• 제목/요약/키워드: statistical variations

검색결과 490건 처리시간 0.024초

공적분벡터의 안정성에 대한 실증연구 (Statistical Tests and Applications for the Stability of an Estimated Cointegrating Vector)

  • 김태호;황성혜;김미연
    • 응용통계연구
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    • 제18권3호
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    • pp.503-519
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    • 2005
  • 공적분검정은 변수들간의 장기적 균형관계에 따른 공적분벡터가 표본기간 동안 일정하다는 가정하에서 실시된다. 따라서 기존의 연구들은 변수들 사이의 공적분관계를 안정적 장기균형관계로 해석해왔으나 장기균형관계가 존재해도 유일하지 않을 수 있으며, 표본기간 중 중요한 사건이 발생하는 경우 이러한 관계에 영향을 미처 안정성이 반드시 성립될 수 없다는 사실은 간과해왔다. 본 연구에서는 추정된 공적분벡터가 안정성을 유지하는가를 확인하기 위해 추가로 통계적 검정을 실시하였다. 공적분회귀모형 모수의 안정성을 검정하는 방식을 세분${\cdot}$체계화하여 공적분백터의 안정성 및 변동형태를 검색하는 실증분석에 적용시켜 보았다.

Gametogenic Cycle and the Number of Spawning Seasons by Quantitative Reproductive Analysis in Female Ruditapes philippinarum in Western Korea

  • Chung, Ee-Yung;Lee, Chang-Hoon;Choi, Ki-Ho;Choi, Moon-Sul;Lee, Ki-Young
    • 한국패류학회지
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    • 제26권3호
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    • pp.245-254
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    • 2010
  • For the studies of germ cell development and maturation in the ovary, the gametogenic cycle and the number of spawning seasons per year in female Ruditapes philippinarum were investigated by quantitative statistical analysis using an Image Analyzer System. Compared with the results by qualitative and quantitative analyses, monthly variations in female gonad indice by qualitative histological analysis showed a pattern similar to that of the female gametogenic cycle calculated by quantitative statistical analysis. The number of spawning seasons occurred once per year, from June to October. In quantitative statistical analysis using an image analyzer system, monthly changes in the portions (%) of the ovary area to total tissue areas in females increased in March and reached a maximum in May, and then showed a rapid decrease from June to October when spawning occurred. And also monthly changes in portions (%) of follicle areas to the ovary area and in portions of oocyte areas to ovarian tissue areas in females began to increase in March and reached a maximum in May, and then. rapidly dropped from June to October when spawnig occurred. From these data, it is apparent that the number of spawning seasons occurred once per year, from June to October. Monthly changes in the number of the oocyte per $mm^2$ and in mean diameter of the oocyte in captured image which were calculated for each female slide showed a maximum in May and reached the minimum from December to February. Therefore, female R. philippinarum showed a unimodal gametogenic cycle during the year.

지류하천의 유황분석을 통한 BOD5 농도변화 유형 분석 (Study of BOD5 Variation Patterns with Flow Regime Alteration in the Tributaries)

  • 정우혁;김영일;김홍수;문은호;박상현;이상진;정상만;조병욱;최정호
    • 한국물환경학회지
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    • 제27권4호
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    • pp.499-508
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    • 2011
  • We analyzed the variations of water quality with flow regime alterations to determine the characteristics of the stream where the stream management is considerably difficult due to the high variability of the flow rates. In this study, both flow rates and water qualities were monitored at the tributaries, 34 in count, of both Geum River and Sabgyo Lake Basins. The variation of water qualities were divided into 2 types, based on their stream flow rates, known as Type I and Type II. If the water quality of a stream increases during low flow rate periods compared with high flow rate periods, it is classified as Type I; if the water quality of the stream increases during high flow rate periods compared with low flow rate periods, it falls under Type II. The analysis for the variations of water qualities, of all 43 basins, resulted to 24 basins under Type I and Nineteen 19 basins under Type II. The variations of water qualities were analyzed first by using Regression Analysis followed by Statistical Analysis. The average slope of the variations of water qualities and the slope of the standard deviations were 0.00135 and 0.00477, respectively. The Probability Distributions of both Type I and Type II basins were 61.1% and 38.9%, respectively. The basin having a probability distribution of 61.1% and is also known as Type I, increases during periods of low flow rates, due to the presence of point sources. Therefore, the basin should be enforced with stream management. Before the stream management can be implemented in all streams falling under Type II, the sources of contaminants should first be estimated. These contaminants can be classified into two parts, the first is Point source pollution and the second is Non-point source pollution, where the Non-Point source pollution can be sub-divided into two types, with storm runoff and without storm runoff.

A Toposequence of Soils in the Karst of West-Central Florida, U.S.A

  • Banker, Laura;Reeder, Philip;Brinkmann, Robert
    • 동굴
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    • 제42권2호
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    • pp.41-63
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    • 1995
  • An abundance of information is available regarding soil horizons and their characteristics. Several methods can be used to gather and analyze this information. Through the use of qualitative analysis in the field, and laboratory and statistical analysis, a soil can be compared and analyzed with a great deal of scrutiny. Four soil pits were excavated in Citrus County Florida and samples were collected from each master horizon. Through the use of qualitative and quantitative analysis these samples were compared and analyzed in order to identify unique, as well as homogeneous features. It was determined that the soil profile designated Old Pit was different than other profiles because of landscape position and variations in parent material. Landscape position (ie. slope position) also influenced the genesis and evolution of the soils in the other three profiles(Profile 1, 2 and 3).

