• Title/Summary/Keyword: invariance

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ESPRIT target position estimation with uniform linear array and uniform circular array (등간격 선형어레이와 등간격 원형어레이 레이더를 위한 ESPRIT 표적 위치 추정 기법)

  • NamGoong, Geol;Lim, Jong-Tae;Yoo, Do-Sik
    • Journal of Advanced Navigation Technology
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    • v.16 no.6
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    • pp.952-959
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    • 2012
  • In this paper, we propose an ESPRIT based algorithm for target position estimation with uniform linear array (ULA) and uniform circular array (UCA) at transmitter and receiver, respectively. When UCA is adopted at the receiver, unlike the case of ULA at the receiver, the rotational invariance of the received signal is satisfied. Although there has been an attempt to resolve this issue, the problem of direction of departure estimation has not been considered. In this paper, we provide an ESPRIT based algorithm to simultaneously estimate transmitter elevation angle, receiver elevation angle, and receiver azimuth angle, taking into account the transmitter antennas as well as the receiver antennas.

A study on Translation-, Magnification- and Rotation- Invariant automatic Inspection System Development (이동, 배율, 회전에 무관한 자동 검사 장치 개발에 관한 연구)

  • O, Chun-Seok;Im, Jong-Seol
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.4
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    • pp.1136-1142
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    • 1999
  • A difficulty of the visual inspection for translated, magnified and rotated objects exists owing to the limitation of recognition rate. In this paper, we perform to define Integral Logarithm Transform(ILT), to consider its characteristic for implementation of Translation-, Magnification- and Rotation-invariant inspection system, and to compare with other methods in inspection error rate. By using magnification and rotation invariance properties of ILT, it makes easier than other methods to extract the rotation degree. The new method employs the ILT for the good/bad inspection of translated, magnified and rotated objects and experiment is performed to achieve translation, magnification and rotation invariance. In other methods both magnification and rotation invariance can't be available. As the result of he experiment, it is not better than the self-organizing map in the improvement of recognition rate, but it shows us the possibility to be used as a tool for the good/bad inspection system.

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Causal reasoning studies with a focus on the Power Probabilistic Contrast Theory (힘 확률 대비 이론에 기반을 둔 인과 추론 연구)

  • Park, Jooyong
    • Korean Journal of Cognitive Science
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    • v.27 no.4
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    • pp.541-572
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    • 2016
  • Causal reasoning is actively studied not only by psychologists but, in recent years, also by cognitive scientists taking the Bayesian approach. This paper seeks to provide an overview of the recent trends in causal reasoning research with a focus on the power probabilistic contrast theory of causality, a major psychological theory on causal inference. The power probabilistic contrast theory (PPCT) assumes that a cause is a power that initiates or inhibits the result. This power is purported be understood through statistical correlation under certain conditions. The paper examines the supporting empirical evidence in the development of PPCT. Also, introduced are the theoretical dispute between the PPCT and the model based on Bayesian approach, and the current developments and implications of research on causal invariance hypothesis, which states that cause operates identically regardless of the context. Recent studies have produced experimental results that cannot be readily explained by existing empirical approach. Therefore, these results call for serious examination of the power theory of causality by researchers in neighboring fields such as philosophy, statistics, and artificial intelligence.

Lift-Off Invariance Transformations for Electromagnetic Eddy Current Nondestructive Evaluation Signals (다양한 센서 측정 거리로부터 획득한 자기적 와전류 신호의 불변 변환 처리 기법)

  • Kim, Dae-Won
    • Journal of the Korean Magnetics Society
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    • v.14 no.6
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    • pp.207-212
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    • 2004
  • Eddy current (EC) testing methods are widely used in a variety of applications including the inspection of steam generator tubes in nuclear power plants, aircraft parts and airframes. A key factor that affects the EC signal is lift-off which means the physical distance between a sensor and a specimen in the testing. In practice, it is difficult to keep track of the actual value of the lift -off during a specific experiment, simulation or testing in the field, which is essential for accurate interpretation of the signal to be used in the following steps. Hence it is necessary to have a scheme to render the EC signal invariant to the effects of lift-off in spite of the changes in the real world. This paper describes a new method for compensating EC signals for variations in lift-off by acquiring an invariance feature using a homomorphic operator and neural network techniques. The signals from various lift-offs are transformed to obtain a zero lift-off equivalent signal that can be subsequently used for defect characterization in the next step.

