• 제목/요약/키워드: Statistical Change-point Analysis

검색결과 115건 처리시간 0.026초

실업률 변동구조의 분석과 전환점 진단 (An Analysis for the Structural Variation in the Unemployment Rate and the Test for the Turning Point)

  • 김태호;황성혜;이영훈
    • 응용통계연구
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    • 제18권2호
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    • pp.253-269
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    • 2005
  • 회귀모형의 기본가정은 추정된 계수들이 표본 내의 모든 관측값에 대해 일정하다는 것이다. 그러나 자료의 구조적 변화로 인해 모형의 추정계수 중 최소한 일부는 상이한 부분집합으로 전체 표본을 분할해야 하는 경우가 현실적으로는 흔히 존재한다. 본 연구에서는 두 회귀모형 계수들간의 동일성을 검정하는 방법을 확대${\cdot}$일반화하여 자료의 분할시점을 탐색하는 검정절차와 결합시킨 후 이를 최근 가장 큰 사회적 문제가 되고 있는 실업률의 구조변화 발생 여부와 시점을 판별하는 실증분석에 적용시켜 보았다.

전치부 개방교합을 동반한 골격성 제3급 부정교합 환자에 대한 양측 하악지 시상분할 골절단술후 안정성에 관한 임상적 분석 (CLINCAL ANALYSIS OF SKELETAL STABILITY AFTER BSSRO FOR CORRECTION OF SKELETAL CLASS III MALOCCLUSION PATIENTS WITH ANTERIR OPEN BITE)

  • 김현수;권대근;이상한;김진수;강동화;장현중
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제33권2호
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    • pp.152-161
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    • 2007
  • This study was conducted to patients visited oral maxillo-facial surgery, KNUH and the purpose of the study was to assess skeletal and dento-alveolar stability after surgical-orthodontic correction treated by skeletal Class III malocclusion patients with open bite versus non-open bite. This retrospective study was based on the examination of 40 patient, 19 males and 21 females, with a mean age 22.3 years. The patients were divided into two groups based on open bite and non-open bite skeletal Class III malocclusion patients. The cephalometric records of 40 skeletal Class III malocclusion patients (open bite: n = 18, non-open bite: n = 22) were examined at different time point, i.e. before surgery(T1), immediately after surgery(T2), one year after surgery(T3). Bilateral sagittal split ramus osteotomy was performed in 40 patients. Rigid internal fixation was standard method used in all patient. Through analysis and evaluation of the cephalometric records, we were able to achieve following results of post-surgical stability and relapse. 1. There was no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in maxillary occlusal plane angle of pre-operative stage(p>0.05). 2. Mean vertical relapses of skeletal Class III malocclusion patients with open bite were $0.02{\pm}1.43mm$ at B point and $0.42{\pm}1.56mm$ at Pogonion point. In skeletal Class III malocclusion patients with non-open bite, $0.12{\pm}1.55mm$ at B point and $0.08{\pm}1.57mm$ at Pogonion point. There was no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in vertical relapse(p>0.05). 3. Mean horizontal relapses of skeletal Class III malocclusion patients with open bite were $1.22{\pm}2.21mm$ at B point and $0.74{\pm}2.25mm$ at Pogonion point. In skeletal Class III malocclusion patients with non-open bite, $0.92{\pm}1.81mm$ at B point and $0.83{\pm}2.11mm$ at Pogonion point. There was no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in horizontal relapse(p>0.05). 4. There were no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in post-surgical mandibular stability(p>0.05). and we believe this is due to minimized mandibular condylar positional change using mandibular condylar positioning system and also rigid fixation using miniplate 5. Although there was no significant relapse tendency observed at chin points, according to the Pearson correlation analysis, the mandibular relapse was influenced by the amount of vertical and horizontal movement of mandibular set-back(p=0.05, r>0.304).

