect the blurring image caused by the error diffusion. Experimental results showed drastic improvements of gray level representation and reduction of undesirable false contour.

Inviscid Rotational Flows Near a Corner and Within a Triangle

  • Suh, Yong-Kweon
    • Journal of Mechanical Science and Technology
    • /
    • v.15 no.6
    • /
    • pp.813-820
    • /
    • 2001
  • Solutions of inviscid rotational flows near the corners of an arbitrary angle and within a triangle of arbitrary shapes are presented. The corner-flow solutions has a rotational component as a particular solution. The addition of irrotatoinal components yields a general solution, which is indeterminate unless the far-field condition is imposed. When the corner angle is less than 90$^{\circ}$the flow asymptotically becomes rotational. For the corner angle larger than 90$^{\circ}$it tends to become irrotational. The general solution for the corner flow is then applied to rotational flows within a triangle (Method I). The error level depends on the geometry, and a parameter space is presented by which we can estimate the error level of solutions. On the other hand, Method II employing three separate coordinate systems is developed. The error level given by Method II is moderate but less dependent on the geometry.

  • PDF

A 9-Rule Fuzzy Logic Controller of the Nuclear Steam Generator (핵증기 발생기의 9룰 퍼지논리 제어기)

  • Lee, Jae-Young;No, Hee-Cheon
    • Nuclear Engineering and Technology
    • /
    • v.25 no.3
    • /
    • pp.371-380
    • /
    • 1993
  • A model free controller utilizing a set of linguistic fuzzy logic of the human operator's experience is developed to control the steam generator water level in a pressurized water reactor. Only 9 rules for control action are generated from the inputs of water level error and mass flow error implicitly representing the time variation of the collapsed water level. The bell type membership functions of the premise side and the result side are tuned by the sensitivity study. This compact fuzzy logic controller shows a robust control during transient and no offset error and oscillation during steady state operation. For a multi-ramp power increase from start-up to full power, the proposed controller shows good performance for the entire range.

  • PDF

EFFECT OF IMPRESS10N TECHNIQUE ON THE ACCURACY OF MASTER CAST FOR IMPLANT PROSTHESIS (인상채득법이 임플랜트 주모형의 정확성에 미치는 영향)

  • Kim Young-Oh;Yang Hong-So;Vang Mong-Sook;Park Sang-Won;Park Ha-Ok;Lee Jai-Bong
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.44 no.1
    • /
    • pp.63-72
    • /
    • 2006
  • Purpose: The purpose of this study was to compare the accuracy of master cast fabricated by using different impression methods at the different impression levels. Material and Method: The master model used in this study was resin block having low implant analogs. Impression method studied were 1) direct method on future level (Group FIX-D), 2) Indirect method on fixture level(Group FIX-I), 3) Modified indirect method on fixture level(Group FD(-M), 4) Direct method on abutment level(Group AB-D) and 5) Indirect method on abutment level(Group AB-I). Each of the five groups took 10 impressions. Fifty impressions were made for master cast by using Impregum $F^(R)$ impression material loaded on individual tray. Three dimensional measuring microscope was used to measure the inter-implant distance. Error rate of each inter-implant distance were calculated and evaluated. Results: The results were as follows. 1. Group FIX exhibited higher accuracy than group AB. 2 In group FIX, modified indirect method showed the highest accuracy, while indirect method showed the lowest accuracy. In group Ab, indirect method showed the higher accuracy than direct method. 3. Group FIX showed larger horizontal error than group AB. But, group AB showed the larger vertical error than group FIX. 4. Group Fix-M showed smallest vertical and horizontal error.

