• Title/Summary/Keyword: Causality Test

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Factor Analysis of Seaborne Trade Volume Affecting on The World Economy (품목별 해상 물동량이 세계 경제에 미치는 영향 요인분석)

  • Ahn, Young-Gyun;Lee, Min-Kyu;Park, Ju-Dong
    • Korea Trade Review
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    • v.42 no.2
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    • pp.277-296
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    • 2017
  • More than 95% of imports and exports in the World are being transported by vessels. In other words, marine transportation accounts for a large portion of share in the world trade. The purpose of this study is to analyze factors of seaborne trade volume according to items affecting on the world economy. This study conducted a linear regression analysis between seaborne trade volume and the world economy (world GDP) to estimate the correlation between them. Panel data analysis and random effects model analysis have been applied to examine the effect of seaborne trade volume. For this study, the seaborne trade volume is categorized into 10 items, and estimated how much global GDP will be affected when the trade volume changes. In addition, the granger causality test was conducted to verify the relationship between seaborne trade volume and the world GDP. As a result, seaborne trade volume and the world GDP were mutually influenced each other. However, seaborne trade volume affects the world economy more significantly. The items affecting world economic growth include petroleum products, crude oil, chemical products, and so on. The estimated value of the coefficients of petroleum products, crude oil and chemical products were 1.014, 1.013 and 1.010, respectively. The estimated value 1.014 of petroleum products means that the growth rate is 1.014 times higher than the current world GDP growth rate when the seaborne trade volume of petroleum products increased by one unit Lastly, this study examines the seaborne trade volume of 10 categories and then verifies whether the growth rate of world GDP will increase when the volume of seaborne trade increased. This study is expected to provide policy-makers with useful information about formulating policies related to international trade.

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Development of a Testing Environment for Parallel Programs based on MSC Specifications (MSC 명세를 기반으로 한 병렬 프로그램 테스팅 환경의 개발)

  • Kim, Hyeon-Soo;Bae, Hyun-Seop;Chung, In-Sang;Kwon, Yong-Rae;Chung, Young-Sik;Lee, Byung-Sun;Lee, Dong-Gil
    • Journal of KIISE:Computing Practices and Letters
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    • v.6 no.2
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    • pp.135-149
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    • 2000
  • Most of prior works on testing parallel programs have concentrated on how to guarantee the reproducibility by employing event traces exercised during executions of a program. Consequently, little work has been done to generate test cases, especially, from specifications produced from software development process. In this research work, we devise the techniques for deriving test cases automatically from the specifications written in Message Sequence Charts(MSCs) which are widely used in telecommunication areas and develop the testing environment for performing module testing of parallel programs with derived test cases. For deriving test cases from MSCs, we have to uncover the causality relations among events embedded implicitly in MSCs. For this, we devise the methods for adapting vector time stamping to MSCs, Then, valid event sequences, satisfying the causality relations, are generated and these are used as test cases. The generated test cases, written in TTCN, are translated into CHILL source codes, which interact with a target module to be tested and test the validity of behaviors of the module. Since the testing method developed in this research work extracts test cases from the MSC specifications produced front telecommunications software development process, it is not necessary to describe auxiliary specifications for testing. In audition adapting vector time stamping generates automatically the event sequences, the generated event sequences that are ones for whole system can be used for individual testing purpose.

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Factor Analysis Affecting on Changes in Handysize Freight Index and Spot Trip Charterage (핸디사이즈 운임지수 및 스팟용선료 변화에 영향을 미치는 요인 분석)

  • Lee, Choong-Ho;Kim, Tae-Woo;Park, Keun-Sik
    • Journal of Korea Port Economic Association
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    • v.37 no.2
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    • pp.73-89
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    • 2021
  • The handysize bulk carriers are capable of transporting a variety of cargo that cannot be transported by mid-large size ship, and the spot chartering market is active, and it is a market that is independent of mid-large size market, and is more risky due to market conditions and charterage variability. In this study, Granger causality test, the Impulse Response Function(IRF) and Forecast Error Variance Decomposition(FEVD) were performed using monthly time series data. As a result of Granger causality test, coal price for coke making, Japan steel plate commodity price, hot rolled steel sheet price, fleet volume and bunker price have causality to Baltic Handysize Index(BHSI) and charterage. After confirming the appropriate lag and stability of the Vector Autoregressive model(VAR), IRF and FEVD were analyzed. As a result of IRF, the three variables of coal price for coke making, hot rolled steel sheet price and bunker price were found to have significant at both upper and lower limit of the confidence interval. Among them, the impulse of hot rolled steel sheet price was found to have the most significant effect. As a result of FEVD, the explanatory power that affects BHSI and charterage is the same in the order of hot rolled steel sheet price, coal price for coke making, bunker price, Japan steel plate price, and fleet volume. It was found that it gradually increased, affecting BHSI by 30% and charterage by 26%. In order to differentiate from previous studies and to find out the effect of short term lag, analysis was performed using monthly price data of major cargoes for Handysize bulk carriers, and meaningful results were derived that can predict monthly market conditions. This study can be helpful in predicting the short term market conditions for shipping companies that operate Handysize bulk carriers and concerned parties in the handysize chartering market.

