• 제목/요약/키워드: Causal Order

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인과적 순서 전달을 보장하는 전염형 그룹 통신 알고리즘 (Epidemic-Style Group Communication Algorithm ensuring Causal Order Delivery)

  • 김차영;안진호
    • 정보처리학회논문지A
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    • 제12A권2호
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    • pp.137-144
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    • 2005
  • 소 중규모 분산 시스템에서 기결정된 메시지 순서화 속성들을 만족시키기 위한 많은 신뢰성 있는 그룹통신 알고리즘들이 제안되었다. 그러나, 엄격한 신뢰성을 보장해야 하는 기존 알고리즘들은 대규모 시스템에 적합하지 않을 수 있다. 이러한 문제를 해결하기 위하여, 기존 알고리즘에 비해 합리적으로 보다 약한 신뢰성을 보장하는 동시에 확장성을 매우 향상시키기 위한 전염형 그룹통신 알고리즘들이 제안되었다. 이러한 알고리즘들은 모두 원자적 메시지 순서 전달 속성을 보장하도록 설계되었다. 그러나, 멀티미디어 시스템 및 협력 작업과 같은 분산 애플리케이션들이 보다 약한 메시지 순서 전달 속성인 인과적 순서 전달만을 요구한 수 있다. 따라서, 본 논문에서는 전염형 기법의 고유한 확장성을 유지하면서, 인과적 순서 전달을 보장하는 효율적인 전염형 그룹 통신 알고리즘을 제안한다.

만성관절염환자의 원인지각과 치료지시이행에 관한 연구 (A Study on the Relationship between Causual Perceptions and Compliance in Patients having Chronic Arthritis)

  • 임병주
    • 근관절건강학회지
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    • 제2권2호
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    • pp.168-184
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    • 1995
  • This deductive-survey study was undertaken in order to examine if there were relationship between causal perceptions, expectation for the cure and compliance. The sampling method was a non-probability, purposive sampling technique. The participants of this study was 195 volunteers 1) who have been diagnosed as having chronic arthritis and 2) who were at the rheumatis center of one university hospital in Seoul between September 18th to September 25th 1989. This instruments used for this study were the compliance scale developed by Choi and causal perception scale developed by the researcher. Analysis of data was done using pass analysis, Pearson correlation coefficient. The result of study were as follow : Hypothesis 1 : "It's correlated that causal perception, expectation for cure and compliance" was accepted. (F=4.85, p< .05) Hypothesis 2 : "It's correlated that causal perception, expectation for cure and with depression" was partially accepted. Total age group-worry and anxiety (r=.1580, p<.001) After 40-function of immunity (r=.1731, p<.05) warry and anxiety (r=.1730, p<.001). In the relationship between general characteristics and the variables, age group correlated with compliance and causal perception.

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잠재범주분석을 이용한 원인적 영향력 추론에 관한 연구 (Estimating Average Causal Effect in Latent Class Analysis)

  • 박가영;정환
    • 응용통계연구
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    • 제27권7호
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    • pp.1077-1095
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    • 2014
  • 관찰연구를 이용하여 인과관계를 추론할 경우 무작위 통제시험과는 달리 교란변수로 인한 편향을 제어하기 위한 통계적 전략이 필요하다. 최근에는 성향점수(propensity score) 를 이용한 짝짓기나 원인변수의 역확률을 가중치로 사용하는 주변구조모형이 제안되어 사용되고 있다. 이러한 인과관계 추론은 처치(treatment)가 명확히 주어진 경우에 교란변수를 통제하고 그 처치가 결과에 미치는 영향을 평가하는 방법에 초점이 맞추어져 있다. 하지만 기존의 방법의 경우 원인변수인 처치가 직접관측이 가능한 범주형 변수이고 결과변수 또한 직접관측이 가능한 변수인 경우에만 사용할 수 있는 한계를 갖고 있다. 본 연구에서는 원인변수인 처치와 결과변수의 결괏값의 직접적인 관측이 어려운 경우, 측정오차를 고려한 잠재범주모형(latent class analysis)의 변수로 모형화 함으로써 잠재범주 간의 원인적 영향력을 추정하는 방법을 제시하고자 한다. 그리고 미국의 The National Longitudinal Study of Adolescent Health 자료를 이용하여, 약물사용의 잠재범주에 대한 청소년기의 비행(delinquency)이라는 잠재범주의 원인적 영향력을 추정하였다.

