• Title/Summary/Keyword: causality model

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Impact of Debts on Economic Growth of Bangladesh: An Application of ARDL Model

  • Hossain, Muhammad Amir;Shirin, Shabnam
    • 아태비즈니스연구
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    • 제7권1호
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    • pp.1-10
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    • 2016
  • This study attempts to investigate the effects of different types of debts on economic growth in Bangladesh using time series data spanning from 2000 to 2015. In this study, the RDL model has been applied to determine the long run relationship among the selected variables. The result of the ARDL model shows that there exists a long term relationship between economic growth and the debt variables. It was evident from the findings that there exists bidirectional causality between public sector external debt and economic growth. Causality between private external debt and economic growth has been found to be insignificant. However, causality between domestic debt and economic growth showed a unidirectional causality from domestic debt to economic growth and not vice versa. Causality tests suggest that impact of domestic debt on economic growth is more effective compared to external debts.

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국방 R&D 투자 및 정부, 민간 R&D 투자와 국민소득간의 상호 인과관계 분석 (The Analysis of Granger Causality between GDP and R&D Investments in Government, Private, Defense Sectors)

  • 이진우;권오성
    • 한국국방경영분석학회지
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    • 제34권1호
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    • pp.79-98
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    • 2008
  • R&D 투자와 경제성장간의 관계에 대한 많은 기존 논의들은 R&D 투자가 경제성장에 대해 강한 양(+)의 관계가 존재함을 제시하고 있다. 그러나 투자와 성장사이의 강한 결합관계가 반드시 일방적 인과관계를 의미하는 것은 아니기 때문에 인과관계의 방향에 대한 보다 심층적인 연구가 필요하다. 특히 급변하는 안보환경 속에서 국방 R&D 투자가 증대되고 있음을 고려해 볼 때 국방 R&D 투자와 타 부문 R&D 투자 및 경제성장과의 결합관계에 대한 논의에 앞서 각 변수들 간의 인과관계에 대한 연구가 선행되어야 하나, 현재까지 국방 R&D 투자와 타 부문 간의 인과관계를 연구한 실적이 전무한 실정이다. 따라서 국방 R&D 투자와 다른 변수들과의 인과관계 분석을 통하여 국방 R&D 투자정책에 관한 정책적 시사점을 제시하였다는데 본 논문의 의미를 두고자 한다.

Towards Improving Causality Mining using BERT with Multi-level Feature Networks

  • Ali, Wajid;Zuo, Wanli;Ali, Rahman;Rahman, Gohar;Zuo, Xianglin;Ullah, Inam
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권10호
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    • pp.3230-3255
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    • 2022
  • Causality mining in NLP is a significant area of interest, which benefits in many daily life applications, including decision making, business risk management, question answering, future event prediction, scenario generation, and information retrieval. Mining those causalities was a challenging and open problem for the prior non-statistical and statistical techniques using web sources that required hand-crafted linguistics patterns for feature engineering, which were subject to domain knowledge and required much human effort. Those studies overlooked implicit, ambiguous, and heterogeneous causality and focused on explicit causality mining. In contrast to statistical and non-statistical approaches, we present Bidirectional Encoder Representations from Transformers (BERT) integrated with Multi-level Feature Networks (MFN) for causality recognition, called BERT+MFN for causality recognition in noisy and informal web datasets without human-designed features. In our model, MFN consists of a three-column knowledge-oriented network (TC-KN), bi-LSTM, and Relation Network (RN) that mine causality information at the segment level. BERT captures semantic features at the word level. We perform experiments on Alternative Lexicalization (AltLexes) datasets. The experimental outcomes show that our model outperforms baseline causality and text mining techniques.

철도기관사의 사고, 우울감, 인지실패 간의 인과관계 검증 (The Verification of Causality among Accident, Depression, and Cognitive Failure of the Train Drivers)

  • 노춘호;신택현
    • 한국시뮬레이션학회논문지
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    • 제25권4호
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    • pp.109-115
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    • 2016
  • 본 연구는 철도기관사에 의해 유발되는 사고와 우울감 및 인지실패 간의 관계를 '우울감 ${\rightarrow}$ 인지실패 ${\rightarrow}$ 사고'의 인과관계로 접근하는 연구모형 1과 '사고 ${\rightarrow}$ 우울감 ${\rightarrow}$ 인지실패'의 인과관계로 접근하는 연구모형 2로 설정하고 어느 모형이 타당한지를 구조방정식 모형으로 검증하였다. 현직 철도기관사 416명의 설문응답 유효데이터를 토대로 검증한 결과 후자의 연구모형, 즉 '사고 ${\rightarrow}$ 우울감 ${\rightarrow}$ 인지실패'의 인과관계에서 사고가 우울감을 매개로 하여 사고에 영향을 미친다는 점에서 모형 2가 통계적으로 타당하다는 결론을 도출하였다. 이 같은 연구결과는 인적오류와 관련하여 사고와 우울감의 인과관계 측면에서 접근하고 제도적인 개선방안을 함께 모색할 때 궁극적으로 기관사의 실수와 인지실패를 저감시킴으로써 인지실패로 인한 사고와 인적 오류의 확률을 그만큼 저감할 수 있다는 것을 시사한다.

