• 제목/요약/키워드: causal order

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실시간 환경을 위한 효율적인 인과순서 알고리즘 (An Efficient Causal Order Algorithm for Real-Time Environment)

  • 장익현
    • 정보처리학회논문지A
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    • 제12A권1호
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    • pp.23-30
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    • 2005
  • 인과순서 메시지 전달 알고리즘은 모든 전송되는 메시지가 인과순서로 전달되도록 한다. 인과순서를 유지하기 위해서는 전송되는 모든 메시지가 제어정보를 가지고 다녀야 하고, 제어정보의 크기는 관련된 프로세스의 수에 비례하여 커지게 되므로 제어정보의 크기를 줄이는 것은 분산시스템의 주요한 관심사가 되어 왔다. 본 논문에서는 실시간 성질을 가지는 멀티미디어 자료를 위한 효율적인 ${\Delta}$-인과순서 알고리즘을 제안하고 평가하였다. 제안된 알고리즘은 전송 부하를 줄이기 위하여 인과순서를 유지하는데 필수적이지 않은 정보를 가능한 이른 시기에 찾아내어 제거하며, 기존 알고리즘보다 훨씬 적은 전송부하를 가지게 된다.

전역통과 시스템에 대한 Deconvolution 필터링 기법 (Deconvolution Filtering Method for All-pass Systems)

  • 김성진
    • 한국정보통신학회논문지
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    • 제10권6호
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    • pp.1025-1031
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    • 2006
  • 본 논문에서는 FIR 근사를 기반으로한 전역통과 시스템에 대한 deconvolution 필터링 기법을 제안한다. 제안한 기법은 안정한 non-causal deconvolution 필터를 FIR 근사에 의해 안정한 causal deconvolution 필터로 변환시키는 것이다. 본 논문에서 보인바와 같이 전역통과시스템에 대한 deconvolution 필터의 임펄스 응답은 전역통과 시스템 자체의 임펄스 응답의 거울 영상(mirror image) 임을 알 수 있다. 이와 같이 전역통과 시스템에 대한 임펄스 응답과 그 시스템의 deconvolution 필터에 대한 임펄스 응답의 대칭성 때문에, 제안한 기법은 전역 통과 필터의 차수에 상관없이 동일하게 적용할 수 있다. 제안한 기법의 성능을 보이기 위하여 1차, 2차 및 400차의 전역통과 시스템에 대한 컴퓨터 시뮬레이션 결과를 포함한다.

류마티스 관절염 환자의 원인지각, 대응양상, 사회심리적 적응과의 관계 (Causal Perceptions, Coping Patterns and Psychosocial Adaptation in Rheumatoid Arthritis Patients)

  • 장세영;박상연
    • 근관절건강학회지
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    • 제9권2호
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    • pp.187-202
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    • 2002
  • This study was aim to provide rheumatoid arthritis patients the basic data of development of nursing intervention to help psychosocial adaptation of rheumatoid arthritis patients as exploring the relationship among causal perception, coping pattern, psychosocial adaptation of rheumatoid arthritis. As the results of this study the mean score of causal perception of the subjects was 3.37. The score of the internal-unstable was the highest. which was followed by extra-stable, internal factor, internal-stable, external factor and external-unstable in order among the factor of causal perception. The mean score of coping pattern was 2.64. The type of coping patterns the score of the receptive coping was the highest, which was followed by wishful coping active coping and negative coping in order among the type of coping pattern. The mean score of psychosocial adaptation was 3.28. The subconcept of psychosocial adaptation the score for personal relationship was the highest, which was followed by role function and mental state in order among the psychosocial adaptation. The analysis of the relation among causal perception, coping pattern and psychosocial adaptation showed significant negative correlation between causal perception and psychosocial adaptation(r=-0.3219, P=0.002). The analysis of the relation between the type of coping pattern and psychosocial adaptation showed significant negative correlation between psychosocial adaptation and active coping(r=-0.3210, P=0.002), negative coping(r=-0.2296, P=0.032). Only causal perception(-.36) and period of illness(-.26) effected on the psychosocial adaptation were shown to the negative direction significantly. The psychosocial adaptation was explained the 17% by these two variables. Based on this study results the factor of causal perception and the type of coping pattern of rheumatoid arthritis were shown significant relations between psychosocial adaptation. We suggests that nurses in practice apply to assessing the factor of causal perception of individuals illness and the type of coping patterns when nursing interventions in rheumatoid arthritis patients.