교통 접근성 변동에 따른 도시 토지이용 변화에 관한 연구 (A Study on the Change of Urban Land Use According to the Change of Transportation Accessibility)

  • 원석환;황철수
    • 지적과 국토정보
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    • 제47권1호
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    • pp.127-142
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    • 2017
  • 수도권의 도시화는 서울로의 교통 접근성의 변화에 따라 급속하게 진행되었다. 도시화 과정 속에 교외화, 주택 수의 증가, 도심용지 토지이용 증대 등의 다양한 공간적 변화가 이루어지고 있다. 본 연구의 목적은 2001~2008년 간 경기도 남양주시의 도시화 경관현상을 살펴보고 교통(도로 및 철도) 접근성의 변화에 따른 주변 토지이용 변화의 상관성을 분석하는데 있다. 상관성 분석 결과를 토대로 멀티 에이전트 시스템(MAS)을 이용하여 교통접근성과 토지이용 에이전트 간 상호작용의 관점에서 시뮬레이션 하였다. 이런 과정을 통하여 교통접근성의 변화로 인한 주변 토지이용 변화를 시공간적으로 예측하고자 한다. 도시화 현황을 살펴보기 위해서 위성영상 자료와 지적도 자료를 이용하여 거시적 미시적 경관 분석을 실시한 후 교통접근성의 변화에 따른 주변 토지이용 변화의 상관성을 분석하기 위해 교통자료와 토지이용 자료를 활용하여 GIS분석 및 통계 분석, 시뮬레이션 분석을 하였다. 본 연구를 통해 신규 도로 및 철도가 생성됨에 따라 주변 500m 이내에서 도심 토지용지로 변경되는 패턴을 확인할 수 있었으며, 향후 도로 및 철도가 생성됨에 따라 발생하는 토지용지 변화 현상을 예측할 수 있는 시스템을 구축하였다. 이를 통해 교통시설 입지 대상지역 선정 시 기초자료로 활용할 수 있는 근거가 될 수 있을 것으로 기대된다.

Trend analysis of rainfall characteristics and its impact on stormwater runoff quality from urban and agricultural catchment

  • Salim, Imran;Paule-Mercado, Ma. Cristina;Sajjad, Raja Umer;Memon, Sheeraz Ahmed;Lee, Bum-Yeon;Sukhbaatar, Chinzorig;Lee, Chang-Hee
    • Membrane and Water Treatment
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    • 제10권1호
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    • pp.45-55
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    • 2019
  • Climate change has significantly affected the rainfall characteristics which can influence the pollutant build-up and wash-off patterns from the catchment. Therefore, this study explored the influence of varying rainfall characteristics on urban and agricultural runoff pollutant export using statistical approaches. For this purpose, Mann-Kendall and Pettitt's test were applied to detect the trend and breakpoint in rainfall characteristics time series. In addition, double mass curve and correlation analysis were used to drive the relationship between rainfall-runoff and pollutant exports from both catchments. The results indicate a significant decreased in total rainfall and average rainfall intensity, while a significant increased trend for antecedents dry days and total storm duration over the study periods. The breakpoint was determined to be 2013 which shows remarkable trend shifts for total rainfall, average rainfall intensity and antecedents dry days except total duration. Double mass curve exhibited a straight line with significant rainfall-runoff relationship indicates a climate change effect on both sites. Overall, higher pollutant exports were observed at both sites during the baseline period as compared to change periods. In agricultural site, most of the pollutants exhibited significant (p< 0.05) association with total rainfall, average rainfall intensity and total storm duration. In contrast, pollutants from urban site significantly correlated with antecedent dry days and average rainfall intensity. Thus, total rainfall, average rainfall intensity and total duration were the significant factors for the agricultural catchment while, antecedents dry days and average rainfall intensity were key factors in build-up and wash-off from the urban catchment.

