• Title/Summary/Keyword: 로렌츠

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Development a Tool Which Can be Used in Factor Analysis of Inequality on Mathematics Scholastic Achievement (수학 학업성취의 불평등을 측정할 수 있는 도구의 개발)

  • Lee, Kang-Sup;Park, Yong-Beom
    • Communications of Mathematical Education
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    • v.21 no.2 s.30
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    • pp.321-330
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    • 2007
  • The purpose of this study is to develop a tool which can be used in factor analysis of inequality on mathematics education. The objectives for study are develop an index that can be used to find a deviation of objects on mathematics scholastic achievement. The results of this study are deviation index of objects on mathematics scholastic achievement which development can be applications to Gini coefficient.

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Chaotic dynamics of the multiplier based Lorenz circuit (곱셈기 기반 로렌츠 회로의 카오스 다이내믹스)

  • Ji, Sung-hyun;Song, Han-Jung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.26 no.4
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    • pp.273-278
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    • 2016
  • In this paper, chaotic circuit of the Lorentz system using multipliers, operational amplifiers, capacitor, fixed resistor and variable resistor for control has been designed in a electronic circuit. Through PSPICE program, electrical characteristics such as time waveforms, frequency spectra and phase attractors analyzed. And in the special area ($10{\sim}100k{\Omega}$) of the $500k{\Omega}$ control variable resistor, the circuit showed chaotic dynamics. Also, we implemented the circuit in a electronic hardware system with discrete elements. Measured results of the circuit coincided with simulated data.

Improvement of arc quenching room in Molded Case Circuit Breaker using Finite Elements Methode (유한요소법을 이용한 Molded Case Circuit Breaker소호부의 소호능력 향상)

  • Kim, Yu-Min;Cho, Sung-Hoon;Kwon, Jung-Hun;Lim, Kee-Joe
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1550-1551
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    • 2011
  • 본 논문은 가정에서 사용하는 중 저압용 차단기의 차단 능력을 향상시키기 위한 방법에 초점을 두었다. MCCB의 차단 능력은 MCCB내부 부품들의 재료나 형상 그리고 배열 등 여러 요소에의해 결정된다. 특히 본 논문에서는 MCCB 그리드의 형상을 변화하여 소호시간을 단축하는 방법을 제안하였다. 사고에 의해 차단기가 작동하게 되면 차단기 내부 접점에서 Arc가 발생하게 된다. 이때 발생된 Arc에의한 2차 사고를 방지하기위해, Arc를 빠른 시간에 소호시켜야한다. Arc가 발생하게 되면 Arc내부는 도체처럼 전류가 흐르게 되는데 이 전류에 의해 소호부의 그리드를 따라 자속이 형성된다. 그리드의 형상에 따라 Arc 기둥 주변에 불균형적인 자속이 유도되고 이 불균형한 자속에 의해 Arc 주변에는 불균형한 로렌츠힘이 발생하여 일정 방향으로 힘이 작용하게 된다. 이때 발생한 로렌츠힘 에의해 Arc 기둥은 그리드 방향으로 소호된다. 분석을 위해 유한요소법을 이용한 시뮬레이션을 사용하였고 그리드 형상 변화를 통해 일정방향으로 로렌츠힘이 변화 전보다 증가한 결과를 얻었다. 본 논문의 내용에 추가로 그리드 내부에서 자속의 이동을 효율적으로 전달하기위한 방법을 연구하면 더 큰 로렌츠힘을 얻어 소호시간을 단축시킬 수 있을 것으로 사료된다.

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Goodness-of-fit test for the gumbel distribution based on the generalized Lorenz curve (일반화된 로렌츠 곡선을 기반으로 한 Gumbel 분포의 적합도 검정)

  • Lee, Kyeongjun
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.4
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    • pp.733-742
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    • 2017
  • There are many areas of applications where Gumbel distribution are employed such as environmental sciences, system reliability and hydrology. The goodness-of-fit test for Gumbel distribution is very important in environmental sciences, system reliability and hydrology data analysis. Therefore, we propose the two test statistics to test goodness-of-fit for the Gumbel distribution based on the generalized Lorenz curve. We compare the new test statistic with the Anderson - Darling test, Cramer - vonMises test, and modified Anderson - Darling test in terms of the power of the test through by Monte Carlo method. As a result, the new test statistics are more powerful than the other test statistics. Also, we propose new graphic method to goodness-of-fit test for the Gumbel distribution based on the generalized Lorenz curve.

A study on synchronization of lorenz-based dicrete chaotic with application to communcation encryption (통신암호화에 응용된 로렌츠 기반 이산 카오스의 동기화에 관한 연구)

  • Park, Chul;Kim, Young-Tae;Ko, Hyung-Hwa
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.11
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    • pp.2488-2497
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    • 1997
  • In this paper, a computer simulation of the Lornz discrete chaotic system is described. The chotic behavior closely matches the results predicted by numerical simulations. Using the concept of discrete synchronized chaotic systems, the possibility of a secure communication is proved by simulating the Lorenz system in both the transmitter and receiver. In the proposed approach, at first, a chaotic modulating signal is multiplied with the message, and these are transmitted with adding a chaotic modulating signals, and then at the receiver, the chaotic modulating signal is regenerated and divided from the receiver signal. Varying a smapling time interval to calibrate the robustness of the Lorenz discrete synchronized chaotic system as a nonlinear state estimator, we measured the performance of the Lorenz discrete syncrhonized chaotic system by comparing the synchronization error and the error between transmitted signal and received signal.