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인과지도의 타당성 확보와 정보 표현력 향상을 위한 연구 (A Study on Ensuring Validity and Increasing Power of Expression on Causal Maps)

  • 정재운;김현수
    • 한국시스템다이내믹스연구
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    • 제8권1호
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    • pp.97-115
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    • 2007
  • In System Dynamics, causal maps are used as a tool for analyzing dynamic problems and discussing the outcome of analyzed problems. However there are some limitations to use causal maps. In the drawing phase of causal maps, the high abstraction of variables that constitutes problems makes it difficult to find out correct information. And principles or rules to check errors on causal maps are not sufficient yet. Moreover, simulation modeling tasks are required to be concerned separately from drawing causal maps because causal maps cannot provide enough information to simulation modeling. In order to overcome these limitations, this study shows ways that ensure validity, increase power of expression of causal maps and improve the connection between causal maps and simulation modeling.

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Exploration of errors in variance caused by using the first-order approximation in Mendelian randomization

  • Kim, Hakin;Kim, Kunhee;Han, Buhm
    • Genomics & Informatics
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    • 제20권1호
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    • pp.9.1-9.6
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    • 2022
  • Mendelian randomization (MR) uses genetic variation as a natural experiment to investigate the causal effects of modifiable risk factors (exposures) on outcomes. Two-sample Mendelian randomization (2SMR) is widely used to measure causal effects between exposures and outcomes via genome-wide association studies. 2SMR can increase statistical power by utilizing summary statistics from large consortia such as the UK Biobank. However, the first-order term approximation of standard error is commonly used when applying 2SMR. This approximation can underestimate the variance of causal effects in MR, which can lead to an increased false-positive rate. An alternative is to use the second-order approximation of the standard error, which can considerably correct for the deviation of the first-order approximation. In this study, we simulated MR to show the degree to which the first-order approximation underestimates the variance. We show that depending on the specific situation, the first-order approximation can underestimate the variance almost by half when compared to the true variance, whereas the second-order approximation is robust and accurate.

칸트의 인과율 증명 (Kant's Proof of the Causal Principle)

  • 배정호
    • 철학연구
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    • 제147권
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    • pp.215-237
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    • 2018
  • 이 논문은 칸트가 "순수이성비판" 제2판 "경험의 유추들" 중 제2유추"에서 개진한 인과율 증명에 대한 연구이다. 본 논문은 이 증명과 관련된 칸트의 진술을 길잡이로 삼아 제2유추"의 인과율 증명을 단 하나의 통일적이고 타당한 선험적 증명임을 드러내고자 한다. 논문의 내용은 해당 텍스트의 분석을 통해 다음의 주장들을 정당화하는 것이다. 1. 제2유추"의 증명 대상은 보편 인과원리로서의 인과율이다. 다시 말해 여기서 증명되는 것은 모든 변화는 어떤 원인을 갖는다는 것만 말해 줄 뿐, 그 원인이 무엇인지는 말해 주지 않는 인과율이다. 2. 증명의 목표는 인과율에 따른 객관적인 시간적 잇따름의 가능성이다. 달리 말해 인과율 없이는 모든 변화의 시간 순서에 대한 객관적 규정이 불가능함을 보여주는 것이다. 3. 증명은 크게 보아 두 단계로 이루어진 하나의 논증 구조를 갖고 있다. 첫 단계는 분석적 증명으로서 객관적 변화에 대한 지각의 분석을 통해 인과율이 이 지각된 변화의 객관성을 위한 필요조건임을 증명한다. 이때 객관적 변화와 그것에 대한 지각의 가능성은 전제되어 있다. 이 전제는 둘째 단계에서 정당화된다. 둘째 단계는 종합적 증명으로서 객관적 변화와 그것의 경험적 인식 가능성을 이 가능성의 아프리오리한 조건들인 시간의 형식적 성질과 지성의 필연적인 종합 규칙(인과율)로부터 도출한다. 4. 칸트는 스트로슨의 비판과는 달리 지각 잇따름의 필연적인 규정성으로부터 상태 잇따름의 객관적(인과적) 규정성을 직접적으로 추론하는 것이 아니라, 부가적인 전제(지각 잇따름의 규정성은 지성의 아프리오리한 종합 규칙에 근거한다는 전제) 아래서 그렇게 한다. 따라서 칸트의 증명은 스트로슨이 비판한 '불합리한 추론'에 근거하고 있지 않다.

