• 제목/요약/키워드: Change point

검색결과 4,243건 처리시간 0.034초

Robust CUSUM test for time series of counts and its application to analyzing the polio incidence data

  • Kang, Jiwon
    • Journal of the Korean Data and Information Science Society
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    • 제26권6호
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    • pp.1565-1572
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    • 2015
  • In this paper, we analyze the polio incidence data based on the Poisson autoregressive models, focusing particularly on change-point detection. Since the data include some strongly deviating observations, we employ the robust cumulative sum (CUSUM) test proposed by Kang and Song (2015) to perform the test for parameter change. Contrary to the result of Kang and Lee (2014), our data analysis indicates that there is no significant change in the case of the CUSUM test with strong robustness and the same result is obtained after ridding the polio data of outliers. We additionally consider the comparison of the forecasting performance. All the results demonstrate that the robust CUSUM test performs adequately in the presence of seemingly outliers.

골격근의 지속적인 등척성 수축 시 발생하는 수축상태변화 추정 방법 (An Estimating Method of Contractile State Changes Come From Continuous Isometric Contraction of Skeletal Muscle)

  • 박형준;이승주
    • 대한전기학회논문지:시스템및제어부문D
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    • 제52권1호
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    • pp.55-63
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    • 2003
  • In this study was proposed that a new estimating method for investigation of contractile state changes which generated from continuous isometric contraction of skeletal muscle. The physiological changes(EMG, ECG) and the psychological changes by CNS(central nervous system) were measured by experiments, while the muscle of subjects contracted continuously with isometric contraction in constant load. The psychological changes were represented as three-step-change named 'fatigue', 'pain' and 'sick(greatly pain)' from oral test, and the method which compared physiological change with psychological change on basis of these three steps was developed. The result of analyzing the physiological signals, EMG and ECG signal changes were observed at the vicinity of judging point in time of psychological changes. Namely, it is supposed that contractile states have three kind of states pattern (stable, fatigue, pain) instead of two states (stable, fatigue).

Climate change and design wind load concepts

  • Kasperski, Michael
    • Wind and Structures
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    • 제1권2호
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    • pp.145-160
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    • 1998
  • In recent years, the effects of a possible climate change have been discussed in regard to wind loading on buildings and structures. Simple scenarios based on the assumption of global warming suggest an increase of storm intensities and storm frequencies and a possible re-distribution of storm tracks. Among recent publications, some papers seem to verify these scenarios while others deny the influence of climatic change. In an introductory step, the paper tries to re-examine these statements. Based on meteorological observations of a weather station in Germany, the existence of long-term trends and their statistical significance is investigated. The analysis itself is based on a refined model for the wind climate introducing a number of new basic variables. Thus, the numerical values of the design wind loads used in modern codes become more justified from the probabilistic point of view.

Townsend 방전영역의 불꽃전압에 미치는 음극표면상태의 영향 (The Influence of the Cathode Surface State on the Spark Voltage in the Townsend Discharge Domain)

  • 백용현
    • 전기의세계
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    • 제28권1호
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    • pp.73-82
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    • 1979
  • There are a great number of papers on the Townsend discharge in gases, and many of them are concerned with the effect of the cathode. It has been regarded that there are two kinds of effect of the electrodes, especially of the cathode; (a) the effect caused by the difference of the cathode material and (b) the effect by the change of the cathode surface state even in the same material. Both of them may change the secondary coefficient following after the change of the work function, and the atter may further change the primary ionization coefficient as foreign atoms on the surface may be dseorbed in sparks to decrease the purity of the gas. Thus the two effects must be investigated independently to study the roles of the cathode in gas discharges. In this report the effect of the cathode material on the sparking voltage is described. The experiment is also carried out under the condition that the desorption of impurities from the cathode be negligible. From these the new correlativity between the work function of the cathode and the sparking voltage is obtained. In addition, the interesting character of the minimum point of the Paschen's curve can be found.

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오일교환경보 알고리즘 및 표시장치 개발 (Development of Oil Change Warning Algorithm and Display Device)

  • 전상명
    • Tribology and Lubricants
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    • 제30권3호
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    • pp.168-176
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    • 2014
  • This paper presents an engine oil change warning algorithm based on the test results of a small dip-stick-gage-type engine-oil-deterioration-detection sensor, software to realize the algorithm and a display device to apply the software. The algorithm determines the engine oil deterioration condition from the rate of change in the dielectric constant based on the average measured capacitance at $80^{\circ}C$ after the engine stops. The rate of change in the dielectric constant at the time for oil change correlates with the time that one of recommended warning limits for engine oil physical properties such as TAN (Total Acid Number), TBN (Total Base Number) and viscosity is first reached. At this point, a warning signal for oil change appears on the display device like a smart-phone or individual display device. The frames of smartphone app have three stages. The user can directly input all of the thresholds into the frame of the smartphone app. The screen of the display device comprises one frame for each warning signature with the related message. The user can input the thresholds to the device through a USB cable connected to a personal computer.