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Measuring Hadoop Optimality by Lorenz Curve (로렌츠 커브를 이용한 하둡 플랫폼의 최적화 지수)

  • Kim, Woo-Cheol;Baek, Changryong
    • The Korean Journal of Applied Statistics
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    • v.27 no.2
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    • pp.249-261
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    • 2014
  • Ever increasing "Big data" can only be effectively processed by parallel computing. Parallel computing refers to a high performance computational method that achieves effectiveness by dividing a big query into smaller subtasks and aggregating results from subtasks to provide an output. However, it is well-known that parallel computing does not achieve scalability which means that performance is improved linearly by adding more computers because it requires a very careful assignment of tasks to each node and collecting results in a timely manner. Hadoop is one of the most successful platforms to attain scalability. In this paper, we propose a measurement for Hadoop optimization by utilizing a Lorenz curve which is a proxy for the inequality of hardware resources. Our proposed index takes into account the intrinsic overhead of Hadoop systems such as CPU, disk I/O and network. Therefore, it also indicates that a given Hadoop can be improved explicitly and in what capacity. Our proposed method is illustrated with experimental data and substantiated by Monte Carlo simulations.

PSPICE analysis of the Lorenz circuit using the MOS resistor (MOS 가변저항을 이용한 로렌츠 회로의 PSPICE 해석)

  • Ji, Sung-Hyun;Kim, Boo-Kang;Nam, Sang-Guk;Nguyen, Van Ha;Park, Yong Su;Song, Han Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.2
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    • pp.1348-1354
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    • 2015
  • In this paper, chaotic circuit of the voltage controlled Lorentz system for engineering applications has been designed and implemented in an electronic circuit. The proposed circuit consists of MOS variable resistor, multipliers, capacitors, fixed resistors and operational amplifiers. The circuit was analysed by PSPICE program. PSPICE simulation results show that chaotic dynamics of the circuit can be controlled by the MOS variable resistor through time series analysis, frequency analysis and phase diagrams. Also, we implemented the proposed circuit in an electronic hardware system with discrete elements. Measured results of the circuit showed controllability of the circuit using the MOS resistor.

Microcontroller based Chaotic Lorenz System for Secure Communication Applications (암호통신 응용을 위한 마이크로 컨트롤러 기반 로렌츠 카오스 시스템)

  • Jayawickrama, Chamindra;Song, Hanjung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.12
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    • pp.1698-1704
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    • 2018
  • This paper presents a implementation of a chaotic Lorenz system for data secure communication applications. Here we have used PIC18F family-based microcontroller to generate the chaotic signal, and simulated waveform patterns confirm that the chaotic behavior of the microcontroller based discrete time chaotic Lorenz system. There are three R-2R ladder type A/D converters have been implemented for conversion of direct microcontroller digital output into analog waveform, utilizing this specific microcontroller relevant to this experiment work, microcontroller ports B, C and D have been utilized for its time waveform outputs X, Y and Z respectively. XC8 compiler used for the compilation of the program. MATLAB and PROTEUS software platforms are used for simulation. Finally, chaotic time wave forms, 2D chaotic attractors were obtained and secure communication analog waveforms were also verified by experimental measurement.

Goodness of Fit Tests for the Exponential Distribution based on Multiply Progressive Censored Data (다중 점진적 중도절단에서 지수분포의 적합도 검정)

  • Yun, Hyejeong;Lee, Kyeongjun
    • Journal of the Korean Data Analysis Society
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    • v.20 no.6
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    • pp.2813-2827
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    • 2018
  • Progressive censoring schemes have become quite popular in reliability study. Under progressive censored data, however, some units can be failed between two points of observation with exact times of failure of these units unobserved. For example, loss may arise in life-testing experiments when the failure times of some units were not observed due to mechanical or experimental difficulties. Therefore, multiply progressive censoring scheme was introduced. So, we derives a maximum likelihood estimator of the parameter of exponential distribution. And we introduced the goodness-of-fit test statistics using order statistic and Lorenz curve. We carried out Monte Carlo simulation to compare the proposed test statistics. In addition, real data set have been analysed. In Weibull and chi-squared distributions, the test statistics using Lorenz curve are more powerful than test statistics using order statistics.

The Enhancement of Antenna Near-Field Measurements Using Near-Field to Far-Field Transform Algorithms Based on the Lorentz Reciprocity Theorem (로렌츠 상호작용 원리와 근역장-원역장 변환 공식을 이용한 안테나 근역장 측정 알고리즘 개선)

  • Cho, Yong-Heui
    • The Journal of the Korea Contents Association
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    • v.6 no.2
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    • pp.51-58
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    • 2006
  • The enhancement of antenna near-field measurements is obtained using a general probe compensation equation based on the Lorentz reciprocity theorem and reciprocity notation. The probe compensation is an essential process of the near-field to far-field transformations. Applying the equation proposed in this paper to a planar scanning for a rectangular horn antenna shows that our near-field radiation pattern is similar to that of a far-field and our theory is very simple to use and suitable for most practical applications.

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