• 제목/요약/키워드: Hypothesis Tests

검색결과 349건 처리시간 0.025초

우리나라 저가항공 서비스의 만족이 재이용과 지역관광산업에 미치는 영향에 관한 연구 (A Study on the Satisfaction of Low-cost Carrier Service influence on Reuse and Local Tourism Industry in Korea)

  • 김효경;문재영
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2020년도 제61차 동계학술대회논문집 28권1호
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    • pp.109-110
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    • 2020
  • Today, the tourism industry, unlike the past, is fused with various fields and is closely related to various fields, not just one field. In the case of the tourism industry, it leads to an increase in product sales through not only national import but also enhancing national image, forming a positive virtuous chain. As mentioned in order to verify the hypothesis presented in this study, pilot tests were conducted on about 50 copies of the data, and as a result, in-flight service (H1), flight service (H2), compensation service (H3), and reservation service (H4) It has been shown to have a positive effect on customer satisfaction, and when customer satisfaction is achieved, it naturally leads to reuse.

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환경규제와 한국의 무역 (Environmental Regulations and Korean Trades)

  • 김일중;최문성
    • 자원ㆍ환경경제연구
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    • 제22권4호
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    • pp.785-815
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    • 2013
  • 본 논문은 중력모형을 이용해서 환경규제가 한국의 수출량, 총무역량 및 국제경쟁력에 어떤 영향을 미치는가를 규명해 보는 것이다. 고정효과 추정방법을 이용해서 전 산업, 비 환경오염산업, 16개 환경오염산업을 대상으로 추정하였으며, 자료는 한국과 교역량이 많은 120개 국가를 선정하여 2000년-2010년 사이의 산업패널자료와 환경성과지수(EPI)를 환경규제의 대리변수로 사용하였다. 분석 결과 한국과 교역상대국의 국내총생산량이 한국의 무역을 신장시키는데 큰 영향을 미친 변수라면, 교역상대국의 환경규제는 한국의 오염산업의 수출과 무역량을 감소시키고 국제경쟁력을 떨어뜨리는 무역장벽의 역할을 하는 것으로 나타났다. 그러나 분석기간 동안 비 오염산업에서는 이러한 환경규제효과가 극명하게 나타나지 않았다. 개별 산업에 대한 분석 결과 상당한 비중의 오염산업들이 교역상대국의 환경규제에 영향을 받는 것으로 나타났다. 이런 관점에서 동기간 사이에 한국의 무역에 있어서는 포터가설은 성립하지 않는 것으로 보인다.

Sex and Population Differences in Intelligence Are Partly Caused by Sexual Selection: Hn Evolutionary Hypothesis

  • Piffer, Davide
    • Interdisciplinary Bio Central
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    • 제6권4호
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    • pp.2.1-2.7
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    • 2014
  • Sexual dimorphism in intelligence suggests that this phenotype is a sexually selected trait. This view is supported by an overrepresentation (compared to the autosomal genome) of genes affecting cognition on the X chromosome. The aim of this study is to test the hypothesis that sexual selection can explain sex and country-level differences in performance on tests of fluid intelligence. Nationally representative samples from N = 44 countries were obtained from the Programme for International Student Assessment (PISA) Creative Problem Solving (CPS), which evaluates the core of intelligence, that is novel problem solving ability. Sexual selection has the double effect of increasing the prevalence of a favored phenotype and reducing genetic variation in sexually selected traits. Matching these predictions from evolutionary theory, the average country fluid intelligence is positively correlated to sexual dimorphism after partialling out per capita GDP and the latter in turn is inversely correlated to variance in intelligence scores within populations. Males have a higher variance than females but there is a negative correlation between male-female difference in variance and sexual dimorphism in intelligence, suggesting that selection reduces variance more in the selected sex. Average country male height is negatively correlated to sexual dimorphism in intelligence, a fact that supports the notion of a trade-off between physical and intellectual competition in the context of access to females. The results of this study, if replicated, imply that genome-wide association studies of cognition may benefit from a focus on sex chromosomes, which so far have been neglected. Another implication of this study is that intelligence has continued to evolve after different human populations migrated out of Africa and possibly up to the 19th century, as suggested by the substantial variability in sex differences even between neighbouring countries.