An Improved Current Control Method for Three-Phase PWM Inverters Using Three-Level Comparator (3레벨 비교기를 이용한 3상인버터의 개선된 히스테리시스 전류제어 기법)

  • Moon, Hyoung-Soo;Han, Woo-Yong;Lee, Chang-Goo;Sin, Dong-Yong;Kim, Mu-Youn
    • Proceedings of the KIEE Conference
    • /
    • 2001.07b
    • /
    • pp.1035-1037
    • /
    • 2001
  • This paper presents an improved hys- teresis current control method for three-phase PWM power inverters using 3-level comparator. Hysteresis current controller using 3-level comparator has an advantage of constant switching frequency compared with conventional hysteresis current controller. However, this method has disadvantage that the longer sampling period, the larger current error because the switching is performed without considering current error magnitude of each phase. The proposed method improves the control performance by selecting the optimum switching pattern in which the magnitudes of current errors are considered introducing space vector concept. Simulation results using Matlab/Simulink show that the proposed control method reduces current error keeping the merit of previous hysteresis current control method.

  • PDF

Improving Reliability of the Last Level Cache with Low Energy and Low Area Overhead (낮은 에너지 소모와 공간 오버헤드의 Last Level Cache 신뢰성 향상 기법)

  • Kim, Young-Ung
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.12 no.2
    • /
    • pp.35-41
    • /
    • 2012
  • Due to the technology scaling, more transistors can be placed on a cache memories of a processor. However, processors become more vulnerable to the soft error because of the highly integrated transistors, and consequently, the reliability of the cache memory must consider seriously at the design space level. In this paper, we propose the reliability improving technique which can be achieved with low energy and low area overheads. The simulation experiments of the proposed scheme shows over 95.4% of protection rate against the soft error with only 0.26% of performance degradations. Also, It requires only 2.96% of extra energy consumption.

Hierarchical Feedback Control of Large-Scale Discrete-Time Systems with Coupled States and Inputs (상태 및 입력이 결합된 대규모 이산시간 시스템의 계층적 궤환제어)

  • 김경연;전기준
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.39 no.5
    • /
    • pp.470-477
    • /
    • 1990
  • Singh's multi-level method is extended to the optimal tracking control of a large interconnected dynamical system which has coupled states and coupled inputs. The steady-state tracking error and a convergence condition for the extended multi-level method are derived analytically and the results show that the steady-state tracking error and a convergence rate have to be compromised. Also, a new multi-level method which is advantageous over the Singh's method in steady-state tracking error and computational burden is proposed by introducing nominal inputs into the performance index. The resulting feedback gain matrix and the compensation vector are optimal for all initial conditions so that eventual on-line computation is minimal.

  • PDF

Blind Adaptation Algorithms Using Coarse Error Estimation and Fine Error Estimation (거친 오차 추정과 미세 오차 추정을 활용한 블라인드 적응 알고리즘)

  • Oh, Kil-Nam
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.13 no.8
    • /
    • pp.3660-3665
    • /
    • 2012
  • For blind equalization, it is necessary to open an eye pattern quickly in the early stage of equalization, after that it is important to lower an error level of equalizer output signal. This paper discusses coarse error estimation using signal points specifically determined and fine error estimation using original signal constellation, and proposes two suggestions for how to take advantage of the two error estimation methods. The two error estimates, respectively, are effective to quickly open an eye pattern in the state of eye pattern closed, or to lower the level of an error in the steady-state after the eye pattern opening. Two blind equalization algorithms are proposed and their performances are compared, which select one of the two error estimates depending on the state of convergence of the equalizer, or combine two errors weightedly according to the relative reliabilities of the two error estimates, and calculate the new error.

Contextual-Bandit Based Log Level Setting for Video Wall Controller (Contextual Bandit에 기반한 비디오 월 컨트롤러의 로그레벨)

  • Kim, Sung-jin
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2022.05a
    • /
    • pp.633-635
    • /
    • 2022
  • If an error occurs during operation of the video wall controller, the control system creates a log file and records the log. In order to minimize the load on the system due to log recording, the log level is set so that the log is not recorded as much as possible under normal operating conditions. When an error occurs, detailed logs are recorded by changing the log level to analyze and respond to the cause of the error. So work efficiency is reduced, and operator intervention is inevitable to change the log level. In this paper, we propose a model that automatically sets the log level according to the operating situation using Contextual Bandit.

  • PDF