Determinants of Eco-friendly Outdoor Wear Products Purchase Intention : Exploring Value-Belief-Norm Theory (친환경 아웃도어 웨어 제품 구매의도 결정요인 : 가치-신념-규범 이론을 중심으로)

  • Kim, Young Hwa;Oh, Kyung Wha;Jung, Hye Jung
    • Fashion & Textile Research Journal
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    • v.17 no.6
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    • pp.965-977
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    • 2015
  • This study aims to investigate determinants that included personal values, pro-environmental beliefs, and proenvironmental norms for enhancing consumers' purchase intention of eco-friendly outdoor wear exploring Stern(2000)’s the value-belief-norm theory. A survey was conducted with females and males between the ages of 20 and 60 who have experienced buying outdoor wear products. A total of 300 responses were analyzed by descriptive analysis, factor analysis, a reliability test, an independent samples t-test, and regression analysis. The results of this study were as follows: 1) The results of exploratory factor analysis and reliability test on the personal value clearly showed factorial structures including the social power, ecologic value, openness, equality, and altruistic value. 2) There are significant differences in personal value sub-dimensions, pro-environmental beliefs, pro-environmental norm, and purchase intention of eco-friendly outdoor wear products according to respondents' gender and age. 3) Personal values, but not social power, affect pro-environmental beliefs; in turn, pro-environmental beliefs affect pro-environmental norms, which then affects purchase intentions of eco-friendly outdoor wear. The findings support the conclusion that there is significant causality among personal value such as ecologic, openness, equality, and altruistic, pro-environmental belief, and pro-environmental norm. This study suggests pragmatic implications to understand outdoor wear consumers' socio-psychological and demographic factors and to augment purchase intentions of eco-friendly outdoor wear products.

The Influence of the Educational Environment of the Cooking Institute on the Educational Satisfaction and the Behavior Intention: Moderating Effect of Educational Period (조리교육학원의 교육환경이 교육만족도와 행동의도에 미치는 영향에 관한 연구: 교육기간 조절효과)

  • Lee, Seung-Hoo;Seo, Jeoung-Hee;Lee, Jong-Ho
    • Culinary science and hospitality research
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    • v.23 no.7
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    • pp.194-203
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    • 2017
  • The data collection and questionnaire survey were conducted from July 1, 2016, to August 30, 2016, and the final analysis was conducted with 273 copies. The collected data were analyzed using SPSS (V 23.0) and AMOS (V 21.0) programs. In order to identify the characteristics of the respondents, the frequency analysis was performed, and the reliability analysis and confirmatory factor analysis were performed for each measurement item. The conceptual reliability (CR) and standard variance extraction (AVE) values were calculated to verify the validity. Correlation analysis was conducted to measure the associations among the derived factors. For the hypothesis test, a structural equation modeling was used to test the jointness and organic causality of the whole model. In addition, an alternative model with a nested relationship with the basic model was set up to test the adjustment effect of the learner's educational environment on the educational satisfaction and behavioral intention. The purpose of the study was to examine the effect of educational environment on the educational satisfaction and behavioral intention of students at a cooking education institute in Busan. The implication of this study is that the operators of educational institutions should recognize the human factors as important means of marketing for the activation of cooking education and select instructors by applying more systematic and objective criteria when hiring instructors. Also, consideration should be given to support programs such as training programs and incentives to develop instructor's abilities. In addition, the positive educational outcomes of students may have a positive impact on financial performance, such as livelihood of other students and sales of educational institutions.

Relationship Changes of Financial Markets with Financial Development (금융시장 발전에 따른 금융변수간의 관계변화)

  • Chang, Byoung-Ky
    • The Korean Journal of Financial Management
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    • v.21 no.2
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    • pp.153-181
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    • 2004
  • This study is to explore whether the relationship among financial markets changed according to financial development. For this study, data analysis was conducted through analytic methods incorporated structural breaks such as Zivot and Andrews'(1992) unit root test Gregory and Hansen's(1996a,b) cointegration test, etc. In study results, it was found that dynamic relationship between stock price and interest rate was changed from negative to positive after the structural break(Oct 1999). It may be resulted from the fact that asset substitutability between stock and bond was increased since stock investment became popularized The negative relationship between stock price and exchange rate was reinforced after the structural break(the foreign currency crisis). Also, the negative relationship between interest rate and exchange rate was strengthened after the structural break(Oct. 1999).