MBTI를 활용한 성장프로그램이 간호대학생의 대인관계 및 진로정체감에 미치는 효과 (Effects of a Ready Planned Self Growth Program through MBTI on Interpersonal Relationships and the Career Identity of Nursing College Students)

  • 권윤희;김정남
    • 지역사회간호학회지
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    • 제13권2호
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    • pp.216-229
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    • 2002
  • Objectives: This study was conducted to investigate the effects of a self growth program through MBTI on interpersonal relationships, and the career identity of nursing college students. Methods: A randomized controlled pre-post test experimental design was used for this study. The 24 nursing students were randomly assigned into two groups: 12 for the experimental group, and 12 for the control group. The subjects were junior nursing students, who were randomly selected from an undergraduate nursing program at K university located in Daegu, Korea. The data was collected from March 18 to April 1, 2002. The MBTI self growth program used in this study was based on the one developed by Shim and Kim (1997). The 12 experimental group students received the group self growth program through MBTI for 15 hours, while the 12 control group students received no treatment, except a series of tests. The Korean version MBTI test used in this study was developed and verified for reliability and validity by Kim and Sim (1990). Change in inter-personal relationships was measured using the Relationship Change Scale developed by Schlein and Guerney (1971), and modified by Lee and Mun (1982). Career identity was measured using the My Vocational Situation developed by Holland. Daiger and Power (1980), and revised by Kim (1997). The data were analyzed with the SPSS Win 10.0 program, through which the 2 test, t-test, and Repeated measures ANOVA were examined. Results: 1) The first hypothesis, 'the experimental group that received the self growth program through MBTI will obtain a higher interpersonal relationship score than the control group', was supported (F=5.295. p=.031. Interaction: p=.000). 2) The second hypothesis, 'the experimental group that received the self growth program through MBTI will obtain a higher career identity score than the control group', was supported (F=28.575, p=.000, Interaction: p=.000). Conclusion: The results showed that the ready planned self growth program through MBTI had positive effects on improving the interpersonal relationships, and the career identity of nursing college students.

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하이패스 DSRC 기반의 경로통행시간 산정을 위한 공간적 집계방안 산정에 관한 연구 (A Study on Spatial Aggregation Method for Path Travel Time Estimation using Hi-Pass DSRC System)

  • 이환필;심상우;최윤택;김동인
    • 한국도로학회논문집
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    • 제16권3호
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    • pp.119-129
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    • 2014
  • PURPOSES : This investigational survey is to observe a proper spatial aggregation method for path travel time estimation using the hi-pass DSRC system. METHODS : The links which connect the nodes of section detectors location are used for path travel time estimation traditionally. It makes some problem such as increasing accumulation errors and processing times. In this background, the new links composition methods for spatial aggregation are considered by using some types of nodes as IC, JC, RSE combination. Path travel times estimated by new aggregation methods are compared with PBM travel times by MAE, MAPE and statistical hypothesis tests. RESULTS : The results of minimum sample size and missing rate for 5 minutes aggregation interval are satisfied except for JC link path travel time in Seoul TG~Kuemho JC. Thus, it was additionally observed for minimum sample size satisfaction. In 15, 30 minutes and 1 hour aggregation intervals, all conditions are satisfied by the minimum sample size criteria. For accuracy test and statistical hypothesis test, it has been proved that RSE, Conzone, IC, JC links have equivalent errors and statistical characteristics. CONCLUSIONS : There are some errors between the PBM and the LBM methods that come from dropping vehicles by rest areas. Consequently, this survey result means each of links compositions are available for the estimation of path travel time when PBM vehicles are missed.