The Relationships between Product Quality Cues and Perceived Values based on Gender Differences at a Food Select Shop

  • Yim, Myung-Seong
    • 산경연구논집
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    • 제11권10호
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    • pp.59-73
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    • 2020
  • Purpose: The ultimate purpose of this work is to investigate gender differences in the relationships between product quality cues and perceived values at a food select shop. Specifically, this study examines the effects of internal and external cues, which are indicators of product quality, on emotional and social values based on gender differences. Research design, data and methodology: In this study, a questionnaire technique was used to collect the data necessary to test the proposed model. 183 data were collected through this technique. PLS SEM (Partial Least Squares Structured Equation Model) was used to test the research model. Results: First, there is no gender difference between intrinsic cue and emotional value. When using male and female data, there was no significant causal relationship between intrinsic cues and emotional values. Second, we found no gender difference between intrinsic cue and social value. When analyzed with female data, there was no significant causal relationship between intrinsic cue and social value. On the other hand, in the case of men, it was found that a weak causal relationship exists. Third, this study found gender difference between extrinsic cue and emotional value. In the case of men, it was found that a weak causal relationship exists, whereas in the case of women, a strong causal relationship exists between extrinsic cue and emotional value. Fourth, we found gender difference between extrinsic cue and social value. In the case of men, there was no causal relationship, whereas in the case of women, there was a strong causal relationship between extrinsic cue and social value. Finally, we found that there are moderating roles of gender in the relationship between external cues and perceived quality. Conclusions: As a result of analysis, it is necessary to focus on extrinsic clues of product in order to increase the perceived emotional and social values of women. On the other hand, in order to improve the perceived emotional and social values of men, it is necessary to pay attention to both intrinsic and extrinsic cues of product. Therefore, it is necessary to consider what clues and values are important to core customers.

도시보건소 공무원의 조직몰입도 인과요인에 관한 연구 - 한 가설적 인과모형분석을 통해 - (A Study on Causal Factors of Organizational Commitment of Public Servants in Urban Health Centers: Testing a Hypothetical Canusal Model)

