• 제목/요약/키워드: representative statistics

검색결과 252건 처리시간 0.022초

동적요인모형에 기반한 한국의 GDP 성장률 예측 (Forecasting Korea's GDP growth rate based on the dynamic factor model)

  • 이경서;임예지
    • 응용통계연구
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    • 제37권2호
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    • pp.255-263
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    • 2024
  • GDP는 한 나라의 가계, 기업, 정부 등 모든 경제 주체가 일정 기간 동안 창출한 재화와 서비스의 시장 가치의 합을 나타낸다. GDP를 통하여 국가의 경제 규모를 파악할 수 있으며, 정부의 정책 방향에 영향을 미치는 대표적인 경제 지표이므로 이에 대한 연구가 다양하게 이루어지고 있다. 본 논문에서는 G20 국가들의 주요 거시경제 지표를 활용하여 dynamic factor model 기반의 GDP 성장률 예측 모델을 제시하였다. 추출된 factor를 다양한 회귀분석 방법론과 결합하여 그 결과들을 비교하였으며, 기존의 전통적인 시계열 예측방법인 ARIMA 모델, common component를 이용한 예측 등도 함께 비교하였다. COVID 이후 지표의 변동성이 큰 점을 고려하여 예측 시기를 COVID 전후로 나누었으며, 그 결과 factor에 대해 ridge regression과 lasso regression을 적용하여 예측한 경우 가장 좋은 성능을 나타내었다.

직접측정치(直接測定値)와 간접측정치(間接測定値)의 결합(調合)에 의한 20대(代) 남성(男性) 상방신(上半身) 대표체형(代表體型) 연구( 硏究) (Representative Male Upper Body types of the 20s by the Combination of Direct and Indirect Measurement Values)

  • 이은지;심부자
    • 패션비즈니스
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    • 제11권4호
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    • pp.135-151
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    • 2007
  • This study is human body measurement of 200 adult males in their 20s by both direct and indirect methods in order to reveal the representative male upper body types. Composition factors of body types were classified while the combination of direct-indirect measurement values was chosen. The following are the findings: 1) The analysis of direct-indirect measurement statistics showed the following results: 173.80cm (height), 69.87kg (weight), 95.58cm (chest girth), $24.67^{\circ}$ (right shoulder angle), and $9.34^{\circ}$ (shoulder width angle). 2) The factor analysis of the body types by direct measurement produced 5 factors: 1 (front length of upper body), 2 (front length of upper body), 3 (back length of upper body), 4 (circumference of upper body), and 5 (shoulders length). These factors accounted for 90.08%. Also, the cluster analysis of factor scores led to 3 types: 1 (33%, short, comparatively wide shoulders and full in the hips), 2 (25.1%, well-developed upper body in tall, inversed triangle), 3 (41%, average height, short upper body). 3) The body-type factor analysis by indirect measurement resulted in 6 factors with the explanation of 83.24%: 1 (rear upper bady thickness), 2 (front upper body width), 3 (front chest thickness), 4 (left-right shoulder angle), 5 (front width of protrusion distance in chest and shoulders), and 6 (neck's front-rear side angle).In addition, the cluster analysis of factor scores brought about 4 types: 1 (15%, well-developed front chest, beardless waist), 2 (23.5%, flat chest, with shoulder, drooping shoulders, strait neck), 3 (39%, with shoulder, curved back), and 4 (22.5%, narrow and thin, curved waist). 4) Among the 118 subjects (75%), 58 subjects commonly appearing in indirect measurement values group and direct measurement values group were chosen the representative body type group according to asterisk indexes. They had the highest frequency in direct type 3 and indirect type 3, whose combination represented the physical characteristics of the representative body types.