인터넷뱅킹과 은행의 경영성과 -실증분석을 중심으로- (The Impact of Internet Banking on the Performance of the Korean Banking Industry: An Empirical Analysis)

  • 김현욱;박창균
    • KDI Journal of Economic Policy
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    • 제25권2호
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    • pp.89-135
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    • 2003
  • 본 연구는 국내 은행산업에 급속히 확산되고 있는 인터넷뱅킹의 비용효율성 제고효과가 실제로 존재하며 궁극적으로 은행의 수익성을 개선시키는지를 은행별 재무자료를 통해 실증분석한 것이다. 분석의 결과, 인터넷뱅킹은 은행의 운영비용을 감소시키는 데 기여했지만 수익성 제고에는 별다른 영향을 미치지 못했음을 발견하였다. 이는 국내은행의 경우 인터넷뱅킹의 비용절감효과가 초기투자비용에 대한 부담을 완화할 수 있을 정도로 나타나고 있음을 의미하며, 다른 한편으로는 인터넷뱅킹이라는 혁신적 전달채널의 혜택이 은행의 이익보다는 고객들에 대한 우대금리 제공, 수수료 감면 등의 형태로 사회적 후생을 증대시키는 데 기여하였음을 암시한다. 이와 더불어, 본 연구에서는 국내은행 고객들의 대면거래에 대한 선호도가 높지 않다는 증거를 간접적으로나마 발견할 수 있었는데, 이는 앞으로 인터넷뱅킹 고객유지를 위한 은행의 간접비용 지출이 크게 줄어들면서 수익성이 제고될 것이라는 가설을 뒷받침하는 것이라 하겠다.

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Does the time interval after bleaching influence the adhesion of orthodontic brackets?

  • Nascimento, Glaucia Cristina Rodrigues;Miranda, Cyndi Albuquerque De;Machado, Sissy Maria Mendes;Brandao, Gustavo Antonio Martins;Almeida, Haroldo Amorim De;Silva, Cecy Martins
    • 대한치과교정학회지
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    • 제43권5호
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    • pp.242-247
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    • 2013
  • Objective: To test the null hypothesis that no difference exists between the effects of at-home bleaching and in-office bleaching on shear bond strength (SBS) with bracket bonding at 4 different time intervals after dental bleaching. Methods: Ninety extracted human premolars were randomly divided into 9 groups (n = 10) according to the bleaching methods used (at-home bleaching and in-office bleaching) and the storage time in artificial saliva (30 min, 1 day, 2 weeks, and 3 weeks before bonding). The control group was stored in artificial saliva for 7 days. Brackets were bonded with the Transbond XT adhesive system, and SBS testing was performed. The adhesive remnant index (ARI) was used to assess the amount of resin remaining on the enamel surfaces after debonding. The SBS data were analyzed by analysis of variance (ANOVA) and the Tukey test. For the ARI, the Kruskal-Wallis test was performed. Significance for all statistical tests was predetermined to be p < 0.05. Results: The SBS of the unbleached group was significantly higher (p < 0.05) than that of the bleached groups (except for the group bonded 30 min after at-home bleaching). Conclusions: The null hypothesis was not totally rejected. All bleaching groups tested had decreased SBS of the brackets to the enamel, except for the group bonded 30 min after at-home bleaching. The SBS returned to values close to those of the unbleached enamel within 3 weeks following bleaching.

헤지비율의 시계열 안정성 연구 (Random Walk Test on Hedge Ratios for Stock and Futures)