  • 이상준;김창엽;김용익;신영수
    • 보건행정학회지
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    • 제8권1호
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    • pp.52-96
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    • 1998
  • To find causal factors and improvement plans of organizational commitment of public servants in urban health centers, a hypothetical causal model, which included 2 endogenous variables(organizational commitment & organizational satisfaction) and 15 exogenous variables, was constructed. Exogenous variables consisted of individual factors (sex, age, education, job-grade, and annual salary), psychological variables(pride for organization, extrinsic motivation, intrinsic motivation and support of supervisor) ad structural variables(formalization, centralization, communication, job-conflict, job-decision, and workload). In the hypothetical causal model, organizational commitment was supposed to be effect variable, and organizational satisfaction was presumed to be intervening variable to mediate between organizational commitment and exogenous variables. For data collection, cross-sectional self-administered questionnaire survey was conducted to 1,295 public servants from 32 urban health centers nationwide. The survey responses were from 934, 72.1% of subjects. But 756 responses(58.4%) were analyzed because of excluding ones with missing values. The hypothetical causal model was fitted by covariance structural analysis with maximum likelihood method. Main results were as follows: (1) The fitted causal model accounted for 33 and 55 percent of total variance of organizational commitment and organizational satisfaction of public servants, respectively. (2) In order of effect size, pride for organization, supervisor support, communication, extrinsic motivation and centralization had an indirect effect effect on organizational commitment through organizational satisfaction. However, the effect of centralization was negative. (3) Pride for organiztion, intrinsic motivation, organizational satisfaction, job-conflict, supervisor support, communication, age, centralization, annual salar and extrinsic motivation had indirect or direct effects on organizational commitment in order of effect size. Among them, effects of job-conflict and centraldization were negative. In conclusion, these results suggested that organizational commitment of public servants in urban health centers could be enhanced by pride for organization, intrinsic and extrinsic motivations, prevention of job-conflict and excess centralization, supervisor support and active communication. Especially, pride for organization and intrinsic motivation were expected to play the most important role.

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A Longitudinal Study on the Causal Association Between Smoking and Depression

  • Kang, Eun-Jeong;Lee, Jae-Hee
    • Journal of Preventive Medicine and Public Health
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    • 제43권3호
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    • pp.193-204
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    • 2010
  • Objectives: The objective of this study was to analyze the causal relationship between smoking and depression using longitudinal data. Methods: Two waves of the Korea Welfare Panel collected in 2006 and 2007 were used. The sample consisted of 14 426 in 2006 and 13 052 in 2007 who were aged 20 and older. Smoking was measured by smoking amount (none/$\geq$ two packs). Depression was defined when the summated CESD (center for epidemiological studies depression)-11 score was greater than or equal to 16. The causal relationship between smoking and depression was tested using logistic regression. In order to test the causal effect of smoking on depression, depression at year 2 was regressed on smoking status at year 1 only using the sample without depression at year 1. Likewise, smoking status at year 2 was regressed on depression at year 1 only using those who were not smoking at year 1 in order to test the causal effect of depression on smoking. The statistical package used was Stata 10.0. Sampling weights were applied to obtain the population estimation. Results: The logistic regression testing for the causal relationship between smoking and depression showed that smoking at year 1 was significantly related to depression at year 2. Smoking amounts associated with depression were different among age groups. On the other hand, the results from the logistic regression testing for the opposite direction of the relationship between smoking and depression found no significant association regardless of age group. Conclusions: The study results showed some evidence that smoking caused depression but not the other way around.

이동통신망을 위한 멀티캐스트 메시지 전달 알고리즘의 설계 및 평가 (Design and Evaluation of Multicast Message Delivery Algorithm for Mobile Networks)

  • 장익현
    • 한국콘텐츠학회논문지
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    • 제9권12호
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    • pp.537-545
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    • 2009
  • 본 논문에서는 이동통신망을 위한 효율적인 멀티캐스트 인과순서 알고리즘과 채널전환 프로토콜을 제안하였다. 메시지 전달 순서를 유지하기 위한 제어정보의 크기는 이동통신망에서의 채널전환과 메시지 전송성능에 큰 영향을 주므로 제어정보의 크기를 최소화할 필요가 있다. 이를 위해 모든 유효한 통신패턴을 분석하여 인과순서를 유지하는데 필수적이지 않은 중복정보를 가능한 이른 시기에 찾아내어 제거하고, 전송되는 제어정보를 최소화하는 채널전환 프로토콜을 사용하였다. 시뮬레이션을 통해 제안한 알고리즘이 기존의 알고리즘보다 더 좋은 성능을 보임을 보였다.