국내 항타강관말뚝 설계법의 신뢰성평가 (Reliability Estimation of Static Design Methods for Driven Steel Pipe Piles in Korea)

  • 허정원;박재현;김경준;이주형;곽기석
    • 한국지반공학회논문집
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    • 제23권12호
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    • pp.61-73
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    • 2007
  • 본 논문에서는 국내 하중저항계수설계법 개발의 일환으로 구조물기초설계기준에 적용된 항타강관말뚝의 두 정역학적 지지력공식에 대하여 대표적인 신뢰성분석기법인 일차신뢰도법(FORM)과 몬테카를로 시뮬레이션(MCS)을 이용한 강도 높은 신뢰성해석을 수행하고 그 신뢰성수준을 평가하였다. 두 정역학설계법에 대한 저항편향계수는 대표 측정지지력과 설계지지력을 비교함으로써 평가하였다. 국내 정재하시험 및 지반조사 자료를 수집하여 말뚝의 측정 극한지지력을 결정하였고, 정역학적 지지력공식과 Meyerhof 경험식을 이용하여 설계 극한지지력을 산정하였다. 정확하고 효율적인 신뢰성평가를 위해 일차신뢰도법 및 몬테카를로 시뮬레이션 기반의 컴퓨터 프로그램을 개발하였다. 저항편향계수의 통계치를 이용하여 명시적 형태의 간편법인 평균일계이차모멘트법(MVFOSM)과 개선된 방법인 일차신뢰도법 및 몬테카를로 시뮬레이션에 의한 신뢰성해석을 수행하여 그 결과를 비교하였다. 또한 신뢰성 분석에 대한 주요 확률변수의 영향정도와 민감도를 파악하기 위하여 매개변수연구를 수행하였다.

A Coverage Function for Arbitrary Testing Profile and Its Performance

  • Park Joong-Yang;Fujiwara Takaji;Park Jae-Heung
    • International Journal of Reliability and Applications
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    • 제6권2호
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    • pp.87-99
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    • 2005
  • Coverage-based software reliability growth models (SRGMs) have been developed and successfully applied in practice. Performance of a coverage-based SRG M depends on the coverage function employed by the SRGM. When the coverage function represents the coverage growth behavior well irrespective of type of the testing profile the corresponding coverage-based SRGM is expected to be widely applicable. This paper first conducts a study of selecting the most representative coverage functions among the available coverage functions. Then their performances are empirically evaluated and compared. The result provides a foundation for developing widely applicable coverage-based SRGMs and monitoring the progress of a testing process.

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수학수업의 흥미유발을 위한 수학사 및 예화자료 연구 - 수학I을 중심으로 - (A Study on History of Mathematics and Illustrations for Interesting in Mathematics Classes - Centering on Mathematics I of Highschool -)

  • 이덕호;이만희
    • 한국학교수학회논문집
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    • 제3권1호
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    • pp.59-67
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    • 2000
  • This study has been done to help teach mathematics on the spot of education by providing the history of mathematics and illustrations concerning mathematics, which were rearranged for the level of the second grade students in highschool and intented to interest students in mathematics classes. The contents of teaching, according to each unit (Matrix, Sequence, Limit, Differentiation, Integration, Probability, Statistics) include the life of the representative mathematician, the historical background centered on episodes, questions linked with reality, questions making sensations in history and something for maxim in mathematics. If such contents are properly used, they are expected to be able to stimulate students' curiosity, and to be effective in improving students' learning ability in mathematics by causing them to show their active attitudes toward learning mathematics.

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Seasonal Variation of Cosmic Ray Intensity Observed by the Oulu Neutron Monitor

  • Jeong, Jaesik;Oh, Suyeon
    • Journal of Astronomy and Space Sciences
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    • 제37권3호
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    • pp.165-170
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    • 2020
  • Muons and neutrons are representative secondary particles that are generated by interactions between primary cosmic ray particles (mostly protons) and the nuclei of atmospheric gas compounds. Previous studies reported that muons experience seasonal variations because of the meteorological effects of temperature. The intensity of neutrons has a typical modulation with various periods and reasons, such as diurnal and solar variation or transient events. This paper reports that cosmic ray particles, which were observed by neutron monitors, have seasonal variations using the daily data at the Oulu neutron monitor. To eliminate the effects of solar activity across time, the daily data were normalized by two different transformations: transformations with respect to the grand mean and yearly mean. The data after transformation with respect to the yearly mean showed more statistical stability and clear seasonal variations. On the other hand, it is difficult to determine if the seasonal variation results from terrestrial effects, such as meteorological factors, or extraterrestrial effects, such as the position of the Earth in its orbit of revolution.