  • 설병문
    • 벤처창업연구
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    • 제9권2호
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    • pp.15-21
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    • 2014
  • 주식과 선물간의 헤지비율의 시계열 안정성에 대한 연구는 아직 찾아보기 어렵다. 본 연구는 KOSPI200과 S&P500의 주식과 선물 지수를 이용하여 한국과 미국, 두 금융시장의 헤지비율에 대한 시계열 안정성을 연구한다. Coakley, Dollery, and Kellard(2008)는 1995년부터 2005년의 S&P500 현물을 대상으로 시계열 안정성을 확인하였다. 본 연구는 선행연구에서 시계열 안정성이 검증된 기간을 분석기간에 포함하여 두 시장을 분석함으로써 연구결과의 강건성을 얻고자 한다. 한국시장의 분석기간은 주식선물시장이 개설된 1996년부터 2005년이다. S&P500은 1982년부터 2004년을 분석대상으로 하고 있다. 본 연구는 BEKK and diagonal-BEKK을 사용하여 헤지비율을 구하며, 시계열 안정성 검증을 위하여 R/S와 GPH 방법을 사용한다. 분석결과는 시장효율성의 이론적 근거가 되는 랜덤워크가설을 지지하지 않는다. 이 결과는 헤지비율을 이용한 위험관리 방안에 대한 시사점을 제공한다.

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Bayesian Model Selection in the Unbalanced Random Effect Model

  • Kim, Dal-Ho;Kang, Sang-Gil;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • 제15권4호
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    • pp.743-752
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    • 2004
  • In this paper, we develop the Bayesian model selection procedure using the reference prior for comparing two nested model such as the independent and intraclass models using the distance or divergence between the two as the basis of comparison. A suitable criterion for this is the power divergence measure as introduced by Cressie and Read(1984). Such a measure includes the Kullback -Liebler divergence measures and the Hellinger divergence measure as special cases. For this problem, the power divergence measure turns out to be a function solely of $\rho$, the intraclass correlation coefficient. Also, this function is convex, and the minimum is attained at $\rho=0$. We use reference prior for $\rho$. Due to the duality between hypothesis tests and set estimation, the hypothesis testing problem can also be solved by solving a corresponding set estimation problem. The present paper develops Bayesian method based on the Kullback-Liebler and Hellinger divergence measures, rejecting $H_0:\rho=0$ when the specified divergence measure exceeds some number d. This number d is so chosen that the resulting credible interval for the divergence measure has specified coverage probability $1-{\alpha}$. The length of such an interval is compared with the equal two-tailed credible interval and the HPD credible interval for $\rho$ with the same coverage probability which can also be inverted into acceptance regions of $H_0:\rho=0$. Example is considered where the HPD interval based on the one-at- a-time reference prior turns out to be the shortest credible interval having the same coverage probability.

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칼만필터에 기반한 GNSS 상시관측소 좌표 시계열의 지진에 따른 편의검출 기법에 관한 연구 (A Study on Online Detection Schemes of Earthquake Induced Shifts in Coordinate Time Series of GNSS Continuous Operation Reference Station by Kalman Filtering)

  • 이흥규
    • 한국산학기술학회논문지
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    • 제21권9호
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    • pp.662-671
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    • 2020
  • GNSS 상시관측소 고시좌표는 측지기준점으로써의 중요성과 다양한 위성측위 응용 분야의 활용성을 고려할 때 최고의 정확도와 최신성을 갖도록 관리해야 한다. 특히, 지진 등에 따른 지각 변위는 그 크기에 해당하는 만큼 기존 성과에 편의를 유발함으로, 그 영향이 목표 정확도를 초과할 때에는 신속히 새로운 기준 좌표를 산정·제공하는 등 적절한 조치가 필요하다. 본 논문에서는 GNSS 상시관측소 데이터 자동처리 시스템과 연계 구현할 수 있는 칼만 필터에 기반 좌표 시계열의 편의검출 절차와 방법을 연구하였다. 이를 통해 필터 이노베이션과 재추정 시계열에 적용할 수 있는 통계 검정 기법을 구현한 후 과학기술용 GNSS 소프트웨어에 의해 추정한 국내 14개소 상시관측소 2010년~2011년 시계열에 적용해 그 성능과 특징을 파악하였다. 그 결과 통계검정의 오류와 신뢰성을 고려할 때 필터링 시계열에 대한 CUSUM(Cumulative Sum) 검사는 지진 등에 따른 잔류편의 그리고 이노베이션에 대한 광역검정은 특정 에포크에서 발생하는 돌출오차 검출에 효과적인 것으로 분석되었다.