BSC 성과측정지표간의 인과관계에 관한 연구 - C대학병원 사례 중심으로 - (A Study on Causal Relations among BSC Performance Measurement Indexes - Focused on the case of C University Hospital -)

  • 신승권
    • 산학경영연구
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    • 제20권2호
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    • pp.119-133
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    • 2007
  • 본 연구는 경영혁신의 한 기법으로 BSC를 비영리기업인 대학병원에 도입할 경우 영리기업에서와 같이 그 효과가 있는지를 검증하고자 한다. 대학병원 사례에 의한 BSC 성과측정지표간의 인과관계를 알아보기 위하여 구조방정식 모델을 이용하여 분석하였다. BSC 성과측정지표간의 인과관계를 분석한 결과 모두 통계적으로 유의한 것으로 나타나 연구가설이 모두 채택되었다. 향후에는 실제 재무자료를 학습 및 성장 관점, 내부프로세스 관점, 고객 관점과 연계하여 BSC 성과측정지표간의 인과관계를 연구할 필요가 있다.

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응급실을 내원한 흉통 환자의 원인질환에 따른 흉통의 질 및 관상동맥질환자의 흉통 표현 (Quality of Chest Pain According to Causal Diseases and Description of Chest Pain in Patients with Coronary Artery Diseases in Emergency Departments)

  • 천선희;최명애
    • 임상간호연구
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    • 제14권3호
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    • pp.61-72
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    • 2008
  • Purpose: The purpose was to identify quality of chest pain according to causal diseases and pain expression of patients with coronary artery diseases. Method: Participants were 1,964 patients with pain who visited the emergency department of A hospital from January to December 2006. Data were collected from nurses' and doctors' records as to causal disease, and quality and expression of chest pain. Results: Causal diseases were coronary artery diseases, non-specific chest pain, respiratory diseases, non-coronary artery heart diseases and digestive diseases in that order of frequency. Every disease except respiratory disease caused mostly dull and tract pain, but 63.7% of patients with coronary artery diseases complained of typical angina pain and 24.9% complained of atypical angina pain. Patients with coronary artery diseases mostly used word 'heaviness' in describing their dull pain, and 'squeezing' for tract pain. Both male and female patients who were diagnosed with coronary artery disease complained mostly frequently of dull pain and tract pain. Conclusion: The most common causal disease for patients with chest pain was coronary artery disease. Patients with other diseases also frequently complained of dull and tract pain, the same as patients with coronary artery diseases. A considerable number of patients complained various types of atypical angina pain in coronary artery diseases.

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Analysis for the Causal Relationship of Education Quality Factors in Korea

  • Lee, Jin-Choon;Lee, Hong-Woo
    • International Journal of Quality Innovation
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    • 제6권2호
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    • pp.147-166
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    • 2005
  • The purpose of this study is to analyze the causal relationship, in the perspective of Total Quality Management, among the education quality factors, which were suggested in the previous researches. Lee et al. [16] had tried to analyze the relationship among education factors, but they did not estimate the education factor using latent variable concept, which is very reasonable and efficient to represent the constructed concepts. So this study attempts to analyze the causal relationship among education quality factors, represented as latent variables used in structural equation modeling (SEM), and compared with each other. In this study, education quality factors were measured by several measures, constructed as several latent variables, and then processed with AMOS, the most efficient statistical package in the SEM area. In order to analyze the causal relationship among the education quality factors constructed as latent variables, this study designed the structural equation model with suggested factors and established several research hypotheses. This study discovered a prominent causality among the education quality factors, such as education leadership, student scholastic performance and satisfaction of education quality, which is similar to that of previous research. This outcome is really a unique Korean syndrome manifest within our educational career orientation.

Causality change between Korea and other major equity markets

  • Kwon, Tae Yeon
    • Communications for Statistical Applications and Methods
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    • 제25권4호
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    • pp.397-409
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    • 2018
  • The world financial markets are inter-linked in ways that varies according to market and time. We examine the causality of change focusing on the Korean market as related to the U.S. (S&P 500), Japan (Nikkei 225), Hong-Kong (HSI), and European (DAX) markets. In order to capture time-varying causality running from and to the Korea stock market, we apply the Granger causality test under a VAR model with a wild bootstrap rolling-window approach. We also propose a new concept of a significant causality ratio to measure the intensity of the Granger causality in each time unit. There are many asymmetric strengths in mutual Granger causal relationships. Moreover, there are cases with significant Granger causal relations only in one direction. The period with the most severe Granger causality both running from and to the KOSPI market is the GFC. The market that formed the two-way Granger causal relationship with the KOSPI market for the longest period is the S&P 500. The HSI and DAX markets have the strongest two-way Granger causal relationship with the KOSPI shortly after 2000, and the Nikkei market had the strongest two-way Granger causal relationship with the KOSPI market before the Asian financial crisis.