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Relationship between the Polymorphisms of 5' Regulation Region of Prolactin Gene and Milk Traits in Chinese Holstein Dairy Cows

  • Li, J.T.;Wang, A.H.;Chen, P.;Li, H.B.;Zhang, C.S.;Du, L.X.
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권4호
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    • pp.459-462
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    • 2006
  • Prolactin (PRL) plays an important role in promoting mammalian mammary gland development, and milk production during lactation. Therefore the PRL gene was chosen as a candidate gene for milk traits in Holstein dairy cows. PCR-SSCP and PCR-RFLP were used to analyze genetic variations in the 5' regulation region of the PRL gene. In this part of the gene, two new polymorphic sites were detected in the Chinese Holstein dairy cows. One was a XbaI-RFLP locus, and the other was an SSCP locus. Statistical analysis showed that the XbaI-RFLP locus and the SSCP locus had a significant positive effect on milk traits.

Clustering of 2D-Gel Images

  • Hur, Won
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XIII)
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    • pp.746-749
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    • 2003
  • Alignment of 2D-gel images of biological samples can visualize the difference of expression profiles and also inform us candidates of protein spots to be further analyzed. However, comparison of two proteome images between case and control does not always successfully identify differentially expressed proteins due to sample-to-sample variation. Because of poor reproducibility of 2D-gel electrophoresis, sample-by-sample variations and inconsistent electrophoresis conditions, multiple number of 2D-gel image must be processed to align each other to visualize the difference of expression profiles and to deduce the protein spots differentially expressed with reliability. Alignment of multiple 2D-Gel images and their clustering were carried out by applying various algorithms and statistical methods. In order to align multiple images, multiresolution-multilevel algorithm was found out to be suitable for fast alignment and for distorted images. Clustering of 12 different images implementing a k-means algorithm gives a phylogenetic tree of distance map of the proteomes. Microsoft Visual C++ was used to implement the algorithms in this work.

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식생분포에 따른 하도의 통수능 검토를 위한 3차원 모형의 적용 (Application of Three-Dimensional Model to Evaluate Stream Discharge Capacity due to Vegetation)

  • 노준우;이진영;안기홍
    • 환경영향평가
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    • 제20권1호
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    • pp.37-48
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    • 2011
  • Recently, the social and environmental functions of nature river are important due to the increase of expectation for river restoration. So it should be considered the effect of vegetation affecting the conveyance capacity and hydraulic resistance. However, it has not yet proposed a objective standard and modeling method to estimate the effect of conveyance capacity according to vegetaion distribution in the watercourse such as water level or velocity. Therefore, this study simulates the variations of water level and velocity using 3-dimensional hydrodynamic model, EFDC, to consider a conveyance capacity in downstream of the Soyang Reservoir. The simulation results were validated using statistical index such as F-test and T-test. As results, the water level rises about 0.01 to 0.47m and velocity difference are about -0.95m/s to 0.23m/s.

Z-axis Contact Detection Algorithm for a Wire Bonder using a Discrete Kalman Filter

  • Kim, Jung-Han
    • International Journal of Precision Engineering and Manufacturing
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    • 제8권1호
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    • pp.52-58
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    • 2007
  • We propose a new contact detection algorithm for fine pitch wire bonding. Fast and stable contact detection of the z-axis in wire bonding is extremely important to maintain the quality of fine pitch gold wire bonding processes, which use a small pad less than $70{\mu}m$ in diameter. A small perturbation in the contact detection time causes a large difference in the size of the formed squashed ball. The new detection method is based on a statistical approach and designed for a discrete Kalman filter. It is faster and has smaller detection time variations than conventional detection methods. Experimental results are presented to demonstrate the advantages of the proposed algorithm.

치차성능의 최적성과 강건성을 고려한 치차제원 및 치면수정의 설계 (Design of Gear Dimension and Tooth Flank Form for Optimal and Robust Gear Performance)

  • 배인호;정태형
    • 한국공작기계학회논문집
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    • 제13권4호
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    • pp.79-86
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    • 2004
  • Tooth errors inevitable in the manufacturing process have large effect on the strength/durability and vibration performances of gear drives. We show that the manufacturing errors affect the overall gear performances, especially vibration performance, and propose a robust optimal design method for gear dimension and its tooth flank form that guarantees reliable performances to the variation of manufacturing errors. This method begins with a search of optimal design candidates by using the previously developed gear optimal design method for the strength/durability and vibration performances. Then, the statistical analysis method is applied to find a robust design solution for the vibration performance which is generally very sensitive to the manufacturing variations.

소비자 선호 관점에서 본 차세대 무선 이동통신 단말기의 미래 (The Future of the New Mobile Telecommunication Terminal in the View of the Consumers' Preferences)

  • 김연배;이정동;고대영;김태유
    • 기술혁신연구
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    • 제12권1호
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    • pp.189-218
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    • 2004
  • In this paper, we estimate consumers' preferences for the key attributes of the future mobile telecommunication terminal using conjoint analysis. For statistical model, we estimate the mixed legit model which can reflect the heterogeneity of consumers' preferences, using the Bayesian approach with Gibbs sampling. The results show that there are large variations in consumers' preferences for the attributes of the future mobile telecommunication terminal, which justifies our using of mixed logit model. Also, the results show that most consumers prefer the medium size display and keyboard as input equipment. Additionally, far from general prediction, the results show that many consumers are indifferent to whether the future mobile telecommunication terminal is able to provide high quality internet service or not, and to operate many application programs and programs originally designed for PC. From those results, we can obtain some important implications for the R&D strategies. Additionally, the results on the heterogeneity of consumers' preferences reveal that it is possible that the complete device convergence may not happen.

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