Causality of Forest Inventory and Roundwood Supply in Korea

  • Kim, Dong-Jun;Kim, Eui-Gyeong
    • 한국산림과학회지
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    • 제95권5호
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    • pp.539-542
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    • 2006
  • This study confirmed econometrically the causality of forest inventory and roundwood supply using Korean data. In general, forest inventory is included as explanatory variable in roundwood supply function. We checked whether each series is stationary or not before using it in the model, and determined whether the combination of the series is comtegrated. The relationship between forest inventory and roundwood supply was represented by bivariate vector autoregressive model. The causality of forest evidence of the causal relationship between change in forest inventory and change in roundwood supply in Korea. That is, change in forest inventory does not cause change in roundwood supply in Korea. It seems reasonable not to include forest inventory as explanatory variable in roundwood supply function in Korea.

의류 구매자의 가치관-추구혜택-제품 속성간의 게층적 인과관계에 관한 탐색적 연구 (An Exploratory Research on Hierachical Causality of Personal Value, Benefits Sought and Clothing Product Attributes)

  • 안소현;서용한;서문식
    • 한국의류학회지
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    • 제24권5호
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    • pp.652-662
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    • 2000
  • Most of established study about consumer behavior was directly connected abstract value with concrete purchase behavior, nevertheless several recognizable process is intervened between abstract concept and concept behavior. Of course researchers suggest hierarchical causality through means-end chain model. However empirical study is insufficient. And it's not certain whether the consumer's personal value affects actual evaluation about product attributes. Thus the purpose of this paper was to explore hierarchical causality of personal value, benefits sought and clothing product attributes and to suggest an alternative approach method. For the empircial study the data sets were collected through 150 female consumers living in Pusan and SAS and LISREL VIII were used for statistical analysis. As the result, hierarchical causality suggested by means-end chain model was positively substantiated. That is, benefits sought is differentiated according to personal value, and actual product attributes are indirectly influenced by personal value through benefits sought. Benefits sought are found to be key mediating variables.

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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.

STATISTICAL CAUSALITY AND EXTREMAL MEASURES

  • Petrovic, Ljiljana;Valjarevic, Dragana
    • 대한수학회보
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    • 제55권2호
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    • pp.561-572
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    • 2018
  • In this paper we consider the concept of statistical causality in continuous time between flows of information, represented by filtrations. Then we relate the given concept of causality to the equivalent change of measure that plays an important role in mathematical finance. We give necessary and sufficient conditions, in terms of statistical causality, for extremality of measure in the set of martingale measures. Also, we have considered the extremality of measure which involves the stopping time and the stopped processes, and obtained similar results. Finally, we show that the concept of unique equivalent martingale measure is strongly connected to the given concept of causality and apply this result to the continuous market model.

Two-Dimensional Model of Hidden Markov Mesh

  • 신봉기
    • 한국HCI학회:학술대회논문집
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    • 한국HCI학회 2006년도 학술대회 1부
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    • pp.772-779
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    • 2006
  • The new model proposed in this paper is the hidden Markov mesh model or the 2D HMM with the causality of top-down and left-right direction. With the addition of the causality constraint, two algorithms for the evaluation of a model and the maximum likelihood estimation of model parameters have been developed theoretically which are based on the forward-backward algorithm. It is a more natural extension of the 1D HMM than other 2D models. The proposed method will provide a useful way of modeling highly variable image patterns such as offline cursive characters.

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Long-run and Short-run Causality from Exchange Rates to the Korea Composite Stock Price Index

  • LEE, Jung Wan;BRAHMASRENE, Tantatape
    • The Journal of Asian Finance, Economics and Business
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    • 제6권2호
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    • pp.257-267
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    • 2019
  • The paper aims to test long-term and short-term causality from four exchange rates, the Korean won/$US, the Korean won/Euro, the Korean won/Japanese yen, and the Korean won/Chinese yuan, to the Korea Composite Stock Price Index in the presence of several macroeconomic variables using monthly data from January 1986 to June 2018. The results of Johansen cointegration tests show that there exists at least one cointegrating equation, which indicates that long-run causality from an exchange rate to the Korean stock market will exist. The results of vector error correction estimates show that: for long-term causality, the coefficient of the error correction term is significant with a negative sign, that is, long-term causality from exchange rates to the Korean stock market is observed. For short-term causality, the coefficient of the Japanese yen exchange rate is significant with a positive sign, that is, short-term causality from the Japanese yen exchange rate to the Korean stock market is observed. The coefficient of the financial crises i.e. 1997-1999 Asian financial crisis and 2007-2008 global financial crisis on the endogenous variables in the model and the Korean economy is significant. The result indicates that the financial crises have considerably affected the Korean economy, especially a negative effect on money supply.