충격파치료를 이용한 상부 등세모근의 근막통증증후군 치료 (Extracorporeal Shock Wave Therapy for Myofascial Pain Syndrome of Upper Trapezius)

  • 이중호;정강훈;박영한
    • 대한물리의학회지
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    • 제7권2호
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    • pp.183-190
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    • 2012
  • Purpose : The purpose of this study was to evaluate whether extracorporeal shock wave therapy (ESWT) is an effective treatment for myofascial pain syndrome (MPS) of upper trapezius. Methods : Study subject were 20 patients (7 male and 13 female). The patients were evaluated by assessing of pain and function using visual analog scale (VAS) and pressure pain threshold (PPT) and Constant-Murley scale (CMS). Statistical analysis was used paired T-test to know significance probability between pre-test and post-test. Results : There was no statistical significance in the change in PPT. But, VAS scores were significantly improved after ESWT (p<.05). Using the Constant-Murley score, this study showed a significant decrease in pain and a significant increase in range of motion of shoulder (p<.05). Conclusion : These results indicate that extracorporeal shock waves therapy could be considered as an effective and efficient treatment modality for myofascial pain syndrome of upper trapezius.

삼각분할표에서 구조적 변화점 유무에 관한 검정 (Testing Structural Changes in Triangular Data)

  • 이성임
    • Communications for Statistical Applications and Methods
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    • 제15권4호
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    • pp.551-562
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    • 2008
  • 보험분야에서 지급준비금(loss reserve)을 추정할 때에는 보험사고의 발생년도와 사건발생 이후의 경과년도에 따라 지급된 보험금을 자료로 사용하게 되는데, 이것은 흔히 삼각분할표(run-off triangular table)의 형태로 주어진다. 이러한 삼각분할표 자료에 대하여 지급준비금 추정에 주로 사용되는 방법으로 사다리법(chain-ladder method)이 있는데, 이것은 사고발생년도부터 보험금이 정산되는 시점까지의 경과기간동안 지급된 누적 보험금의 변화율(진전계수)을 추정함으로써 지급준비금을 추정하는 것이다. 이러한 사다리법은 보험사고의 발생년도에 따른 진전계수의 변화가 없다는 가정을 기본전제로 하고 있다. 그러나 여러 가지 사회 환경적 요인으로 인하여 시간이 지남에 따라 지급보험금의 진전패턴이 달라질 수 있고, 본 논문에서는 사건의 변화에 따른 구조적 변화점 유무를 검정할 수 있는 검정법을 제안하고자 한다. 또한 이를 실제 예제에 적용 고찰해 보고자 한다.

생체 영상신호 측정을 통한 심장 수지침 효능 분석 (Efficiency Analysis of Cardiac Hand Acupuncture by Measuring the Bio-Image Signals)

  • 김봉현;조동욱
    • 한국산학기술학회논문지
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    • 제14권7호
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    • pp.3319-3325
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    • 2013
  • 본 논문에서는 일상생활에서 생활 의학의 한 방편으로 사용되고 있는 수지침이 실제 인체장기에 어떤 영향을 미치는지에 대해 IT 기술을 적용하여 이를 규명하는 연구를 행하고자 한다. 이를 위해 우선적으로 수지침 요법을 기반으로 인체에 있어 가장 중요한 장기인 심장을 대상으로 심장과 관련된 손 반사점인 A16 혈자리를 5분간 자극하여 전과 후의 얼굴 영상을 수집하고 Lab 색체계를 적용하여 심장과 연관된 이마와 입술 영역에 대한 색상 측정을 통해 상호간의 비교, 분석을 수행하였다. 최종적으로 생체 영상신호의 변화량 측정에 의해 A16 혈자리 자극으로 심장기능에 미치는 효과를 규명하는 연구를 수행하였으며 실험 결과 자료들에 대해 유의성 분석을 통해 실험 결과 자료가 유효한 결과 자료인지 여부에 대한 규명을 행하고자 한다.