Recursive 디지털 필터 모델에 대한 역 필터링 기법 (An inverse filtering technique for the recursive digital filter model)

  • Sung-Jin Kim
    • 융합신호처리학회논문지
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    • 제5권2호
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    • pp.151-158
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    • 2004
  • 본 논문에서는 디지털 필터 모델에 대한 역 필터링 기법을 제안한다. 이 기법은 안정한 non-causal IIR 역 필터를 안정한 causal 역 필터로 변환(근사)시키는 것이다. 실제로 이 역 필터에 대한 FIR 근사 방법을 제안한다. 전역통과 시스템에 대한 역 필터의 임펄스 응답은 그 시스템에 대한 임펄스 응답의 거울 영상(mirror image) 임을 알 수 있다. 특히 전역통과 시스템에 대한 임펄스 응답이 이러한 대칭성을 갖기 때문에, 제안한 기법은 다른 시스템 보다 전역통과 시스템에 더욱 유용하다. 제안한 역 필터링 기법을 설명하기 위하여, 네 개의 예제를 제시한다. 그들 중 둘은 전역통과 필터에 대한 것이며, 다른 두 개의 예제는 IIR과 FIR 필터에 대한 것이다. 또한 컴퓨터 시뮬레이션을 통하여 제안한 기법이 잘 동작함을 보인다.

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Displacements, damage measures and response spectra obtained from a synthetic accelerogram processed by causal and acausal Butterworth filters

  • Gundes Bakir, Pelin;Richard, J. Vaccaro
    • Structural Engineering and Mechanics
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    • 제23권4호
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    • pp.409-430
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    • 2006
  • The aim of this study is to investigate the reliability of strong motion records processed by causal and acausal Butterworth filters in comparison to the results obtained from a synthetic accelerogram. For this purpose, the fault parallel component of the Bolu record of the Duzce earthquake is modeled with a sum of exponentially damped sinusoidal components. Noise-free velocities and displacements are then obtained by analytically integrating the synthetic acceleration model. The analytical velocity and displacement signals are used as a standard with which to judge the validity of the signals obtained by filtering with causal and acausal filters and numerically integrating the acceleration model. The results show that the acausal filters are clearly preferable to the causal filters due to the fact that the response spectra obtained from the acausal filters match the spectra obtained from the simulated accelerogram better than that obtained by causal filters. The response spectra are independent from the order of the filters and from the method of integration (whether analytical integration after a spline fit to the synthetic accelerogram or the trapezoidal rule). The response spectra are sensitive to the chosen corner frequency of both the causal and the acausal filters and also to the inclusion of the pads. Accurate prediction of the static residual displacement (SRD) is very important for structures traversing faults in the near-fault regions. The greatest adverse effect of the high pass filters is their removal of the SRD. However, the noise-free displacements obtained by double integrating the synthetic accelerogram analytically preserve the SRD. It is thus apparent that conventional high pass filters should not be used for processing near-fault strong-motion records although they can be reliably used for far-fault records if applied acausally. The ground motion parameters such as ARIAS intensity, HUSID plots, Housner spectral intensity and the duration of strong-motion are found to be insensitive to the causality of filters.

확장된 퍼지인식맵을 이용한 고장진단 시스템의 설계 (Design of fault diagnostic system by using extended fuzzy cognitive map)

  • 이쌍윤;김성호;주영훈
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.860-863
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    • 1997
  • FCM(Fuzzy Cognitive Map) is a fuzzy signed directed graph for representing causal reasoning which has fuzziness between causal concepts. Authors have already proposed FCM-based fault diagnostic scheme. However, the previously proposed scheme has the problem of lower diagnostic resolution. In order to improve the diagnostic resolution, a new diagnostic scheme based on extended FCM which incorporates the concept of fuzzy number into FCM is developed in this paper. Furthermore, an enhanced TAM(Temporal Associative Memory) recall procedure and pattern matching scheme are also proposed.

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