기후변화에 따른 적응대책과 환경영향평가 (Review on Environmental Impact Assessment and Adaptation Strategies for Climate Change)

  • 최광호
    • 환경영향평가
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    • 제20권2호
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    • pp.249-256
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    • 2011
  • Causing by green house gas emission, global warming is being accelerated significantly. This global warming cause world climate to change quiet different than before and we call this phenomenon is Climate Change. Environmental Impact Assessment being implemented in Korea is to prevent predicted environmental impacts from deteriorating within the domestic information and situation. As the climate change is getting severe, new meteorological records can be occurred which is exceeded existing statistical data. According to KMA(Korea Meteorological Administration) data, maximum value of precipitation and temperature in many regions changed with new data within last decade. And these events accompanied with landslides and flooding, and these also affected on water quality in rivers and lakes. According to impacts by climate change, disasters and accidents from heavy rain are the most apprehensive parts. And water pollution caused by overflowed non-point sources during heavy rain fall, fugitive dust caused by long-term drought, and sea level rise and Tsunami may affect on seaside industrial complex should be worth consideration. In this review, necessity of mutual consideration with influences of climate change was considered adding on existing guideline.

기후변화로 인한 고온의 미래 사망부담 추정 (Estimation of Future Death Burden of High Temperatures from Climate Change)

  • 양지훈;하종식
    • 한국환경보건학회지
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    • 제39권1호
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    • pp.19-31
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    • 2013
  • Objectives: Elevated temperatures during summer months have been reported since the early 20th century to be associated with increased daily mortality. However, future death impacts of high temperatures resulting from climate change could be variously estimated in consideration of the future changes in historical temperature-mortality relationships, mortality, and population. This study examined the future death burden of high temperatures resulting from climate change in Seoul over the period of 2001-2040. Methods: We calculated yearly death burden attributable to high temperatures stemming from climate change in Seoul from 2001-2040. These future death burdens from high temperature were computed by multiplying relative risk, temperature, mortality, and population at any future point. To incorporate adaptation, we assumed future changes in temperature-mortality relationships (i.e. threshold temperatures and slopes), which were estimated as short-term temperature effects using a Poisson regression model. Results: The results show that climate change will lead to a substantial increase in summer high temperature-related death burden in the future, even considering adaptation by the population group. The yearly death burden attributable to elevated temperatures ranged from approximately 0.7 deaths per 100,000 people in 2001-2010 to about 1.5 deaths per 100,000 people in Seoul in 2036-2040. Conclusions: This study suggests that adaptation strategies and communication regarding future health risks stemming from climate change are necessary for the public and for the political leadership of South Korea.

차분한 시계열의 단순이동평균을 이용하여 조각별 선형 추세 모형을 추정하는 방법에 대한 연구 (A study on estimating piecewise linear trend model using the simple moving average of differenced time series)

  • 나옥경
    • 응용통계연구
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    • 제36권6호
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    • pp.573-589
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    • 2023
  • 조각별 선형 추세 모형에서의 변화점은 1차 차분한 시계열의 평균 변화점과 일치한다. 그러므로 1차 차분한 시계열의 평균 변화점을 탐색하면 조각별 선형 추세 모형의 변화점을 추정할 수 있다. 본 논문에서는 이와 같은 사실에 근거하여 원 시계열이 아닌 1차 차분한 시계열의 단순이동평균을 이용하여 원 시계열의 기울기가 변하는 변화점을 탐색하는 방법을 제안하고, 이에 대한 모의실험을 수행하였다. 모의실험 결과 본 논문에서 제안한 방법은 오차항들이 서로 독립인 경우뿐만 아니라 오차항들 사이에 강한 양의 자기상관이 존재하는 경우에도 변화점의 개수를 잘 추정하는 것으로 나타났다.