일부 보건계열 대학생들의 심폐소생술 교육 전·후 비교 및 교육 후 수행능력에 미치는 영향 (A Change of the ability of CPR After educations for Some Health College Students and the factors Effects CPR Performance)

  • 박상섭;박대성;고종현;김영아;박재성
    • 한국응급구조학회지
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    • 제12권3호
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    • pp.17-26
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    • 2008
  • Purpose : This study aimed to make comparison before and after CPR training for health college students (departments of visual optics, occupational therapy, and health welfare administration). The questionnaire consisted of self-efficacy, knowledge, and attitudes toward CPR affect performance ability. Through this study, the researchers tried to provide basic data in developing of cardiopulmonary resuscitation training programs and training methods for health college students. Methods : This study was applied to 83 health college students (departments of visual optics, occupational therapy, and health welfare administration) in G Province. Data were collected from September 22 to October 9, 2008. Analysis was performed by using SPSS WIN 12.0 Version program. Frequency analysis, t-test, ANOVA, and Pearson's correlation coefficients were used. Statistical significance was based on p < .05. Results : 1. There was an increase with(${\rightarrow}$ in) 1.69 point before education and 3.01 after education of artificial ventilation(p < .001). There was an increase in 1.46 point before education and 3.24 after education of airway(p < .001). There was an increase in 1.54 point before education and 2.84 after education of chest compression location(p < .001). There was an increase in 1.97 point before education and 3.13 after education of chest compression(p < .001). 2. The difference between self-efficacy, knowledge, and attitude before and after CPR education, the self-efficacy increased from 2.08 point before education(p < .001 to 3.18 point after education. Knowledge increased from 2.09 point before education(p < .001) to 3.28 point after education. Attitude increased from 1.75 point before education(p < .001 to 3.05 point after education. 3. The correlation between self-efficacy, knowledge, and attitude toward CPR), was not changed before education. After education, knowledge showed quantitative correlation(r = .219, p < .05) with attitude. 4. In regression analysis with the aim of examining influence of self-efficacy, knowledge, and attitude upon performance ability, the effect wasn't given to performance ability before education. After education, the self-efficacy was indicated to have significant effect on performance ability(p < .05).

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혁신확산이론 기반의 CRM 품질요인과 성과에 관한 연구

  • 진찬용;김도관
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2008년도 추계 공동 국제학술대회
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    • pp.194-198
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    • 2008
  • Under the rapid change of business circumstance to E-business, CRM is one of the major strategic choices to reinforce the relationship with customers. In this point, this study attempts to understand the relationships among the quality of CRM and the variables of post adoption on the innovation diffusion theory. With integration of information system success model and innovation diffusion theory, it developed a research model and several hypotheses focusing on CRM performance of post-adoption. To testify the hypotheses, it conducted a survey on insurance industry and performed a statistical analysis for the research model with structure equation model. The results show that the factors of CRM quality (system, service, and information) have significant relationships with level of CRM usage and satisfaction. And the relationships between satisfaction and CRM performance and between CRM performance and intension of CRM extension are found as statistically significant.

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A convergence analysis of Block MADF algorithm for adaptive noise reduction

  • Min, Seung-gi;Young Huh;Yoon, Dal-hwan
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -1
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    • pp.377-380
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    • 2002
  • When it calculates the optimum price of filter coefficient, the many operation quantity is necessary. Is like that the real-time control is difficult and the hardware embodiment expense is big. The case which does not know advance information of input signal or the case where the statistical nature changes with change of surroundings environment is necessary the adaptive filter. Every hour to change a coefficient automatically and system in order to reach to the condition of optimum oneself, the fact that is the adaptive filter. When it does not the quality of input signal or it does not know the environment of surroundings every hour changing, it does not emit not to be, in order to collect, the fact that is the adaptive filter. The case of the Acoustic Echo Canceler does thousands filter coefficients in necessity. It reduces a many calculation quantity to respect, it uses the IIR filter from hour territory. Also it uses the block adaptive filter which has a block input signal and a block output signal. The former there is a weak point where the stability discrimination is always demanded. Consequently, The block adaptive filter is researched plentifully. This dissertation planned the block MADF adaptive filter used to MADf algorithm.

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