The Difference of Invariance, Reliability of The Student Engagement Scale (ESE) In Distance-Learning During Covid-19 Pandemic in Light of Some Students' Characteristics

  • Almaleki, Deyab A.;Alzahrani, Abdulrahman J.;Alkhairi, Mohammed A.;Albalawi, Farhan A.;Albogami, Hosin A.;Alhajory, Easa S.;Readi, Wadea A.;Idrees, Mohammed A.;Alshamrani, Saleh M.;Alwusaidi, Osama A.
    • International Journal of Computer Science & Network Security
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    • v.22 no.8
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    • pp.7-14
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    • 2022
  • This study aimed to test the factor structure of the measure of student participation in distance education. The study population consisted of all teachers in public education and faculty members in higher education in the Kingdom of Saudi Arabia by applying it to a sample of bachelor's and graduate students at the college of Education at umm al-Qura University. The (ESE) was applied to a random sample representing the study population consisting of (216) respondents. The results of the study showed that the scale consists of three main factors, with showed a high degree of construct validity through fit indices of the confirmatory factor analysis. The results have shown a gradual consistency of the measure's invariance that reaches the high level of the Measurement Invariance across the gender and study groups variables.

The Body Appreciation Scale-2: Validation of a Korean version among older adults (The Body Appreciation Scale-2의 노인 남녀 대상 한국어 타당성 검증 연구)

  • Minsun Lee
    • The Research Journal of the Costume Culture
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    • v.31 no.3
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    • pp.277-295
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    • 2023
  • The Body Appreciation Scale-2 (BAS-2) measures the extent to which individuals feel, accept, and respond to their own bodies in a positive manner. Given the research need to explore positive body image and its associations with various sociocultural factors and related consequences among individuals with various cultural backgrounds, several studies have established the psychometric properties and factor structures of the BAS-2 in different languages and samples with different characteristics. The current study investigated the psychometric properties and measurement invariance of a Korean version of the BAS-2 in an older Korean adult population (599 older Korean adults with the average age of 70 years). Data were collected using both online and offline (paper-based) survey questionnaires. The results of exploratory factor analyses and confirmatory factor analysis evidenced the unidimensional factor structure and measurement invariance of the Korean BAS-2 among older Korean men and women, after dropping item 1. Scalar invariance was supported across gender, and men and women did not significantly differ in observed mean scores of the Korean BAS-2. The results also supported good convergent validity and criterion validity. Incremental validity was demonstrated by predicting self-esteem over and above measures of age, BMI, subjective financial and health status, body esteem, and ageism. High internal reliability and test-retest reliability over a 2-week period were confirmed. Overall, the results of this study support the reliable use of a Korean BAS-2 to measure positive body image among older Koreans after excluding item 1.

The invariance principle for associated random fields

  • Kim, Tae-Sung;Seok, Eun-Yang
    • Journal of the Korean Mathematical Society
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    • v.31 no.4
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    • pp.679-689
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    • 1994
  • Let ${X_\underline{j} : \underline{j} \in Z^d}$ be a random field on some probability space $(\Omega, F, P)$ with $EX_\underline{j} = 0, EX_\underline{j}^2 < \infty$.

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SEVERAL PROPERTIES OF THE SUBCLASS OF Gk DESCRIBED BY SUBORDINATION

  • PARK, YOUNG OK
    • Honam Mathematical Journal
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    • v.21 no.1
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    • pp.139-147
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    • 1999
  • In this paper we generalize the definition of strongly close-to-convex functions by using the functions g(z) of bounded boundary rotation and investigate the distortion and rotation theorem, coefficient inequalities, invariance property and inclusion relation for the new class $G_{k}[A,\;B]$.

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