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Analysis on the Relationship between the San-Nong Expenditure and 'Quality of Life' of Rural Residents in China (중국의 삼농(三農)지출과 농촌주민 '삶의 질'간 관계 분석)

  • Kim, Jong-Sup
    • International Area Studies Review
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    • v.20 no.1
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    • pp.237-250
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    • 2016
  • This paper is to explore the relationship between the San-Nong expenditure and Quality of life of rural residents in China for the period of 1978-2013, using the unit root test, the Granger causality test, the cointegration test, VAR model, and VECM. The results of a study on the relationship between two variables show that an obvious mutually causal relationship exits between the financial expenditure for San-Nong(san) and gross output value of agriculture, forestry, animal husbandry and fishery(apro) in China. But the case of per capita ploor space of newly built residential buildings in rural area(rho) and per capita consumption expenditure of rural households(rli) show that the financial expenditure for San-Nong(san) press for improvement in the quality of life of rural residence, while rho and rli have not yet apparent effect to san. On the other hand, It showed that the financial expenditure for San-Nong(san) and the number of medical personnel(prdo) do not have a causal relationship with each other. Therefore, the government needs to find ways for a variety of San-Nong expenditure to improve the quality of life of rural residents.

A Comparison of Predictive Power among Forecasting Models of Monthly Frozen Mackerel Consumer Price Models (냉동 고등어 소비자가격 모형 간 예측력 비교)

  • Jeong, Min-Gyeong;Nam, Jong-Oh
    • The Journal of Fisheries Business Administration
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    • v.52 no.4
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    • pp.13-28
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    • 2021
  • The purpose of this study is to compare short-term price predictive power among ARMA ARMAX and VAR forecasting models based on the MDM test using monthly consumer price data of frozen mackerel. This study also aims to help policymakers and economic actors make reasonable choices in the market on monthly consumer price of frozen mackerel. To analyze this study, the frozen wholesale prices and new consumer prices were used as variables while the price time series data were used from December 2013 to July 2021. Through the unit root test, it was confirmed that the time series variables employed in the models were stable while the level variables were used for analysis. As a result of conducting information standards and Granger causality tests, it was found that the wholesale prices and fresh consumer prices from the previous month have affected the frozen consumer prices. Then, the model with the highest predictive power was selected by RMSE, RMSPE, MAE, MAPE, and Theil's inequality coefficient criteria where the predictive power was compared by the MDM test in order to examine which model is superior. As a result of the analysis, ARMAX(1,1) with the frozen wholesale, ARMAX(1,1) with the fresh consumer model and VAR model were selected. Through the five criteria and MDM tests, the VAR model was selected as the superior model in predicting the monthly consumer price of frozen mackerel.

기업의 R&D 구조변화와 정부정책 방향에 대한 소고

  • 송종국;서환주
    • Journal of Technology Innovation
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    • v.11 no.1
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    • pp.79-97
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    • 2003
  • R&D expenditure of Korean firms has been increasing drastically since 1980 and occupied 84% of total R&D expenditure in 1994. After 1994, however, the growth rate of industry R&D expenditure has dropped below single digit. R&D concentration rate of upper 20 companies declined from 61.9% in 1999 to 49.8% in 2001. The technology trade balance has diverged by 2.8 billion dollars in 2000 compared to around 0.3 billion dollars in 1985. We find several reasons on declining the industry R&D growth rate in Korea. First, we carefully say there might be an crowding out effect in increasing government R&D investment from Granger causality test between industry R&D and government R&D. Second, the decreasing benefit of tax credit since 1992 on industry R&D expenditure has caused the decrease of industry R&D growth rate. Third, the type of R&D cost becomes to similar to matured countries type of cost, which means the portion of capital expenditure has been decreased since late of 1980s. Therefore, industry R&D growth rate gets to saturation point. We draw several policy implications from the changing structure of business R&D of Korean company. Firstly, to stimulate industry R&D investment Korean government needs to strengthen tax credit policy. Secondly, to induce foreign direct investment Korean government needs to establish technology infrastructures and high quality of manpower. To utilize foreign technology resources Korean government need to introduce global R&D program executed by foreign scientist as an Project Leader.

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A comparative study on J regional sport players' actual conditions of maxillofacial trauma and their knowledge about It (J지역 운동선수의 악안면 외상 실태와 지식에 관한 비교조사연구)

  • Choi, Mi-Hye;Kang, Eun-Ju;Woo, Seung-Hee
    • Journal of Korean society of Dental Hygiene
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    • v.10 no.4
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    • pp.695-703
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    • 2010
  • Objectives : The purpose of this study was to investigate the maxillofacial injuries of the sports players' and analyzing the concerned factor. Methods : The subject in this study were 290 sports players' enrolled in Jeolla region. SPSS statistics program(Version 12.0) was used to analyzed the collectde data, Chi-square test and percentage were used as the analysis technique. Results : 1. It was found that 63.8% of all respondents ever experienced trauma in sport activities and 28.6% experienced maxillofacial trauma. 2. In terms of traumatic causality, it was found that most of our respondents attributed the biggest cause of maxillofacial trauma to 'sport activities.' 3. However, it was found that only 12.1% of all respondents gave correct answers to question items about good medical treatment for traumatic odontoptosis. 4. It was found that less than half of all respondents ever faced information on maxillofacial trauma. Conclusions : This finding suggests that it is required to build up current orientation programs about maxillofacial trauma for our sport players. The maxillofacial trauma of sport players' is a important factor that degenerate the quality of the oral health and bring about the change of life style.