화학사고 원인분석을 통한 예방대책 수립에 관한 연구 (A Study on Prevention Measure Establishment through Cause Analysis of Chemical-Accidents)

  • 이형섭;임지표
    • 한국안전학회지
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    • 제32권3호
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    • pp.21-27
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    • 2017
  • Even if several chemical accident prevention systems such as PSM(Process Safety Management), RMP(Risk Management Plan), etc. have been carried out, many chemical accidents have still occurred at industrial plants in Korea. We describe the status of chemical industry and the trend of occurrence of chemical accidents in Korea. And this paper analyzes the recent chemical accidents in eight ways. These ways include chemical accident forms, ignition sources, sources of chemical equipment, human vs equipment/material causes, worker's working situation, employee scale, hazardous substances, week & time, fatalities of manufacture & contractor's workers. Finally we proposes the four representative prevention measures brought to result of cause analysis by accident statistics.

The Estimating Equations Induced from the Minimum Dstance Estimation

  • Pak, Ro-Jin
    • Journal of the Korean Data and Information Science Society
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    • 제14권3호
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    • pp.687-696
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    • 2003
  • This article presents a new family of the estimating functions related with minimum distance estimations, and discusses its relationship to the family of the minimum density power divergence estimating equations. Two representative minimum distance estimations; the minimum $L_2$ distance estimation and the minimum Hellinger distance estimation are studied in the light of the theory of estimating equations. Despite of the desirable properties of minimum distance estimations, they are not widely used by general researchers, because theories related with them are complex and are hard to be computationally implemented in real problems. Hopefully, this article would be a help for understanding the minimum distance estimations better.

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실시간 고차통계 정규화와 Smoothing 필터를 이용한 강인한 음성인식 (Robust Speech Recognition Using Real-Time High Order Statistics Normalization and Smoothing Filter)

  • 정주현;송화전;김형순
    • 대한음성학회:학술대회논문집
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    • 대한음성학회 2005년도 춘계 학술대회 발표논문집
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    • pp.91-94
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    • 2005
  • The performance of speech recognition is degraded by the mismatch between training and test environments. Many methods have been presented to compensate for additive noise and channel effect in the cepstral domain, and Cepstral Mean Subtraction (CMS) is the representative method among them. Recently, high order cepstral moment normalization method has introduced to improve recognition accuracy. In this paper, we apply high order moment normalization method and smoothing filter for real-time processing. In experiments using Aurora2 DB, we obtained error rate reduction of 49.7% with the proposed algorithm in comparison with baseline system.

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하천유역 수질 관측망 구성 연구 (Construction of Observational Locations for Measuring Water Quality in the River Area)

  • 권세혁;오현승
    • 산업경영시스템학회지
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    • 제35권3호
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    • pp.187-191
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    • 2012
  • The methods for constructing network of observational locations for measuring water quality in water reservoirs have been widely proposed, but they had some limitations to be applied to river areas, which lie in awkward clustering and finding representative observational locations among locations within each clustering. In this paper, a statistical approach to detect anomaly locations which were significantly different in important measurements for the water quality from the previous locations and construct observational network with them was proposed. Anomaly was detected with the sampling distribution of each primary principal component score, sum of primary PCs, or sum of residual PCs. The empirical study with the data of Nakdong Dam for guiding how to use our proposed approach and showing limitations of previous studied was described.