가상현실 콘텐츠를 활용한 인지재활프로그램 훈련이 뇌혈관질환 환자의 인지, 일상생활활동, 상지기능에 미치는 영향 (The Effectiveness of Cognitive Rehabilitation Program using Virtual reality content on Cognition, Activities of daily living, and Upper extremity functions in Cerebrovascular disease)

  • 조영석;김금숙;김영준;박진홍;이건호;백소영;황도연;권기현
    • 한국산학기술학회논문지
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    • 제21권8호
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    • pp.537-545
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    • 2020
  • 본 연구는 회복기 단계에 있는 뇌혈관 질환자를 대상으로 가상현실 콘텐츠를 활용한 인지재활프로그램의 임상적 적용 효과를 알아보았다. 연구방법은 회복기 단계의 뇌혈관 질환자 34명을 대상으로 대조군(16명)과 실험군(18명)으로 나눈 후에 가상현실 콘텐츠 기반의 인지재활프로그램을 적용한 후, 인지기능과 일상생활활동 능력, 상지기능에서의 효과를 비교하고자 하였다. 대조군에는 보편적인 재활치료 프로그램을 실시하고, 실험군에서는 보편적인 재활치료 프로그램과 가상현실 콘텐츠 기반의 인지재활프로그램을 제공하였다. 두 집단 모두 하루 2회(1회 30분씩)씩, 주 5회, 4주간(총 20회기) 실시하였다. 중재 결과, 두 집단 모두 일상생활활동 능력이 모두 유의미하게 향상되었지만(p<.05), 실험군에서의 변화량이 대조군보다 5점정도 더 향상되었다(p<.05). 인지기능에서도 실험군과 대조군이 유의미한 차이를 보였고(p<.05), 변화량에서 실험군이 대조군보다 2점정도의 변화 수치를 보였다(p<.05). 상지기능에서는 대조군과 실험군 간의 유의마한 차이는 없었고(p>.05), 전후 변화량을 비교한 결과 실험군이 대조군보다 0.7점정도 유의미한 변화폭을 보였다(p<.05). 가상현실 콘텐츠를 활용한 인지재활프로그램이 일반적인 재활치료 프로그램에 비해서 일상생활활동 능력과 인지기능에서의 유의미한 향상 폭의 차이가 있다는 것을 확인하는 연구였다.

기후변화의 위기와 기독교 생태교육의 방향 모색 (The Crisis of Climate Change and the Direction of Christian Ecological Education)

  • 조미영
    • 기독교교육논총
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    • 제67권
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    • pp.415-447
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    • 2021
  • 본 연구의 목적은 기후변화의 위기에 있어, 기독교교육이 생태학적 교육으로서 나아가야 할 방향을 모색해보는 데 있다. 기후변화가 보여주는 것은 불과 2-3도만 지구의 온도가 올라가도 생존이 불가능하다는 사실이다. 그러나 현재 우리의 모습은 삶을 변경하지 않는 한에서 기후변화의 위기를 염려하고 있다. 이를 위해 먼저 기후변화의 의미와 그 원인에 대해 살펴보았다. 인간중심주의적 세계관, 현대의 산업적, 과학기술적 성장, 그리고 소비지향적 사회구조 등을 그 원인으로 들 수 있는데, 인간중심주의적 세계관은 모든 것을 인간의 관점에서 정당화하며, 자연은 인간의 지배대상이나 하나의 도구로 간주해왔다. 또한 인간의 경제활동 규모가 커지면 커질수록 에너지 소비량은 증가하고, 이 증가에 따라 생태계 파괴의 위협도 증가한다. 개인의 소비증가와 풍요가 생태계 긴장을 가중시키는 것이다. 이러한 기후변화의 문제를 해결하기 위해서 성서 속의 창조를 통해 인간과 자연의 관계가 상생과 공존임을 규명하고, 안식의 원리를 통해 인간과 자연의 회복을 가져올 수 있으며, 성육신의 관점에서 세계를 하나님의 '몸'으로 이해하는 생태교육적 단초들을 발견하였다. 이 단초들을 토대로, 인간과 자연이 배려와 존중의 관계성을 가지는 생태적 패러다임으로의 전환, 창조영성의 회복, 청지기로서의 책임과 지구 차원의 연대를 이루어가기 위해 생태적 상상력의 함양을 제시함으로써 기독교 생태교육의 방향을 모색해보았다. 기후변화의 위기에 있어, 기독교의 생태교육적 단초들을 통한 기독교교육적 접근을 통해 지구의 회복이 이루어지고 책임적 존재로 다시금 설 수 있기를 기대해본다.